Theory of Scaffolding Essays

Theory of Scaffolding Essays Theory of Scaffolding Essay Theory of Scaffolding Essay Theory of Scaffolding Literature around Scaffolding: There have been several discussions around scaffolding, in an attempt to define what it means for education. At the early stages of the theory of scaffolding, Wood, Bruner, and Ross (1976) explain the importance of the interactive, instructional relationship that tutors/teachershave in a learners development, supporting that the attendance of others is significant for scaffolding skills acquisition and problem solving. They also emphasize on the importance for realizing the value of a solution to generate the equence of steps that will lead to the solution of the problem, without scaffolding by an adult. As argued, this realization will result in effective feedback, as the learner will be able to value every step towards the solution, and therefore, in order for scaffolding to be effective the learner needs to generate solutions to the problem that are identifiable to them (Wood, Bruner, and Ross, 1976). However, in this scaffolding process, the tutor does not necessarily need to be a human; it can be a virtual, non- player character (NPC) as well. In this project, the scaffolding process takes place in the virtual environment of Quest Atlantis, where learners embark on a mission to resolve a problem, part of which requires the decryption of Mayan signs, and interpretation of them in English. The facilitators in this case are the NPCs that learners/players come across during their mission. A rich experience is what a leaner needs to develop to a knowledgeable individual, and the impact of the surrounding environment and the scaffolds in it are important for learning. Wgotsky (1978) has proposed that the learner needs to be scaffolded in rder to acquire all the skills that would have been difficult to acquire independently. The Wgotskian theoretical perspective holds that learners, and especially children can perform more challenging tasks when assisted, and that they can reach a high level of development (Zone of Proximal Development). According to Wgotsky, there are two aspects of learning development; the actual development and the potential development (Ugotsky, 1978). The Zone of Proximal Development (ZPD) is the distance between the actual development level, as determined by independent roblem solving and the level of potential development, as determined through problem solving under adult guidance, or in collaboration with more capable peers (Ugotsky, 1978, p. 86). Further, based on Wgotskys theory, the ZPD can also be defined as the area between what the learners can achieve by themselves, and what they can attain with the help of more knowledgeable individuals (Video 1). Therefore, meaningful learning is being enhanced in the learners ZPD, with the use of all the available scaffolds afforded by the surrounding environment. Scaffolds in the case of he virtual geocaching project are considered to be the mission page, NPCs, boxes with information, scrolls with information, translation tool, etc. Zone of Proximal Development and Scaffolding Video 1: A video about the Zone of Proximal Development and Scaffolding, describing Pea, in his commentary paper (2004, p. 31) discussed the role of fading in the scaffolding process, characterizing it as intrinsic to the scaffolding process. A scaffold used for the learner must be gradually removed during the learning process, until it is completely gone, and when the learner has reached the learning goal Collins, Brown, Newman, 1989). It is argued that, if the learning help is not being gradually removed, then the process is not called scaffolding anymore, but distributed intelligence, namely, intelligence that is a collective product, and where the individual does not internalize learning (Pea, 2004). Over time, there have been numerous software tools created to scaffold meaningful learning experiences, in and out of schools. Scaffolding is an inherent characteristic of games, either in virtual or in physical life. In the case of computer games, the scaffolds for performing a task are rovided to the player/learner in the virtual context, enhancing active participation. This project aims at exploring the potentials of scaffolding such rich experiences with the use of virtual tools. According to the sociocultural theoretical perspective, children must have time to practice roles and behaviors through play. Therefore, it treats the several gaming tasks and virtual tools as scaffolds for learning development. In a similar vein, Wgotsky argued that game play in general can offer scaffolding-rich experiences, as well as opportunities for a player to act a head above himself (Ugotsky, 1978, p. 4) extending their abilities in ways that would not be possible without play (Video 2). Fantasy play and learning- A Wgotskian approach Video 2: A Wgotskian approach to fantasy play and learning. The video provides a definition of scaffolding, describes the Zone of Proximal Development, as well as some practical perspectives on game play. Videogames, expertly craft ways of scaffolding support through what Gee (2003, p. 138) calls the explicit information on-demand and Just-in-time principle. Computer games host contexts that frame problems, or aspects of problems and learners ecome engaged in those situations, to form their understanding and contribute to a solution. In this case, learners use scaffolds in the frames of a situation, in a context (whether it is real or virtual) to make meaning of a situation, transfer learning across multiple gaming situations as well as real-life situations, participate actively to make a change in the context, and ultimately enhance learning effectively (Lave, 1988). In such gaming environments, transformational play unfolds around the notion of reflexive action (Barab et al. , 2009) where player must take the consequences of their ctions and choices in consideration. However, this consideration takes place in a context where the outcomes of choices do not affect players/learners in any way apart for their game play. Scaffolding Definition as given in a class about Designing Learning in Context: explicit and/or implicit knowledge that enables the learner to be able to successfully engage the activity with acceptable results while maintaining the learners substantive involvement. (Learner+Scafold+Task=Success). Implicit in the definition is that once the learner acquires the explicit and/or implicit knowledge the scaffold is o longer scaffolding. If the learner only acquires part of the knowledge associated with the scaffold, but still needs the scaffold in some different form or level, the process of changing the scaffold to the changing learner knowledge level is called fading. Implicit in the definition is that something is scaffolding only when engaged during the activity, not only before or only after. Scaffolding also promotes learning of required and unknown explicit and/or implicit knowledge of some aspect of the activity, but not necessarily learning of all aspects of knowledge related to every caffold at any give time. If scaffolding is not promoting any learning and still compensating for learners lack of explicit and/or implicit knowledge, then it is not scaffolding rather it is a permanent knowledge crutch. A permanent crutch undermines all activity related learning because there is no need to learn because the learner can successfully engage the activity with the permanent crutch. Individual scaffolds can completely compensate for learners lack of explicit and/or implicit knowledge, without promoting learning if the explicit and/or implicit nowledge related to other scaffolds are being learned. This is called a temporary knowledge crutch. A temporary crutch allows the learner the opportunity to learn in other areas of the activity. My approach to scaffolding: In this section I am providing my personal definition of scaffolding, as I perceive it, after intense thinking, and after a lot influence by several theorists that talked about scaffolding. This definition has derived from and matured thr ough my constant online and in-class discussions in the frames of a class on Designing Learning in Context: Scaffolding is a process through which an individual/learner moves from the supported to the independent level of learning. In this process there is an expert source that provides help/support to the learner, while engaging in the process of completing an activity. Throughout the scaffolding process there is also a plan/ strategy followed (scaffolding is intentional, and not a random process) by the expert source, as well as a plan/strategy for gradually removing the scaffold (fading), when the situation affords it. [1] A scaffold is one in the set of scaffolding and compensates for one aspect of a earners lack of explicit and/or implicit knowledge that enables the learner to successfully engage the activity with acceptable results. f required and unknown explicit and/or implicit knowledge of some aspect o e TeamView activity, but not necessarily learning of all aspects of knowledge related to ev compensating for learners lack of explicit and/or implicit knowledge, then it undermines all activity related learning because there is no need to learn be Individual scaffolds can completely compensate for learn ers lack of explicit a knowledge related to other scaffolds are being learned. This is called a tem knowledge crutch. A temporary crutch allows the learner the opportunity to In this section I am providing my personal definition of scaffolding, as I percei after intense thinking, and after a lot influence by several theorists that talk scaffolding. This definition has derived from and matured through my consta online and in-class discussions in the frames of a class on Designing Learni supported to the independent level of learning. In this process there is an ex source that provides help/support to the learner, while engaging in the proc completing an activity. Throughout the scaffolding process there is also a pla strategy followed (scaffolding is intentional, and not a random process) by th noAK_noqep Pa3pe naponb HeKOH- @ 3any npVlE ngu Ox 1Aap substantive involvement. (Learner+Scafold+Tasesuccess). Implicit in the definition is during the activity, not only before or only after. Scaffolding also promotes lea of required and unknown explicit and/or implicit knowledge of some aspect e TeamViev activity, but not necessarily learning of all aspects of knowledge related to e compensating for learners lack of explicit and/or implicit knowledge, then it i ndermines all activity related learning because there is no need to learn b Individual scaffolds can completely compensate for learners lack of explicit implicit knowledge, without promoting learning if the explicit and/or implici knowledge related to other scaffolds are being learned. This is called a te knowledge crutch. A temporary crutch allows the learner the opportunity t In this section I am providing my personal definition of scaffolding, as I per after intense thinking, and after a lot influence by several theorists that tal scaffolding. This definition has derived from and matured through my cons nline and in-class discussions in the frames of a class on Designing Learn Scaffolding is a process through which an individual/learner moves from th supported to the independent level of learning. In this process there is an e source that provides help/support to the learner, while engaging in the pro completing an activity. Throughout the scaffolding process there is also a pl Scenario Figure 1. Barn and Silos Third grade students in Mrs. Maddoxs class have been studying about different types of communities for the past two weeks. Throughout this study, students have ocused on distinguishing between rural, urban and suburban communities. Living in a rural community, students are familiar with large expanses of land, farms, considerable distances between houses, and lack of malls, skyscrapers and entertainment venues. In contrast with that, the students took a field trip to downtown Atlanta to experience tall buildings, public transportation, commuters, super highways, extensive shopping, sports arenas and fine arts venues. Through this trip, they came to have a better understanding of an urban community. Between the school and downtown Atlanta, students were exposed to suburban communities s the bus took them through a neighborhood and a community outside the perimeter. Students experienced rows of houses, commuters, strip malls, eating establishments, churches and parks. The students were better able to apply the knowledge of their classroom activities to the field trip and could easily determine the differences between each type of community. Figure 2. City and Tall Buildings As a culminating activity for this study on types of communities, the students are going to prepare some type of individually selected project demonstrating their knowledge of urban, suburban and rural communities. Mrs. Maddox makes suggestions as to the types of projects students might consider. Some choose to write and illustrate a book, others write and perform a play, and still others film a video each community. Patrick, the computer whiz of the class, decides to prepare a PowerPoint presentation which will incorporate digital pictures taken on the field trip and of the rural areas surrounding the school community. He has successfully written the text for his slides but has been unable to insert the digital pictures from his disk. Mrs. Maddox notices that Patrick is experiencing frustration with his inability o insert the pictures. She approaches to offer help, not to complete the task for Patrick, but rather to provide support and to help him achieve his objective on his Figure 3. Computer Mrs. Maddox thinks aloud as she offers help: Lets see. I want to insert a picture into the slide from the disk. I need to go to the toolbar at the top and select insert since thats what I want to do. And since its a picture that I want to insert, Ill select picture. Now I have to tell the computer where to find the picture I want. Since the picture is on a disk, Ill select from file. Then Ill click insert and viola My picture is there. Now all I have to do is save it. As Mrs. Maddox talks through the steps, Patrick carefully follows her prompts and completes each step. He beams as he sees the selected picture on his slide. Mrs. Maddox then teaches Patrick a chant she has composed that will assist him with the steps: In-sert a picture from a file; locate the file and se-lect the pic; click to in-sert and save it, quick! She watches as Patrick goes through the steps, questioning him with leading questions when he hesitates, and listens while he quietly says the chant to himself to perform the task. Again, he beams with excitement as the slide displays the selected picture. Mrs. Maddox moves away from the computer and allows Patrick to insert the next picture on his own. Seeing that he is successful, she moves on to assist another student. Later, when another student, Melissa, needs assistance with inserting a picture to a PowerPoint slide, Mrs. Maddox asks Patrick to be a peer tutor to her. He further expands his learning by explaining the steps to Melissa and by teaching her the same chant he used to complete the steps to insert a picture in the PowerPoint slide. Through her support and facilitation, Mrs. Maddox helped Patrick master a skill and achieve independence through carefully designed instruction called scaffolding. This process of scaffolding is much like the traditional definition of scaffolding as a temporary support system used until the task is complete and the building stands without support. Such is the concept of scaffolding. Immediate support is given to students in order to help them achieve skill or task independence. This assistance is a temporary framework provided by the teacher or a more knowledgeable person to ssist students in performing a task they otherwise cannot accomplish without assistance. Support is provided to the learner and then gradually removed so that the student can become a self-regulated, independent learner. Although the teacher assumes much of the control during scaffolded instruction, the ultimate goal of instruction is covert, independent self-regulatory learning (Ellis et al. 1994). Caption: In this animation, each box represents scaffolding provided by the teacher, and with each activity the level of learning goes up. The first box represents verbalizing

