A horseshoe magnet

A horseshoe magnet A-1 Horseshoe magnet red silver iron A horseshoe magnet (A-1) has a north and south pole. If a piece of carbon steel contacts both poles, a magnetic circuit is created. In an electromagnetic brake, the north and south pole is created by a coil shell and a wound coil. In a brake, the armature is being pulled against the brake field. (A-3) The frictional contact, which is being controlled by the strength of the magnetic field, is what causes the rotational motion to stop. All of the torque comes from the magnetic attraction and coefficient of friction between the steel of the armature and the steel of the brake field. For many industrial brakes, friction material is used between the poles. The material is mainly used to help decrease the wear rate. But different types of material can also be used to change the coefficient of friction (torque) for special applications. For example, if the brake was required to have an extended time to stop or slip time, a low coefficient material can be used. Conversely, if the brake was r equired to have a slightly higher torque (mostly for low RPM applications), a high coefficient friction material could be used.[1] In a brake, the electromagnetic lines of flux have to attract and pull the armature in contact with it to complete brake engagement. Most industrial applications use what is called a single-flux two-pole brake. The coil shell is made with carbon steel that has a combination of good strength and good magnetic properties. Copper (sometimes aluminum) magnet wire, is used to create the coil, which is held in shell either by a bobbin or by some type of epoxy/adhesive.[2] To help increase life in applications, friction material is used between the poles. This friction material is flush with the steel on the coil shell, since if the friction material was not flush, good magnetic traction could not occur between the faces. Some people look at electromagnetic brakes and mistakenly assume that, since the friction material is flush with the steel, that the brake has already worn down, but this is not the case.[3] [edit] Basic Operation There are three parts to an electrmagnetic brake: field, armature, and hub (which is the input on a brake) (B-2). Usually the magnetic field is bolted to the machine frame (or uses a torque arm that can handle the torque of the brake). So when the armature is attracted to the field the stopping torque is transferred into the field housing and into the machine frame decelerating the load. This can happen very fast (.1-3sec). Disengagement is very simple. Once the field starts to degrade flux falls rapidly and the armature separates. A spring(s) hold the armature away from its corresponding contact surface at a predetermined air gap.[4] V-1 Right hand thumb rule If a piece of copper wire was wound, around the nail and then connected to a battery, it would create an electro magnet. The magnetic field that is generated in the wire, from the current, is known as the right hand thumb rule. (V-1) The strength of the magnetic field can be changed by changing both wire size and the amount of wire (turns). EM clutches are similar; they use a copper wire coil (sometimes aluminum) to create a magnetic field. The fields of EM brakes can be made to operate at almost any DC voltage and the torque produced by the brake will be the same as long as the correct operating voltage and current is used with the correct brake. If a 90 volt brake had 48 volts applied to it, this would get about half of the correct torque output of that brake. This is because voltage/current is almost linear to torque in DC electromagnetic brakes. A constant current power supply is ideal for accurate and maximum torque from a brake. If a non regulated power supply is used the magnetic flux will degrade as the resistance of the coil goes up. Basically, the hotter the coil gets the lower the torque will be produced by about an average of 8% for every 20Â °C. If the temperature is fairly constant, and there is a question of enough service factor in the design for minor temperature fluctuation, by slightly over sizing the brake can compensate for degradation. This will allow the use of a rectified power supply, which is far less expensive than a constant current supply. Based on V = I R, as resistance increases available current falls. An increase in resistance, often results from rising temperature as the coil heats up, according to: Rf = Ri [1 + aCu (Tf Ti)] Where Rf = final resistance, Ri = initial resistance, aCu = copper wires temperature coefficient of resistance, 0.0039 Â °C-1, Tf = final temperature, and Ti = initial temperature. [edit] Engagement Time There are actually two engagement times to consider in an electromagnetic brake. The first one is the time it takes for a coil to develop a magnetic field, strong enough to pull in an armature. Within this, there are two factors to consider. The first one is the amount of ampere turns in a coil, which will determine the strength of a magnetic field. The second one is air gap, which is the space between the armature and the coil shell. Magnetic lines of flux diminish quickly in the air. The further away the attractive piece is from the coil, the longer it will take for that piece to actually develop enough magnetic force to be attracted and pull in to overcome the air gap. For very high cycle applications, floating armatures can be used that rest lightly against the coil shell. In this case, the air gap is zero; but, more importantly the response time is very consistent since there is no air gap to overcome. Air gap is an important consideration especially with a fixed armature design because as the unit wears over many cycles of engagement the armature and the coil shell will create a larger air gap which will change the engagement time of the brakes. In high cycle applications, where registration is important, even the difference of 10 to 15 milliseconds can make a difference, in registration of a machine. Even in a normal cycle application, this is important because a new machine that has accurate timing can eventually see a drift in its accuracy as the machine gets older. The