Sir Richard Hawkins Essay Example for Free

Sir Richard Hawkins Essay Sir Richard Hawkins was an explorer, soldier and privateer. He followed in his father footsteps and became a well-respected mariner. He explored his whole live and never stopped looking for adventure out on the open see. We began with his live on land, then his maritime days and last end up at why he was such an important explorer and sea farer. Sir Richard Hawkins life began in Plymouth around 1562 to Katherine and John Hawkins. His dad was a famous Elizabethan explorer. Richard Hawkins never went to school. He grew up in the company of many mariners, including his father, William Hawkins, his uncle and Sir Walter Raleigh, learning about the sea and its trade. When he was 22 he went on his first voyages with his uncle, William, to Brazil. This was the start of Richards Hawkins expeditions and life on see. Richard Hawkins married Judith (Dame) Hele and had 6 children. The first, born in Deptford in 1592 was Judith, and then came Margret in 1603, John in1604, Richard, Johan 1607 and Mary. He bought the house and manor of Poole and Slapton located between Dartmouth and Start Point. This is where you spent the years of 1603 to 1605 writing a book called â€Å"Observations on His Voyage into the South Seas, AD 1593†. Richard at the age of 58 he continued his need for adventure by leading and expedition to the Mediterranean against the Barbary or North African pirates. Richard died on April 17, 1622 at the age of 60 in Slapton England. Richard Hawkins had many adventures at sea and continued to for as long as he lived. While on his trip to Brazil with his uncle, he captained one ship and was second command of another. They arrived back in Plymouth in November of 1582 with a bounty of around 8000.000 crowns. His next captaining job was of the Duck which carried of 240 guns of Spain’s and forced Spain to concentrate on strengthening their colonies defense. 2 years later he was captain his own ship called the Swallow, which he led against the Spanish Armada along with lending two more of his own ships. This was a battle lead by the Spanish against the British because of the protestant rule of Elizabeth I and piracies by British ships against the Spanish trade. It is said that Richard’s ship was the most damage. In 1590 Richard sailed with his father, who commanded a fleet of 6 ships to sail along the Spanish coast plundering goods. In 1593 he obtained a ship from his father, first named Repentance by his mother but changed to Dainty by the Queen. He departed Plymouth, crossed the Atlantic and raided Valparaiso, but was captured by several ships, 1300 Spaniard against his 75 men. He surrendered after the third day after being wounded on the condition his men be set free. He was imprisoned in Peru for 3 years and then in Madrid, where he attempted to escaped but was caught. He was ransomed for  £3,000 in 1602 which his step mother begrudgingly paid. When he return home he was knighted by King James the I, became mayor of Plymouth and its MP in the parliament. Sir Richard Hawkins was a very important man, a solider, navigator, shipbuilder, commander, father, son and employee. He is best known for his voyage to South Africa. Richard Hawkins also discovers the Falkland Islands which he mapped and named Hawkins Maidenland. Hawkins wrote the memories of his first sea trip under the title â€Å"Voiage into the South Sea†, which became the most famous Elizabethan adventure, re-published by the Hakluyt Society and reworked in Charles Kingsleys Westward Ho! He also used three of his own ships in the Armada in which he fought and risked his life and property to help the British won. He also was in England’s politics as a parliament member. He bombarded the Spanish fleets by stealing gold and treasures, enabling England to compete with Spain and supporting his country. Also, when he was captured by Spain he sacrificed himself for his crew. Without Richard sacrifice his crew could have been killed. From the beginning with Richards’s father also being an important mariner, it makes sense that Richard should become a mariner that surpasses his father. From the start of his first time to sea at 22 he never stopped seeking exploration and adventure. Without his contributes to exploration, parliament, the Armada, his novels, and his sacrifices to his men, country and family, the world would not be the same.