Grow Purple Chrome Alum Crystals - Simulated Amethyst

Grow Purple Chrome Alum Crystals - Simulated Amethyst Learn how to grow deep purple or lavender cubic crystals of potassium chromium sulfate dodecahydrate. In addition, you can grow clear crystals around the purple crystals, yielding a sparkling crystal with a purple core. The same technique can be applied to other crystal systems. What You Need: potassium chromium sulfate  (chromium alum)alumwaterclear glass jarstringcoffee filter or paper towelpencil, knife, or stick (to suspend string)spoon or stirring rod Time Required: days to months depending on the  desired size. Here's How: The growing solution will consist of a chromium alum solution mixed with an ordinary alum solution. Make a chromium alum solution by mixing 60 g of potassium chromium sulfate in 100 ml water (or 600 g chromium alum per liter of water).In a separate container, prepare a saturated solution of ordinary alum by stirring alum into warm water until it will no longer dissolve.Mix the two solutions in any proportion that you like. The more deeply colored solutions will produce darker crystals, but it will also be harder to monitor crystal growth.Grow a seed crystal using this solution, then tie it to a string and suspend the crystal in the remaining mixture.Loosely cover the container with a coffee filter or paper towel. At room temperature (~25 °C), the crystal can be grown via slow evaporation for as little time as a few days or as long as a few months.To grow a clear crystal over a colored core of this or any other colored alum, simply remove the crystal from the growing solution, allow it to dry, and then re-immerse it in a saturated solution of ordinary alum. Continue growth for as long as desired. Tips: A saturated solution of pure chrome alum will grow darker crystals, but the solution will be too dark to see through. Feel free to increase the concentration of chrome alum, but be aware that the solution becomes deeply colored.Notice that the chrome alum solution is a dark blue-green, but the crystals are purple!

