Positive Train Control Term Paper Example | Topics and Well Written Essays - 2500 words

Positive Train Control - Term Paper Example Implementation of PTC is anticipated to range over the total rail track mileage of 70,000. PTC is basically a technology of train control that is processor or communication based meant to reduce the frequency of collisions between trains, derailments upon over-speeding, attacks into the defined zones of work, and a train’s improper movement through the main line switch. The systems of PTC are needed to execute various types of functions. There is a wide range of PTC systems that vary depending upon a number of factors that include but are not limited to the level of sophistication and complexity of the functionality and automation implemented by them, their wayside system which can be cab signaled, block signaled, or non-signaled, the kind of system architecture used, and the level of control they can achieve over the train. Use of the PTC system in the railroad industry has increased the safety of traveling by train manifolds. The Federal Railroad Administration (FRA) support s all rail carriers that are required to install and implement the PTC system as per law and others that implement the PTC system voluntarily, by means of a mix of project safety measures, regulatory reforms, funds, and technological development. The final rule encompassing the requirements of PTC was published by FRA on 15 January 2010, whereas the final rule amendments were published on 27 September 2010 and subsequently on 14 May 2012. 41 railroads initially deposited the plans of implementation that were reviewed by FRA but denied the approval of all prior to the statutory deadline of 90 days for review. Upon the resubmission of all 41 implementation plans, FRA finally approved 24 unconditionally, 1 conditionally, gave provisional approval to 14 implementation plans that were deposited with the Notices of Product Intent that were supposed to be resubmitted along with a development plan of PTC in 270 days, while 2 plans were disapproved. However, the staff of FRA sustained workin g with them to formulate approvable plans. Currently, FRA is collaborating with two more railroads that were not identified before in order to formulate and deposit successful plans of implementation. The fundamental idea in PTC is that the safety of train’s journey is enhanced by making it aware of its location and guiding it so that it stays on the right track. PTC achieves these functions by making use of networks of communication. â€Å"PTC systems are comprised of digital data link communications networks, continuous and accurate positioning systems such as NDGPS, on-board computers with digitized maps on locomotives and maintenance-of-way equipment, in-cab displays, throttle-brake interfaces on locomotives, wayside interface units at switches and wayside detectors, and control center computers and displays† (Poor, Lindquist, and Wendt, 2009). This prevents the train from making unsafe movements. PTC systems can work in both signaled and dark territories and may a lso use the GPS to guide the train. One of the main goals of FRA is, â€Å"To deploy the Nationwide Differential Global Positioning System (NDGPS) as a nationwide, uniform, and continuous

Organizational Culture Assignment Example | Topics and Well Written Essays - 750 words

Organizational Culture - Assignment Example During the recruitment phase the prospective employees are required to fill firms having features like cross-word puzzles, so as to extend to the future employees the idea of what Zappos is all about. During the encounter phase Zappos resorts to an extensive orientation program to immerse the new employees into the quintessential Zappos values. The company offers the new employees a $1000 reward in case they decide not to join Zappos. This gives the new employees an idea of the kind of commitment to organizational values that Zappos expects of them. During the last phase of organizational socialization that is during the change and acquisition phase, Zappos allows the employees to evince commitment to its essential value of customer service in an extempore and innately natural manner. The Zappos employees are not expected to resort to any script or format while dealing with the customers. Zappos also offers happy hours to its employees when they engage in team activities and recreati on. This allows the employees to develop commitment to the Zappos values in their own unique and natural manner. 