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Private branch exchange system - Free Essay Example
Sample details Pages: 31 Words: 9234 Downloads: 6 Date added: 2017/06/26 Category Statistics Essay Did you like this example? INTRODUCTION 1.0 INTRODUCTION Private branch exchange system (PBXs) operates as a connection within private organizations usually a business. Because they incorporate telephones, the general term extension is used to refer to any end point on the branch. The PBX handles calls between these extensions. Don’t waste time! Our writers will create an original "Private branch exchange system" essay for you Create order The primary advantage of PBXs was cost savings on internal phone calls: handling the circuit switching locally reduced charges for local phone services. The private branch exchange (PBX) provides internal station-to-station communications for a well-defined set of users. Three distinct generations of private branch exchanges have appeared. In the first generation (1900-1930), a human operator manually set up calls. Second-generation private branch exchanges (mid-1930s to mid-1970s) used mechanical relays to establish the call path. The third generation of private branch exchanges is the stored-program microprocessor-controlled system. Introduced in the mid-1970s, these systems use computer instructions to perform the call set-up and tear-down. The third-generation private branch exchange is physically much smaller than electromechanical models, uses less power, and generates less heat.(Brooks, 1999) In this project, the design of a 4 line telephone systems with full signaling and switching functions similar to those of the central office systems was embarked upon. Dial tone, busy tone, and ring tone are provided during call process. Switching employs integrated circuit (IC) matrix switches on four buses. Thus, this system is expandable to 8 lines (4 pairs) if more hardware is added. This system is switching on the Dual Tone Multi Frequency (DTMF) dialing signal. 1.1 STATEMENT OF PROBLEM The major problems this project intends to deal with are: * Cut down cost of internal calls made within a company. * Eliminate the need for a central telephone company to help you monitor your internal calls. * Eliminate Stress of notification of telephone company each time you need a new extension and thereby reducing cost. * Ensure security of your internal calls which otherwise can be tapped by company operating it. * Eliminate the need for a manual switchboard and subsequently an operator to connect the calls. * Reduce man-hours lost through staff walking about in an office in order to pass information to each other. 1.2 AIMS AND OBJECTIVES: The main aim of this project is to design and implement a 4 line private exchange box that is able to create connection between four different telephone lines internally without having to connect to an external or trunk line. The objectives include: * Establishing connections between the telephone sets of any two users. (e.g. mapping a dialed number to a physical phone) * Maintaining such connections as long as the users require them. (i.e. channeling voice signals between the users) * Creating an easy means of communication in an office without getting to spend money for their internal calls. * To switch between telephone users thereby creating connections. * To make sure the connection remains in place as long as it last, by keeping its resources. * To properly end the connection when a user hangs up. 1.3 SIGNIFICANCE OF STUDY The ability or concept of providing an easy and less expensive way of communication within a small office or organization without having to pay for your internal calls or having limits to the rate or length of calls within the office. Also it is not necessary to go from office to office when something is needed, information is to be passed; a call to a colleague saves stress of walking about. 1.4 SCOPE OF STUDY The Private Exchange System in this project is limited to a four lines which means that internal calls can be made from only four nodes. As such, it is only suitable for very small organization. 1.5 RESEARCH METHODOLOGY The review of existing and related works to source appropriate information on how to go about the implementation of the project will be carried out. Information shall be gathered from text books, magazines, journals, and World Wide Web to provide answers in relation to the study. Based on the review, the design and implementation of a four line private exchange box system shall be carried out. 1.6 LIMITATIONS OF STUDY There are several factors that could contribute to the group not delving deeper into this project which could have resulted in a more comprehensive work. Constraints are unavoidable in any system, be it a natural system or a computer system. Due to the extensiveness of this project topic, limitations were encountered some of which include: * Time constraint. * Financial constraints. * Inadequate facilities to work with. 1.7 ORGANIZATION OF WORK In chapter one, the research topic is introduced, which is followed by the statement of problem after which the aims and objectives of the study are stated, significance of study, scope of study and research methodology are all identified. The second chapter gives us a view of the related works which have been done and how they are related to our work. The third chapter is about our design methodology and this emphasizes on how the whole private exchange system works and its components. The quality of the system is tested and documented in chapter four. Also in chapter four, an in-depth manual of the system functions and contents is given. A summary of all chapters, a conclusion is outlined in chapter five. CHAPTER TWO LITERATURE REVIEW 2.0 HISTORY OF PRIVATE EXCHANGE BOX In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls. A central office is the physical building used to house inside plant equipment including telephone switches, which make phone calls work in the sense of making connections and relaying the speech information. Early telephone exchanges are a suitable example of circuit switching; the subscriber would ask the operator to connect to another subscriber, whether on the same exchange or via an inter-exchange link and another operator. In any case, the end result was a physical electrical connection between the two subscribers telephones for the duration of the call. The copper wire used for the connection could not be used to carry other calls at the same time, even if the subscribers were in fact not talking and the line was silent. The first telephone exchange opened in New Haven, Connecticut in 1878. The switchboard was built from carriage bolts, handles from tea pot lids and bustle wire and could handle two simultaneous conversations. Later exchanges consisted of one to several hundred plug boards staffed by telephone operators. Each operator sat in front of a vertical panel containing banks of  ¼-inch tip-ring-sleeve (3-conductor) jacks, each of which was the local termination of a subscribers telephone line. In front of the jack panel lay a horizontal panel containing two rows of patch cords, each pair connected to a cord circuit. When a calling party lifted the receiver, a signal lamp near the jack would light. The operator would plug one of the cords (the answering cord) into the subscribers jack and switch her headset into the circuit to ask, number please? Depending upon the answer, the operator might plug the other cord of the pair (the ringing cord) into the called partys local jack and start t he ringing cycle, or plug into a trunk circuit to start what might be a long distance call handled by subsequent operators in another bank of boards or in another building miles away. 2.1 PBX SYSTEM COMPONENTS PBX is a telephone exchange serving a single organization and having no means for connecting to a public telephone system it serves a user company which wants to have its own communication branch to save some money on internal calls. This is done by having the exchanging or switching of circuits done locally, inside the company. There are some important components which play a major role in the implementation of an effective PBX system. Some of the Component * The PBXs internal switching network. * Central processor unit (CPU) or computer inside the system, including memory. * Logic cards, switching and control cards, power cards and related devices that facilitate PBX operation. * Stations or telephone sets, sometimes called lines. * Outside Telco trunks that deliver signals to (and carry them from) the PBX. * Console or switchboard allows the operator to control incoming calls. * Uninterruptible Power Supply (UPS) consisting of sensors, power switches and batteries. * Interconnecting wiring. * Cabinets, closets, vaults and other housings. 2.2 PRIVATE BRANCH EXCHANGE (PBX) There are essentially three different types of PBXs that could be deployed within an organization infrastructure. It is necessary to be certain of type in use, so as to be able to identify the essential numbers. There are currently three different PBX classes: Centrex; Direct Inward Dialing (DID)/Direct Outward Dialing (DOD) and Megalink. 2.2.1 CENTREX Centrex is the easiest of the PBX types. This PBX, unlike other types is installed within the telephone companys Central Office (CO) and does not require dialing an extension code (normally 4 numeric characters) after having dialed the 7 to 10 digit number to connect a call to an individual. In a simplistic manner, it could be considered similar to the telephone used at home. It has an area code (NPA), an Exchange (NXX) and a Unique Number, (0000 to 9999) and does not require the dialling of another number after it in order to place a call. These numbers may be entered through a PAD. 2.2.2 Direct Inward Dialing(DID)/ Direct Outward Dialing (DOD) Unlike a Centrex, these types of PBXs is not installed within the telephone companys Central Office. Secondly, if a cut of the telephone wire occurs outside the building, individuals are still able to dial within it to talk to colleagues by simply dialing their extension number (normally a number between 0000 to 9999) lastly; this PBX is controlled via a computer interface at a control console. Since the PBX requires constant power to function, it may be necessary to hook it with generating plant, in the absence of power from electricity company. Direct Inward Dialing (DID) and Direct Outward Dialing (DOD) are simply features of an Automated PBX which require that you dial the companys general telephone number followed by the entry of the individuals extension number when prompted to do so. DIDs allow you direct dialing (seven digits) to locate an individual within an organizations PBX. It is a trunk phone number that must be entered into the PAD program and flagged as a PBX to ensure that the outgoing line(s) get priority. PBXs may be privately owned or telecommunication company owned. If PBX is programmable it is possible to assign specific trunk lines to specific numbers. These trunk line numbers may then be entered on PAD thus providing dial tone protection. 2.2.3 MEGALINKS The major difference between this and a Centrex PBX is that the exiting trunk lines from a building to the telephone company central office are comprised of fibre optic cables and not through twisted pair wiring. Another difference is that unlike a Centrex that is identified by its ten digit telephone number (NPA, NXX, and Unique), Megalinks are identified by a circuit ID number. This number may contain characters and may even resemble a telephone number, however, PAD does not allow for the entry of the circuit switch identifier. The reason is quite simple, fibre optic cabling circuits can handle far more traffic than twisted pair PBXs. 2.3 INTERFACE STANDARDS Interfaces for connecting extensions to a PBX include: à ¢Ã¢â€š ¬Ã‚ ¢ POTS (Plain Old Telephone System) the common two-wire interface used in most homes. This is cheap and effective, and allows almost any standard phone to be used as an extension. à ¢Ã¢â€š ¬Ã‚ ¢ Proprietary the manufacturer has defined a protocol. One can only connect the manufacturers sets to their PBX, but the benefit is more visible information displayed and/or specific function buttons. à ¢Ã¢â€š ¬Ã‚ ¢ DECT a standard for connecting cordless phones. à ¢Ã¢â€š ¬Ã‚ ¢ Internet Protocol For example, H.323 and SIP. Interfaces for connecting PBXs to each other include: à ¢Ã¢â€š ¬Ã‚ ¢ Proprietary protocols if equipment from several manufacturers is on site, the use of a standard protocol is required. à ¢Ã¢â€š ¬Ã‚ ¢ QSIG for connecting PBXs to each other, usually runs over T1 (T-carrier) or E1 (E-carrier) physical circuits. à ¢Ã¢â€š ¬Ã‚ ¢ DPNSS for connecting PBXs to trunk lines. Standardised by British Telecom, this usually runs over E1 (E-carrier) physical circuits. à ¢Ã¢â€š ¬Ã‚ ¢ Internet Protocol H.323, SIP and IAX protocols are IP based solutions which can handle voice and multimedia (e.g. video) calls. Interfaces for connecting PBXs to trunk lines include: à ¢Ã¢â€š ¬Ã‚ ¢ Standard POTS (Plain Old Telephone System) lines the common two-wire interface used in most domestic homes. This is adequate only for smaller systems, and can suffer from not being able to detect incoming calls when trying to make an outbound call. à ¢Ã¢â€š ¬Ã‚ ¢ ISDN the most common digital standard for fixed telephony devices. This can be supplied in either Basic (2 circuit capacity) or Primary (24 or 30 circuit capacity) versions. Most medium to large companies would use Primary ISDN circuits carried on T1 or E1 physical connections. à ¢Ã¢â€š ¬Ã‚ ¢ RBS (Robbed bit signaling) delivers 24 digital circuits over a four-wire (T1) interface. à ¢Ã¢â€š ¬Ã‚ ¢ Internet Protocol H.323, SIP, MGCP, and Inter-Asterisk eXchange protocols operate over IP and are supported by some network providers. Interfaces for collecting data from the PBX: à ¢Ã¢â€š ¬Ã‚ ¢ Serial interface historically used to print every call record to a serial printer. Now an application connects via serial cable to this port. à ¢Ã¢â€š ¬Ã‚ ¢ Network