Bridge damage

Every year, many types of failures affect structures as a result of hydraulic action. In fact, hydraulic damage is unpredictable, so protecting bridges from this type of damage is essential. Every year, a huge sum of money and a lot of time are spent in repairing bridges because of hydraulic damages. In the past two decades, the quick deterioration of bridge structures has become a serious technical and economical problem in a lot of countries especially in highly developed ones. A better way to prevent these additional expenditures is by protecting bridges from this type of damage through correct design and construction.The purpose of this study is to summarise information about hydraulic damage and identify various methods of bridge pier design and construction that might help prevent hydraulic damage. The study also examined various causes of bridge failure due to hydraulic damage and tried to determine factors such as what would be the best shape for the bridge to avoid hydraulic damage, the most useful types of materials for constructing bridges, and the methods of construction most conducive to protecting bridge piers from this type of damage.The study aims to explain the factors that affect hydraulic damage resulting in bridge failure and come up with clear type methods to protect bridge piers from hydraulic damage. Generally, the loss of pier stability results more from the subsoil factors rather than force factor. This section reassesses the types of failures that may happen to bridges as a result of Hydraulic action and it can be divided into five major categories, namely, Scouring, Bank Erosion, Hydraulic forces on piers, Failure due to ice forces, and Failure due to debris.Scouring is one of the most common causes of hydraulic damage and it is estimated that nearly 60% of all failed bridges failed because of this. When the speed of flowing water is more than it should be, it may reduce the bed level by excavating and removing the bed materials and m aking large holes around the piers that gradually cause bridge failure. Local scour removes bed material from around the piers and abutments, also at bridge piers. The effect is usually greatest near the upstream nose of the piers, which may lead to the pier being damaged first at the upstream end and thus sloping.Geometric parameters are important in the estimation of localised scour, including degree of flow contraction caused by the bridge restricting the flow area, and foundation geometry. The geometry of piers can be illustrated by the shape, length, width and alignment with the flow of individual piers. Bank erosion and channel migration are other factors; several rivers tend to change their route with time. A bridge that is located to suit one location of the main channel may become progressively at risk to scour failure as the river changes.Abutments or piers placed on the original floodplain, if not designed to accommodate channel migration, may be undermined or otherwise w eakened if this occurs. Protection repairs involving the placing of rock guard around bridge piers can reduce the flow area of the main span and direct to flow being diverted on the way to other channels. For example, a river with a sharp longitudinal gradient and high flowing velocity will be more prone to bank erosion than a flat slope river with low velocity.Flowing water (Hydraulic Force) applies force on bridge piers. One such force works alongside the route of flow, and is referred to as drag force. The other force is typically applied to the direction of flow, and is referred to as lift force. If the flow aligns with a pier and has a lift force equal to zero, the capacity of the pier to withstand lift and drag forces might be reduced during a flood if scouring also occurred around the base of the pier. Debris has an effect on hydraulic acts of bridge performance.Debris can limit flow leading to significant scour levels around piers. Assembled debris can negatively impact the passageway under a bridge by increasing the hydraulic load on the bridge and this can also affect the hydrostatic forces which may cause structural failure. Ice can also inflict forces against structures due to its extension during freezing, but this appears improbable in the fluvial location. The impact of sheets of ice on the piers probably is the greater risk.Crushing is a common type of ice failure as it results in high forces or loads on a bridge pier. The main cause of bridges failure due to hydraulic damages is scour. Several methods are available to protect bridge piers from hydraulic damages, however the first step of pier design is estimating the depth of scour, but it is recommended that the overall design should involve the calculation of afflux, depth of scour and various type of hydraulic loads. Scour protection measures should also be considered during the designing process.Generally, the methods relevant to both the piers and the abutments can be classified into two most important groups, namely: methods consisting of strengthening the subsoil and methods consisting of strengthening the foundations. Foundation of bridge piers on floodplains should be placed at the same depth as the piers foundation in the stream channel. Also, streamline pier shapes helps to reduce scour and minimise the potential of debris build up. Many types of bed materials scour at different rates but loose granular soils have lower resistance to scour.Scour in sand bed stream will be as deep as scour in cohesive or cemented soils. Scour will achieve its highest depth in sand and gravel bed materials in hours, cohesive material in days, limestone in years and dense granites in centuries. Massive rock configuration is highly anti-scour during the lifetime of a typical bridge. In different types of foundations, especially piled foundations, using less significant number of long piles to extend bearing resistance will provide greater resistance to pile failure due to scour co mpared to shorter piles.The top of the pile cap should be placed at a depth below the existing river bed level and at the same level as estimated general scour depth. Stone aprons (Riprap) are situated around piers and abutments as a flexible way to avoid local scour development; the specific parameter that should be considered here is using a large enough stone because it should remain stable under maximum velocities. Also, the stone should be located in a pre-excavated position beneath the bed of the river so the velocities are not increased by its existence.Constructing bridge piers deep enough to avoid this requires a riprap. This means that while increasing the depth of the pier’s and abutments’ foundation from the bed surface, it becomes more efficient in withstanding a high velocity of flood flow. Another thing to be considered is supplying a roadway that comes close to the profile so it will be overtopped before the submergence of the bridge superstructure. Thi s is useful in reducing scour at the bridge piers. Another method of preventing hydraulic damage is through a process called Enlargements.Enlarging the base of piers may limit the depth of local scour. Additional protection method is positioned at the bridge pier foundation on floodplains and it should be at the same depth as the pier foundation in the stream channel because there is uncertainty in predicting the level of scour. Using extreme limitations in foundation design if there is any likelihood that the channel will shift its location onto the floodplain over the life of the bridge is a good policy.There are many more types of bed and bank protection including gabions and gabion mattresses and proprietary systems of interlocking blocks, alteration of a pier’s nosing shape and provision of piles of a smaller diameter than the width of the pier. The benefit of a stone protective covering layer, roughly the nose of a pier, is easy to situate and it does not need any exten sive dewatering or diversion work. However, it is not always cost effective The Oreti River Road Bridge is a two lane-bridge built in 1995. It holds Highway 99 crossways. It involves 20 spans of 12 m.with eight spans which are placed over the main channel and each pier was designed with two rows of six 7. 6 m. driven RC piles; largest size of bed materials has been reduced by 100mm to 50mm at present. In 1975, scour occurred and four central piles in each group of 12 gone from 5 of the piers and survey shows that scour bed level was 1 to 5 m. below the scour depth that was predicted. To repair damage, they put protective rocks below the bridge with a top elevation of 1. 7 m. beneath the underside of pile caps and they built a rock weir about 60 m. downstream of the bridge.

Roman Education

Essay 1 The question at hand is â€Å"According to ancient Greek rulers, historians and philosophers, what role should education and property/wealth play in determining who should govern? † In order to answer this question you must look into the very core of Greek society. To learn about Greek society I have read readings from ancient Greek historians and philosophers such as Aristotle, Plato, Socrates, and Thucydides. Plato introduced Greece to the thought of Idealism and his take on what an ideal society looks like. Aristotle believed that the way a household is ran correlates to society as a whole.Greece believed in democracy, therefore a household should be run in accordance to idealistic, democratic views. The ruler of the house, the man, has more control than the women, the women more than the slaves, and the children have no control but are considered above slaves. Aristotle thinks a man’s wealth is not always considered by his property value but by his knowledge . He said â€Å"†¦it is clear then that in household management the people are of greater importance than the material property, and their quality of more account than that of goods that make up their wealth. (Aristotle) Greek philosophers believed that in order to become a ruler you must have standards throughout your life. Aristotle said â€Å"†¦for neither life itself nor the good life is possible without a certain minimum standard of wealth. Again, for any given craft the existence of the proper tools will be the essential for the performance of its task. † Aristotle is saying that any ruler must have grown up with standards. A child’s knowledge is only as good as who is raising the child, therefore a ruler must have grown up under people who have high standards of society living.This can point us in the direction of rulers handing the throne down to sons or other family members. It seems logical to think that a person that has grown up under the supervi sion of a ruler would carry the same beliefs and ethics about society and life in Greece. This is further explained in a quote from Aristotle â€Å"Take the child: he is not yet fully developed and his function is to grow up, so we cannot speak of his virtue as belonging absolutely to him, but only in relation to the progress of his development and to whoever is in charge of him. †With power comes wealth, and wealth is very important when it comes to being a ruler that can have things done. Thucydides said â€Å"we employ wealth for use than for show. †(Thucydides) That statement alone gives way to the thought that wealth can buy you anything, even leadership. Of course Greek people believe in idealism and want their leader to be pure and believe in all their virtues. That does not mean that money cannot get you power, because it certainly does still to this day. Plato believes in more than just wealth and property. He believes in the pureness of one’s soul and their virtues.He said â€Å"†¦and they will have to watched at a very young age, in order that we may see whether they preserve their resolution, and never, under the influence and force of enchantment, forget or cast off their sense of duty to the state.. †(Plato) This is Plato’s idea of true knowledge, the thought of a soul that has a clear thought of how to rule a society. When it comes down to it knowledge is more important in picking a ruler, but wealth plays a bigger role in placing a person in the position of getting picked. The Greek philosophers agree that knowledge of idealistic beliefs is more important idealistically in picking a ruler.

