Dmitri Mendeleev essays

Dmitri Mendeleev essays Dmitri Mendeleev was the youngest of at least 14 children in his family. They lived in Tobolosk, Siberia. His father, Ivan, was the director of a gym and his mother, Marya, came from a family that introduced glass and paper making to Siberia. Mendeleevs father died while he was still young, and Marya had to work. Luckily, her family was able to get her a managers position at the Korniliev glass factory at Aremziansk. Dmitri was educated at his fathers gym in Tobolosk, where he showed a high interest in physics and mathematics. Also, he was taught many things about glass and glass blowing from the family factory. His brother-in-law, Bessargin, taught Mendeleev about current science topics. When Mendeleev was 14, his mother had already noticed his gifted abilities in Science and wanted to help him get a good education. All that changed when the family factory burnt down. Within a few months, Dimitri's mother and sister had died from tuberculosis. Mendeleevs most significant accomplishments were his discovery of periodic law and the making of the periodic table. He had a great interest in the elements, which up to his time were distinguished by only one basic property, which had been proposed by John Dalton in 1805, that each element has a characteristic atomic weight. Mendeleev wrote the elements out on cards, atoms had their atomic weights and were set out in columns in order of atomic weight. He was unclear what to do with hydrogen, the lightest, and left it out. Scientists had identified over 60 elements by Mendeleev's time. (Today over 110 elements are known.) In Mendeleev's day the atom was considered the most basic particle of matter. The building blocks of atoms (electrons, protons, and neutrons) were discovered only later. What Mendeleev and chemists of his time could determine, however, was the atomic weight of each element: how ...

