Conservative Perspectives on Gun Control

Conservative Perspectives on Gun Control The second amendment to the U.S. Constitution is perhaps the most important amendment in the Bill of Rights, if not the entire document. The second amendment is all that stands in the way between American citizens and total chaos. Without the second amendment, nothing would prevent a duly elected president (who is also the nations commander-in-chief) from declaring martial law and using the nations military forces to systematically usurp and dismantle the remaining civil rights of its citizens. The second amendment is Americas greatest defense against the forces of totalitarianism. Interpretation of the Second Amendment The simple wording of the second amendment has been widely interpreted, and gun-control advocates have sought to obfuscate the language in order to further their agenda. Perhaps the most controversial aspect of the amendment, upon which gun-control advocates have rested much of their arguments is the part that reads a well-regulated militia. Those who seek to erode the amendment, claim that the right to bear arms is extended solely to militias, and since both the number of militias and the effectiveness of them have diminished since the 1700s, the amendment is now moot. Local and state government bodies have frequently sought to strip the amendment of its power by imposing draconian regulations and requirements. For 32 years, gun owners in Washington D.C. were not legally permitted to own a handgun or carry one within the districts territory. In June 2008, however, the Supreme Court ruled 5-4 that the districts law was unconstitutional. Writing for the majority, Justice Antonin Scalia observed that regardless of whether violent crime is a problem, the enshrinement of constitutional rights necessarily takes certain policy choices off the table ... Whatever the reason, handguns are the most popular weapon chosen by Americans for self-defense in the home, and a complete prohibition of their use is invalid. Perspectives of Gun Control Advocates While handguns were the issue in Washington, D.C., gun control advocates elsewhere have decried the access to and usage of fully-automatic weapons and other high-powered firearms by the general public. Theyve sought to limit or even prohibit ownership of these so-called assault weapons in a misguided attempt to protect the public. In 1989, California became the first state to pass an outright ban on fully-automatic rifles, machine guns and other firearms considered to be assault weapons. Since then, Connecticut, Hawaii, Maryland, and New Jersey have passed similar laws. One reason gun control opponents are so adamant about keeping these firearms on the open market is because the access to weapons by the American military has far outpaced the access to weapons by the American public in both number and power. If a nation is unable to defend itself against the forces of tyranny within its government because the right to bear arms is so badly eroded, it undermines the spirit and intention of the second amendment. Liberals also advocate legislation restricting the types of ammunition available for firearms, as well as the types of people who can own them. Ex-cons or people with prior mental illnesses, for example, are prohibited from owning or carrying guns in certain states, and the Brady Bill, which became law in 1994, mandates prospective gun owners undergo a five-day waiting period so local law enforcement authorities can conduct background checks. Every regulation, restriction or law that infringes upon Americans right to keep and bear arms, prevents America from being a country that is truly free.

Rivalry Between Beijing vs. Shanghai

Rivalry Between Beijing vs. Shanghai Beijing and Shanghai are arguably China’s two most famous and most important cities. One is the center of government, the other the center of modern commerce. One is steeped in history, the other is a glittering tribute to modernity. You might imagine that the two fit together like yin and yang, complimenting each other, and maybe that’s true... but they also hate each other. Beijing and Shanghai have a fierce rivalry that’s been going on for decades, and it’s fascinating. What Shanghai Thinks of Beijing and Vice Versa In Shanghai, people will tell you Beijing ren (Ã¥Å'â€"ä º ¬Ã¤ º º, â€Å"Beijingers†) are arrogant and uncouth. Although the city is host to more than 20 million people, Shanghai’s denizens will tell you they act like peasants- friendly, perhaps, but blustery and uncultured. Certainly not as refined and fashionable as Shanghaiers! â€Å"They [Beijingers] smell like garlic,† one Shanghai resident told the LA Times in an article on the rivalry. In Beijing, on the other hand, they’ll tell you that Shanghai people only care about money; they’re unfriendly to outsiders and selfish even among themselves. Shanghai men are said to place too much importance on business while being impotent pushovers at home. Shanghai women are supposedly bossy dragon ladies who push their men around whenever they’re not too busy spending their money shopping. â€Å"All they care for is themselves and their money,† a Beijinger told the LA Times. When Did the Rivalry Originate? Although China has dozens of huge cities these days, Beijing and Shanghai have played a major role in China’s culture for centuries. At the beginning of the twentieth century, Shanghai clearly had the upper hand it was the center of Chinese fashion, the â€Å"Paris of the East†, and Westerners flocked to the cosmopolitan city. After the revolution in 1949, though, Beijing became the center of China’s political and cultural power, and Shanghai’s influence waned. When China’s economy was opened up following the Cultural Revolution, Shanghai’s influence began to rise again, and the city became the heart of Chinese finance (and fashion). Of course, it’s not all macroeconomics and geopolitics. Although denizens of both cities would like to believe their cities are more influential, there is also a grain of truth to the stereotypes and jokes that get passed around; Shanghai and Beijing do have very different cultures, and the cities look and feel different. The Rivalry Today These days, Beijing and Shanghai are considered mainland China’s two greatest cities, and although the government being located in Beijing means that Beijing will probably have the upper hand for the foreseeable future, but that hasn’t stopped the two from competing. The Beijing Olympics in 2008, followed by Shanghai’s World Expo in 2010, have been a great source of fodder for comparative arguments about the virtues and faults of the two cities, and denizens of both will argue it was their city that put on the better show when they were on the world stage. Of course, the rivalry also plays out in professional sports. In basketball, a match between the Beijing Ducks and the Shanghai Sharks can be counted on to be contentious, and both teams are among the best in the league historically, though it has been more than a decade since the Sharks made an appearance in the finals. In soccer, Beijing Guoan and Shanghai Shenhua duke it out for bragging rights each year (though again, Beijing has had more recent success than Shanghai in the league). It’s unlikely that Beijingers and Shanghaiers will ever see totally eye to eye. It’s worth noting that the Beijing versus Shanghai feud sometimes even extends the ​city’s expatriate communities, so if you’re looking for a Chinese city to live in, choose wisely.

