Individual Dreamweaver Lessons Coursework Example | Topics and Well Written Essays - 500 words

Individual Dreamweaver Lessons - Coursework Example Below is the structure of a web page saved as htm or htlm file. We also covered CSS designer. The lecture touches on Live view and Live code that help in giving the exact review of the web page designed and how visually changing the web page developed will affect the code behind the scene. The first lesson also gives an overview how you can create a hyperlink on a web page. The tag â€Å"† was used to create a hyperlink. Use bar to link section of the documents to other pages. For example, In this lesson, creating of a new site took the center stage by defining site setting using Site Setup dialog box. The Servers, Versions as well as advanced setting options used in defining your site. This lecture also declared the DOCTYPE used in HTML5 which is . The lesson also looked at the format of saving the new site created. The file created should have â€Å"html† file format and only special characters such as underscores (_) is used to separate the words. You should save it on one major folder. CSS helps in defining appearance of a web page. You can set background color or link color whichever applicable using CSS. It was important to note that Document Type set to HTML5 is set as Unicode (UTF-8) and that Adobe Photoshop is being used in a tracing image such as JPEG and GIF. We looked at local root folder on how one can copy, select, view or open files from it. It also addresses graphic file types being displayed by web browsers. The graphic files discussed include GIF that condenses color images and used mostly in areas with flat colors like logos. JPEG format is used in inline images. When inserting a logo/image, use the format. You can then set logo/image width and length. Inserting of Photoshop smart objects in an html form was also tackled. Use in group-block elements. When using HTML tables use attributes such as dl, dt, and

Education mis in East African countries - Tanzania Dissertation

Education mis in East African countries - Tanzania - Dissertation Example The creation of the MIS model will serve the purposes of empowering decision makers and the creation of capacity to deliver better education services across the sector. In the area of requirements analysis, the creation of the specification for the MIS model was executed through incorporation of national and international standards of education, regarding the needs of the users of the Tanzanian education sector. Communication with the users was executed through interviews, as this model offered unbiased information on the viewpoints of the user population. Feedback surveys were also helpful towards reaching the desired information base, as collected from social networking and other ICT-related data sites. Areas of constraints included the vague knowledge of the specifications desired by the user population, the unreasonable timelines of the end-users, and the communication gap between implementation teams and the end-user population. The rationales for the choices made were based on rationale capture and rationale representation, which were verified using argument-based choices. The software requirements specification was designed to emphasize on and foster the usage of management information systems throughout the creation, processing and consumption of information. Performance indicators revolved around the service delivery of service personnel to the documentation of students, and offering a complete picture of the educations sector. The features of the model under implementation include capturing baseline statistics like the demography of users to school performance capacities. Data flow across the sector was created to improve the practice and quality of management across the different user groups. The schedule for the implementation of the model will extend across 2011 and 2012, prior to expansion depending on the depicted implementation needs and uptake capacity. Under design specification, the model was split into two sub-phases: the top level design an d the detailed design level. The implementation of the model covered the development of the model, creation of data collection forms, data entry models and checking of the quality of the application. In the area of testing, the MIS model was tested on a number of areas, including the presence of bugs, model usability, and model compatibility. The model will offer a platform from which the education sector can run in a more effective manner, following the more effective transfer and communication of relevant information across the sector. INTRODUCTION AND DESCRIPTION OF THE FUNCTIONALITY OF THE MIS MODEL UNDER CREATION The education sector at Tanzania has historically faced numerous challenges, including the lack of basic infrastructure like electricity at local

Wireless Led Dot Matrix Notice Board Essay Example for Free

Wireless Led Dot Matrix Notice Board Essay POWER SUPPLY Power supply section power the whole circuitry. Different section of this system requires different voltage levels. This requirement cannot be achieved using a single power adapter or battery. So a power supply consist of dc-dc converter is used in our project. The DC-DC converted dc power supply can provide 12v dc, 9v dc and 5 v dc simultaneously for display, discrete IC and micro controller respectively. The power supply section is also included with short circuit protection to prevent system being damaged due to the careless usage or electrical malfunctions. CONTROLLER The controller used here is PIC 16f877a, which is an 8 bit micro controller used for general purpose medium scale applications. In our project this device retrieves signals from the RF receiver as serial data through its URAT port on a baud rate of 2400 bps and stores in its internal data memory. From there it sends the data one by one to display section to display it. The scrolling algorithm is also done through the program written in the controller. This controller also communicate with the RFID reader to fetch the ID of RFID card brought to its proximity and then retrieves the corresponding registry entry to display it in the display board. The scrolling message mode and personal message mode is switched with help of two way switch attached in the display board end. When the switch is in its normal position the message from the PC is displayed and when the switch is in other position the board will display the personal information of the  student whose card is in the proximity o f the RFID reader. DISPLAY The display used here are dot matrix LED. The whole panel consist of 32 displays each one of 57 dot matrix LED. Each character in this display is formed using four such display units. That means the whole display can show a total of 8 characters at a time. The display is drived and controlled using a ring counter IC 4017. By this IC we select each display independently and their column. It uses persistence of vision to let you drive the 32 led matrixes with only 10 microcontroller outputs! Normally you would need 32outputs for 32 LEDs but by using multiplexing and a helper chip you can get away with 10. LED Display multiplexing simply means turning on one led for a short period of time and doing this repeatedly for each LED. If you do this fast enough then your eye will not notice any flicker.The LEDs are no different to any other LEDs but it saves a huge amount of soldering as all the wiring has been done for you..Or you could wire it up yourself if you cant get hold of the module. Still