1868 résultats pour "this"
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Roma Roman A legendary figure who came to be
worshiped as a goddess, Roma was the personification
of the city of Rome.
became Rome. The first hill people settled appears to have been the Capitoline Hill. Archaeologists have discovered some of the oldest temples to the supreme Roman god, Jupiter, on this hill. According to legend, it was on this hill that Romulus founded his city. The next hill that settlers developed was the nearby Palatine, 1,250 yards to the southeast of the Capitoline Hill. Legend says that Evander, a leader from the Arcadia region of ancient Greece, settled this hill even before Romulus was...
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Electron
I
INTRODUCTION
Models of the Atom
Once scientists discovered the electron, they set out to explain how electrons behave in atoms.
Electron Density and Orbital ShapesAtomic orbitals are mathematical descriptions of where the electrons in an atom (or molecule) are most likely to be found.These descriptions are obtained by solving an equation known as the Schrödinger equation, which expresses ourknowledge of the atomic world. As the angular momentum and energy of an electron increases, it tends to reside indifferently shaped orbitals. The orbitals corresponding to the three lowest energy states are s, p, and d, respectively....
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Atificiel
Sustainability 2019,11 , 189 2 of 24Since the 1980s, many research was conducted to minimize the error of prediction through a method dubbed as gradient descent. This method is referred to as a Backpropagation algorithm for the training of the ANNs and it was applied to solve problems in different domains using few hidden layers [ 5,6]. Today, the availability of data has introduced the concept of machine learning as a subcategory to AI. Machine learning implies coding the computers to behave l...
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Commentary: Maiden Voyage
as the author says 'stable doors', and the outside of it is really emphasized with the description of this landscape which is also apparently hot as hell since the narrator is claiming that 'the soles of my shoes began to burn and I looked round vainly for some shady place', and accentuates the difference between the two different cultures, the European one et the Chinese one. However, even though this place is described as being dangerous and not really safe, it's still looking peaceful and bea...
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Development (biology) - biology.
Understanding the molecular machinery within cells gives biologists a direct basis for understanding growth, because growth is the synthesis of new protoplasm, andbiologists know the basic mechanism of this synthesis. One key gap, however, exists in this knowledge. Biologists want to know not only how substances aresynthesized but also how growth is controlled so that the proportions of an animal or plant remain consistent from generation to generation. The direction and amountof growth, which a...
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Understanding of Art
sub-structure of a society (see Marx, K. ). The understanding of the work that this would yield would not, however, be relevant to judgments of artistic merit. In the next two sections we shall look more closely at such attempts toseparate understanding and evaluation. 4 Understanding, truth and morality Much of the debate about art and understanding is a debate about how much of what might rightly be called an understanding of art is relevant toquestions of the evaluation of art. Bell, for e...
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Native American Policy.
of white settlement dominated policy during the second quarter of the 19th century. IV REMOVAL PERIOD The idea of moving Native Americans to a different part of the country was not new. After the Louisiana Purchase in 1803, President Thomas Jefferson had suggestedthat tracts of land in this vast new territory could be given to native peoples if they agreed to cede their lands in the eastern part of the country. Transfers occurred in apiecemeal way, but no consistent removal program developed u...
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The Scarlett letter
The Scarlet Letter is an american romantic novel of fiction, written by Nathaniel Hawthorne, published in the mid-nineteenth century. It is considered to be his best work. Nathaniel Hawthorne was an American novelist and short story writer from the nineteen century. He is a dark romantic (anti-transcendentalist) which means that he explores the psychological effects of guilt and sin, madness, derangement in the human psyche. The Scarlett letter is marked by this exploration. The st...
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Animal Behavior - biology.
The first motor program analyzed in much detail was the egg-rolling response of geese. When a goose sees an egg outside its nest, it stares at the egg, stretches itsneck until its bill is just on the other side of the egg, and then gently rolls the egg back into the nest. At first glance this seems a thoughtful and intelligent piece ofbehavior, but it is a mechanical motor program; almost any smooth, rounded object (the sign stimulus) will release the response. Furthermore, removal of the egg on...
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Simón Bolívar.
Again, he expressed his dislike of federalism and his preference for strong centralized republics. He felt that Venezuela and New Granada should unite into a centralizedrepublic, which would be called Colombia. This new republic would have an elected executive and a legislature consisting of an elected lower house and a hereditaryupper house. Lastly, he spoke about the need for a union of all the countries in Spanish America to ensure prosperity and security after independence. IV BOLÍVAR AS MI...