Use and analyse the use of a range of Lean tools ( Engineering Essay

Use and analyse the use of a range of Lean tools ( Engineering Business ) - Essay Example Bicheno & Holweg (2008) distinguished between four types of flexibility, namely process flexibility, product flexibility, volume flexibility and labour flexibility. These are detailed in the table below. The organisation can then devise its strategy according to the type of flexibility desired. Some other tools are histograms, Pareto charts, cause and effect diagrams, flow charts and control charts. It is pertinent to point out that strictly; lean is not merely a set of tools. Individual tools are useful for specific purposes, but they are designed to be used together in such a way that increases overall efficiency. The combination and synchronisation of tools allows for a wide range of strategic options. The improvement in competitiveness is made possible by â€Å"an end-to-end value stream† (Bicheno & Holweg, 2008). It is therefore a complete system, which involves processing for enhancing value by reducing waste. Lean tools serve to be applied such that they improve specific and overall efficiency. Mistakes could be made at any time during ordering, but most of these tend to be the result of human errors. It is important to prevent mistakes, for example because it could lead to producing defective parts, giving the wrong service, and ultimately to customer dissatisfaction. Moreover, â€Å"mistakes in one area have consequences in all others† (Nicholas & Steyn, 2008: 485). The alternative could be to make inspections but this itself is not mistake proof, and it is also an inefficient method. Preventing mistakes could eliminate the possibility of failures, and thus producing wastes. This could in turn avoid time wasting and prevent unnecessary costs. Mistakes with an order can be prevented by implementing a safety mechanism at any stage of the ordering process where mistakes would be likely to occur. The Japanese term for making processes protected from mistakes is ‘poka yoke’ (ãÆ' Ã£â€š «Ã£Æ' ¨Ã£â€š ±), which

The Arabian Peninsula Country and Sovereignty Essay

The Arabian Peninsula Country and Sovereignty - Essay Example Israel remains the only separate country on the Peninsula. The new APC has over 25% of the world’s known oil reserves in its territory. The new country is flexing its muscle and claiming its sovereign rights over the water and in the exclusive zone that overlap into other nation’s areas in the Persian Gulf, the Arabian Sea into the Indian Ocean, the Red Sea and the Mediterranean Sea. The APC has restricted the use of the airspace it is claiming to all western nations and threatens to shoot down any aircraft whether military or commercial that flies into its airspace. Further, fearing western satellites spying on its territory from space, the APC claimed territorial sovereignty above its country into space and threatens to shoot down any satellites that fly over its territory. It is unclear if the APC has the technology to fulfill this threat but there are missile exports from Russia and China that may be able to knock out a satellite in orbit. The APC has announced plan s to increase its standing army to over 50,000 troops and is beginning construction of a deepwater naval fleet to project its influence in the region. 2.0. Statement of the Problem Some of the fundamental issues pertaining to the situation are as follows. First, can the APC claim sovereignty after Yemen, Oman, the United Arab Emirates, Saudi Arabia, Qatar, Kuwait, Iraq, Jordan, Lebanon, and Syria sought to consolidate themselves into a single nation to be known as the APC? Second, what will be scope and limits of the claim on sovereignty if this is the case? Third, up to what extent can the APC claim sovereignty over its airspace and into space? Finally or fourth, what are the threats posed by the APC on the United States of America? 3.0. Proposed USA Position: Sovereignty and History/Scope in International Law Jean Bodin first systematically analyzed the doctrine of sovereignty in 1576 in the work, Six Livres de la Republique (Shaw, 21). In the Bodin notion of sovereignty, sovereig nty is only â€Å"subject to the law of God and of nature† as the â€Å"state was regarded as above the law† (Shaw, 21). In the age of enlightenment and as the early theories were influenced by the ideas of Thomas Aquinas who maintained that â€Å"Natural Law formed part of the law of God, and was the participation by rational creatures in Eternal Law,† the notion of state sovereignty may have been subject to reason or what were considered â€Å"reasonable† (Shaw, 22). Later that time, â€Å"elements of both positivism and naturalism† appeared in the work of Vattel (1714-67), a Swiss lawyer, who â€Å"introduced the doctrine of the equality of states into international law, declaring that a small republic was no less sovereign than the most powerful kingdom† (Shaw, 26). At the same time, the idea of natural laws gave way to the concept of natural rights (Shaw, 26). Shaw asserted that international law is based on the concept of the state tha t in turn â€Å"lies upon the foundation of sovereignty, which expresses internally the supremacy of government institutions and externally the supremacy of the state as the legal person† (487). Sovereignty â€Å"is founded upon the fact of territory† (Shaw, 487). Thus, according to Shaw, â€Å"without territory a legal person cannot be a state† (487). Shaw emphasized, â€Å"A state is deemed to exercise exclusive power over its territory† (Shaw, 487). The principle of territorial integrity is the foundation of

Classroom Management Observation Essay Example for Free