A Study of Succession in the Dragonfly Pond Essays

A Study of Succession in the Dragonfly Pond Essays A Study of Succession in the Dragonfly Pond Essay A Study of Succession in the Dragonfly Pond Essay Succession The combination of processes, which produce a gradual change in the structure and species composition at a particular site. Dragonfly Pond: The pond was created in 1986 by Anglian Water to provide a habitat for dragonflies. It is in a horseshoe shape and is situated next to Grafham water in Bedfordshire. Dragonfly Pond: Can Signs of Succession be Seen Around the Pond? Hypotheses: 1) The further one goes around the pond away from the open water, the depth will gradually reduce. This is because as you go along the transect more succession will have taken place, therefore the pond will be more developed containing more plants and a higher soil level due to it containing more decayed matter from each community decaying as it is succeeded until the climax community is reached and more sediment will be able to build up in the roots of the new plants. 2) There will be more vegetation as one goes further along the transect. There will be a bigger hydrosere because more succession will have taken place and therefore the conditions will favour a greater range of plants to be supported. 3) The number of submergents will decrease slowly around the pond. The amount of submerged plants will decrease as the water level falls because these are usually found as deep-water colonisers and pioneer species whos decay year after year, gradually reduces the water depth allowing more plants to succeed them. 4) The number of emergent plants will increase slowly around the pond until marshland takes over. This is because as the water shallows the emergent vegetation can now break the surface and take over from the submergents. However as more and more silt is trapped in the rooted emergents and as they decay the water level decreases still further and marshland plants should be able to establish themselves. Planning To collect data from the pond we decided to have 15 data collection points along a 50m transect at 3.5m intervals. I chose a grided quadrat held at arms length facing away from the bank to collect values for percentage cover of emergent, submergent and marsh plant cover at each point. The quadrat had 100 squares and thus I was able to count how many full squares there were to record percentage readings. The depth I measured at arms length with a depth pole to the nearest cm. By taking points on a transect I was using a systematic sampling technique. I spent 1hour collecting the data. Risk Assessment When collecting data I was careful to step on firm ground and tried to keep off the edge of the bank and a dry sunny day was chosen to reduce the risk of falling into the pond. Accuracy and Reliability of the Data The depth was taken to the nearest cm of the depth pole and I held it at arms length from the bank for each measurement. The quadrat was held at waist height and at arms length for each measurement, however it was sometimes difficult to accurately count the number of full squares covered by a plant type. Proving Hypotheses: To prove hypothesis 3 I used spearmans rank correlation coefficient to show that there was a direct link between the depth of water decreasing and the number of emergent plants. The correlation coefficient can then be put in to a graph to give a significance level of similarity between the two factors. (see working) The significance level came out to 1% so there is definitely a strong correlation. The similarity can also be seen clearly on graph 3 where the submergents decrease rapidly after an anomalous bare ground reading at the first transect. This anomaly may have been caused by the submergent plants at this point being covered by soil falling in from the bank leaving very few plants to be seen here. A further anomaly can be seen on the percentage of total plant cover (graph 5). There appears to be very few plants at point 8, this in fact was a mud strip used as a walkway to the centre of the pond and thus plants had not taken root here. I also used spearmans rank to prove hypothesis 1 to show a direct link between depth of water decreasing with distance around the pond. The significance level came out at 1% so there is also a strong correlation. The general trend can also be seen on graph 1 where the trend line clearly shows a gradual decrease in depth with distance along the transect. This indeed should be the case because the further around the transect one goes more succession will have taken place. The pioneer species will have been succeeded by more advanced plant through autogenic succession. The submergent plants, grow up and decay year after year, gradually decreasing the depth and changing the substrate until rooted emergent vegetation takes over. The rooted vegetation traps sediment, which decreases the depth even more. Hypothesis 4 can be proved by looking at graph 4. From the trend line the number of emergent plants increases slowly with distance around the pond. This is because the emergent vegetation of the common club rush and pampus grass have established themselves more as the depth decreases. The marshland sere however has not yet fully developed and therefore didnt impact much on the graph. This should be the case as the water depth decreases further still by the decay of emergent plants but the minimum depth of 20 cm is still probably too high for marshland scrubs. Hypothesis 2 predicted more vegetation as one goes around the pond, this cant be seen from the graph of total percentage plant cover (graph 5). The graph shows very high levels of percentage plant cover along the transect and no distinct increase or change. This doesnt support my hypothesis but its not to say the hypothesis is necessarily wrong. The hydrosere has developed from the single type of submergent plant . To a number of emergent plants and even a few marsh plants. To try to prove this I should have counted the number of different species at each point on the transect. So in summary: Depth and submergent plants decreases along the transect. Emergent plants increase along the transect. Total percentage cover of plants is high throughout. Evaluation: I thought the investigation was very successful as I was able to prove all but one of my hypotheses and thus I was able to build up a clear picture of the changing seres. The main aim of the investigation was achieved in that of showing a presents of succession at the pond. The only sere not yet developed was that of marshland but in years to come no doubt it will be clearly visible as the climax community is reached in the pond. The only extension to my project could be that of collecting more data, such as that of the total number of different plant species at each point and this would have enabled me to prove Hypothesis 2

