lunes, 4 de abril de 2011

Renewable Energy


Now that oil prices are getting more and more expensive different countries are focusing on Renewable energy as an alternative energy source. Many countries now are depending on non-renewable energy source like; coal, oil and natural gas to supply most of their energy needs, but reliance on this non-renewable energy or fossil fuels presents a big problem. World supply of fossil fuels is limited, eventually the world will run out of it and it will even be more costly to get the remaining supply of those fossil fuels. Fossil fuels are hydrocarbon deposit, such as petroleum, coal or natural gas, formed over millions and millions of years by the action of heat from the Earth's core and pressure from rock and soil on the remains(or "fossils") of dead plants and animals.

Renewable and non-renewable energy sources are used to produce a secondary energy sources which includes electricity and hydrogen. We use this energy sources to generate electricity we need for our homes, businesses, factories, cars etc.

Two Sources of Energy:



·         Renewable Energy - energy source that can be replenished in a short period of time. Sources; Wind, Geothermal, Water, Biomass, Solar

·         Non-Renewable Energy - energy source that we are using up and cannot recreate in a short period of time. Sources; Oil, Coal, Natural Gas, Nuclear

a. Negative Effect of Non-Renewable Energy Fossil Fuels:

·         Fossil Fuels causes air, water and soil pollution.

·         It also produces greenhouse gases that contribute to global warming.

b. Benefits of Renewable Energy Source:

·         Renewable energy sources offer clean alternative to fossil fuels.

·         RE produces little or no pollution or greenhouse gases.

·         RE will never run out

Kinds of Renewable Energy:

·         Solar energy which comes from the sun can be turned as electricity and heat. Solar panels on the roofs of houses, building and other establishment are use to store the solar energy. The sun's energy harnessed by the panels runs generators which provide electricity. There are stand-alone solar panels that you can put in your yard to save the sun's energy in a generator.

·         Geothermal energy is an energy that comes from the heat inside the earth. It's simple technology that involves boring a hole into the ground to take the heat from the earth's crust. The heat that comes off is used to heat water and make steam to power generators to make electricity.

·         Biomass energy is from the plant and trees. This energy alternative makes use of husks that come off rice after it is harvested and the waste from the corn. This "biomass" can be burned in a power station built for such a purpose. It emits less pollution than if the waste was left to rot, because it would produce a lot of methane.

Sources: Wood (most common source), plants, agricultural waste, industrial waste, even methane gas from community landfills.

Uses: fuel for transportation or to manufacture product that would otherwise use fossil fuels.

·         Water Energy - the natural evaporation/precipitation cycle makes water a renewable source of energy. The heat of the sun causes water in lakes and ocean to evaporate and form clouds. The water then falls back to earth as rain or snow, and goes to the rivers and streams that flow back to the ocean. Moving water can be used to power water wheels that drive mechanical processes. Water Wheels are useful for generating mechanical energy to grind grain or saw wood, but are not practical for generating electricity because it is bulky and slow. Water energy emits about 30 times less greenhouse gas than modern natural gas power plants and 60 times less than coal-fired plant, which makes it a clean source of energy.

·         Wind Energy is captured by wind turbines and used to generate electricity. The costs of wind energy are going down as mass manufacture of turbines becomes more accepted. It costs the same as setting up a new coal or nuclear power station. More importantly, external cost to health care and the effects of acid rain are 50times less than when using coal.







Apollo and Daphne is a story from ancient  Greek mythology, retold by Hellenistic  and Roman  authors in the form of an amorous vignette;