Classroom Management Observation Essay Did you view the elementary or secondary video? * Elementary 1. Observation and Description A. Describe the observed classroom routines.The class starts with the children removing materials from their desk to get organized. Having the children remove all materials from their desk to organize them according to size teaches the children to have respect for their property and others. Next, the children go on a classroom tour. She also discusses the procedure for signing books in and out of the classroom library. Next, she describes the procedures for if students want to borrow materials off the teacher’s desk. The students must always ask. Then, the children go over the schedule, so they know, what to expect throughout the school day. After that, the children learn the importance of attending school on a daily basis. Next, the teacher has the students’ line up. The first time students are required to line up; the teacher explains the procedure and the reason. Then the teacher discusses signing in and out procedures for going to the office, the restroom, and the nurse station. The students must sign out, print their name on the appropriate line, and circle the place they are going, then put the time, and take a pass. The students learn that they have more freedom in the third grade than second, because they no longer have to ask to get water at the water fountain and sharpen pencils, as long as there is no one else at the water fountain, or the pencil sharpener. Finally, the students learn the procedures for getting crayons and other materials. The same rules apply as long as no one is at the crayon or material station the students can go ahead and get crayons. The students must grab a basket, grab a handful of crayons for the basket, and go quietly back to their seats. This will decrease classroom interruptions and will gain a sense of trust between the students and the teacher. B. Describe the implementation methods of routines in the ob served classroom. The teacher implements the methods of routines as she would any other subject. For example, if the teacher were teaching math, she would describe it, explain it, and then have the children practice it. In the video, the teacher described to the students how they would line up, then she explained why they would line up that way, and then she let the children practice. 2. Analysis, Exploration and Reasoning A. Predict students’ level of engagement with the observed classroom routines.The students level of engagement is high the children are enthusiastic about learning what the teacher expects of them. Later in the school year, I predict that the student will have the same level of engagement as from the first day of school. The children will know what the teacher expect of them, regarding routines and procedures. The routines and procedures will become more of a habit. B. Analyze a possible purpose for the observed classroom routine. The purpose for the children removing all items from their desk and organizing them according to size is so that the children will know where all books and materials are at all times. This will decrease the amount of classroom disruptions, because the children will not have to go back and forth to their book bags and other areas of the classroom to get materials. The materials are in an organized area in the desk. 3. Connections to other teaching practices A. Explain the purpose of the observed classroom routines as they relate to the learning environment.The purpose of having the children take a classroom tour is to familiarize themselves with centers and materials so the children will know exactly where to go when they need certain things, which will cause less classroom disruptions. The observed routines relates to an improved learning environment for the classroomThe purpose for removing materials from their desk to get organized is to teach students to have respect for their pro perty, themselves, and others. Having respect for their property and others improves the learning environment because each student will strive to act in a respectable manner by having respect for themselves and their surroundings, which in turn, will decrease the amount of classroom disruptions. Next, the children go on a classroom tour. She also discusses the procedure for signing books in and out of the classroom library. Having the students sign books in and out of the classroom library teaches students the importance of returning items back to their correct placement, which relates to improving the learning environment because keeping items neat, organized in their correct placement is essential for a learning environment to thrive. Next, she describes the procedures for if students want to borrow materials off the teacher’s desk. The students must always ask. This teaches the student to never take anything without asking and again to have respect for their property and others, which in turn improves th e learning environment, if everyone ask before taking something of someone else. Next, the teacher has the students’ line up. The first time students are required to line up; the teacher explains the procedure and the reason. The teacher has the student to quie line up quietly, by size to see and account for all students as the students walk through the hall. This improves the learning environment because the teacher is responsible for the whereabouts of all students so seeing each child is important to have a successful learning environment. The students must remain quiet as they walk through the hall so they will not disturb other students. Then the teacher discusses signing in and out procedures for going to the office, the restroom, and the nurse station. Having the students sign in and out teaches how important it is to let the teacher know their whereabouts. This also teaches responsibility. It is crucial for the teacher to know the whereabouts of all students in their class at all times, having the students sign in and out keeps track of all whereabouts and the time, which improves the learning environment. The students learn that they have more freedom in the third grade than second, because they no longer have to ask to get water at the water fountain and sharpen pencils, as long as there is no one else at the water fountain, or the pencil sharpener. This creates a sense of trust between the students and the teacher, which improves behavior because the students will not want to abuse the trust. Gaining trust improves behaviors, and good behaviors improve the learning environment and give students an abundance of opportunities to learn. Finally, the students learn the procedures for getting crayons and other materials. The same rules apply as long as no one is at the crayon or material station the students can go ahead and get crayons. The students must grab a basket, grab a handful of crayons for the basket, and go quietly back to their seats. This will decrease classroom interruptions and will gain a sense of trust between the students and the teacher, which improves the learning environment. Students’ transitions many times throughout out the day, from entering school, to going to breakfast, to leaving the lunchroom, to entering class. Transitions between activities can be challenging and stressful for students, but with organization and key expectations, teachers will eliminate a lot of chaos during these transitions. K–8 Situations 1. Beginning of the day: Class is starting A. enter classroom, the children will find seat B. empty book bag, organize desk C. hangs up book bag, sit quietly wait for instructions to begin tasks 2. End of the day: Going home A. get book bag off hanger place books needed for homework in book bag B. clean up desk and area around desk C. Sit and remain quietly until the teacher calls your way of transportation 3. Transition between activities: Moving to centers A. At the signal (dims the lights) the students to end activity; students begin putting materials away for the current assignment. B. Students clean up and take out materials from next assignment C. when the teacher turns back on the light, students must be in their seat quietly ready to begin next activity. 