McDonalds Business Case Study Example | Topics and Well Written Essays - 1750 words

McDonalds Business - Case Study Example With the growing public awareness and desire for socially responsible businesses, it is significant to note that companies consider planning for future socially responsible business operation (Kotler & Lee, 2004). An analysis on McDonald’s social responsibility evaluates an example of corporate social responsibility shown by McDonalds. McDonald is the largest company in the world that deals in hamburger food restaurants. In reference to McDonald’s corporate social responsibility, the company is taking action, maintaining openness in communication with its customers and shareholders and attaining results. The company works with its suppliers so as to promote socially responsible behaviors or practices in its supply chain as an integral part of the company’s supply chain strategy. This is part of the company’s social responsibility. In addition, the company has designed its own its code of conduct for suppliers which explains how the company desires or expec ts its suppliers to handle and treat their workers. The company has managed and succeeded in supporting suppliers who are removing sow gestation crates in supply chain. For instance, 50% of its Cargill contracted hog farms are all in new generation systems that do not apply gestation stalls for the benefit of the wider community. Additionally, McDonalds gives part of its pre-tax profits to corporate charity or philanthropy as part of its strategy to be socially responsible. The company conducts philanthropic contributions via the Ronald McDonald Houses Charities which focus to create, get and support programs that enhance and improve the well being and health of children in society. This body ensures that children in vulnerable communities can receive medication and dental treatment in order to improve their health and strengthen their respective families. This program aims to change and improve the lives of communities. As part of it being socially responsible, McDonalds has formul ated a way of engaging communities in operations through community based projects. Community based projects have become significant aspect of development assistance among world socially responsible organizations. For instance, McDonalds launched the Flagship farms initiative in Europe that aimed at employing innovative farming methods and practices across Europe and conducts research on how ethical farming practices can be included into commercial farming systems. Therefore, an economic relationship means a strategy of involving communities into business activity of the organization in order to makes sure that communities are embedded in corporate supply chain strategy so as to establish a sustainable business. Case study 2 McDonalds has got well written and designed corporate social responsibility program that it has well implemented in order to ensure that communities are integrated in its business and that it benefits from its business operation. For instance, the McDonald Compan y delivered its inaugural corporate social responsibility report in which the company sought to get extensive feedback from stakeholders and community. The company has included several things in its social responsible program that aim to make it more socially responsible. For instance, they have implemented program that aim to develop sustainable agriculture, employment policies

Can fossil fuel energy placed by nuclear energy Essay

Can fossil fuel energy placed by nuclear energy - Essay Example With this argument in mind, does this mean that nuclear energy is better than fossil fuel? The answer is a big NO. Nuclear energy is not a long term solution, nor is it a permanent answer for long term, safe energy source and I will analyze this based on safety, financial, environmental, and social impact of running nuclear power plants. According to World Nuclear Association (www.world-nuclear.org), nuclear power financially speaking is cost competitive with other forms of energy. This means that compared with gas and coal, nuclear power is cost competitive, unless of course there is direct access to low cost fossil fuel. Technically, because nuclear power would only rely on very little amount of uranium to produce tons of energy, there is the assumption that it is indeed cost efficient, especially in terms of long term solution. But think again, WNA is amenable that putting up a nuclear power plant has a â€Å"relatively high capital costs and the need to internalize all waste dis posal and decommissioning costs.† Ergo, though there is financial savings in the energy production itself, the costs goes on operations and maintenance of the plant. But there is more than just the financial economics of running nuclear power plant. A big issue is the health and safety risk.

Kampung Desa Essay Example for Free

Kampung Desa Essay Life was a bed of roses for the villagers of Kampung Desa until a gang of robbers had fled from a police station near the village recently. They were on the most wanted list by the police since they had harmed victims before. Ever since their getaway, there had been abundant of reports involving robbery occurring in Kampung Desa. Most victims were unable to identify the culprits because they were wearing masks. The villagers of Kampung Desa had been warned by the police to stay on guard at all times. The villagers were beginning to worry. Some of them immediately installed home security alarms and grille to protect their homes. Due to this alert, the chief of the village, Pak Ali, had to take quick actions. He had no idea what to do. But he cannot give up because there is more than one-way to skin a cat. He discussed with all the villagers and made a conclusion to carry out patrols, which will take effect the following night. In order for this plan to work out, they need to unite and fight those robbers together. The chief also advised all villagers to inform the authorities of suspicious activities happening in their village. see more:forgiveness is divine On that night, a whistle was blown to call the men in the village to assemble in front of Pak Ali’s house. He divided them into groups. Each group will be on guard according to their shifts. They were very enthusiastic and promised not to sleep on the job. The chief noticed the absence of Pak Said, the village’s foreman. He was puzzled. Pak Said never missed any of the village’s activities even if he was ill. Pak Said is known to be very industrious. Pak Ali went over to Pak Said’s house. It was as dark as a dungeon. Pak Ali man up and knocked on the door. Pak Said opened the door with a sour face. Pak Ali greeted him with a warm smile and asked why he did not join the night patrol. Pak Said furiously mocked the patrol by saying it was a waste of time and a wildcat scheme. Pak Ali was willing to compromise with him if he wanted an earlier shift. Of course, that made Pak Said even more enraged. Pak Ali explained that it would be unfair if he lets Pak Said slip away without any sensible reason because all the other men had participated. Pak Said proudly exclaimed that he has three strong sons to watch over his family through thick and thin. Then, he slammed the door before Pak Ali could say anything. Eventually, Pak Ali had to give up. But deep inside his heart, he scorned Pak Said. Who would have thought that his best friend would be so arrogant and self-centered? How could such a man feel no remorse? Nobody knew the robbers were lurking in the dead of the night behind Pak Said’s house. Just as Pak Ali left his house, the robbers were already eyeing on the unlocked door. Pak Said had forgotten to lock his front door after talking to Pak Ali. Pak Said, his wife and his three sons were already sailing in the sea of dreams. This gave an opportunity for the robbers to easily enter his house without anybody’s acknowledgement. Unfortunately, the robbers did not find any valuable goods in the living room, kitchen, dining room nor the storeroom. They were dissatisfied and decided to use force. The careless Pak Said did not lock his bedroom door either. This was indeed like a warm welcome to the robbers. They managed to tie up his wife. He quickly became aware of the robbers. Thanks to his spinal reflex, he bolted out of the room when he had the chance and deliberately ran into his sons’ room. His sons attempted to ambush the robbers. However, the robbers outnumbered them and hit them with a vase until they were knocked out. Pak Said was filled with terror after witnessing the apples of his eyes battered. He was on thin ice at that moment. He had no other choice than to call for help from the patrols. He was wiling to sacrifice his pride for the safe keep of his family’s lives. He screamed for help. To his disbelief, someone heard him and spontaneously blew a whistle. A crowd of people ran toward Pak Said’s house. The robber were frightened of getting caught, so they deserted their loot and hastily ran away but the crowd was able to seize them in the nick of time and tied them to a pole. A stitch in time saves nine. Those brutal robbers could have taken the lives of Pak Said’s family. The police department was straight away notified. Pak Said dashed out of his house and begged someone to call for an ambulance because his sons were severely injured. Pak Ali, whom he ridiculed, called an ambulance even after Pak Said bad-mouthed him earlier. Pak Said was in awe. He was ashamed of what he had said to Pak Ali. He apologised to Pak Ali and all the other villagers for what he had said about them. He should have think before he speaks. He now perceived the real meaning of unity and is forever in great debt for what the villagers had done for him. They all forgave him because to err is human and to forgive is divine.