High School Graduation Essay Example for Free

High School Graduation Essay Throughout life people go through so many hardships. Whether it be good or bad there is always something that comes out of the situation. One of the most exciting but yet scariest events would be graduation. So it was the day before graduation and we were having our graduation practice. Standing outside in the line alphabetical order me and classmates talked and waited for practice to start. The sun was beating down, the smell of fresh cut grass filled out our nose. We were all just ready to get it over with. Sitting talking with my classmates discussing our future plans. Debating whether or not we will miss high school, but knowing we will definitely miss each other. So finally it came to practice walking across the stage, so the assistant principle called my name and shook my hand and handed me my mini diploma. Then it finally hit me like a speeding express train, I was about to graduate. May 18th 2012, finally it was here the day of my commencement. I can almost remember that day like it was yesterday, I awoke like on any other school day. That day was crazy, I was running errands and preparing for my graduation and after party. So the time had come for me to put on my blue and gold cap and gown with my gold cords which I had worked so hard for. I had so much sense of pride at the moment all I needed was my diploma in my hand. So the final moment had come and it was time to walk the field. The music stared and we proceeded to walk down the field to our seats. Glancing out at the packed stands I could see my family and friends. While waiting for my name to be called, I reminisced on all the good times I’ve had in high school and all the friendships I’ve made. Finally my row was directed to get up and proceed to the stage and my heart was racing. Thinking it was finally over, no more high school. I hear my name called and I hear all of my family and friends screaming and clapping for me and it made everything I had done to achieve the diploma my principle handed me after shaking my hand. As I was walking back to my seat with my diploma I was envisioning that I had just closed one chapter to my life and I was excited to embark or my next journey. Graduation is an exciting time in a person’s life, especially a high school graduation. When I think of family and friends gathering together to celebrate a joyous occasion, I feel I accomplished my strongest goal. It never occurred to me that graduation would be the end of my youth and the start of adulthood. Graduating from high school was an influential event that gave me a new outlook on life.