4. Distribution of materials: Getting crayons off shelf A. makes sure no one is at crayon station B. WALK over to the crayon station, grab a basket, and take a handful of crayons C. return quietly to your desk 5. Field trip: unloading the bus A. get off the bus on the field trip, make sure you are with your partner B. listens to ALL directions C. stay in designated groups 6. Recess: Going to the gym A. Line up quietly for recess B. Walk quietly down the hall to gym or designated area for the day C. Listen for directions for activities for the day 7. Fire or disaster drills: exiting the building in the event of fire A. When the alarm sounds, the students will quickly line up in front of the door B. Listen for the teacher to call your row C. Walk quickly and quietly a line, listen for directions from your teacher What teachers do at the beginning of the school year to organize their rooms and establish a management system influences what happens throughout the rest of the year. Routines are the stamina of daily classroom life. The routines above are vital in order for your class to run smoothly. In the beginning of the day, when class is starting it is important for the children to enter class find their seat, empty book bags and organize their desk quietly so that the teacher can take attendance and notate how many children attended the class that day. At the end of the day, when the children are going home, it is important for the students to get book bag off hanger place books needed for homework in book bag, clean up desk and area around desk, sit, and remain quietly until the teacher calls your way of transportation. This is important so that all students to get home safely on the appropriate way of transportation. When transitioning between activities such as moving to centers, it is appropriate for student to end the current activity quickly to get started with the next. Time management is important throughout the school day since all activities are time-sensitive. When a student needs, materials such as crayons it is appropriate for the students to wait until the teacher call their row before proceeding to the material station. If a student needs crayons individually, then it’s important that the student make sure there is no one else at the station before he or she proceeds to get crayons. By waiting for the teacher to call your row or by making sure no one else is at the crayon station this will ensure the ease of all students getting material because this routine controls traffic flow in the classroom and will decrease classroom disruption. When the children go on a field trip and have to unload the bus it is appropriate for the students to follow all the routines so that the teacher and parent helpers can make sure all students are accounted for and no one is lost. When the children have recess and go to the gym it is appropriate that all students remain quietly and walk in a straight line so hallway traffic is controlled. The children should also remain quiet so they do not disturb other classrooms. Finally, in the event of a fire, it is appropriate that when the alarm sounds, the students will quickly line up in front of the door, listen for the teacher to call your row, walk quickly and quietly a line, listen for directions from your teacher. This will ensure the safety of all teachers and students.

Profile of a Hate Crime Offender Essay example -- Papers

Profile of a Hate Crime Offender Sterilized from emotion, hate crime, also called bias crime, is those offenses motivated in part or singularly by personal prejudice against other because of a diversity-race, sexual orientation, religion, ethnicity/national origin, or disability. Hate crimes are committed out of anger, ignorance, and lack of knowledge of another’s ideas and beliefs. There are many causes for an individual to commit a hate crime. Also, many different profiles fit the description of a hate crime offender. There are ways to prevent and control hate crimes, but they will always be present in society as long as every person has the right to express his or her opinion. The term hate crime first appeared in the late 1980’s as a way of understanding a racial incident in the Howard Beach section of New York City, in which a black man was killed while attempting to evade a violent mob of white teenagers, shouting racial epithets. Although widely used by the federal government of the United States, the media, and researchers in the field, the term is somewhat misleading because it suggests incorrectly that hatred is invariably a distinguishing characteristic of this type of crime. While it is true that many hate crimes involve intense animosity toward the victim, many others do not. Conversely, many crimes involving hatred between the offender and the victim are not ‘hate crimes’ in the sense intended here. For example an assault that arises out of a dispute between two white, male co-workers who compete for a promotion might involve intense hatred, even though it is not based on any racial or religious differences... ...Violence on College Campuses," (Baltimore: National Institute Against Prejudice and Violence, 1990). Fox, James and Jack Levin Overkill: Mass Murder and Serial Killing Exposed (New York: Dell, 1996). Freeman, Steven, "Hate Crime Laws: Punishment Which Fits the Crime," Annual Survey of American Law (New York: New York University School of Law, 1993); pp. 581-585. Hamm, Mark S. Hate Crime: International Perspectives on Causes and Control (Anderson: Cincinnati, 1994). Jacobs, James B. and Jessica S. Henry, "The Social Construction of a Hate Crime Epidemic," The Journal of Criminal Law and Criminology (Winter 1996); 366-391. Jacobs, James B. and Kimberly A. Potter "Hate Crimes: A Critical Perspective," Crime and Justice: A Review of Research, Ed. Michael Tonry (University of Chicago Press: Chicago, 1997).