Defining Personal Responsibility and Exploring My Own Responsibilities

What is personal responsibility? Some examples people would probably come up with would be these: working, chores, taking care of your family and some might even say going to school and getting a better education. The definition of personal responsibility is: the obligation to carry forward an assigned task to a successful conclusion. With responsibility goes authority to direct and take the necessary action to ensure success. ("DOD Dictionary of Military and Associated Terms"). Personal responsibility to me is taking ownership of the things that will affect us in anyway, whether it is in the long run or short term. If we do not take ownership of the situations around us we will be consumed by duties and assignments which at that point become a task and no longer just a responsibility. College is a personal responsibility to us all. In order to take control of our lives and have the options we desire, college is the avenue most of us will have to take. Successfully completing our studies and obtaining the highest level of education possible will open the doors to providing for those we care most about in our lives. It will allow us to live our dreams by having options to choose from, which is why we worked so hard and decided to go to school. According to "10 Incredibly Successful People Who Went To Community College" (2012), â€Å"Nolan D. Archibald who is the CEO and Chairman of Board of the Black & Decker Corporation, was once one of the youngest CEO of a Fortune 500 Company and has been celebrated by the American Marketing Association, Business week and Fortune as one of the most successful and ‘most wanted’ business executives in the country†¦Archibald graduated from Dixie Junior College† (7). The point is, it doesn’t m... ...e to use in any given situation. Works Cited 10 incredibly successful people who went to community college. (2012). Retrieved from http://www.onlineuniversities.com/blog/2010/01/10-incredibly-successful-people-who-went-to-community-college/ DOD Dictionary of Military and Associated terms. (). Retrieved from http://www.dtic.mil/doctrine/dod_dictionary/?zoom_query=responsibility&zoom_sort=0&zoom_per_page=10&zoom_and=1 Famous people & the schools they went to. (2012). Retrieved from http://www.collegecrunch.org/fun-stuff/famous-people-the-schools-they-went-to/ Julian, T., & Kominski, R. (2011, September). Education and Synthetic Work-Life Earnings Estimate. 2010 CENSUS, (), 2 Leading Thoughts. (2009). Retrieved from http://www.leadershipnow.com/responsibilityquotes.html Lincoln, A. (1862, December ). Message to Congress. Message to Congress, 10().