Carbon Nanotubes for Nano-particle Field Extraction Thruster

Carbon Nanotubes for Nano-particle Field Extraction Thruster Using carbon nanotubes as propellant for nano-particle field extraction thrusters Stefan Seuleanu Introduction Carbon nanotubes have been a research focus for more than two decades due to their unique physical properties and have been used so far in a variety of appli- cations. A possible application of carbon nanotubes is their use as propellant for an electric propulsion prototype, the nano-particle field extraction thruster (nanoFET). The nanoFET accelerates and ejects conductive particles in order to provide thrust1 . Its main advantage over other electric propulsion systems, such as ion or arcjet thrusters, is its variable specific impulse and thrust, while maintaining a high internal efficiency1 . Theoretically, the nanoFET propulsion system can be used for a large range of orbital and deep space exploration sit- uations, offering the possibility of decoupling the spacecraft design from the propulsion system4 . However, to date, nanoFETs have not been researched ex- tensively and much of the experimental work is still to be expected. This paper will investigate the possibility of using carbon nanotubes as nanoFET propel- lant by considering their relevant physical properties. By understanding how the nano-particle field extraction thruster works,this account also motivates the use of carbon nanotubes as propellant, despite their current high price. Properties and characteristics of CNTs Firstly, it is important to understand the relevant characteristics that make CNTs desirable for the nanoFET propulsion system. A carbon nanotube is a tubular/cylindrical structure that can be visualized as a wrapped sheet of graphene (one atom thick, two dimensional carbon based hexagonal lattice). Their size is typically a couple of nanometers in diameter and can span many micrometers in length. Carbon nanotubes can be single-walled (SWNTs) or multi-walled (MWNTs). These two characteristics will determine their aspect ratio (ratio between length and diameter), which is generally very high. As will be explained later on, the aspect ratio is a determinant factor that influences the nanoFET performance2,3 . The geometric structure of the nanotube determines its electrical properties. Based on the chiral vector (n,m), illustrated below, there are three main types of CNTs: zigzag, armchair and chiral. When n − m is a multiple of three, then the CNT is metallic, and semiconducting otherwise. Due to their geometry, armchair CNTs are always metallic, while the other types can be metallic only with the right choice of (n,m). Because there is no exact way to synthesize carbon nanotubes of only one geometry, as expected, generally one third of the synthesized CNTs are metallic and the rest are semiconducting 2,3 . Figure 1: CNT type depends on the chiral vector2 . Regarding the nanoFETs, the desired CNTs are the metallic type which implies the necessity for prior sorting before use. Moreover, the synthesized CNTs can contain geometrical †defects† that can be manipulated to improve the thruster’s performance3 . Due to the fact that the CNTs’ structure/geometry minimizes the collisions between conducting electrons, the resulting metallic tubes are highly conductive. Another characteristic is determined by the strong carbon bonds that allow high current to flow at low resistivity. This properties will become relevant when explaining the charging stage of the nanoFET 2,3 . The stages of a nanoFET The acceleration of a particle by a nanoFET can be divided into several stages. By assuming that the particles have been already sorted for the desired thrust, the first stage is the transportation of the particles to the charging pad. The transportation of the particles can be achieved either trough a dielectric fluid or through back pressure, hence the difference between wet nanoFETs and dry nanoFETs. For the purpose of this paper only the wet nanoFETs will be con- sidered, as the research done into dry nanoFETs has so far been minimal. The transportation liquid used for the proof-of-concept tests was silicon oil. After the particle is transported to the charging pad, the next stage is the charging process . Here the conductive particle is electrostatically charged to a desired level 5,6,8 . Figure 2: Single nanoFET emission channel cross section5 The next phase is the lift-off and extraction, which represents the application of an electric field, a potential bias between the electrode and the acceleration gates, such that the particle leaves the charging pad and moves upwards towards the liquid’s surface. At the surface, the particle must overcome the surface tension and get extracted from the liquid. After the extraction, the next stage is the acceleration of the particle trough several stacked gates. The gates have alternating insulating and conductive layers, each providing in theory an electric potential of 1000V, leading to a total of 10,000V potential that accelerates a particle to approximately 10km/s. The particle is finally ejected out of the nanoFET and thrust is produced5,6,7 . Particle behavior in nanoFETs In order to understand the behavior of the particle in a gravitational setting compared to a micro-gravitational setting, it is important to identify the forces that act on the particle at different stages in the nanoFET. The four main forces acting on a particle in a gravitational setting are the electrostatic force, the buoyant force, gravitational force and the drag force. As