only need 10 control wires (just wire you leds the same as shown in the module diagram). Your eye reacts slowly to changes in light intensity so that if a light is turned on and off quickly enough then it does not notice that the light is off. Basically your eye remembers a light pulse for a short time. The approximate time is 20ms so if the light is turned on at a frequency 50Hz ( 1/20ms) then your eye will not notice any flicker at all. Multiplexing uses this fact to reduce the number of pins needed to drive an LED display. You can do this by splitting the 32led displays into 7 rows and 5columns which lets you drive it using 7 row outputs and 5 column outputs. In fact the 57 led matrix block used here has all the leds arranged in this way already. Each row is driven in turn and as long as all of the rows are driven within a time period of 20ms it will appear as though the LEDs are on continuously. To turn a specific led ON, data is output to the column drivers when a row is driven. To save more pins it is common to use a helper chip and in this project it is a Johnson counter (a 4017). This generates a walking one every time that its clocked.  Since you only want one row on at a time it is the ideal chip for this application. In this project when the 4017 has been reset it outputs logic high at Q0 which is not connected so during reset the 4017 does nothing. This allows you to use the column driver port for something else if you want to when you are not driving the LEDs.To drive the 4017 all you need is two pins one for reset and one for clock. So to fully drive the 32 matrix led display you need only 4 4017. The most difficult thing about using the dot matrix LED display is defining the characters. Basically for ASCII characters you need an array of 128 blocks each having 8 column data numbers. The usual way is to get out a piece of graph paper and define your characters by drawing blocks where a pixel is on. You then translate each line into hex (binary to hex is very easy) and then transfer this information to your program source code. RFID READER RFID is used here to implement the personal information display. RFID technique helps the system for identifying each student with the help of a unique ID given to each student. This reader is capable of powering and reading data from an RFID card which is brought ot its proximity. It has a transmission section through which it sends the received data to controller. The range of this RFID is approximately about 10 cm so that it can avoid unwanted detection of RF signals. In our system RFID system consists of a reader and one or more tags. The readers antenna is used to transmit radio frequency (RF) energy. Depending on the tag type, the energy is harvested by the tags antenna and used to power up the internal circuitry of the tag. The tag will then modulate the electromagnetic waves generated by the reader in order to transmit its data back to the reader. The reader receives the modulated waves and converts them into digital data. In the case of the Parallax RFID Reader Module, correctly received digital data is sent serially through the SOUT pin. There are two major types of tag technologies. Passive tags are tags that do not contain their own power source or transmitter. When radio waves from the reader reach the chip’s antenna, the energy is converted by the antenna into electricity that can power up the microchip in the tag (known as parasitic power). The tag is then able to send back any information stored on the tag  by reflecting the electromagnetic waves as described above. Active tags have their own power source and transmitter. The power source, usually a battery, is used to run the microchips circuitry and to broadcast a signal to a reader. Due to the fact that passive tags do not have their own transmitter and must reflect their signal to the reader, the reading distance is much shorter than with active tags. However, active tags are typically larger, more expensive, and require occasional service. The RFID Reader Module is designed specifically for low-frequency (125 kHz) passive tags. Frequency refers to the size of the radio waves used to communicate between the RFID system components. Just as you tune your radio to different frequencies in order to hear different radio stations, RFID tags and readers have to be tuned to the same frequency in order to communicate effectively. RFID systems typically use one of the following frequency ranges: low frequency (or LF, around 125 kHz), high frequency (or HF, around 13.56 MHz), ultra-high frequency (or UHF, around 868 and 928 MHz), or microwave (around 2.45 and 5.8 GHz). Here we are using an RFID Reader Module with a single TTL-level. The current consumption of the module will increase dramatically when the module is active. A visual indication of the state of the RFID Reader Module is given with the on-board LED. When the module is successfully powered-up and is in an idle state, the LED will be GREEN. When the module is in an active state and the antenna is transmitting, the LED will be RED. The face of the RFID tag should be held parallel to the front or back face of the antenna (where the majority of RF energy is focused). If the tag is held sideways (perpendicular to the antenna) youll either get no reading or a poor reading. Only one transponder tag should be held up to the antenna at any time. The use of multiple tags at one time will cause tag collisions and confuse the reader. The two tags available in the Parallax store have a read distance of approximately 3 inches. Actual distance may vary slightly depending on the size of the transponder tag and environmental conditions of the application. When a valid RFID transponder tag is placed within range of the activated reader, the unique ID will be transmitted as a 12-byte ASCII string via the TTL-level SOUT (Serial Output) pin in the  following format: RF RECEIVER The RF receiver is used to receive RF wireless signals which are transmitted fro the pc section and feed it to the controller. This receiver works in the principle of ASK modulation, an analogue modulation technique to implement digital transmission. This receiver has an active antenna. It works with power of 5V and sink a current of 0.1 mA. The maximum baud rate allowable with this receiver is 2400 bps. For efficient operation we uses 1200 bps. The range of this receiver is with in 100 mtrs. But it can be extended to kms be increasing the power of transmitter . PC SECTION PC section contains application software which is used to interface with the computer. This application has a text box where we can enter the message to be displayed in the notice board. On hitting the send button the data in the text box is transmitted to the display board wirelessly. RS 232 – TTL CONVERTER The signal obtained from th PC is of RS 232 standard. Which means the signal from the PC will be in the range of +12 to -12V level. For the transmitter and the controller to understand the signal it should be in the range of 0 +5 V. so the signal should be level converted before transmission. For this level conversion we use MAX 232 IC. This IC is dedicated for RS 232 to TTL level conversion. With the help of some discrete components this IC can convers the level to ttl logic. RF TRANSMITTER RF transmitter transmits the digital signal generated by the level converter through space as electromagnetic waves. The transmitter uses ASK modulation technique. The range varies up to 100mtrs. The power varies from 5V to 12v. The more the power supply voltage the more will be its quality and range.