Importance of television in our life Essay

Natural rubber, also called India rubber or caoutchouc, as initially produced, consists of suitable polymers of the organic compound isoprene, with minor impurities of other organic compounds plus water. Forms of polyisoprene that are useful as natural rubbers are classified aselastomers. Currently, rubber is harvested mainly in the form of the latex from certain trees. The latex is a sticky, milky colloid drawn off by making incisions into the bark and collecting the fluid in vessels in a process called â€Å"tapping†. The latex then is refined into rubber ready for commercial processing. Natural rubber is used extensively in many applications and products, either alone or in combination with other materials. In most of its useful forms, it has a large stretch ratio, high resilience, and is extremely waterproof.[1] Varieties[edit] The major commercial source of natural rubber latex is the Parà ¡ rubber tree (Hevea brasiliensis), a member of the spurge family, Euphorbiaceae. This species is widely used because it grows well under cultivation and a properly managed tree responds to wounding by producing more latex for several years. Many other plants produce forms of latex rich in isoprene polymers, though not all produce usable forms of polymer as easily as the Parà ¡ rubber tree does; some of them require more elaborate processing to produce anything like usable rubber, and most are more difficult to tap. Some produce other desirable materials, for example gutta-percha (Palaquium gutta)[2] and chicle from Manilkara species. Others that have been commercially exploited, or at least have shown promise as sources of rubber, include the rubber fig (Ficus elastica), Panama rubber tree (Castilla elastica), various spurges (Euphorbia spp.), lettuce (Lactuca species), the related Scorzonera tau-saghyz, various Taraxacum species, including common dandelion (Taraxacum officinale) and Russian dandelion (Taraxacum kok-saghyz), and guayule (Parthenium argentatum). The term gum rubber is sometimes applied to the tree-obtained version of natural rubber in order to distinguish it from the synthetic version.[1] Discovery of commercial potential[edit] The Para rubber tree is indigenous to South America. Charles Marie de La Condamine is credited with introducing samples of rubber to the Acadà ©mie Royale des Sciences of France in 1736.[3] In 1751, he presented a paper by Franà §ois Fresneau to the Acadà ©mie (eventually published in 1755) which described many of the properties of rubber. This has been referred to as the first scientific paper on rubber.[3] In England, Joseph Priestley, in 1770, observed that a piece of the material was extremely good for rubbing off pencil marks on paper, hence the name â€Å"rubber†. Later, it slowly made its way around England. South America remained the main source of the limited amounts of latex rubber used during much of the 19th century. In 1876, Henry Wickham gathered thousands of Para rubber tree seeds from Brazil, and these were germinated in Kew Gardens, England. The seedlings were then sent to India, Ceylon (Sri Lanka), Indonesia, Singapore, and British Malaya. Malaya (now Malaysia) was later to become the biggest producer of rubber. In the early 1900s, the Congo Free State in Africa was also a significant source of natural rubber latex, mostly gathered by forced labor. Liberia and Nigeria also started production of rubber. In India, commercial cultivation of natural rubber was introduced by the British planters, although the experimental efforts to grow rubber on a commercial scale in India were initiated as early as 1873 at the Botanical Gardens, Calcutta. The first commercial Hevea plantations in India were established at Thattekadu in Kerala in 1902. In Singapore and Malaya, commercial production of rubber was heavily promoted by Sir Henry Nicholas Ridley, who served as the first Scientific Director of the Singapore Botanic Gardens from 1888 to 1911. He distributed rubber seeds to many planters and developed the first technique for tapping trees for latex without causing serious harm to the tree.[4]Because of his very fervent promotion of this crop, he is popularly remembered by the nickname â€Å"Mad Ridley†.[5] Properties[edit] Rubber latex Rubber exhibits unique physical and chemical properties. Rubber’s stress-strain behavior exhibits the Mullins effect and the Payne effect, and is often modeled as hyperelastic. Rubber strain crystallizes. Owing to the presence of a double bond in each repeat unit, natural rubber is susceptible to vulcanisation and sensitive to ozone cracking. The two main solvents for rubber are turpentine and naphtha (petroleum). The former has been in use since 1764 when Franà §ois Fresnau made the discovery. Giovanni Fabbroni is credited with the discovery of naphtha as a rubber solvent in 1779. Because rubber does not dissolve easily, the material is finely divided by shredding prior to its immersion. An ammonia solution can be used to prevent the coagulation of raw latex while it is being transported from its collection site. Elasticity[edit] In most elastic materials, such as metals used in springs, the elastic behavior is caused by bond distortions. When force is applied, bond lengths deviate from the (minimum energy) equilibrium and strain energy is stored electrostatically. Rubber is often assumed to behave in the same way, but this is a poor description. Rubber is a curious material because, unlike in metals, strain energy is stored thermally. In its relaxed state, rubber consists of long, coiled-up chains. When rubber is stretched, the chains are taut. Their kinetic energy is released as heat. The entropy and temperature increases during elongation but decreases during relaxation. This change in entropy is related to the changes in degrees of freedom. Relaxation of a stretched rubber band is thus driven by a decrease in entropy and temperature, and the force experienced is a result of the cooling of the material being converted to potential energy. Rubber relaxation isendothermic, and for this reason the force exerted by a stretched piece of rubber increases with temperature. The material undergoes adiabatic cooling during contraction. This property of rubber can easily be verified by holding a stretched rubber band to one’s lips and relaxing it. Stretching of a rubber band is in some ways opposite to compression(although both undergo higher levels of thermal energy of an ideal gas), and relaxation is opposed to gas expansion (Note: rubber bands last longer in the cold). A compressed and heated gas also exhibits â€Å"elastic† properties, for instance inside an inflated car tire. The fact that stretching is equivalent to compression is counterintuitive, but it makes sense if rubber is viewed as a one-dimensional gas, plus it is attached to other molecules. Stretching and heat increase the â€Å"space† available to each section of chain, because the molecules are pulled apart. Vulcanization of rubber creates disulfide bonds between chains, so it limits the degrees of freedom. The result is that the chains tighten more quickly for a given strain, thereby increasing the elastic force constant and making rubber harder and less extensible. When cooled below the glass transition temperature, the quasifluid chain segments â€Å"freeze† into fixed geometries and the rubber abruptly loses its elastic properties, although the process is reversible. This property it shared by most elastomers. At very low temperatures, rubber is rather brittle. This critical temperature is the reason winter tires use a softer version of rubber than normal tires. The failing rubber o-ring seals that contributed to the cause of the Challenger disaster were thought to have cooled below their critical temperature; the disaster happened on an unusually cold day. The gas molecules in the rubber were too close to their bound solid molecules(a partial phase change that separated the rubber molecules may have occurred), allowing the rubber to take on a more solid shape(a partial phase change to a more liquid and molecularly separated form would not be good, either). Heated gas has a higher energy, and rubber must be kept at specific temperatures and probably should not be used on vehicles that undergo extreme temperature changes. Chemical makeup[edit] Latex is the polymer cis-1,4-polyisoprene – with a molecular weight of 100,000 to 1,000,000 daltons. Typically, a small percentage (up to 5% of dry mass) of other materials, such as proteins, fatty acids, resins, and inorganic materials (salts) are found in natural rubber. Polyisoprene can also be created synthetically, producing what is sometimes referred to as â€Å"synthetic natural rubber†, but the synthetic and natural routes are completely different.[1] Chemical structure of cis-polyisoprene, the main constituent of natural rubber: Synthetic cis-polyisoprene and natural cis-polyisoprene are derived from different precursors. Some natural rubber sources, such as gutta-percha, are composed of trans-1,4-polyisoprene, a structural isomer that has similar, but not identical, properties. Natural rubber is an elastomer and a thermoplastic. Once the rubber is vulcanized, it will turn into a thermoset. Most rubber in everyday use is vulcanized to a point where it shares properties of both; i.e., if it is heated and cooled, it is degraded but not destroyed. The final properties of a rubber item depend not just on the polymer, but also on modifiers and fillers, such as carbon black, factice, whiting, and a host of others. Biosynthesis[edit] Rubber particles are formed in the cytoplasm of specialized latex-producing cells called laticifers within rubber plants.[6] Rubber particles are surrounded by a single phospholipid membrane with hydrophobic tails pointed inward. The membrane allows biosynthetic proteins to be sequestered at the surface of the growing rubber particle, which allows new monomeric units to be added from outside the biomembrane, but within the lacticifer. The rubber particle is an enzymatically active entity that contains three layers of material, the rubber particle, a biomembrane, and free monomeric units. The biomembrane is held tightly to the rubber core due to the high negative charge along the double bonds of the rubber polymer backbone.[7] Free monomeric units and conjugated proteins make up the outer layer. The rubber precursor is isopentenyl pyrophosphate (an allylic compound), which elongates by Mg2+-dependent condensation by the action of rubber transferase. The monomer adds to the pyrophosphate end of the growing polymer.[8] The process displaces the terminal high-energy pyrophosphate. The reaction produces a cis polymer. The initiation step is catalyzed by prenyltransferase, which converts three monomers of isopentenyl pyrophosphate into farnesyl pyrophosphate.[9] The farnesyl pyrophosphate can bind to rubber transferase to elongate a new rubber polymer. The required isopentenyl pyrophosphate is obtained from the mevalonate pathway, which is derives from acetyl-CoA in the cytosol. In plants, isoprene pyrophosphate can also be obtained from 1-deox-D-xyulose-5-phosphate/2-C-methyl-D-erythritol-4-phosphate pathway within plasmids.