" Apollo and Daphne " by   Antonio Pollaiuolo 
The curse of Apollo, the god of the sun and music, was brought onto him when he insulted the young Eros for playing with bow and arrows. 
Apollo was a great warrior and said to him, "What have you to do with warlike weapons, saucy boy? Leave them for hands worthy of them. Behold the conquest I have won by means of them over the vast serpent who stretched his poisonous body over acres of the plain! Be content with your torch, child, and kindle up your flames, as you call them, where you will, but presume not to meddle with my weapons"
The petulant Eros took two arrows, one of gold and one of lead . The gold one was supposed to incite love, while the lead one was supposed to incite hatred. With the leaden shaft, Eros shot the nymph Daphne and with the golden one, he shot Apollo through the heart. Apollo was seized with love for the maiden, Daphne, and she in turn abhorred him. In fact, she spurned her many potential lovers, preferring instead woodland sports and exploring the woods. Her father, Peneus, demanded that she get married so that she may give him grandchildren. However, she begged her father to let her remain unmarried, like Apollo's sister, Artemis.
He warned her saying, "Your own face will forbid it." By saying this he meant that she was too beautiful to keep all her potential lovers away forever.
Apollo continually followed her, begging her to stay, but the nymph continued her flight. They were evenly matched in the race until Eros intervened and helped Apollo gain upon Daphne.
Seeing that Apollo was bound to catch her, she called upon her father, "Help me, Peneus! Open the earth to enclose me, or change my form, which has brought me into this danger!"
Suddenly, her skin turned into bark, her hair became leaves, and her arms were transformed into branches. She stopped running as her feet became rooted to the ground. Apollo embraced the branches, but even the branches shrank away from him. Since Apollo could no longer take her as his wife, he vowed to tend her as his tree, and promised that her leaves would decorate the heads of leaders as crowns, and that her leaves were also to be depicted on weapons. Apollo also used his powers of eternal youth and immortality to render her ever green. Since then, the leaves of the Bay laurel tree have never known decay.

AMERICA INDEPENDENCE - CONTEMPORANEAN HISTORY



Colonial America


1. EUROPEAN COLONIZATION AND SETTLEMENT

Viewed today, the process of colonization and settlement of North America was an invasion of territory that had been controlled and settled for centuries by the indigenous population. The arrival of the Europeans constituted an intrusion, which, in the long term, the American Indians were unable to resist.

Main Reasons of Colonization and Settlement:

Ø      The Europeans were initially drawn to America to acquire wealth and to establish new homes. European sovereigns rushed to claim as much territory as possible in order to found settlements on the territory.
Ø      English colonial policy promoted domestic industry, foreign trade, fisheries, and shipping by establishing colonial settlements in the New World and exploiting its resources through commercial companies
Ø      The growing urge to colonize was due to a number of factors, which included international rivalry and the propagation of religion - a desire to convert the indigenous inhabitants of America to Christianity. There were also increasing numbers of religious and political dissenters who were seeking refuge, and individuals looking for adventure and new opportunities, and who wanted to own land. The main impulse behind colonization, however, was to make profit in the New World.

Economy:

Ø      European countries engaged in the system of mercantilism. This meant state control and intervention, and the regulation of economic activities in the colonies. The aim was to accumulate wealth for the European powers at the colonies' expense. The colonies supplied food for themselves (auto supply) and their role was to produce raw materials and food for the metropolis, and to provide a market for it. Industrial activities were forbidden in the colonies in order to make them dependable on the exports of the metropolis.
Ø      The degree of colonial control exerted depended on the nation and on the period. In the initial settlements, English control over the colonies was minimal. However, as the colonies grew and became more prosperous, the British realized that the colonies could provide increased trade and, therefore, they tightened the economic control by implementing regulatory policies, thereby changing the balance of the relationship.

2. BRITISH POLICY WITH THE AMERICAN COLONIES UNTIL 1763

Virginia became the first of the royal colonies under a system of government that included a governor appointed by the king and a colonial assembly.
Three types of colonial government emerged: royal, corporate, and proprietary.
The king directed colonial policy until the outbreak of the first English civil war, when the Long Parliament assumed control. Between 1645 and 1651, the Parliament enforced regulations to control colonial commerce and restrict colonial trade to the British, thereby favouring its shipping and manufacturers.
From 1651 onwards, England instituted the Navigation Acts. All trade between the colonists and the British was to be conducted either on English vessels or on colonial-built vessels. In addition, there were certain products that could be traded only with Britain, such as tobacco, sugar and cotton. As time went on, the list of specified goods grew continually decreasing the kinds of merchandise that the colonists could sell to other nations.
As Britain was too far away to control the colonists directly, representative governments were established in the colonies The English king appointed colonial governors who had to rule in cooperation with an elected assembly. Voting was restricted to white males who owned lands.
England encouraged the colonists to specialize in the production of raw materials. English factories converted raw goods into products, which were then shipped back to the colonies. This provided the British with a profitable market, free from competition.
The Seven Years' War, also called the French and Indian War, which lasted from 1754 until 1763, was a conflict that had enormous repercussions for Great Britain. In spite of her victory over France in 1763, a royal proclamation denied the English the right to establish settlements west of the Appalachian Mountains, in order to avoid conflict with the American Indians. Moreover, with Britain's acquisition of Canada from France, the prospects of peaceful relations with the Native tribes were not good. In consequence, the British decided to keep a standing army in America. The war had also left Great Britain with a considerable national debt. The American colonists were evading trade and navigation regulations and had been trading with the French during the Seven Years’ War, so the British decided it was necessary to tighten their control and began to reform the system. The colonists, however, were creating a prosperous economy based on agriculture and trade, and no longer needed British protection.
Tensions between Britain and the colonies started when they began to charge taxes and punish smugglers. Colonial policy in the eighteenth century tried to reduce the corporate and proprietary colonies to royal colonies, which largely succeeded. In addition, the policy increased restrictions on colonial enterprise by means of laws such as the Wool Act of 1699, the White Pine Acts, the Hat Act of 1732, the Sugar Acts of 1733 and 1764, and the Iron Act of 1750.


