Traffic congestion Essay Example for Free

Traffic congestion Essay Introduction Traffic congestion is one of the most compelling global problems especially in developed cities. London is among those cities which suffer from the traffic problems. According to the London city council, Londons population was 8. 17 million in 2011. By the year 2011, every 100 people in London owns 60-65 personal cars, which means cars have been the prior transportation tools for local people (Blythe, 2005). Frequently using cars as vehicle contributes to the traffic problems. As the rapid growth of population, the rate of car ownership would reach to a higher level hich is a severe test to the environment. According to Hickman et al (2010), Approximately 25% of carbon dioxide(C02) emissions is contributed by transport tools. Obviously, traffic problem is a magnificent cause of the environmental damage. Although some relevant policy has been implemented to reduce the congestion, traffic problems still exist across the capital with the growth of population and employment. (Transport Committee, 2008) According to Transport Committee (2008), Londons traffic speeds are below average speeds of global cities such as New York nd Singapore. Meanwhile, the population and the demands of Jobs in London are predicted to reach to a high level by 2025. The location of the additional Job will force a large number of people to go through the city at peak hours, which is a severe challenge to the local traffic situation. (Transport Committee, 2008) Thus, light rail transit systems (LRT) could be the ideal solution to traffic problem. However, the high cost might limit the scale of this method. Electronic toll collection system (ETC) is regarded as another option with relatively low cost.

The Donora Death Fog :: Air Pollution Environmental Issues Essays

The Donora Death Fog â€Å"D-Town!† Back home in Canonsburg, a small suburb outside of Pittsburgh, this is how we refer to Donora. We joke that the only thing in Donora is the roller skating rink, but even this is inaccessible to anyone who’s not a D-town native because when you are at the age to want to go roller skating you aren’t brave enough to enter into the Donora city limits. Only dedicated roller-skaters are brave enough to dare the elements of Donora. Of course, one, particularly a girl, would never think of going to Donora alone. But for me, I was never really that scared of Donora because my grandparents live nearby and we used to have dinner at the Ponderosa that has since closed. But, I never missed the opportunity to poke fun at that â€Å"rough† territory. Recently, I drove through D-town. The shops are boarded up. There’s graffiti everywhere. In addition to the roller rink there are a few bars and decrepit restaurants. I always assumed that it was the gi gantic Wal-mart that had caused this once thriving town to fall to shambles. But, this town, as I recently learned, was the site of the â€Å"worst recorded industrial air pollution accident in US history† (The Donora Fluoride Fog). This disaster intrigued me, so I decided to do some research regarding what happened. My investigation first led me to find that twenty people died from October 26-31, 1948 (Pennsylvania DEP). According to the Pennsylvania Department of Transportation website, the town population was about 14,000 at the time of the disaster. Devastatingly, about half-7,000-of those people became ill or hospitalized. My investigation led me to discover that this disaster was â€Å"created by unchecked industrial emissions and stagnant air conditions† (Donora’s Killer Smog Noted at 50). These conditions led to a smog fog hanging around the area. The American Steel & Wire Co., a subsidiary of the US Steel Group, was the local plant responsible for producing these emissions and conditions. It is also widely accepted that the weather conditions were prominent in producing the disaster. In October of 1998, spokespeople for the industry agreed that the disaster was unfortunate and tragic, but did not fail to note that, at the time of the disaster, clean air acts did not exist. If any good could come from this disaster it was the funding for research about clean air and the eventual passing of clean air acts and legislation.

Lebron Interview Analysis

With this decision Lebanon composed this essay in o deer to explain himself; to his Miami fans and the rest of the world. Lebanon does not want to be hated in Miami. In Lebanon James' homecoming article he misleads the reader; coming home does not reveal his motives, basketball championships remain the main cause for betray Months after Lebanon James finalized his decision to leave, sports analysts debt dated the true reasons behind his motives. Coming home eases Lebanon decision, but f ails to reveal the entire picture. Lebanon James plays basketball better than any man in the world d, he obviously cares if he plays on a good team or not.Lebanon wouldn't abandon a talented t am for a subpart squad. â€Å"l went to Miami because of Dead and (B. † (Para. 3). Lebanon first moved due to appeal of talented players. Lebanon's second decision mirrors his first m eve. Lebanon will continue to argue that he desires to return home due to his love for Cleveland d, but he's hiding the tr uth. In reality Cleveland homes a championship caliber basketball team. Cleveland future seems promising with young stars like Keri Irving and now Kevin Love. Lebanon realizes this and seizes the opportunity. Going home just adds to the glory of it all.Even Though Lebanon grew up in Ohio, he loved his time away in Miami. â€Å"l will always think of Miami as my second home† (Para. 2). Lebanon loved Miami; leaving sol Ely off being homesick makes no sense. Lebanon stated that he would not move anywhere without a beach in an interview before revealing his final decision. In case you didn't know, the re aren't any beaches in Cleveland. Lebanon decided to leave Miami due to the potential of T he Cavaliers. Lebanon expresses his desire to win an NAB championship once again, especial Ii for Ohio. Lebanon acts modest about The Cavaliers skill in saying â€Å"We're not ready eight now. (Paragraph 8) in attempt to ease the hate from Miami fans. Lebanon attempts t o downsize the team by labeling them young and inexperienced, but he also acknowledges the Eire talent. Doing this allows Lebanon to appeal to both crowds. Despite his best efforts most see through his attempt to mislead. Lebanon acts like his road to success will take years. Lebanon compares his move to Cleveland to his first move made in 2010. He go sees on to say â€Å"I wanton win next year, but I'm realistic. It will be a long process, much 10 anger than it was in 2010. My patience will get tested† (Para. ). Success will come early and will not be short lived.