Pepsico Diversification Essay

PepsiCo’s Diversification Strategy in 2008 PepsiCo was the world’s largest snack and beverage company, with 2007 net revenues of approximately $39. 5 billion. The company’s portfolio of businesses in 2008 included Frito-Lay salty snacks, Quaker Chewy granola bars, Pepsi soft drink products, Tropicana orange juice, Lipton Brisk tea, Gatorade, Propel, SoBe, Quaker Oatmeal, Cap’n Crunch, Aquafina, Rice-A-Roni, Aunt Jemima pancake mix, and many other regularly consumed products. Company History PepsiCo Inc. was established in 1965 when Pepsi-Cola and Frito-Lay shareholders agreed to a merger between the salty snack icon and soft drink giant. The new company was founded with annual revenues of $510 million and such well-known brands as Pepsi-Cola, Mountain Dew, Fritos, Lay’s, Cheetos, Ruffles, and Rold Gold. PepsiCo’s roots can be traced to 1898 when New Bern, North Carolina, pharmacist Caleb Bradham created the formula for a carbonated beverage he named Pepsi-Cola. The company’s salty-snack business began in 1932 when Elmer Doolin of San Antonio, Texas, began manufacturing and marketing Fritos corn chips and Herman Lay started started a potato chip distribution business in Nashville, Tennessee. In 1961, Doolin and Lay agreed to a merger between their businesses to establish the Frito-Lay Company. There are also so many other products and companies that merger with PepsiCo throughout the years. Once Quaker Oats’ food, snack and beverage brand merged with PepsiCo companies in the United States and internationally broadened it portfolio of the brands. Internationally Pepsi brought countries like the Netherlands, Poland, Ukraine, Bulgaria, Brazil and Canada. Marketing From the 1930s through the late ’50s, â€Å"Pepsi-Cola Hits The Spot† was the most commonly used slogan in the days of old radio, classic motion pictures, and later television. Its jingle (conceived in the days when Pepsi cost only five cents) was used in many different forms with different lyrics. With the rise of television, Pepsi utilized the services of a young, up-and-coming actress named Polly Bergento promote products, oftentimes lending her singing talents to the classic â€Å"†¦ Hits The Spot† jingle. Some of these Bergen spots can be seen on ClassicTVAds. com. Through the intervening decades, there have been many different Pepsi theme songs sung on television by a variety of artists, from Joanie Summersto The Jacksonsto Britney Spears. See Slogans) In 1975, Pepsi introduced the Pepsi Challengemarketing campaign where PepsiCo set up a blind tasting between Pepsi-Cola and rival Coca-Cola. During these blind taste tests the majority of participants picked Pepsi as the better tasting of the two soft drinks. PepsiCo took great advantage of the campaign with television commercialsreporting the results to the public. In late 2008, Pepsi overh auled their entire brand, simultaneously introducing a new logo and a minimalistlabel design. The redesign was comparable to Coca-Cola’s earlier simplification of their can and bottle designs. Also in 2008 Pepsi teamed up with Google/YouTube to produce the first daily entertainment show on Youtube, Poptub. This daily show deals with pop culture, internet viral videos, and celebrity gossip. Poptub is updated daily from Pepsi. In 2009, â€Å"Bring Home the Cup,† changed to â€Å"Team Up and Bring Home the Cup. † The new installment of the campaign asks for team involvement and an advocate to submit content on behalf of their team for the chance to have the Stanley Cupdelivered to the team’s hometown by Mark Messier. Pepsi has official sponsorship deals with three of the four major North American professional sports leagues: the National Football League, National Hockey Leagueand Major League Baseball. Pepsi also sponsors Major League Soccer. Pepsi also has sponsorship deals in international cricketteams. The Pakistan cricket teamis one of the teams that the brand sponsors. The team wears the Pepsi logo on the front of their test and ODI test match clothing. On July 6, 2009, Pepsi announced it would make a $1 billion investment in Russia over three years, bringing the total Pepsi investment in the country to $4 billion. In July 2009, Shag-me started marketing itself as Pepsi in Argentinain response to its name being mispronounced by 25% of the population and as a way to connect more with all of the population. In October 2008, Pepsi announced that it would be redesigning its logo and re-branding many of its products by early 2009. In 2009, Pepsi, Diet Pepsiand Pepsi Maxbegan using all lower-case fonts for name brands, and Diet Pepsi Max was re-branded as Pepsi Max. The brand’s blue and red globe trademarkbecame a series of â€Å"smiles,† with the central white band arcing at different angles depending on the product until 2010. Pepsi released this logo in U. S. in late 2008, and later it was released in 2009 in Canada(the first country outside of the United States for Pepsi’s new logo), Brazil, Bolivia, Guatemala, Nicaragua, Honduras, El Salvador, Colombia, Argentina, Puerto Rico, Costa Rica, Panama, Chile, Dominican Republic, the Philippines and Australia; in the rest of the world the new logo has been released in 2010, meaning the old logo has been phased out entirely (most recently, Franceand Mexicoswitched to Pepsi’s current logo). The UK started to use the new Pepsi logo on cans in an order different from the US can. In mid-2010, all Pepsi variants, regular, diet, and Pepsi Max, have started using only the medium-sized â€Å"smile† Pepsi Globe. Pepsi and Pepsi Max cans and bottles in Australia now carry the localized version of the new Pepsi Logo. The word Pepsi and the logo are in the new style, while the word â€Å"Max† is still in the previous style. Pepsi Wild Cherryfinally received the 2008 Pepsi design in March 2010. PepsiCo and it’s THREAT According to Consumer Reports, in the 1970s, the rivalry continued to heat up the market. Pepsi conducted blind taste testsin stores, in what was called the â€Å"Pepsi Challenge†. These tests suggested that more consumers preferred the taste of Pepsi (which is believed to have more lemonoil, less orangeoil, and uses vanillinrather than vanilla) to Coke. The sales of Pepsi started to climb, and Pepsi kicked off the â€Å"Challenge† across the nation. This became known as the â€Å"Cola Wars†. In 1985, The Coca-Cola Company, amid much publicity, changed its formula. The theory has been advanced that New Coke, as the reformulated drink came to be known, was invented specifically in response to the Pepsi Challenge. However, a consumer backlash led to Coca-Cola quickly reintroducing the original formula as Coke â€Å"Classic†. According to Beverage Digest’2008 report on carbonated soft drinks, PepsiCo’s U. S. market share is 30. 8 percent, while The Coca-Cola Company’s is 42. 7 percent. Coca-Cola outsells Pepsi in most parts of the U. S. , notable exceptions being central Appalachia, North Dakota, and Utah. In the city of Buffalo, New York, Pepsi outsells Coca-Cola by a two-to-one margin. Overall, Coca-Cola continues to outsell Pepsi in almost all areas of the world. However, exceptions include India; Saudi Arabia; Pakistan(Pepsi has been a dominant sponsor of the Pakistan cricket teamsince the 1990s); the Dominican Republic; Guatemalathe Canadian provincesof Quebec, Newfoundland and Labrador, Nova Scotia, and Prince Edward Island; and Northern Ontario.

Globalization and Inequality in Developing Nations Annotated Bibliography

Globalization and Inequality in Developing Nations - Annotated Bibliography Example The final research paper will have several sections in it that will analyze different aspects of globalization as it has affected and affects the developing nations all over the world and specifically investigate how such aspects have contributed to inequality in developing nations. This paper will be investigative and educative in the sense that it will discuss the globalization effects in developing nations, both positive and negative and how they have contributed to inequalities in developing nations and make recommendations on how developing nations can use this information to ensure that globalization provides more benefits than challenges for them by reducing inequalities within their population.First, the research paper will give a summary of globalization and how it came to be generally and in developing nations. Here, the research paper will seek to give the reader general information on the topic.In discussing the effects of globalization in developing nations, the paper wi ll start by discussing the positive effects of globalization in developing nations and how inequalities came about. Here, the paper will seek to provide the reader with information regarding the manner in which globalization has contributed to growth and betterment of lives in developing nations over time and how this has led to inequalities within the developing nations. To do this, the research paper will discuss different ways through which globalization has positively affected developing nations and the inequalities from these.

Fundraise to cure Autism Essay Example | Topics and Well Written Essays - 500 words

Fundraise to cure Autism - Essay Example Some of the explanations for the occurrence of autism are explained by the presence of heavy metal in the environment and pesticides or the vaccines given at child hood. The later lacks scientific proof and do not hold any fact. The prevalence of autism is said to have assumed an upward trend and for every 1,000 births in the US, 11 are diagnosed with autism-courtesy of the Centre for Disease Control (Belli, 24). With reference to autism, most of the children who are diagnosed cannot be given proper management of the disease for recovery due to their parent inability to pay for the cost of the management. Autism is not given direct medication; it is a collection of psychosocial intervention to give remedies in this situation, which includes; occupational therapy, language and speech therapy, structured teaching, and social skills among other (Struat,2011). The specialist who can offer the management of the condition needs payment, which may not be forthcoming to most of the parent. In a bid to show solidarity with the affected families, I call for a fundraising to help the families foot the bills for the medication purpose. I believe that through fundraising we are able to constitute a significant pool of resources that will enable us take care of the situation in helping our nation not to have generation that are not socially active. The fund raising is not stipulating any specific amount but will be a way of joining hands to realize a specific goals where individuals would have not made it. I therefore appeal the entire public to purpose contributing towards eradication of the condition amidst us. The two pictures displayed below shows the effect of the condition to a child who has not been given any attention in the management of the condition and one who has been attended to. This will help you understand the seriousness of the condition if left unattended (Randolph, 2012). Issues involving fundraising

Scientific Uncertainty Web-Based Assignment Example | Topics and Well Written Essays - 750 words