2. There is no denying the fact that the success of a company to a large extent depends on its employees’ capacity to gel their personal beliefs and values with the organizational values. Zappos has a concerted strategy aimed at assuring that its organizational values fit with the values of the people it hires. Zappos has an extensive recruitment program which seriously digs into the values of the prospective employees to access as to what extent the values of a future employee blend with the Zappos’ organizational values. Once the employees are recruited, Zappos conducts an orientation programs to make sure that the new employees do get an idea of the essential Zappos values woven around customer service and ingenuity. Zappos offers to every new employee an incentive of $1000, in case one decides to quiet right at the start. This strategy extends to Zappos an opportunity to access as to what extent the values of the recruited employees blend with the organizational values. This also helps Zappos configure that to what extent an employee is comfortable with and committed to the organizational values. Part B 1. A few years back I had a chance to work at the local Sugar Sweet Bakery. It was a Big Bakery that employed around 67 people. Extending a personalized service to each and every customer happened to be a core value at Sugar Sweet Bakery. To embed this value in the organizational culture, Mr. Butler, the owner of the Bakery made it a point to role model the core values that this business was committed to. Each and every employee at Sugar Sweet was personally greeted by Mr. Butler every morning as one entered the Bakery. All employees were expected to have their breakfast every morning with Mr. Butler and other managers at the Bakery premises. During breakfast employees were encouraged the share their experiences and concerns with ea ch other and the management. The objective was to give way to a family like atmosphere at the organization. Consequently the employees carried this acquired value of personalized care to the customers and extended a personalized and customized service to each and every customer that visited the Sugar Sweet Bakery. 2. Though the family like organizational atmosphere at this

Negative Absolute Temperature Thermodynamics

Negative Absolute Temperature Thermodynamics T.H. Tennahewa Thermodynamics and Statistical mechanics at Negative Absolute Temperature We define the temperature, T; by in here S stands for Entropy which describes the measure of disorder in the system and U for Internal energy. In here x stands for the partial differentiation that should hold constant in the thermodynamic equation relating TdS and dU. this relation comes from the first law of Thermodynamics. That is; ; We can define temperature with relating Enthalpy (H) also. That is in here too y stands for the partial differentiation that should hold constant in the thermodynamic equation relating TdS and dH. Below is the derivation of above equation. We called absolute temperature as a temperature where on the Kelvin scale 0 K as the absolute zero point, where all motion in a classical gas would stop. Most systems, including a classical gas are limited to positive absolute temperatures. In order to be able to reach negative temperatures, a system needs to possess an upper bound for the energy of its particles, which is a maximal possible energy a particle of the system can have. This limit is not an external limit in the sense that there is just no more energy available. It is an internal limit the particles cannot absorb more energy even if there is plenty available. It is important to note that the negative temperature region, with more of the atoms in the higher allowed energy state, is actually warmer than the positive temperature region. If this system were to be brought into contact with a system containing more atoms in a lower energy state (positive temperatures) heat would flow from the system with the negative temperat ures to the system with the positive temperatures. By the definition of temperature we can describe above figure. If the energy in the system is minimum (Emin), all particles are in the lowest possible energy state and the entropy is zero. The curve is vertical at this point with an infinite slope and temperature is therefore zero. If the energy increases, the particles begin to occupy higher energy states, and the entropy increases. There are, however, always more particles at low energies than at high energies this is same as the usual Boltzmann distribution. (Figure 2 below) The slope of the entropy versus energy curve decreases and the temperature therefore increases. At some point, when there is enough energy in the system, the particles distribute equally over all energy states. Therefore the disorder and the entropy are maximum. The curve is completely flat at this point, with a slope of zero, and the temperature is therefore infinite. If the total energy in the system is further increased, more particles will occupy high energies than low energies this is same as the inverted of the Bolt zmann distribution. Because the energy distribution becomes narrower again, disorder and entropy starts to decrease. This is not a usual behavior because usually entropy increases with increasing energy. The slope of the curve is negative in this region and therefore the absolute temperature is negative. If the energy in the system is maximum (Emax), all particles are at their maximum possible energy. The entropy is again zero. The curve is again vertical therefore the temperature is again zero, but this time it is negative values. Thus, while a temperature of positive and negative infinity is physically identical, temperatures of positive and negative zero are very different. Because of that we could write temperature range as +0 K, +300 K, , +∞ K, −∞ K, , −300 K, , −0 K. Figure 2- The Maxwell- Boltzmann distribution In the Carnot cycle of a heat engine heat absorbed from the hot reservoir and heat rejected to the cold reservoir while work done by the system. In that case