Port (Listen mode) where an external application connects to the TCP or UDP port. The PBX then starts streaming information down to the application. à ¢Ã¢â€š ¬Ã‚ ¢ Network Port (Server mode) The PBX connects to another application or buffer. à ¢Ã¢â€š ¬Ã‚ ¢ File The PBX generates a file containing the call records from the PBX. The call records from the PBX are called SMDR, CDR, or CIL. (Micheal, 1999) 2.4 TELEPHONE Telephone is one of the most amazing devices ever created. Although most people take it completely for granted, the telephone is one of the most amazing devices ever created. To talk to someone, just pick up the phone and dial a few digits; connection will be established with the person and a two-way conversation can take place. It is an instrument designed for simultaneous transmission and reception of the human voice. It works by converting the sound waves of the human voice to pulses of electrical current, transmitting the current, and then retranslating the current back to sound. The U.S. patent granted to Alexander Graham Bell in 1876 for developing a device to transmit speech sounds over electric wires is often called the most valuable ever issued. Within 20 years, the telephone acquired a form that has remained fundamentally unchanged for more than a century. The advent of the transistor (1947) led to lightweight, compact circuitry . Advances in electronics have allo wed the introduction of a number of smart features such as automatic redialing, caller identification, call waiting, and call forwarding. The figure 2.1 shows the major components that makes up a telephone set. 2.5 HOW TELEPHONE WORKS When a person speaks into a telephone, the sound waves created by his voice enter the mouthpiece. An electric current carries the sound to the telephone of the person he is talking to. A telephone has two main parts: (1) the transmitter and (2) the receiver.The Transmitter of a telephone serves as a sensitive electric ear. It lies behind the mouthpiece of the phone. Like the human ear, the transmitter has 14 eardrum. The eardrum of the telephone is a thin, round metal disk called a diaphragm. When a person talks into the telephone, the sound waves strike the diaphragm and make it vibrate. The diaphragm vibrates at various speeds, depending on the variations in air pressure caused by the varying tones of the speakers voice. Behind the diaphragm lies a small cup filled with tiny grains of carbon. The diaphragm presses against these carbon grains. Low voltage electric current travels through the grains. This current comes from batteries at the telephone company. The pressure on the carbon grains varies as sound waves make the diaphragm vibrate. A loud sound causes the sound waves to push hard on the diaphragm. In turn, the diaphragm presses the grains tightly together. This action makes it easier for the electric current to travel through, and a large amount of electricity flows through the grains. When the sound is soft, the sound waves push lightly on the diaphragm. In turn, the diaphragm puts only a light pressure on the carbon grains. The grains are pressed together loosely. This makes it harder for the electric current to pass through them, and less current flows through the grains. Thus, the pattern of the sound waves determines the pressure on the diaphragm. This pressure, in turn, regulates the pressure on the carbon grains. The crowded or loose grains cause the electric current to become stronger or weaker. The current copies the pattern of the sound waves and travels over a telephone wire to the receiver of another telephone. The Receiver serves as an electric mouth. Like a human voice, it has vocal cords. The vocal cords of the receiver are a diaphragm. Two magnets located at the edge of the diaphragm cause it to vibrate. One of the magnets is a permanent magnet that constantly holds the diaphragm close to it. The other magnet is an electromagnet. It consists of a piece of iron with a coil of wire wound around it. When an electric current passes through the coil, the iron core becomes magnetized. The diaphragm is pulled toward the iron core and away from the permanent magnet. The pull of the electromagnet varies between strong and weak, depending on the variations in the current. Thus, the electromagnet controls the vibrations of the diaphragm in the receiver.The electric current passing through the electromagnet becomes stronger or weaker according to the loud or soft sounds. This action causes the diaphragm to vibrate according to the speakers speech pattern. As the diaphragm moves in and out, it pulls and pushes the air in front of it. The pressure on the air sets up sound waves that are the same as the ones sent into the transmitter. The sound waves strike the ear of the listener and he hears the words of the speaker. (www.howstuffworks.com) 2.6 THE RINGER Simply speaking this is a device that alerts you to an incoming call. It may be a bell, light, or warbling tone.  The ringing signal is in an AC wave form. Although the common frequency used can be any frequency between 15 and 68 Hz. Most of the world uses frequencies between 20 and 40 Hz.  The voltage at the subscribers end depends upon loop length and number of ringers attached to the line; it could be between 40 and 150 Volts. The ringing cadence (the timing of ringing to pause), varies from company to company. In the United States the cadence is normally 2 seconds of ringing to 4 seconds of pause. An unanswered phone in the United States will keep ringing until the caller hangs up. But in some countries, the ringing will time out if the call is not answered. The most common ringing device is the gong ringer; a solenoid coil with a clapper that strikes either a single or double bell. A gong ringer is the loudest signaling device that is solely phone-line powered. Modern telephones tend to use warbling ringers, which are usually ICs powered by the rectified ringing signal. The audio transducer is a small loudspeaker via a transformer. Ringers are isolated from the DC of the phone line by a capacitor. Gong ringers in the United States use a 0.47 uF capacitor. Warbling ringers in the United States generally use a 1.0 uF capacitor. Telephone companies in other parts of the world use capacitors between 0.2 and 2.0 uF.  The  paper capacitors of the past have been replaced almost exclusively with capacitors made of Mylar film. Their voltage rating is always 50 Volts. The capacitor and ringer coil, or Zeners in a warbling ringer, constitute a resonant circuit. When phone is hung up (on hook) the ringer is across the line; and it has merely silenced the transducer, not removed the circuit from the line. When the telephone company uses the ringer to test the line, it sends a low-voltage, low frequency signal down the line (usually 2 Volts at 10 Hz) to test for continuity. The company compares result with the expected signals of the line. This is how it can tell whether an added equipment is on the line. If your telephone has had its ringer disconnected, the telephone company cannot detect its presence on the line. Because there is only a certain amount of current available to drive ringers, if ringers are added to phone lines indiscriminately, a point will be reached at which either all ringers will cease to ring, some will cease to ring, or some ringers will ring weakly. A normal ringer is defined as a standard gong ringer as supplied in a phone company standard desk telephone; Value given to this ringer is Ringer Equivalence Number (REN) 1. It can be as high as 3.2, which means that device consumes the equivalent power of 3.2 standard ringers, or 0.0, which means it consumes no current when subjected to a ringing signal. If there is a problem with ringing, it could be that the REN is greater than 5, disconnecting ringers until REN is at 5 or below will usually solve the problem. Other countries have various ways of expressing REN, and some systems will handle no more than three of their standard ringers. But whatever the system, if an extra equipment was added and the phones stop ringing, or the phone answering machine wont pick up calls, the solution is disconnect ringers until the problem is resolved. Warbling ringers tend to draw less current than gong ringers, so changing from gong ringers to warbling ringers may help spread the sound better. Frequency response is the second criterion by which a ringer is described. Because a ringer is supposed to respond to AC waveforms, it will tend to respond to transients (such as switching transients) when the phone is hung up, or when the rotary dial is used on an extension phone. This is called bell tap in the United States; in other countries, its often called bell tinkle.  While European and Asian phones tend to bell tap, or tinkle, United States ringers that bell tap are considered defective. The bell tap is designed out of gong ringers and fine tuned with bias springs.  Warbling ringers for use in the United States are designed not to respond to short transients; this is usually accomplished by rectifying the AC and filtering it before it powers the IC, then not switching on the output stage unless the voltage lasts long enough to charge a second capacitor.(Roberts, 2006) 2.7 HOOK SWITCH This is a lever that is depressed when the handset is resting in its cradle. It is a two-wire to four-wire converter that provides conversion between the four-wire handset and the two-wire local loop. There are two stages, which are off hook and on hook Off hook: The state of a telephone line that allows dialing and transmission but prohibits incoming calls from being answered. The phone is off-hook when the handset is removed from the base unit of a stationary phone or press Talk on a portable phone. The term stems from the days when the handset was lifted off an actual hook. When the handset was removed, a spring caused contacts to press together, closing the circuit from the telephone to the switchboard. On hook: The condition that exists when a telephone or other user instrument is not in use, i.e., when idle waiting for a call. Note: on-hook originally referred to the storage of an idle telephone reciever, i.e., separate earpiec, on a swithch hook. The weigth of the recieved depresses the sping leaded switch hook thereby disconnecting the idle instrument (except its bell) from the telephone line.    (Roberts, 2006) 2.8 THE DIAL There are two types of dials in use around the world. The most common one is called pulse, loop disconnect, or rotary; the oldest form of dialing, its been in use since the 1920s. The other dialing method, is called Touch-tone, Dual Tone Multi-Frequency (DTMF) Pulse dialing is traditionally accomplished with a rotary dial, which is a speed governed wheel with a cam that opens and closes a switch in series with the phone and the line. It works by actually disconnecting or hanging up the telephone at specific intervals. The United States standard is one disconnect per  digit,  so if a 1, is dailled, the telephone is disconnected once. To dial a seven means that it will be disconnected seven times; and dialling a zero means that it will hang up ten times. Some countries invert the system so 1 causes ten disconnects and 0, one disconnect. Some add a digit so that dialing a 5 would cause six disconnects and 0, eleven disconnects. There are even some systems in which dialing 0 results in one disconnect, and all other digits are plus one, making a 5 cause six disconnects and 9, ten disconnects. Although most exchanges are quite happy with rates of 6 to 15 Pulses Per Second (PPS), the phone company accepted standard is 8 to 10 PPS. Some modern digital exchanges, free of the mechanical inertia problems of older systems, will accept a PPS rate as high as 20. Besides the PPS rate, the dialing pulses have a make/break ratio, usually described as a percentage, but sometimes as a straight ratio. The North American standard is 60/40 percent; most of Europe accepts a standard of 63/37 percent. This is the pulse measured at the telephone, not at the exchange, where its somewhat different, having traveled through the phone line with its distributed resistance, capacitance, and inductance.  In practice, theÂà ‚ make/break ratio does not seem to affect the performance of the dial when attached to a normal loop. However,each pulse is a switch connect and disconnect across a complex impedance, so the switching transient often reaches 300 Volts. Usually, a safe practice is not to have fingers across the line when dialing. Most pulse dialing phones produced today use a CMOS IC and a keyboard. Instead of pushing finger round in circles, then removing finger and waiting for the dial to return before dialing the next digit, the button can be punched as fast as desired. The IC stores the number and pulses out the number at the correct rate with the correct make/break ratio and the switching is done with a high-voltage switching transistor. Because the IC has already stored the dialed number in order to pulse it out at the correct rate, its a simple matter for telephone designers to keep the memory alive and allow the telephone to store, recall, and redial the Last Number Dialed (LND). This feature enables easy redial by picking up the handset and pushing just one button. Touch tone is the most modern form of dialing. It is fast and less prone to error than pulse dialing. Compared to pulse, its major advantage is that its audio band signals can travel down phone lines further than pulse, which can travel only as far as the local exchange. Touch-tone can therefore send signals around the world via the telephone lines, and can be used to control phone answering machines and computers. Bell Labs developed DTMF in order to have a dialing system that could travel across microwave links and work rapidly with computer controlled exchanges. Each transmitted digit consists of two separate audio tones that are mixed together. The four vertical columns on the keypad are known as the high group and the four horizontal rows as the low group; the digit 8 is composed of 1336 Hz and 852 Hz. The level of each tone is within 3 dB of the other. A complete touch-tone pad has 16 digits, as opposed to ten on a pulse dial. Besides the numerals 0 to 9, a DTMF dial has *, #, A, B, C, and D. Although the letters are not normally found on consumer telephones, the IC in the phone is capable of generating them. The * sign is usually called star or asterisk.  