1.
Pantheon, Rome
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The Pantheon is a former Roman temple, now a church, in Rome, Italy, on the site of an earlier temple commissioned by Marcus Agrippa during the reign of Augustus. The present building was completed by the emperor Hadrian and probably dedicated about 126 AD and he retained Agrippas original inscription, which has confused its date of construction as the original Pantheon burnt down so it is not certain when the present one was built. The building is circular with a portico of large granite Corinthian columns under a pediment, a rectangular vestibule links the porch to the rotunda, which is under a coffered concrete dome, with a central opening to the sky. Almost two thousand years after it was built, the Pantheons dome is still the worlds largest unreinforced concrete dome, the height to the oculus and the diameter of the interior circle are the same,43.3 metres. Mary and the Martyrs but informally known as Santa Maria Rotonda, the square in front of the Pantheon is called Piazza della Rotonda. The Pantheon is a property, ruled by Italys Ministry of Cultural Heritage and Activities and Tourism through the Polo Museale del Lazio. The Pantheons large circular domed cella, with a temple portico front, is unique in Roman architecture. Nevertheless, it became a standard exemplar when classical styles were revived, Pantheon is derived from the Ancient Greek Pantheion meaning of, relating to, or common to all the gods. His uncertainty strongly suggests that Pantheon was merely a nickname, not the name of the building. In fact, the concept of a dedicated to all the gods is questionable. The only definite pantheon recorded earlier than Agrippas was at Antioch in Syria and it seems highly significant that Dio does not quote the simplest explanation for the name—that the Pantheon was dedicated to all the gods. Godfrey and Hemsoll maintain that the word Pantheon need not denote a group of gods, or, indeed, even all the gods. Certainly the word pantheus or pantheos, could be applicable to individual deities…, bearing in mind also that the Greek word θεῖος need not mean of a god but could mean superhuman, or even excellent. It seems likely that the Pantheon and the Basilica of Neptune were Agrippas sacra privata and this less solemn designation would help explain how the building could have so easily lost its original name and purpose in such a relatively short period of time. However, archaeological excavations have shown that the Pantheon of Agrippa had been destroyed except for the façade. Lise Hetland argues that the present construction began in 114, under Trajan and her argument is particularly interesting in light of Heilmeyers argument that, based on stylistic evidence, Apollodorus of Damascus, Trajans architect, was the obvious architect. The form of Agrippas Pantheon is debated and this description was widely accepted until the late 20th century. The only passages referring to the decoration of the Agrippan Pantheon written by an eyewitness are in Plinys Natural History, from him we know that the capitals, too, of the pillars, which were placed by M
2.
Rome
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Rome is a special comune and the capital of Italy. Rome also serves as the capital of the Lazio region, with 2,873,598 residents in 1,285 km2, it is also the countrys largest and most populated comune and fourth-most populous city in the European Union by population within city limits. It is the center of the Metropolitan City of Rome, which has a population of 4.3 million residents, the city is located in the central-western portion of the Italian Peninsula, within Lazio, along the shores of the Tiber. Romes history spans more than 2,500 years, while Roman mythology dates the founding of Rome at only around 753 BC, the site has been inhabited for much longer, making it one of the oldest continuously occupied sites in Europe. The citys early population originated from a mix of Latins, Etruscans and it was first called The Eternal City by the Roman poet Tibullus in the 1st century BC, and the expression was also taken up by Ovid, Virgil, and Livy. Rome is also called the Caput Mundi, due to that, Rome became first one of the major centres of the Italian Renaissance, and then the birthplace of both the Baroque style and Neoclassicism. Famous artists, painters, sculptors and architects made Rome the centre of their activity, in 1871 Rome became the capital of the Kingdom of Italy, and in 1946 that of the Italian Republic. Rome has the status of a global city, Rome ranked in 2014 as the 14th-most-visited city in the world, 3rd most visited in the European Union, and the most popular tourist attraction in Italy. Its historic centre is listed by UNESCO as a World Heritage Site, monuments and museums such as the Vatican Museums and the Colosseum are among the worlds most visited tourist destinations with both locations receiving millions of tourists a year. Rome hosted the 1960 Summer Olympics and is the seat of United Nations Food, however, it is a possibility that the name Romulus was actually derived from Rome itself. As early as the 4th century, there have been alternate theories proposed on the origin of the name Roma. There is archaeological evidence of occupation of the Rome area from approximately 14,000 years ago. Evidence of stone tools, pottery and stone weapons attest to about 10,000 years of human presence, several excavations support the view that Rome grew from pastoral settlements on the Palatine Hill built above the area of the future Roman Forum. Between the end of the age and the beginning of the Iron age. However, none of them had yet an urban quality, nowadays, there is a wide consensus that the city was gradually born through the aggregation of several villages around the largest one, placed above the Palatine. All these happenings, which according to the excavations took place more or less around the mid of the 8th century BC. Despite recent excavations at the Palatine hill, the view that Rome has been indeed founded with an act of will as the legend suggests in the middle of the 8th century BC remains a fringe hypothesis. Traditional stories handed down by the ancient Romans themselves explain the earliest history of their city in terms of legend and myth
3.
Roman Republic
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It was during this period that Romes control expanded from the citys immediate surroundings to hegemony over the entire Mediterranean world. During the first two centuries of its existence, the Roman Republic expanded through a combination of conquest and alliance, by the following century, it included North Africa, most of the Iberian Peninsula, and what is now southern France. Two centuries after that, towards the end of the 1st century BC, it included the rest of modern France, Greece, and much of the eastern Mediterranean. By this time, internal tensions led to a series of wars, culminating with the assassination of Julius Caesar. The exact date of transition can be a matter of interpretation, Roman government was headed by two consuls, elected annually by the citizens and advised by a senate composed of appointed magistrates. Over time, the laws that gave exclusive rights to Romes highest offices were repealed or weakened. The leaders of the Republic developed a tradition and morality requiring public service and patronage in peace and war, making military. Many of Romes legal and legislative structures can still be observed throughout Europe and much of the world in modern nation states, the exact causes and motivations for Romes military conflicts and expansions during the republic are subject to wide debate. While they can be seen as motivated by outright aggression and imperialism and they argue that Romes expansion was driven by short-term defensive and inter-state factors, and the new contingencies that these decisions created. In its early history, as Rome successfully defended itself against foreign threats in central and then northern Italy, with some important exceptions, successful wars in early republican Rome generally led not to annexation or military occupation, but to the restoration of the way things were. But the defeated city would be weakened and thus able to resist Romanizing influences. It was also able to defend itself against its non-Roman enemies. It was, therefore, more likely to seek an alliance of protection with Rome and this growing coalition expanded the potential enemies that Rome might face, and moved Rome closer to confrontation with major powers. The result was more alliance-seeking, on the part of both the Roman confederacy and city-states seeking membership within that confederacy. While there were exceptions to this, it was not until after the Second Punic War that these alliances started to harden into something more like an empire and this shift mainly took place in parts of the west, such as the southern Italian towns that sided with Hannibal. In contrast, Roman expansion into Spain and Gaul occurred as a mix of alliance-seeking, in the 2nd century BC, Roman involvement in the Greek east remained a matter of alliance-seeking, but this time in the face of major powers that could rival Rome. This had some important similarities to the events in Italy centuries earlier, with some major exceptions of outright military rule, the Roman Republic remained an alliance of independent city-states and kingdoms until it transitioned into the Roman Empire. It was not until the time of the Roman Empire that the entire Roman world was organized into provinces under explicit Roman control
4.
Roman Empire
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Civil wars and executions continued, culminating in the victory of Octavian, Caesars adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt. Octavians power was then unassailable and in 27 BC the Roman Senate formally granted him overarching power, the imperial period of Rome lasted approximately 1,500 years compared to the 500 years of the Republican era. The first two centuries of the empires existence were a period of unprecedented political stability and prosperity known as the Pax Romana, following Octavians victory, the size of the empire was dramatically increased. After the assassination of Caligula in 41, the senate briefly considered restoring the republic, under Claudius, the empire invaded Britannia, its first major expansion since Augustus. Vespasian emerged triumphant in 69, establishing the Flavian dynasty, before being succeeded by his son Titus and his short reign was followed by the long reign of his brother Domitian, who was eventually assassinated. The senate then appointed the first of the Five Good Emperors, the empire reached its greatest extent under Trajan, the second in this line. A period of increasing trouble and decline began with the reign of Commodus, Commodus assassination in 192 triggered the Year of the Five Emperors, of which Septimius Severus emerged victorious. The assassination of Alexander Severus in 235 led to the Crisis of the Third Century in which 26 men were declared emperor by the Roman Senate over a time span. It was not until the reign of Diocletian that the empire was fully stabilized with the introduction of the Tetrarchy, which saw four emperors rule the empire at once. This arrangement was unsuccessful, leading to a civil war that was finally ended by Constantine I. Constantine subsequently shifted the capital to Byzantium, which was renamed Constantinople in his honour and it remained the capital of the east until its demise. Constantine also adopted Christianity which later became the state religion of the empire. However, Augustulus was never recognized by his Eastern colleague, and separate rule in the Western part of the empire ceased to exist upon the death of Julius Nepos. The Eastern Roman Empire endured for another millennium, eventually falling to the Ottoman Turks in 1453, the Roman Empire was among the most powerful economic, cultural, political and military forces in the world of its time. It was one of the largest empires in world history, at its height under Trajan, it covered 5 million square kilometres. It held sway over an estimated 70 million people, at that time 21% of the entire population. Throughout the European medieval period, attempts were made to establish successors to the Roman Empire, including the Empire of Romania, a Crusader state. Rome had begun expanding shortly after the founding of the republic in the 6th century BC, then, it was an empire long before it had an emperor
5.
Concrete
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Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement that hardens over time. Most concretes used are lime-based concretes such as Portland cement concrete or concretes made with other hydraulic cements, when aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts chemically with the water and other ingredients to form a matrix that binds the materials together into a durable stone-like material that has many uses. Often, additives are included in the mixture to improve the properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials embedded to provide tensile strength, famous concrete structures include the Hoover Dam, the Panama Canal, and the Roman Pantheon. The earliest large-scale users of technology were the ancient Romans. The Colosseum in Rome was built largely of concrete, and the dome of the Pantheon is the worlds largest unreinforced concrete dome. Today, large concrete structures are made with reinforced concrete. After the Roman Empire collapsed, use of concrete became rare until the technology was redeveloped in the mid-18th century, today, concrete is the most widely used man-made material. The word concrete comes from the Latin word concretus, the passive participle of concrescere, from con-. Perhaps the earliest known occurrence of cement was twelve years ago. A deposit of cement was formed after an occurrence of oil shale located adjacent to a bed of limestone burned due to natural causes and these ancient deposits were investigated in the 1960s and 1970s. On a human timescale, small usages of concrete go back for thousands of years and they discovered the advantages of hydraulic lime, with some self-cementing properties, by 700 BC. They built kilns to supply mortar for the construction of houses, concrete floors. The cisterns were kept secret and were one of the reasons the Nabataea were able to thrive in the desert, some of these structures survive to this day. In the Ancient Egyptian and later Roman eras, it was re-discovered that adding volcanic ash to the mix allowed it to set underwater, similarly, the Romans knew that adding horse hair made concrete less liable to crack while it hardened, and adding blood made it more frost-resistant. Crystallization of strätlingite and the introduction of pyroclastic clays creates further fracture resistance, german archaeologist Heinrich Schliemann found concrete floors, which were made of lime and pebbles, in the royal palace of Tiryns, Greece, which dates roughly to 1400–1200 BC. Lime mortars were used in Greece, Crete, and Cyprus in 800 BC, the Assyrian Jerwan Aqueduct made use of waterproof concrete
6.
