Solar cells Essay Example for Free

Solar cells Essay I am trying to find out how the current changes with the area of the solar cells. THEORY The energy in light can be transformed into electricity when shone onto semiconductor materials. Silicon and germanium normally have electrons in low energy states. Absorption of light excites these electrons into higher states and generates a voltage (typically 0. 5 V per cell). As more light is absorbed, more electrons are excited and the current supplied increases. The energy of the photons transfer to electrons in the semiconductor. The energized electrons then break free for the silicon atoms and transfer them to an electric circuit. If we completely cover the top of a solar panel then, then photons cannot get through the conductor, and the current is lost. Internal Resistance (called series resistance) if this is high then this means high losses, to minimize the losses; the cell is covered by a metallic contact grid that shortens the distance that electrons have to travel. FAIR TESTING In this experiment I will only change 1 factor, which is the area of solar cell. I would have to change the card placements which I will use to cover the solar cell at the same measurements every time. I will change the length of the card each time from 100%, 75%, 50% and 25%. The following factors that are going to be kept constant are:- 1. The distance from the lamp to the solar cell if this is changed it will affect the number of photons hitting the solar cell for each reading. 2. The positioning of the lamp if this is changed; it could also affect the number of photons hitting the solar cell for each reading. The lamps must point at the solar panel only. 3. The time this, would have to be accurate i. e. not leave the solar panel under the lamp for too long or it could affect the temperature and the intensity of the light producing photons on the solar cell. The light source The intensity of the light source will be kept the same to prevent more or less photons hitting the solar cell for each reading. 5. The bulb watt this would have to be kept constant, i. e. if I use double the watt of the bulb that double the photons will hit the solar cell. 6. The card If this is change, than this could affect the number if photons which hit the solar cell. PREDICTION Using my scientific knowledge and preliminary research I predict as the percentage area uncovered increases; more photons will hit the semi conduct device, meaning more electrons will be released resulting in more electric current.

Happy Essay -- essays papers

Happy Middle East History Jerusalem The conflict in Jerusalem is rooted in religious, political, and historical aspects. As a center for the worlds three major religions, with a history of political divisions and borders, as well as historical claims to the territory, it calls for a peaceful coexistence and sensitive diplomacy which will enable an accepted agreement. Jerusalem is a prize which, for thousands of years, has been fought over. Israeli’s and Palestinians live side-by-side in the Old City, each claiming that Jerusalem belongs to them. There is no judgment that can be given, there is no right or wrong answer to the problem. For this issue to be solved, both sides must give concessions to each other, and truly feel the need for peace and friendly diplomacy in Jerusalem. The Torah, the most sacred Jewish text, claims that Jerusalem is the ancestral home of the Jewish people. The Torah says that the land was given to Abraham, the Jews patriarch, and his descendent as a birthright for his faithfulness to God. In 1000 BC, David, the Jewish king, established Jerusalem as his capital, and his son, Solomon, built a temple in the city for the Jewish people. Four centuries later, the Jews were conquered and forced into exile. They would not return to Jerusalem until the founding of modern Israel in 1948. During the Roman occupation of Palestine, Jesus was born in the city of Bethlehem. For Christians, Jesus is the Son of God, and the Messiah. Because of his religious beliefs, he as crucified near Jerusalem, and three days later, was resurrected. Tradition holds that the tomb was where the Church of the Holy Sepulcher is today. The Holy Land gave birth to the faith of Christianity. Shortly after the death of Mohammed, the man who established Islam and whom Muslims believe to be the prophet of Allah, the Muslims conquered Jerusalem. Muslims, too, claimed a rightful ownership of the land. They believe that they have an inheritance connection to the patriarch, Abraham, through a different lineage. Jerusalem holds incredible religious significance for the Muslims. Ten years before his death, Mohammed traveled to Jerusalem, where he then rose to heaven to speak with Allah directly. The Muslim people built the Dome of the Rock on top of the Temple Mount in honor of Mohammed’s journey to the heavens. The Dome of the Rock is considered t... ...rcede in this problem as violence and hatred increases. Israel’s use of excessive force against the Palestinians, and the violent attacks against Israeli’s by the Palestinians is only making matters worse. UN Secretary General, Kofi Annan, has convinced Arafat and Barak to meet and come to some sort of peace agreement. The conflict centers mainly around religious claims and political issues. Both sides feel that Jerusalem is rightfully theirs because of its historical religious connections to their religions. The political action taken for the control of the city has had strong moments, but has also faltered. It is as if the process takes one step forward and two steps backward with each time a small conflict arises. Both sides must give in something in order to achieve peace. The Palestinian people have nothing, and their only hope for a future of some sort is to create a Palestinian state. Israel, however, does not want to give up their â€Å"capital† and will do anything in their power to maintain their control over it. The United Nations must intervene, as it is the â€Å"voice of the world,† and will be able to help Arafat and Barak reach a consensus on the status of Jerusalem.