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Relativity
I
INTRODUCTION
Albert Einstein
In 1905 German-born American physicist Albert Einstein published his first paper outlining the theory of relativity.
in calculating very large distances or very large aggregations of matter. As the quantum theory applies to the very small, so the relativity theory applies to the verylarge. Until 1887 no flaw had appeared in the rapidly developing body of classical physics. In that year, the Michelson-Morley experiment, named after the American physicistAlbert Michelson and the American chemist Edward Williams Morley, was performed. It was an attempt to determine the rate of the motion of the earth through t...
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Russian Revolutions of 1917 (Histoire) .
as Marxists. They believed that the working class—with its struggles to organize trade unions and to bring about political reforms of benefit to the majority ofpeople—would become the primary force for revolutionary change. The Russian Marxists formed the Russian Social Democratic Labor Party (RSDLP) in 1898. By 1903,however, the RSDLP had split into two factions. The faction called the Bolsheviks (from the Russian word for “majority”), led by Vladimir Ilich Lenin, favored a more centralized a...
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Pyramids (Egypt) - geography.
limestone debris left over from the construction work. When the workers had completed the pyramid and installed the pyramidion, or cap stone, ramps still covered the surface of the pyramid. As the workers dismantled the ramps from the top down, they slowly exposed the pyramid’s stone surface, which stonemasons smoothed and polished. When the ramp was gone, the pyramid wasdisplayed in its full majesty. B Interior The interior of the Great Pyramid is complex, with a series of passages leading t...
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Pyramids (Egypt) - History.
limestone debris left over from the construction work. When the workers had completed the pyramid and installed the pyramidion, or cap stone, ramps still covered the surface of the pyramid. As the workers dismantled the ramps from the top down, they slowly exposed the pyramid’s stone surface, which stonemasons smoothed and polished. When the ramp was gone, the pyramid wasdisplayed in its full majesty. B Interior The interior of the Great Pyramid is complex, with a series of passages leading t...
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Cancer (medicine).
unable to repair the DNA damage, p53 instructs the cell to undergo programmed cell death, or apoptosis , putting a stop to runaway cell division before it starts. Programmed cell death is a normal part of cell life and is tightly controlled by many genes, primarily p53. In a cancerous cell, one or more mutations prevent these genes from doing their jobs. When mutated, p53 allows a cell to continue to divide, even with damaged DNA.This can lead to additional mutations in proto-oncogenes or tumor...
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From "The Metamorphosis" - anthology.
As all this was running through his mind at top speed without his being able to decide to leave his bed—the alarm clock had just struck a quarter to seven—therecame a cautious tap at the door behind the head of his bed. 'Gregor,' said a voice—it was his mother's—'it's a quarter to seven. Hadn't you a train to catch?' Thatgentle voice! Gregor had a shock as he heard his own voice answering hers, unmistakably his own voice, it was true, but with a persistent horrible twittering squeakbehind it lik...
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Islam.
commanded to face the Kaaba, an ancient shrine in the city of Mecca. The Qur’an also refers to the recitation of parts of the Qur’an as a form of prayer. However, evenwith its numerous references, the Qur’an alone does not give exact instructions for this central ritual of prayer. The most detailed descriptions of the rituals for prayer derive from the example set by the prophet Muhammad and are preserved in later Islamic traditions. Somedetails of these rituals vary, however all Muslims agree t...
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Quantum Theory
I
INTRODUCTION
Quantum Theory, in physics, description of the particles that make up matter and how they interact with each other and with energy.
electron in the same way a particle with momentum would: It bumps the electron and changes the electron’s path. The light is also affected by the collision as though itwere a particle, in that its energy and momentum changes. Momentum is a quantity that can be defined for all particles. For light particles, or photons, momentum depends on the frequency, or color, of the photon, which in turndepends on the photon’s energy. The energy of a photon is equal to a constant number, called Planck’s cons...
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English Literature
I
INTRODUCTION
English Literature, literature produced in England, from the introduction of Old English by the Anglo-Saxons in the 5th century to the present.
evident. That feature is typical of other Old English literature, for almost all of what survives was preserved by monastic copyists. Most of it was actually composed byreligious writers after the early conversion of the people from their faith in the older Germanic divinities. Sacred legend and story were reduced to verse in poems resembling Beowulf in form. At first such verse was rendered in the somewhat simple, stark style of the poems of Caedmon, a humble man of the late 7th century who w...
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Nuclear Weapons.