Cement
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A cement is a binder, a substance used in construction that sets, hardens and adheres to other materials, binding them together. Cement is seldom used solely, but is used to bind sand, Cement is used with fine aggregate to produce mortar for masonry, or with sand and gravel aggregates to produce concrete. Non-hydraulic cement will not set in wet conditions or underwater, rather, it sets as it dries and it is resistant to attack by chemicals after setting. Hydraulic cements set and become adhesive due to a reaction between the dry ingredients and water. The chemical reaction results in mineral hydrates that are not very water-soluble and so are quite durable in water and this allows setting in wet condition or underwater and further protects the hardened material from chemical attack. The chemical process for hydraulic cement found by ancient Romans used volcanic ash with added lime, the word cement can be traced back to the Roman term opus caementicium, used to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick supplements that were added to the burnt lime, to obtain a hydraulic binder, were referred to as cementum, cimentum, cäment. In modern times, organic polymers are used as cements in concrete. Non-hydraulic cement, such as slaked lime, hardens by carbonation in the presence of carbon dioxide which is present in the air. The carbonation reaction requires the dry cement to be exposed to air and this whole process is called the lime cycle. Conversely, hydraulic cement hardens by hydration when water is added, Hydraulic cements are made of a mixture of silicates and oxides, the four main components being, Belite, Alite, Tricalcium aluminate, Brownmillerite. The chemistry of the above listed reactions is not completely clear and is still the object of research, Cement, chemically speaking, is a product that includes lime as the primary curing ingredient, but is far from the first material used for cementation. The Babylonians and Assyrians used bitumen to bind together burnt brick or alabaster slabs, in Egypt stone blocks were cemented together with a mortar made of sand and roughly burnt gypsum, which often contained calcium carbonate. Lime was used on Crete and by the ancient Greeks, there is evidence that the Minoans of Crete used crushed potshards as an artificial pozzolan for hydraulic cement. A kind of powder which from natural causes produces astonishing results and it is found in the neighborhood of Baiae and in the country belonging to the towns round about Mt. Vesuvius. This substance when mixed with lime and rubble not only lends strength to buildings of other kinds, the Greeks used volcanic tuff from the island of Thera as their pozzolan and the Romans used crushed volcanic ash with lime. This mixture was able to set under water increasing its resistance, the material was called pozzolana from the town of Pozzuoli, west of Naples where volcanic ash was extracted. In the absence of ash, the Romans used powdered brick or pottery as a substitute
7.
Portland cement
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Portland cement is the most common type of cement in general use around the world, used as a basic ingredient of concrete, mortar, stucco, and most non-speciality grout. It was developed from other types of lime in England in the mid 19th century. It is a fine powder produced by heating materials in a kiln to form what is called clinker, grinding the clinker, and adding small amounts of other materials. Several types of Portland cement are available, with the most common being called ordinary Portland cement which is grey in color, Portland cement is caustic, so it can cause chemical burns. The powder can cause irritation or, with exposure, lung cancer and can contain some hazardous components such as crystalline silica. Concrete produced from Portland cement is one of the most versatile construction materials available in the world, Portland cement was developed from natural cements made in Britain beginning in the middle of the 18th century. Its name is derived from its similarity to Portland stone, a type of building stone quarried on the Isle of Portland in Dorset, England. In the late 18th century, Roman cement was developed and patented in 1796 by James Parker, Roman cement quickly became popular, in 1811 James Frost produced a cement he called British cement. James Frost is reported to have erected a manufactory for making of an artificial cement in 1826, in 1843, Aspdins son William improved their cement, which was initially called Patent Portland cement, although he had no patent. In 1818, French engineer Louis Vicat invented a hydraulic lime considered the principal forerunner of Portland cement. Edgar Dobbs of Southwark patented a cement of this kind in 1811, Portland cement was used by Joseph Aspdin in his cement patent in 1824 because of the cements resemblance to Portland stone. The name Portland cement is also recorded in a directory published in 1823 being associated with a William Lockwood, a Dave Stewart, however, Aspdins cement was nothing like modern Portland cement but was a first step in the development of modern Portland cement, called a proto-Portland cement. William Aspdin had left his fathers company and in his cement manufacturing apparently accidentally produced calcium silicates in the 1840s, in 1848, William Aspdin further improved his cement, in 1853, he moved to Germany, where he was involved in cement making. William Aspdin made what could be called meso-Portland cement, isaac Charles Johnson further refined the production of meso-Portland cement and claimed to be the real father of Portland cement. John Grant of the Metropolitan Board of Works in 1859 set out requirements for cement to be used in the London sewer project and this became a specification for Portland cement. The Hoffman endless kiln which gave control over combustion was tested in 1860. This cement was made at the Portland Cementfabrik Stern at Stettin and it is thought that the first modern Portland cement was made there. The Association of German Cement Manufacturers issued a standard on Portland cement in 1878, by the early 20th century American-made Portland cement had displaced most of the imported Portland cement
8.
Volcanic ash
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Volcanic ash consists of fragments of pulverized rock, minerals and volcanic glass, created during volcanic eruptions and measuring less than 2 mm in diameter. The term volcanic ash is often loosely used to refer to all explosive eruption products. Volcanic ash is formed during volcanic eruptions when dissolved gases in magma expand. The force of the escaping gas shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, once in the air, ash is transported by wind up to thousands of kilometers away. Volcanic ash is formed during volcanic eruptions, phreatomagmatic eruptions. Explosive eruptions occur when magma decompresses as it rises, allowing dissolved volatiles to exsolve into gas bubbles, as more bubbles nucleate a foam is produced, which decreases the density of the magma, accelerating it up the conduit. Fragmentation occurs when bubbles occupy ~70-80 vol% of the erupting mixture, when fragmentation occurs, violently expanding bubbles tear the magma apart into fragments which are ejected into the atmosphere where they solidify into ash particles. Fragmentation is an efficient process of ash formation and is capable of generating very fine ash even without the addition of water. Volcanic ash is produced during phreatomagmatic eruptions. During these eruptions fragmentation occurs when magma comes into contact with bodies of water groundwater, as the magma, which is significantly hotter than the boiling point of water, comes into contact with water an insulating vapor film forms. Eventually this vapor film will collapse leading to direct coupling of the cold water and this increases the heat transfer which leads to the rapid expansion of water and fragmentation of the magma into small particles which are subsequently ejected from the volcanic vent. Fragmentation causes an increase in area between magma and water creating a feedback mechanism, leading to further fragmentation and production of fine ash particles. Pyroclastic density currents can also produce ash particles and these are typically produced by lava dome collapse or collapse of the eruption column. Within pyroclastic density currents particle abrasion occurs as particles interact with each resulting in a reduction in grain size. In addition, ash can be produced during secondary fragmentation of pumice fragments and these processes produce large quantities of very fine grained ash which is removed from pyroclastic density currents in co-ignimbrite ash plumes. Physical and chemical characteristics of volcanic ash are primarily controlled by the style of volcanic eruption, another parameter controlling the amount of ash produced is the duration of the eruption, the longer the eruption is sustained, the more ash will be produced. The types of minerals present in volcanic ash are dependent on the chemistry of the magma from which it erupted, low energy eruptions of basalt produce a characteristically dark coloured ash containing ~45 - 55% silica that is generally rich in iron and magnesium
9.
Stucco
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Stucco or render is a material made of aggregates, a binder, and water. Stucco is applied wet and hardens to a dense solid. It is used as coating for walls and ceilings and as a sculptural. Stucco may be used to cover less visually appealing construction materials such as metal, concrete, cinder block, or clay brick and adobe. In English, stucco usually means a coating for the outside of a building, and plaster one for interiors, as described below, but other European languages, importantly including Italian, do not have the same distinction, stucco means plaster in Italian and serves for both. This has led to English often using stucco for interior decorative plasterwork in relief, especially in art history, the difference in nomenclature between stucco, plaster, and mortar is based more on use than composition. Animal or plant fibers were often added for additional strength, in the latter nineteenth century, Portland cement was added with increasing frequency in an attempt to improve the durability of stucco. At the same time, traditional lime plasters were being replaced by gypsum plaster, traditional stucco is made of lime, sand, and water. Modern stucco is made of Portland cement, sand, and water, lime is added to increase the permeability and workability of modern stucco. Sometimes additives such as acrylics and glass fibers are added to improve the properties of the stucco. This is usually done with what is considered a one-coat stucco system, lime stucco is a relatively hard material that can be broken or chipped by hand without too much difficulty. The lime itself is white, color comes from the aggregate or any added pigments. Lime stucco has the property of being self-healing to a degree because of the slight water solubility of lime. Portland cement stucco is very hard and brittle and can easily crack if the base on which it is applied is not stable, typically its color was gray, from the innate color of most Portland cement, but white Portland cement is also used. Todays stucco manufacturers offer a wide range of colors that can be mixed integrally in the finish coat. As a building material, stucco is a durable, attractive and it was traditionally used as both an interior and exterior finish applied in one or two thin layers directly over a solid masonry, brick or stone surface. The finish coat usually contained a color and was typically textured for appearance. The lath added support for the wet plaster and tensile strength to the brittle, cured stucco, while the increased thickness, the traditional application of stucco and lath occurs in three coats — the scratch coat, the brown coat and the finish coat
10.
Fresco
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Fresco is a technique of mural painting executed upon freshly-laid, or wet lime plaster. Water is used as the vehicle for the pigment to merge with the plaster, and with the setting of the plaster, the fresco technique has been employed since antiquity and is closely associated with Italian Renaissance painting. Buon fresco pigment mixed with water of temperature on a thin layer of wet, fresh plaster, for which the Italian word for plaster. Because of the makeup of the plaster, a binder is not required, as the pigment mixed solely with the water will sink into the intonaco. The pigment is absorbed by the wet plaster, after a number of hours, many artists sketched their compositions on this underlayer, which would never be seen, in a red pigment called sinopia, a name also used to refer to these under-paintings. Later, new techniques for transferring paper drawings to the wall were developed. The main lines of a drawing made on paper were pricked over with a point, the paper held against the wall, if the painting was to be done over an existing fresco, the surface would be roughened to provide better adhesion. This area is called the giornata, and the different day stages can usually be seen in a large fresco, buon frescoes are difficult to create because of the deadline associated with the drying plaster. Once a giornata is dried, no more buon fresco can be done, if mistakes have been made, it may also be necessary to remove the whole intonaco for that area—or to change them later, a secco. An indispensable component of this process is the carbonatation of the lime, the eyes of the people of the School of Athens are sunken-in using this technique which causes the eyes to seem deeper and more pensive. Michelangelo used this technique as part of his trademark outlining of his central figures within his frescoes, in a wall-sized fresco, there may be ten to twenty or even more giornate, or separate areas of plaster. After five centuries, the giornate, which were nearly invisible, have sometimes become visible, and in many large-scale frescoes. Additionally, the border between giornate was often covered by an a secco painting, which has fallen off. One of the first painters in the period to use this technique was the Isaac Master in the Upper Basilica of Saint Francis in Assisi. A person who creates fresco is called a frescoist, a secco or fresco-secco painting is done on dry plaster. The pigments thus require a medium, such as egg. Blue was a problem, and skies and blue robes were often added a secco, because neither azurite blue nor lapis lazuli. By the end of the century this had largely displaced buon fresco
11.