Procedures For Drill String Design Engineering Essay

Procedures For Drill String Design Engineering Essay This chapter presents general procedures for drill string design. The design aspects of critical importance and factors controlling drill pipe selection are highlighted. The term Drill Stem is used to refer to the combination of tubulars and accessories that serve as a connection between the rig and the drill bit (RGU lecture slides). It consists mainly of Drill Pipe, Drill Collars (DC) and Heavy Weight Drill Pipes (HWDP) and accessories including bit subs, top drive subs, stabilisers, jars, reamers etc. Drill stem is often used interchangeably with the term Drill String which actually refers to the joints of drill pipe in the drill stem. For the purpose of this report, Drill String will be used to refer to the string of drill pipes that together with drill collars and heavy weight drill pipe make up the drill stem see fig 3.1. 3.1 DRILL STEM COMPONENT DESCRIPTION 3.1.1 Drill Pipe The drill pipes are seamless pipes usually made from different steel grades to different diameters, weights and lengths. They are used to transfer rotary torque and drilling fluid from the rig to the bottom hole assembly (drill collars plus accessories) and drill bit. Each drill pipe is referred to as a joint, with each joint consisting of a pipe body and two connections (see fig 3.2). Drill pipe lengths vary, and these different lengths are classified as ranges, the available or more common ranges include: Range 1: 18 22 ft Range 2: 27 30ft Range 3: 38 40ft. Drill Stem. Fig 3.1: Drill Stem with components. (Heriott Watt University lecture Notes: Drilling Engineering) Drill pipes are also manufactured in different sizes and weights which reflects the wall thickness of the drill pipe. Some common sizes and their corresponding weights include 31/2 in. 13.30 lb/ft and 4 1/2in. 16.60 lb/ft. The indicated weight is the nominal weight in air (pipe body weight excluding tool joints) of the drill pipe. A complete listing of API recognised drill pipe sizes, weight and grades are published in the API RP 7G. The drill pipe grade is an indication of the minimum yield strength of the drill pipe which controls the burst, collapse and tensile load capacity of the drill pipe. The common drill pipe grades are presented in the table below Grade Yield Strength, psi Letter Designation Alternate Designation D D-55 55,000 E E-75 75,000 X X-95 95,000 G G-105 105,000 S S-135 135,000 Table 3.1: Drill Pipe Grades. Drill pipes are often used to drill more than one well, therefore in most cases the drill pipe would be in a worn condition resulting in its wall thickness being less than it was when the drill pipe was brand new. In order to identify and differentiate drill pipes, they are grouped into classes. The different classes are an indication of the degree of wear on the wall thickness of the drill pipe. The classes can be summarised as follows according to API standards: New: Never been used, with wall thickness when to 12.5% below nominal. Premium: Uniform wear with minimum wall thickness of 80%. Class 2: Allows drill pipe with a minimum wall thickness of 70%. It is essential that the drill pipe class be identified in drill pipe use or design, since the extent of wear affects the drill pipe properties and strength. When specifying a particular joint of drill pipe, the class, grade, size, weight and range have to be identified, the specification could therefore appear thus: 5 19.5 lb/ft Grade S Range 2 Fig 3.2: Parts of Drill pipe. (Handbook for Petroleum and Natural gas) 3.1.2 Tool Joints Tools joints are screw type connections welded at the ends of each joint of a drillpipe. The tool joints have coarse tapered threads and sealing shoulders designed to withstand the weight of the drill string when it is suspended in the slips. Tool joints are of two kinds; the pin (male section) and the box (female section). Each drill pipe has a pin attached to one end and a box attached at the other end. This makes it possible for the pin of one joint of drill pipe to be stabbed into box of a previous drill pipe. There are several kinds of tool joints widely used: Joint Type Diagram Description Internal Upset (IU) Tool joint is less than the pipe. Tool joint OD is approximately the same as the pipe. Internal Flush (IF) Tool joints ID is approximately the same as the pipe. The OD is upset. Internal / External Upset (IEU) Tool joint is larger than the pipe such that the tool joint ID is less than the drill pipe. The tool joint OD is larger than the drill pipe. Table 3.2 Types of tool joints. (The Robert Gordon University Lecture Notes: Drill String Design) 3.1.3 Drill Collars Drill collars are thick walled tubes made from steel. They are normally the predominant part of the bottom hole assembly (BHA) which provides Weight on Bit (WOB). Due to the large wall thickness of the drill collars, the connection threads could be machined directly to the body of the tube, thereby eliminating the need for tool joints (see fig 3.3). Drill collars are manufactured in different sizes and shapes including round, square, triangular and spiral grooved. The slick and spiral grooved drill collars are the most common shapes used currently in the industry. There are drill collars made from non-magnetic steel used to isolate directional survey instruments from magnetic interference arising from other drill stem components. The steel grade used in the manufacture of drill collars can be much lower than those used in drill pipes since they are thick walled. Functions Provide weight on bit Provide stiffness for BHA to maintain directional control and minimise bit stability problems. Provide strength to function in compression and prevent buckling of drill pipes. Fig 3.3: Carbon Steel Drill Pipes. 3.1.4 Heavy Weight Drill Pipe Heavy weight drill pipes (HWDP) are often manufactured by machining down drill collars See fig 3.4. They usually have greater wall thickness than regular drill pipe. HWDP are used to provide a gradual cross over when making transition between drill collars and drill pipes to minimise stress concentration at the base of the drill pipe. These stress concentrations often result from: Difference in stiffness due to the difference in cross-sectional area between the drill collar and drill pipe. Bit bouncing arising from rotation and cutting action of the bit. HWDP can be used in either compressive or tensile service. In vertical wellbores it is used for transition and in highly deviated wells, it used in compression to provide weight on bit. Fig 3.4: Heavy Weight Drill Pipe. (Heriott Watt University lecture Notes: Drilling Engineering) 3.1.5 Accessories Drill Stem accessories include: Stabilisers: these are made of a length of pipe with blades on the external surface. The blades are spiral or straight, fixed or mounted on rubber sleeves to allow the drill string rotate inside. Functions of the stabiliser include: Stabilise the drill collars to reduce buckling and bending Ensure uniform loading of tricone bits to reduce wobbling and increase bit life. To provide necessary wall contact and stiffness behind the bit to induce positive side force to build angle when drilling deviated wells. Reamers: used in the BHA to enlarge the well bore diameter and ream out doglegs, key seats, ledges. Drilling Jars: incorporated in the BHA to deliver a sharp blow and assist in freeing the drill string should it become stuck. 3.2 DRILL STRING DESIGN The drill string design is carried out in order to establish the most efficient combination of drill pipe size, weight, and grades to fulfil the drilling objectives of any particular hole section at the lowest cost within acceptable safety standards. In order to design a drill string to be used in a particular hole section, the following parameters need to be established: Hole section depth Hole section size Expected mud weight Desired safety factors in tension and overpull. Desired safety factor in collapse Length of drill collars required to provide desired WOB including OD, ID and weight per foot. Drill pipe sizes and inspection class The drill string design has to meet the following requirement: The working loads (tension, collapse, burst) on the drill string must not exceed the rated load capacity of each of the drill pipes. The drill collars should be of sufficient length to provide all required WOB to prevent buckling loads on the drill pipe. The drill pipes used have to ensure the availability of sufficient fluid flow rate at the drill bit for hole cleaning and good rate of penetration. 