Control System- Pressure Regulator

A type or certain group of elements that function together as a unified whole, is a system. This widened description thus gives some meaning to control systems as a whole. By re-establishing the basic principles and functions worked out, a system's limit can be extended to include little or more characteristics just as long as each singular variable contributes in a way to the particular system activity. This explains that the system does not halt interaction to other systems or peripherals. In the process industry, the term control system is sometimes normally used to specify a process, and the apparatus basically required to run the process. The system is tested with various actions so it will conform to a standard, these include; load, commands and disturbances which cause it to respond in some individual manner. A system is best made so that it will respond positively. In order for a system to act in the way prescribed is to control the system. The basic concept of comparing the measured and prescribed system performance, and then taking any action to change the process thereby minimizing errors, is called negative feedback. The system can vice-versa be called a closed-loop control system, or a negative feedback control system. To make a system automated it should be mechanized. To create the maintenance of a constant value in a control, is not the major primary objective of control; once the prescribed behavior is achieved, the control function is fulfilled. Although the use of control measure is in most cases involved with mechanical equipment, they can also be used in fields such as (e.g. in the social, biological or in different other systems). The science of achieving control, by using or not using feedback, is the method of control theory. This is applicable to system control in general. Most control systems have evolved by the practice of trial and error, for the critical design of system controls with the need for extensive analysis of two factors, the control devices and the process. 2.0 TYPES OF REGULATORS- 2.1 SIMPLE PRESSURE CONTROL SYSTEM (SELF OPERATED REGULATOR): For a typical uncontrolled system, let us say it is required for it to provide a standard pressure, P, at a given measure and that the discharge, Q2, provides for an external system, which, its need for this fluid varies. At a given time interval, the external system regulates valve No. 2 to comply with the needed specifications. The curves given in Fig 1.0 FIG 1.1 Shows the way in which it alters the process of the pressure. In earlier results in time, t1, some initial stable condition exists where, Q1 and Q 2 are of the same and the process pressure is significantly at the aimed equivalent. A level change occurs at, Q1 when time is at, t1, this reduces the fluid mass between the valves. This is followed mainly by a drop in the process pressure. For a system which is uncontrolled the pressure decline will continue until the drop over valve No. 1 is enough again to build equal flows and a new constant state functioning condition is gained. The procedure can be controlled; i.e. the suitable needed pressure can be managed if the significant rise in Q1 were gotten by increasing the opening of valve No. 1. A typical way of doing this is given in Fig 1.1. FIG 1.3 The response for the process pressure is sent to a spring opposed diaphragm that gives free way for the pressure to manoeuvre the valve. In a working mode, the contraction in the spring will be set so that at some constant state working condition the required process pressure, acting on the diaphragm section, this balances the force that the spring carries. The aimed process pressure is known as a set point. Changes from the set point which is caused by load variation will be controlled because as the process pressure differs, the matching force given back to the diaphragm will regulate the valve position to reduce the pressure variance to a certain range of value around the set point. The careful control of the pressure will rely on how big a flow change the regulator will be able to carry out for a minimal amount of pressure. The regulator flow change to process pressure change is the gain of the regulator and this will rely on the diaphragm area, the valve size, stiffness of the spring, and the general pressure drop over it. The corrective activity done by the regulator is proportional to the change of the process from its set point. Such an element is called the proportional or proportional mode, control. When using the proportional control, the corrective action can only carry on when some different outlines exist. The final pressure change needed to completely stroke the regulator is known as the proportional band and it shows around what limits the regulator can control. FIG 1.4 illustrates where the process measurement supplies the whole valve actuating force, this is known as self-operated regulators. FIG 1.5 The above demonstrates a self operated regulators made for the control of temperature, flow and level. The operation method is practically the same with the pressure regulator. They are widely used in various applications of specialty in the industrial field. 