Regardless of the method used to attain a supercritical assembly, the chain reaction proceeds for about a millionth of a second, liberating vast amounts of heat energy.The extremely fast release of a very large amount of energy in a relatively small volume causes the temperature to rise to tens of millions of degrees. The resultingrapid expansion and vaporization of the bomb material causes a powerful explosion. VI PRODUCTION OF FISSILE MATERIAL Much experimentation was necessary to make the p...
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Sun - astronomy.
A The Sun’s Place in the Milky Way The Milky Way Galaxy contains about 400 billion stars. All of these stars, and the gas and dust between them, are rotating about a galactic center. Stars that arefarther away from the center move at slower speeds and take longer to go around it. The Sun is located in the outer part of the galaxy, at a distance of 2.6 × 10 17 km (1.6 × 10 17 mi) from the center. The Sun, which is moving around the center at a velocity of 220 km/s (140 mi/s), takes 250 million y...
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Atom - chemistry.
Atoms have several properties that help distinguish one type of atom from another and determine how atoms change under certain conditions. A Atomic Number Each element has a unique number of protons in its atoms. This number is called the atomic number (abbreviated Z). Because atoms are normally electrically neutral,the atomic number also specifies how many electrons an atom will have. The number of electrons, in turn, determines many of the chemical and physical properties ofthe atom. The ligh...
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Acquired Immunodeficiency Syndrome.
child transmission is particularly prevalent in Africa. D Misperceptions About HIV Transmission The routes of HIV transmission are well documented by scientists, but health officials continually grapple with people’s unfounded fears concerning the potential for HIVtransmission by other means. HIV differs from other infectious viruses in that it dies quickly if exposed to the environment. No evidence has linked HIV transmission tocasual contact with an infected person, such as a handshake, huggi...
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Chemistry - chemistry.
parts of oxygen by weight, which is a ratio of about 1 to 8, regardless of whether the water came from the Mississippi River or the ice of Antarctica. In other words, acompound has a definite, invariable composition, always containing the same elements in the same proportions by weight; this is the law of definite proportions. Many elements combine in more than one ratio, giving different compounds. In addition to forming water, hydrogen and oxygen also form hydrogen peroxide.Hydrogen peroxide h...
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Cold War.
With this, all the countries of Eastern Europe were under Communist control, and the creation of the Soviet bloc was complete. The events of 1948 contributed to agrowing conviction among political leaders in both the United States and the USSR that the opposing power posed a broad and fundamental threat to their nation’sinterests. The Berlin blockade and the spread of Communism in Europe led to negotiations between Western Europe, Canada, and the United States that resulted in the NorthAtlantic...
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Cold War .
With this, all the countries of Eastern Europe were under Communist control, and the creation of the Soviet bloc was complete. The events of 1948 contributed to agrowing conviction among political leaders in both the United States and the USSR that the opposing power posed a broad and fundamental threat to their nation’sinterests. The Berlin blockade and the spread of Communism in Europe led to negotiations between Western Europe, Canada, and the United States that resulted in the NorthAtlantic...
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History of Astronomy - astronomy.
Egypt, the Sun was directly overhead at noon. On the same date and time in Alexandria, Egypt, the Sun was about 7 degrees south of zenith. With simple geometryand knowledge of the distance between the two cities, he estimated the circumference of the Earth to be 250,000 stadia. (The stadium was a unit of length, derivedfrom the length of the racetrack in an ancient Greek stadium. We have an approximate idea of how big an ancient Greek stadium was, and based on that approximationEratosthenes was...
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Cold War - U.
With this, all the countries of Eastern Europe were under Communist control, and the creation of the Soviet bloc was complete. The events of 1948 contributed to agrowing conviction among political leaders in both the United States and the USSR that the opposing power posed a broad and fundamental threat to their nation’sinterests. The Berlin blockade and the spread of Communism in Europe led to negotiations between Western Europe, Canada, and the United States that resulted in the NorthAtlantic...
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Nicklaus-Watson Match.
until 1977, primarily because golf officials felt that there weren't enough hotel rooms in the area to attract and accommodate the crowds. But officials finally relented,deciding that the majestic course deserved to stage golf's most noble tournament. The sun shone brightly over this scene for the July event. Nicklaus and Watson were both on the leader board after the first two rounds with identical scores of 68-70-138. Their dramatic play began in the third round, on Friday. Nicklaus jumped...
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Compositionality
sentence construction, an operation on meanings, such that the meaning of any sentence is mechanically determined by applying the operations on meanings (given by the rules used in constructing the sentence) to the meanings of the simple parts. (Often a host of extra restrictions are incorporated. For example: the operations may be limited to applying function to argument; the order in which operations are applied may be settled by the structure of the sentence.) Some see such principles as prov...