3.2.1 Design Safety Factors Design safety factors are applied to calculated working loads to account for any unexpected service load on the drill string. They are used to represent any features that are not considered in the load calculations e.g. temperature and corrosion, thus ensuring that service loads do not exceed the load capacity of the drill pipe. Design safety factor values are often selected based on experience from operating within a particular area, the extent of uncertainty in the operating conditions e.g. when operating in HPHT conditions, a larger safety factor is applied than when operating in less harsh conditions. Some commonly used design safety values are illustrated in the table below Load Design Safety Factor Value Tension 1.1 1.3 Margin of overpull (MOP) 50,000 100,000. MOP of 400,000 have been used in ultra deep wells Weight on Bit 1.15 or 85% of available Weight on bit to ensure neutral point is 85% of drill collar string length measures from the bottom (API RP 7G) Torsion 1.0 (based on the lesser of the pipe body or tool joint strength) Collapse 1.1 1.15 Burst 1.2 3.2.2 Drill Collar Selection The drill collars are selected with the aim of ensuring that they provide sufficient WOB without buckling or putting the lower section of the drill string in compression. 3.2.2.1 Size selection Lateral movement of the drill bit is controlled by the diameter of the drill collar directly behind it. Therefore the size/diameter of the drill collar closest to the bit will be dependent on the required effective minimum hole diameter and the relationship can be given as When two BHA components of different cross-sectional areas are to be made up, it is essential that the bending resistance ratio (BRR) be evaluated. This is important because BHA components have tensile and compressive forces acting on them when they are bent in the well bore. These forces cause stress at connections and any location where there is a change in cross-sectional area. Therefore it is important to ensure that these stresses are within acceptable ranges. The bending resistance (BR) of a drill string component is dependent on its section modulus which is given as Z = section modulus, in3 I = second moment of area, in4 OD = outside diameter, in ID = inside diameter, in The BRR is used to express any change in BR and can be calculated using BRR should generally be below 5.5 and in severe drilling conditions, below 3.5. 3.2.2.2 Connections When selecting connections to be used with drill collars, it is essential to check that the BRR of the pin and box indicates a balanced connection. The BRR for drill collar connection is calculated as the section modulus of the box divided by the section modulus of the pin. The API RP 7G contains tables that can be used to determine BRR for any box and pin OD. BRRs of 2.5 have given balanced connections (RGU Lecture notes, 2005). 3.2.2.3 Weight on Bit The maximum weight on bit required is normally a function of the bit size and type. The rule of thumb is: Maximum WOB of 2000lbf per inch of bit diameter when using Polycrsyalline Diamond Compact bits (PDC) and mud motors. Maximum WOB of 5000lbf per inch of bit diameter when using tricone bits. Other factors controlling WOB include inclination, hole size and buckling. In vertical wellbores the length of drill collars required to provide a specified weight on bit is given by LDC = Length of Drill Collars, ft WOB = Weight of Bit, lb DFBHA = Safety factor to keep neutral point in drill collars. WDC = Weight per foot of Drill Collars, lb/ft Kb = Buoyancy Factor. The neutral point as described by (Mian, 1991) referring to Lubinksi, is the point that divides the drill stem into two portions, with the section above the neutral point in tension and that below in compression. Therefore in order to ensure that the entire length of drill pipes remain in tension, the neutral point of the drill stem has to be maintained within the drill collars. According to the API RP 7G, the height of the neutral point measured from the bottom of the drill collars will be 85% of the total length of drill collars used, with 85% being the safety factor. In inclined wellbores, the angle of inclination has to be taken into consideration when calculating the maximum WOB that can be applied without buckling the drill pipe. This is because although the WOB is applied at the inclination of the wellbore, this weight acts vertically, thus reducing the available weight at the bit. Therefore to allow for this reduction, the buoyed weight of the BHA would be reduced by the cosine of the well inclination, thus WOB in inclined holes is calculated with the formula All parameters remain as defined in equation 5; ÃŽÂ ¸ is the angle of inclination of the well. As a result of the vertically acting weight of the BHA, the drill string tends to lie on the low side of the hole and is supported to some extent by the wall of the well bore. Therefore the pipes above the neutral point could only buckle if the compressive forces in the drill string exceed a critical amount. This critical buckling force is calculated as follows Fcrit = critical buckling force, lb ODHWDP = outside diameter of HWDP, in. ODtj = maximum outside diameter of pipe, in. IDHWDP = inside diameter of HWDP, in. Kb = buoyancy factor. Dhole = diameter of hole, in. ÃŽËÅ" = hole inclination, degrees. Since HWDP are sometimes used to apply WOB in inclined wells, and drill pipes are sometimes used in compression, the critical buckling force is calculated for both HWDP and drill pipes. 3.2.3 Drill Pipe Selection Factors to be considered for drill pipe selection include: Maximum allowable working loads in tension, collapse, burst, and torsion. Maximum allowable dogleg severity at any depth in order to avoid fatigue damage in the drill pipe. Combined loads on the drill pipe. The loads considered when selecting drill pipes to be used in the drill string is dependent on the well depth, well bore geometry and hole section objectives. In shallower vertical wells, collapse and tension are of more importance than burst or torsion. Burst is normally not considered in most designs since the worst case for a burst load on the drill pipe would occur when pressuring the drillstring with a blocked bit nozzle, even with this condition, the burst resistance of the drill pipe is likely to be exceeded. Torsion is of less importance in vertical well bores because drag forces are at minimal amounts unlike in highly deviated wells. The dogleg severity of the well for both vertical and deviated wells is important because of increased fatigue in the drill pipe when it is rotated in the curved sections of the wellbore. A graphical method is recommended for drill pipe selection, with the loads plotted on a load versus depth graph. This makes it possible for loads at particular points on the drill string to be easily visualised, and any sections of the drill pipe that do not meet the load requirements are easily identified and redesigned. 3.2.3.1 Collapse Drill pipes are sometimes exposed to external pressures which exceed its internal pressures, thereby inducing a collapse load on the drill pipe. The worst scenario for collapse in a drill pipe is during drill stem tests when they are run completely empty into the wellbore. The collapse loads are highest at the bottom joint of the drill pipes, as a result, the collapse load would normally control the drill pipe grade to be used at the bottom of the drill string. The API specified collapse resistance for different sizes and grades of drill pipe assuming either elastic, plastic or transition collapse depending on their diameter to wall thickness ratio have been calculated and are published in the API RP 7G with the relevant formulae. The maximum collapse pressure on the drill pipe when it is completely empty can be calculated as follows: Pc = collapse pressure, psi MW = mud weight, ppg TVD = true vertical depth at which Pc acts, ft. On some occasions, the mud weight outside the pipe varies from that inside the pipe, also the fluid levels inside and outside the pipe may also vary. This situation could also induce collapse loads. The collapse loads induced by this scenario can be calculated thus L = Fluid depth outside the drill pipe, ft MW = Mud weight outside the drill pipe, ppg Y = fluid depth inside drill pipe, ft MW = Mud weight inside drill pipe, ppg. The value for Pc is then plotted on the collapse load graph as the collapse load line see fig 3.5. It is recommended practice to apply a design safety factor to the collapse load calculated from equations 8 or 9 (depending on expected scenarios) in order to account for unexpected additional loads as wells as unknown variables. The value of the design factor is often between 1.1 1.5 for class 2 drill pipes. According to (Adams, 1985) the design factor should be 1.3 to account for the fact that new drill pipes are often not used for drill stem tests. The value of the collapse load multiplied by the collapse design factor is plotted on the collapse load graph as the design line, this is then used to select an appropriate grade and weight of drill pipe to fulfil these load conditions. Fig 3.5: Sample Collapse load graph. 