Scientific Uncertainty Web-Based - Assignment Example He is concurrently vice chairman of the International Academy of Education (The Heartland Institute, 2012b). Its stated mission is the discovery, development, and promotion of social and economic solutions to problems based on free-market economics (The Heartland Institute, 2012c). It is a fierce skeptic of global warming. Their agenda seems non-partisan, but the ties of the leader suggest being pro-big business, as a prominent Republican. Consequently its values are those of the conservatives (The Heartland Institute, 2012; University of Illinois, 2012). NASA is a global warming proponent and posits that human activities are at the core of recent unprecedented trends towards warming with consequences to humans and the ecology. It is a government entity receiving funding from the current Democratic leadership. Its agenda cum mission is implied in its stand: to present mainstream scientific data on climate change. Its values are nonpartisan, science-based, and arguably tinged with Dem ocratic principles owing from the Democratic leadership (NASA, 2012). Skeptical Science has as its mission essentially the advancing of climate change arguments and the debunking of arguments against climate change science by deniers and skeptics of climate change. It has support from a wide stratum of scientists and academicians with nonpartisan interests throughout the world, and is a repository of data and articles that support its implied mission. Its values seem to include openness, diversity, and inclusion of all available data, without prejudice, and with no funding or overt agenda other than the truth (Cook, 2012). 2. Key Evidence Presented by Websites on Ice Melt and Climate Change, Stated Evidence Sources Skeptical Science updates evidence and data about climate change routinely, coming from contributors who are scientists and academics from all over the world. Examples include experiments on computer modeling relating to the way the permafrosts are being thawed due to cli mate change, citing prior research by reputable scientists published in Nature GeoScience in 2012. Another example details results of studies on climate change with data inputs from African data sampling expeditions, as well as other permafrost melting studies, all referenced and published in reputable scholarly journals (Cook, 2012). NASA likewise cites evidence from scholarly sources, including from the National Research Council, the UNSW Climate Change Research Center in Sydney, the journal Science, and the IPCC. For instance, evidence with regard to man-made global warming and the fast pace of its acceleration over the last 1,300 years are documented and presented in the NASA site, complete with graphical presentations of CO2 emissions over the past 650,000 years, and properly referenced from an IPCC report. Ice core research confirming global warming trends were attributed and visibly cited from a 2006 research study by the National Research Council (NASA, 2012). The Heartland Institute in turn presents data that refute ice melt and global climate change, coming from sources reportedly from the US Energy Information Administration, among others. (The Heartland Institute, 2012). One paper presented as an article containing arguments against the reality of global warming meanwhile, from the Heartland Insti

Housing discrimination of new immigrants in Toronto and Ontario Research Paper

Housing discrimination of new immigrants in Toronto and Ontario - Research Paper Example As many immigrants would say, racial discrimination is a fact that ills many societies and is not only a problem in Canada. In essence, minorities attract ratings according to their racial origin, religious background, ethnic language, and their sources of income influenced their living conditions (Patrias, Savage & CCLH, 2012). This tends to be a matter that is of exceptional human concern as discrimination of any kind is against the human rights provisions (OHRC, 2007). Often, immigrants tend to be last in the consideration list for possible occupancy in residential areas resided by those who are economically able in society. However, the grimiest housing blocks play host to immigrants who have poor economic background in Toronto and Ontario. This happens irrespective of the education level of an immigrant but because of their skin tones that make them appear unable. Is discrimination according to ones race justifiable in determining whether one can have decent living conditions? T herefore, this essay will delve on the housing challenges that new immigrants encounter in Ontario and Toronto. Background and current status Ideally, racial prejudice arose mainly because of international slavery that saw millions of minority racial groupings move to the western nations. In essence, slave trade in the early centuries was a trade that many viewed as contravening to human nature principles. Subsequently, slaves increased in numbers making their descendants remain in the foreign lands. However, immigrants find themselves working for minimal pay as it happened in the past where slaves worked for lesser pay packages. In addition, housing conditions for many immigrants are demeaning as they cannot afford to house themselves decent housing because of their jobs (Reitz, Phan & Banerjee, 2009). In the past, slaves lived in poorly ventilated rooms as per the wishes of their masters. This aspect of inferiority has existed to date as Canadians do not opportunity to immigrants from other continents the opportunity to live in their expensive houses. Ironically, even for immigrants that have better income levels still find it hard to occupy houses in the up market as many Canadians are prejudicial to race and ethnicity (Anisef & Lanphier, 2003). This attribute creates an avenue for inequality as no one has more entitlement to living than immigrants residing in Canada. As per the view of many house owners in Canada, immigrants tend to have low education levels meaning that they may not be able to access quality work opportunities (Reitz, Phan & Banerjee, 2009). These landlords turn them away despite the availability of a vacant room in their premises as they view as unemployed and troublesome. In many instances, this may not be the actual case as these immigrants have made intense strides in ensuring that they acquire education that is the required quality. Therefore, immigrants may not necessarily suffer from unemployment but tend to work in deplorable work stations. Arguably, slavery seems to have set the standard to which immigrants could not surpass in terms of wages or salary levels. This means that no matter how hard immigrants in Toronto and Ontario try to access better housing conditions, their past will forever drag them in to misery (OHRC, 2007). On the contrary, visible discrimination against immigrants of minority descent is a contravention of the Human Rights Code existing in Ontario. Key considerations Over the years,

Cold War and Consumerists Mass Culture Essay Example | Topics and Well Written Essays - 2000 words

Cold War and Consumerists Mass Culture - Essay Example . The constraints resulting from World War Two and Great Depression led to a frustrated consumerism situation even more than the capitalist system rejection. The new consumerism had led most Americans and policy makers to believe that the under consumption situation in the country was the main cause of the slump. The government policy after the war had encouraged mass purchasing power instead of coming up with measures to equalize the wealth distribution. Consumer society had become a positive communism answer during the cold war. Despite the relations between freedom and consumption in these years, consumerism of the post war era was domesticated rather than hedonistic. It focused more on the nuclear family and suburban homes (Chafe 107). The period between 1960 and 1980 witnessed a number of challenges and changes making the consumer society stronger than ever. Among the challenges included the counterculture challenge on consumerism premises. The specter scarcity brought into question the cornucopia performance upon which the consumer society depended on. The consequent of this challenge was that consumption ended up being more ubiquitous. The socially and individualistic fragmenting consumerism existing today is believed to be rooted on the critique of consumerism that took place in 1960’s. The countercultural figures critiqued idealized and conformity indicates that most Americans preferred to achieve the authenticity through consumption (Breines and Breines 78). Consumerism began to modify its mass production practices in favor of segmented and flexible production in the demographically distinct markets. Consumerism has since then become adoptable to the hip and green. A good example of this is the energy situation crisis in 1970’s when politicians considered the shortage as being as a result of over production. This was rebuked as being naysayers. Consumerist trends toward fragmentation and individualistic consumptions have accelerated in the recent years leading to market triumphant. The resulting radical faith in the market virtues led to politicians to put moral gloss on the market culture unfettered growth in the 1980s. Consumerism also helped in the integration of the diversity of the inhabitants youth mass culture and cynical marketers through the equal division of multicultural segmented demographic units. This led to the shift from a spirited and integrative public popular culture to an increasingly solipsistic and privatized commercial culture in the early twentieth century (Bloom and Breines 142). Consumerist during this era adopted an ideological medal that adopted an unquestioning approach towards the production uses. This resulted to an increase in self-conscious ness in the manipulation

The Death Penalty for Drug Offences in Saudi Arabia A violation of Essay

The Death Penalty for Drug Offences in Saudi Arabia A violation of international human rights law - Essay Example Approximately two hundred years ago the history witnessed a war between the China and the United Kingdom on this issue. The drug barons in the different parts of the world caused higher number of casualties in the exchange of fire du between the drug dealers and the law enforcing agencies. To combat with this menace effectively, countries are focusing and funding on educating people, taking preventive measures and treatment program to save their future generation (Worldwide Drug Laws, 2012). It is a matter of fact that the United States of America today known as the largest illicit drug consumable country of the world. The American law enforcers, despite of their best efforts yet to see the desired results to weed out illicit drug consumption from its administrative jurisdiction and in the jurisdiction of other parts of the world. It is interesting to note that Americans while chasing the goose, sometimes even don’t mind to respect the boundaries and sovereignty of the indepen dent states. In this respect we may quote here the examples of Middle Eastern, South Asian and the African countries (Worldwide Drug Laws, 2012). In some parts of the world harmful drug control policies are strictly and rigidly enforced. Take the example of Malaysia and Thailand wherein the possessor of illegal drugs gets imprisonment of 15 to 20 years. Some countries are even more rigid in the drug policies they enforced. In Malaysia and Thailand possession of illicit drugs can result in 15 to 20 years in prison. In the mentioned countries, drug trafficking / distribution of illegal drugs amongst the users amounts to capital punishment in the shape of death sentence. The Indonesians are not far behind in awarding death sentence to drug traffickers irrespective of locals or foreigners. For the last seven years the Indonesian awarded ten Australians death penalty on the charge of drug smuggling into Indonesian territory (Worldwide Drug Laws, 2012). Death Penalty for Drug Offenders wo rldwide Hundreds of drug offenders met death penalty every year by rigidly enforced drug control laws. In this respect, we see two extreme scenarios i.e. increased executions and reduced moratorium. There are number of countries that have dropped death sentences whereas the other countries recommend death penalty to combat this menace effectively (IDPC, 2010). We have the best example in awarding death sentence to drug offenders are Malaysia and Singapore where many people in the yester years put to death on illicit drug related crimes. The exemplary punishment given to the law breakers helped above countries to reduce the number of crimes. Amongst 32 states, we have witnessed capital punishment on committing drug related crimes in Iran, Saudi Arabia, Singapore, Malaysia and China in the shape of death sentence. Although the majority of the European Scholars thought it to be the capital punishment for the drug offenders and a flagrant violation of international human rights law (IDP C, 2010). Due to best reasons known to the Chinese, China kept secret its statistics of death toll to the world. The exemplary punishment awarded to the drug offenders somehow proved instrumental in reducing the narcotics concerning crimes although much work to be done for its complete eradication (IDPC, 2010). Iran is no exception to it. In Iran such offences are unavoidable and attract

Sanctification Based on Calvins Theology Essay Example | Topics and Well Written Essays - 2500 words