3.0 PILOT OPERATED PRESSURE REGULATOR: This regulator uses a little pilot valve assembly to aide in actuating the main valve. Generally the pilot operated pressure regulator shown in Fig 1.6 FIG 1.6 when in operation, the process pressure works on the lower side of the main diaphragm which is similar to the self operated regulator. The pilot also quantifies the process pressure and, upstream pressure as power source, changes the loading on the top side of the main diaphragm. The diaphragm serves as an amplifier, generally bearing a gain from process to loading pressure of 10 to 20 psi per psi. This is because of both feed back path ways one through the direct one and the other through the pilot, the regulators demonstrate a more complex control action than the simple proportional mode. The pilot operated regulator are available for all the four major process variables; flow, pressure level and temperature even though the direct acting path is left out in some cases. With the pilot operated regulator it is generally easier to achieve a greater regulator gain. Both the self and pilot operated regulators share similar attributes that have, in many cases, brought about some restraints. In some instances like if the fluid is corrosive, loaded with contaminants or of very high temperature, apparent issues may arise. Essentially at most one of the diaphragm casings, should, be able, to hold the maximum process pressure. The most possibly vital deficiency, from, the basis that static and dynamic elements of any specific form of process; i.e., level, pressure, etc. can differ respectively from one installation to the other so the choice of the amount of gain to be designed into a regulator without causing any sort of system instability, is made a very tasking procedure. It means that the regulator can not be altered to suit the characteristics of the process to which it has been applied. This Fig 1.7 is the block diagram of a pilot operated regulator FIG 1.7 3.1 INSTRUMENT CONTROL: The pressure control system illustrated in Fig 1.8 FIG 1.8 it surpasses all the limits considerably attached to the self and pilot operated regulators. It generally contains three detachable hardware pieces: the process controller, the control valve, and the valve actuator. Other controllers such as this stands for one of an entire family of peripherals generally referred to as instruments. The process fluid touches only the control valve and its sensing element. This is a small part which has no orifice and could get contaminated. They can be made from several types of materials to achieve high standard against corrosion and temperature. An external source for pneumatic power is used for working parts in the controller to provide clean, dry instrument air. The air supply is regulated so that the pressure is at a standard rate and that the controller and actuator are made to work with a standard pressure signal level, free of the process fluid pressure. A regular standard pressure supply is within 20 psig with a usual ranging of signal within 2 to 15 psig. They are ready for use with numerous sensing element and they give the significance of the process which is being controlled. They are commonly known as indicative controllers. To minimize trial and error the set point is normally calibrated to generally prevent subsequent start ups. The Fig 1.8 is like most pneumatic controller models, it has two levels with an adjustable measure of response and amplification around both levels. The input variable moves an end of a beam which holds the air flow through a nozzle. The pressure of the nozzle is sensitive to the point of the beam itself. The pressure of the nozzle performs on the top diaphragm of a pressure equal valve assembly that is the second amplifier level. As a result of the huge valve ports it is has the capacity to give an extreme flow progression to the actuator which works as a power amplifier. The pressure is given back to the amplifiers which moves the nozzle beams in a direction which opposes the sensing effect. Element motion ( i.e. negative feedback ). The three way valve behaves as a pressure divider and its regulation decides what amount of feedback should be consumed. Leaving the dynamics out, the controller can be seen as having a high gain movement path with a regulated gain response path. It provides only proportional control mode but its area of reach can be freely adjusted over a vast range by means of the pressure divider. The purpose of the integral mode is to remove any steady state process deviation and the reason for the deviation mode is to give an improved transient control. These modes improve the flexibility of the controller. 4.0 COMPUTER CONTROL- The reason for central control is to bring to a particular location, adequate information and hardware to allow an operator to control the plant variances, which are product yield and quality, and to manage the automated control of process variances, which are flow and temperature. In order for all duties to be carried out by the operator must have a sound knowledge of process variances, but how they should be. The adequate values for the process variances will differ as operating circumstances may be affected by things such as contamination, variations in reactants, load, changes in the products wanted or quality. The set points calculation can be made from the plant requirements and information about the plant operating elements. The early use of digital computers for process controls was for plant performance calculation the whole system works in an automated form sampling of transmitter signals. The optimizing of control and direct digital controls in Fig 1.9 FIG 1.9 Illustration of the hierarchy control as given in FIG 2.0 LLOYD, SHELSON, G AND ANDERSON, GERALD, D. 1971. Industrial Control Process. An Introduction to Hardware .1st edn. Marshaltown, Iowa: Fisher Controls Co. pp. 83-92. 5.0 CONTROL ELEMENTS- 5.1 BASIC ELEMENT: Any system can be broken down into various divisions for understanding it's rather important to consider two levels of dub divisions. The first are those components in a control loop that are manufactured, tested, purchased and even design as standalone pieces of equipments. 5.2 MATHEMATICAL MODELS OF PHYSICAL DEVICES: The mathematical representation of physical devices can be done with the use of the fundamental physical laws which include Ohm's Law Newton's Laws, flow equations, conservation of mass and energy, etc. The use of impedance is often but not always helpful when deriving a mathematical model when a system is dynamic there is a circumstance which is forcing the change. This force is always some kind of potential energy .When a change occurs that is the dynamic system which is a movement known as flux. This flux generally depends on the physical characteristics of the system. Some forms of flux are shown in Table 1.0. TABLE 1.0 Impedance shows the mathematical relationship between potential and flux, it is the ratio of an increase change in potential to an increase change in flux. EQUATION. 