Caesarea Maritima
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Caesarea Maritima is an Israeli National Park in the Sharon plain, including the ancient remains of the coastal city of Caesarea. The city and harbor were built under Herod the Great during c, 22–10 BC near the site of a former Phoenician naval station known as Stratonos pyrgos. It later became the capital of Roman Judea, Roman Syria Palaestina. It was re-fortified by the Crusaders, and finally slighted by the Mamluks in 1265, the name Caesarea was adopted into Arabic as Qaysaria قيسارية. The location was all but abandoned in 1800, the ruins of the ancient city, on the coast just about 2 km south of modern Caesarea, were excavated in the 1950s and 1960s and the site was incorporated into a new national park in 2011. The site of the former Phoenician naval station was awarded to Herod the Great in 30 BC, Herod built his palace on a promontory jutting out into the sea, with a decorative pool surrounded by stoas. He went on to build a port and a city. In the year AD6, Caesarea became the civilian and military capital of Iudaea Province and the residence of the Roman procurator Antonius Felix. This city is the location of the 1961 discovery of the Pilate Stone and it is likely that Pilate used it as a base, and only went to Jerusalem when needed. It is also the location of Herods tomb. The city was described in detail by the 1st-century Roman Jewish historian Flavius Josephus, Josephus describes the harbor as being as large as the one at Piraeus, the major harbor of Athens. Remains of the buildings erected by Herod and the medieval town are still visible today, including the city walls, the castle. Caesarea grew rapidly, becoming the largest city in Judea, with a population of 125,000 over an urban area of 3.7 square kilometres. According to Josephus, the outbreak of the Jewish revolt of AD66 was provoked by Greeks of a merchant house in Caesarea sacrificing birds in front of a local synagogue. According to Josephus, Caesarea was the scene in AD26 of an act of civil disobedience to protest Pilates order to plant eagle standards on the Temple Mount of Jerusalem. The emperor Vespasian raised its status to that of a Colonia, in AD70, after the Jewish revolt was suppressed, games were held here to celebrate the victory of Titus. Many Jewish captives were brought to Caesarea Maritima, Kasher claims that 2,500 captives were slaughtered in gladiatorial games, Caesarea was one of four Roman colonies for veterans in the Syria-Phoenicia region. Caesarea is mentioned in the 3rd century Mosaic of Rehob, with respect to its non-Jewish population, when it was built in the 1st century BC, Sebastos Harbor ranked as the largest artificial harbor built in the open sea, enclosing around 100,000 m2
12.
Vitruvius
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His discussion of perfect proportion in architecture and the human body, led to the famous Renaissance drawing by Da Vinci of Vitruvian Man. By his own description Vitruvius served as an artilleryman, the class of arms in the military offices. He probably served as a officer of artillery in charge of doctores ballistarum. Little is known about Vitruvius life, most inferences about him are extracted from his only surviving work De Architectura. Even his first name Marcus and his cognomen Pollio are uncertain. Cetius Faventinus writes of Vitruvius Polio aliique auctores, this can be read as Vitruvius Polio, and others or, less likely, as Vitruvius, Polio, Vitruvius was a military engineer, or a praefect architectus armamentarius of the apparitor status group. He is mentioned in Pliny the Elders table of contents for Naturalis Historia, frontinus refers to Vitruvius the architect in his late 1st-century work De aquaeductu. Likely born a free Roman citizen, by his own account, Vitruvius served the Roman army under Caesar with the otherwise poorly identified Marcus Aurelius, Publius Minidius and these names vary depending on the edition of De architectura. Publius Minidius is also written as Publius Numidicus and Publius Numidius, as an army engineer he specialized in the construction of ballista and scorpio artillery war machines for sieges. It is speculated that Vitruvius served with Caesars chief engineer Lucius Cornelius Balbus, the locations where he served can be reconstructed from, for example, descriptions of the building methods of various foreign tribes. Although he describes places throughout De Architectura, he not say he was present. His service likely included north Africa, Hispania, Gaul and Pontus, the position of the camp, the direction of the entrenchments, the inspection of the tents or huts of the soldiers and the baggage were comprehended in his province. His authority extended over the sick, and the physicians who had the care of them and he had the charge of providing carriages, bathhouses and the proper tools for sawing and cutting wood, digging trenches, raising parapets, sinking wells and bringing water into the camp. He likewise had the care of furnishing the troops with wood and straw, as well as the rams, onagri, balistae, at various locations described by Vitruvius, battles and sieges occurred. He is the source for the siege of Larignum in 56 BC. The broken siege at Gergovia in 52 BC, and the siege of Uxellodunum in 51 BC. These are all sieges of large Gallic oppida, a legion that fits the same sequence of locations is the Legio VI Ferrata, of which ballista would be an auxiliary unit. Mainly known for his writings, Vitruvius was himself an architect, frontinus mentions him in connection with the standard sizes of pipes
13.
De architectura
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It contains a variety of information on Greek and Roman buildings, as well as prescriptions for the planning and design of military camps, cities, and structures both large and small. Derived partially from Latin rhetoric, Vitruvian terms for order, arrangement, proportion, and fitness for intended purposes have guided architects for centuries, the Roman author also gave advice on the qualifications of an architect and on types of architectural drawing. The ten books or scrolls are organized as follows, De architectura – Ten Books on Architecture Roman architects were skilled in engineering, art, Vitruvius was very much of this type, a fact reflected in De architectura. He covered a variety of subjects he saw as touching on architecture. This included many aspects that may seem irrelevant to modern eyes, ranging from mathematics to astronomy, meteorology, in the Roman conception, architecture needed to take into account everything touching on the physical and intellectual life of man and his surroundings. Vitruvius, thus, deals with many issues concerning architecture. Book IX relates the abstract geometry of Plato to the work of the surveyor. Astrology is cited for its insights into the organisation of human life, likewise, Vitruvius cites Ctesibius of Alexandria and Archimedes for their inventions, Aristoxenus for music, Agatharchus for theatre, and Varro for architecture. Vitruvius sought to address the ethos of architecture, declaring that quality depends on the relevance of the artists work. Perhaps the most famous declaration from De architectura is one still quoted by architects, a modern interpretation of Wottons English might render it thus, The ideal building has three elements, it is sturdy, useful, and beautiful. Vitruvius also studied human proportions and his canones were later encoded in a famous drawing by Leonardo da Vinci. Vitruvius also described the construction of sundials and water clocks, numerous such massive structures occur across the former empire, a testament to the power of Roman engineering. Vitruvius description of Roman aqueduct construction is short, but mentions key details especially for the way they were surveyed, and his book would have been of assistance to Frontinus, a general who was appointed in the late 1st century AD to administer the many aqueducts of Rome. The Roman Empire went far in exploiting water power, as the set of no fewer than 16 water mills at Barbegal in France demonstrates, the mills ground grain in a very efficient operation, and many other mills are now known, such as the much later Hierapolis sawmill. Vitruvius described many different construction materials used for a variety of different structures. Cement, concrete, and lime received in-depth descriptions, the longevity of many Roman structures being mute testimony to their skill in building materials, Vitruvius advised that lead should not be used to conduct drinking water, clay pipes being preferred. He comes to conclusion in Book VIII of De architectura after empirical observation of the apparent laborer illnesses in the plumbum foundries of his time. In 1986, the United States banned the use of lead in plumbing due to lead poisonings neurological damage, however, much of the water used by Rome and many other cities was very hard, and coated the inner surfaces of the pipes, so lead poisoning was unlikely
14.
Pozzuoli
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Pozzuoli is a city and comune of the Metropolitan City of Naples, in the Italian region of Campania. It is the city of the Phlegrean Peninsula. Pozzuoli began as the Greek colony of Dicaearchia, the Roman colony was established in 194 BC, and took the name Puteoli which it has his roots from puteus, meaning well and osco fistulus. An alternative etymology of Puteoli from the Latin puteo, referring to the smell in the area. This is because Pozzuoli lies in the center of the Campi Flegrei, Puteoli was the great emporium for the Alexandrian grain ships, and other ships from all over the Roman world. It also was the hub for goods exported from Campania, including blown glass, mosaics, wrought iron. The Roman naval base at nearby Misenum housed the largest naval fleet in the ancient world and it was also the site of the Roman Dictator Sullas country villa and the place where he died in 78 BC. The local volcanic sand, pozzolana formed the basis for the first effective concrete, instead of just evaporating slowly off, the water would turn this sand/lime mix into a mortar strong enough to bind lumps of aggregate into a load-bearing unit. This made possible the cupola of the Pantheon, which is still the worlds largest unreinforced concrete dome, the apostle Paul landed here on his way to Rome, from which it was 170 miles distant. Here he stayed for seven days and then began with his companions his journey by the Appian Way to Rome, Puteoli is considered the best candidate for the unnamed city where the 1st century Roman novel Satyricon takes place. Saint Proculus was martyred here with his companions in the fourth century, the seven eagle heads on the coat-of-arms for the town of Pozzuoli are said to represent seven of these martyrs. November 16 was the official feast day for Saint Proculus, st. Proculus was affectionately nicknamed u pisciasotto because November 16 was often a day of rain. The townspeople also celebrated his feast day on the second Sunday in May, charles Lyell visited Pozzuoli in 1828 and studied the Macellum columns. The events raised the sea bottom by almost 2 m, the towns attractions include, The Macellum of Pozzuoli, also known as the Temple of Serapis or serapeum, is considered the citys symbol. The temple was actually a marketplace and its name derives from the misinterpretation of its function after a statue of the god Serapis was found in 1750 at this location. Flavian Amphitheater, the third largest Italian amphitheater after the Colosseum, Solfatara Forum Minor Amphitheater, very near to the Flavian one, its remains were absorbed by other buildings, but some arches can be seen by Via Solfatara and Via Vigna. Villa Avellino, one of the few urban parks of Pozzuoli and it also shows several Roman ruins and water tanks. There is also a still working Roman face water fountain, rione Terra, the first settlement of Puteoli, originally Dicearkia in Greek
15.