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Roman Catholic Church.
comprehensiveness of its doctrinal tradition. Locating its beginnings in the earliest Christian communities and refusing to acknowledge any decisive break in its history,the Roman Catholic Church considers itself heir to the theological traditions of the apostolic, patristic, medieval, and modern periods. The church does not in principleexclude any theological method, and since the encyclical of Pope Pius XII Divino Afflante Spiritu (1943) it has officially sanctioned modern principles of exeg...
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Canadian Pacific Railway - Canadian History.
roads constructed inland from the lakeshore. However, this changed with the outbreak in Saskatchewan of the Northwest Rebellion by Louis Riel and his supportersagainst the authority of the Canadian government in March 1885. Despite the fact that the railway was not completed, a contingent of troops was able to reachWinnipeg from Montréal in only seven days, much faster than they could have gone overland, and get from there to Saskatchewan in time to successfully put down therebellion. This actio...
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Mammal - biology.
On land, mammals live in many different habitats, and at a wide range of altitudes. Many mammals dig burrows as refuges or as places to raise their young, but somehave developed a largely subterranean lifestyle, feeding on small animals or plant roots beneath the soil's surface. These animals, including moles and mole-rats, digthrough the ground either with spadelike front paws or with their teeth, and they detect danger by being highly sensitive to vibrations transmitted through the soil.Most m...
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James Monroe.
In October 1786, Monroe resigned from Congress and settled with his bride in Fredericksburg, Virginia, where he began a law practice. His retirement from politics wasbrief. He was soon elected to the town council, and then once again to the Virginia legislature. However, Monroe never lost touch with national politics. He corresponded regularly with both Jefferson and Madison. In 1786 Monroe attended the AnnapolisConvention, which had been called to consider interstate commerce and other matters...
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James Monroe - USA History.
In October 1786, Monroe resigned from Congress and settled with his bride in Fredericksburg, Virginia, where he began a law practice. His retirement from politics wasbrief. He was soon elected to the town council, and then once again to the Virginia legislature. However, Monroe never lost touch with national politics. He corresponded regularly with both Jefferson and Madison. In 1786 Monroe attended the AnnapolisConvention, which had been called to consider interstate commerce and other matters...
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Fascism.
values as coming before a radical political transformation. Others argue that a radical political transformation will then be followed by a change in values. Fascists claimthat the nation has entered a dangerous age of mediocrity, weakness, and decline. They are convinced that through their timely action they can save the nation fromitself. Fascists may assert the need to take drastic action against a nation's 'inner' enemies. Fascists promise that with their help the national crisis will end an...
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The Souls of Black Folk by W.
in amused contempt and pity. One ever feels his two-ness,—an American, a Negro; two souls, two thoughts, two unreconciled strivings; two warring ideals in onedark body, whose dogged strength alone keeps it from being torn asunder. The history of the American Negro is the history of this strife—this longing to attain self-conscious manhood, to merge his double self into a better and truer self. Inthis merging he wishes neither of the older selves to be lost. He would not Africanize America, f...
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Ancient Egypt.
around 4500 BC. The style and decoration of the pottery found at these sites differ from those of pottery found in Upper Egypt. The northern type eventually fell out of use. Other differences between the peoples in Upper Egypt and Lower Egypt include the nature of their architecture and the arrangements for burial of the dead, thelatter perhaps signifying differing religious beliefs. B Unification and Early Dynastic Period By 3500 BC, the settlement of Hierakonpolis, located on the west bank...
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Western Music
I
INTRODUCTION
Bizet's Carmen
Georges Bizet's Carmen, first performed in Paris in 1875, was a milestone in the history of French opera.
church ceremonies during the period from the 5th to the 7th century. Roman chant became known as Gregorian chant after Pope Gregory I, the Great, who may havecomposed some of the melodies and who actively encouraged an orderly, ritualized use of music by the church. Because Gregory and later popes preferred Gregorianchant to the varieties that had developed elsewhere in Europe, Gregorian chant eventually superseded most of the others. Gregorian and other chant styles arepreserved in many manuscr...
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Paul Martin.
VI CONFLICT WITH THE PRIME MINISTER Martin’s success could not have been achieved without the support he received from Jean Chrétien. Yet relations between the two men continued to deteriorate. In partthis was because of their continuing disagreement about how best to deal with the separatist challenge in Québec. In the 1993 election, a majority of Québec seats hadgone to the Bloc Québécois, and in 1994 the provincial separatist party, the Parti Québécois, won election on a platform promising...