3.2.3.2 Tension Load The tensile load capacity of the drill string should be evaluated to ensure there is enough tensile strength in the topmost joint of each size, weight, grade and class of to support the weight of the drill string submerged in the wellbore, hence the need to include buoyancy in the calculations. There has to also be enough reserve tensile strength to pull the drill string out of the well if the pipe gets stuck. The stabiliser and bit weight can be neglected when calculating the drillstring weight. In a vertical wellbore, the forces acting on the drill string are tension from its self weight and the hydrostatic pressure from the fluid in the wellbore. The hydrostatic pressure in the wellbore exerts an upward force on the cross sectional area of the drill string, which is commonly referred to as buoyancy. Therefore the resulting tensile load on the drill string attached to drill collars, taking account of buoyancy is calculated as: FTEN = resultant tensile load on drill string, lb LDP = length of drill pipe, ft LDC = length of drill collars, ft WTDP = air weight of drill pipe, lb/ft WTDC = air weight of drill collars, lb/ft MW = Mud weight, ppg. ADC = Cross sectional area of drill collars, in2 FTEN is plotted on the tension load graph as the tensile load line. The tensile strength values for different sizes, grades and inspection classes of drill pipes are contained in the API RP 7G, and can be calculated from the equation: Fyield = minimum tensile strength, lb Ym = specified minimum yield stress, psi A = cross section area, in2 Fyield is plotted as the minimum tensile strength line on the tension load graph. However, these values (Fyield) are theoretical values based on minimum areas, wall thickness and yield strength of the drill pipes. Therefore, these values only give an indication of the stress at which a certain total deformation would occur and not the specific point at which permanent deformation of the material begins. If a pipe is loaded to the minimum tensile strength calculated from equation 11, there is the possibility that some permanent stretch may occur, thereby making it difficult to keep the pipe straight in the wellbore. In order to eliminate the possibility of this occurrence, 90% of the minimum tensile strength as recommended by the API (American Petroleum Institute), should be used as the maximum allowable tensile load on the drill pipe, i.e Fdesign = maximum allowable tensile load 0.9 = a constant relating proportional limit to yield strength. Fdesign is plotted on the tension load graph as the maximum allowable tensile load line. As with the collapse load, a design factor would be applied to the tensile loads to account for dynamic loads in the drill pipe which occur when the slips are set, as well as prevent the occurrence of pipe parting close to the surface. The product of FTEN and the design factor is plotted as the tension design load line in the tension load graph see fig 3.6. Margin Of Overpull A margin for overpull is added to the tension load to ensure there is sufficient tensile strength in the drill pipe when it is pulled in the event of a stuck pipe. This margin is normally 50,000 100,000lb, but in deeper wells margins of overpull have reached 300,000lb. The value obtained after adding the margin of overpull is also plotted on the tension load graph see fig 3.6. The difference between the calculated tensile load at any point in the drillstring (FTEN) and the maximum allowable tension load would also represent the available overpull. This value represents available tensile strength of the drill pipe to withstand any extra forces applied to the drill string when trying to release it from a stuck pipe situation. FTEN and Fa can also be expressed as a safety factor This safety factor is an indication of how much the selected drill pipe will be able to withstand expected service loads. Due to uncertainty with actual service loads and conditions, a safety factor greater than 1 is always required. Slip Crush Slip crushing is generally not a problem if the slips are properly maintained. However, it is necessary to apply a safety factor for slip crushing when designing the drill string. This helps account for the hoop stress (SH) caused by the slips and the tensile stress (ST) caused by the weight of the drill string suspended in the slips. This relationship between SH and ST can be represented by the following equation SH = hoop stress, psi ST = tensile stress, psi D = outside diameter of the pipe, in. K = lateral load factor on slips, Ls = length of slips, in. = slip taper usually 9 ° 27 45 z = arctan ÃŽÂ ¼ ÃŽÂ ¼ = coefficient of friction, (approximately 0.08) The calculated tensile load is multiplied by the slip crush factor () to obtain the equivalent tensile load from slip crushing: Ts = tension from slip crushing, lb TL = tension load in drill string, lb SH / ST = slip crush factor. Ts is also plotted on the tension load graph as the slip crush design line. Fig 3.6: Sample Tension load graph The general step-by-step procedure for drill pipe selection using the graphical method is given as 1. Calculate the expected collapse load on drill pipe and apply the collapse design safety factor to derive the design load. Use the result to select weight and grade of drill pipe that satisfy collapse conditions. Plot expected collapse load and design load on a pressure vs. depth graph. 2. Calculate maximum allowable tensile load for the drill pipe selected in (1) above. Also calculate tension load on the drill string including buoyancy effects. Plot the tension load, specified minimum yield strength, and maximum allowable tensile load values on axial load vs. depth graph. 3. Apply tension design factor, margin of overpull, and slip crush factor to the calculated tension load and plot the individual results on the axial load vs. depth graph. Of the three factors applied to the tension load, the one resulting in the highest value is selected as the worst case for tensile loads. 4. Inspect graph and re-design any sections not meeting the load requirements. When designing a tapered drill string, the maximum length of a particular size, weight, grade and class of drill pipes that can be used to drill the selected hole section with specified WOB can be calculated as: All parameters remain as defined in equation 10 and 11. Note that equation 16 is only used when the MOP design line is the worst case scenario for tensile loads. When slip crushing is the worst case, the formula below is used SF = safety factor for slip crushing. The lightest available drill pipe grade should be used first in order to ensure that that the heavier grades are used upper section of the drill string where tensile loads are the highest. 3.2.4 Dog Leg Severity Fatigue damage is the most common type of drill pipe failure. It is known to be caused by cyclic bending loads induced in a drill pipe when it is rotated in the curved sections of the wellbore. The rotation of the drill pipe in the curved hole sections induce stresses in the outer wall of the drill pipe by stretching it and increasing its tensile loads. Fatigue damage from doglegs tends to occur when the angle exceeds a critical value. This critical value can be calculated as: C = maximum permissible dog leg severity, deg/100ft E = Youngs modulus, psi (30 x 106 for steel, 10.5 X 106 for aluminium) D = Drill pipe outer diameter, in. L = half the distance between tool joints, (180 in, for range 2 pipe) T = tension below the dogleg, lb à Ã†â€™b = maximum permissible bending stress, psi. I = drill pipe second moment of area, = à Ã†â€™b, is calculated from the buoyant tensile stress (à Ã†â€™t) and is dependent on the grade of the pipe. à Ã†â€™t = T/A, where T is defined in equation 19, and A is the cross sectional area of the pipe body in in2. For grade E pipe, The results from equation 20 are valid for à Ã†â€™t values up to 67,000psi. For grade S pipe, The results from equation 21 are valid for à Ã†â€™t values up to 133,400psi. It is recommended that an allowable dogleg severity (DLS) versus depth chart be plotted for every hole section with a particular drill string design since DLS changes with depth. The chart is plotted with the DLS on the x-axis and depth on the y-axis (see fig 3.7). When DLS lies to the left of the line or