3. ANGLO AMERICAN COLONIES

There were clear differences in the English colonies, which became "British" with the union of England and Scotland in 1707, because they were founded for different purposes, but there were also a number of common features. For instance, in every colony, political jurisdiction and issues fell within one of the three levels of government: the king and Parliament, the Colonial government, or the local government.
There were three types of British colony in North America. The first were plantation colonies. These included Virginia, North Carolina, South Carolina, and Georgia. The second group were the Middle Colonies of Maryland, Delaware, New Jersey, Pennsylvania, and New York. The third group consisted of the New England colonies of Connecticut, Massachusetts, Rhode Island, and New Hampshire. The economy of the New England colonies was based on trade in rum and slaves and on shipbuilding; the plantation colonies produced sugar, tobacco, rice, and indigo; and the Middle Colonies produced wheat and timber.

3.1. The Plantation Colonies
In the southern colonies, there was the system of slavery and black people worked on large plantations. Indentured servants were the main source of labour in the colonies. These were poor farmers who came from England and worked for a fixed period of time, from three to seven years, in exchange for their transportation, food, clothing, lodging, etc. Unlike slaves, an indentured servant was required to work only for a limited term, which was specified in a signed contract. The British tried to enslave the Indians but were unsuccessful.  The first Negro slaves arrived in Virginia in 1619.

3.1.1. Virginia

Ø      The first English colony in America was founded at Jamestown, Virginia, in 1607. The settlement was directed by the London Company, which renamed itself as the Virginia Company, was granted the authority to govern its colony.
Ø      The settlement suffered from various difficulties at first and did not prosper until the colonists received their own land and the tobacco industry began to flourish. The colony survived and, in 1614, started to ship tobacco, its main export, to England.


3.1.2. North Carolina and South Carolina
Ø      Carolina was founded with a commercial and a political purpose. The main port was Charles Town (Charleston).
Ø      The Carolina proprietors were planning to organize Carolina along the lines of a feudal state.
Ø      The colony quickly developed following the model of plantation colonies. The territory was divided up into separate plantations. The main planters had both a plantation and a second house in Charleston, where government was centralized and where they used to spend the summer months.
Ø      People of French origin soon became the elite of the new colony. They quickly adopted the English language and joined the established Church of England, but they retained an aristocratic tone that would become a distinctive feature of the colony.
Ø      In 1719, the colonists overthrew the last proprietary government, and in 1729, the king created separate royal governments in North and South Carolina. There were differences between them. South Carolina was richer, with more plantations, and was more densely populated, while North Carolina was poorer, with fewer plantations and slaves, but slightly more democratic. South Carolina’s main exports were naval supplies and rice. North Carolina’s main exports were wood, naval supplies and tobacco and

3.1.3. Georgia

Ø      In the 1730s, Georgia was the last of the colonial English settlements. It was founded with the purpose of discouraging Spanish expansion.
Ø      At first, there were few emigrants because of the restrictions that the trustees imposed, such as the restriction on the size of individual land holdings to benefit the poor. Eventually, all those restrictions disappeared and by 1751, Georgia was a slave plantation and was returned to the king.
Ø      The major exports of the colony were silk, rice, wood, and naval supplies.
Ø      One controversial issue was the fact that the trustees did not trust the colonists to make their own laws. They did not establish a representative assembly. The trustees made all laws for the colony. The trustees prohibited the import and manufacture of rum, for rum would lead to idleness. Finally, the trustees prohibited Negro slavery, for they believed that this ban would encourage the settlement of “English and Christian” people.
Ø      In Georgia's first year, 1733, all went well enough as settlers began to clear the land, build houses, and construct fortifications. Later, however,they disliked the fact that they were deprived both of any self-government and of their rights as Englishmen.