the cylindrical particle is transported to the charging pad, the liquid provides a horizontal inertial force. This horizontal inertial force is assumed to be low and therefore ignored in the calculations. After the nanoparticles are transported to the charging pad (electrode), they are electrostatically charged; thus contact with the electrode is necessary. If the contact is horizontal, along the length, then the charge of the particle is described by6 .: q0,cy−h = 2Ï€rlÃŽ µl El However if the contact is at either ends, so the particle is vertical on the electrode, the charge is the following6 .: l2 q0,cy−v = Ï€ ln( 2l ÃŽ µl El When the cylindrical particle is vertical on the charging pad, it gains more charge and it also requires less electric field to move upwards, as seen in the figure below6 . Figure 3: Vertically vs horizontal oriented particles a) ratio of acquired particle charge; b) ratio of required lift-off electric field6 In order to orient a particle from horizontal to vertical on the charging pad, an intense electric field focused only at one of the particle’s ends is applied. The fabrication defects that are usually present at the ends of CNTs may help to change the orientation of the particle on the electrode, requiring less electric field to create a moment that rotates the CNTs vertically. Additionally to the gravitational force, while still on the charging pad, the particle has to overcome the adhesion and electric image force in order to achieve vertical lift-off5,6 . After the particle leaves the charging pad, it has to move vertically trough the viscous liquid to the liquid surface. Therefore, the adhesion force and the electric image are no longer present; however the drag force now slows the particle’s movement. For a cylindrical particle the formula for the fluid drag used in the nanoFET calculations is given by6 : 2π µl lv D = ln( l ) + 0.193 While moving through the liquid, the particle loses charge as described by q(t) = q0 exp(− t ), where Ï„ = ÃŽ µl 5,6 . Because the particle moves fast through Ï„ ÏÆ'l the liquid, the charged loss is overall assumed to be negligible. Generally, the particle’s equation of motion is described by6 : dv (mp + K ml ) dt = q(t)El − D + Fbuoyant − W. The above equation also takes in account the added mass that is accelerated with the particle where K is a coefficient that depends on the geometry of the particle, while mp is the mass of the particle and ml is the mass of the liquid. In a laboratory gravitational environment the gravitational forces are minimal compared to the dominant drag and electrostatic forces. In a micro-gravitational environment the gravitational force and the buoyant force can be neglected5,6 . Performance and particle size For characterizing the performance of the nanoFET electric propulsion system, the space industry uses specific impulse and thrust-to-power ratio as indica- tors of performance. The specific impulse is the impulse delivered per unit of propellant consumed. In order to achieve a certain thrust, the systems that have higher specific impulse consume less propellant than the ones with lower specific impulse. For the nanoFET system the specific impulse increases as the charge-to-mass ratio of the particle increases. Thurst-to-power ratio describes the amount of thrust outputted for a specific power provided4,6 . 1 q 1 T 2 mp 1 Isp = 0 (2Vo p ) 2 ; = ( ) 2 P Vo q Moreover, the internal efficiency is given by4,6 : 1 T ÃŽ ·int = 2 g0 P Isp There are several factors that can influence the performance or the mode of operation of the nanoFET. First of all, the horizontal inertial force that the particle gains from the transportation liquid is assumed to be negligible. How- ever, this is not necessarily the case and further research needs to be conducted in order to determine its influence. Another important factor is the presence of Taylor cones and surface instability when a high electric field is present near the liquid’s surface. These cones can eject droplets and reduce the performance of the nanoFET. In order to mitigate the surface instability and the ejection of droplets, an experiment has been done to analyze how different particle shapes influence the minimum electric field needed for the extraction process. The ex- periment consists of various vacuum electric fields applied to spherical 800 µm and cylindrical 300 µm diameter and 1.5mm length aluminium particles with a total silicon oil fluid gap of 12 .7mm. As seen in the figure below, cylindrical particles can be extracted before the Taylor cones form5,6,7, . Figure 4: Taylor cone formation and particle extraction6 Furthermore, further study into the charge-to-mass ratio revealed that, for cylindrical particles, charge-to-mass ratio increases as aspect ratio increases. Therefore, at large aspect ratios, the needed extraction electric field decreases as seen in the following figure. For this reason increasing the aspect ratio of the particles increases in turn the Isp and the overall internal efficiency6 . A good candidate for further research are the CNTs due to their cylindrical Figure 5: Cylindrical particles’ vacuum extraction field simulations6 shape, high aspect ratio, good charge-to-mass ratio and fast charging. By choos- ing different CNT sizes to be used with variable gate potentials, the nanoFETs’ Isp range is theoretically very large compared to other electric propulsion sys- tem such as ion thrusters or hall thrusters. Similarly, the thrust-to-power varies greatly, which offers the flexibility of using the same propulsion