below the curve, the drill pipe is in safe operating conditions, and when it falls above or to the right of the curve, it is in unsafe conditions. Fig 3.7: Allowable Dogleg Severity Chart. (Mian, 1991) 3.2.5 Torsion Drill pipe torsional yield strength is important when planning deviated wells and ultra deep wells. In deviated wells, increased drag forces acting on the drill string from its interaction with the wellbore increase torsional loads on the drill pipe. In deeper wells, it is important in stuck pipe situations, in order to know the maximum torque that can be applied to the drill string. The pipe body torsional yield strength when subjected to torque alone can be calculated from the equation: Q = minimum torsional yield strength, ft lb J = polar second moment of area, à Ã¢â€š ¬/32 (D4 d4) D = pipe OD in, d = pipe ID in. Ym = minimum yield strength, psi. 3.2.6 Combined Loads On The Drill String Collapse and Tension The collapse resistance of the drill pipe is often reduced when the drill pipe is exposed to both tension and collapse loads. This happens because tensile loads stretch the drill pipe thereby affecting its D/t (diameter -wall thickness ratio) which controls the collapse resistance of the drill pipe. In ultra deep wells, the effect of combined collapse and tension is experienced when function testing the Blow out Preventers (BOP). It is becoming common practice in ultradeep drilling to equip BOPs with test rams in order to enable the BOP be tested without setting plugs in the well head. This is done to save tripping time due to extreme well depths. An example given by (Chatar, 2010), using 65/8in 27.70lb/ft drill pipe showed that with 65/8in drill pipe having 860kips of maximum allowable tensile loads, at half of this load, the drill string is only capable of withstanding 4,500psi collapse loads, which is often not sufficient for ultradeep drilling BOPs. The corrected collapse resistance of drill pipes under tension can be calculated using the formula Where R represents the percentage of the collapse resistance left when the drill pipe is under tension, therefore in equation 25, the value for R is used to multiply the normal plastic collapse resistance of the pipe to give the collapse resistance under tension. R can also be determined graphically with the following steps 1. Calculate Z using equation 24 2. Enter the ellipse for biaxial stress (fig 3.8) on the horizontal axis with the value for Z and draw a vertical line to the ellipse curve. 3. Draw a horizontal line from the vertical line drawn in (2) above to the vertical axis and read off the value. 4. Use the value from (5) above to multiply the collapse resistance to get the corrected collapse resistance with tension. Fig 3.8: Ellipse of Biaxial yield Strength: Effect of tensile loading om collapse resistance. (RGU Lecture notes: Casing design) Combined tension and torsion The torsional yield strength of a drill pipe is significantly reduced when the pipe is under tension loads. The torsional yield strength of the drill pipe under tension can be calculated with the equation Q = minimum torsional yield strength under tension, ft lb J = polar second moment of area. D = pipe OD in, d= pipe ID in. Ym = minimum yield strength, psi P = total load in tension, lb A = cross sectional area, in2 3.2.7 Tool Joint Performance The makeup torque to be applied to the tool joints when connecting drill pipes is calculated as follows ID = inside diameter, in. OD = outside diameter, in. Values for X, M, B and Q for standard connections are presented in the table below Type of Connection X

India :: essays research papers

  Ã‚  Ã‚  Ã‚  Ã‚  For more than 200 years before the Indian Mutiny of 1857, there had been a British presence in India. They began as merchant ventures and their holdings on the land were relatively small. Over the years they had expanded, creating forts for protection and larger trading stations. Eventually, to make certain that there would be stability and a successful trade business, Britain deployed many of its armed forces there and also raised forces of natives, thus becoming an active power in 18th Century India. Sometimes by their design but also sometimes by accident, the area of British control began to increase. Their expansion lasted until nearly the entire sub-continent was apart or effected by the empire by the year 1857.   Ã‚  Ã‚  Ã‚  Ã‚  The relationship of the British with their Indian subject gradually began to get worse as time passed. Many held the invention of the steamships responsible for the tension between the two peoples. By allowing the British officers a greatly reduced travel time from their English wives and their workplace, created less time with their Indian mistresses. Another very important aspect was the arrival of missionaries from protestant England. The missionaries cast their teachings upon the very conservative Indians, who preferred their own customs and institutions to other people. Indians especially preferred their own religions and Evangelical Christians had little respect, or understanding of, these ancient practices and beliefs.   Ã‚  Ã‚  Ã‚  Ã‚  The spark that started it happened in May of 1857 with a mutiny of Indian troops at Meerut, or a matter of religious principle. The new rifles, which had been issued by the British army, contained a cartridge that required the soldier to bite of the end in order to load the weapon. To make this process easier, the cartridges were greased with the animal fat of a cow or pig. The rumor quickly spread throughout the Indian regiment that this process was being used, and according to ancient Hindu and Muslim religion, this practice is unclean and according to Lord Roberts, â€Å"the affair betrayed and incredible disregard of the natives’ religious prejudices.†(Porter, 40) The mutineers took Delhi first with the help of more native regiments, and from there, the rebellion spread quickly but unevenly. Throughout the many battles at Delhi, Cawnpore, and Lucknow, the natives were never able to completely seize all of India. Britain did manage to survive the fourteen month long battle, but with severe losses. India :: essays research papers   Ã‚  Ã‚  Ã‚  Ã‚  For more than 200 years before the Indian Mutiny of 1857, there had been a British presence in India. They began as merchant ventures and their holdings on the land were relatively small. Over the years they had expanded, creating forts for protection and larger trading stations. Eventually, to make certain that there would be stability and a successful trade business, Britain deployed many of its armed forces there and also raised forces of natives, thus becoming an active power in 18th Century India. Sometimes by their design but also sometimes by accident, the area of British control began to increase. Their expansion lasted until nearly the entire sub-continent was apart or effected by the empire by the year 1857.   Ã‚  Ã‚  Ã‚  Ã‚  The relationship of the British with their Indian subject gradually began to get worse as time passed. Many held the invention of the steamships responsible for the tension between the two peoples. By allowing the British officers a greatly reduced travel time from their English wives and their workplace, created less time with their Indian mistresses. Another very important aspect was the arrival of missionaries from protestant England. The missionaries cast their teachings upon the very conservative Indians, who preferred their own customs and institutions to other people. Indians especially preferred their own religions and Evangelical Christians had little respect, or understanding of, these ancient practices and beliefs.   Ã‚  Ã‚  Ã‚  Ã‚  The spark that started it happened in May of 1857 with a mutiny of Indian troops at Meerut, or a matter of religious principle. The new rifles, which had been issued by the British army, contained a cartridge that required the soldier to bite of the end in order to load the weapon. To make this process easier, the cartridges were greased with the animal fat of a cow or pig. The rumor quickly spread throughout the Indian regiment that this process was being used, and according to ancient Hindu and Muslim religion, this practice is unclean and according to Lord Roberts, â€Å"the affair betrayed and incredible disregard of the natives’ religious prejudices.†(Porter, 40) The mutineers took Delhi first with the help of more native regiments, and from there, the rebellion spread quickly but unevenly. Throughout the many battles at Delhi, Cawnpore, and Lucknow, the natives were never able to completely seize all of India. Britain did manage to survive the fourteen month long battle, but with severe losses.