Matewan and Harlan County USA

Matewan and Harlan County USA Matewan ‘Matewan’ is an American drama film by John Sayles that narrates a story of the events of struggle to unionize the West Virginia coal-minors in 1920s. According to Sayles, the Stone Mountain Coal company was the only dominant company in the Western Virginia in the 1920s. Sayles (1987) notes that the Stone Mountain was the only mining company in the region at the time an advantage it used to monopolize every mining business opportunity in the region.Advertising We will write a custom critical writing sample on Matewan and Harlan County USA specifically for you for only $16.05 $11/page Learn More This monopoly forced miners into bondage contract with the company since they had no alternative with regard to employment. In addition, since workers had no alternative place to seek employment, it became easy for the Coal Company to oppress workers by offering low pay and making them work under poor conditions. To make matters worse, employees d id not even know their employers who did not even bother to show up in the company. Instead, company representatives took of every responsibility of supervising their work. Nonetheless, Sayles reveals that the representatives remained excessively oppressive as they used intimidation to force workers to deliver what they wanted (Sayles, 1987). Sayles noted that apart from threats from company representatives, miners took home petty remuneration with no complaints. In addition, the Coal Company restricted workers freedom as consumers in, which miners had to buy everything from the company from food to clothes. Equally, the management team forced workers to buy tools from the company to ensure that all the money they obtained circulated back to the company. Further, the Coal Company in most cases charged workers higher prices for their purchases than normal market charges (Sayles, 1987). Therefore, growing intolerant of the hash and unjust rules, the miners decided to strike against th e company. Strike motivation aimed at forcing the Coal Company to offer better working conditions. However, in order to drive their agenda, the miners found it prudent to unionize in order to form a stronger presence and opposition against the Coal Company. This is because the miners felt that it was only through union that they could mount a strong and formidable opposition to force the company to recognize their rights (Sayles, 1987). Harlan County USA ‘The film Harlan County USA’ dramatizes a coal miner’s strike at the Brookside mine in Harlan County, Kentucky. According to the film director, the Brookside mine belongs to a private owner run under the Eastover Mining Company.Advertising Looking for critical writing on political sciences? Let's see if we can help you! Get your first paper with 15% OFF Learn More Unlike in Matewan, where workers found motivation to form a union to enable them push their agenda, Harlan County’s work ers already belonged to a union called the Southern Labor Union. The union drew membership from the entire Eastern Kentucky to propagate the plight of the workers before company authorities (Kopple, 1976). The documentary reveals that workers of Brookside mining company felt unhappy with the working condition at the mining site as observed in Matewan. This is because, despite doing a lot of hard work, they received extremely low salaries compared to what their unionized counterparts got. Kopple (1976) reveals that these workers received a salary ranging from $17 to $32 per day, which was way below the $45 that their counterparts got. In addition, the company had not assured them of safety as several injuries used to occur, estimated at three times above the national average. Therefore, they opted to strike demanding the right to form their own safety committee elected by the union members. They also wanted their salary increased to $45 per day as received among their counterparts. I n addition, the miners wanted the company to pay the standard UMW rate of 75 cents for every ton, remitted directly to their medical and retirement benefits (Kopple, 1976). The two films also share many similarities with regard to worker motivation and sustenance of morale in the mining industry depicted in US history (Blanchflower and Freeman, 2001). As witnessed in both films, workers unionize in order to form a formidable force to push for the recognition of workers’ rights. However, the two films differ in the sense that whereas the Matewan workers struggle to unionize, Eastover readily allowed workers’ union. Despite unionized approach, workers in Eastover still fight for their rights seemingly violated by the company in breach of union terms. References Blanchflower, D. D., Freeman, R. B. (2001). Unionism in the United States and other advanced OECD countries, Retrieved from dartmouth.edu/~blnchflr/papers/indrel.pdfAdvertising We will write a custom crit ical writing sample on Matewan and Harlan County USA specifically for you for only $16.05 $11/page Learn More Kopple, B. (Executive Producer). (1976). Harlan County USA (YouTube). Bigboogertz. Retrieved from https://www.youtube.com/watch?v=iCiVMngILEI Sayles, J. (Executive Producer). (1987). Matewan-The Union (YouTube). DukatSG1. Web.