system for mul- tiple missions or to perform unplanned trajectory changes at a low propellant expense. These are theoretically achieved while maintaining a high internal efficiency that is usually above 85%. For the following CNTs: nanoFET par- ticle1 16nm diameter, 3 µm length; nanoFET particle2 4nm diameter, 3 µm length; nanoFET particle3 1nm diameter, 3 µm length, the expected Isp and Thrust-to-Power ratio is illustrated4,5 . Figure 6: Thrust-to-power ratio for large specific impulse range4 Figure 7: Internal efficiency for large specific impulse range4 Discussion Apart from the large specific impulse range at high internal efficiency that pro- vides great flexibility to design a multitude of mission phases based on just one propulsion system and to accommodate for unforeseen scenarios, the nanoFETs have other important advantages over other electric propulsion system, such as potential longer operational lifetime, their geometric scalability and the fact that the system is highly integrated. The longer operational lifetime is due to the fact that the CNT particles or any other conductive particles are charged electro- statically and not ionized which eliminates the need for cathodes and eliminates charge exchange collisions that are the main lifetime reduction factors5,6 . However, there are still a multitude of challenges ahead until a fully functional prototype will be achieved. First of all, the experiments done so far that demon- strated particle transportation, charging and lift-off were conducted using mi- crometer size particles such a s Aluminum, Titanium and Indium. Although theoretically the CNTs can greatly increase the performance, no nano-size par- ticles have been experimentally used so far. Experimenting at the nanoscale might sometime reveal new problems that were not present at the micron level. Also, it is generally desirable that a quantitative experimental analysis is done in order to understand how a multitude of particles with different character- istics perform. In this way it could be determined what particle shows the most promise, although CNTs have a strong theoretical advantage mainly due to their charge-to-mass ratio. Another important factor to investigate is how the charging process changes as the size of the particle decreases to the several nanometers; the main concerns being conductivity and the contact area with the electrode. Furthermore, an investigation should also be conducted regard- ing the transportation liquid. So far, it is uncertain if a fully dielectric liquid is always desired over a slightly conductive liquid. Moreover, different liquids should be tested in order to experimentally understand how the viscosity of the liquid influences the space charge current5,6,7,8 . Finally, from an academic point of view it would be desirable that both the theoretical and experimental papers are published in a peer-reviewed journal. Conclusion Overall, the nanoFET propulsion system shows great promise due to its high specific impulse range and inherent scalability. Although it is a new concept, the most important processes such as particle transportation and charging have been already demonstrated. However, there are still a multitude of experiments that need to be conducted in order to fully understand the behavior of the system under a wide range of factors. Another interesting prospect for the nanoFET technology is their possible use , not only in the space industry, but also in medicine. The nanoFET technology can also be used to accelerate particles and inject them through cellular walls to deliver drugs. For these reasons, the nanoFET technology is an exciting and potentially rewarding research subject. References 1. Gohardani O, Elola CM, Elizetxea C. Potential and prospective imple- mentation of carbon nanotubes on next generation aircraft and space vehicles: A review of current and expected applications in aerospace sciences. July 2014. Elsevier. Progress in Aerospace Sciences 70 (2014): 42-68, ISSN 0376-0421, http://dx.doi.org/10.1016/j.paerosci.2014.05.002. 2. Loiseau A, Launois P, Petit P, Roche S, Salvetat JP. Understanding Car- bon Nanotubes. 2006. Springer. ISBN-I3-978-3-540-26922-9. 3. Dresselhaus MS, Dresselhaus G, Avouris P. Carbon Nanotubes: Synthesis, Structure, Properties, and Applications. 2001. Springer. ISBN 3-540-41086-4. 4. Liu TM, Musinski LD, et al. Nanoparticle Electric Propulsion for Space Exploration. 2007. American Institute of Aeronautics and Astronautics. Re- trieved from: http://pepl.engin.umich.edu/pdf/STAIF2 007.pdf on1stof J une2015. 5. Liu TM, Musinski LD, et al. Nanoparticle Electric Propulsion: Experi- mental Results. 2007. American Institute of Aeronautics and Astronautics. Retrieved from: http://deepblue.lib.umich.edu/bitstream/handle/2027.42/76874/AIAA-2006-4803- 539.pdf ?sequence=1 on 1st of June 2015. 6. Liu TM, Musinski LD, et al. Theoretical Aspects of Nanoparticle Electric Propulsion. 2006. American Institute of Aeronautics and Astronautics.Retrieved from: http://pepl.engin.umich.edu/pdf/AIAA-2006-4335.pdf on on 1st of June 2015. 7. Liu TM, Musinski LD, et al. Developmental Progress of the Nanopar- ticle Field Extraction Thruster. 2008.American Institute of Aeronautics and Astronautics. Retrieved from: http://www.umich.edu/ peplweb/pdf/AIAA- 2008-5096.pdf on 1st of June 2015. 8. Liu TM, Musinski L, Gilchrist B, Gallimore A. Electrostatic charging of micro- and nano-particles for use with highly energetic applications. 2008. Elsevier. Journal of Electrostatics. doi:10.1016/j.elstat.2008.11.001