The # sign, often referred to as the pound sign. is actually called an octothorpe. Although many phone users have never used these digits - they are not, after all, ordinarily used in dialing phone numbers. They are used for control purposes, phone answering machines, bringing up remote bases, electronic banking, and repeater control. The one use of the octothorpe that may be familiar occurs in dialing international calls from phones. After dialing the complete number, dialing the octothorpe lets the exchange know youve finished dialing.  It can now begin routing your call; without the octothorpe, it would wait and time out before switching your call. Standard DTMF dials will produce a tone as long as a key is depressed.  No matter how long you press, the tone will be decoded as the appropriate digit. The shortest duration in which a digit can be sent and decoded is about 100 milliseconds (ms). Its pretty difficult to dial by hand at such a speed, but automatic dialers can do it. A twelve-digit long distance number can be dialed by an automatic dialer in a little more than a second about as long as it takes a pulse dial to send a single 0 digit.(Roberts,2006) 2.9 MODULAR CONNECTORS Modular connector is the name given to a family of electrical connectors that were originally used in telephone wiring. Even though they are still used for that purpose they are used for a variety of other things as well. A modular connectors advantage over many other kinds include; small size and ease of plugging and unplugging. Many uses that originally used a bulkier connector have migrated to modular connectors. Probably the most well known applications of modular connectors is for telephone jacks and for ethernet jacks, which are nearly always modular connectors. Figure 2.2 shows types of connectors commonly used. Modular connectors were first used in the registered jack system, so registered Jack specifications describe them precisely. These are the specifications to which all practical modular connectors are built. Modular connectors come in four sizes: 4-, 6-, 8-, and 10-position. A position is a place that can hold a conductor (pin). The positions need not all be used; a connector can have any even number of conductors. Unused positions are usually the outermost positions. The connectors are designed so that a plug can fit into any jack that has at least the number of positions as the plug. Where the jack has more positions than the plug, the outermost positions are unused. However, plugs from different manufacturers may not have this compatibility, and some manufacturers of eight position jacks now explicitly warn that they are not designed to accept smaller plugs without damage. The positions of a jack are numbered left to right, looking into the receiving side of the jack with the hook (locking tab or clip) side down, starting at 1. The positions of plug are numbered the same as the jack positions with which they mate. The number of a conductor is the same as the number of the position its in. So for example in a 6P2C plug, only conductors 3 and 4 exist. Some connector types in the family are indexed, which means their shape is altered from the standard somewhat to prevent them from mating with standard connectors. The indexing is usually a different shape or position of the hook, but can also be an additional tab. The members of the family are typically identified using the format [number]P[number]C, e.g. 6P2C, which means 6 positions, 2 conductors. Alternate formats [number]x[number] (e.g. 62) or [number]/[number (e.g. 6/2) are also used. Modular connectors have gender. The male connector is called a plug, while the female connector is called a jack or sometimes a socket. The application of jack versus plug is generally based on physical installation only. Jacks go in walls and panels, while plugs go on wires. Modular connectors also go by the names modular phone jack/plug, RJ connector, and Western jack/plug. The 8P8C modular connector type is often called RJ45, Modular connectors lock together. A spring-loaded tab called a hook on the plug snaps into a jack so that the plug cannot be pulled out. To remove the plug, the hook has to be pressed. The most common way to install a jack in a wall or panel is with the hook side down. This usually makes it easier to operate the hook when removing the plug, because the person grabs the plug with thumb on top and presses the hook with the index finger. A disadvantage of modular connectors is that the fragile hook on a plug easily snags and often breaks while trying to pull a c ord through other cords or other obstructions. Some higher quality cables have a flexible sleeve called a boot over the plug, or a special hook design, to prevent this. Boots are seen mainly on 8P8C data cables.(www.whatis.com) CHAPTER THREE DESIGN METHODOLOGY 3.0 OVERVIEW This chapter emphasizes on the information or content presented, the functions that will be performed and the behaviour that each system component is expected to exhibit. The design focuses on how the system looks like, the layout and technical structure of the system. A breakdown of this system circuits will further ascertain the functionality of the system. The figure below is a block diagram that describes the whole communication system. The block diagram in figure 3.0 is comprised: * THE CONTROL UNIT * TONE GENERATION * DECODING AND SWITCHING 3.1 THE CONTROL CIRCUIT This is where all control functions of the system are being carried out. The main device that performs this role is the microcontroller which is the heart of the system. The frequency used to generate the tones is from the microcontroller, It is used to monitor the hook comparator to know when it is off-hook (the condition that exists when a telephone is in use) or on-hook (the condition that exists when a telephone is not in use) .When a number is dialed the microcontroller helps to check the EPROM (Erasable Programmable Read Only Memory) if the number dialed is valid before it allows a call to be successful. A microcontroller is a computer-on-a-chip used to control interfaces needed for a simple application. A microcontroller is a single integrated circuit, commonly with the following features: * bit processors to sophisticated 32- or 64-bit processors * serial ports * signal conversion circuits. * RAM for data storage * program storage The 8051 used in this project is an 8-bit microprocessor originally designed in the 1980s by Intel that has gained great popularity since its introduction. Its standard form includes several standard on-chip peripherals, including timers, counters, plus 4kbytes of on-chip program memory and 128 bytes of data memory, making single-chip implementations possible. The 8051 memory architecture includes 128 bytes of data memory that are accessible directly by its instructions. A 32-byte segment of this 128 byte memory block is bit addressable by a subset of the 8051 instructions, namely the bit-instructions. External memory of up to 64 Kbytes is accessible by a special instruction. Up to 4 Kbytes of program instructions can be stored in the internal memory of the 8051, or the 8051 can be configured to use up to 64 Kbytes of external program memory .The majority of the 8051s instructions are executed within 12 clock cycles. The package outline of 8051 microcontroller is shown in fig 3.1 (William, 1998) 3.1.1 EPROM (Erasable Programmable Read Only Memory) The function of the EPROM is to store the program that was used .The numbers assigned to each telephone are being programmed into it. It is a type of computer memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages than those normally used in electronic circuits. Once programmed, the EPROM can be erased only by exposing it to strong ultraviolet light. It is a ROM-type chip that can hold data from 10-20 years. It is different from PROM because it can be programmed more than once. The EPROM is configured or reconfigured using an EPROM programmer. The EPROM has 8 data lines (bits AD0 AD7) forming a byte wide data bus. Enabling both ALE (Address latch Enable) and PSEN (Program Store Enable) causes all the bits to appear on the data lines, as such individual bits cannot be enabled. The byte of data appears on these lines as 0s or 1s. The data lines of the EPROM are bi-directional, they are outputs when it is being read and they serve as inputs are programming it. Figure 3.2 shows the package view of EPROM (Erasable Programmable Read Only Memory).(Mano, 2008) A latch is a kind of bistable multivibrator, an electronic circuit which has two stable states and thereby can store one bit of information its output may depend not only on its current input, but also on its previous inputs.The Latch also separates the Intel 8051 microcontroller address lines from its data lines. The Intel 8255 Programmable Peripheral Interface chip is a peripheral chip. This chip is used to give the CPU access to programmable parallel I/O. The 8255 chip is used together with a microcontroller to expand its I/O capabilities. 3.2 TONE GENERATION The tone generation deals with how the tones used for the exchange box are generated. The sine wave is the most familiar AC waveform and is the type of wave used in telecommunication. It derives its name from the fact that the current or voltage varies with the sine of the elapsed time. The sine wave is unique in that it represents energy entirely concentrated at a single frequency. However, the microcontroller only generates a square wave. A square wave is a waveform that is built up from a series of harmonics derived from the fundamental frequency. A true square wave will have 3rd, 5th, 7th, 9th, 11th, 13th and 15th harmonics. The rise and fall is very abrupt, straight up and straight down. For an audio signal, all of these combined odd order harmonics would not be considered to be a pleasant sound. Hence, to generate the required sine wave, the square wave has to be filtered. 3.2.1 LOW-PASS FILTER CIRCUIT The low-pass filter circuit is used to cut-off the harmonics in the square waves in order to convert it to a sine wave which is needed. The term low-pass filter merely refers to the shape of the filters response. A low-pass filter is a filter that passes low-frequency signals but attenuates (reduces the amplitude of) signals with frequencies higher than the cutoff frequency. The actual amount of attenuation for each frequency varies from filter to filter. It is sometimes called a high-cut filter, or treble cut filter when used in audio applications. The concept of a low-pass filter exists in many different forms, including electronic circuits. One simple electric circuit that will serve as a low-pass filter consists of a resistor in series with a load, and a capacitor in parallel with the load as shown in figure 3.4. The capacitor exhibits reactance, and blocks high-frequency signals, causing them to go through the load instead. At higher frequencies the reactance drops, and the capa citor effectively functions as a short circuit. The combination of resistance and capacitance gives you the time constant of the filter t = RC .The break frequency, also called the turnover frequency or cutoff frequency (in hertz), is determined by the time constant. The figure below is a low pass filter circuit.    (www.answers.com) 3.2.2 BUFFER The buffer is used to separate the phase of low-pass filter circuit so that it does not affect other operations on the circuit. A buffer amplifier is one that provides electrical impedance transformation from one circuit to another. Typically a buffer amplifier is used to transfer a voltage from a first circuit, having a high output impedance level, to a second circuit with a low input impedance level. The interposed buffer amplifier prevents the second circuit from loading the first circuit unacceptably and interfering with its desired operation. If the voltage is transferred unchanged (the voltage gain is 1), the amplifier is a unity gain buffer; also known as a voltage follower.                                                                                                                                                                                                                              Âà ‚            3.2.3 PASSIVE COMPONENTS Some Passive components were utilized in the design. Passive components are electronic component that does not increase the power of the electrical signal on which it acts. It may actually end up decreasing the power of the signal it is acting upon. As such, a passive component may draw the energy it uses for its own operation directly from the signal on which it is operating. They are constant components and have resistance (R), capacitance (C) and inductance (L) properties respectively. Resistors: increase the current at the expense of the voltage. A resistors resistance (R) is a measure of the ratio of its potential difference (V) with the current (I): R = V / I The value of resistors are usually expressed in Ohms (?), Capacitors: store electrical energy. A capacitors capacitance (C) is a measure of the amount of charge (Q) stored on each plate for a given potential difference or voltage (V) which appears between the plates. C = Q / V In SI units, a capacitor has a capacitance of one farad when one coulomb of charge is stored due to one volt applied potential difference across the plates. Since the farad is a very large unit, values of capacitors are usually expressed in microfarads ( µF), nanofarads (nF) or picofarad (pF) Their schematic diagrams and symbols are shown in figure 3.5 below. 