3.2. The Middle Colonies

3.2.1. New York

Ø      It was a Dutch settlement. The purpose of this foundation was commercial and its major exports were furs and grain.

3.2.2 New Jersey

Ø      New Jersey was founded with the purpose of consolidating new English territory.
Ø      They provided liberal grants of land and freedom of religion.
Ø      The major export of the colony was grain with a notable ethnic and religious diversity.

3.2.3. Pennsylvania and Delaware

Ø      In 1681, Pennsylvania (literally, “Penn’s woods) was founded with the purpose of being a refuge for English Quakers and the principal founder was William Penn.
Ø      Penn wanted to create a Holy Society and thought that both rich and poor should participate in political affairs. He guaranteed liberty of conscience and religious freedom from persecution, that a great number of peoples of different nationalities and religions poured into Philadelphia and its surroundings. The colony became ethnically very diversified with immigrants from Germany, Wales and England. The major export of the colony was grain.
Ø      The Quakers were pacifists and believed all persons possessed the spirit of God, a powerful “Inner Light” and that all persons were equal in the sight of God and everyone could be saved. They were very humble and wore very austere clothes.
Ø      The Swedes had founded the colony of Delaware in 1638, for commercial reasons. This area became part of Pennsylvania and remained so until 1703, when it created its own legislature.

3.2.4. Maryland

Ø      In 1634, Maryland was founded and established as a proprietary colony, by George Calvert, known as Lord Baltimore. He was a royalist and a Catholic who thought of this colony as a refuge for English Catholics persecuted elsewhere.
Ø      This colony was characterized by religious acceptance. The Maryland Toleration Act, also known as the Act Concerning Religion, was signed in 1649, thereby institutionalising toleration and providing impermanent protection for Catholics.
Ø      The major export of the colony was tobacco.

3.3. The New England Colonies

3.3.1. Massachusetts

Ø      English Puritans escaping religious persecution in their homeland settled in New England and founded a colony with their own religious ideals, seeking to purify the Church of England. One group of these Puritans, the so called “Pilgrims” crossed the Atlantic in the ship called the Mayflower and settled at Plymouth, Massachusetts in 1620. Before landing, they established their own government, the basis of which was the Mayflower Compact (See Document nº 1 in the Appendix. American Documents). The principal founder was William Bradford.
Ø      The original purpose of this foundation to be a refuge for English Separatists but it was also a joint-stock venture.
Ø      Landing in Cape Cod, the Pilgrims disembarked outside the authorized jurisdiction of any other English colony. They feared the rule of those who did not belong to their group, and so they drew up the Mayflower Compact. It was an agreement based on the approval of the people. It is the earliest known case in American history of people establishing a government for themselves by mutual agreement.
Ø      The first year was very hard and the colonists would not have survived the winter without help from the local Indians, the Wampanoag and the Pequamid, who shared corn with them and showed them where to fish. Later, they showed the English how to plant crops that would grow well in that soil. In 1621, the Pilgrims invited them to a feast to celebrate their survival in the harsh American wilderness, and the generosity of the Indians. That harvest feast was the first Thanksgiving.
Ø      The economy of the colony in the first years was a subsistence economy, but later it developed trade, with grain becoming the major export.
Ø      The Puritans themselves did not tolerate religious dissent in Massachusetts. They strictly punished drunks, adulterers, violators of the Sabbath and heretics. The right to vote was restricted to church members, and the salaries of ministers were paid out of tax revenues.
Ø      The economy of the Massachusetts Bay Colony was based on exporting grain and wood.



A piece of Advise (for 4ESO and"BACHILLERATO" STUDENTS): if you can, download these films:
The Crucible, 1996. Actors: Wynona Ryder, Daniel Day Lewis. (It’ about Salem witch trials).
The Scarlet Letter, 1995, Actors: Robert Duvall, Gary Oldman, Demi Moore.
Both films show how hard was to live in a Puritan environment.



3.3.2. Connecticut

Ø      A group of Puritans from Plymouth established a settlement. The first permanent settlement made in the valley of the Connecticut River was created by Puritans from Massachusetts circa 1635.
Ø      The major export of the colony was grain.

