Biography of Eratosthenes, Greek Geographer

Eratosthenes of Cyrene (c. 276 BCE–192 or 194 BCE) was an ancient Greek mathematician, poet, and astronomer who is known as the father of geography. Eratosthenes was the first person to use the word geography and other geographical terms that are still in use today, and his efforts to calculate the circumference of the Earth and the distance from the Earth to the Sun paved the way for our modern understanding of the cosmos. Among his other many accomplishments were the creation of the first map of the world and the invention of an algorithm known as the sieve of Eratosthenes, which is used to identify prime numbers. Fast Facts: Eratosthenes Known For: Eratosthenes was a Greek polymath who became known as the father of geography.Born: c. 276 BCE in Cyrene (present-day Libya)Died: 192 or 196 BCE in Alexandria, Egypt Early Life Eratosthenes was born around 276 BCE in a Greek colony in Cyrene, a territory located in present-day Libya. He was educated at the academies of Athens and in 245 BCE, after earning attention for his skills, he was invited by Pharaoh Ptolemy III to run the Great Library at Alexandria in Egypt. This was a major opportunity, and Eratosthenes was excited to accept the position. In addition to being a mathematician and geographer, Eratosthenes was also a very gifted philosopher, poet, astronomer, and music theorist. He made several significant contributions to science, including the discovery that a year is slightly longer than 365 days, requiring an extra day—or leap day—be added to the calendar every four years to keep it consistent. Geography While serving as the head librarian and scholar at the Library of Alexandria, Eratosthenes wrote a comprehensive treatise about the world, which he called Geography. This was the first use of the word, which in Greek means writing about the world. Eratosthenes work introduced the concepts of torrid, temperate, and frigid climate zones. His map of the world, though highly inaccurate, was the first of its kind, featuring a grid of parallels and meridians used to estimate distances between different locations. Though Eratosthenes original Geography did not survive, modern scholars know what it contained thanks to reports by Greek and Roman historians. The first book of Geography contained a summary of existing geographical work and Eratosthenes speculations about the nature of the planet Earth. He believed it was a fixed globe whose changes only took place on the surface. The second book of Geography described the mathematical calculations he had used to determine the circumference of the Earth. The third contained a map of the world in which the land was divided into different countries; it is one of the earliest examples of political geography. Calculating the Circumference of the Earth Eratosthenes most famous contribution to science was his calculation of the circumference of the Earth, which he completed while working on the second volume of his Geography. After hearing about a deep well at Syene (near the Tropic of Cancer and modern-day Aswan) where sunlight only struck the bottom of the well on the summer solstice, Eratosthenes worked out a method by which he could calculate the circumference of the Earth using basic geometry. Knowing that the Earth was a sphere, he needed only two critical measurements to calculate the circumference. Eratosthenes already knew the approximate distance between Syene and Alexandria, as measured by camel-powered trade caravans. He then measured the angle of the shadow in Alexandria on the solstice. By taking the angle of the shadow (7.2 degrees) and dividing it into the 360 degrees of a circle (360 divided by 7.2 yields 50), Eratosthenes could then multiply the distance between Alexandria and Syene by the result to determine the circumference of the Earth. Remarkably, Eratosthenes determined the circumference to be 25,000 miles, just 99 miles over the actual circumference at the equator (24,901 miles). Although Eratosthenes made a few mathematical errors in his calculations, the, canceled each other out and yielded an amazingly accurate answer that still causes scientists to marvel. A few decades later, the Greek geographer Posidonius insisted that Eratosthenes circumference was too large. He calculated the circumference on his own and obtained a figure of 18,000 miles—about 7,000 miles too short. During the Middle Ages, most scholars accepted Eratosthenes circumference, though Christopher Columbus used Posidonius measurement to convince his supporters that he could quickly reach Asia by sailing west from Europe. As we now know, this was a critical error on Columbus part. Had he used Eratosthenes figure instead, Columbus would have known he was not yet in Asia when he landed in the New World. Prime Numbers A noted polymath, Eratosthenes also made notable contributions to the field of mathematics, including the invention of an algorithm used to identify prime numbers. His method involved taking a table of whole numbers (1, 2, 3, etc.) and striking off the multiples of each prime, beginning with multiples of the number two, then multiples of the number three, etc. until only the prime numbers remained. This method became known as the sieve of Eratosthenes, as it works by filtering out the non-prime numbers in the same way that a sieve filters solids out of liquids. Death In his old age, Eratosthenes became blind and he died of self-induced starvation in either 192 or 196 BCE in Alexandria, Egypt. He lived to be about 80 to 84 years old. Legacy Eratosthenes was one of the greatest Greek polymaths, and his work influenced later innovators in fields ranging from mathematics to geography. Admirers of the Greek thinker called him Pentathlos, after the Greek athletes known for their prowess in a number of different events. A crater on the Moon was named in his honor. Sources Klein, Jacob, and Franciscus Vieta.  Greek Mathematical Thought and the Origin of Algebra. Courier Corporation, 1968.Roller, Duane W.  Ancient Geography: the Discovery of the World in Classical Greece and Rome. I.B. Tauris, 2017.Warmington, Eric Herbert.  Greek Geography. AMS Press, 1973.