Constantine at the Battle of Milvian Bridge

Constantine at the Battle of Milvian Bridge The Battle of Milvian Bridge was part of the Wars of Constantine. Date Constantine defeated Maxentius on October 28, 312. Armies Commanders Constantine Emperor Constantine Iapproximately 100,000 men Maxentius Emperor Maxentiusapproximately 75,000-120,000 men Battle Summary In the power struggle that began following the collapse of the Tetrarchy around 309, Constantine consolidated his position in Britain, Gaul, the Germanic provinces, and Spain. Believing himself to be the rightful emperor of the Western Roman Empire, he assembled his army and prepared for an invasion of Italy in 312. To the south, Maxentius, who occupied Rome, sought to advance his own claim to the title. To support his efforts, he was able to draw upon the resources of Italy, Corsica, Sardinia, Sicily, and the African provinces. Advancing south, Constantine conquered northern Italy after crushing Maxentian armies at Turin and Verona. Showing compassion to the citizens of the region, they soon began to support his cause and his army swelled to near 100,000 (90,000 infantry, 8,000 cavalry). As he neared Rome, it was expected that Maxentius would stay within the city walls and force him to lay siege. This strategy had worked in the past for Maxentius when he faced invasion from the forces of Severus (307) and Galerius (308). In fact, siege preparations had already been made, with large amounts of food already brought into the city. Instead, Maxentius opted to give battle and advanced his army to the Tiber River near the Milvian Bridge outside of Rome. This decision is largely believed to have been based on favorable omens and the fact that the battle would occur on the anniversary of his ascension to the throne. On October 27, the night before the battle, Constantine claimed to have had a vision which instructed him fight under the protection of the Christian God. In this vision a cross appeared in the sky and he heard in Latin, in this sign, you will conquer. The author Lactantius states that following the visions instructions, Constantine ordered his men to paint the Christians symbol (either a Latin cross or the Labarum) upon their shields. Advancing over the Milvian Bridge, Maxentius ordered it destroyed so that it could not be used by the enemy. He then ordered a pontoon bridge constructed for his own armys use. On October 28, Constantines forces arrived on the battlefield. Attacking, his troops slowly pushed back Maxentius men until their backs were at the river. Seeing that the day was lost, Maxentius decided to retreat and renew the battle closer to Rome. As his army withdrew, it clogged the pontoon bridge, its only avenue of retreat, ultimately causing it to collapse. Those trapped on the north bank were either captured or slaughtered by Constantines men. With Maxentius army split and decimated, the battle came to a close. Maxentius body was found in the river, where he had drowned in an attempt to swim across. Aftermath While casualties for the Battle of the Milvian Bridge are not known, it is believed that Maxentius army suffered badly. With his rival dead, Constantine was free to consolidate his hold over the Western Roman Empire. He expanded his reign to include the entire Roman Empire after defeating Licinius during the civil war of 324. Constantines vision prior to the battle is believed to have inspired his ultimate conversion to Christianity. Selected Sources Constantine the GreatLactantius Account of the BattleEusebius Life of Constantine

Week 2 group assignment Essay Example | Topics and Well Written Essays - 500 words

Week 2 group assignment - Essay Example This might be because they knew that there current warehouse would not process any problem for the Medical Instrument Inc. hardware, thus restraining from entertaining any arbitration clause. Another reason might be that, in spite of arbitration being of low cost, CP perhaps didn’t see the need or any problem which may call upon such procedure. Nevertheless, the very next lease contained the formerly absent arbitration clause. (Cross, 2011) This step could mean that Commercial Properties either knew about the defaults of their new warehouse or had projected that the coming years might be less difficult with MII if they have an arbitration clause in an agreement. As the main aim of arbitration is to ensure that the opposing parties can settle any dispute without rushing to a trial and can overcome a conflict with the presence of a third party, which will also be able to make a neutral decision based on the evidences and witnesses. Hence, the decision to include the clause in new lease seemed viable. Travelling to California for the arbitration procedure will be essential for MII because it’s mandatory that any tenant who needs to have an access to the attribution clause will have to go through the CP’s home state of California. (Cross, 2011) On the surface there is no reason to rule the arbitration clause invalid, as the MII signed the lease papers without any objection. Moreover, MII also informed the CP about the leakage as soon as the problem surfaced. On the other hand, this clause can also be declared invalid if the CP claimed it to be too burdensome (Cross, 2011). Q3. The two cases concerning the arbitration method are Brower vs. Gateway Inc. and Green tea Financial Corporation vs. Randolph. Both the two cases discussed the dispute and how arbitration clause worked out form them. However, both the cases did not held much relevancy for the CP vs. MII case as the former cases already had an agreement on arbitration clause from the start of the

Nuclear Power Assignment Example | Topics and Well Written Essays - 500 words - 1