we define the efficiency of the process as, In here Q1 is a heat absorbed at temperature T1 and Q2 is a heat rejected at temperature T2. In heat engine T2 / T1 2 / T1 > 1, therefore efficiency is negative and can be very large. In this case work has to be supplied to maintain the cycle. It should be noted that when Carnot cycle is operated between two negative temperatures that is work is done by the machine while heat absorbed from cold reservoir and rejected to hot reservoir. Efficiency of the system is not only positive but it is also less than unity. Thus at both positive and negative temperatures cyclic heat engines which produce work have efficiencies less than unity that is they absorb more heat than produced work. Second law of thermodynamics should have to modify to use with this kind of Carnot cycle. In there, entropy formulation and Clausius statement remain unchanged and Kelvin-Plank formulation has to be changed. They are mentioned below. Entropy formulation The entropy of a system is a variable of its state and the entropy of an isolated system can never decrease. Clausius Statement It is impossible to construct a device operating in a closed cycle that will produce no other effect than the transfer of heat from a cooler to hotter body. Kelvin- Plank formulation It is impossible to construct an engine, which is operating in a cycle produces no other effect except to external heat from a single reservoir and do equivalent amount of work. Modified statement: It is impossible to construct an engine that will operate in a closed cycle and produce no effect other than the extraction of heat from a positive temperature reservoir with the performance of an equivalent amount of work or the rejection of heat into a negative temperature reservoir with the corresponding work being done on the engine. Carathà ©odory form In any neighborhood of any state there are states that cannot be reached from it by an adiabatic process. Both first and second laws of thermodynamics can be used at negative temperatures as at positive ones to derive other thermodynamic relations. From these laws it is interpreted that the difficulty of heating a hot system at negative temperatures is analogous to the difficulty in cooling a cold system at positive temperature. The important requirements for thermodynamical system to be capable for negative temperature are: The elements of the thermodynamical system must be in thermodynamical equilibrium among themselves in order to describe the system by temperature. There must be an upper limit of the possible energy of the allowed states of the system. It is need a lower bound for the energy in order to get positive temperatures and an upper bound in order to get negative temperatures. The system must be thermally isolated from all systems which do not satisfy both of the above conditions. To satisfy the second condition negative temperatures are to be achieved with a finite energy. In thermal equilibrium the number of elements in the mth state is proportional to the Boltzmann factor; here Wm is energy of the mth state. Boltzmann distribution function which is formed using Boltzmann factor is given below. In negative temperature case when Wm increases with that Boltzmann factor increases exponentially therefore high energy states are more occupied than low energy states. As a result of this we could say that without an upper limit to the energy negative temperatures could not be achieved with a finite energy. Since most of the systems do not satisfy this conditions negative temperatures are occurs rarely. Spin systems sometimes form the thermodynamic systems which can describe by using temperature. In there for a system of electron spins in a lattice, a temperature such that the population of the energy levels of the spin system is given by the Boltzmann distributionwith the spin temperature. To achieve thermodynamic equilibrium various nuclear spins must interact among themselves. This happened due to nuclear spin-spin magnetic interaction. Subatomic particles like electrons, protons and neutrons can be imagined as spinning on their axes. In many atoms these spins are paired against each other, such that the nucleus of the atom has no overall spin. In some atoms the nucleus has shown overall spin. The rules for determining the net spin of a nucleus are given below; If the number of neutrons  and  the number of protons are both even, then the nucleus has  NO  spin. (Classical Particles) If the number of neutrons  plus  the number of protons is odd, then the nucleus has a half-integer spin (i.e. 1/2, 3/2, 5/2) (Fermions) If the number of neutrons  and  the number of protons are both odd, then the nucleus has an integer spin (i.e. 1, 2, 3) (Boson) It is defined in Quantum mechanics that a nucleus of spinIwill have 2I+ 1 possible orientations. A nucleus with spin 1/2 will have 2 possible orientations. In the absence of an external magnetic field, these orientations are of equal energy. If a magnetic field is applied, then the energy levels split. When the nucleus is in a magnetic field, the initial populations of the energy levels are determined by thermodynamics, as described by the Boltzmann distribution. It means that†the lower energy level will contain slightly more nuclei than the higher