Interpreting Dreams Essay -- Freudian, Jungian and Cognitive

Most of us have experienced a dream, be it a nightmare or a pleasant walk in a forest. It was frequently believed that dreams encompass a coded message that might be expressing our hidden wishes, things that happened in the past or even predict the future. In the past, there have been many attempts to unravel the secret hidden behind the dreams and so far the world came up with three main theories of interpreting the dreams (Freudian, Jungian and Cognitive)(Wade, Travis 1998). In this essay I will attempt to analyze my dream by using each of the theories mentioned above, then compare the outcomes as well as their possible connections to my life and in the end determine, which one of these theories is the most accurate and thus as a laic may say the â€Å"best† one. However, I have never believed that my dreams have any meaning and in the course of this analysis I will try to prove that the Cognitive view alone offers the most reasonable explanation of my dreams. My dream had begun on a deserted shore. After a while, I was able to find a little cottage that belonged to a fisherman. I needed from him a boat in order to get to an island (it looked like a great mountain that was rising from the water and was covered with snow). All of a sudden, I sat in the boat with four of my roommates as well as with my father and grandfather. However, only then have we found out that we do not have enough food to get to that island, so we turned our boat back to the harbor. Upon our return, we had gone into a forest that was covering almost all of the land that we were able to see. After a period of time, the length of which I was not able to determine, we have found an arbor and there were many deer running around it. But instead of shooting any of them, I shot an old ugly pig with six bullets. That was the end of my dream. The next day in the morning I wrote it down as soon as I woke up. Sigmund Freud, in his famous book â€Å"Interpretation of Dreams† (1900) presented his new theories about determining the real meaning of our dreams. According to his book, our dreams in their core represent our deepest wishes, desires and instinctual thoughts. However, as these dreams in their original form (latent contents) were unacceptable for our consciousness, the â€Å"censor†(an unconscious mechanism) shaped them into an acceptable and symbolic form (manifest content). These symbols may... ...ne of his lectures: â€Å"The best interpretation (of a dream) is the one that has the greatest logical meaning and is mostly helping you to solve these problems.† (Johnson 2002). From this point of view, the best logical and reasonable explanation of my dream has provided the Cognitive View, which, as it was mentioned in the paragraph above, assumes that all of our dreams are just leftover memories. In my personal opinion it is true, because I was truly able to find in that dream of mine certain aspects that belonged to my past. Of course, I am not claiming that the theories of dream analysis of Sigmund Freud and Carl Jung that worked for decades are wrong, but in my case the outcome of these two theories was too general as well as obscure for me to believe that they represent the best way of dream analysis. Works Cited: Freud, S. (1900). Interpretation of Dreams: NY, New York. Gifford, T. (n.d.). Myths Dreams Symbols. Retrieved October 15th, 2002 from http://www.mythsdreamssymbols.com/ Johnson, M. (2002). Lecture, General Psychology, University of New York / Prague, Prague, Czech Republic. Wade, C. & Travis, C. (1998). Psychology (5th Ed.) New York: Adison Wesley

The Crucible – How does Miller effectively create a sense of tension and conflict between John and Elizabeth Proctor at the beginning of Act two?