Sanctification Based on Calvins Theology - Essay Example The first part will try to define morality while the succeeding section will tackle about the different meanings attributed to sanctification, giving emphasis on what is taught by Calvinism. In light of this, the issue that links sanctification with morality will be examined through a discussion on the definition of morality. This paper will conclude with its findings. In the strictest sense, morality refers to "which is innately regarded as right or wrong (Morality 2006)." There isn't a concise meaning associated with morality as it often refers to set of judgments and principles shared by individuals in within the same culture, religion, and philosophical concepts which separates and identifies actions which are right or wrong, acceptable and unacceptable. The concept of morality is often used by groups to regulate the functioning of their circle by setting a specific standard by which their members are subjected. In other words, the concept of morality serves as a regulating factor in maintaining the harmony in a group. We can see a problem of morality given this definition. We can see that morality varies from culture to culture, religion to religion, and sometimes even from individual to individual. Some actions are considered acceptable by a culture, while others see the same action as immoral. Examples of these are abortion, white lie, and euthanasia. Some groups and individuals consider these as permissible while others question the morality of such actions. Calvin's Theology John Calvin is one of the most famous theologian and ecclesiastical statesman. Through his revolutionary beliefs and teachings, he became the major French Protestant Reformer and was dubbed as the "most important figure in the second generation of the Protestant Reformation." His ideas of Christianity are found in his famous work Institutio Christianae Religionis (Institutes of the Christian Religion). John Calvin laid out the foundation of Calvinism which is one of the major factors that influenced the formation of the modern world (John Calvin 2002). One of the most important doctrines contained in Calvin's theology is the doctrine of original sin which is adopted from the Augustinian teachings. This doctrine supports the idea that the whole mankind has fallen before God when Adam and Eve fell prey to the temptation in the Garden of Eden. The sin committed by the first man is denoted as the original sin. At that point, sin entered the heart of men and everyone born on this earth has the original sin. Sin is what separates man from his creator. Therefore, the fall of man in the Garden of Eden makes man a slave of sin and every human being has an inclination to commit sin (The Teachings of John Calvin 2000). Institutes of the Christian Religion states that: When the will is enchained as the slave of sin, it cannot make a movement towards goodness, far less steadily pursue it. (2.3.5) Man alone has no power to save himself from sin. Even though his freewill was not removed from him, he cannot resist the urge to commit sin. However, God's great love and compassion for mankind made a remedy for this situation. Through the Son of God Jesus Christ, man was freed from the burden of sin. Calvin refers to this process as justification. Through this justification, man's original sin is forgiven. John Calvin also put forward that another

Research paper summary Carrying capacity Example | Topics and Well Written Essays - 500 words

Summary Carrying capacity - Research Paper Example The methodology employed is two pronged as mentioned. The laboratory study was first to be carried out. The study examined various components of the Maculinea arion like its feeding preferences, autumn food consumption and growth and the winter period weight loss. The sample size included a total of 69 caterpillars reared from the onset of their final instars in the late summer to the month of May. In addition, each caterpillar was kept in a seven cubic centimeter plastic box that was furnished with a small piece of moist sponge. During that period, fresh food was supplied to the specimens after every 2-3 days to ensure that there was a surplus in the food given to them. It is also important to note that caterpillars were categorized into different sets with each set provided with a different food type and composition to enable the accurate determination of the objectives of this study. Each caterpillar was also weighed weekly to and kept in a clean box with the resultant weight being recorded for each caterpillar. In addition to the variables obtained in the laboratory set up, published materials were also used for the purposes of the number and biomass of the immature stages of M. sabuleti that were available to final instar caterpillars of Maculinea orion. Finally, estimates were carried out from the mean body weight that was obtained 2 days before eclosion. The field study involved the examination of mortality rates of wild Maculinea arion adopted at different densities into Myrmica sabuleti nest. This was measured during a five-year period study on site X. The study involved the introduction of the caterpillars at different stages of the duration with excavations and counting being done. The obtained data was subsequently being recorded to monitor the changes and effects of the different seasons, eating habits and species behavior. As a combination of the two methods and integration

Modern Technology Has Brought the Resurgence of Identity Theft Essay Example for Free

Modern Technology Has Brought the Resurgence of Identity Theft Essay Identity theft is one crime that has spawned from technological advancements. Criminals have developed numerous strategies on how to steal confidential and personal information. Dealing with identity theft may be a challenge since law enforcement personnel may not be fully competent in handling the cases since they may lack the required skills to be able to deal with such a crime while private people and even businesses have lost much because of this type of crime. The number of cases of identity theft has been constantly on the rise; however, the prevalence of the crime may as well be blamed on modern technology itself. Modern technology has brought about many conveniences for ordinary people and even for identity thieves. From only less than 10,000 reported cases of identity theft in 1999, the figure steadily climbed reaching around 50,000 in 2003 and more than 80,000 in 2006 (Infocycle, 2007). In the United Kingdom, credit card fraud has also been consistently increasing. In 2007, over 7,000 credit cards and debit cards were either lost or stolen. CPP Card Protection has indicated a 77 percent increase in credit card fraud compared to the figure on 2006 (Experian QAS, 2008). According to a study by Gartner, identity theft claimed 15 million victims in 2006 alone. The US Justice Department has recorded 226 cases of identity theft in 2005 but in the first half of 2006 alone, there were already 432 cases. The FBI also indicated that it is working on 1,587 cases relating to identity theft (ITRC, 2007). Preventing identity theft may not be as easy as it seems. Joel Reidenberg and Lawrence Lessig said concentrating on the â€Å"architectures of control† to prevent identity theft is the way to go. Solove, on the other hand, indicates that â€Å"architectures of vulnerability† should also be considered in addition to â€Å"architectures of control†. According to Solove, shaping architectures should be the focal point in the protection of privacy and not on remedies and penalties. He noted that architectures often provide a vulnerable point that identity thieves take advantage of. It is this lack of security that identity thieves are able to use a person’s personal information. He suggests that a public identification system be created as a solution to the problem (Solove, 2003). It is exactly new technology that produces these architectures and they are greatly flawed since many people can still bypass its security functions evidenced by the prevalence of identity theft on the Internet. Identity theft has gained much notoriety in the advent of buying and selling on the Internet. However, identity thieves can still use the old methods for obtaining personal information. Common methods are stealing wallets or mails, looking through residential trashcans or business dumpsters, posing as someone legally permitted to access personal information such as credit reports, or bribing their way to get the information (Newman, et. al. 2005). A phishing scam is another method of getting personal information out of a person. The Anti-Phishing Workgroup indicated that there are only 4,564 phishing websites in July 2005 but the number increased to 23,670 as of July 2006. A study at the University of Indiana also indicated that 14 percent of phishing scams are successful which contradicts the Gartner report which indicates only a three percent success rate. The Gartner research also found out that financial losses from phishing scams were $137 million in 2004 rising to $2. 8 billion in 2006 (ITRC, 2007). The fight against identity theft may be considered rather ineffective since law enforcement personnel lack the necessary resources to combat such a crime which is computer-related. Britz indicates that this kind of crime requires law enforcers to have knowledge of computers and other digital stuff. It may be noted that many law enforcement agencies do not have well-trained personnel to handle such cases. These personnel may also be acting several capacities at a given time. Computer technology has increased at an exponential rate as did technology related crime and this would require that law enforcers be trained to effectively handle such crimes (Britz, 2004). As technology improves, security is being compromised and this can be proven by the increasing number of identity theft crimes. While it is true that online banking and other services on the Internet provide much convenience, it also provides lesser risks of capture for identity thieves. Law enforcers could do little do prevent identity theft or to investigate such since not all of them have the capacity to do so and identity thieves are improving their arsenal of identity stealing techniques. Technology might also be considered as the root of the prevalence of identity theft. Even as identity theft was not considered a crime before 1998, it has existed for a long time. Modern computing and telecommunications technology has once again popularized identity theft since identity thieves can better elude law enforcers compared to going to a bank and making a transaction using stolen information (Arnold, 2000). Legislation has always tried to address cyber crime, but it is challenging for lawmakers to keep up since technology quickly evolves and cyber crime evolves with it. A good approach would be improving security measures, educating users, adopting a vigilant approach in combating cyber crime and a police force that is well-equipped to handle such crimes (Alaganandam, et. al. , 2005). Identity theft and other cyber crimes are also classified as white-collar crimes, thus, offenders do not receive harsh penalties. They can even use the money plundered to pay for their defense and they serve at least only one year in prison (Arnold, 2000). Identity thieves must be dealt with harsher penalties since they operate on a much larger scale today and are even comparable to bank robbers only less inclined to being caught and given much less media attention. The number of cases of identity theft is increasing at an exponential rate but this could most likely be blamed on modern technology especially since the Internet has become commercialized. New technology comes with new opportunities for identity thieves to gain access to personal information and using it for personal gains. Legislation can address this problem but it would prove to be a challenge since identity thieves are finding new ways of how to steal personal information as technology develops. Legislation must also address this by rendering harsher penalties for cyber criminals as they operate just like ordinary criminals, the only difference is that they work discreetly and have not been given media attention. Also, the victims do not really know that they have been victimized until after some time the thieving takes places. References Alaganandam, H. , Mittal, P. , Singh, A. , Fleizach, C. , 6 December 2005. Cybercriminal Activity. Retrieved September 7, 2008, from sysnet. ucsd. edu/~cfleizac/WhiteTeam-CyberCrime. pdf Arnold, T. 2000 June. Internet Identity Theft: A Tragedy for Victims. Software and Information Industry Association. Retrieved September 7, 2008, from www. siia. net/software/pubs/iit-00. pdf Britz, M. (2004). Computer Forensics and Cyber Crime: An Introduction. Upper Saddle River, NJ: Pearson Prentice Hall. Experian QAS. 22 August 2008. Holiday Fraud Threat. Retrieved September 3, 2008, from http://www. qas. co. uk/company/data-quality-news/holiday_fraud_threat_2614. htm Identity Theft Resource Center. 30 April 2007. Facts and Statistics. Retrieved September 3, 2008, from http://www. idtheftcenter. org/artman2/publish/m_facts/Facts_and_Statistics. shtml Infocycle. (2007). Government Bodies Must Play Their Part in Securing Against Identity Theft. Retrieved September 3, 2008, from http://www. infocycle. co. uk/index. php? option=com_contenttask=viewid=43Itemid=43 Newman, G. McNally, M. 2005 July. Identity Theft Literature Review. Retrieved September 3, 2008, from http://www. ncjrs. gov/pdffiles1/nij/grants/210459. pdf. Solove, D. (2003). Privacy, and the Architecture of Vulnerability. Hastings Law Journal, 54. p. 1227. Retrieved September 3, 2008, from http://ssrn. com/abstract=416740