[10] The relative ratio of the farnesyl pyrophosphate initiator unit and isoprenyl pyrophosphate elongation monomer determines the rate of new particle synthesis versus elongation of existing particles. Though rubber is known to be produced by only one enzyme, extracts of latex have shown numerous small molecular weight proteins with unknown function. The proteins possibly serve as cofactors, as the synthetic rate decreases with complete removal.[11] Current sources[edit] Close to 21 million tons of rubber were produced in 2005, of which approximately 42% was natural. Since the bulk of the rubber produced is of the synthetic variety, which is derived from petroleum, the price of natural rubber is determined, to a large extent, by the prevailing global price of crude oil.[12][13] Today, Asia is the main source of natural rubber, accounting for about 94% of output in 2005. The three largest producing countries, Thailand, Indonesia (2.4m tons)[14] and Malaysia, together account for around 72% of all natural rubber production. Natural rubber is not cultivated widely in its native continent of South America due to the existence of South American leaf blight, and other natural predators of the rubber tree. Cultivation[edit] Rubber is generally cultivated in large plantations. See the coconut shell used in collecting latex, in plantations in Kerala, India Rubber latex is extracted from rubber trees. The economic life period of rubber trees in plantations is around 32 years – up to 7 years of immature phase and about 25 years of productive phase. The soil requirement of the plant is generally well-drained, weathered soil consisting of laterite, lateritic types, sedimentary types, nonlateritic red, or alluvial soils. The climatic conditions for optimum growth of rubber trees are: Rainfall of around 250 cm evenly distributed without any marked dry season and with at least 100 rainy days per year Temperature range of about 20 to 34 °C, with a monthly mean of 25 to 28 °C High atmospheric humidity of around 80% Bright sunshine amounting to about 2000 hours per year at the rate of six hours per day throughout the year Absence of strong winds Many high-yielding clones have been developed for commercial planting. These clones yield more than 2,000 kg of dry rubber per hectare per year, when grown under ideal conditions. Field coagula[edit] Mixed field coagula Smallholder’s lump at a remilling factory There are four types of field coagula, â€Å"cuplump†, â€Å"treelace†, â€Å"smallholders’ lump† and â€Å"earth scrap†. Each has significantly different properties.[15] Cuplump is the coagulated material found in the collection cup when the tapper next visits the tree to tap it again. It arises from latex clinging to the walls of the cup after the latex was last poured into the bucket, and from late-dripping latex exuded before the latex-carrying vessels of the tree become blocked. It is of higher purity and of greater value than the other three types. Treelace is the coagulum strip that the tapper peels off the previous cut before making a new cut. It usually has higher copper and manganese contents than cuplump. Both copper and manganese are pro-oxidants and can lower the physical properties of the dry rubber. Smallholders’ lump is produced by smallholders who collect rubber from trees a long way away from the nearest factory. Many Indonesian smallholders, who grow paddy in remote areas, tap dispersed trees on their way to work in the paddy fields and collect the latex (or the coagulated latex) on their way home. As it is often impossible to preserve the latex sufficiently to get it to a factory that processes latex in time for it to be used to make high quality products, and as the latex would anyway have coagulated by the time it reached the factory, the smallholder will coagulate it by any means available, in any container available. Some smallholders use small containers, buckets etc., but often the latex is coagulated in holes in the ground, which are usually (but not always) lined with plastic. Acidic materials and fermented fruit juices are used to coagulate the latex – a form of assisted biological coagulation. Little care is taken to exclude twigs, leaves, and even bark from the lumps that are formed, which may also include treelace collected by the smallholder. Earth scrap is the material that gathers around the base of the tree. It arises from latex overflowing from the cut and running down the bark of the tree, from rain flooding a collection cup containing latex, and from spillage from tappers’ buckets during collection. It contains soil and other contaminants, and has variable rubber content depending on the amount of contaminants mixed with it. Earth scrap is collected by the field workers two or three times a year and may be cleaned in a scrap-washer to recover the rubber, or sold off to a contractor who will clean it and recover the rubber. It is of very low quality and under no circumstances should it be included in block rubber or brown crepe. Processing[edit] Removing coagulum from coagulating troughs The latex will coagulate in the cups if kept for long. The latex has to be collected before coagulation. The collected latex, â€Å"field latex†, is transferred into coagulation tanks for the preparation of dry rubber or transferred into air-tight containers with sieving for ammoniation. Ammoniation is necessary to preserve the latex in colloidal state for long. Latex is generally processed into either latex concentrate for manufacture of dipped goods or it can be coagulated under controlled, clean conditions using formic acid. The coagulated latex can then be processed into the higher-grade, technically specified block rubbers such as SVR 3L or SVR CV or used to produce Ribbed Smoke Sheet grades. Naturally coagulated rubber (cup lump) is used in the manufacture of TSR10 and TSR20 grade rubbers. The processing of the rubber for these grades is a size reduction and cleaning process to remove contamination and prepare the material for the final stage of drying.[16] The dried material is then baled and palletized for storage and shipment in various methods of transportation. Transportation[edit] Natural rubber latex is shipped from factories in south-west Asia, South America, and North Africa to destinations around the world. As the cost of natural rubber has risen significantly, the shipping methods which offer the lowest cost per unit of weight are preferred. Depending on the destination, warehouse availability, and transportation conditions, some methods are more suitable to certain buyers than others. In international trade, latex rubber is mostly shipped in 20-foot ocean containers. Inside the ocean container, various types of smaller containers are used by factories to store latex rubber.[17] Uses[edit] Compression molded (cured)rubber boots before the flashesare removed Contemporary manufacturing[edit] Around 25 million tonnes of rubber is produced each year, of which 42 percent is natural rubber. The remainder is synthetic rubber derived from petrochemical sources. Around 70 percent of the world’s natural rubber is used in tires. The top end of latex production results in latex products such as surgeons’ gloves, condoms, balloons and other relatively high-value products. The mid-range which comes from the technically-specified natural rubber materials ends up largely in tires but also in conveyor belts, marine products and miscellaneous rubber goods. Natural rubber offers good elasticity, while synthetic materials tend to offer better resistance to environmental factors such as oils, temperature, chemicals or ultraviolet light and suchlike. â€Å"Cured rubber† is rubber which has been compounded and subjected to the vulcanisation process which creates cross-links within the rubber matrix. Prehistoric uses[edit] The first use of rubber was by the Olmecs, who centuries later passed on the knowledge of natural latex from the Hevea tree in 1600 BC to the ancient Mayans. They boiled the harvested latex to make a ball for a Mesoamerican ballgame.[18] Pre-World War II manufacturing[edit] Other significant uses of rubber are door and window profiles, hoses, belts, gaskets, matting, flooring, and dampeners (antivibration mounts) for the automotive industry. Gloves (medical, household and industrial) and toy balloons are also large consumers of rubber, although the type of rubber used is concentrated latex. Significant tonnage of rubber is used as adhesives in many manufacturing industries and products, although the two most noticeable are thepaper and the carpet industries. Rubber is also commonly used to make rubber bands and pencil erasers. Pre-World War II textile applications[edit] Rubber produced as a fiber, sometimes called ‘elastic’, has significant value for use in the textile industry because of its excellent elongation and recovery properties. For these purposes, manufactured rubber fiber is made as either an extruded round fiber or rectangular fibers that are cut into strips from extruded film. Because of its low dye acceptance, feel and appearance, the rubber fiber is either covered by yarn of another fiber or directly woven with other yarns into the fabric. In the early 1900s, for example, rubber yarns were used in foundation garments. While rubber is still used in textile manufacturing, its low tenacity limits its use in lightweight garments because latex lacks resistance to oxidizing agents and is damaged by aging, sunlight, oil, and perspiration. Seeking a way to address these shortcomings, the textile industry has turned to neoprene (polymer of chloroprene), a type of synthetic rubber, as well as another more commonly used elastomer fiber, spandex (also known as elastane), because of their superiority to rubber in both strength and durability. Vulcanization[edit] Main article: Vulcanization Natural rubber is often vulcanized, a process by which the rubber is heated and sulfur, peroxide or bisphenol are added to improve resistance and elasticity, and to prevent it from perishing. The development of vulcanization is most closely associated with Charles Goodyear in 1839.[19] Before World War II era manufacturing, carbon black was often used as an additive to rubber to improve its strength, especially in vehicle tires. Today, all vehicle tires are made of synthetic rubbers. Allergic reactions[edit] Main article: Latex allergy Some people have a serious latex allergy, and exposure to natural latex rubber products such as latex gloves can cause anaphylactic shock. The antigenic proteins found in Hevealatex may be deliberately reduced (though not eliminated)[20] through processing. Latex from non-Hevea sources, such as Guayule, can be used without allergic reaction by persons with an allergy to Hevea latex.[21] Some allergic reactions are not to the latex itself, but from residues of chemicals used to accelerate the cross-linking process. Although this may be confused with an allergy to latex, it is distinct from it, typically taking the form of Type IV hypersensitivity in the presence of traces of specific processing chemicals.[20][22]