Great Fire of Rome
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The Great Fire of Rome was an urban fire that started on the night between 18 and 19 July in the year 64 AD. It caused widespread devastation, before being brought under control after six days, differing accounts either blame Emperor Nero for initiating the fire or credit him with organizing measures to contain it and provide relief for refugees. The varying historical accounts of the event come from three secondary sources—Cassius Dio, Suetonius and Tacitus, the primary accounts, which possibly included histories written by Fabius Rusticus, Marcus Cluvius Rufus and Pliny the Elder, did not survive. At least five separate stories circulated regarding Nero and the fire, Motivated by a desire to destroy the city, Nero watched from his palace on the Palatine Hill singing and playing the lyre. Nero quite openly sent out men to set fire to the city, Nero watched from the Tower of Maecenas on the Esquiline Hill singing and playing the lyre. Nero sent out men to set fire to the city, Nero sang and played his lyre from a private stage. The fire was said to have been caused by the already unpopular Christians and this story was spread in order to blame someone else, because rumor had it that Nero started it. Tacitus describes the fire as beginning in shops where flammable goods were stored, in the region of the Circus neighboring the Caelian, the night was a windy one and the flames rapidly spread along the full length of the Circus. The fire expanded through an area of narrow, twisting streets, in this lower area of Rome there were no large buildings such as temples, or open areas of ground, to impede the conflagration. It then spread along the Palatine and Caelian slopes, the population fled first to areas unaffected by the fire and then to the open fields and rural roads outside the city. Looters and arsonists were reported to have spread the flames by throwing torches or, acting in groups, Tacitus surmises that some may have acted under orders or that they may simply have wanted to plunder unhindered. According to Tacitus, Nero was away from Rome, in Antium and he returned to the city and took measures to bring in food supplies and open gardens and public buildings to accommodate refugees. After six days the organized clearing of areas brought the conflagration to a halt before it reached the Esquiline Hill. There was an outbreak in the Aemilian district, involving the destruction of temples and arcades. However the fire was now under control, of Romes 14 districts,3 were completely devastated and only 4 completely escaped damage. Moreover, the destroyed parts of Neros own palace, the Domus Transitoria. It seems unlikely that Nero wanted to destroy this palace since he actually salvaged some of the marble decoration, even the paintings and wall decorations of the new palace were similar to the ones that had been burned. Last, the fire started just two days after a full moon, a time that, it is presumed, would not have been chosen by arsonists who would not have wished to be observed
16.
Nero
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Nero was Roman Emperor from 54 to 68, and the last in the Julio-Claudian dynasty. Nero was adopted by his great-uncle Claudius to become his heir and successor, during his reign, the redoubtable general Corbulo conducted a successful war and negotiated peace with the Parthian Empire. His general Suetonius Paulinus crushed a revolt in Britain, Nero annexed the Bosporan Kingdom to the empire and may have begun the First Jewish–Roman War. In 64 AD, most of Rome was destroyed in the Great Fire of Rome, Suetonius, writing a generation later, claims that many Romans believed Nero himself had started the fire, in order to clear land for his planned palatial complex, the Domus Aurea. In 68, the rebellion of Vindex in Gaul and later the acclamation of Galba in Hispania drove Nero from the throne, facing a false report of being denounced as a public enemy who was to be executed, he committed suicide on 9 June 68. His death ended the Julio-Claudian dynasty, sparking a period of civil wars known as the Year of the Four Emperors. Neros rule is often associated with tyranny and extravagance and he is known for many executions, including that of his mother, and the probable murder by poison of his stepbrother Britannicus. Nero was rumored to have had captured Christians dipped in oil and this view is based on the writings of Tacitus, Suetonius and Cassius Dio, the main surviving sources for Neros reign, but a few sources paint Nero in a more favourable light. Some sources, including some mentioned above, portray him as an emperor who was popular with the common Roman people, some modern historians question the reliability of ancient sources when reporting on Neros tyrannical acts. Lucius Domitius Ahenobarbus, Nero, was born on 15 December 37 in Antium and he was the only son of Gnaeus Domitius Ahenobarbus and Agrippina the Younger, sister of Emperor Caligula. Neros father, Gnaeus, was the son of Lucius Domitius Ahenobarbus, Gnaeus was thus the grandson of Gnaeus Domitius Ahenobarbus and probably Aemilia Lepida on his fathers side, and the grandson of Mark Antony and Octavia Minor on his mothers side. Thus, Nero had as his paternal grandmother Antonia Major, through Octavia, Nero was the great-nephew of Caesar Augustus. Neros father had employed as a praetor and was a member of Caligulas staff when the latter travelled to the East. Neros father was described by Suetonius as a murderer and a cheat who was charged by Emperor Tiberius with treason, adultery, Tiberius died, allowing him to escape these charges. Neros father died of edema in 39 when Nero was two, Neros mother was Agrippina the Younger, a great-granddaughter of Caesar Augustus and his wife Scribonia through their daughter Julia the Elder and her husband Marcus Vipsanius Agrippa. Agrippinas father, Germanicus, was a grandson of Augustuss wife, Livia, on one side and Mark Antony, Germanicus mother Antonia Minor was a daughter of Octavia Minor and Mark Antony. Germanicus was also the son of Tiberius. Agrippina poisoned her second husband Passienus Crispus, so many ancient historians also accuse her of murdering her third husband, the emperor Claudius
17.
Appian Way
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The Appian Way was one of the earliest and strategically most important Roman roads of the ancient republic. It connected Rome to Brindisi, in southeast Italy and its importance is indicated by its common name, recorded by Statius, Appia longarum. The Appian Way was used as a route for military supplies since its construction for that purpose in 312 B. C. The Appian Way was the first long road built specifically to transport troops outside the region of greater Rome. The few roads outside the city were Etruscan and went mainly to Etruria. By the late Republic, the Romans had expanded over most of Italy and were masters of road construction, Rome had an affinity for the people of Campania, who, like themselves, traced their backgrounds to the Etruscans. The Samnite Wars were instigated by the Samnites when Rome attempted to ally itself with the city of Capua in Campania, the Italic speakers in Latium had long ago been subdued and incorporated into the Roman state. They were responsible for changing Rome from a primarily Etruscan to a primarily Italic state, dense populations of sovereign Samnites remained in the mountains north of Capua, which is just north of the Greek city of Neapolis. Around 343 BC, Rome and Capua attempted to form an alliance, the Samnites reacted with military force. Between Capua and Rome lay the Pontine Marshes, a swamp infested with malaria, a tortuous coastal road wound between Ostia at the mouth of the Tiber and Neapolis. The via Latina followed its ancient and scarcely more accessible path along the foothills of Monti Laziali and Monti Lepini, in the First Samnite War the Romans found they could not support or resupply troops in the field against the Samnites across the marsh. A revolt of the Latin League drained their resources further and they gave up the attempted alliance and settled with Samnium. The Romans were only biding their time while they looked for a solution, the first answer was the colonia, a cultivation of settlers from Rome, who would maintain a permanent base of operations. The Second Samnite War erupted when Rome attempted to place a colony at Cales in 334, the Samnites, now a major power after defeating the Greeks of Tarentum, occupied Neapolis to try to ensure its loyalty. The Neapolitans appealed to Rome, which sent an army and expelled the Samnites from Neapolis, in 312 BC, Appius Claudius Caecus became censor at Rome. He was of the gens Claudia, who were descended from the Sabines taken into the early Roman state. He had been given the name of the ancestor of the gens. He was a populist, i. e. an advocate of the common people, a man of inner perspicacity, in the years of success he was said to have lost his outer vision and thus acquired the name caecus, blind
18.
Construction aggregate
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Aggregates are the most mined materials in the world. Aggregates are a component of composite materials such as concrete and asphalt concrete, aggregates are also used as base material under foundations, roads, and railroads. Preferred bitumenous aggregate sizes for road construction are given in EN13043 as d/D, the same classification sizing is used for larger armour stone sizes in EN13383, EN12620 for concrete aggregate, EN13242 for base layers of road construction and EN13450 for railway ballast. These products include specific types of coarse and fine aggregate designed for such uses as additives to asphalt and concrete mixes, state transportation departments further refine aggregate material specifications in order to tailor aggregate use to the needs and available supply in their particular locations. In addition, there are materials that are used as specialty lightweight aggregates, clay, pumice, perlite. People have used sand and stone for foundations for thousands of years, significant refinement of the production and use of aggregate occurred during the Roman Empire, which used aggregate to build its vast network of roads and aqueducts. The invention of concrete, which was essential to architecture utilizing arches, created an immediate, vitruvius writes in De architectura, Economy denotes the proper management of materials and of site, as well as a thrifty balancing of cost and common sense in the construction of works. This will be observed if, in the first place, the architect does not demand things which cannot be found or made ready without great expense, for example, it is not everywhere that there is plenty of pit-sand, rubble, fir, clear fir, and marble. Where there is no pit sand, we must use the kinds washed up by rivers or by the sea. the advent of modern blasting methods enabled the development of quarries, which are now used throughout the world, wherever competent bedrock deposits of aggregate quality exist. In many places, good limestone, granite, marble or other quality stone bedrock deposits do not exist, in these areas, natural sand and gravel are mined for use as aggregate. Where neither stone, nor sand and gravel, are available, construction demand is satisfied by shipping in aggregate by rail. Additionally, demand for aggregates can be satisfied through the use of slag. However, the available tonnages and lesser quality of these materials prevent them from being a replacement for mined aggregates on a large scale. Large stone quarry and sand and gravel operations exist near virtually all population centers, limestone and granite are also produced in large amounts as dimension stone. The great majority of crushed stone is moved by truck from the quarry/plant to the first point of sale or use. According to the USGS,2006 U. S. sand and gravel production was 1.32 billion tonnes valued at $8.54 billion, the great majority of this was again moved by truck, instead of by electric train. Currently, total U. S. aggregate demand by final market sector was 30%–35% for non-residential building, 25% for highways, the largest-volume of recycled material used as construction aggregate is blast furnace and steel furnace slag. Blast furnace slag is either air-cooled or granulated, if the granulated blast furnace slag accesses free lime during hydration, it develops strong hydraulic cementitious properties and can partly substitute for portland cement in concrete
19.
Mortar (masonry)
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In its broadest sense mortar includes pitch, asphalt, and soft mud or clay, such as used between mud bricks. Mortar comes from Latin mortarium meaning crushed, mortars are typically made from a mixture of sand, a binder, and water. The most common binder since the early 20th century is Portland cement, there are several types of cement mortars and additives. The first mortars were made of mud and clay, because of a lack of stone and an abundance of clay, Babylonian constructions were of baked brick, using lime or pitch for mortar. According to Roman Ghirshman, the first evidence of using a form of mortar was at the Mehrgarh of Baluchistan in Pakistan. The ancient sites of Harappan civilization of third millennium BCE are built with kiln-fired bricks, gypsum mortar, also called plaster of Paris, was used in the construction of the Egyptian pyramids and many other ancient structures. It is made from gypsum, which requires a firing temperature. It is therefore easier to make lime mortar and sets up much faster which may be a reason it was used as the typical mortar in ancient, brick arch. Gypsum mortar is not as durable as other mortars in damp conditions, in early Egyptian pyramids, which were constructed during the Old Kingdom, the limestone blocks were bound by mortar of mud and clay, or clay and sand. In later Egyptian pyramids, the mortar was made of gypsum or lime. Gypsum mortar was essentially a mixture of plaster and sand and was quite soft, in the Indian subcontinent, multiple cement types have been observed in the sites of the Indus Valley Civilization, such as the Mohenjo-daro city-settlement that dates to earlier than 2600 BCE. Bitumen mortar was used at a lower-frequency, including in the Great Bath at Mohenjo-daro. Historically, building with concrete and mortar next appeared in Greece, the excavation of the underground aqueduct of Megara revealed that a reservoir was coated with a pozzolanic mortar 12 mm thick. This aqueduct dates back to c.500 BCE, pozzolanic mortar is a lime based mortar, but is made with an additive of volcanic ash that allows it to be hardened underwater, thus it is known as hydraulic cement. The Greeks obtained the volcanic ash from the Greek islands Thira and Nisiros, or from the then Greek colony of Dicaearchia near Naples, the Romans later improved the use and methods of making what became known as pozzolanic mortar and cement. Even later, the Romans used a mortar without pozzolana using crushed terra cotta, introducing aluminum oxide and this mortar was not as strong as pozzolanic mortar, but, because it was denser, it better resisted penetration by water. Hydraulic mortar was not available in ancient China, possibly due to a lack of volcanic ash, around 500 CE, sticky rice soup was mixed with slaked lime to make an inorganic−organic composite mortar that had more strength and water resistance than lime mortar. It is not understood how the art of making hydraulic mortar and cement, during the Middle Ages when the Gothic cathedrals were being built, the only active ingredient in the mortar was lime
20.