level†. It is possible to excite these nuclei into the higher level with electromagnetic radiation. The frequency of radiation needed is determined by the difference in energy between the energy levels. This spin-spin process can be characterized by using relaxation process. Nuclei in the higher energy state return to the lower state by emitting the radiation. At radio frequencies, re-emission is negligible. There are two main relaxation processes; Spin lattice (longitudinal) relaxation Spin spin (transverse) relaxation Spin lattice relaxation (T1) Nuclei which are in a sample create a complex magnetic field. The magnetic field caused by motion of nuclei within the lattice is called thelattice field. This lattice field has many components. Some of these components will be equal in frequency and phase to the Larmor frequency of the nuclei of interest. These components of the lattice field can interact with nuclei in the higher energy state and cause them to lose energy returning to the lower state. The energy that a nucleus loses increases the amount of vibration and rotation within the lattice resulting in a tiny rise in the temperature of the sample. The relaxation time,T1(the average lifetime of nuclei in the higher energy state) is dependent on the magnetogyric ratio of the nucleus and the mobility of the lattice. As mobility increases, the vibrational and rotational frequencies increase, making it more likely for a component of the lattice field to be able to interact with excited nuclei. However, at extremely high mobilities, the probability of a component of the lattice field being able to interact with excited nuclei decreases. Spin spin relaxation (T2) This is describing the interaction between neighbouring nuclei with identical precessional frequencies but differing magnetic quantum states. In this case, the nuclei can exchange quantum states; a nucleus in the lower energy level will be excited, while the excited nucleus relaxes to the lower energy state. There is nonetchange in the populations of the energy states, but the average lifetime of a nucleus in the excited state will decrease. This can result in line-broadening. Most of the nuclear systems don’t satisfy the conditions in negative temperatures. By looking at all these things we can conclude that although the phenomena of negative temperature is a fully valid concept in thermodynamics and statistical mechanics they have less important than phenomena of positive temperature. 1

Pros and cons of the Death Penalty Essay

Capital Punishment, legal infliction of death as a penalty for violating criminal law. Methods of execution have included such practices as crucifixion, stoning, drowning, burning at the stake, impaling, and beheading. Today capital punishment is typically accomplished by lethal gas or injection, electrocution, hanging, or shooting. The death penalty is the most controversial penal practice in the modern world. The United States stands apart from the general trends on capital punishment. It is the only Western industrialized nation where executions still take place. Furthermore, it is the only nation that combines frequent executions with a highly developed legal system characterized by respect for individual rights. Some of the pros and cons are as follows: Pros- Just Punishment- A punishment is just if it recognizes the seriousness of the crime. â€Å"Let the punishment fit the crime† is a generally accepted and sound precept. In structuring criminal sentences, society must determine what punishment fits the premeditated taking of innocent human life. To be proportionate to the offense of cold-blooded murder, the penalty for such an offense must acknowledge the inviolability of human life. Without a death penalty, the criminal law’s penalties will essentially â€Å"top out† and will not differentiate murder from other offenses. Only if the sentencing structure allows for a substantially greater penalty for murder will the range of penalties fully reflect the seriousness of ending the life of an innocent human being. Deterrence- The death penalty is also justified because of its deterrent effect, which saves the lives of innocent persons by discouraging potential murderers. Logic supports the conclusion that capital punishment is the most effective deterrent for premeditated murders. A capital sentence is  certainly a more feared penalty than a prison term. The lengths to which convicted murderers go to avoid imposition of this sentence clearly demonstrates this fact, as do interviews with prison inmates. To be sure, the death penalty does not deter all murders. But because a capital sentence is more severe than other penalties, it is reasonable to assume that its existence will lead at least some potential murderers to decide against risking execution. As the Supreme Court has observed, â€Å"There are carefully contemplated murders, such as the murder for hire, where the possible penalty of death may well enter into the cold calculus that precedes the decision to act.