Waxing A Snowboard :: essays research papers

How to wax a snowboard   Ã‚  Ã‚  Ã‚  Ã‚  There several ways to go about waxing a snowboard. Firs you have to determine what conditions you will be riding in. Then you will have to choose a wax. Say you are going to Vail and the snow condition are.... well lets just say the temp.. of the snow is about 20*. Well the thing you need to do is find a low temp. wax. The way you determine a low temp. wax from a high temp. wax is by the rating.. Low temp. waxes will be in a range from -20* to about 25*. A high temp. wax will be in a range from about 25* to 40*. There are waxes made for higher conditiond above 45* that are used in conditions that are referred to as, summer conditions. The wax that is used in summer conditions is a harder wax that will protect your board from sand, dust, and ice crystals.   Ã‚  Ã‚  Ã‚  Ã‚  If you are riding in low temp. conditions with a high temp wax your performance will not be that good. If the conditions are going to go back and forth in temp. you should wax your board with a low temp. wax or you can use a wax that can be used in all temps. WAXING INSTRUCTIONS FOR HOT WAXING   Ã‚  Ã‚  Ã‚  Ã‚  1. Select wax or waxes for correct snow temperature and condition.   Ã‚  Ã‚  Ã‚  Ã‚  2. Use in a well-ventilated area or with a respirator. (Only if you are hot waxing)   Ã‚  Ã‚  Ã‚  Ã‚  3. Heat iron below the 'smoking iron'; temperature.   Ã‚  Ã‚  Ã‚  Ã‚  4. Melt the smallest end of the wax on the iron and drip all over the snowboard.   Ã‚  Ã‚  Ã‚  Ã‚  5. Smooth out drips with iron.   Ã‚  Ã‚  Ã‚  Ã‚  6. Let wax completely dry then scrape with a plastic or metal scraper.   Ã‚  Ã‚  Ã‚  Ã‚  7. Buff wax with a buffing pad. IF YOU ARE DOING A RUB ON WAS YOU WILL NEED TO FALLOW THESE INSTRUCTIONS

white fang :: essays research papers

Part I opens as London vividly describes the "wild, the savage, frozen-hearted Northland Wild." Two men, Henry and Bill, struggle to pull the long, narrow coffin of Lord Alfred on a dog sled through the cold, desolate terrain. Dressed in fur and leather, their faces are completely covered in frozen crystals. Making the setting bleaker, the men are being pursued by a pack of hungry wolves. Down to only three cartridges for their guns, the travelers are unable to shoot at the wolves, whose behavior is becoming more brazen. Bill voices concern to Henry about an extra dog at feeding time, who appears out of nowhere and blends in with the six regular sled dogs. The next morning the men find one dog missing, lured away by the wolves. A dog that both men agree is not very smart. As Bill and Henry travel through the frozen, snow covered territory they notice the wolves following a little closer every day. Building fires at night to keep warm and to keep the wolves at bay, the men sense the animals closing in slowly but surely every day and every night. The next morning as Bill is feeding the dogs he notices the wolf (a she-wolf) amidst the sled dogs and is able to land a blow with a club. The following morning the men find another sled dog, Frog, gone. Unlike Fatty, the first dog to disappear, Frog was "no fool dog" and also the "strongest of the bunch." The men eat a very gloomy breakfast, harness the sled and repeat another day across the frozen Northland. After dinner, however, they decide to tie the dogs to stakes with leather straps to prevent another dog from running away to certain death. As they settle down for the evening the dogs become agitated and Bill and Henry look up to see the she-wolf wandering through the camp, eyeing the dogs. She is a decoy for the wolf pack, remarks Henry, luring the sled dogs away as food for the pack. After much discussion, the men decide it would be prudent to use some of the remaining ammunition to take care of the troublesome she-wolf. Left with only three dogs, the men start out the next morning only to meet more catastrophe as the sled overturns on a bad price of trail. Stuck between a tree trunk and a large rock, the men are forced to unleash the dogs to straighten the sled.