Ceramic
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A ceramic is an inorganic, non-metallic, solid material comprising metal, non-metal or metalloid atoms primarily held in ionic and covalent bonds. This article gives an overview of ceramic materials from the point of view of materials science, the crystallinity of ceramic materials ranges from highly oriented to semi-crystalline, vitrified, and often completely amorphous. Most often, fired ceramics are either vitrified or semi-vitrified as is the case with earthenware, stoneware, varying crystallinity and electron consumption in the ionic and covalent bonds cause most ceramic materials to be good thermal and electrical insulators. With such a range of possible options for the composition/structure of a ceramic, the breadth of the subject is vast. Many composites, such as fiberglass and carbon fiber, while containing ceramic materials, are not considered to be part of the ceramic family. The earliest ceramics made by humans were pottery objects or figurines made from clay, either by itself or mixed with materials like silica, hardened, sintered. Later ceramics were glazed and fired to create smooth, colored surfaces, decreasing porosity through the use of glassy, ceramics now include domestic, industrial and building products, as well as a wide range of ceramic art. In the 20th century, new materials were developed for use in advanced ceramic engineering. The word ceramic comes from the Greek word κεραμικός, of pottery or for pottery, from κέραμος, potters clay, tile, the earliest known mention of the root ceram- is the Mycenaean Greek ke-ra-me-we, workers of ceramics, written in Linear B syllabic script. The word ceramic may be used as an adjective to describe a material, product or process, or it may be used as a noun, either singular, or, more commonly, as the plural noun ceramics. A ceramic material is an inorganic, non-metallic, often crystalline oxide, nitride or carbide material, some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, weak in shearing and they withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand high temperatures, such as temperatures that range from 1,000 °C to 1,600 °C. Glass is often not considered a ceramic because of its amorphous character. However, glassmaking involves several steps of the process and its mechanical properties are similar to ceramic materials. Traditional ceramic raw materials include minerals such as kaolinite, whereas more recent materials include aluminium oxide. The modern ceramic materials, which are classified as advanced ceramics, include silicon carbide, both are valued for their abrasion resistance, and hence find use in applications such as the wear plates of crushing equipment in mining operations. Advanced ceramics are used in the medicine, electrical, electronics industries. Crystalline ceramic materials are not amenable to a range of processing
21.
Gypsum
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Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is widely mined and is used as a fertilizer, and as the constituent in many forms of plaster, blackboard chalk. Mohs scale of hardness, based on scratch Hardness comparison. It forms as a mineral and as a hydration product of anhydrite. The word gypsum is derived from the Greek word γύψος, plaster, because the quarries of the Montmartre district of Paris have long furnished burnt gypsum used for various purposes, this dehydrated gypsum became known as plaster of Paris. Upon addition of water, after a few tens of minutes plaster of Paris becomes regular gypsum again, causing the material to harden or set in ways that are useful for casting, Gypsum was known in Old English as spærstān, spear stone, referring to its crystalline projections. Gypsum may act as a source of sulfur for plant growth, which was discovered by J. M. Mayer, american farmers were so anxious to acquire it that a lively smuggling trade with Nova Scotia evolved, resulting in the so-called Plaster War of 1820. In the 19th century, it was known as lime sulfate or sulfate of lime. Gypsum is moderately water-soluble and, in contrast to most other salts, it exhibits retrograde solubility, when gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate, and, if heated further, to anhydrous calcium sulfate. As for anhydrite, its solubility in saline solutions and in brines is also dependent on NaCl concentration. Gypsum crystals are found to contain water and hydrogen bonding. Gypsum occurs in nature as flattened and often twinned crystals, and transparent, selenite contains no significant selenium, rather, both substances were named for the ancient Greek word for the Moon. Selenite may also occur in a silky, fibrous form, in case it is commonly called satin spar. Finally, it may also be granular or quite compact, in hand-sized samples, it can be anywhere from transparent to opaque. A very fine-grained white or lightly tinted variety of gypsum, called alabaster, is prized for ornamental work of various sorts, in arid areas, gypsum can occur in a flower-like form, typically opaque, with embedded sand grains called desert rose. It also forms some of the largest crystals found in nature, up to 12 m long, Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as far back as the Archaean eon, Gypsum is deposited from lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins. Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in near-surface exposures and it is often associated with the minerals halite and sulfur
22.
Calcium oxide
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Calcium oxide, commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, caustic, alkaline, crystalline solid at room temperature, the broadly used term lime connotes calcium-containing inorganic materials, in which carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. By contrast, quicklime specifically applies to the chemical compound calcium oxide. Calcium oxide that survives processing without reacting in building such as cement is called free lime. Both it and a chemical derivative are important commodity chemicals, Calcium oxide is usually made by the thermal decomposition of materials, such as limestone or seashells, that contain calcium carbonate in a lime kiln. This is accomplished by heating the material to above 825 °C, annual worldwide production of quicklime is around 283 million tonnes. China is by far the worlds largest producer, with a total of around 170 million tonnes per year, the United States is the next largest, with around 20 million tonnes per year. Approximately 1.8 t of limestone is required per 1.0 t of quicklime, quicklime has a high affinity for water and is a more efficient desiccant than silica gel. The reaction of quicklime with water is associated with an increase in volume by a factor of at least 2.5, the major use of quicklime is in the Basic oxygen steelmaking process. Its usage varies from about 30–50 kg/t of steel, the quicklime neutralizes the acidic oxides, SiO2, Al2O3, and Fe2O3, to produce a basic molten slag. Ground quicklime is used in the production of aerated concrete blocks, quicklime and hydrated lime can considerably increase the load carrying capacity of clay-containing soils. They do this by reacting with finely divided silica and alumina to produce calcium silicates and aluminates, small quantities of quicklime are used in other processes, e. g. the production of glass, calcium aluminate cement, and organic chemicals. The hydrate can be reconverted to quicklime by removing the water by heating it to redness to reverse the hydration reaction, one litre of water combines with approximately 3.1 kilograms of quicklime to give calcium hydroxide plus 3.54 MJ of energy. This process can be used to provide a convenient portable source of heat, light, When quicklime is heated to 2,400 °C, it emits an intense glow. This form of illumination is known as a limelight, and was used broadly in theatrical productions prior to the invention of electric lighting, cement, Calcium oxide is a key ingredient for the process of making cement. As a cheap and widely available alkali, about 50% of the total quicklime production is converted to calcium hydroxide before use. Both quick- and hydrated lime are used in the treatment of drinking water, petroleum industry, Water detection pastes contain a mix of calcium oxide and phenolphthalein. Should this paste come into contact with water in a storage tank
23.
Aluminium oxide
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Aluminium oxide or aluminum oxide is a chemical compound of aluminium and oxygen with the chemical formula Al2O3. It is the most commonly occurring of several aluminium oxides, and it is commonly called alumina, and may also be called aloxide, aloxite, or alundum depending on particular forms or applications. It occurs naturally in its crystalline polymorphic phase α-Al2O3 as the mineral corundum, varieties of form the precious gemstones ruby. Al2O3 is significant in its use to produce metal, as an abrasive owing to its hardness. Corundum is the most common naturally occurring form of aluminium oxide. Rubies and sapphires are gem-quality forms of corundum, which owe their characteristic colors to trace impurities, rubies are given their characteristic deep red color and their laser qualities by traces of chromium. Sapphires come in different colors given by various other impurities, such as iron, Al2O3 is an electrical insulator but has a relatively high thermal conductivity for a ceramic material. Aluminium oxide is insoluble in water, in its most commonly occurring crystalline form, called corundum or α-aluminium oxide, its hardness makes it suitable for use as an abrasive and as a component in cutting tools. Aluminium oxide is responsible for the resistance of aluminium to weathering. Metallic aluminium is very reactive with oxygen, and a thin passivation layer of aluminium oxide forms on any exposed aluminium surface. This layer protects the metal from further oxidation, the thickness and properties of this oxide layer can be enhanced using a process called anodising. A number of alloys, such as bronzes, exploit this property by including a proportion of aluminium in the alloy to enhance corrosion resistance. Aluminium oxide was taken off the United States Environmental Protection Agencys chemicals lists in 1988, aluminium oxide is on EPAs Toxics Release Inventory list if it is a fibrous form. Al2O3 +6 HF →2 AlF3 +3 H2O Al2O3 +2 NaOH +3 H2O →2 NaAl4 The most common form of aluminium oxide is known as corundum. The oxygen ions form a hexagonal close-packed structure with aluminium ions filling two-thirds of the octahedral interstices. In terms of its crystallography, corundum adopts a trigonal Bravais lattice with a group of R-3c. The primitive cell contains two units of aluminium oxide. Each has a crystal structure and properties
24.
Tuff
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Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is compacted into a rock in a process called consolidation. Tuff is sometimes called tufa, particularly used as construction material. Rock that contains greater than 50% tuff is considered tuffaceous, Tuff is a relatively soft rock, so it has been used for construction since ancient times. Since it is common in Italy the Romans used it often for construction, the Rapa Nui people used it to make most of the moai statues in Easter Island. Tuff can be classified as either sedimentary or igneous rocks and they are usually studied in the context of igneous petrology, although they are sometimes described using sedimentological terms. The material that is expelled in a volcanic eruption can be classified into three types, Volcanic gases, a mixture mostly of water vapour, carbon dioxide. Lava, the name of magma when it emerges and flows over the surface, and tephra, chunks of solid material of all shapes and sizes ejected and thrown through the air. Tephra is made when magma inside the volcano is blown apart by the expansion of hot volcanic gases. It is common for magma to explode as the gas dissolved in it comes out of solution as the pressure decreases when it flows to the surface and these violent explosions produce solid chunks of material that can then fly from the volcano. When these chunks are smaller than 2 mm in diameter they are called volcanic ash and it is made of small, slaggy pieces of lava and rock that have been tossed into the air by outbursts of steam and other gases. Among the loose beds of ash that cover the slopes of many volcanoes, in addition to true ashes of the kind described above, there are lumps of the old lavas and tuffs forming the walls of the crater, etc. In some great volcanic explosions nothing but materials of the kind were emitted. The ashes vary in size from large blocks twenty feet or more in diameter to the minutest impalpable dust, the large masses are called volcanic bombs, they have mostly a rounded, elliptical or pear-shaped form owing to rotation in the air before they solidified. Many of them have ribbed or nodular surfaces, and sometimes they have a crust intersected by many cracks like the surface of a loaf of bread, any ash in which they are very abundant is called an agglomerate. But many volcanoes stand near the sea, and the ashes cast out by them are mingled with the sediments that are gathering at the bottom of the waters, in this way ashy muds or sands or even in some cases ashy limestones are being formed. As a matter of fact most of the found in the older formations contain admixtures of clay, sand, and sometimes fossil shells. The showers of ashes often follow one another after longer or shorter intervals, the coarsest materials or agglomerates show this least distinctly, in the fine beds it is often developed in great perfection
25.