3.2.4 TRANSFORMER A transformer is being used in the circuit used to generate a ring back tone because the voltage required to generate it is 90v 120v and the voltage in the circuit is 5v 12v. So the transformer was used to step up the voltage. A transformer is a device that transfers circuit to another through wires. A changing current in the first circuit (the primary) creates a changing magnetic field; in turn, this magnetic field induces a changing voltage in the second circuit (the secondary). By adding a load to the secondary circuit, one can make current flow in the transformer, thus transferring energy from one circuit to the other. The secondary induced voltage VS is scaled from the primary VP by a factor ideally equal to the ratio of the number of turns of wire in their respective windings.    (James, 2004)                                                             Four different tones can be obtained from the circuit of figure 3.6 The square waves from the microcontroller are being passed to a low pass filter circuit and are converted to sine waves. The sign waves are then buffered. A buffer is used to separate the phase of low-pass filter circuit so that it does not affect other operations on the circuit. Two of the frequencies are then mixed to generate a tone. Dial tone: it is a telephony signal used to indicate that the telephone exchange is working and ready to accept a call. The tone stops when the first numeral is dialed, or if there is no response after going off-hook. The tone is generated by adding two sine waves of 350Hz and 440Hz Ring back tone: this is a tone that is heard when your call is successful. The tone is generated by adding two sine waves of 440Hz and 480Hz. Busy tone: is a telephony signal used to indicate that the called telephone is being used at the moment, so it cannot accept a call. The tone is generated by adding two sine waves of 480Hz and 620Hz. Ring tone: is generated when a call goes through to the other partys phone. The tone is composed of a sine wave of 20Hz. The voltage required is 90V 120V, thus necessitating the use of step-up transformer. 3.3 DECODING AND SWITCHING This is where the decoding of the tones and the switching of the phone lines are carried out. The switching is performed by use of a relay is used in the phone circuit because of the voltage of the ring back tone which uses 90V 120V while the system uses 5V 12V. The relay is used to switch between the ring back tone and the normal phone circuit. Therefore each time a call is made and it gives a ring back tone the relay switches to ring back and when the call is picked it goes back to the normal circuit. The relay is an electromechanical switch operated by a flow of electricity in one circuit and controlling the flow of electricity in another circuit. The relay consists basically of an electromagnet with a soft iron bar, called an armature, held close to it. A movable contact is connected to the armature in such a way that the contact is held in its normal position by a spring. When the electromagnet is energized, it exerts a force on the armature that overcomes the pull of the spring and moves the contact so as to either complete or break a circuit. When the electromagnet is de-energized, the contact returns to its original position. Variations on this mechanism are possible: some relays have multiple contacts; some are encapsulated; some have built-in circuits that delay contact closure after actuation; some, as in early telephone circuits, advance through a series of positions step by step as they are energized and de-energized. They are used in a wide variety of applications throughout industry, such as in telephone exchanges, digital computers. 3.3.1 COMPARATOR The comparator is used to detect when the phone is off hook or on hook. The microcontroller is being used to monitor the comparator, once it is off-hook current flows through and it detects it. In electronics a comparator is a device which compares two voltages or currents and switches its output to indicate which is larger. A dedicated voltage comparator will also contain additional feature such as an accurate, internal voltage reference.. In theory the reference and input voltages can be anywhere between zero and the supply voltage but there are practical limitations on the actual range depending on the particular device used(www.wikipedia.com) 3.3.2 DTMF (DUAL-TONE MULTI FREQUENCY) DTMF GENERATOR AND DECODER (MT8870): DTMF (Dual-tone Multi Frequency) is a tone composed of two sine waves of given frequencies. Individual frequencies are chosen so that it is quite easy to design frequency filters, and so that they can easily pass through telephone lines (where the maximum guaranteed bandwidth extends from about 300 Hz to 3.5 kHz). The dial tone heard when the phone set is picked up is called Dual Tone Multi-Frequency (DTMF). The name was given because the tone that we heard over the phone is actually made up of two distinct frequency tones, hence the name dual tone. The DTMF tone is a form of one way communication between the dialer and the telephone exchange. A complete communication consists of the tone generator and the tone decoder. In this project MT8870 was used as the main component to decode the input dial tone to 4 digital output. The MT8870 is a complete DTMF receiver integrating both the bandsplit filter and digital decoder functions. The filter sectio n uses switched capacitor techniques for high and low group filters; the decoder uses digital counting techniques to detect and decode all 16 DTMF tone-pairs into a 4-bit code. The tones are generated from phones based on the keys pressed. This table resembles a matrix keyboard. The X and Y coordinates of each code give the two frequencies that the code is composed of. Notice that there are 16 codes; however, common DTMF dialers use only 12 of them. The A through D are system codes. Most end users wont need any of those (are used by some PBX systems for special functions).  It uses electronics and computer to assist in the phone line connection. Basically on the caller side, it is a dial tone generator. When a key is being pressed on the matrix keypad, it generate a unique tone consisting of two audible tone frequency. For example, if the key 1 is being press on the phone, the tone you hear is actually consist of a 697hz 1209hz sine signal. Pressing key 9 will generate the tone form by 852hz 1477hz. The frequency use in the dial tone system is of audible range suitable for transmission over the telephone cable. On the telephone exchange s ide, it has a decoder circuit to decode the tone to digital code. For example, the tone of 941hz + 1336hz will be decoded as binary 1010 as the output. This digital output will be read in by a computer, which will then act as a operator to connect the callers telephone line to the designated phone line. The telephone exchange will generate a high voltage signal to the receiving telephone, so as to ring the telephone bell, to notify the receiving user that there is an incoming call. (Stephen, 1997). 3.3.3  74393 DUAL 4-BIT (0-15) RIPPLE COUNTER We are using this ripple counter to clock the microcontroller also it is used for the DTMF (Dual Tone Multi Frequency). It used as a replica counter for the DTMF decoder in order to double check the binary bits that have been decoded by the DTMF. The 74393 contains two separate 4-bit (0 to 15) counters, one on each side of the chip, they are ripple counters. The count advances as the clock input becomes low (on the falling-edge), this is indicated by the bar over the clock label. This is the usual clock behavior of ripple counters and it means a counter output can directly drive the clock input of the next counter in a chain. For normal operation the reset input should be low, making it high resets the counter to zero (0000, QA-QD low). The figure below is a 74393 clock. 3.3.4    8 1 LINE ANALOG SWITCH A multiplexer selects one of several input signals and passes it on to the output. It is a circuit that accepts several inputs and selects one of them at any given time to pass on to the output. The routing of the desired data input to the output is controlled by select inputs often referred to as Address inputs). The analog switch is used to switch between the four phone lines and also the dial tone, busy tone, ring back tone.` (Tocci, 2004) CHAPTER FOUR IMPLEMENTATION AND TESTING 4.0 INTRODUCTION The physical realization of this project is very important, because the designer will see the result of his work. The working ability of this project was constructed to meet the desired specifications, and that is in a nutshell, a system that is capable of controlling communication between four telephone lines. This switching system is a four line private exchange box. In this chapter, the workability and efficiency of the private exchange box system, after its various subsystems have been combined together and examined. 4.1 IMPLEMENTATION AND TESTING To test this project, at least two (2) touch tone telephone lines will be needed. The first phone A is connected to the private exchange box and the second phone B also to be connected to the exchange box. When the phone A is picked up, the microcontroller detects that the phone has been picked which will then make the hook comparator know that it is off hook. It then sends a control signal to the The 8-1 line analog switch and it switches to dial tone. When phone A recieves a dial tone, it means it is ready to make a call. When phone A makes a call by dialing the number assigned to phone B, the DTMF(Dual tone multi-frequency) Decoder decodes the number into four binary bits one by one and temporarily stores them in the RAM (random access memory) of the microcontroller till it matches with one of the numbers stored in the EPROM, the microcontroller checks the hook comparator of phone B if it off-hook or on-hook. If phone B is on-hook it sends a control signal to the 8-1 line analog switch via the processor to switch to ring back tone therefore the relay has to switch to the ring generator and disconnect from the normal circuit because the ring genera tor uses 90V while the normal circuit uses 5V- 12V. Phone B will then ring and when the phone is picked you are able to communicate with each other . If the microcontroller detects that the phone is off-hook, it sends a control signal to the 8-1 line analog switch and it switches to busy tone. That means the phone B is in use so you cannot talk to that person at that time you have to call back later. 4.2 OBSERVATIONS The project is working as expected. Calls can be made from any of the phones and the ring tone, busy tone and dial tone is heard. Calls can be made simultaneously and you can hear the voice of the person talking clearly. There is no limit to the time at which you can talk. CHAPTER FIVE RECOMMENDATION AND CONCLUSION 5.0 INTRODUCTIONThis chapter gives a summary of all the chapters in this project, a conclusion and also recommends where the system can be used. 5.1 SUMMARY Chapter one talks about the introduction of the project and its layout. In Chapter two we talked about the history of the project, the system components, reviewed other works that have been carried out relating to our project, how telephones work. The Third chapter analyzes the components that make up the system and how they relate to each other in order to make the system function. Chapter four explains how the system works during testing and how it is expected to function.  5.2 RECOMMENDATION The execution of this project has left possibilities for improvement which could not be carried out during the design and implementation because of the limited time and resources. The possible improvement on this project is that the amount of phones used can be increased and you can have one of the phone lines connected to an external line for trunk calls.This project is recommended for use in offices, at home, hospitals or hotels For full implementation in a bigger area you can increase the number of telephone lines in the system so that more people can have access to each other. 5.3 CONCLUSION The beauty of this project is the fact that a means of communication that is cheap, efficient, secure and technology driven has been designed. The Four Line Telephone Exchange Box is a device that enhances the internal communication within an office or home. The idea of Communication is reliability, security, efficiency, connectivity and cost. This Project has put all this into consideration, and has come out with a very efficient way of communicating in perhaps an Organization, offices and even for our Case Study Babcock University. Bibliography Bigelow, Stephen (1997). Understanding Telephone Electronics. New York, Newness Calvert, J. B (2003).Basic Telephones and Switchboard. London, Pitman. Harlow, James (2004). Electric Power Transformer Engineering. New Jersey. CRC Press. Brooks, John (1995). The First Hundred Years of Telephone. New York: Harper and Row. Huurdeman, Anton A. (2003). The Worldwide History of Telecommunications, IEEE Press and J. Wiley Sons. New York. M. Morris Mano and Charles R. Kime (2008). Logic and Computer Design Fundamentals, Prentice Hall, Inc. Milton Mueller (1989). Technology and Culture, Vol. 30. Virginia, Pitman. Myer, Ralph O (1995). Old Time Telephones: Technology, Restoration and Repair. New York, Tab Books. Noll A. Michael (1999). Introduction to Telephones and Telephone Systems. Norwood, Mass. Artech House. Payne, William (1998). Embedded Controller Forth for the 8051 Family, London, Macmillan Press Ronald J. Tocci, Neal S.Widner Gregory L. Moss (2004). Digital systems principles and applications, pp 525-531 .New Jersey, Prentice Hall. Steve Roberts (2006). Telephone Installation Handbook . Exeter, Pergammon. www.howstuffworks.com www.privateline.com www.whatis.comwww.answers.com www.wikipedia.com
Friday, December 20, 2019
The Crucible By Arthur Miller - 1670 Words