Compare the Ways

To highlight this attention has to be given to the story and roots of youth work in England. One of the first types of youth work provision was the early network of Sunday Schools founded by Robert Raises and Hannah Moore in 1780. Their idea was to morally educate the children and young people of the working classes because at this time less than a third of children of school age actually attended school; hence the young population, especially females, were uneducated (Smith, Bibb).However the working class attempted to create bottom-up forms of education themselves with the formation of the Young Man's Christian Association in 1844 by George Williams. Within the association were the early characteristics of a youth work approach and an emphasis on healthy spiritual well-being especially for city dwelling young males (Smith, AAA; Smith, Bibb).This reflects the morally upright and patriarchal Victorian views of the time along with the recognition of youth as a discipline in its own ri ght (Staunton Rogers, 2004). By the mid nineteenth century the struggles of the working class had been all but lost with the influx of top-down institutions which were mainly church led. Toward the end of the century young sections of the population were identified as needing activities to engage in to improve their leisure time and to maintain social control.It was widely accepted that this leadership would be undertaken by a range of philanthropic institutions and state run establishments. One of the most significant youth organizations of this period was the Scouting movement started by Robert Baden-Powell. To accentuate the importance of state social control and the Liberalism's political agenda school attendance became compulsory up to the age of ten with the introduction of the 1880 and 1902 Education Acts (Smith, AAA).It was also around this time and Britain's early globalization and the changing social and economic conditions that prompted the Politician's and educated membe rs of society to develop country wide youth practice as observers believed that the youth of English nation were experience new and harsh encounters and a lot of this was to do with the newly constructed phase of adolescence, this new breed of child needed discipline , protection and some nurturing(Davies,1967).As Russell and Rugby commented â€Å"some of the challenges were domestic. As the demand for unskilled especially child) labor reduced more and more young people were neither in school nor work† they felt that the young adolescence leisure time was not being fulfilled and the young â€Å"indulge in ‘one main amusement gambling (Russell & Rugby, 1908: 10-11). D The youth of the country were seen as being tested, too, within a new international context who should, who could, take on these emerging responsibilities?Pragmatic and often major compromises with the laissez-fairer principles which had so shaped Victorian Britain had already been made – in order f or example to errant public health and spread elementary education to the whole population. Nonetheless, in this later nineteenth century period and even into the early decades of the twentieth century the state remained, at best, an unwelcome intruder into the personal and social spheres of people's lives. For responding to the newly identified leisure-time needs of young people, a state role was therefore never apparently considered.Self-evidently, these were suitable fields for voluntarily supported clubs' (Berry, 1919: 96) – a task for thinking people who felt something must be done†¦ (Russell and Rugby, 1908: 12); for those who were conscious of what their ‘happier fortune has bestowed on us from our circumstances' (Button, 1985: 14); who were fortunately placed' and therefore felt very strongly that in some way (action) was incumbent on us' (Chill, 1935: 5). By the early decades of the twentieth century the result was a network of local independent boys and g irls clubs across the I-J.From the sass, under the influence of William Smith, military-style brigades for boys and girls also took hold and by the sass were being supplemented and indeed often underpinned by Baden Bowel's Boy Scouts and later the Girl Guides. In due course these sought mutually supportive links by setting up a range of local, regional and national associations and federations. The Boer War highlighted the need for a fitter, healthier generation of young men and this was supported by social research (Staunton Rogers, 2004).In response to these findings the Children Act 1908 was introduced to establish a Juvenile Justice system, specific medical treatment and free school meals specifically for minors. However, despite young people during this period beginning to be recognized in heir own right there was an ulterior political and philanthropic agenda to enforce social control and Christian morals for both girls and boys (Staunton Rogers, 2004). Nevertheless society be gan to change during World War One as young men were conscripted into the horrors of war and returned transformed.Whereas women were no longer perceived as, â€Å"delicate maidens of Victorian sensibilities† but instead began to be recognized as capable individuals with their own identities (Staunton Rogers, 2004: 4). Subsequently it was recognized that state intervention was needed ND powers and funding were given to local authorities to invest in Juvenile Organizing Committees (Smith, AAA). Up until this point it was still normal to talk about work with or among boys and girls (or young men and women or youth).In the late sass we see the growing use of the term ‘youth work'. The first booklet in the UK appeared with it in its title: Methods in Youth Work (Walked et al 1931). Bibliography Davies, B. And Gibson, A. (1967). The social education of the adolescent, London: University of London Press. IPPP. Laudable, J. (1989) ‘Children in history: concepts of nature and society In: Scarce, G. Deed) Children, Parents and Politics. Cambridge: Cambridge University Press. IPPP-20. Russell, C. E. B. And Rugby, L. M. 1908, Working Lads Clubs, London, MacMillan and Co Ltd. Smith, M. K. (AAA) Youth Work an Introduction. Http://www. Infer. Org/youth's/b-WY. HTML [accessed 08. 11. 12]. Smith, M. K. (Bibb) ‘Hannah More: Sunday schools, education and youth work' The Encyclopedia of Informal Education. Http://www. Infer. Org/thinkers/more. HTML [accessed 9. 11. 12]. Poverty was abundant and with the start of the industrial revolution it was inevitable that children were used as cheap labor (Laudable,1989. Smith, 2002).