Rheology
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The term rheology was coined by Eugene C. Bingham, a professor at Lafayette College, in 1920, from a suggestion by a colleague, the term was inspired by the aphorism of Simplicius, panta rhei, everything flows, and was first used to describe the flow of liquids and the deformation of solids. Newtonian fluids can be characterized by a coefficient of viscosity for a specific temperature. Although this viscosity will change with temperature, it does not change with the strain rate, only a small group of fluids exhibit such constant viscosity. The large class of fluids whose viscosity changes with the rate are called non-Newtonian fluids. For example, ketchup can have its viscosity reduced by shaking, ketchup is a shear thinning material, like yogurt and emulsion paint, exhibiting thixotropy, where an increase in relative flow velocity will cause a reduction in viscosity, for example, by stirring. Some other non-Newtonian materials show the behavior, rheopecty, viscosity going up with relative deformation. Since Sir Isaac Newton originated the concept of viscosity, the study of liquids with strain rate dependent viscosity is also often called Non-Newtonian fluid mechanics, materials with the characteristics of a fluid will flow when subjected to a stress which is defined as the force per area. There are different sorts of stress and materials can respond differently for different stresses, much of theoretical rheology is concerned with associating external forces and torques with internal stresses and internal strain gradients and flow velocities. In this sense, a solid undergoing plastic deformation is a fluid, granular rheology refers to the continuum mechanical description of granular materials. These experimental techniques are known as rheometry and are concerned with the determination with well-defined rheological material functions, such relationships are then amenable to mathematical treatment by the established methods of continuum mechanics. The characterization of flow or deformation originating from a shear stress field is called shear rheometry. The study of extensional flows is called extensional rheology, shear flows are much easier to study and thus much more experimental data are available for shear flows than for extensional flows. A rheologist is an interdisciplinary scientist or engineer who studies the flow of liquids or the deformation of soft solids. It is not a degree subject, there is no qualification of rheologist as such. Most rheologists have a qualification in mathematics, the sciences, engineering, medicine, or certain technologies. Elasticity is essentially a time independent processes, as the strains appear the moment the stress is applied, if the material deformation rate increases linearly with increasing applied stress, then the material is viscous in the Newtonian sense. These materials are characterized due to the delay between the applied constant stress and the maximum strain
26.
Geopolymer
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Geopolymers are inorganic, typically ceramic, materials that form long-range, covalently bonded, non-crystalline networks. Obsidian is an example of naturally occurring geopolymer, raw materials used in the synthesis of silicon-based polymers are mainly rock-forming minerals of geological origin, hence the name, geopolymer. Joseph Davidovits coined the term in 1978 and created the non profit French scientific institution Institut Géopolymère, yen geopolymers can be classified into two major groups, pure inorganic geopolymers and organic containing geopolymers, synthetic analogues of naturally occurring macromolecules. This mineral synthesis was first presented at an IUPAC symposium in 1976, the microstructure of geopolymers is essentially temperature dependent, It is X-ray amorphous at room temperature, But evolves into a crystalline matrix at temperatures above 500 °C. One can distinguish between two routes, In alkaline medium, In acidic medium with phosphoric acid and humic acids. The alkaline route is the most important in terms of R&D and commercial applications, the examples below were taken from 2011 scientific publications, written by scientists with different backgrounds. Definitions of the term geopolymer For chemists. Geopolymers consist of a polymeric Si–O–Al framework, the main difference to zeolite is geopolymers are amorphous instead of crystalline. The microstructure of geopolymers on a nanometer scale observed by TEM comprises small aluminosilicate clusters with pores dispersed within a highly porous network, the clusters sizes are between 5 and 10 nanometers. For geopolymer material chemists. The reaction produces SiO4 and AlO4, the connection of the tetrahedral frameworks is occurred via long-range covalent bonds. Thus, geopolymer structure is perceived as dense amorphous phase consisting of semi-crystalline 3-D alumino-silicate microstructure, Geopolymers are framework structures produced by condensation of tetrahedral aluminosilicate units, with alkali metal ions balancing the charge associated with tetrahedral Al. Conventionally, geopolymers are synthesized from a mix, consisting of an alkaline solution. For ceramic scientists. Geopolymers are a class of totally inorganic, the fundamental unit within a geopolymer structure is a tetrahedral complex consisting of Si or Al coordinated through covalent bonds to four oxygens. These alkali metal cations are often ion-exchangeable, as they are associated with, but only loosely bonded to, geopolymerization is the process of combining many small molecules known as oligomers into a covalently bonded network. At room temperature or higher, the reaction is so fast that it cannot be detected with conventional analytical equipment, the image shows 5 soluble oligomers of the K-poly / poly species, which are the actual starting units of potassium-based alumino-silicate geopolymerization. The geopolymerization kinetics for Na-poly and K-poly are slightly different respectively and this is probably due to the different dimensions of the Na+ and K+ cations, K+ being bigger than Na+. These monomers inter-react to form dimers, which in turn react with other monomers to form trimers, tetramers, when the solution reaches saturation, an aluminum-rich gel precipitates. Geopolymerization forms aluminosilicate frameworks that are similar to those of rock-forming minerals, in 1994, Davidovits presented a theoretical structure for K-poly - that was consistent with the NMR spectra. It does not show the presence of water in the structure because he focused on the relationship between Si, Al, Na, K, atoms
27.
Slag
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Slag is the glass-like by-product left over after a desired metal has been separated from its raw ore. Slag is usually a mixture of oxides and silicon dioxide. However, slags can contain metal sulfides and elemental metals, in nature, iron, copper, lead, nickel and other metals are found in impure states called ores, often oxidized and mixed in with silicates of other metals. During smelting, when the ore is exposed to high temperatures, Slag is the collection of compounds that are removed. In many smelting processes, oxides are introduced to control the slag chemistry, assisting in the removal of impurities, in this case, the slag is termed synthetic. Ferrous and non-ferrous smelting processes produce different slags, the smelting of copper and lead in non-ferrous smelting, for instance, is designed to remove the iron and silica that often occurs with those ores, and separates them as iron-silicate-based slags. Slag from steel mills in ferrous smelting, on the hand, is designed to minimize iron loss and so mainly contains oxides of calcium, silicon, magnesium. Any sandy component or quartz component of the original ore automatically carries through the process as silicon dioxide. As the slag is channeled out of the furnace, water is poured over it and this rapid cooling, often from a temperature of around 2,600 °F, is the start of the granulating process. This process causes several chemical reactions to take place within the slag, the water carries the slag in its slurry format to a large agitation tank, from where it is pumped along a piping system into a number of gravel based filter beds. The filter beds then retain the slag granules, while the drains away and is returned to the system. During the Bronze Age of the Mediterranean there were a vast number of metallurgical processes in use. A slag by-product of such workings was a colorful, glassy and it was primarily blue or green and was formerly chipped away and melted down to make glassware products and jewelry. It was also ground into powder to add to glazes for use in ceramics, some of the earliest such uses for the by-products of slag have been found in ancient Egypt. Historically, the re-smelting of iron ore slag was common practice, during the early 20th century, iron ore slag was also ground to a powder and used to make agate glass, also known as slag glass. Ground granulated slag is used in concrete in combination with Portland cement as part of a blended cement. Ground granulated slag reacts with water to produce cementitious properties, concrete containing ground granulated slag develops strength over a longer period, leading to reduced permeability and better durability. Since the unit volume of Portland cement is reduced, this concrete is less vulnerable to alkali-silica, the slag can also be used to create fibers used as an insulation material called slag wool
28.
Fly ash
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Fly ash, also known as pulverised fuel ash in the United Kingdom, is one of the coal combustion products, composed of the fine particles that are driven out of the boiler with the flue gases. Ash that falls in the bottom of the boiler is called bottom ash, in modern coal-fired power plants, fly ash is generally captured by electrostatic precipitators or other particle filtration equipment before the flue gases reach the chimneys. Together with bottom ash removed from the bottom of the boiler, in the past, fly ash was generally released into the atmosphere, but air pollution control standards now require that it be captured prior to release by fitting pollution control equipment. In the US, fly ash is stored at coal power plants or placed in landfills. About 43% is recycled, often used as a pozzolan to produce hydraulic cement or hydraulic plaster, pozzolans ensure the setting of concrete and plaster and provide concrete with more protection from wet conditions and chemical attack. Coal Combustion Residuals are listed in the subtitle D, in that case the ash produced is often classified as hazardous waste. Fly ash material solidifies while suspended in the exhaust gases and is collected by electrostatic precipitators or filter bags. Since the particles solidify rapidly while suspended in the exhaust gases, fly ash particles are spherical in shape. The major consequence of the cooling is that few minerals have time to crystallize. Nevertheless, some refractory phases in the coal do not melt. In consequence, fly ash is a heterogeneous material, siO2, Al2O3, Fe2O3 and occasionally CaO are the main chemical components present in fly ashes. The mineralogy of fly ashes is very diverse, the main phases encountered are a glass phase, together with quartz, mullite and the iron oxides hematite, magnetite and/or maghemite. Other phases often identified are cristobalite, anhydrite, free lime, periclase, calcite, sylvite, halite, portlandite, rutile and anatase. The Ca-bearing minerals anorthite, gehlenite, akermanite and various calcium silicates, the mercury content can reach 1 ppm, but is generally included in the range 0.01 -1 ppm for bituminous coal. The concentrations of trace elements vary as well according to the kind of coal combusted to form it. In fact, in the case of coal, with the notable exception of boron. Two classes of fly ash are defined by ASTM C618, Class F fly ash, the chief difference between these classes is the amount of calcium, silica, alumina, and iron content in the ash. The chemical properties of the fly ash are largely influenced by the content of the coal burned
29.
Silica fume
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Silica fume, also known as microsilica, is an amorphous polymorph of silicon dioxide, silica. It is an ultrafine powder collected as a by-product of the silicon and ferrosilicon alloy production, the main field of application is as pozzolanic material for high performance concrete. It is sometimes confused with fumed silica, however, the production process, particle characteristics and fields of application of fumed silica are all different from those of silica fume. The first testing of silica fume in Portland-cement-based concretes was carried out in 1952, the biggest drawback to exploring the properties of silica fume was a lack of material with which to experiment. Early research used an expensive additive called fumed silica, a form of silica made by combustion of silicon tetrachloride in a hydrogen-oxygen flame. Silica fume on the hand, is a very fine pozzolanic, amorphous material. Before the late 1960s in Europe and the mid-1970s in the United States, with the implementation of tougher environmental laws during the mid-1970s, silicon smelters began to collect the silica fume and search for its applications. The early work done in Norway received most of the attention, since it had shown that Portland cement-based-concretes containing silica fumes had very high strengths and low porosities. Since then the research and development of silica made it one of the world’s most valuable and versatile admixtures for concrete. Silica fume is a material with spherical particles less than 1 μm in diameter. This makes it approximately 100 times smaller than the average cement particle, the bulk density of silica fume depends on the degree of densification in the silo and varies from 130 to 600 kg/m3. The specific gravity of silica fume is generally in the range of 2.2 to 2.3, the specific surface area of silica fume can be measured with the BET method or nitrogen adsorption method. It typically ranges from 15,000 to 30,000 m2/kg, because of its extreme fineness and high silica content, silica fume is a very effective pozzolanic material. Standard specifications for silica fume used in cementitious mixtures are ASTM C1240, Silica fume is added to Portland cement concrete to improve its properties, in particular its compressive strength, bond strength, and abrasion resistance. Prior to the mid-1970s, nearly all silica fume was discharged into the atmosphere, although the slump decreases, the mix remains highly cohesive. Silica fume also blocks the pores in the fresh concrete so water within the concrete is not allowed to come to the surface, engineered cementitious composite Energetically modified cement Fly ash Kaolinite Pozzolan Rice husk ash Metakaolin U. S. Federal Highway Administration. Chapter 3 Fly Ash, Slag, Silica Fume, and Natural Pozzolans
30.