Literature Review On Mobile Apps Information Technology Essay

Literature Review On Mobile Apps Information Technology Essay In order to achieve a competitive edge over competitors by investing into emerging ICTs and growing their international market, Mobile Construction Ltd is considering innovative ways of providing their service to global customers. As the Global Reach Manager, the CEO asked to explore the potential of delivery and retrieval service for enterprise-wide, on-demand mobile Apps. Also, the Global Reach manager needs to identify benefits and barriers of using mobile Apps, as well as strategy for effective use of existing Apps and development of new Apps. 2 Literature review on mobile Apps 2.1 Mobile Application Market Early mobile application solutions required enterprises to choose between cradle-based synchronization through a wire line network or a pure online wireless solution (PENTA group, 2010). However, Mobile applications are a rapidly rising segments of the international mobile market, which consist the software runs on a mobile device and performs certain tasks for the clients. Because of the various functions including user interface for basic telephone and messaging service as well as advanced services, mobile Apps are widely used by customs. Also, mobile Apps are a large and continuously growing market and served by an increasing number of mobile App developers, publishers and providers (the Mobile Marketing Association group, 2008). New research suggests that the global market for mobile applications will explode over next two years. Research has been done for Getjar, the worlds second biggest Apps store, said that the market will grow to $17.5bn (Â £12bn) in the next two years and downloads would rise from 7bn last year to 50bn by 2012 a 92% increase (BBC News, 2010). 2.2 Existing Mobile Applications For a technical aspect, mobile Apps can be divided by the runtime environment they are executed: Native platforms and operating systems, such as Symbian, Windows Mobile and Linux. Mobile Web/browser runtimes, such as Webkit, Mozilla/Firefox, Opera Mini and RIM. Other managed platforms and virtual machines, such as Java/J2ME, BREW, FlashLite and Silverlight. (Mobile Marketing Association group, 2008) IPhone has acted as a revolution of global mobile phones. It has set a platform to develop all sorts of mobile Apps helping paint a better picture in mobile computing. The advantages of iPhone is that it is numerous with multi-touch interface, accelerometer, GPS, proximity sensor, dialer, sqlite3 database, OpenGL ES, Quartz, Encryption, Audio ,Game and Animation , Address book and Calendar including latest features of iPhone Gaming . Windows mobile application is the latest technology every mobile technique should process. This technology allows the user to browse the internet, send receive mails, check with schedules contacts, and prepare presentations, in short manage your whole business with the usage of your mobile. Android has been creating waves in the coming times with high technical interface in the mobile world. This latest innovation helps the publishers to deliver applications directly to the end user and easy downloads of applications can be achieved. The term BlackBerry has become the synonyms of the word Smart and Trendy. BlackBerry Smartphone are the worlds most desired integrated communication device. This brilliant application not only meets a single need of one person but the usage can extend to an entire enterprise be it a small scale or a huge industry. (Maadesigns.co.uk, 2010) 2.3 Infrastructure Cellular technology have largely expanded the frequency use of mobile phones, the first generation cellular mobile telephones developed by using incompatible analogue technologies while the second generation cellular mobile telephone and GMS was developed by using digital technology in 1980 (Gans G.S. et al, 2003). Over thirty years of mobile cellular networks advancements, data transmission over cellular systems has been major breakthrough in recent years. Third generation systems (3G) have been developed as new mobile cellular networks, which is known as IMT-2000 (International Mobile Telephony-2000) by ITU(Wiley J. Sons, 2005). 3G have met the single-user data rates requirement of the IMT-2000 on a technical level. However, it is limited 3G services in some areas such as video telephony (Agilent Technologies, 2008). ITU has received six candidate technology submissions for the global 4G mobile wireless broadband technology known as IMT-Advanced. And it is expected in October 2010 , the selected technologies to be accorded the official designation of IMT-Advanced to qualify as true 4G technologies (ITU, 2009). The south Korean government is already developing 5G access which may be ready soon after 4G service put into market, although 4G cellular wireless still waiting (MNM Media, 2009). Cloud computing is described as both a platform and type of application. As a platform, cloud computing can be physical machines or virtual machines dynamically servers as needed. Advanced cloud computing include other computing resources such as storage area networks (SANs), network equipment, firewall and other security devices. As a type of applications, cloud computing use large data centres and powerful servers host Web application and Web services since it can be extended accessible through the internet. It is said that anyone can access a cloud application with a suitable internet connection and a standard browser (IBM, 2007). Typically, it can divid cloud computing into three levels of service, which support virtualization and management of differing levels of the solution stack, offerings: Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a service (IaaS) (Oracle Corporation, 2009). 3 Opportunities for mobile Apps in construction The PENTA team (2010) insists that the construction industry is a mobile workforce, which comprised of a range of companies with self-performing Electrical and Mechanical contractors to Engineering and Construction firms to specialty concrete and plumbing. Mobile phone is the most convenient device to deliver mobile Apps, particularly for emerging because of it is a daily used device. The most use mobile Apps in construction industry are calculation, drawing, management, measurement and video records which are based on variety of software. 3.1Calculation It is quite normal for using smart phones as calculators in different areas. In construction industry, calculations can be used anywhere, such as, material supply, finance calculation, dynamic calculation, structure calculation and calculation in measurement and design. Generally speaking, the calculation in construction industry is not too complicate, therefore it is convenient to install calculation software for smart phones in order to get emergency result and check and calculate. Currently, there are several kinds of mobile apps such as Construction advantage calculator 2.0, AFHTech RC Columns and Beams 1.0.0 and PocketStatics 2.01. 3.2 Drawing Nowadays the architecture drawing is mainly based on computers, by using powerful design software architects can get the most accurate and clear drawings. Smart phone can also works as minicomputer for architecture drawing by using related software to check the original drawing and do some changes. Also, the architects can create the sketch work and get design ideas in record time without leaving the clients. Furthermore, they can use massage function of smart phones to send their works or ideas to the company. Power CAD Site Master CE 1 has been welcomed by construction workers for years. 3.3 Management Computer is used by construction manager and builder to get technological solutions of scheduling and delivery the construction process efficiently. Also, site managers and builders use computer to manage contracts, manage delivery, record construction process and manage and record risk happened in construction process. Since, site manager and builders cannot get computers anywhere, it is quite convenient for them to use smart phones with mobile Apps to check and complete their works, particularly in emergency situation. The popular Apps for construction management are Construction Manager 2.5 and Penta Mobile Field Reporting. 3.4 Measurement Instead of big and heavy measurement equipment for construction measurement work, smart phone with mobile Apps can work well for the measurement task. By using GPS function of smart phones, you will not lose or cannot find the construction site. Also, mobile Apps can make smart phones work as plumb, to get horizontal, vertical and spirit level measuring. Most popular Apps are Kais Bubble Level.Net 2.2 and Plumb-bob. 3.5 Camera record Camera record is a powerful App for smart phones using in construction area. It can take pictures and videos for the visible construction information such as gather site information, get risk information, record construction process, store property information and so on. The Apps can get literature record works together with camera can make the construction information more clear and visible. Also, it will make video conference on mobile phone become more and more popular. 4 Infrastructure/system requirements As mobile phone needs the infrastructures to support it works, the quality of infrastructure/system requirements is deeply related to the quality of mobile Apps service. The infrastructure/system requirements is summarized as: good network to support data requirement, developed device to support the Apps works, high speed operation platform to support the Apps work well. 4.1 Network Signal quality is almost the most important factor which effects the mobile communication and mobile Apps works. Since 3G network is the most popular wireless network for Mobile Apps, the majority of developed countries have been developed the communication technologies. Current mobile Apps are mainly produced based on 3G network system, and there are lots of limitation and restrict on improvement of Mobile Apps because of the limitation of data transmission. Therefore, it seems that it is impossible to widely develop the video transmission Apps at this moment. 4G system may make it possible for widely developed the Apps in construction areas when it become commercial used. 4.2 Device The mobile phone device is known as the hardware to apply Mobile Apps. The processor is the heart of Mobile device which must quick enough to support the calculation speed. As well, the battery is required powerful enough to support the mobile phone works long time. The screen and keyboard need to convenient for the use of Mobile Apps in construction area. The hard drive or storage space need to enlarge for video or files to store and the run of systems and mobile Apps. The newest Apple iPhone 3GS with 32 G storage space which can record clear video about one day on theory, however, the battery can just support the video process less than 3 hours. 4.3 Operation system Operation system is the platform of mobile Apps software and many mobile Apps software are produced based on the operation systems. For example, the operation system requirement of calculation Apps such as Construction advantage calculator 2.0, AFHTech RC Columns and Beams 1.0.0 and PocketStatics 2.01 is Windows Mobile 2003. Currently, the most popular smart phone operation systems are Apple OS, RIM Black Berry OS, Symbian OS, Android OS and Microsoft Mobile OS. The diversity of operation systems creates trouble for mobile Apps work well under different operation systems. The adaptability of mobile Apps and operation system should be improved because of the difference of the operation systems. 5 Implementation Strategy Since 4G system will make mobile Apps more powerful and more convenient, smart phones will play more and more important roles in construction industry. The implementation strategy on mobile Apps which used in construction will be created based on 4G system. Because of the 4G system can enhance peak data rates to support advanced services and applications and the targets of 4G system are established as 100 Mbps for high and 1 Gbps for low mobility (Agilent Technologies, 2008). Thus, by developing the existing mobile Apps in construction areas, it can create the implementation strategy based on 4G system can focus on e-business, video conference and GPS measurement. 5.1 E- business With the high speed data transfer speed, the mobile Apps for E-business can be developed. The construction companies can receive and send out their contracts immediately after the decision making. Also, the companies can negotiate the contracts price and amend their contracts without delay by mobile Apps. The construction managers can manage the contract by mobile Apps easily, by the wireless with their company computers. Furthermore, the implemented E-business Apps allow construction managers to get the detail information of their clients, material suppliers and their employees. Thus, it is quite necessary to implement E-business in construction organizations. 5.2 Video transmission 4G system can offer high data delivery speed which allows video conference and video transmission as mobile Apps more frequent and more effective. During the 3G period, it can also using video transmission though smart phones, however, the video transfer speed and quality is so poor that it cannot for widely use in construction area. This situation will be totally changed during 4G period when high speed data transfer can enable video conference and video record transmission during different stakeholders in construction organization. Also, video transmission can be developed as distance guidance programme, when the risk happens the recorded video can be transferred to the professional group who communication by video conference with smart phones, also they can guide the construction workers to solved the problems by video conference. Therefore, video transmission will share a large market of mobile Apps in construction area. 5.3 GPS measurement GPS measurement is frequently used in construction area, particularly in highway construction and energy supply line construction. The original GPS equipments is big and heavy to carry, it mean the mobility of GPS equipments are poor. It can implement the mobile phone to replace the GPS equipments as measurement tools through the mobile Apps. Currently it can use GPS Apps in smart phone for location guides. Since the smart phone is quite convenient to carry and it can work as plump equipment with mobile Apps, it is essential to implement the Apps work together with GPS Apps and developed new GPS measurement Apps. Also, Infrared measurements can be used as measurement apps in mobile phone. 6 Benefits and Barriers The benefits and barriers of the mobile Apps in construction areas are difficult indentified sometimes. However, it can general get the benefits and barriers factors for using mobile Apps in construction areas. 6.1 Benefits The benefits of using mobile Apps in construction areas cannot calculation by how many pounds or dollars, since you cannot evaluate the apps used during emergency. Generally, the benefits of using mobile Apps can be defined as saving transport fees and dealing with emergency. 6.1.1 Saving transport fees Mobile Apps are used for connecting with the construction company groups in different areas. Transport fees are saved since mobile Apps can take the roles of many function tools such as camera, pump and professional calculator and so on. As well, the mobile can used as camera, many managers are not necessary to get site visit in order to acquaint the construction site. 6.1.2 Dealing with emergency Many emergencies happened in construction area need professional tool to deal with; however, mobile phone with the Apps in construction area can act as the professional tools sometimes. There are huge benefits of mobile phone Apps used for emergency, which cannot measured by money. 6.2 Barriers Since it needs to develop mobile Apps for enterprise-wide and on-demand mobile service delivery, the network coverage level in different countries has great gap and the internet security problems cannot solved will be the main barriers. 6.2.1 Unbalanced Network coverage Because the unbalanced economic and technology development of the world, the developed countries such as the UK, the US and the EU countries have already complete their 3G network coverage a decades before, however, the developing countries such as China has just begin the coverage project of 3G network. The developed countries plan to develop 4G network coverage since 2012, but for the developing countries may be need another decade. 6.2.2 Security problems Using wireless connection in transferring information from construction site to the main office and having that information stored in mobile memory, the security is a big issue which is concerned by many construction organizations. The stolen of mobile device, the leak of commercial secret and the attack by hacker, all these problems will cased the lost of company benefits. Thus, it is quite essential to solve the security problems in mobile Apps. 7 New Apps Development The aim of the development this new Apps is offering the full service delivery for construction companies globally. The idea of the new App based on 4G system and cloud computing used in construction area, thus the name of the new App is cloud computing construction programme. 7.1 Cloud computing construction programme (CCCP) Cloud computing construction programme (CCCP) is an idea of new mobile Apps in construction area. The programme will developed based on 4G system, which requires high data transfer speed. The functions of the new App will contain commercial management, GPS measurement, video record and transmission, architecture drawing and risk management. Considering the compatibility of different functions Apps work in one programme, it is planned to divide the programme into small function programmes. The structure of the programme is showed as figure 7.1. C:Documents and SettingsxuweiweiDesktop11.jpg Figure 7.1 Cloud computing construction programme structure 7.2 Cloud Computing Since the CCCP is a big programme for smart phone device and operation system, it is considering the new App will use cloud computing to share the capitation and run speed by the Internet. Because of the App can share the Internet as part of processor, the hardware requirements of smart phones to run the new App will be greatly reduced. Also, by using advanced cloud computing to support the new App, it can share other computing resources and data centres and powerful servers host Web. Although this App is support by cloud computing, cloud computing is totally separate from the operational system of the mobile device. In this programme cloud computing is used both as Apps and platform. Conclusion The use of mobile Apps in construction organizations has great benefits and advantages. Also, there are many barriers for develop mobile Apps for enterprise-wide, on-demand mobile service delivery and retrieval. However, the barriers of mobile Apps in construction area will be less and less because of the development of mobile network coverage and mobile phone device development.