3.3.3. Rhode Island

Ø      Rhode Island was founded by squatters. Puritans who protested that the state should not interfere with religion, were forced to leave Massachusetts Bay.
Ø      Here they advocated freedom of religion and clear separation of church and state, They also recognized Indian land rights and negotiated with the Indians. As a result, Rhode Island became a refuge for dissenters from Massachusetts.

3.3.4. New Hampshire


In 1622, the Plymouth Company granted land in northern New England between the Merrimac Kennebec, and St. Lawrence Rivers to John Mason and to Sir Ferdinando Gorges. Mason eventually founded New Hampshire and Gorges’ land led to Maine. Massachusetts controlled both until New Hampshire was given a royal charter in 1679 and Maine was made its own state in 1820.



The 13 Colonies in 1775
This map shows the 13 British colonies in North America as they existed on the eve of the American Revolution (1775-1783). After winning independence from Britain, the colonies made up the first 13 states of the newly formed United States of America.




THE MOLE

The Mole

Simply put, the mole represents a number. Just as the term dozen refers to the number twelve, the mole represents the number 6.02 x 1023.
Now that's a big number! While a dozen eggs will make a nice omelet, a mole of eggs will fill all of the oceans on earth more than 30 million times over.
The mole is used when we're talking about numbers of atoms and molecules. Atoms and molecules are very tiny things. A drop of water the size of the period at the end of this sentence would contain 10 trillion water molecules. Instead of talking about trillions and quadrillions of molecules (and more), it's much simpler to use the mole.

History of the Mole

The number of objects in one mole, that is, 6.02 x 1023, is commonly referred to as Avogadro´s number. Amadeo Avogadro was an Italian physics professor who proposed in 1811 that equal volumes of different gases at the same temperature contain equal numbers of molecules About fifty years later, an Italian scientist named Stanislao Cannizzaro used Avogadro's hypothesis to develop a set of atomic weights for the known elements by comparing the masses of equal volumes of gas. Building on this work, an Austrian high school teacher named
Johann Josef Loschmidt calculated the size of a molecule of air in 1865, and thus developed an estimate for the number of molecules in a given volume of air. While these early estimates have since been refined, they led to the concept of the mole - that is, the theory that in a defined mass of an element (its atomic weight) there is a precise number of atoms: Avogadro's number.

Molar Mass

A sample of any element with a mass equal to that element's atomic weight (in grams) will contain precisely one mole of atoms (6.02 x 1023 atoms).  For example, helium has an atomic weight of 4.00.  Therefore, 4.00 grams of helium will contain one mole of helium atoms.  You can also work with fractions (or multiples) of moles:  

Mole/Weight Relationship Examples Using Helium
Moles Helium
 Helium Atoms
Grams Helium
1/4
1.505 x 1023
1 g
1/2
3.01 x 1023
2 g
1
6.02 x 1023
4 g
2
1.204 x 1024
8 g
10
6.02 x 1024
40 g

Other atomic weights are listed on the periodic table. For each listed, measuring out a quantity of the element equal to its atomic weight in grams will yield 6.02 x 1023 atoms of that element.
The atomic weight of an element identifies both the mass of one mole of that element and the total number of protons and neutrons in an atom of that element. How can that be? Let's look at hydrogen. One mole of hydrogen atoms will weigh 1.01 grams.
Each hydrogen atom consists of one proton surrounded by one electron. But remember, the electron weighs so little that it does not contribute much to an atom's weight. Ignoring the weight of hydrogen's electrons, we can say that one mole of protons (H nuclei) weighs approximately one gram. Since protons and neutrons have about the same mass, a mole of either of these particles will weigh about one gram. For example, in one mole of helium, there are two moles of protons and two moles of neutrons - four grams of particles.

Molecular Weight

If you stand on a scale with a friend, the scale will register the combined weight of both you and your friend.  When atoms form molecules, the atoms bond together, and the molecule's weight is the combined weight of all of its parts.
For example, every water molecule (H2O) has two atoms of hydrogen and one atom of oxygen.  One mole of water molecules will contain two moles of hydrogen and one mole of oxygen.  
  
A bottle filled with exactly 18.02 g water will contain 6.02 x 1023 water molecules. The concept of fractions and multiples described above also applies to molecules: 9.01 g of water would contain 1/2 mole, or 3.01 x 1023 molecules.  You can calculate the molecular weight of any compound simply by summing the weights of atoms that make up that compound. 
Molecular Weight Calculator