Why Did Americans Pass the 1882 Chinese Exclusion Act?

During the late 1800s, The Gilden Age was in full effect. After the Decade of Crisis, when thousands of settlers came to the West in search of gold, reconstruction began. While many of these temporary settlers left when the Gold Rush was over, some stayed like the Chinese.They worked on the Transcontinental Railroad, more commonly as replacements for fellow Irishmen, Germans, Englishmen, or Italians who were unreliable for miscellaneous reasons. Tensions rose between the two groups once the railroad was finished in 1869. By 1878, courts ruled that any Chinese man couldn't be naturalized.Americans then passed the Chinese Exclusion Act in 1882 which denied all Chinese the right to American citizenship, even those born in the United States. Americans passed the Chinese Exclusion Act because they resented the competition for work, they had stereotypical hatred toward the Chinese, and they felt exclusion was the Chinese's only protection.Americans passed the Chinese Exclusion Act because they resented the competition for work. When approximately 25,000 Chinese had immigrated to America, about 15,000 of them were employed by the Central Pacific Railroad.After the railroad was finished, many Chinese continued to find work elsewhere within the West. â€Å"Today, every avenue of labor, of every sort, is crowded with Chinese slave labor worse than it was eight years ago. The boot, shoe, and cigar industries are almost entirely in their hands†¦They monopolize nearly all the farming done to supply the market with all sorts of vegetables† (Doc C). After the Fourteenth Amendment was passed, slavery was no longer an issue in all U. S. territories, although Americans saw Chinese labor equivalent to the same threatening competition of slavery from the early 1800s.The Chinese argued that their work was fair, hard, and respectable work that had no resemblance to slavery, and demanded a high market price. â€Å"No one would hire an Irishman, German, Englishman, or Ita lian when he could get a Chinese, because our countrymen are so much more honest, industrious, steady, sober, and painstaking† (Doc D).Americans denied Chinese citizenship and lives in the United States is mere fear of their virtues which were mistaken as vices. Americans passed the Chinese Exclusion Act because they had stereotypical hatred toward Chinese.Many Americans saw the Chinese as pseudo-men, they were short and small with ponytails. The Chinese were also underestimated and seen as uneducated. Document A: Anti-Chinese Play, 1879, The Chinese Must Go, states that a Chinese man thinks white men are foolish for having families and less money for themselves. This document fails to mention that Chinese women were banned from immigrating to the U. S. in 1870, then courts preventing Chinese workers to have families in the America once interracial marriage was banned later on in 1879.Document A also says that a Chinese man reminds Frank B. of his mother's debt of six dollars to himself. In reality, no uneducated man would so boldly denounce their employer for pay, let alone know how much from what month. Not only were the Chinese killed and discriminated against in anti-Chinese violence through your the late 1800s, but America's courts made it nearly impossible for them to pursue happiness. The Chinese Exclusion Act only made this hatred more apparent. Americans passed the Chinese Exclusion Act because they felt that exclusion was the only protection for the Chinese.Within one year of the act being passed the Chinese immigration dropped from 40,000 to 23,000. This difference smoothed out a lot of heat between Americans and Chinese because there were less Chinese â€Å"flocking into our States† (Doc C).Even the Chinese felt the resentment once they were denied any sort of naturalized or natural born citizenship. â€Å"More than half the Chinese in this country would become citizens if allowed to do so, and would be patriotic Americans. But how ca n they make this country their home as matters now are! †¦Under the circumstances, how can I call this my home, and how can any one blame me if I take my money and go back to my village in China? † (Doc D). The Chinese felt more comfortable and protected going back to their homes across the pond than what homes they made in the United States through hard work and opportunity.Document B illustrates Columbia, America's feminine symbol, standing between a group of aggressive Irish and German thugs and a lonely Chinese man who seems to have done nothing to provoke them, other than being Chinese.Artist, Thomas Nast portrays that not only is America trying to stop the anti-Chinese violence, but that the only way the Chinese can protected and safe is separated from the people of America. The Chinese were victims of the later 19th century, who were persecuted for their virtues, not their vices.Americans banned any sort of legal citizenship and immigration to appease the jealous s ociety of the West. The Chinese Exclusion Act was passed because the ignorant and judgmental Americans hated to see someone else do what they did with better ethics and spirits, therefore their aggressive acts resulted in racial exclusion.

obsessive compulsive behaviour essays

obsessive compulsive behaviour essays Websters dictionary defines a hero as a mythological or legendary figure often of divine descent endowed with great strength or ability, an illustrious warrior, a man admired for his achievements and noble qualities, and one that shows great courage. In the book The Time Machine, the hero is the traveler. He is not only ambitious, but he is also courageous. He faces many difficult situations which using his brilliance, his vast amounts of knowledge and his will to survive is able to cheat death on many occasions. His friends all look up to him, and admire his radiance. The traveler survived more than any average man would have ever been able to endure. One would be amazed to see the time line which the traveler had spent over his highly adventurous eight days. He not only sacrificed himself physically, he was also on the brink of insanity. With his highly advanced knowledge of science and mathematics, he was able to not only stay aware of his position, but he stayed on top of his problems. His ambition carried him farther than any other emotion ever could have. His courage allowed for his exploratory searches of the new world. It helped him get as far as it did. Without it, he probably would have been killed very early into his quest. On many occasions the traveler explains his willingness to gain more and more knowledge, I have thought since how particularly ill-equipped I was for such an experience. When I had started with the time machine, I had started with the assumption that the men of the future would certainly be infinitely ahead of our selves in all their appliances. I had come without arms, without medicine, without anything to smoke at times I missed tobacco frightfully even without enough matches. If only I had a glimpse of the Underworld in a second, and examined it at leisure (page 70). This quote clearly allows us to see how the traveler,...