The Electromagnetic Waves And Spectrum

The Electromagnetic Waves And Spectrum The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The electromagnetic spectrum of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object. The electromagnetic spectrum is a continuum of all electromagnetic waves arranged according to frequency and wavelength. The electromagnetic spectrum extends from low frequencies used for modern radio to gamma radiation at the short-wavelength end, covering wavelengths from thousands of kilometres down to a fraction of the size of an atom. The long wavelength limit is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length, although in principle the spectrum is infinite and continuous. The sun, earth, and other bodies radiate electromagnetic energy of varying wavelengths. Electromagnetic energy passes through space at the speed of light in the form of sinusoidal waves. The wavelength is the distance from wave crest to wave crest (see figure below). Light is a particular type of electromagnetic radiation that can be seen and sensed by the human eye, but this energy exists at a wide range of wavelengths. The micron is the basic unit for measuring the wavelength of electromagnetic waves. The spectrum of waves is divided into sections based on wavelength. The shortest waves are gamma rays, which have wavelengths of 10e-6 microns or less. The longest waves are radio waves, which have wavelengths of many kilometres. The range of visible consists of the narrow portion of the spectrum, from 0.4 microns (blue) to 0.7 microns (red). RANGE OF THE SPECTRUM EM waves are typically described by any of the following three physical properties: the frequency f, wavelength ÃŽÂ », or photon energy E. Frequencies range from 2.4ÃÆ'-1023 Hz (1 GeV gamma rays) down to the local plasma frequency of the ionized interstellar medium (~1kHz). Wavelength is inversely proportional to the wave frequency, so gamma rays have very short wavelengths that are fractions of the size of atoms, whereas wavelengths can be as long as the universe. Photon energy is directly proportional to the wave frequency, so gamma rays have the highest energy (around a billion electron volts) and radio waves have very low energy (around femto electron volts). These relations are illustrated by the following equations: Where: c = 299,792,458 m/s is the speed of light in vacuum and h = 6.62606896(33) ÃÆ'-10à ¢Ã‹â€ Ã¢â‚¬â„¢34 J s = 4.13566733(10) ÃÆ'-10à ¢Ã‹â€ Ã¢â‚¬â„¢15 eV s is Plancks constant. Whenever electromagnetic waves exist in a medium with matter, their wavelength is decreased. Wavelengths of electromagnetic radiation, no matter what medium they are travelling through, are usually quoted in terms of the vacuum wavelength, although this is not always explicitly stated. Generally, EM radiation is classified by wavelength into radio wave, microwave, infrared, the visible region we perceive as light, ultraviolet, X-rays and gamma rays. The behaviour of EM radiation depends on its wavelength. When EM radiation interacts with single atoms and molecules, its behaviour also depends on the amount of energy per quantum (photon) it carries. Spectroscopy can detect a much wider region of the EM spectrum than the visible range of 400 nm to 700 nm. A common laboratory spectroscope can detect wavelengths from 2 nm to 2500 nm. Detailed information about the physical properties of objects, gases, or even stars can be obtained from this type of device. Spectroscopes are widely used in astrophysics. For example, many hydrogen atoms emit a radio wave photon which has a wavelength of 21.12 cm. Also, frequencies of 30 Hz and below can be produced by and are important in the study of certain stellar nebulae and frequencies as high as 2.9ÃÆ'-1027 Hz have been detected from astrophysical sources. - The Spectrum of Electromagnetic Waves While the classification scheme is generally accurate, in reality there is often some overlap between neighbouring types of electromagnetic energy. For example, SLF radio waves at 60 Hz may be received and studied by astronomers, or may be ducted along wires as electric power, although the latter is, strictly speaking, not electromagnetic radiation at all (see near and far field) The distinction between X and gamma rays is based on sources: gamma rays are the photons generated from nuclear decay or other nuclear and sub nuclear/particle process, whereas X-rays are generated by electronic transitions involving highly energetic inner atomic electrons. Generally, nuclear transitions are much more energetic than electronic transitions, so usually, gamma-rays are more energetic than X-rays, but exceptions exist. By analogy to electronic transitions, muonic atom transitions are also said to produce X-rays, even though their energy may exceed 6 mega electron volts (0.96 pJ), whereas there a re many (77 known to be less than 10 keV (1.6 fJ)) low-energy nuclear transitions (e.g. the 7.6 eV (1.22 aJ) nuclear transition of thorium-229), and despite being one million-fold less energetic than some muonic X-rays, the emitted photons are still called gamma rays due to their nuclear origin. Also, the region of the spectrum of the particular electromagnetic radiation is reference-frame dependent (on account of the Doppler shift for light) so EM radiation which one observer would say is in one region of the spectrum could appear to an observer moving at a substantial fraction of the speed of light with respect to the first to be in another part of the spectrum. For example, consider the cosmic microwave background. It was produced, when matter and radiation decoupled, by the de-excitation of hydrogen atoms to the ground state. These photons were from Lyman series transitions, putting them in the ultraviolet (UV) part of the electromagnetic spectrum. Now this radiation has undergone enough cosmological red shift to put it into the microwave region of the spectrum for observers moving slowly (compared to the speed of light) with respect to the cosmos. However, for particles moving near the speed of light, this radiation will be blue-shifted in their rest frame. The highest energy cosmic ray protons are moving such that, in their rest frame, this radiation is blueshifted to high energy gamma rays which interact with the proton to produce bound quark-antiquark pairs (pions). This is the source of the GZK limit Radio Waves: whose wavelength range from more than 104 m to about 0.1m, are the results of charges accelerating through conducting wires. They are generated by such electronic devices as LC oscillators and are used in radio and television communication systems. Radio waves generally are utilized by antennas of appropriate size (according to the principle of resonance), with wavelengths ranging from hundreds of meters to about one millimetre. They are used for transmission of data, via modulation. Television, mobile phones, wireless networking and amateur radio all use radio waves. The use of the radio spectrum is regulated by many governments through frequency allocation. Radio waves can be made to carry information by varying a combination of the amplitude, frequency and phase of the wave within a frequency band. When EM radiation impinges upon a conductor, it couples to the conductor, travels along it, and induces an electric current on the surface of that conductor by exciting the electrons of the conducting material. This effect (the skin effect) is used in antennas. EM radiation may also cause certain molecules to absorb energy and thus to heat up, causing thermal effects and sometimes burns. This is exploited in microwave ovens. Microwaves: The super high frequency (SHF) and extremely high frequency (EHF) of microwaves come next up the frequency scale. Microwaves are waves which are typically short enough to employ tubular metal waveguides of reasonable diameter. They have wavelengths ranging from approximately 0.3m to 10-4 m and are also generated by electronic devices. Because of their short wave lengths, they are well suited for radar system and for studying atomic and molecular properties of matter. Microwave ovens are an interesting domestic application of these waves. It has been suggested that the solar energy could be harnessed by beaming microwaves to the earth from a solar collector in space. Microwave energy is produced with klystron and magnetron tubes, and with solid state diodes such as Gunn and IMPATT devices. Microwaves are absorbed by molecules that have a dipole moment in liquids. In a microwave oven, this effect is used to heat food. Low-intensity microwave radiation is used in Wi-Fi, although this is at intensity levels unable to cause thermal heating. Volumetric heating, as used by microwaves, transfer energy through the material electromagnetically, not as a thermal heat flux. The benefit of this is a more uniform heating and reduced heating time; microwaves can heat material in less than 1% of the time of conventional heating methods. When active, the average microwave oven is powerful enough to cause interference at close range with poorly shielded electromagnetic fields such as those found in mobile medical devices and cheap consumer electronics. Infrared Waves: have wavelengths ranging from approximately 10-3m to the longest wavelength of visible light, 710-7m. These waves, produced by molecules and room temperature objects, are readily absorbed by most materials. The infrared energy absorbed by a substance appears as internal energy because the energy agitates objects atoms, increasing their vibrational or translational motion, which results in a temperature increase. Infrared radiation has practical and scientific applications in many areas, including physical therapy, IR photography and vibrational spectroscopy. The infrared part of the electromagnetic spectrum covers the range from roughly 300 GHz (1 mm) to 400 THz (750 nm). It can be divided into three parts: Far-infrared, from 300 GHz (1 mm) to 30 THz (10 ÃŽÂ ¼m). The lower part of this range may also be called microwaves. This radiation is typically absorbed by so-called rotational modes in gas-phase molecules, by molecular motions in liquids, and by phonons in solids. The water in the Earths atmosphere absorbs so strongly in this range that it renders the atmosphere effectively opaque. However, there are certain wavelength ranges (windows) within the opaque range which allow partial transmission, and can be used for astronomy. The