Medical Ethics an Inclusice History - 2719 Words

Medical Ethics: An Inclusive History As long as there has been some form of medical treatment in the world, there has been someone who has voiced their ethical viewpoints on the treatment of patients. It is difficult to trace back the very first ethical thinking in medicine, but Islamic and Muslim traditions have left their footprints in Medical and Bioethics since before the medieval and early modern period. The first piece of literature ever dedicated to the field of medical ethics was written in the 9th Century by Ishaq bin Ali Rahawi and was titled Adab al-Tabib or Conduct of a Physician. Ali Rahawi reffered to physicians as guardians of the soul and body. One of the features in medieval Muslim medicine that separated their†¦show more content†¦Kevorkian made headlines internationally when he undertook a well publicized assisted-suicide campaign between 1990 and 1998 that reportedly ended the lives of approximately one hundred thirty people. Some of those whose deaths Kevorkian facilitated were termi nally ill and diagnosed as having less than six months to live, but most were disabled or chronically ill. He would hook his patients up to a â€Å"Suicide-Machine† that would result in a painless death. Though controversial, his contributions to the ethical issues of Physician Assisted Suicide and Euthanasia are unparalleled. This issue brought light to people’s free will in choosing death over life and was a key influence in hospitals allowing patients to fill out advanced directives. His work raised the question of whether euthanasia should be legalized and if it is ethical. The media interest brought on by this case illuminated issues such as â€Å"Dying with Dignity† and the â€Å"Right to Die Movement.† Though his work faced immense opposition, he is still regarded as one of the most influential figures in modern healthcare ethics (Betzold, 1993). Yet another major figure in the field of medical ethics was Hippocrates who is believed to have written the Hippocratic Oath. The Hippocratic oath is a sworn statement that doctors make even today to practice medicine in an ethical manner. It requires a