† Incapacitation- Capital punishment also serves to effectively prevent murderers from killing again. This incapacitation effect is particularly important because of the continuing risk posed by those who have already taken a human life. For example, according to data from the Bureau of Justice Statistics, of 52,000 state prison inmates serving time for murder in 1984, an estimated 810 had previously been convicted of murder. Had some of these murderers been given the death penalty for their first murders, innocent people would have been spared. . Only a capital sentence can permanently end the threat to others posed by the most serious murderers. The death penalty gives closure to the victim’s families who have suffered so much. It provides a punishment and deterrent for someone who’s already sentenced to life in prison. Prisoner parole or escapes can give criminals another chance to kill. Cons- Risk to the Innocent- The risk that an innocent person might be executed, Unlike all other criminal punishments, the death penalty is irrevocable,(IRREVERSIBLE) CAPITAL PUNISHMENT COSTS MORE THAN INCARCERATION A murder trial normally takes much longer when the death penalty is at issue than when it is not. Litigation costs – including the time of judges, prosecutors, public defenders, and court reporters, and the high costs of briefs – are mostly borne by the taxpayer. A 1982 study showed that were the death penalty to be reintroduced in New York, the cost of the capital trial alone would be more than double the cost of a life term in prison. It is barbaric and violates the â€Å"cruel and unusual† clause in the Bill of Rights,some people believe. We as a society have to move away from the â€Å"eye for an eye† revenge mentality if civilization is to advance. It sends the wrong message: why kill people who kill people to show killing is wrong. Some jury members are reluctant to convict if it means putting someone to death. The prisoner’s family must suffer from seeing their loved one put to death by the state. It is useless in that it doesn’t bring the victim back to life. The death penalty is racially biased against African Americans Statistical evidence conducted on cases of similar crimes found that African American defendants are over four times as likely to be executed as their White counterparts. A similar study noted that White defendants face almost no chance of execution when their victim is African-American. While African Americans make up only 13% of the U.S. population, over 40% of death-row inmates are African-American. In light of these gross inequalities, the continuation of capital punishment constitutes egregious discrimination. it is also true that those on death row come disproportionately from low-income and high-crime geographic areas. That such areas are disproportionately  populated by African Americans is a tragic correlation, painting a troubling portrait of a nation that lacks equality. Mistakes can be made, Advances in forensic medicine and DNA testing are leading to more and more exoneration’s of convicted criminals.

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Princess Diana - 1253 Words

One year ago, the death of a princess brought an entire world to tears. The wounds are slowly healing and the grief is less painful. What remains are the lessons that can be learned from a phenomenon that few can entirely forget. At the time it was a mystery. A divorced member of the royal family of a medium-sized European nation dies in a banal car accident in Paris, and for a week the sun, moon and stars are knocked off their appointed tracks. Within days, Europe suffers a shortage of cut flowers as tens of thousands of bouquets are laid before the house of the victim. Demand for newsprint soars; the funeral, watched live on television throughout the world, attracts an audience of 1 billion. A few years later, the mystery remains.†¦show more content†¦97) Children were Dianas delight, she always wanted a little girl. When one little eight-year-old girl Danielle first met the princess, she had no idea of the identity of the special person who was to visit the Rose Ward of Londons Royal Brampton Hospital, where she was lying ill with an irregular heartbeat. Danielle thought it was going to be Alan Shearer. It was, in fact, Diana, paying a private visit to the hospital to see a patient. Diana visited Nepal to see for herself the type of fieldwork in which the Red Cross was involved. As well as her often-unnoticed help at British hospitals, Diana also famously helped the work of Mother Theresa of Calcutta and Imran Khan, the former Pakistani cricket hero, with his charity cancer hospital. ‘This world has few people like Diana, Imran Khan said, ‘who work so devotedly for the well-being of the poor, deprived and down-trodden. (2, page 103) Dianas most recent campaign was against landmines, which really engaged her passion. How, she was asked, had she got involved in the first place? ‘A lot of information started landing on my desk about landmines, and I suppose the pictures were so horrificÂ…that I felt perhaps if I could be part of a team to raise the profile around the world, it would help. Film director Lord Attenborough was a vital link, too: ‘He invited me to the film premiere of In Love and War, which is raising money for the British Red Cross landmines appeal. So it seemedShow MoreRelatedPrincess Diana 2268 Words   |  10 Pagesextravagant. The whole palace was made of the finest materials, it was beautiful. The roof was even made of gold. Despite the royal family’s golden exterior with