wavelength range from approximately 200 ÃŽÂ ¼m up to a few mm is often referred to as sub-millimetre in astronomy, reserving far infrared for wavelengths below 200 ÃŽÂ ¼m. Mid-infrared, from 30 to 120 THz (10 to 2.5 ÃŽÂ ¼m). Hot objects (black-body radiators) can radiate strongly in this range. It is absorbed by molecular vibrations, where the different atoms in a molecule vibrate around their equilibrium positions. This range is sometimes called the fingerprint region since the mid-infrared absorption spectrum of a compound is very specific for that compound. Near-infrared, from 120 to 400 THz (2,500 to 750 nm). Physical processes that are relevant for this range are similar to those for visible light. Visible light: It is the most familiar form of electromagnetic spectrum the human eye can detect. Light is produced by the rearrangement of electrons in atoms and molecules. The various wavelengths of visible light, which correspond to different colours, range from red (ÃŽÂ »=710-7) to violet (ÃŽÂ »=410-7). The sensitivity of the human eye is a function of wavelength, being a maximum of 5.510-7m. This is the range in which the sun and stars similar to it emit most of their radiation. It is probably not a coincidence that the human eye is sensitive to the wavelengths that the sun emits most strongly. Visible light (and near-infrared light) is typically absorbed and emitted by electrons in molecules and atoms that move from one energy level to another. The light we see with our eyes is really a very small portion of the electromagnetic spectrum. A rainbow shows the optical (visible) part of the electromagnetic spectrum; infrared (if you could see it) would be located just beyond the red side of the rainbow with ultraviolet appearing just beyond the violet end. Electromagnetic radiation with a wavelength between 380 nm and 760 nm (790-400 terahertz) is detected by the human eye and perceived as visible light. Other wavelengths, especially near infrared (longer than 760 nm) and ultraviolet (shorter than 380 nm) are also sometimes referred to as light, especially when the visibility to humans is not relevant. If radiation having a frequency in the visible region of the EM spectrum reflects off an object, say, a bowl of fruit, and then strikes our eyes, this results in our visual perception of the scene. Our brains visual system processes the multitude of reflected frequencies into different shades and hues, and through this not-entirely-understood psychophysical phenomenon, most people perceive a bowl of fruit. At most wavelengths, however, the information carried by electromagnetic radiation is not directly detected by human senses. Natural sources produce EM radiation across the spectrum, and our technology can also manipulate a broad range of wavelengths. Optical fiber transmits light which, although not suitable for direct viewing, can carry data that can be translated into sound or an image. The coding used in such data is similar to that used with radio waves. Ultraviolet light: These cover wavelengths ranging from approximately 410-7 to 610-10m. The sun is an important source of ultraviolet (UV) light, which is the main cause of sun burn. Sunscreen lotions are transparent to visible light but absorb most of the ultraviolet light. The higher a sunscreens solar protection factor, or SPF, the greater the percentage of UV light absorbed. Ultraviolet rays have also been implicated in the formation of cataracts, a clouding of lens inside the eye. Most of the UV light from the sun is absorbed by ozone (O3) molecules in the earths upper atmosphere, in a layer called the stratosphere. This ozone shield converts lethal high energy UV energy into IR radiation, which in turn warms the stratosphere. Next in frequency comes ultraviolet (UV). This is radiation whose wavelength is shorter than the violet end of the visible spectrum, and longer than that of an X-ray. Being very energetic, UV can break chemical bonds, making molecules unusually reactive or ionizing them (see photoelectric effect), in general changing their mutual behaviour. Sunburn, for example, is caused by the disruptive effects of UV radiation on skin cells, which is the main cause of skin cancer, if the radiation irreparably damages the complex DNA molecules in the cells (UV radiation is a proven mutagen). The Sun emits a large amount of UV radiation, which could quickly turn Earth into a barren desert. However, most of it is absorbed by the atmospheres ozone layer before reaching the surface. X-rays: They have wavelengths in the range from approximately 10-8m to 10-12m. The most common source of x-rays is the stopping of high-energy electrons upon bombarding a metal target. X-rays are used as a diagnostic tool in medicine (a process known as radiography) and as a treatment for certain forms of cancer as well as for high-energy physics and astronomy.. Because x-rays can damage or destroy living tissues and organisms, care must be taken to avoid unnecessary exposure or over exposure. X-rays are also used in the study of crystal structure because x-ray wavelengths are comparable to the atomic separation distances in solids (about 0.1nm). Hard X-rays have shorter wavelengths than soft X-rays., Neutron stars and accretion disks around black holes emit X-rays, which enable us to study them. X-rays are given off by stars and are strongly emitted by some types of nebulae. Gamma rays: After hard X-rays comes gamma rays, which were discovered by Paul Villard in 1900, these are the most energetic photons, having no defined lower limit to their wavelength. They are electromagnetic waves emitted by radioactive nuclei (such as 60Co and 137Cs) and during certain nuclear reactions. High-energy gamma rays are a component of cosmic rays that enter the earths atmosphere from space. They have wavelength ranging from approximately 10-10m to less than 10-14m. Gamma rays are highly penetrating and produce serious damage when absorbed by living tissues. Consequently those working near such dangerous radiation must be protected with heavily absorbing material such as thick layers of lead. They are useful to astronomers in the study of high energy objects or regions, and find a use with physicists thanks to their penetrative ability and their production from radioisotopes. Gamma rays are also used for the irradiation of food and seed for sterilization, and in medicine they are used in radiation cancer therapy and some kinds of diagnostic imaging such as PET scans. The wavelength of gamma rays can be measured with high accuracy by means of Compton scattering. Note: There are no precisely defined boundaries between the bands of the electromagnetic spectrum. Radiations of some types have a mixture of the properties of those in two regions of the spectrum. For example, red light resembles infrared radiation in that it can resonate some chemical bonds. Application Areas of Electromagnetic Waves Electromagnetic Waves in the modern world have led to evolvement of many advanced communication systems some of them are radio, television, radars, etc. We would now focus on how these electromagnetic waves which carry energy and momentum are used in various applications round the globe. TELEMETRY Telemetry is the process of making measurements from a remote location and transmitting those measurements to receiving equipment. The earliest telemetry systems, developed in the United States during the 1880s, monitored the distribution and use of electricity in a given region, and relayed this information back to power companies using telephone lines. By the end of World War I, electric companies used the power lines themselves as information relays, and though such electrical telemetry systems remain in use in some sectors, most modern telemetry systems apply radio signals. An example of a modern telemetry application is the use of an input device called a transducer to measure information concerning an astronauts vital signs (heartbeat, blood pressure, body temperature, and so on) during a manned space flight. The transducer takes this information and converts it into an electrical impulse, which is then beamed to the space monitoring station on Earth. Because this signal carries information, it must be modulated, but there is little danger of interference with broadcast transmissions on Earth. Typically, signals from spacecraft are sent in a range above 10 10 Hz, far above the frequencies of most microwave transmissions for commercial purposes. RADAR Radio waves can be used to send communication signals, or even to cook food; they can also be used to find and measure things. One of the most obvious applications in this regard is radar, an acronym for RAdio Detection And Ranging. Radio makes it possible for pilots to see through clouds, rain, fog, and all manner of natural phenomena-not least of which is darkness. It can also identify objects, both natural and manmade, thus enabling a peacetime pilot to avoid hitting another craft or the side of a mountain. On the other hand, radar may help a pilot in wartime to detect the presence of an enemy. Nor is radar used only in the skies, or for military purposes, such as guiding missiles: on the ground, it is used to detect the speeds of objects such as automobiles on an interstate highway, as well as to track storms. In the simplest model of radar operation, the unit sends out microwaves toward the target, and the waves bounce back off the target to the unit. Though the speed of light is reduced somewhat, due to the fact that waves are travelling through air rather than through a vacuum, it is, nonetheless, possible to account for this difference. Hence, the distance to the target can be calculated using the simple formula d = vt, where d is distance, v is velocity, and t is time. Typically, a radar system includes the following: a frequency generator and a unit for controlling the timing of signals; a transmitter and, as with broadcast radio, a modulator; a duplexer, which switches back and forth between transmission and reception mode; an antenna; a receiver, which detects and amplifies the signals bounced back to the antenna; signal and data processing units; and data display units. In a monostatic unit-one in which the transmitter and receiver are in the same location-the unit has to be continually switched between sending and receiving modes. Clearly, a bistatic unit-one in which the transmitter and receiver antennas are at