Legalization of Marijuana Should Not Happen Essay -- cannabis should no

The legalization of marijuana is a very controversial issue that is being debated across the United States. In the article "Going to Pot?," by Damon Linker, Linker attempts to persuade readers that legalizing of marijuana can cause more harm than help. This publication was released in November of 2001. Although two other writers, Richard Lowry and Andrew Sullivan, try to change readers beliefs Linker maintains his stance against marijuana. Without discrediting their facts he explains and defends why he feels they are wrong. The article is formal and although religion is not talked about, morals and society standards are questioned. Throughout the argument, Linker proves that effects of marijuana are detrimental to our society and will hinder social relations if legalized by our government. Linker is trying to sway the 34% of Americans who believe marijuana should be legalize to realize that more future problems will come from legalization. The audience Linker is reaching is primarily readers of the Religion and Public Life Monthly Journal. He is also trying to reach the 34% of Americans that approve the legalization of marijuana and the conservatives that seem to be shifting from prohibition to legalization. Linker focuses on today’s generation of parents and young adults because the choice will be in their hands soon. Society, as a whole, does not want marijuana to be legalized but as Linker states the attitudes appear to be shifting. The act of smoking marijuana is still perceived as bad and something that is looked down upon in society. The beliefs of people today are not the same as it was thirty years ago, and will continue to shift for times to come. Linker’s claims are logical and have basis. He p... ... article. This argument is good for the average American who knows little of the effects of marijuana. According to Linkers facts 66% of America still believe marijuana should not be legalized. This article is good for them because even if they were thinking of shifting opinions he proves that it would be wrong to legalize marijuana. Those Americans are the people that would agree with this argument because they want to believe that marijuana is harmful and should not be legalized. Obviously the other two authors and the 34% of America that believe marijuana should be legalized would disagree with this article. They could disagree with this continuously but the fact is that marijuana, however pleasurable it may be and seemingly less harmful than cigarettes, is still harmful in the long-term. The consequences of using and legalizing marijuana far outweigh the benefits.

Are cell phone is dangerous Essay

There are billions of people all over the world use cell phones. They use them for many different purposes, some use them for calling, or sending messages, others use may use them for logging into the net and chatting with friends. From my point of view, cell phones are very dangerous as they waste time and money, sometimes they lead to some sort of addiction, and they are dangerous to the human body. First of all, cell phones waste a lot of time and money. There are a lot of people especially teenagers who spend hours talking to their friends on phones which is also a waste of money. I see that talking to friends for hours weakens family ties. I know people who spend half of their salaries on cell phones bills while their children and their homes need this money. In addition, cell phones lead to addiction. I have a friend who suffers from chatting addiction and that`s because she spends most of her time chatting with her friends on Facebook or Yahoo messenger program. cell phones cause a  another kind of addiction which is sending messages addiction, I remember hearing, a woman in Opera Winfrey Show who sends messages even in the bathroom, and sleeps with the mobile in her hands. This woman nearly sends about three hundreds messages monthly or more. Furthermore, cell phones are very dangerous to the human body. Researchers say that cell phones send electric emancipations that cause cancer to the cells of the human body .As well as, they cause severe headache and harm our ears. Therefore, people shouldn`t sleep with their mobiles beside them, and it is better if you switch off your mobile before sleeping. To cut a long story short, cell phones` disadvatages out weigh its  advantages, I know that they become necessary in our daily schedule, but when it comes to driving it is not necessary.