How Does Regenerative Braking in Hybrid Cars Work

Hybrids and all-electric vehicles create their own power for battery recharging through a process known as regenerative braking (regen mode). Weve explained what regenerative braking is and how the process works in general terms, but many folks are interested in the deeper nuts and bolts of electricity generation. They understand that in a hybrid or all-electric vehicle the word regenerative, in terms of regenerative braking, means capturing the vehicles momentum (kinetic energy) and turning it into electricity that recharges (regenerates) the onboard battery as the vehicle is slowing down and/or stopping. It is this charged battery that in turn powers the vehicles electric traction motor. In an all-electric vehicle, this motor is the sole source of locomotion. In a hybrid, the motor works in partnership with an internal combustion engine. But that motor is not just a source of propulsion, its also a generator. Any permanent magnet motor can operate as either a motor or generator. In all-electrics and hybrids, they are more precisely called a motor/generator (M/G). But the technologically curious want to know more, and theyll often ask How, and by what mechanism or process, is the electricity created? Its a good question, so before we get started explaining how M/Gs and regenerative braking work in hybrids and electric vehicles, it is important to have basic knowledge about how electricity is generated and how a motor/generator functions.   So How Does a Motor/Generator Work in an Electric or Hybrid Vehicle? No matter the vehicle design, there must be a mechanical connection between the M/G and the drivetrain. In an all-electric vehicle, there could be an individual M/G at each wheel or a central M/G connected to the drivetrain through a gearbox. In a hybrid, the motor/generator could be an individual component that is driven by an accessory belt from the engine (much like an alternator on a conventional vehicle--this is how the GM BAS system works), it could be a pancake M/G that is bolted between the engine and transmission (this is the most common setup--the Prius, for example), or it could be multiple M/Gs mounted inside the transmission (this is how the two-modes work). In any case, the M/G has to be able to propel the vehicle as well as be driven by the vehicle in regen mode. Propelling the Vehicle with the M/G Most, if not all, hybrids and electrics use an electronic throttle control system. When the throttle pedal is pushed, a signal is sent to the onboard computer, which further activates a relay in the controller that will send battery current through an inverter/converter to the M/G causing the vehicle to move. The harder the pedal is pushed, the more current flows under the direction of a variable resistance controller and the faster the vehicle goes. In a hybrid, depending upon load, battery state-of-charge and the design of the hybrid drivetrain, a heavy throttle will also activate the internal combustion engine (ICE) for more power. Conversely, lifting slightly on the throttle will decrease current flow to the motor and the vehicle will slow down. Lifting further or completely off the throttle will cause the current to switch direction — moving the M/G from motor mode to generator mode — and begin the regenerative braking process. Regenerative Braking: Slowing the Vehicle and Generating Electricity This is really what the regen mode is all about. With the electronic throttle closed and the vehicle still moving, all of its kinetic energy can be captured to both slow the vehicle and recharge its battery. As the onboard computer signals the battery to stop sending electricity (via the controller relay) and start receiving it (through a charge controller), the M/G simultaneously stops receiving electricity for powering the vehicle and starts sending current back to the battery for charging. Remember from our discussion on electromagnetism and motor/generator action: when an M/G is supplied with electricity it makes mechanical power, when its supplied with mechanical power, it makes electricity. But how does generating electricity slow the vehicle? Friction. Its the enemy of motion. The armature of the M/G is slowed by the force of inducing current in the windings as it passes over the opposing poles of the magnets in the stator (its constantly battling the push/pull of the opposing polarities). It is this magnetic friction that slowly saps the vehicles kinetic energy and helps scrub off speed.