second factor in figuring out response time of a brake is actually much more important than the magnet wire or the air gap. It involves calculating the amount of inertia that the brake needs to decelerate. This is referred to as time to stop. In reality, this is what the end-user is most concerned with. Once it is known how much inertia is present for the brake to stop then the torque can be calculated and the appropriate size of brake can be chosen. Most CAD systems can automatically calculate component inertia, but the key to sizing a brake is calculating how much inertial is reflected back to the brake. To do this, engineers use the formula: T = (WK2 ?N) / (308 t) Where T = required torque in lb-ft, WK2 = total inertia in lb-ft2, ?N = change in the rotational speed in rpm, and t = time during which the acceleration or deceleration must take place. Inertia Calculator There are also online sites that can help confirm how much torque is required to decelerate a given amount of inertia over a specific time. Remember to make sure that the torque chosen, for the brake, should be after the brake has been burnished. [edit] Burnishing What Is It and Why Is It Important? Burnishing is the wearing or mating of opposing surfaces. When the armature and brake faces are produced, the faces are machined as flat as possible. (Some manufacturers also lightly grind the faces to get them smoother.) But even with that the machining process leaves peaks and valleys on the surface of the steel. When a new out of the box brake is initially engaged most peaks on both mating surfaces touch which means that the potential contact area can be significantly reduced. In some cases, an out of box brake may have only 50% of its torque rating. Burnishing is the process of cycling the brake to wear down those initial peaks, so that there is more surface contact between the mating faces Even though burnishing is required to get full torque out of the brake it may not be required in all applications. Simply put, if the application torque is lower than the initial out of box torque of the brake, burnishing would not be required; however, if the torque required is higher, then burnishing needs to be done. In general this tends to be required more on higher torque brakes than on smaller lower torque brakes. The process involves cycling the brake a number of times at a lower inertia, lower speed or a combination of both. Burnishing can require from 20 to over 100 cycles depending upon the size of a brake and the amount of initial torque required. For bearing mounted brakes where the rotor and armature is connected and held in place via a bearing, burnishing does not have to take place on the machine. It can be done individually on a bench or as a group at a burnishing station. Two piece brakes that have separate armatures should try to have the burnishing done on the machine verses a bench. The reason for this is if burnishing on a two piece brake is done on a bench and there is a shift in the mounting tolerance when that brake is mounted to the machine the alignment could be shifted so the burnishing lines on the armature, rotor or brake face may be off slightly preventing that brake from achieving full torque. Again, the difference is only slight so this would only be required in a ver y torque sensitive application. [edit] Torque Burnishing can affect initial torque of a brake but there are also factors that affect the torque performance of a brake in an application. The main one is voltage/current. In the voltage/current section we showed why a constant current supply is important to get full torque out of the brake. When considering torque, the question of using dynamic or static torque for the application is key? For example, if running a machine at relatively low rpm (5 50 depending upon size) there is minimal concern with dynamic torque since the static torque rating of the brake will come closest to where it is running. However, when running a machine at 3,000rpm and applying the brake at its catalog torque, at that rpm, is misleading. Almost all manufacturers put the static rated torque for their brakes in their catalog. So, when trying to determine a specific response rate for a particular brake, the dynamic torque rating is needed. In many cases this can be significantly lower. It can be less than half of the static torque rating. Most manufacturers publish torque curves showing the relationship between dynamic and static torque for a given series of brake. Electromagnetic-Power-Off-Brake Over excitation is used to achieve a faster response time. Its when a coil momentarily receives a higher voltage then its nominal rating. To be effective the over excitation voltage must be significantly, but not to the point of diminishing returns, higher than the normal coil voltage. Three times the voltage typically gives around 1/3 faster response. Fifteen times the normal coil voltage will produce a 3 times faster response time. With over excitation the in rush voltage is momentary. Although it would depend upon the size of the coil the actual time is usually only a few milliseconds. The theory is, for the coil to generate as much of a magnetic field as quickly as possible to attract the armature and start the process of deceleration. Once the over excitation is no longer required the power supply to the brake would return to its normal operating voltage. This process can be repeated a number of times as long as the high voltage does not stay in the coil long enough to cause the coil wire to overheat. [edit] Wear It is very rare that a coil would just stop working in an electromagnetic brake. Typically if a coil fails it is usually due to heat which has caused the insulation of the coil wire to break down. That heat can be caused by high ambient temperature, high cycle rates, slipping or applying too high of a voltage. Most brakes are flanged mounted and have bearings but some brakes are bearing mounted and like the coils, unless bearings are stressed beyond their physical limitations or become contaminated, they tend to have a long life and they are usually the second item to wear out. The main wear in electromagnetic