Seawater
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Seawater, or salt water, is water from a sea or ocean. On average, seawater in the oceans has a salinity of about 3. 5% This means that every kilogram of seawater has approximately 35 grams of dissolved salts. Average density at the surface is 1.025 kg/l, seawater is denser than both fresh water and pure water because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases, at typical salinity, it freezes at about −2 °C. The coldest seawater ever recorded was in 2010, in a stream under an Antarctic glacier, seawater pH is typically limited to a range between 7.5 and 8.4. However, there is no universally accepted reference pH-scale for seawater, although the vast majority of seawater has a salinity of between 31 g/kg and 38 g/kg, seawater is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths, near melting glaciers or vast amounts precipitation, the most saline open sea is the Red Sea, where high rates of evaporation, low precipitation and low river run-off, and confined circulation result in unusually salty water. The salinity in isolated bodies of water can be considerably greater still, historically, several salinity scales were used to approximate the absolute salinity of seawater. A popular scale was the Practical Salinity Scale where salinity was measured in practical salinity units, the current standard for salinity is the Reference Salinity scale with the salinity expressed in units of g/kg. The density of surface seawater ranges from about 1020 to 1029 kg/m3, depending on the temperature, at a temperature of 25 °C, salinity of 35 g/kg and 1 atm pressure, the density of seawater is 1023.6 kg/m3. Deep in the ocean, under pressure, seawater can reach a density of 1050 kg/m3 or higher. The density of seawater also changes with salinity, brines generated by seawater desalination plants can have salinities up to 120 g/kg. The density of typical seawater brine of 120 g/kg salinity at 25 °C, seawater pH is limited to the range 7.5 to 8.4. The speed of sound in seawater is about 1,500 m/s, and varies with temperature, salinity. The thermal conductivity of seawater is 0.6 W/mK at 25 °C, the thermal conductivity decreases with increasing salinity and increases with increasing temperature. Seawater contains more dissolved ions than all types of freshwater, however, the ratios of solutes differ dramatically. Bicarbonate ions also constitute 48% of river water solutes but only 0. 14% of all seawater ions, differences like these are due to the varying residence times of seawater solutes, sodium and chlorine have very long residence times, while calcium tends to precipitate much more quickly. The most abundant dissolved ions in seawater are sodium, chloride, magnesium, sulfate and its osmolarity is about 1000 mOsm/l
31.
Tobermorite
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Not to be confused with torbernite, a hydrated copper uranyl phosphate. Tobermorite is a calcium silicate hydrate mineral with formula, Ca5Si6O162·4H2O or Ca5Si618·5H2O. Two structural varieties are distinguished, tobermorite-11 Å and tobermorite-14 Å, Tobermorite occurs in hydrated cement paste and can be found in nature as alteration mineral in metamorphosed limestone and in skarn. It has been reported from the Maqarin Area of north Jordan and in the Crestmore Quarry near Crestmore Heights, Riverside County, Tobermorite was first described in 1880 for an occurrence in Scotland, on the Isle of Mull, around the locality of Tobermory. Aluminium substituted tobermorite is understood to be a key ingredient in the longevity of ancient undersea Roman concrete, other Calcium silicate hydrate minerals, Afwillite Jennite Thaumasite Tobermorite in the American Mineralogist Crystal Structure Database
32.
Phillipsite
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Phillipsite is a mineral series of the zeolite group, a hydrated potassium, calcium and aluminium silicate, approximating to 3Al6Si10O32·12H2O. The members of the series are phillipsite-K, phillipsite-Na and phillipsite-Ca, the crystals are monoclinic, but only complex cruciform twins are known, these being exactly like twins of harmotome which also forms a series with phillipsite-Ca. Crystals of phillipsite are, however, usually smaller and more transparent, spherical groups with a radially fibrous structure and bristled with crystals on the surface are not uncommon. The Mohs hardness is 4.5, and the gravity is 2.2. The species was established by Armand Lévy in 1825 and named after William Phillips, french authors use the name Christianite, given by A. Small crystals of recent formation have been observed in the masonry of the hot baths at Plombires and Bourbonne-les-Bains, minute spherical aggregates embedded in pelagic red clay were dredged by the Challenger from deep sea sedimenary deposits in the Pacific Ocean. List of minerals List of minerals named after people Leonard James Spencer
33.
Aluminium
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Aluminium or aluminum is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal, Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is combined in over 270 different minerals. The chief ore of aluminium is bauxite, Aluminium is remarkable for the metals low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the industry and important in transportation and structures, such as building facades. The oxides and sulfates are the most useful compounds of aluminium, despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals. Because of these salts abundance, the potential for a role for them is of continuing interest. Aluminium is a soft, durable, lightweight, ductile. It is nonmagnetic and does not easily ignite, a fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation. The yield strength of aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel and it is easily machined, cast, drawn and extruded. Aluminium atoms are arranged in a cubic structure. Aluminium has an energy of approximately 200 mJ/m2. Aluminium is a thermal and electrical conductor, having 59% the conductivity of copper. Aluminium is capable of superconductivity, with a critical temperature of 1.2 kelvin. Aluminium is the most common material for the fabrication of superconducting qubits, the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts, particularly in the presence of dissimilar metals. In highly acidic solutions, aluminium reacts with water to form hydrogen, primarily because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium
34.
Earthquake
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An earthquake is the shaking of the surface of the Earth, resulting from the sudden release of energy in the Earths lithosphere that creates seismic waves. Earthquakes can range in size from those that are so weak that they cannot be felt to those violent enough to people around. The seismicity or seismic activity of an area refers to the frequency, type, Earthquakes are measured using measurements from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe and these two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly imperceptible or weak and magnitude 7 and over potentially cause damage over larger areas. The largest earthquakes in historic times have been of magnitude slightly over 9, intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the damage to structures it causes. At the Earths surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground, when the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity, in its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of faults, but also by other events such as volcanic activity, landslides, mine blasts. An earthquakes point of rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter, tectonic earthquakes occur anywhere in the earth where there is sufficient stored elastic strain energy to drive fracture propagation along a fault plane. The sides of a fault move past each other smoothly and aseismically only if there are no irregularities or asperities along the surface that increase the frictional resistance. Most fault surfaces do have such asperities and this leads to a form of stick-slip behavior, once the fault has locked, continued relative motion between the plates leads to increasing stress and therefore, stored strain energy in the volume around the fault surface. This continues until the stress has risen sufficiently to break through the asperity, suddenly allowing sliding over the portion of the fault. This energy is released as a combination of radiated elastic strain seismic waves, frictional heating of the fault surface and this process of gradual build-up of strain and stress punctuated by occasional sudden earthquake failure is referred to as the elastic-rebound theory. It is estimated that only 10 percent or less of a total energy is radiated as seismic energy. Most of the energy is used to power the earthquake fracture growth or is converted into heat generated by friction
35.
Italian Peninsula
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The Italian Peninsula or Apennine Peninsula is the central and the smallest of the three large peninsulas of Southern Europe. It extends 1,000 km from the Po Valley in the north to the central Mediterranean Sea in the south, the peninsulas shape gives it the nickname lo Stivale. Three smaller peninsulas contribute to this shape, namely Calabria, Salento. Geographically, the Italian peninsula consists of the south of a line extending from the Magra to the Rubicon rivers. It excludes the Po Valley and the slopes of the Alps. All of the lies within the territory of the Italian Republic except for the microstates of San Marino. Additionally, Sicily, Elba and other islands, such as Palagruža, are usually considered as islands off the peninsula. The peninsula lies between the Tyrrhenian Sea on the west, the Ionian Sea on the south, and the Adriatic Sea on the east, the backbone of the Italian peninsula consists of the Apennine Mountains, from which it takes one of its names. Most of its coast is lined with cliffs, the Italian Peninsulas location between the centre of Europe and the Mediterranean Sea made it the target of many conquests. The peninsula has mainly a Mediterranean climate, though in the parts the climate is much cooler. Its natural vegetation includes macchia along the coasts and deciduous and mixed coniferous forests in the interior. Political divisions of the peninsula sorted by area, Apennine Mountains Roman Republic Roman Italy Insular Italy Media related to Italian Peninsula at Wikimedia Commons
36.
Strength of materials
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Strength of materials, also called mechanics of materials, is a subject which deals with the behavior of solid objects subject to stresses and strains. An important founding pioneer in mechanics of materials was Stephen Timoshenko, the study of strength of materials often refers to various methods of calculating the stresses and strains in structural members, such as beams, columns, and shafts. In materials science, the strength of a material is its ability to withstand a load without failure or plastic deformation. The field of strength of materials deals with forces and deformations that result from their acting on a material, a load applied to a mechanical member will induce internal forces within the member called stresses when those forces are expressed on a unit basis. The stresses acting on the material cause deformation of the material in various manners, deformation of the material is called strain when those deformations too are placed on a unit basis. The applied loads may be axial, or rotational, the stresses and strains that develop within a mechanical member must be calculated in order to assess the load capacity of that member. This requires a description of the geometry of the member, its constraints, the loads applied to the member. With a complete description of the loading and the geometry of the member, once the state of stress and strain within the member is known, the strength of that member, its deformations, and its stability can be calculated. The calculated stresses may then be compared to some measure of the strength of the such as its material yield or ultimate strength. The calculated deflection of the member may be compared to a deflection criteria that is based on the members use, the calculated buckling load of the member may be compared to the applied load. The calculated stiffness and mass distribution of the member may be used to calculate the dynamic response. The ultimate strength refers to the point on the engineering stress–strain curve corresponding to the stress that produces fracture, transverse loading - Forces applied perpendicular to the longitudinal axis of a member. Transverse loading causes the member to bend and deflect from its position, with internal tensile. Transverse loading also induces shear forces that cause shear deformation of the material, axial loading - The applied forces are collinear with the longitudinal axis of the member. The forces cause the member to either stretch or shorten, uniaxial stress is expressed by σ = F A where F is the force acting on an area A. The area can be the area or the deformed area. A simple case of compression is the uniaxial compression induced by the action of opposite, compressive strength for materials is generally higher than their tensile strength. However, structures loaded in compression are subject to additional failure modes, such as buckling, that are dependent on the members geometry
37.