A prominent and influential twentieth century American playwright from Harlem, New York, Arthur Miller was a dramatist whose works are focused on human purpose. Some of his most famous works include Death of a Salesman, All My Sons, and The Crucible. Miller s play, The Crucible, is based in the Puritan town of Salem, Massachusetts. Throughout Salem in the spring of 1692, a wave of hysteria, fear, and panic fell on the settlers of the town caused by an increase in the belief of witches in the village. The tension of the situation increases when Reverend Parris catches his niece and the former servant of John Proctor, Abigail Williams, dancing and singing naked in the forest with about ten other girls from the village. Parris now suspects Abigail is a witch and attempts to get to the bottom of what was going on in the woods that fateful night by inviting Reverend Hale, a famous exorcist in the region, to help out. The appearance of Hale sets off a chain reaction in Salem which ev entually results in the trials and hangings of many people who are falsely accused in the village. Throughout the entire process of these trials, many of the characters under go changes caused by the heat and pressure of the situation brought about by the mass fear of witchcraft in the village. John Proctor constantly changes as the play progresses moving from a guilt-ridden, independent farmer, to a person completely open to confessing his sin, and finally to a defiant man who has greatShow MoreRelatedThe Crucible By Arthur Miller1269 Words  | 6 PagesAt first glance, the playwright Arthur Miller in The Crucible highlights the historical significance of the Salem Witch Trials of 1692, but in fact it is an allegorical expression of his perception of McCarthyism. If the reader has some background information on Arthur Miller’s victimization as a communist, it is evident that the play is a didactic vessel illustrating the flaws of the court system in the 1950’s. The communist allegations were launched at government employees, entertainers and writersRead MoreThe Crucible By Arthur Miller1681 Words  | 7 Pagesof their way to the last dying breath to make sure they leave with a good or bad reputation. In one of the recent literature study in class â€Å"The Crucible†by Arthur Miller, Miller uses characterization to illustrate reputation throughout the play. â€Å"The Crucible†takes place in Salem, Massachusetts. It is based upon the Salem witch trails. In â€Å"The Crucible†, we journey through the life of three characters who reputations plays a major role in the play. The three characters are John Proctor, AbigailRead MoreThe Crucible By Arthur Miller1333 Words  | 6 PagesAs the various characters in The Crucible by Arthur Miller interact, the dominant theme of the consequences of women’s nonconformity begins to slide out from behind the curtains of the play. Such a theme reveals the gripping fear tha t inundated the Puritans during the seventeenth century. This fear led to the famous witch-hunts that primarily terrorized women who deviated from the Puritan vision of absolute obedience and orthodoxy. Arthur Miller presents his interpretation of the suffering by subtlyRead MoreThe Crucible By Arthur Miller998 Words  | 4 Pagesmotivated by jealousy and spite. The Crucible is a four-act dramatic play production that was first performed on January 22, 1953. Arthur Miller used dialogue within the characters to cover the multiple themes; conflicts and resolutions, plus the few directions for the different actions of the play. The Salem Witch Trials were intended to be performed as the play however, when read, it can be more carefully examined and broken down to analyze the techniques. Miller, the playwright, uses literaryRead MoreThe Crucible By Arthur Miller1145 Words  | 5 PagesUnbalance Through The Centuries In Arthur Miller’s play, The Crucible, the author reflects the persecution of communists in America in the 1950’s through a recount of the Salem witch trials. It is often presumed that Miller based his drama directly off of events that were particularly prevalent in the years surrounding the publication of The Crucible- which was released in the year 1953, towards the conclusion of the Korean War. Although there was not a literal witch hunt occurring during this timeRead MoreThe Crucible By Arthur Miller1063 Words  | 5 PagesIn the English dictionary, there are three definitions of the word crucible. One is a metal container in which metals are mixed and melted. Another is a severe test. But the third definition, and the one that I think fits the best for this book, is a place or situation in which different elements interact to create something new. In my mind, this fits because all of the characters had their little grudges and dirty secrets. But when all th ose seemingly little things interact, they formed somethingRead MoreThe Crucible By Arthur Miller1285 Words  | 6 Pages Rationale, Morality, Stereotypes, Pressure, Self-Censorship, Unanimity, and Mindguards. Groupthink has also taken place in our history a a country. The play, The Crucible by Arthur Miller is about a the real-life Salem Witch Trials that happened in 1692 - 1693, in Salem, Massachusetts. Some symptoms of Groupthink found in the Crucible are Rationale, Pressure, and Self-Censorship. The Groupthink symptom, Rationale, is described as when victims of Groupthink ignore warnings: they also collectivelyRead MoreThe Crucible By Arthur Miller811 Words  | 4 Pages While The Crucible, by Arthur Miller, is only a four act play, it still resembles the format of a five act play. The five-act structure evolved from a three-act structure, which was made famous by Roman Aelius Donatus. Donatus came up with three types of plays: Protasis, Epitasis, and Catastrophe. The five-act structure helped to expand the three act structure, mainly made famous by Shakespeare through his many tragedies. Even though The Crucible contains only four acts, it still has the commonRead MoreThe Crucible By Arthur Miller1052 Words  | 5 PagesBuddy Al-Aydi Ms.Healy English 9 CP 14th October 2014 The Crucible Essay The Crucible was a novel written by Arthur Miller in the 1950’s. It was written in a format of the play, portraying an allegory of the Salem Witch-Hunts led by Senator Joseph McCarthy. The book is known to have a inexplicable plot. This plot is advanced by multiple characters in the book in order to ensure that the reader maintains interest with the material that is being read. The farmer, John Proctor, would be theRead MoreThe Crucible By Arthur Miller841 Words  | 4 PagesThe Crucible is a chaotic play, throughout this American classic Arthur Miller takes the reader through multiple events of terror and insanity. While creating a great on-stage play, Arthur Miller portrays his life through the events, the characters, and plot of The Crucible. Using vivid imagery and comprehensible symbolism, Miller manipulates the real personalities of the characters and events in 1600 Salem, Massachusetts to create a symbolic autobiography. Throughout this play, the reader experie nces
Thursday, December 12, 2019
Macbeth vs. a Simple Plan free essay sample
Macbeth, a play written by William Shakespeare in the early 17th century and A Simple Plan, a 1998 Hollywood production are surprisingly similar. These two tragedies illustrate two contented ordinary men, whose lives are irrevocably altered for the worse, resulting in their downfalls. Both men are happily married to women who share their ambitions and become their driving force. Lady Macbeth and Sarah Mitchell are both intelligent and powerful characters as they understand their husbands’ weaknesses and know how to use it to their advantages. Although the men are the ones who act upon the evil plots, the wives play the more important role as the authority and motivation of their actions. Both Lady Macbeth and Sarah formulate plans to obtain their objectives before their husbands can think far enough ahead. The instant Lady Macbeth reads Macbeth’s letter, stating that he met witches who predicted he would be king, she immediately decides that the king will be killed: â€Å"The Raven himself is hoarse / That croaks the fatal entrance of Duncan / Under my battlements†(Macbeth 1. We will write a custom essay sample on Macbeth vs. a Simple Plan or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page 5. 38-40). As Macbeth earlier asks the stars to hide his desire, she openly asks the spirits to strengthen her desire by filling her with manly cruelty: Come, you spirits That tend on mortal thoughts, unsex me here And fill me from the crown to the toe top-full Of the direst cruelty. (1. 5. 40-43) She is clearly willing to do whatever is necessary to seize the throne. When Macbeth arrives home and tells her that King Duncan will come to their castle that night, she says to him: You shall put This night’s great business into my despatch; Which shall to all our nights and days to come Give solely sovereign sway and masterdom. (1. 5. 67-70) This speech shows that Lady Macbeth is the brain behind Macbeth’s actions and that her ambition is strong enough to drive her husband forward. She even facilitates the night’s events as she plans the agenda of the evening, preparing â€Å"wine and wassail†for the two chamberlains, and placing the dagger for Macbeth in the most convenient place. Throughout the play, Lady Macbeth’s shifting control over her husband is mainly responsible for aggravating the struggle between Macbeth’s moralities and â€Å"vaulting ambition†. While Lady Macbeth is integral to her husband’s first crime her power wanes as he begins to act alone. Sarah, on the other hand, is more firm and determined. She ruthlessly attempts to plan out all of Hank’s actions, focusing on what she wants at the expense of others. Just like Lady Macbeth, the moment she realizes the possibility of more wealth and the lifestyle it will bring, she starts to plot her way to obtain it. The night Hank finds the money, Sarah concocts a plan to put five hundred thousand back in the plane to put Hank beyond suspicion, warning him to be extremely careful, while he is still contemplating his guilt. Right after she gives birth to her first child, she announces her second plan, which involves Hank and his brother Jacob blackmailing the third accomplice, Lou. This scene shares some similarity with Lady Macbeth’s own planning for her husband’s cover up of the initial crime. In both instances, the women reveal they are the crucial elements of evil in the actions. Sarah’s second plan leads to more deaths because she does not consider the fact that people react violently when they are threatened. Her determination does not waver as she plans another scheme to avoid the FBI’s investigation for the safety of the money and Hank’s life. Unlike, Lady Macbeth, Sarah’s power of persuasion increases as the story unfolds. Although, it seems like their husbands do all the evil acts, Macbeth and Hank can still be sympathized with because the women proved themselves as the real villain. As a way of setting their plan to action, Lady Macbeth and Sarah manipulated their husbands leaving them with no reason not to obey. Lady Macbeth takes advantage of the fact that she understands Macbeth’s weak spot. Art though afread To be the same in thine own act and valour, As thou art in desire? Wouldst thou have that Which thou esteem’st the ornament of life, And live a coward in thine own esteem, Letting â€Å"I dare not†wait upon â€Å"I would,†Like the poor cat i’ the adage? (1. 7. 39-44) She taunts his fear and tells him to be a man. When Macbeth shows guilt and frailty after killing Duncan, her reply is again filled with manipulation attacking Macbeth’s manhood. She says he is a coward for being afraid of the dead, as they are just like paintings. Also she says that the blood on their hands will be easily washed off by water, even though at the end of the play just before she commits suicide, she constantly obsesses with the imaginary blood that cannot be washed from her hands. When Macbeth experiences hallucinations of Banquo’s ghost, this was her reply: O! these flaws and starts, (Impostors to true fear) would well become A woman’s story at a winter’s fire, Authorized by her grandam. Shame itself! Why do you make such faces? When all’s done, You look but on a stool. (3. 4. 63-68) Although, words like these can snap Macbeth back to his senses, she does not realize that they can also stimulate a man to neglect real consequences and conscience. Ultimately, her words unleash Macbeth’s true evil side. Sarah also exploits Hank’s manhood in the sense that a man’s entire obligation is to provide for and protect his family. When Hank has had enough of the violence and wants to return the money and live life like it used to be, Sarah goads him into keeping it. She says that they would have the same boring jobs for the next thirty years. Their daughter, Amanda would wear second-hand clothes and play with used toys. Jacob would go back to the welfare office but with Lou gone, just himself and his dog in his filthy apartment, he would probably commit suicide. Just like Lady Macbeth, Sarah knows exactly where to hurt Hank. Her words seem to suggest that if Hank returns the money, he would be a very selfish man. She disregards the fact that keeping the money is illegal, and that it has caused many deaths just because she does not want to a simple life, even though they were happy before the possibility of wealth existed. According to the women, if the men back out and show fear, they are not worthy of men but if they carry out the crimes then they are brave and honourable; in reality, it is the other way around, that it takes real courage to resist the temptation of cheating their way into power. As it seems, without the women’s artful schemes that introduce the men to such desperate violence, the men would be incapable of carrying out the crimes themselves. It is doubtful that Macbeth could killed King Duncan and in such a brutal way, without his wife. Although it is Lady Macbeth that keeps him sane for a while and slaps him out of hallucinations, her manipulation gives him the stimulation he needs to commit more violence later on. Moreover, Sarah is the main cause of all the crimes Hank commits. Without her unnecessary plans and her manipulating words, they would have a higher chance of keeping the money safe. They are all so wrapped up in this greedy world; they fail to consider the consequences of their actions more realistically.