Designing and Managing the Supply Chain, Chapter 1 Questions free essay sample

These subassemblies are assembled during final assembly and then distributed to dealership for the consumer market. b. What are the different firms involved in the supply chain? The following are a selection of firms involved in the supply chain: Suppliers, Manufactures, Transportation companies, Warehouses and distributions centers, sub-contractors, dealerships, and customers. c. What are the objectives of these firms? The simple objective of these firms is to maximize market share and make a profit. Every challenge to operate the supply chain supports these two primary goals. d. Provide examples of conflicting objectives in this supply chain? The supplying industries would like the automobile manufacture to commit themselves to purchasing large quantities with stable volumes with flexible (long-lead) dates. On the manufacture’s side, they need to be flexible to their customers’ need and the change in demands. So what we have is a direct conflict of interest between the suppliers’ and manufactures’ desire for flexibility. We will write a custom essay sample on Designing and Managing the Supply Chain, Chapter 1 Questions or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page The ability to optimally match supply and demand is just as much an art and it is a science. Other conflicts arise with transportation of smaller batches versus larger batches of supplies. Usually the smaller and faster a batch of supply is required, the cost of transportation increase; another conflicting objective. e. What are the risks that rare or unexpected events pose to this supply chain? An unexpected risk such as a natural disaster can bring the supply chain to a stand still. However, such events can almost never be managed. There are some challenges such as matching supply and demand risks, lead times, forecasts, transportation times and costs, which can be â€Å"managed† or operational risk management used to minimize risks. 2. Consider a consumer mortgage offered by a bank. f. What are the components of the supply chain for a mortgage? There are several components of the supply chain for a consumer mortgage offered by a bank. First, there are marketing companies that solicit to prospective customers. Secondly, the bank needs to be able to evaluate potential customers by using credit-reporting companies. Thirdly, usually a third party bank that extends the mortgage loans. Lastly, the bank requires mortgage brokers that distribute the loans. g. Is there more than one firm involved in the supply chain? What are the objectives of the firm or firms? Marketing companies try to increase the responses from prospective homebuyers to maximize their returns. The banks try to find customers that are a relatively low risk, on-time payments, and low average maturity date; i. e. , maximize profits. The mortgage broker is all about maximizing his commission of the sell of the property. . What are the similarities between product and service supply chains, what are the differences? Both product and service supply chains provide a need. The difference is the type of service, instead of the physical product†¦ faster, better, cheaper all apply. Some of the differences between the two types of supply chains are as follows: * With the product supply chain there is both the flow of physical and infor mational products. However, in the service supply chain, the product is mostly information. Unlike the service supply chain, inventory and transportation of goods are a major costs of product supply chains. * Since service supply chains usually don’t carry inventory, coordinating capacity with demand is usually more important. * The cost of information is more often higher than in a product supply chain. Consider the cost of a credit report or hiring a consultant. 6. Consider the supply chain for canned peaches sold by a major food-processing company. What are the sources of uncertainty in this supply chain? Some of the sources of uncertainty are as follows: The first factor to consider is the peach crop and the factors that effect it†¦ weather, disease, and disasters. * Number if migrant workers available to harvest the crop†¦ spoilage. * Lead times from field to processing plant†¦ spoilage. * Processing time, storage, and transportation times and costs. * Dem and is not know beforehand. CASE: Meditech Surgical 1. What are Meditech’s problems in introducing new products? In manufacturing ALL products? Meditech has two major issues with introducing new products. * It has poor service levels for new products The inventory levels are higher than necessary for all of its products 2. What is diving these problems, both systematically and organizationally? There are seven major areas in which Meditech is driving these problems: * In the planning system, there are too many built-in delays and monthly buckets. This leads to inefficacies, unneeded delays, and high inventory levels. * There is no tracking of forecasting errors. * Product demand is poorly studied. * The Info Systems used to record and monitor amp; inventory are not integrated and inadequately designed. Because Meditech does not normally see the end-customer, it has to overcome failures of communications with them†¦ hording/panic orders is one example of this failure to c ommunicate with end-customers. * The poor planning system is use magnifies variations in demand. * Panic ordering. 3. Why is the customer service manager the first person to recognize the major issues? He was the person who directly received customer complaints. In his position he was able to determine the scope of the problems. Other managers were not in positions to be aware of customer satisfaction. 4. How would you fix these problems? There are several ways to fix the problems Meditech is facing. The first and most important is improving communications with customers†¦ Five â€Å"Y†Ã¢â‚¬â„¢s. Another way to improve their SCM is to develop better demand forecasting systems and accountability for their forecasts. Furthermore, Meditech needs to integrate, implement, and improve their information systems. They could easily eliminate bulk inventory by putting assembly within the pull system; i. e. , get rid of the â€Å"push-pull† system. Lastly, they could implement a planning system to decrease planning delays (or just use M. S. Project) and reduce system time buckets.