Gay Theatre A Microcosm Of The Contemporary Homosexual...

Gay Theatre: A Microcosm of the Contemporary Homosexual Landscape When you hear the term ‘gay theatre’ the first thought that may come to mind is that it describes theatre written for and by homosexuals. If this is true, then before the decriminalization of male homosexual sex in 1967, there was no ‘gay theatre’ in existence due to the political and social landscape of that time. Spanning as far back as Christopher Marlowe and William Shakespeare, themes of homosexuality have been rampant within theatrical content, but because theatre always reflects the social conditions of its time period, the theatre’s behavior toward homosexuality was a microcosm of its contemporary governing attitudes. Before the 1960s, theatre was subject to†¦show more content†¦In the 1920s, being gay in the United States and Great Britain was a crime, illness, and a sin, and it was depicted, as such, on the stage. In much of the theatrical content of the time, the homosexual character was portrayed as very effeminate, pitiful an d sinister. In 1737, an act of Parliament in Britain orchestrated that all licensing and censorship of plays were to be subject to the transgression of the Lord Chamberlain, and similarly in New York, stage legislature outlawed anything that dealt with ‘sexual perversion’. Because of this, homosexuality was not even discussed outwardly on stage until 1958. With this censorship in place, theatre had to be very oblique when dealing with homosexual content. For example, in 1924, Noel Coward’s play The Vortex included a character with an intense cocaine habit that was a metaphor for his repressed homosexuality. Even in metaphor, we are given a very dark, self-loathing view of homosexually that is most likely a product of Coward’s own existence as a closeted homosexual. Oscar Wilde, the most famously homosexual playwright of the time, never wrote a single gay character, but instead expressed his sexual deviance through other kinds of social relations with in his writing. Critics have said A Picture of