Licencia de conducir para indocumentados en Maryland

Licencia de conducir para indocumentados en Maryland El estado de Maryland permite a los migrantes indocumentados obtener la licencia de manejar o, para los que no desean conducir, una tarjeta de identificacià ³n conocida o  I.D.  por sus siglas en inglà ©s. En este artà ­culo se informa sobre quà © pasos hay que seguir para solicitar la licencia y quà © documentos es necesario presentar. Asimismo, se habla de cà ³mo es la situacià ³n en otros estados y cul es el estatus particular de los muchachos indocumentados que se conoce como Dreamers, ya que para ellos el tema de licencia de manejar opera de otra forma. Cà ³mo sacar la licencia de manejaro I.D. en Maryland si se est como indocumentado Estos son los requisitos que hay que cumplir y la documentacià ³n que hay que colectar antes de examinarse de conducir: Prueba de haber pagado los impuestos (taxes) en el estado de Maryland por al menos 2 aà ±os.Un nà ºmero fiscal que se conoce como ITIN y que se solicita al IRS.Una carta certificada por la Oficina del Controlador de Maryland que puede solicitarse por internet.Un I.D. vlido y sin expirar, por ejemplo, el pasaporte o matrà ­cula consular.2 documentos que sirvan para probar residencia en el estado de Maryland como por ejemplo el lease de la vivienda, las facturas del pago del telà ©fono, cable, electricidad, extractos bancarios, etc.   Si no se tienen todos los documentos no se puede obtener ni el I.D. ni la licencia de manejar de autos o para bicimotos. Si la intencià ³n es solamente obtener un I.D. del estado, lo anterior es suficiente y ya se puede cerrar una cita con el Department of Motor Vehicles. Por el contrario,  si adems se quiere obtener la licencia de manejar entonces hay que tomar los tests. Exmenes para la licencia de manejar en Maryland El primer paso es estudiar el manual del conductor para autos y bicimotos. Se pueden tomar gratuitamente tests por internet para asegurarse que se sabe la respuesta.   Despuà ©s cerrar una cita para rendir el examen de conocimientos y posteriormente tomar el test de manejar. Para esto à ºltimo pueden darse dos situaciones: Si ya se tiene una licencia de manejar de otro paà ­s sin expirar y vigente entonces es necesario tomar una leccià ³n de tres horas sobre un Programa de Educacià ³n de Drogas y Alcohol y luego ya ser posible tomar el examen de manejar.Por el contrario, si no se tiene ese tipo de licencia es necesario sacar primero un Permiso de Estudiante, lo que en inglà ©s se conoce como Learner ´s Permit, y tambià ©n tomar un curso de Educacià ³n para Conductores. Sà ³lo luego despuà ©s se puede tomar el examen de conducir. Atentos para evitar estafas No es posible comprar la licencia de manejar. Mucho cuidado con las personas que aseguran que pueden obtener uno a cambio de una cantidad de dinero.   Los casos de fraudes a inmigrantes se pueden denunciar, aà ºn cuando se tenga estatus de inmigrante indocumentado. Pero en la situacià ³n actual es siempre mejor consultar primero con un abogado o una organizacià ³n de ayuda a los migrantes. Cà ³mo son las leyes en otros estados y Dreamers Estos son los estados en los que los indocumentados pueden sacar la licencia de manejar. Tener en cuenta que los Dreamers con la Accià ³n Diferida aprobada se rigen por otras reglas y pueden obtener sus licencias de la forma regular que aplican a los ciudadanos americanos y residentes permanentes legales. En otras palabras, pueden manejar en todos los estados. Derechos de los indocumentados Aunque seas indocumentado por ley tienes derecho a cobrar al menos el salario mà ­nimo, que varà ­a de estado a estado. En cuanto al tema de la legalizacià ³n en la actualidad existen  15 posibles caminos que existen en la actualidad para la regularizacià ³n de indocumentados. Hay que tener en cuenta que no es fcil y que depende de las circunstancias de cada uno. Si se cree que se puede calificar para alguna de ellas, es fundamental contar con un buen abogado migratorio que conozca las leyes a fondo y se conduzca con à ©tica. Si no se conoce, se recomienda pedir asesoramiento para elegir abogado a instituciones reputadas con buenas bases de datos. Finalmente, como asunto prctico destacar los  Ã‚  documentos que sirven para viajar por avià ³n dentro de Estados Unidos, ya que este es un asunto que preocupa especialmente a los migrantes indocumentados.

Laboratory report on sluice gate and hydraulic jump Coursework

Laboratory report on sluice gate and hydraulic jump - Coursework Example Generally, sluice gats are made up of a gate, a power mechanism and a frame and they are designed to withstand various water loads at different operating heights. There are two types of sluice gates. These are the wall-mounted sluice gates and the vertical rising sluice gates. For the vertical rising sluice gates, they are designed such that water flow is prevented as long as the water height does not exceed the gate height. In this types of sluice gates, the bottom and the side walls are sealed. For the wall-mounted sluice gates, also referred to as bottom sluice gates, passage of water is prevented to flow up to heights that exceed the gate. In this type, all the four sides of the sluice gates are sealed (Hager, 1992). As water flows in an open channel, it is only acted upon by atmospheric pressure implying that the gauge pressure is zero. In open channel flow, two flow depths exists, these are the subcritical flow and the supercritical flow (Khatsuria, 2004). The use of sluice in open channel alters the flow characteristics resulting in the flow changing from subcritical to supercritical. The flow rate under a sluice gate is illustrated by equation (1) below where by it is assumed that the flow is ideal (which is never the case in real situation). From the figure 1 above, it can be seen that flow under the sluice gate results into generation of a hydraulic jump just before the flow resumes back to subcritical flow from supercritical flow (Subramanya, 2009). As earlier connoted, a sluice gate changes flow from subcritical to supercritical flow. Under normal cases, the flow in an open channel is usually subcritical, therefore as the flow reverts back to sub-critical flow after passing through a sluice gate, there is sudden energy dissipation that results from the change of flow from supercritical to subcritical (Hager, 1992). This is the hydraulic jump. Where V is the velocity, is the

Oreos Advertising With Breastfeeding Essay Example | Topics and Well Written Essays - 500 words

Oreos Advertising With Breastfeeding - Essay Example In fact, this is the practice that should be promoted because babies are now being bottle fed where they do not get all the nutrients they need. It only portrayed an idealized reality that babies should be breast fed and that there is nothing wrong with the image of a baby being nursed by his or her mother. It made a big difference when the ad was created by a reputable agency such as Cheil Worldwide because the ad was taken seriously and cannot be easily dismissed. Especially when it was shown during awards gathering in South Korea where it becomes credible and reputable. It may be controversial but it cannot be readily dismissed as something obscene or improper because the ad was created by an advertising agency composed of professionals trained and educated in advertising. This made the people looked at the message of the ad closely that breastfeeding mothers liked the message. The creator Cheil Worldwide put ethos or credibility to the ad for it to be taken seriously and not be e asily dismissed. The effective use of rhetorical devices such as pathos (emotional appeal), logos (logical appeal) and ethos (credibility) made the Oreo advertisement powerful that it stirred controversy. In fact, the attention was drawn away from the cookie that image intends to advertise but instead, the focus was centered on the image. It is so powerful that it even raised awareness about breastfeeding and was suddenly transformed from merely an advertisement that intends to sell cookies to an advocacy material for breastfeeding.