different locations-is generally preferable; but on an airplane, for instance, there is no choice but to use a monostatic unit. In order to determine the range to a target-whether that target be a mountain, an enemy aircraft, or a storm-the target itself must first be detected. This can be challenging, because only a small portion of the transmitted pulse comes back to the receiving antenna. At the same time, the antenna receives reflections from a number of other objects, and it can be difficult to determine which signal comes from the target. For an aircraft in a wartime situation, these problems are compounded by the use of enemy countermeasures such as radar jamming. Still another difficulty facing a military flyer is the fact that the use of radar itself-that is the transmission of microwaves-makes the aircraft detectable to opposing forces. MICROWAVE OVENS The same microwaves that transmit FM and television signals-to name only the most obviously applications of microwave for communication-can also be harnessed to cook food. The microwave oven, introduced commercially in 1955, was an outgrowth of military technology developed a decade before. During World War II, the Raytheon Manufacturing Company had experimented with a magnetron, a device for generating extremely short-wavelength radio signals as a means of improving the efficiency of military radar. While working with a magnetron, a technician named Percy Spencer was surprised to discover that a candy bar in his pocket had melted, even though he had not felt any heat. This led him to considering the possibilities of applying the magnetron to peacetime uses, and a decade later, Raytheons radar range hit the market. Those early microwave ovens had none of varied power settings to which modern users of the microwave-found today in two-thirds of all American homes-are accustomed. In the first microwaves, the only settings were on and off, because there were only two possible adjustments: either the magnetron would produce, or not produce, microwaves. Today, it is possible to use a microwave for almost anything that involves the heating of food that contains water-from defrosting a steak to popping popcorn. As noted much earlier, in the general discussion of electromagnetic radiation, there are three basic types of heat transfer: conduction, convection, and radiation. Without going into too much detail here, conduction generally involves heat transfer between molecules in a solid; convection takes place in a fluid (a gas such as air or a liquid such as water); and radiation, of course, requires no medium. A conventional oven cooks through convection, though conduction also carries heat from the outer layers of a solid (for example, a turkey) to the interior. A microwave, on the other hand, uses radiation to heat the outer layers of the food; then conduction, as with a conventional oven, does the rest. The difference is that the microwave heats only the food-or, more specifically, the water, which then transfers heat throughout the item being heated-and not the dish or plate. Thus, many materials, as long as they do not contain water, can be placed in a microwave oven without being melted or burned. Metal, though it contains no water, is unsafe because the microwaves bounce off the metal surfaces, creating a microwave buildup that can produce sparks and damage the oven. In a microwave oven, microwaves emitted by a small antenna are directed into the cooking compartment, and as they enter, they pass a set of turning metal fan blades. This is the stirrer, which disperses the microwaves uniformly over the surface of the food to be heated. As a microwave strikes a water molecule, resonance causes the molecule to align with the direction of the wave. An oscillating magnetron causes the microwaves to oscillate as well, and this, in turn, compels the water molecules to do the same. Thus, the water molecules are shifting in position several million times a second, and this vibration generates energy that heats the water. RADIO COMMUNICATION Among the most familiar parts of the electromagnetic spectrum, in modern life at least, is radio. In most schematic representations of the spectrum, radio waves are shown either at the left end or the bottom, as an indication of the fact that these are the electromagnetic waves with the lowest frequencies, the longest wavelengths, and the smallest levels of photon energy. Included in this broad sub-spectrum, with frequencies up to about 10 7 Hertz are long-wave radio, short-wave radio, and microwaves. The areas of communication affected are many: broadcast radio, television, mobile phones, radar-and even highly specific forms of technology such as baby monitors. Though the work of Maxwell and Hertz was foundational to the harnessing of radio waves for human use, the practical use of radio had its beginnings with Marconi. During the 1890s, he made the first radio transmissions, and, by the end of the century, he had succeeded in transmitting telegraph messages across the Atlantic Ocean-a feat which earned him the Nobel Prize for physics in 1909. Marconis spark transmitters could send only coded messages, and due to the broad, long-wave length signals used, only a few stations could broadcast at the same time. The development of the electron tube in the early years of the twentieth century, however, made it possible to transmit narrower signals on stable frequencies. This, in turn, enabled the development of technology for sending speech and music over the airwaves. THE DEVELOPMENT OF AM AND FM. A radio signal is simply a carrier: the process of adding information-that is, complex sounds such as those of speech or music-is called modulation. The first type of modulation developed was AM, or amplitude modulation, which Canadian-American physicist Reginald Aubrey Fessenden (1866-1932) demonstrated with the first United States radio broadcast in 1906. Amplitude modulation varies the instantaneous amplitude of the radio wave, a function of the radio stations power, as a means of transmitting information. By the end of World War I, radio had emerged as a popular mode of communication: for the first time in history, entire nations could hear the same sounds at the same time. During the 1930s, radio became increasingly important, both for entertainment and information. Families in the era of the Great Depression would gather around large cathedral radios-so named for their size and shape-to hear comedy programs, soap operas, news programs, and speeches by important public figures such as President Franklin D. Roosevelt. Throughout this era-indeed, for more than a half-century from the end of the first World War to the height of the Vietnam Conflict in the mid-1960s-AM held a dominant position in radio. This remained the case despite a number of limitations inherent in amplitude modulation: AM broadcasts flickered with popping noises from lightning, for instance, and cars with AM radios tended to lose their signal when going under a bridge. Yet, another mode of radio transmission was developed in the 1930s, thanks to American inventor and electrical engineer Edwin H. Armstrong (1890-1954). This was FM, or frequency modulation, which varied the radio signals frequency rather than its amplitude. Not only did FM offer a different type of modulation; it was on an entirely different frequency range. Whereas AM is an example of a long-wave radio transmission, FM is on the microwave sector of the electromagnetic spectrum, along with television and radar. Due to its high frequency and form of modulation, FM offered a clean sound as compared with AM. The addition of FM stereo broadcasts in the 1950s offered still further improvements; yet despite the advantages of FM, audiences were slow to change, and FM did not become popular until the mid-to late 1960s. SIGNAL PROPAGATION AM signals have much longer wavelengths, and smaller frequencies, than do FM signals, and this, in turn, affects the means by which AM signals are propagated. There are, of course, much longer radio wavelengths; hence, AM signals are described as intermediate in wavelength. These intermediate-wavelength signals reflect off highly charged layers in the ionosphere between 25 and 200 mi (40-332 km) above Earths surface. Short-wave-length signals, such as those of FM, on the other hand, follow a straight-line path. As a result, AM broadcasts extend much farther than FM, particularly at night. At a low level in the ionosphere is the D layer, created by the Sun when it is high in the sky. The D layer absorbs medium-wavelength signals during the day, and for this reason, AM signals do not travel far during daytime hours. After the Sun goes down, however, the D layer soon fades, and this makes it possible for AM signals to reflect off a much higher layer of the ionosphere known as the F layer. (This is also sometimes known as the Heaviside layer, or the Kennelly-Heaviside layer, after English physicist Oliver Heaviside and British-American electrical engineer Arthur Edwin Kennelly, who independently discovered the ionosphere in 1902.) AM signals bounce off the F layer as though it were a mirror, making it possible for a listener at night to pick up a signal from halfway across the country. The Sun has other effects on long-wave and intermediate-wave radio transmissions. Sunspots, or dark areas that appear on the Sun in cycles of about 11 years, can result in a heavier buildup of the ionosphere than normal, thus impeding radio-signal propagation. In addition, occasional bombardment of Earth by charged particles from the Sun can also disrupt transmissions. Due to the high frequencies of FM signals, these do not reflect off the ionosphere; instead, they are received as direct waves. For this reason, an FM station has a fairly short broadcast range, and this varies little with regard to day or night. The limited range of FM stations as compared to AM means that there is much less interference on the FM dial than for AM. In the United States and most other countries, one cannot simply broadcast at will; the airwaves are regulated, and, in America, the governing authority is the Federal Communications Commission (FCC). The FCC, established in 1934, was an outgrowth of the Federal Radio Commission, founded by Congress seven years earlier. The FCC actually sells air, charging companies a fee to gain rights to a certain frequency. Those companies may in turn sell that air to ot