Pumice
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Pumice, called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals. Scoria is another vesicular volcanic rock that differs from pumice in having larger vesicles, thicker walls and being dark colored. Pumice is created when super-heated, highly pressurized rock is violently ejected from a volcano, the unusual foamy configuration of pumice happens because of simultaneous rapid cooling and rapid depressurization. The depressurization creates bubbles by lowering the solubility of gases that are dissolved in the lava, the simultaneous cooling and depressurization freezes the bubbles in a matrix. Eruptions under water are cooled and the large volume of pumice created can be a shipping hazard for cargo ships. Pumice is composed of highly microvesicular glass pyroclastic with very thin and it is commonly, but not exclusively of silicic or felsic to intermediate in composition, but basaltic and other compositions are known. Pumice is commonly pale in color, ranging from white, cream, blue or grey and it forms when volcanic gases exsolving from viscous magma form bubbles that remain within the viscous magma as it cools to glass. Pumice is a product of explosive eruptions and commonly forms zones in upper parts of silicic lavas. Pumice has a porosity of 90%, and initially floats on water. Scoria differs from pumice in being denser, with larger vesicles and thicker vesicle walls, it sinks rapidly. The difference is the result of the viscosity of the magma that forms scoria. When larger amounts of gas are present, the result is a variety of pumice known as pumicite. Pumice is considered a glass because it has no crystal structure, pumice varies in density according to the thickness of the solid material between the bubbles, many samples float in water. After the explosion of Krakatoa, rafts of pumice drifted through the Pacific Ocean for up to 20 years, in fact, pumice rafts disperse and support several marine species. In 1979,1984 and 2006, underwater volcanic eruptions near Tonga created large pumice rafts, there are two main forms of vesicles. Most pumice contains tubular microvesicles that can impart a silky or fibrous fabric, the elongation of the microvesicles occurs due to ductile elongation in the volcanic conduit or, in the case of pumiceous lavas, during flow. The other form of vesicles are subspherical to spherical and result from high pressure during eruption. Pumice is widely used to make concrete or insulative low-density cinder blocks
38.
Travertine
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Travertine is a form of limestone deposited by mineral springs, especially hot springs. Travertine often has a fibrous or concentric appearance and exists in white, tan, cream-colored and it is formed by a process of rapid precipitation of calcium carbonate, often at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites, stalagmites, and it is frequently used in Italy and elsewhere as a building material. Travertine is a sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters. Similar deposits formed from water are known as tufa. The word travertine is derived from the Italian travertino, itself a derivation of the Latin tiburtinus ‘of Tibur’ and its namesake is also the origin of Tivoli, a district near Rome. Modern travertine is formed from geothermally heated supersaturated alkaline waters, with raised pCO2, on emergence, waters degas CO2 due to the lower atmospheric pCO2, resulting in an increase in pH. Since carbonate solubility decreases with increased pH, precipitation is induced, precipitation may be enhanced by factors leading to a reduction in pCO2, for example increased air-water interactions at waterfalls may be important, as may photosynthesis. Precipitation may also be enhanced by evaporation in some springs, both calcite and aragonite are found in hot spring travertines, aragonite is preferentially precipitated when temperatures are hot, while calcite dominates when temperatures are cooler. When pure and fine, travertine is white, but often it is brown to yellow due to impurities, travertine may precipitate out directly onto rock and other inert materials as in Pamukkale or Yellowstone for example. The latter has a historic value, because it was one of the quarries that Gian Lorenzo Bernini selected material from to build the famous Colonnade of St. Peters Square in Rome in 1656-1667. Michaelangelo also chose travertine as the material for the ribs of the dome of St Peters Basilica. Travertine derives its name from the town, known as Tibur in ancient Roman times. The ancient name for the stone was lapis tiburtinus, meaning tibur stone, detailed studies of the Tivoli and Guidonia travertine deposits revealed diurnal and annual rhythmic banding and laminae, which have potential use in geochronology. Cascades of natural lakes formed behind travertine dams can be seen in Pamukkale, Turkey, in Central Europes last post-glacial palaeoclimatic optimum, huge deposits of tufa formed from karst springs. On a smaller scale, these karst processes are still working, travertine has been an important building material since the Middle Ages. Travertine has formed sixteen huge, natural dams in a valley in Croatia known as Plitvice Lakes National Park, clinging to moss and rocks in the water, the travertine has built up over several millennia to form waterfalls up to 70 m in height. In the U. S. the most well-known place for travertine formation is Yellowstone National Park, Oklahoma has two parks dedicated to this natural wonder
39.
Energetically modified cement
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Energetically modified cements are a class of cementitious materials made from pozzolans, silica sand, blast furnace slag, or Portland cement. The term energetically modified cement refers to a class of materials which have been produced using a special activation process. This process is entirely mechanical, as opposed to thermal, and is carried out by grinding the materials to increase binding capacity. EMCs can be produced with less energy and carbon dioxide production than traditional cements, each type of energetically modified cement has its own performance characteristics, including mechanical load. EMC products have been tested by independent labs. The term energetically modified cement was first used in Sweden, where the EMC Activation process was developed in 1992 by Vladimir Ronin at Luleå University of Technology, the term was introduced in a paper by Ronin et al. in 1993. The process was refined by Ronin and others, including Lennart Elfgren, continuing academic work and research self-healing properties of energetically modified cements is ongoing at LTU. The research work connected with EMCs has received awards from the Elsa ō Sven Thysells stiftelse för konstruktionsteknisk forskning of Sweden, many of the end products of pozzolanic chemistry exhibit a hardness greater than 7.0 on the Mohs scale. EMC Activation is a process which increases a pozzolans chemical affinity for pozzolanic reactions and this is leads to faster and greater strength development of the resulting concrete, at higher replacement ratios, than untreated pozzolans. These highly reactive pozzolans can yield further stabilisation benefits upon the pozzolanic reaction-pathways, in concrete, Portland cement combines with water to produce a stone-like material through a complex series of chemical reactions, the full mechanics of which are still not fully understood. That chemical process, called mineral hydration, forms two cementing compounds in the concrete, calcium silicate hydrate and calcium hydroxide, the crystal structure of C-S-H in cement paste has not been fully resolved yet and there is still ongoing debate over its nanostructure. Calcium hydroxide, which in concrete chemistry is also as Portlandite. In comparison to calcium silicate hydrate, Portlandite is relatively porous, permeable and it is also sectile, with flexible cleavage flakes. Portlandite is soluble in water, to yield a solution which can compromise a concretes resistance to acidic attack. Portlandite makes up about 25% of concrete made with Portland cement without pozzolanic cementitious materials, at its softest, calcium carbonate can form in concrete as chalk. Like Portlandite, calcium carbonate in mineral form can also be porous, permeable and with a resistance to acid attack. This results in a denser, less permeable and more durable concrete, pozzolanic cement chemistry is complex and per se is not constrained by the foregoing pathways. For example, strätlingite is metastable, which in a high temperature, however, adding high-reactivity pozzolans into the concrete mix prevents such a conversion reaction
40.
Roman brick
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Roman brick can refer either to a type of brick used in Ancient Roman architecture and spread by the Romans to the lands they conquered, or to a modern type inspired by the ancient prototypes. In both cases, it characteristically has longer and flatter dimensions than those of standard modern bricks, the Romans only developed fired clay bricks under the Empire, but had previously used mud brick, dried only by the sun and therefore much weaker and only suitable for smaller buildings. Roman brick was almost invariably of a lesser height than modern brick, shapes included square, rectangular, triangular and round, and the largest bricks found have measured over three feet in length. Ancient Roman bricks had a size of 1½ Roman feet by 1 Roman foot. Other brick sizes in Ancient Rome included 24 x 12 x 4, Ancient Roman bricks found in France measured 8 x 8 x 3. The Constantine Basilica in Trier is constructed from Roman bricks 15 square by 1½ thick, the Romans perfected brick-making during the first century of their empire and used it ubiquitously, in public and private construction alike. The Romans took their brickmaking skills everywhere they went, introducing the craft to the local populations, the Roman legions operated mobile kilns and introduced bricks to many parts of the empire. Roman bricks are stamped with the mark of the legion that supervised their production. The use of bricks in southern and western Germany, for example, can be traced back to traditions already described by the Roman architect Vitruvius, although he probably refers to mud brick. In the British Isles, the introduction of Roman brick by the Ancient Romans was followed by a 600–700 year gap in major brick production, when building in masonry, the Romans often interspersed the stonework at set intervals with thin courses of bricks, sometimes known as bonding tiles. This practice gave the added stability. It also had an aesthetic effect of creating a polychromatic appearance. This has been described as one of the earliest exercises in archaeological typology, after the Western Roman Empire fell in the 5th century many of the commercial stone quarries in Europe were abandoned. This led to a consistent pattern of reuse of Roman building materials throughout the several hundred years. Like much of the Roman stone, Roman bricks were gathered for reuse throughout this period, for example, in the 10th century the abbots of St. Albans gathered enough Roman brick during this time period to have their own stockpile of the building material. When brick production resumed in earnest on the British Isles, the 1½ to 2 height of the Roman-style brick gradually increased during the early Medieval period, Brick from the Ancient Roman Empire was commonly reused in medieval Europe as well as in later periods. This reuse can be found across the former Roman Empire, in Great Britain, where construction materials are less plentiful, Roman structures were quarried for their stone and brick and it was commonly reused. Examples of this type of reuse in Great Britain can be found in Anglo-Saxon churches at Brixworth, Corbridge, St. Martins, Canterbury, and St Nicholas, Leicester, modern Roman bricks were introduced at the beginning of the 20th century
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International Standard Book Number
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The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker
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The Washington Post
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The Washington Post is an American daily newspaper. It is the most widely circulated newspaper published in Washington, D. C. and was founded on December 6,1877 and its current slogan is Democracy Dies in Darkness. Located in the city of the United States, the newspaper has a particular emphasis on national politics. Daily editions are printed for the District of Columbia, Maryland, the newspaper is published as a broadsheet, with photographs printed both in color and in black and white. The newspaper has won 47 Pulitzer Prizes and this includes six separate Pulitzers awarded in 2008, the second-highest number ever awarded to a single newspaper in one year, second only to The New York Times seven awards in 2002. Post journalists have also received 18 Nieman Fellowships and 368 White House News Photographers Association awards, in years since, its investigations have led to increased review of the Walter Reed Army Medical Center. In 2013, its owners, the Graham family, sold the newspaper to billionaire entrepreneur. The newspaper is owned by Nash Holdings LLC, a holding company Bezos created for the acquisition, the Washington Post is generally regarded as one of the leading daily American newspapers, along with The New York Times and The Wall Street Journal. The Post has distinguished itself through its reporting on the workings of the White House, Congress. It is one of the two daily broadsheets published in Washington D. C. the other being its smaller rival The Washington Times, unlike The New York Times and The Wall Street Journal, The Washington Post does not print an edition for distribution away from the East Coast. In 2009, the newspaper ceased publication of its National Weekly Edition, the majority of its newsprint readership is in District of Columbia and its suburbs in Maryland and Northern Virginia. The Sunday Style section differs slightly from the weekday Style section, it is in a tabloid format, and it houses the reader-written humor contest The Style Invitational. Additional weekly sections appear on weekdays, Health & Science on Tuesday, Food on Wednesday, Local Living on Thursday, the latter two are in a tabloid format. In November 2009, it announced the closure of its U. S. regional bureaus—Chicago, Los Angeles and New York—as part of a focus on. political stories. The newspaper has bureaus in Maryland and Virginia. While its circulation has been slipping, it has one of the highest market-penetration rates of any metropolitan news daily, for many decades, the Post had its main office at 1150 15th Street NW. This real estate remained with Graham Holdings when the newspaper was sold to Jeff Bezos Nash Holdings in 2013, Graham Holdings sold 1150 15th Street for US$159 million in November 2013. The Washington Post continued to lease space at 1150 L Street NW, in May 2014, The Washington Post leased the west tower of One Franklin Square, a high-rise building at 1301 K Street NW in Washington, D. C