Nuclear Power - Assignment Example to Cravens and Rhodes (2008), developing nuclear power will lead to low cost of power because uranium, which is the key raw material of nuclear energy does not commonly experience frequent price fluctuations as compared to other fossil fuels. Secondly, nuclear power does not witness frequent interruptions as compared to hydroelectric power and Mahaffey (2011), further stated that it could run for more than 700 days uninterrupted. Thirdly, developing nuclear energy leads to less environmental pollution because they have a minimal emission of greenhouse gases. According to Cravens and Rhodes (2008), the main disadvantages of developing nuclear power stems from safety concerns that are attributed to the raw materials used in the development process and even the waste or by products that originate from nuclear power plants. For example Cravens and Rhodes (2008), stated that uranium that is used in developing nuclear energy is unstable and therefore its mining , transportation, and even transformation is a dangerous process of which in case of an accident the consequences can be grave. Secondly, the waste products that result from nuclear energy development are usually radioactive and hence if they find their way to the surrounding environment they can pose serious dangers to the health of the people, animals, and plants. Thirdly, in case of an accident at a nuclear power plant the consequences are usually grave and they can last for many years. According to Mahaffey (2011), the 1986 Chernobyl nuclear disaster is one of the worst nuclear disasters in the World’s history, which was caused by a fire explosion at the nuclear power plant that lead to deaths, injuries, and the emissions of large quantities of radioactive particles that spread wide across the region. The disaster is still fresh in the minds of many since its effects are still evident up to date because of various cancer cases and deformities that are attributed to the 20th century accident. Mahaffey

Research Paper on a Terrorist Group Example | Topics and Well Written Essays - 1750 words

On a Terrorist Group - Research Paper Example The â€Å"Al Qaeda† was formed in Afghanistan in 1989 to fight the members of the Soviet Union in that country. During that time, the Soviet Union wanted to suppress a budding Islamic Revolution. Thus, the founders of Al Qaeda wished to counter this oppression under the common banner of Islam. A huge number of Arab Afghans travelled from all parts of the Arab world to participate in this â€Å"jihad† and enrolled at the recruitment camp of the organization at Peshawar, situated at the border of Pakistan and Afghanistan. Osama bin Laden and Dr. Ayman al-Zawahiri arrived at Peshawar and took over the leadership of the group. During the beginning the organization functioned as a hierarchical structure to facilitate its participation in the war against the Soviets. This arrangement helped the group to send military troops and war aids to Afghanistan and gradually prepared the organization to launch a concerted attack on the countries of the Western world. Thus, during the e arly years of its formation, the Al Qaeda was a highly structured and systematically arranged organization. After the Soviet troops were defeated in Afghanistan, the group changed its structure into a network organization. (Mishal, Rosenthal, 2005, p 3) The Al Qaeda can be classified as an international political terrorist organization. In the opinion of Mishal and Rosenthal (2005), the organization followed a hierarchical order in the beginning and later changed into a network organization. After the attack on Afghanistan in 2001, it assumed the form of a Dune organization. During the time, when the Al Qaeda was engaged in a war with the Soviets in Afghanistan, the group was a hierarchical organization. It was divided into small units which were arranged like pyramids under the group’s common leadership. After its transformation into a network-based organization, the structures within the group were redefined. Al Qaeda became more of a transnational organization which was willing to direct its activities towards multiple causes. During the period 1998 – September 2001, the terrorist group operated as a network organization. (Mishal, Rosenthal, 2005, p 2) Objectives The Al Qaeda was initially formed to counter the Sovi et Union’s attack on the growing Islamic revolution in Afghanistan. After the defeat of the Soviet troops, the group became a transnational organization which was engaged in pursuing a number of causes as its objectives. In February 1998, Osama bin Laden brought together a group of state-level Muslim leaders and organizations to form the â€Å"World Islamic Front for Jihad against the Jews and Crusaders (IIF)†. The IIF formulated its objectives in accordance with the World Islamic Front Statement of 1998: to free the al-Aqsa mosque and the Holy Mosque of Mecca from the hold of America and it allied nations, it was the duty of every Muslim to extricate civil and military citizens of USA and its allies. They were free to carry out their mission in any country which they