Wednesday, December 4, 2019
After Einstein Scientific Genius is extinct
Question: We tend to presume that the scientists of today are somehow more intelligent than those before. But is that true? Is any scientist today more intellegent than a Copernicus or Galileo?! or Newton!? Answer: No, it is not true that the modern society has more intelligent scientists than Copernicus or Newton. Scientists such as Einstein has given the world something new created from scratch with their surprising ideas (Shea, 2016). They have solved fundamental problems like the energy-matter relationship, planetary movements. The new advancements in the present century are the mere extension of pre-existing theories. No scientist in this century has produced entirely new domain such as "Telescopic Astronomy" by Galileo (Simonton, 2013). References Shea, W. R. (2016). Early Modern (Seventeenth and Eighteenth Centuries) Lawrence Lipking. What Galileo Saw: Imagining the Scientific Revolution. xvi+ 314 pp., illus., bibl., apps., index. Ithaca, NY/London: Cornell University Press, 2014. $35 (cloth).History of Science,107(1). Simonton, D. K. (2013). After Einstein: scientific genius is extinct.Nature,493(7434), 602-602.
Thursday, November 28, 2019
King Lear Vision Essays - King Lear, Edmund, Cordelia, Goneril, Lear
King Lear Vision In Shakespeare's tragedy, King Lear, a prominent reoccuring theme is vision and it's relovence. The characters, Lear and Gloucester are Shakespeare's principal means of portraying this theme. Although Lear can physically see, he is blind in the sense that he lacks insight, understanding, and direction. In contrast, Gloucester becomes physically blind but gains the type of vision that Lear lacks. It is evident from these two characters that clear vision is not derived solely from physical sight. Lear's failure to understand this is the principal cause of his demise, while Gloucester learns to achieve clear vision, and avoids a fate similar to Lear's. Throughout most of the play, Lear's vision is clouded by his lack of insight. Since he cannot see into other people's personalities, he can never identify them for who they truly are. When Lear is angered by Cordelia, Kent tries to reason with Lear, who is too stubborn to remain open-minded. Lear responds to Kent's opposition with, "Out of my sight!" to which Kent responds, "See better, Lear, and let me still remain" (I.i.160). Here, Lear is saying he never wants to see Kent again, but he could never truly see him for who he was. Kent was only trying to do what was best for Lear, but Lear could not see that. Kent's vision is not clouded, as is Lear's, and he knows that he can remain near Lear as long as he hides behind his mask. Lear's visual perception is so superficial that the merely the garments and simple disguise that Kent wears easily dupe him. Lear cannot really see Kent. He only learns of Kent's noble and honest character just prior to his death, when his vision is cleared. By this time, however, it is too late for an honest relationship to be saved. Lear's vision is also worsened by his lack of direction in life, and his poor foresight, his inability to predict the consequences of his actions. He cannot look far enough into the future to see the consequences of his actions. This, in addition to his lack of insight into other people, condemns his relationship with his most beloved daughter, Cordelia. When Lear asks his daughters who loves him most, he already thinks that Cordelia has the most love for him. However, when Cordelia says, "I love your Majesty/According to my bond, no more nor less" (I.i.94-95), Lear cannot see what these words really mean. Goneril and Regan are only putting on an act. They do not truly love Lear as much as they should. When Cordelia says these words, she has seen her sisters' facades, and she does not want to associate her true love with their false love. Lear, however, is fooled by Goneril and Regan into thinking that they love him, while Cordelia does not. Kent, who has sufficient insight, is able to see through the dialogue and knows that Cordelia is the only daughter who actually loves Lear. He tries to convince Lear of this, saying, "Answer my life my judgment, / Thy youngest daughter does not love thee least" (I.i.153-154). Lear, however, lacks the insight that Kent has. He only sees what is on the surface, and cannot understand the deeper intentions of the daughters' speeches. As his anger grows from the argument, his foresight diminishes, as he becomes increasingly rash and narrow-minded. When Lear disowns Cordelia, he says, "we/Have no such daughter, nor shall ever see/That face of hers again" (I.i.264-266). He cannot see far enough into the future to understand the consequences of this action. Ironically, he later discovers that Cordelia is the only daughter he wants to see, asking her to "forget and forgive" (IV.vii.85). By this time, he has finally started to gain some direction, and his vision is cleared, but it is too late for his life to be saved. His lack of precognition had condemned him from the beginning. Lear depicts Shakespeare's theme of clear vision by demonstrating that physical sight does not guarantee clear sight. Gloucester depicts this theme by demonstrating clear vision, despite the total lack of physical sight. Before scratching his eyes out, Gloucester's vision was much like Lear's. He could not see what was really going on around him. Instead, he only saw what was presented to him on the surface. When Edmund shows him the letter that is supposedly from Edgar, it takes very little convincing for Gloucester to believe it. As soon as Edmund mentions that Edgar could be plotting against him, Gloucester calls him an "Abhorred villain, unnatural, detested,
Sunday, November 24, 2019
The Discovery of Otzi the Iceman and Its Significance
The Discovery of Otzi the Iceman and Its Significance On September 19, 1991, two German tourists were hiking in the Otzal Alps near the Italian-Austrian border when they discovered Europes oldest known mummy sticking out of the ice. Otzi, as the iceman is now known, had been naturally mummified by the ice and kept in amazing condition for approximately 5,300 years. Research on Otzis preserved body and the various artifacts found with it continues to reveal much about the life of Copper Age Europeans. The Discovery Around 1:30 p.m. on September 19, 1991, Erika and Helmut Simon from Nuremberg, Germany were descending from the Finail peak in the Tisenjoch area of the Otzal Alps when they decided to take a shortcut off the beaten path. When they did so, they noticed something brown sticking out of the ice. Upon further inspection, the Simons discovered that it was a human corpse. Although they could see the back of the head, arms, and back, the bottom of the torso was still embedded in the ice. The Simons took a picture and then reported their discovery at the Similaun Refuge. At the time, however, the Simons and the authorities all thought the body belonged to a modern man who had recently suffered a deadly accident. Removing Otzis Body Removing a frozen body thats stuck in the ice at 10,530 feet (3,210 meters) above sea level is never easy. Adding bad weather and a lack of proper excavation equipment made the job even more difficult. After four days of trying, Otzis body was finally removed from the ice on September 23, 1991. Sealed up in a body bag, Otzi was flown via helicopter to the town of Vent, where his body was transferred to a wooden coffin and taken to the Institute of Forensic Medicine in Innsbruck. At Innsbruck, archaeologist Konrad Spindler determined that the body found in the ice was definitely not a modern man; instead, he was at least 4,000 years old. It was then that they realized that Otzi the Iceman was one of the most amazing archaeological finds of the century. Once it was realized that Otzi was an extremely important discovery, two teams of archaeologists went back to the discovery site to see if they could find more artifacts. The first team stayed only three days, October 3-5, 1991, because the winter weather was too harsh to work in. The second archaeology team waited until the following summer, surveying from July 20 to August 25 1992. This team found numerous artifacts, including string, muscle fibers, a piece of a longbow, and a bearskin hat. Who Was Otzi the Iceman? Otzi was a man who lived sometime between 3350 and 3100 BCE in what is called the Chalcolithic or Copper Age. He stood approximately five feet and three inches high and at the end of his life suffered from arthritis, gallstones, and whipworm. He died at about the age of 46. At first, it was believed that Otzi had died from exposure, but in 2001 an X-ray revealed that there was a stone arrowhead embedded in his left shoulder. A CT scan in 2005 discovered that the arrowhead had severed one of the Otzis arteries, most likely causing his death. A large wound on Otzis hand was another indicator that Otzi had been in close combat with someone shortly before his death. Scientists have recently discovered that Otzis last meal consisted of a few slices of fatty, cured goat meat, similar to modern-day bacon. But many questions remain regarding Otzi the Iceman. Why did Otzi have over 50 tattoos on his body? Were the tattoos part of an ancient form of acupuncture? Who killed him? Why was the blood of four people found on his clothes and weapons? Perhaps more research will help answer these and other questions about Otzi the Iceman. Otzi on Display After seven years of study at Innsbruck University, Otzi the Iceman was transported to South Tyrol, Italy, where he was to be both further studied and put on display. At the South Tyrol Museum of Archaeology, Otzi was encased within a specially made chamber, which is kept dark and refrigerated to help preserve Otzis body. Visitors to the museum can glimpse Otzi through a small window. To remember the place where Otzi had remained for 5,300 years, a stone marker was placed at the discovery site.