Research Methods for Emerging and Selected Topics - myassignmenthelp

Question: Discuss about theResearch Methods for Emerging and Selected Topics. Answer: Introduction In order to deal with the crisis of the energy, it is important to increase the popularity of the electric vehicles. These vehicles are mainly dependent on the charging from the electrical sources that are able to power up the engine. Lukic and Pantic (2013), have mentioned about the fact that the electrical vehicles lost huge amount of time in the process of charging that is an essential part of the overall process. Hence, it is important to note that in most of the occasions, the process of wireless charging needs to be implemented in order to save the time that is required by the electronic vehicles in the overall time that is needed in the process of charging. According to Musavi et al. (2012), the wireless process of charging can also help to save the time that is needed in the charging of the engine. The potential that exists in the process of electrification of the cars can help to attract several types of research in the respective fields in the given case. The main purpose o f the research of the research is to improve upon the commercial applicability of the wireless form of charging that can help in the process of dealing with the issues related to the energy crisis. The research paper of Miller et al. (2014), have mentioned about the application of Inductive Power Transfer (IPT) that has been used successfully in many electronic vehicle systems. This is one of the most important matters related to the powering of the electric vehicles. The process of wireless charging has been adopted by many of the top automobile brands including Mercedes Benz and BMW. The basic principle of wireless charging is in this case based on most of the inductive level of charging. Capacitive power transfer is also one of the important technological improvements of wireless charging. The capacitive process of charging that is used in the process of isolation is needed to deal with minimizing the cost of wireless charging. It is also believed to be one of the convenient modes of portable electronic devices, which can be used to power up the devices. Wireless charging can also be the advancement in the process of autonomous charging concept that is used by most of the luxurious automobile brands (Bi et al. 2015). It is also based that in most cases, wireless charging is related to the bidirectional form of charging, that is related to high effective forms of charging system, which is believed to be one of the economic ways. Onar et al. (2013), have mentioned about the importance of efficiency due to the fact that internal engines are able to have longer life span. With the help of the specially designed coiled system within the internal engine, it is possible to deal with most of the cases related to the internal engines. It is also important to mention that wireless charging electric vehicles produce much fewer air pollutants compared to that of traditional engines. Hence, with the help of this mechanism, it is possible to reduce the effect of environmental degradation (Zhang et al. 2016). In Spite of the advantages of electric cars, they have limited range due to the fact that it is not possible to provide charge in all places. Therefore, electric cars cannot be relied upon for long distance journey. However, with the introduction of wireless charging system, it is possible to neutralize this limitation. This makes the electric car more users friendly and practically suitable for all types of situation. A hybrid system that is used in the electric vehicles also enables them to get the engine power from any source of electricity. Developers of the wireless charging automobile vehicles have enabled them to deal with the challenges related to the developing system. The wireless charging is based upon the principle of electromagnetism, which enables them to deal with the challenges related to the use of petroleum product. The type of the battery that is used in the car is also dependent upon the type of electronic charging system that is being implemented (Li and Mi 2015). Another major advantage of the wireless charging technology is due to the fact that it is possible to integrate the shape of the device within tiny wireless charging receiver. Hence, it is possible to improve upon the overall sizing of the battery and car engine (Rajashekara 2013). It is also possible for multiple numbers of devices to be charged simultaneously, which is believed to be one of the effective ways of saving time. There are numerous multiple devices is charging stations that have become popular in the recent years. As there is a minimum amount of cables required in the overall process of charging, it is possible to save vital space within the charging station. On the other hand, the major disadvantages that are related to the use of wireless charging system are due to the fact that it is related to various health concerns. The electromagnetic radiation through which the wireless charging system is operated can cause major health issues if they are being exposed to human for longer duration. It can also cause critical diseases like tumour or cancer (Xie et al. 2013). In spite of the fact that wireless charging system is believed to be one of the economic ways of powering up automobile vehicles, the initial cost of setting up the infrastructure is generally very high. In spite of its popularity, due to the high-cost offsetting of the infrastructure, it is not possible to commercially implement the wireless charging system. It is important for the future research has to focus on the ways to improve the efficiency of the cost that is involved in setting up the infrastructure for the wireless charging system. It is also important to ensure that minimum amount of harm is being caused due to the electromagnetic radiation that is an important component of wireless charging system. Reference Bi, S., Ho, C.K. and Zhang, R., 2015. Wireless powered communication: Opportunities and challenges. IEEE Communications Magazine, 53(4), pp.117-125. Li, S. and Mi, C.C., 2015. Wireless power transfer for electric vehicle applications. IEEE journal of emerging and selected topics in power electronics, 3(1), pp.4-17. Lukic, S. and Pantic, Z., 2013. Cutting the cord: Static and dynamic inductive wireless charging of electric vehicles. IEEE Electrification Magazine, 1(1), pp.57-64. Miller, J.M., Onar, O.C., White, C., Campbell, S., Coomer, C., Seiber, L., Sepe, R. and Steyerl, A., 2014. Demonstrating dynamic wireless charging of an electric vehicle: The benefit of electrochemical capacitor smoothing. IEEE Power Electronics Magazine, 1(1), pp.12-24. Musavi, F., Edington, M. and Eberle, W., 2012, September. Wireless power transfer: A survey of EV battery charging technologies. In Energy Conversion Congress and Exposition (ECCE), 2012 IEEE (pp. 1804-1810). IEEE. Onar, O.C., Miller, J.M., Campbell, S.L., Coomer, C., White, C.P. and Seiber, L.E., 2013, March. A novel wireless power transfer for in-motion EV/PHEV charging. In Applied Power Electronics Conference and Exposition (APEC), 2013 Twenty-Eighth Annual IEEE (pp. 3073-3080). IEEE. Rajashekara, K., 2013. Present status and future trends in electric vehicle propulsion technologies. IEEE Journal of Emerging and Selected Topics in Power Electronics, 1(1), pp.3-10. Xie, L., Shi, Y., Hou, Y.T. and Lou, A., 2013. Wireless power transfer and applications to sensor networks. IEEE Wireless Communications, 20(4), pp.140-145. Zhang, Y., Chen, K., He, F., Zhao, Z., Lu, T. and Yuan, L., 2016. Closed-form oriented modeling and analysis of wireless power transfer system with constant-voltage source and load. IEEE Transactions on Power Electronics, 31(5), pp.3472-3481.