1 LLOYD, SHELSON, G AND ANDERSON, GERALD, D. 1971. Industrial Control Process. Basic Elements.1st edn. Marshaltown, Iowa: Fisher Controls Co. pp. 93-94. 6.0 PROCESS CONTROL SYSTEM The performance of a process control system is calculated by considering the system's output to the set point. The difference between both amounts is error or system deviation .The response of a regulatory system, for a step increase in load. Many standard words are defined in the schematic and several of them are used to describe the mistakes which might occur. It is obvious that no certain way such as settling time, maximum value of transient deviation, steady- state deviation gives a measure of system performance. Different approaches methods have been used for the error index. A tank which has several sources of flow as given in Fig 2.1 can be easily described by using block diagrams and flow components. For easy understanding lets say Pc = constant. The equation for flow is: PRESSURE PROCESS STEADY FLOW (FIG 2.1) In order to illustrate the nature of a process control system consider Fig 2.2 for the control equipment has a valve, diaphragm, actuator, and a locally mounted PI measuring controller FIG 2.2 LLOYD, SHELSON, G AND ANDERSON, GERALD, D. 1971. Industrial Control Process. Process Dynamics .1st edn. Marshaltown, Iowa: Fisher Controls Co. pp. 202-204. 7.0 ACCURACY AND SENSITIVITY 7.1 ACCURACY â€Å"In general, the greatest accuracy-closest regulation-is obtained with the largest diaphragm and shortest range which will give the required control pressure. For example, a control pressure of 40 psig can be obtained with any of the three ranges in model RP-1065-A and with two of the three ranges in model RP-1066-A. Closest regulation can be expected with the 5 – 50 psi range of model RP-1066-A (size 10 diaphragm). See table for â€Å"Accuracy of Regulation.† Unbalanced port areas are not considered in the values tabulated. Small amounts of unbalance are present in single-seated 1/2†³ â€Å"A† valves and in semi-balanced double seated valves 2†³ through 4†³. Under conditions of high pressure drop, the forces opposing valve closure will influence selection of the regulator model (diaphragm size). See â€Å"Accuracy of Regulation† tabulation for actual port area unbalance† FIG 2.3 [WWW] http://www.skilenvironmental.com/documents/160_RP1065A_1066A.pdf In addition what changes can made to the diaphragm area, spring rate, orifice size, and inlet pressure, the regulator accuracy can be enhanced by simply putting a pitot tube. Internal to the regulator, the pitot tube joins the diaphragm cover with a low-pressure, high velocity region inside the regulator body. The pressure in the area will be lower than P2 when it goes downstream. By using a pitot tube to calculate the lower pressure, the regulator change in its response to any change in P2. The pitot tube tricks the regulator. 7.2 SENSITIVITY The principle of operation and loading, actuating, and control components are in all designs. Many regulators use simple wire coil springs to control the downstream pressure. Numerous size springs are used to allow regulation of the secondary pressure around a target range. The needed pressure is at the centre one-third of the rated outlet pressure range. In the lower end of the pressure range, the spring loses some sensitivity; at the high end, the spring close to it maximum capacity. Regulators can use diaphragm or piston to detect or sense downstream pressure. Diaphragms are more sensitive to pressure variations and react quicker. They can operate where sensitive pressure settings are needed (lower than 0.04 psi). Pistons generally are more rugged and give a larger effective sensing area in a particular size regulator. The functional difference between general-purpose and precision regulators is the degree of control accuracy of the output pressure. Output pressure accuracy is gotten by the droop due to flow changes (regulator characteristics). [WWW] http://machinedesign.com/article/pneumatic-pressure-regulators-1115 8.0 FEEDBACK This section will develop the performance limitations imposed by a particular load when a conventional flow control valve is utilized in the valve-actuator component. It will then show that the load versus flow characteristic of the forward loop can be modified very advantageously. Various techniques utilized in the past for this purpose, such as controlled actuator by-pass leakage and structural feedback, are compared with a new technique called dynamic pressure feedback (D.P.F.). The analytical work is fortified by reports of actual tests of a representative system. The electrohydraulic position servo can be represented by the block diagram shown in Fig 2.4. This diagram separates the valve-actuator integration from the hydraulic and structural compliance of the actuator. The diagram also represents the particular load case under discussion. The analysis of servo stability and performance is affected by the choice of position feedback location. Output position can be measured at the actuator or at the load. If the feedback is from the actuator position, the analytical task is made more difficult. However, it is apparent from the block diagram that the quantities Xp and X0 react in a proportional manner to inertia forces. It is reasonable to conclude, therefore, that the two cases should yield similar results. This discussion will be based on selection of feedback intelligence from the load position, X0, due to the relative simplicity of analysis. However, a careful comparison of this simpler case with the more difficult to analyse case of actuator feedback position has been carried out. An analogue computer was utilized for this comparison. The results of the study confirmed that the two cases are really very similar in dynamic performance achievable. The use of actuator position feedback suffers some comparative penalty statically with respect to error introduced by external (load disturbance) forces.