love for one another and their children, I saw the real Prince and Princess of Wales. I often had time to talk to Princess Diana, although she preferred when I called her Di ( Tompson 1). While Diana’s life was cut too short, every minute that she was alive was exciting, the outfits, the press, and the charities. People could not get enough of herRead More Princess Diana Spencer1421 Words   |  6 PagesPrincess Diana Spencer As I relax on a Sunday evening, breathe in fresh air before I enter my chamber, I catch a glimpse of something magically beautiful. With a long silk blue dress and a pearl-diamond tiara on her golden hair, the Lady, the Princess, the beauty of the world walks down the steps to the cheering crowds. She gives hope to her people when there is none. Sitting here, I feel her warm smile full of love and joy. This is my Diana, the light of this world! Diana’s childhood was fullRead MorePrincess Diana Essay534 Words   |  3 PagesPrincess Diana Princess Diana, also known as Princess of Wales was born on July 1, 1961 at Park House near Sandringham, Norfolk. Her parents, who were married in 1954, were separated when Diana was 13 years old in 1967. Their marriage was dissolved 2 years later in 1969. Dianas mother later married Earl Spencer, who was the Countess of Dartmouth in 1976. Diana was living with her dad with her siblings Sarah, Jane, and Charles. She lived there until her grandfather, Earl Spencer the 7thRead More Princess Diana Essay1065 Words   |  5 PagesThroughout Princess Diana’s lifetime she loved, cared, and helped others along the way. She had many accomplishments in life. Such as her children and her many organizations. nbsp;nbsp;nbsp;nbsp;nbsp;Lady Diana Frances Spencer was born on July 1, 1961 at Park House, a residence on the royal estate at Sandringham. She was the third of four children and the youngest daughter. Diana was born to her father Edward John Spencer Viscount Althorp and mother Frances Roche Spencer (King 27). Diana sharedRead MoreEssay on Princess Diana1723 Words   |  7 Pagesyielding herself from the constant harassment and persistence. Princess Diana of Wales always knew how to make an entrance. Rich, poor, famous, and obscure gathered around for a glimpse of the famous Diana, hoping to see her beauty, hoping to see the elegance she carried, hoping for one single glance in their direction. Through all movies and documentaries exposed, the knowledge of Princess Diana has grown extensively to me. Princess Diana’s journey through the media begins with the accident thatRead MoreEssay Princess Diana1202 Words   |  5 Pages One year ago, the death of a princess brough t an entire world to tears. The wounds are slowly healing and the grief is less painful. What remains are the lessons that can be learned from a phenomenon that few can entirely forget. At the time it was a mystery. A divorced member of the royal family of a medium-sized European nation dies in a banal car accident in Paris, and for a week the sun, moon and stars are knocked off their appointed tracks. Within days, Europe suffers a shortage of cut flowersRead MorePrincess Diana Essay957 Words   |  4 PagesHearts Throughout her life all eyes were always on Princess Diana. Millions came to identify with her and, when she died, they felt as though they have lost a best friend. Princess Di was known across the world as â€Å"The People’s Princess† and â€Å"The Queen of Our Hearts†. She was one of the most admired and relatable princesses to society. Through her charity and her life struggles, many people can admire and relate to Princess Diana. Princess Diana was involved in nearly 100 charities during her lifeRead More Princess Diana Essay2975 Words   |  12 Pages Princess Diana was born The Honorable Diana Frances Spencer on July 1, 1961. She was the third female child to Viscount and Viscountess Althorp. Diana had two older sisters, Sarah and Jane and one younger brother, Charles. Her family was well off and Diana had a privileged childhood. The Spencer’s made their money as successful sheep traders in the 15th century. With their fortune they built Althorp House in Northamptonshire and acquired a family crest and motto – amp;quot;God defend the rightamp;quot;Read MorePrincess Diana Essay1384 Words   |  6 PagesPrincess Diana Diana Spencer was born July 1, 1961. This date was the start of one of the most remarkable individuals in the world . She was once quoted as saying, One minute I was a nobody the next minute I was Princess of Wales, mother ,member of the royal family and it was too much for one person to handle (Morton story,104). The Princess of Wales struggled throughout her life due to bulimia, an unhappy marriage, and the media. Dianas astrologer, Felix Lyle, quotedRead MorePrincess Diana Essay example1691 Words   |  7 Pagesthe world. Princess Diana influenced millions of people from all over the world, and her legacy will remain forever. Lady Diana Frances Spencer was born at home on July 1, 1961, in Norfolk, England (Morton 70). Her parents were very ashamed that she was a girl. They wanted a boy very badly to keep the Spencer name (Morton 71). Diana had two older sisters and one younger brother. She was always the closest to her brother, Charles, and admired him strongly (Vickers 160). As a child, Diana was somewhat