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Paul Martin - Canadian History.
VI CONFLICT WITH THE PRIME MINISTER Martin’s success could not have been achieved without the support he received from Jean Chrétien. Yet relations between the two men continued to deteriorate. In partthis was because of their continuing disagreement about how best to deal with the separatist challenge in Québec. In the 1993 election, a majority of Québec seats hadgone to the Bloc Québécois, and in 1994 the provincial separatist party, the Parti Québécois, won election on a platform promising...
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French Revolution.
B2 Assembly of Notables and Estates-General To pressure the parlements into accepting the plan, Calonne decided to gain prior approval of it from an Assembly of Notables—a group of hand-picked dignitaries hethought would sympathize with his views. But Calonne had badly miscalculated. Meeting in January 1787, the assembly refused to believe that a financial crisis reallyexisted. They had been influenced by Necker’s argument that state finances were sound and suspected that the monarchy was only...
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French Revolution .
B2 Assembly of Notables and Estates-General To pressure the parlements into accepting the plan, Calonne decided to gain prior approval of it from an Assembly of Notables—a group of hand-picked dignitaries hethought would sympathize with his views. But Calonne had badly miscalculated. Meeting in January 1787, the assembly refused to believe that a financial crisis reallyexisted. They had been influenced by Necker’s argument that state finances were sound and suspected that the monarchy was only...
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Meteorology.
to find the corresponding relative humidity and dew-point temperature. III SPECIAL METEOROLOGICAL INSTRUMENTS Meteorologists have developed several sophisticated instruments that measure multiple physical characteristics of the air simultaneously and at more than one location.The most important of these special instruments are radiosondes, Doppler radar, and weather satellites. A Radiosonde A radiosonde measures air temperature, air pressure, and humidity from the earth’s surface up to an alt...
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Ancient Egypt.
around 4500 BC. The style and decoration of the pottery found at these sites differ from those of pottery found in Upper Egypt. The northern type eventually fell out of use. Other differences between the peoples in Upper Egypt and Lower Egypt include the nature of their architecture and the arrangements for burial of the dead, thelatter perhaps signifying differing religious beliefs. B Unification and Early Dynastic Period By 3500 BC, the settlement of Hierakonpolis, located on the west bank...
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Ancient Egypt - USA History.
around 4500 BC. The style and decoration of the pottery found at these sites differ from those of pottery found in Upper Egypt. The northern type eventually fell out of use. Other differences between the peoples in Upper Egypt and Lower Egypt include the nature of their architecture and the arrangements for burial of the dead, thelatter perhaps signifying differing religious beliefs. B Unification and Early Dynastic Period By 3500 BC, the settlement of Hierakonpolis, located on the west bank...
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Pornography.
censorship. Congress passed 20 obscenity laws between 1842 and 1956, most of which were variations of or amendments to the original Comstock Law. Later, Congress passed aseries of antipornography and anti-indecency laws dealing with new forms of technology and with the protection of children. The Protection of Children Against SexualExploitation Act of 1977 prohibits anyone from employing or inducing a minor to participate in sexual conduct or in the making of pornography. In 1988 Congresspassed...
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Manhattan Project - U.
other possible uses of nuclear energy, such as using uranium to operate large power plants or, perhaps, as power sources for ships or submarines. Then Nazi Germanyinvaded Poland on September 1, 1939, and Europe plunged into war. The scientists realized that any plans to build large-scale nuclear power plants would have to waituntil the war was over. Two weeks after the invasion of Poland, Hitler made a radio speech in which he threatened Britain with “a weapon against which there is no defense.”...
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Hydrogen - chemistry.
Hydrogen gas does not usually react with other chemicals at room temperature. That is, it does not split into two hydrogen atoms to combine with other chemicals. Thebond between the hydrogen atoms is very strong and can only be broken with a large amount of energy. However, when heated with a flame or a spark, hydrogen gaswill react violently with oxygen in the air to produce water in the following reaction: 2H2 + O 2 → 2H 2O This chemical equation shows that two hydrogen molecules (H 2) and o...
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Heart.
situation. A Cardiac Cycle Although the right and left halves of the heart are separate, they both contract in unison, producing a single heartbeat. The sequence of events from the beginning ofone heartbeat to the beginning of the next is called the cardiac cycle. The cardiac cycle has two phases: diastole, when the heart’s chambers are relaxed, and systole,when the chambers contract to move blood. During the systolic phase, the atria contract first, followed by contraction of the ventricles. T...