† [WWW] http://www.emeraldinsight.com/Insight/ViewContentServlet;jsessionid=6464D27CC3E73FAFE7C6220F352B4F85?contentType=Article&Filename=/published/emeraldfulltextarticle/pdf/1270320604.pdf FIG 2.4 [WWW]http://www.emeraldinsight.com/Insight/ViewContentServlet;jsessionid=6464D27CC3E73FAFE7C6220F352B4F85?contentType=Article&Filename=/published/emeraldfulltextarticle/pdf/1270320604.pdf 9.0 PRESSURE MEASUREMENT â€Å"Fluid pressure can be defined as the measure of force per-unit-area exerted by a fluid, acting perpendicularly to any surface it contacts (a fluid can be either a gas or a liquid, fluid and liquid are not synonymous). The standard SI unit for pressure measurement is the Pascal (Pa) which is equivalent to one Newton per square meter (N/m2) or the KiloPascal (kPa) where 1 kPa = 1000 Pa. In the English system, pressure is usually expressed in pounds per square inch (psi). Pressure can be expressed in many different units including in terms of a height of a column of liquid. CONVERSION UNITS FOR COMMON UNITS OF PRESSURE (TABLE 2) PRESSURE TERMS RELATIONSHIP (FIG 2.5) Table lists commonly used units of pressure measurement and the conversion between the units. Pressure measurements can be divided into three different categories: absolute pressure, gage pressure and differential pressure. Absolute pressure refers to the absolute value of the force per-unit-area exerted on a surface by a fluid. Therefore the absolute pressure is the difference between the pressure at a given point in a fluid and the absolute zero of pressure or a perfect vacuum. Gage pressure is the measurement of the difference between the absolute pressure and the local atmospheric pressure. Local atmospheric pressure can vary depending on ambient temperature, altitude and local weather conditions. The U.S. standard atmospheric pressure at sea level and 59à ¯Ã‚ ¿Ã‚ ½F (20à ¯Ã‚ ¿Ã‚ ½C) is 14.696 pounds per square inch absolute (psia) or 101.325 kPa absolute (abs). When referring to pressure measurement, it is critical to specify what reference the pressure is related to. In the English system of units, measurement relating the pressure to a reference is accomplished by specifying pressure in terms of pounds per square inch absolute (psia) or pounds per square inch gage (psig). For other units of measure it is important to specify gage or absolute. The abbreviation .abs' refers to an absolute measurement. A gage pressure by convention is always positive. A .negative' gage pressure is defined as vacuum. Vacuum is the measurement of the amount by which the local atmospheric pressure exceeds the absolute pressure. A perfect vacuum is zero absolute pressure. Fig 2.5 shows the relationship between absolute, gage pressure and vacuum. Differential pressure is simply the measurement of one unknown pressure with reference to another unknown pressure. The pressure measured is the difference between the two unknown pressures. This type of pressure measurement is commonly used to measure the pressure drop in a fluid system. Since a differential pressure is a measure of one pressure referenced to another, it is not necessary to specify a pressure reference. For the English system of units this could simply be psi and for the SI system it could be kPa. In addition to the three types of pressure measurement, there are different types of fluid systems and fluid pressures. There are two types of fluid systems; static systems and dynamic systems. As the names imply, a static system is one in which the fluid is at rest and a dynamic system is on in which the fluid is moving†. [WWW] http://www.scribd.com/doc/2339144/Understanding-Pressure-and-Pressure-Measurement 10.0 CONTROLLERS The major use of controllers is to detect errors in the variables and to create error correction messages that which is caused by the error. To complete this task the controller design must have an adjustable set point that can be comparison to the process variable. The error that is given is sent as a response for needed action to be carried out. The block diagram is given in Fig . The input could be as an input from the transmitter, which happens in the situation involving a receiver-controller. A three mode controller transfer function likely should be as given in the equation , the static gain has been resolved in two perspectives ; K is the nominal output and input spans and this would normally n=be unity for a receiver controller, and Kc is an adjustable measurement known as proportional gain. EQUATION. 2 The three modes stated above give the derivative, integral, and proportional modes respectively. FIG 2.6 Simpler controller designs employing one or two modes are often used. The basic combinations are P- Proportional only I- Integral only PI- proportional plus integral PD proportional plus derivative PID proportional plus integral plus derivative The transfer function may be derived from EQUATION. 2 by eliminating the appropriate terms. In the self operated regulator the actuator, controller and sensor are normally the same thing and with the same element. The controller has no other than the set point and has fixed gain and practically no adjustments. The transfer function is taken as: EQUATION. 3 Considering an example with a regulator with a set point of 5 psig and a flow capacity of 0.6, a temperature of 60 degree (Fahrenheit) and a pressure of 5 psig. The off set flow capacity will be 20 percent. The density can be determined with the use of the equation of state of a perfect gas as shown below: CALCULATION .1 LLOYD, SHELSON, G AND ANDERSON, GERALD, D. 1971. Industrial Control Process. Control Components .1st edn. Marshaltown, Iowa: Fisher Controls Co. pp. 115 – 148. 11.0 INPUT AND OUTPUT â€Å"This simple valve model has three states: OPEN, WORKING, and CLOSED. As the valve is the only component of the pressure-regulator that has state, the composite device, likewise, has only three states: [OPEN], [WORKING], and [CLOSED]. Suppose the input pressure is decreasing and the pressure-regulator is in state [WORKING], then dXFp = +, which causes A, the cross-sectional area available for flow to increase. This raises the possibility that A