Thursday, November 21, 2019
School Uniforms Essay Example | Topics and Well Written Essays - 750 words
School Uniforms - Essay Example If uniforms are not made mandatory, rich students would look down to the poorer students as it gives a chance to them to show-off their wealth. Therefore introduction of uniforms will help to deal with this problem. Therefore there will be no economic differences among the students in the schools. Uniforms will also decrease the violence among students in the students. When students wear the same type of dress the probability of group formation or gang behaviour would be minimum. Uniforms would make schools a safer place for students especially the underprivileged one. Schools uniforms can save much of the time of students because they don't have to waste time in choosing which clothes to wear. Choosing of clothes seems to be a small thing but this really is a big task and consumes actually a hell lot of time. Not only this, we should also consider the time which they spend in malls in order to find the perfect dress. And if the school goers are able to save this time they can concentrate on more important thing like completing their homework or having breakfast. Having uniforms in school would stop the discrimination and teasing on clothing but there are many things to discriminate or tease rather than only clothing like personality, race, colour to name a few. Richer students can tease or look down on the poorer students by having a costly watch or an expensive bag. ... Richer students can tease or look down on the poorer students by having a costly watch or an expensive bag. And therefore uniforms cannot prevent the discrimination or the economic differences. It is only the education which the students get from their parents and teachers which will help them to avoid discrimination on the basis of sex, creed, religion, race or colour. Many feel that making uniforms mandatory would end symbols of being in a gang. But they should understand that there are many ways through which students can show that they belong to a particular gang like rolling up your sleeves or having a band on the hands. Therefore uniforms cannot to a large extent avoid gang behaviour. If uniforms are not made compulsory students can begin to develop their own personal style and they can be more mature. Students will be given the opportunity to decide what they have to wear and therefore this will inculcate the habit of decision-making among the students. Making uniforms compulsory actually violates a student's right of self-expression. The personality of a person (to some extent) is reflected by the clothes he wears so if the students are allowed to choose the clothes which they have to wear they will have an opportunity to express themselves. CONCLUSION Though there are umpteen numbers of arguments both in favour of as well as against making school uniforms mandatory but I personally feel that making school uniforms compulsory would be more effective and efficient in promoting uniformity and equality, in avoiding violence and gang behaviour, in avoiding discrimination on the basis of sex, creed, religion, colour etc and
Wednesday, November 20, 2019
The Great War What were the war aims OR military strategies of the Essay
The Great War What were the war aims OR military strategies of the various belligerents in World War I How was the Great War the first truly global conflict - Essay Example Reflecting on what happened during the Russo-Japanese War, Block felt that this new, technological sort of war would destroy Europe. 1 A new belief circulated amongst European General Staffs that contingency plans needed to be made allowing them to win any future war they might come upon. The main problem that followed from this, however, was the fact that they did not understand the concept of modern war, and thus the plans they put together actually resulted in a catastrophic war of attrition. Four reasons actually caused this catastrophe. The first issue was the fact that industrialization resulted in weapons and equipment being made on a large scale. Next, there was a huge population growth which allowed for the manpower necessary to create the large armies necessary to fight the war. Third, reserves became a popular concept, and this allowed the armies to grow quickly. Last, the creation of large railroad networks allowed for armies to be supplied in the trenches. The combination of these four concepts would alter the face of war forever, and this resulted in a near death struggle by the end of 1914 that neith er country wanted nor expected. Furthermore, none of the European rulers could discover a way to end the terrible war or justify the large amount of men lost to it during the first months of war. Most of them, instead, focused on the next campaign, believing that it would finally win the war-and of course, it never did.2 Each side involved in the war had several issues it needed to face. These issues included figuring out how to mobilize the necessary items in order to actually but together a successful industrial war without completely destroying society as a whole. History indicated that a short, decisive war would be best (the only recent war standing out that stood out in contrast to this at the time was the American Civil War, which at this time was largely ignored as a usual war). The most recent wars, which has included the Russo-Japanese War and the Italian Unification Wars made many believe that modern wars could be quick, fast business forcibly decided by a few short battles. So, there was an overall feeling present in Europe that the European military establishments could win quickly. 3 However, they would be wrong, and they could not have necessarily guessed or understood that they would be. Obviously, they were searching for an answer and looking at things from optimistic perspectives, although they did not necessarily realize this at the time. They are not to blame, because even today, modern historians have problems understanding this war. If one, for example, decides to take a close look at memoirs and study each campaign, the picture simply becomes more and more complex. The only way one can truly understand this war is by taking a close look at military demography, economic systems, labor controls, and transportation theory. One can only understand the Great War by taking a close look via a material assessment in order to lift away obscurity. Therefore, one needs to conclude that three material factors led to the outcome of the war, and these two items include economic mobilization, human and resource mobilization. With this concept in mind, one can understa nd how each coalition developed its strategies to win the Great War. The outcomes of the Great War were serious indeed; the excessive force of economic
Monday, November 18, 2019
Effects of Classical and Post-Classical Religions Research Paper
Effects of Classical and Post-Classical Religions - Research Paper Example With the fall of the empires and their economies, the people had to find means to live and believe in order to proceed with their normal lives. People then got the chance to migrate to different areas and meet new people, develop new ideas and learn new and diverse ways of life. Religion would not have come at a better time for them since it enabled them have a venue to express their beliefs and needs. Christianity being one of the religions was embraced by people and they henceforth developed allegiances in accordance with the different religions that they embraced. Eastern mediteranian, for example, enjoyed the aftermath of the Roman empire’s collapse as it opened trade and opportunities for them . Politically, the rise of Christianity saw changes in leadership styles and allegiances. The previous empires like the Roman empire always dictated and demanded that people worked with allegiances sworn to the leardership. This changed with the belief that were embraced by the chri stian teachings. The teachings enabled and required people to work together with others to collectively help improve their lives and in unity to build a strong kingdom of God . The supreme being was nolonger the emperor, but God. These religious people happened to be in regions that identified with the religion that was more dominant. Christianity did institute within its gorvenance structure and formation tactics borrowed from the Roman empire. Cultural and artistic ways and lives of people also changed.... The teachings enabled and required people to work together with others to collectively help improve their lives and in unity to build a strong kingdom of God 3. The supreme being was nolonger the emperor, but God. These religious people happened to be in regions that identified with the religion that was more dominant. Christianity did institute within its gorvenance structure and formation tactics borrowed from the Roman empire. Cultural and artistic ways and lives of people also changed with the transition of the society into the religions of salvation. The Roman empire, for instance, had their gods that they would offer sacrifices to in times of their needs. They belived that the gods were many and that every god had a purpose, authority and power to reward and punish those who did not heed to or obey them. Christianity, on the other hand, came up with the teaching that the last sacrifice was that of the death of Jesus Christ and that there was only one GOD 4. This brought about c onflict of interest and cultural discomforts, as well as disagreements between the emperors and the christians resulting in christians being prosecuted. Christianity introduced a way of life in which people lived together in harmony and peace. It brought forward a community that preached against violence and discrimination. On the other hand, the previous empires used coercion, divide and rule kind of leadership that only benefited those in power. Social lives of the people received a great change and boost, one that the people found easy to embrace as it cared for the well being. However, the leadership was immensely affected since their ways of gaining more power and strength was being overshadowed by the strong beliefs that the people developed.
Friday, November 15, 2019
Administration of Colonoscopy Reflective Account
Administration of Colonoscopy Reflective Account This essay aims to provide a reflective account of the authors personal and professional experience of a patient being admitted for a colonoscopy. To achieve this, a model of reflection will be used and a rationale provided to support this choice. The main point of discussion is communication and advocacy. Advocacy is central to communication and part of a caring nurse-client relationship (Arnold Boggs, 2003). The author as a newly appointed nurse on the Endoscopy Unit, will reflect upon how they could have been a better advocate for the patient in question. Ethical and legal issues will be examined. Finally implications for practice will be discussed. Using a model of reflection allows the nurse to re-appraise the care they have delivered to a patient/client and in doing so can evaluate the effectiveness of that care (Basford Slevin 1995), thus with the intention of influencing future practice for the better. Before starting the reflection process it will be more helpful for the professional to have a guideline or framework from which to work from (Palmer, Burns and Bulman 1994). Palmer et al (1994) view the process as something that is dynamic and they advise a cyclical style model using questions to provide a format for reflection. It is for these reasons that the Gibbs Reflective Cycle has been chosen (Gibbs 1998) for this essay. In accordance with the Nursing and Midwifery Council standards on respecting confidentiality in practice, all names and locations have been made anonymous (NMC 2008). As this is a reflective essay the author will refer to herself as I where appropriate. The reflective cycle is divided into six sections each with their own key questions. These are: Description: What happened? Feeling: What were you thinking and feeling? Evaluation: What was good or bad about this experience? Analysis: What sense can you make of the situation? Conclusion: What else could you have done? Action Plan: If it arose again what would you do? (Gibbs 1998) These areas for reflection provide the main topics for the rest of this assignment. When the practitioner has developed an action plan they can then return to the beginning of the cycle with the extra knowledge they have obtained from the first reflective experience (Gibbs 1998). It is here though with the description of the incident that the reflective cycle will begin. The following situation led me to question my actions when admitting a patient for a colonoscopy. The patient a 43 year-old male was referred for a colonoscopy by his GP following a three-week history of fresh rectal bleeding, anal itching (pruritus ani) and a change in bowel habit. Two weeks prior to the scheduled test, a pack containing a letter of appointment was sent to the patient by the endoscopy administration staff. Enclosed were two sachets of Picolax bowel preparation, full instructions for usage, highlighting the need to follow instructions precisely to ensure clarity of view and aid diagnostic accuracy. Included with this pack was a pre-endoscopy questionnaire to enable the nurse to assess the patients general state of health and identify any potential risk factors or complications, which may arise. A booklet was in this pack explaining the procedure, reasons for the test, complications and risks and what to expect during the test. The booklet stated other available investigations in order that he could make an informed decision and enable him to give informed consent for the test to go ahead. The Nursing and Midwifery Council (NMC) (2008) state that before any treatment or care is given to the patient, consent must be obtained. The BSG (2008) warn that consent issues are a major source of problems, sometimes leading to both complaints and litigation throughout the NHS. Therefore valid and robust consenting is now a required standard for the Endoscopy Global Rating Scale (GRS, 2009) which is a tool that enables endoscopy units to assess how well they provide a patient-centred service. Information in the booklet covered the option of sedation and the need for appropriate after-care. A consent form was enclosed for him to sign at home, providing the patient had read, understood an d agreed to under-go the procedure. A morning appointment was made for the patient and he arrived at the unit by himself. He was greeted by myself, I checked his personal details. This is in accordance with the BSG (2008) guidance for obtaining a valid consent for elective endoscopic procedures as it states that identity checks at key stages in the procedure are essential as some patients have even been known to undergo procedures intended for another due to loss of autonomy and anxiety which can result when entering the hospital. When this information was confirmed he was made to feel comfortable in the preparation room. The patient was clearly anxious. He was looking down a lot and he had his arms folded. He spoke very quickly and with a quiver in his voice one of the first things he said to me was, please knock me out for this. I explained to the patient that although we could give him some sedation which would make him feel more relaxed, he would still be awake as it would be unsafe to knock him out for the test. The sedation used for all endoscopic procedures is conscious sedation. This has been defined as: A technique in which the use of a drug or drugs produces a state of depression of the central nervous system enabling treatment to be carried out, but during which verbal contact with the patient is maintained throughout the period of sedation. The drug and techniques used to provide conscious sedation should carry a margin of safety wide enough to render loss of consciousness unlikely. BSG (2003, p3). He explained that he saw on the consent form that sedation would be offered and he interpreted this to be a general anaesthetic. I further explained to him that although the patient may feel sleepy, he would be conscious throughout the test and he would be able to talk to us. Cotton and Williams (2003) agree, believing that the desired effect of the sedation on the patient is sleepy, relaxed but rouse able. The patient clearly expressed a preference for sedation and it was established that the patients wife could collect him after his procedure and would remain with him over the next 24 hours. It is a requirement that any patient undergoing a procedure with sedation should be accompanied home by a responsible adult who will remain with them for 24 hours as sedative effects are known to remain in the body system for up to this period of time (Royal College of Surgeons, 1993). At this point, I as a newly appointed staff nurse on the unit was unsure whether the consent form that the patient had signed was valid as he originally thought that he was going to have a general anaesthetic when he had signed the form. I had been trained in taking consent which is documented in my e-portfolio as regards the national GIN training programme (Gastrointestinal in Nursing Training Programme), but was unsure what to do in this instance as I had never experienced the situation before. My initial thought was that is was not valid as the patient had a different perception of the test. I explained to the patient that I was just going to get some advice from my colleague (who had worked in the endoscopy unit for several years) as regards the validity of his consent form. I said that I would need to explain