Miller effectively creates a sense of tension and conflict between John and Elizabeth Proctor at the beginning of Act two. Act two follows directly on from a very highly charged and climatic note. At the end of act one Abigail and the girls accuse many people in Salem of being witches and a state of hysteria is reached. It is therefore a surprise that act two is not a court scene or trial, merely a domestic scene between John and Elizabeth Proctor. This variation is a good thing I believe as it helps to keep the reader interested and keeps the play from becoming monogamous. This is a very important scene. Miller I believe created this scene and the love interest between Abigail and John Proctor to make the ending of the play far more dramatic. If a significant rift is created between John and Elizabeth, then surely the ending will become more impressive, because as soon as they have conquered their problems and regained trust in each other following John's fight to free Elizabeth, John is hanged. This scene is also important to help us understand Elizabeth's dilemma in act three when Danforth asks her whether John had an affair with Abigail. John is unable to tell her what to say so Elizabeth has to decide for herself whether or not to tell the truth, she is unaware that John has confessed to the affair so denies it happened so as not to incriminate him. Act two helps us to understand that she most definitely did know about the affair and had not forgotten, so therefore is lying to protect John in act three despite their rocky relationship. The audience have already by act two heard only bad words about Elizabeth, so it is likely that they have come to the conclusion that she is not a very nice person. This is due to Abigail bad mouthing Elizabeth and saying that she is â€Å"†¦ a sickly wife† and a â€Å"†¦ cold snivelling woman†. Because we do not meet Elizabeth until later on in the play we only have the opportunity to form an opinion on Elizabeth's character from what Abigail says about her, which is unfortunately all malicious and derogatory. The language used by Miller in the crucible is archaic, rural American. Because the play is based upon events, which took place around 311 years ago, to make it seem realistic it is crucial that miller does use such language. An example of the language used, is when John says to Elizabeth, â€Å"Aye†¦ its warm as blood beneath the clods†, this is definitely not an expression we would use today. Although nowadays we may not understand the language used by Miller perfectly it is important for him to use it in order for the play to become genuine and believable. In his autobiography Timebends, Miller discusses the language he found in the court records. He said that he wanted â€Å"to study the actual words of the interrogations, a gnarled way of speaking† Miller also admitted to unintentionally, â€Å"elaborating a few grammatical forms himself, the double negatives especially†, although Act two is not a court scene I believe that Millers research into the language of the inhabitants of Salem in the 17th Century helped the play to achieve its sense of authenticity. It is important for Miller to create tension within the play to keep the audience interested; he uses this technique in Act two with great affect. The audience is already aware of the Proctors strained relationship following John's affair with Abigail, and Miller highlights the damage that has been done by the affair perfectly in this scene to create a excruciating sense of tension. At the start of Act two Miller using stage directions and has John on his return from the field taste the meal the Elizabeth has been preparing, he is displeased with it so seasons it. This appears at first perfectly normal and harmless to the audience, however when John hears Elizabeth coming downstairs he jumps away from the stove and proceeds to wash his hands. It becomes obvious to the audience at this point that their relationship is so strained that John racked with guilt about his affair with Abigail avoids doing anything at all which might aggravate or offend Elizabeth. This huge effort on John's behalf to not offend Elizabeth is blatant when he tells her that the rabbit is â€Å"well seasoned† Elizabeth gratefully accepts this praise replying that she â€Å"took great care†, this is an awkward scene because both are trying to be friendly to one another but it is easy to see they are uncomfortable in each others presence. It is ironic that John complimented her on the seasoning on the rabbit, since he seasoned it himself; this in particular highlights the conflict between them. At first glance the proctor household appears homely, welcoming and peaceful. John returns home to work and finds his supper ready, cooked for him by his wife who has just finished singing their children to sleep. However this is all very misleading, the conflict between the proctors is highlighted at the very start of act two with the use of monosyllabic sentences from Elizabeth in reply to Johns attempts at conversation. John, full of good intentions, begins to tell Elizabeth about the farm and tries to engage in conversation with her, however she meekly replies to his questions with short, abrupt sentences such as â€Å"That's well†, â€Å"Aye, it would† and â€Å"Aye, it is†. By manipulating the sentence structure Miller is able to show Elizabeth's reluctance to speak to her husband, and highlight the distance and awkwardness present between them. After complimenting Elizabeth on the meal John, talks about the farm and says with a grin â€Å"I mean to please you Elizabeth. And she answers, â€Å"I know it John. † However, before she answers, she pauses, and â€Å"finds it hard to say. † This means that she might not think he honestly wants to please her, or make their marriage work. Since this is quite a dramatic moment, I think that on stage at this moment the lighting should focus on Elizabeth, and if present the orchestra should be silent to emphasize her hesi tation. It becomes very clear in this scene that John is desperately trying to regain Elizabeth's trust. The fact that she is cold and distant towards him creates a great sense of strain and the conflict is plain to see. Miller is able to illustrate this conflict between them by using stage directions, he has John walk over to Elizabeth and kiss her, Elizabeth receives his affection with disappointment, she is still cold and unforgiving. Miller shows us that words are not necessary to convey feelings, the expressions of the actors and their body language is enough and can sometimes be more convincing in a subtle way. When I watched the film made about the play it struck me that in the scene between John and Elizabeth a table had been positioned between them, this acted as a physical barrier. This is actually of great significance and subtly shows the audience that there are obstacles that stand in the way of the proctors, keeping them apart, namely Abigail. Watching the film helped me to see that stage props can be used to great effect, and can often play a significant part in the enhancement of dramatic scenes such as this one. Gradually the tension between the Proctors escalates and soon they are arguing, this is bought about when Elizabeth says â€Å"You came so late I thought you'd gone to Salem this afternoon† to John. We know from the stage directions, which direct the actor's body language that John realises Elizabeth is implying that he went to see Abigail. Miller portrays the tension between them by using exceptionally short sentences that help to show the coldness and curtness that they show towards each other. In this act John and Elizabeth have several blazing arguments and between each argument there is a lull, it becomes apparent that all the personal disagreements and grudges within the town are coming to a head. Like in a crucible, which is a melting pot everything is being brought to the surface and is breaking down, society is collapsing within the town and amongst the town's people. Because Miller builds up several arguments between John and Elizabeth, he prevents this scene from becoming boring and keeps the sense of tension between John and Elizabeth very much alive. Whenever the audience begin to believe that the Proctors have resolved their problems another argument breaks out, this stopping and starting prevents the audience becoming frustrated with the constant squabbling and makes sure the sense of tension and conflict is maintained. The series of smaller outbursts between them then conclude into a huge argument in which Elizabeth says to John † She (Abigail) has an arrow in you yet, John Proctor, and you know it†, this is true, despite the fact that Abigail is in Salem and far away from the Proctors she is still causing arguments between them and is driving a wedge between them. Elizabeth knows that John is still physically attracted to Abigail and that she has a hold on him. She creates a strong sense of conflict because John hates Elizabeth's accusations and resents her for continuing to bring up the past when he simply wants to be forgiven and allowed to have a fresh start and be a good husband to her. It is excruciating to watch this scene between the Proctors and see jealousy, suspicion and mistrust tearing them apart however the tension and conflict created is so strong that the audience feels compelled to watch on. When Hale interrupts the Proctors argument and invades their privacy the sense of conflict between the Proctors eases and the tone of the play and atmosphere changes. John and Elizabeth realise that they must work together to eradicate any suspicions or accusations of them being witches, this causes great tension because it is very hard for them to join forces and act as though nothing between them had happened. Following a huge argument they must help each other and keep up appearances. This is a very subtle and clever way of creating tension. Throughout Act two in the crucible Miller creates a sense of conflict and tension between the Proctors using a number of different methods. Doing this I believe is a brilliant way of keeping the audience interested and making the ending of the book more dramatic. Not only however does this in particular scene help to ensure that the audience wish to watch on, but it also ensures that they understand key events in the play, such as Elizabeth's denial of Johns affair. In act two the audience discover that Elizabeth does know about Johns affair so therefore can work out the later on in the play Elizabeth says that John did not have an affair to protect him, not because she simply did not know. I think that were it not for this scene then the whole of the story would be a lot more complicated and harder to understand. So in conclusion although the tension and sense of conflict that Miller creates between the Proctors make Act two an interesting scene, it also affects the rest of the play and the audiences understanding of events to come as a whole.