the situation to my colleague and he agreed to this joking that we did not both want to get into trouble from the headmaster and get a detention. I said that I would only b e a couple of minutes and left the room to find advice. I explained the situation to the nurse who was sat in recovery. The nurse said that the Endoscopist performing the procedure would go over consent again in the procedure room and not to worry about it. I expressed concern at this because I knew that consent must never be obtained in the procedure room. Guidelines readily available in relation to consent include British Society of Gastroenterology guidelines (BSG) (2008) and the Joint Advisory Group Guidelines (JAG) (2001). Booth agree that consent should not be taken in the procedure room. Guidance on good practice in consent implies that all patients must have had adequate time to absorb and reflect upon new information. This is not achieved if consent is obtained at the last possible moment which is in the procedure room itself. The nurse was dismissive and made unpleasant comments regarding men in general. There was a short distance between the nurse and the preparation room where the patient was so it is likely that the patient heard her remarks. I did not comment at this time even though I felt her remarks to be inappropriate. Luckily this gentleman was the first patient on the mornings list and as such, no other patients were in recovery to here the comments. The nurse picked up the patients notes and knocked on the preparation room door. I thought that I had better observe too as the nurse looked ready for a challenge. The nurse was very brusque in manner and asked the patient if he had read the booklet which the unit has sent out for the test and the section regarding sedation. The patient said that he had read the booklet and indeed the section regarding sedation but there was no mention that he would be awake after he had been given the sedative and assumed therefore that he would be asleep. The nurse then got a copy of the booklet. As she was flicking through trying to find the page with the relevant sedation information on, she said it clearly states in the booklet that if sedation is given, the patient will be awake throughout the test. However, when she got to the page regarding sedation there was no mention of this. It just stated that sedation would be offered prior to the colonoscopy but if the patient decided to have sedation that it was essential that someone was available to stay escort the patient home and stay with them overnight. The nurse went bright red, but did not apologise to t he patient and said that she was going to have words with the administration staff and left the procedure room. I felt guilty that I had not challenged the nurse regarding her rude manner with the patient at the time but felt intimidated and unable to voice my opinion, I also felt I had failed in my duty of care. I thought that the nurse had made a big deal when there was no need. I apologised unreservedly for my colleagues attitude and said that I would take steps to make sure that the booklet was clearer. I then realised that my original question regarding the consent form had not even been answered. I asked the patient if it was okay if I asked another colleague their opinion. The patient said yes but not that do-lally nurse and said that he would be making a complaint regarding her attitude. I then found the endoscopist who was actually going to be undertaking the patients test and asked them about the consent issue. They said that the consent form was fine as long as I reiterated that the patient would be awake and that they fully understood the test. The Endoscpist said that they would d iscuss the consent form with the patient again prior to the procedure as this is normal practice. I went back into the preparation room and said that the consent form was not a problem and that we would discuss it further. I spoke to the patient in a reassuring way, trying to compensate from his previous treatment from my colleague. I asked the patient if he understood the test he was about to have and its related risks. When I felt like the patient had a clear understanding of the procedure I asked him if he had any questions regarding the procedure, the patient replied he had no further questions. He added that he was even more nervous now after the experience with the nurse but just wanted it to be over as quickly as possible. I began to explain the procedure that he was going to undergo and asked if he knew why the GP had referred him for this procedure and relayed the benefits of viewing the bowel in this way. The patient was happy that a diagnosis might be forthcoming from this test. I then reiterated the possible risks of the procedure to the patient explaining that they w ere rare but never the less very real. The patient said that he understood the risks involved but wanted to go ahead with the test to obtain a diagnosis of his problems. I stated that if the patient was going to have sedation, then he should not drive or operate any machinery and should not sign any legally binding documents as the side effects from the sedation would still affect him for twenty four hours. I explained that the endoscopist would endeavour to complete the investigation however, if complications were to occur such as patient distress or poor bowel prep that the test would be abandoned. During a Gastrointestinal Endoscopy and Related Procedures Course at The University of Sheffield (Feb 2010, SNM 2215/3232) it was suggested that the guideline for informed consent was signified by the acronym EMBRACE, Explanation of the procedure, Motive for the procedure, Benefits, Risks, Alternatives, Complications and side Effects of the procedure. I believe that these guidelines were fully complied. Following the taking of a medical history and completion of a further in-depth health check questionnaire to ascertain any condition or reason to which sedation would be contraindicated such as elderly patients who may have significant co-morbidity and even in younger patients, the presence of heart disease, cerebrovascular disease, lung disease, liver failure, anaemia, shock and morbid obesity (BSG, 2003). It became evident that sedation would be an option. I explained to the patient that a nurse would be with him continuously throughout the procedure and would encourage him to breathe through any discomfort he may feel, or to push some of the air out of his bottom to relieve any pain. The patients blood pressure, pulse and saturations were taken and all were within acceptable limits. This provides a good baseline of the patients observations for the procedure itself and can determine any changes that may occur as a result of the cardio or respiratory depression that may be induced by sedation. Pascarelli (1996) states that during the procedure, the nurses primary responsibility is to monitor the patients vital signs along with communication with the endoscopist, administration of medications and emotional support to the patient. Clarke (1994) warns that patients who undergo invasive procedures are usually anxious and their vital signs are commonly elevated however the sedation lessens the anxiety, and all of the vital signs decrease therapeutically to that patients resting level. The sedation of choice in my workplace is intravenous Midazolam. Midazolam is a benzodiazepine reputedly well suited for use in endoscopy. It has an amnesic affect causing a reduction in memory recall. Clarke (1994) agrees saying that the goal of IV conscious sedation is some degree of amnesia. Patients will occasionally remember some parts for example, the initial introduction of the colonoscope. It is for this reason clear written discharge instructions are given to the patient prior to discharge, with a contact telephone number in the event of any problems and this was explained to the patient. Sedation may be indicated for many reasons. In the main these may include allaying of fears regarding a procedure, and aims to facilitate compliance with repeat procedures as a result of the amnesic affects induced. In many cases it assures co-operation and eases difficulties for the endoscopist and generally provides a rapid, safe return to the normal activities of daily living. The patient was asked to undress from the waist down and to put on the gown provided. When the patient was ready he was taken by myself into the procedure room and introduced to the endoscopist and the appointed staff nurses where the issues of consent and sedation would once more be discussed with the patient as it is the endoscopists ultimate responsibility. Throughout the experience, I felt that several important issues had been highlighted. One issue is that of the booklet that is sent out to the patients prior to the test. I believe that individual patients perspectives regarding the effects of sedation may vary greatly, from a mild sedative to a general anaesthetic. I conclude this to result from the individual interpretation of patient information received and relatives and friends giving a distorted image of their own experience due to the amnesic affect of the sedation. I would advocate good effective communication skills are paramount in allaying misconceptions and fears and the giving of a realistic overview is therefore essential. It was clear that there needed to be some improvement of the explanation of conscious sedation as I felt that is merely skimmed the surface explaining that the option of sedation was there and that there needed to be someone to escort the patient home and stay with them overnight. I felt that it needed to be clearer in the fact that it needs to mention that the patient will not actually be anaesthetised and furthermore that amnesia is a common side effect from the sedation given. This has subsequently been mentioned to the ward sister and the booklet has been updated to clarify conscious sedation. Perhaps one of the most obvious issues is that of the attitude of the other nurse. The BSG (2008) state that the patient must not be put under any pressure and have sufficient time to digest the information in order for consent to be valid. I felt that the attitude of the nurse in question did put pressure on the patient and caused further anxiety for the patient. I felt that the nurse spoke to the patient in a degrading way and showed a lack of professionalism. The Nursing and Midwifery Council (NMC 2008) state that nurses must treat people as individuals and respect their dignity, must not discriminate and must treat people kindly and considerately. This was not the case in the above example. The Equality and Human Rights Commission (2008) state that no matter your circumstances you should always be treated fairly and with respect when using healthcare services. The Department of Health (2008) cite the UK Human Rights Act in their guidelines about human rights in healthcare when they state that people have an absolute right not to be treated in a degrading way. This means that it is unlawful for the NHS organisations to act in a way that is incompatible with the human rights act. Endoscopy nurses and indeed all NHS staff should be thinking about their practice and how their response to a situation may impact on a patient or clients human rights. If the patient had chosen to complain (as he said he was going to do) about the nurses attitude towards him, then the nurse may have well been in trouble. This experience has made me question my future practice as a registered nurse and how I would deal with a similar situation. Arnold and Boggs (2003) suggest that an advocate is someone who speaks out; supporting a person so that their views are heard and their rights are upheld, with the sole purpose of maximising the patients health. I was not assertive as I did not defend the patient and therefore did not fulfil my duty of care by becoming an advocate for the patient, ensuring he was treated with dignity and respect. I was worried about what may happen if I challenged the nurses practice. I need to develop my assertiveness and be able to communicate confidently and effectively with both patients and health care professionals. It is quite easy for a nurse to be an advocate for the patient when there is no stress involved but it can be quite difficult when it goes against other health professionals (Kendrick 1994). In this instance there was a conflict between the patients best inter est and my fear of challenging the nurse. If I had been a more experienced nurse on the endoscopy unit and known the nurse involved in this situation better, I think I may have been able to foresee her reaction to the patient and perhaps may not have approached this particular nurse or used my communication skills together with advocacy to diffuse the situation. Gates (1994) states advocacy is one of the main responsibilities nurses have; it is part of communicating on behalf of the patient and/or their families, acting as a mediator to express their needs and experiences. In health care, communication is fundamental to promoting the safe and effective care of patients. The Department of Health Knowledge and Skills Framework (KSF) (DoH 2004) is a competence framework to support professional development and career progression through the NHS and is about lifelong learning. It has core dimensions essential to providing quality care. Core dimension 1 (level 4) is concerned with communication. It states that the purpose of communication may include advocating on behalf of others. In order for me to progress as a nurse on the endoscopy unit I need to be familiar with and work within the KSF and other guidelines. On reflection, I feel that I did communicate with the patient well. Smith (1995) proposes that reflection does not necessarily entail an incident that was dramatic or negative; it could easily be something positive that a person finds they obtain valuable learning experience from. Communication with the patient has to be one of the most important aspects of nursing care. An integral part of this process is the way a nurse should use and understand body language (Wilkinson 1991). It is as vital a part of the communication process as speaking and should be treated as such. Body language can convey all human emotions either consciously or not and can show a persons true feelings regardless of what they have said (Pease 1984). I could tell by the way that the patient was communicating non-verbally that he was anxious. His facial expressions and posture showed the classic signs of someone being anxious (Teasdale 1995). Seeing this, perhaps I should have explained to the nurse beforehand t hat the patient was anxious so that she may have acted with a bit more respect towards the patient. It is clear that good clear communication skills can improve patient satisfaction and compliance, thus reducing anxiety. I believe that during the admitting process with the patient I did actively discuss the procedure with the patient. I felt that I gave the patient opportunity to ask questions and allay any fears he was harbouring. I sat beside the patient and spoke to him about the procedure in an informal and pleasant manner, giving him opportunity to voice any concerns that he had. I believe that the patient is at their most vulnerable and anxious upon entering the endoscopy unit and some encouraging reassurance makes the patients experience less of an ordeal. It is my opinion that an assessment of a patients personality and level of understanding regarding consent and sedation enables the development of a communication strategy accordingly thus providing a sound knowledge of the test, sedation offered and therefore informed consent. This essay has allowed me to reflect upon my own practice and how I should have acted differently by standing up for the patient at the time, not allowing my own lack of confidence to prevent this. I understand that the care of the patient is my first concern and that I must work with others as a team to protect and promote the health and wellbeing of those in my care (NMC 2008). Perhaps with this understanding, I will be less anxious about felling inferior around other professionals. I will articulate my professional judgement given a similar situation, using what I have been taught which is the best evidence based practice to rationalise my reasons for questioning their practice. I will aim to develop my assertiveness (as I realise that assertiveness does not come naturally to me) to speak out in the interests of the patient, whatever the situation. I will develop my ability to communicate with both patients and other professionals to offer them the opportunity to rationalise their own care delivery and reflect upon it. I believe these actions will enhance my professionalism and promote best practice, in the interest of the patient. I had chosen to focus on communication and advocacy as these are areas in which I feel I need to work on. Gibbs (1998) reflective cycle was used in this assignment because it is a familiar tool that I have found to be useful and uncomplicated. Learning from an experience and then reflecting on that experience is an excellent way of improving the skills in my chosen profession (Kolb 1984). From my own personal point of view, I went into this assignment with some degree of emotional imbalance for the fact that I did not speak out for the patient but now I feel that I have gained in several areas. I feel my reflective skills have increased and with it my confidence regarding tackling such situations again. Also I feel more relaxed with the idea of reflecting uncomfortable incidences because I can see the benefits in doing so.
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