brakes occurs on the faces of the mating surfaces. Every time a brake is engaged during rotation a certain amount of energy is transferred as heat. The transfer, which occurs during rotation, wears both the armature and the opposing contact surface. Based upon the size of the brake, the speed and the inertia, wear rates will differ. With a fixed armature design a brake will eventually simply cease to engage. This is because the air gap will eventually become too large for the magnetic field to overcome. Zero gap or auto wear armatures can wear to the point of less than one half of its original thickness, which will eventually cause missed engagements. [edit] Backlash Some applications require very tight precision between all components. In these applications even a degree of movement between the input and the output when a brake is engaged can be a problem. This is true in many robotic applications. Sometimes the design engineers will order brakes with zero backlash but then key them to the shafts so although the brake will have zero backlash theres still minimal movement occurring between the hub or rotor in the shaft. Most applications, however, do not need true zero backlash and can use a spline type connection. Some of these connections between the armature and the hub are standard splines others are hex or square hub designs. The spline will have the best initial backlash tolerance. Typically less than 2 degrees but the spline and the other connection types can wear over time and the tolerances will increase. [edit] Environment / Contamination As brakes wear they create wear particles. In some applications such as clean rooms or food handling this dust could be a contamination problem so in these applications the brake should be enclosed to prevent the particles from contaminating other surfaces around it. But a more likely scenario is that the brake has a better chance of getting contaminated from its environment. Obviously oil or grease should be kept away from the contact surface because they would significantly reduce the coefficient of friction which could drastically decrease the torque potentially causing failure. Oil midst or lubricated particles can also cause surface contamination. Sometimes paper dust or other contamination can fall in between the contact surfaces. This can also result in a lost of torque. If a known source of contamination is going to be present many clutch manufactures offer contamination shields that prevent material from falling in between the contact surfaces. In brakes that have not been used in a while rust can develop on the surfaces. But in general this is normally not a major concern since the rust is worn off within a few cycles and there is no lasting impact on the torque. [edit] Other Types of Electromagnetic Brakes Electormagnetic Power Off Brake Spring Set Introduction Power off brakes stop or hold a load when electrical power is either accidentally lost or intentionally disconnected. In the past, some companies have referred to these as fail safe brakes. These brakes are typically used on or near an electric motor. Typical applications include robotics, holding brakes for Z axis ball screws and servo motor brakes. Brakes are available in multiple voltages and can have either standard backlash or zero backlash hubs. Multiple disks can also be used to increase brake torque, without increasing brake diameter. There are 2 main types of holding brakes. The first is spring applied brakes. The second is permanent magnet brakes. How It Works Spring Type When no electricity is applied to the brake, a spring pushes against a pressure plate, squeezing the friction disk between the inner pressure plate and the outer cover plate. This frictional clamping force is transferred to the hub, which is mounted to a shaft. Permanent Magnet Type A permanent magnet holding brake looks very similar to a standard power applied electromagnetic brake. Instead of squeezing a friction disk, via springs, it uses permanent magnets to attract a single face armature. When the brake is engaged, the permanent magnets create magnetic lines of flux, which can turn attract the armature to the brake housing. To disengage the brake, power is applied to the coil which sets up an alternate magnetic field that cancels out the magnetic flux of the permanent magnets. Both power off brakes are considered to be engaged when no power is applied to them. They are typically required to hold or to stop alone in the event of a loss of power or when power is not available in a machine circuit. Permanent magnet brakes have a very high torque for their size, but also require a constant current control to offset the permanent magnetic field. Spring applied brakes do not require a constant current control, they can use a simple rectifier, but are larger in diameter or would need stacked friction disks to increase the torque. [edit] Electromagnetic Particle Brake Magnetic Particle Brake Introduction Magnetic particle brakes are unique in their design from other electro-mechanical brakes because of the wide operating torque range available. Like an electro-mechanical brake, torque to voltage is almost linear; however, in a magnetic particle brake, torque can be controlled very accurately (within the operating RPM range of the unit). This makes these units ideally suited for tension control applications, such as wire winding, foil, film, and tape tension control. Because of their fast response, they can also be used in high cycle applications, such as magnetic card readers, sorting machines and labeling equipment. How It Works Magnetic particles (very similar to iron filings) are located in the powder cavity. When electricity is applied to the coil, the resulting magnetic flux tries to bind the particles together, almost like a magnetic particle slush. As the electric current is increased, the binding of the particles becomes stronger. The brake rotor passes through these bound particles. The output of the housing is rigidly attached to some portion of the machine. As the particles start to bind together, a resistant force is created on the rotor, slowing, and eventually stopping the output shaft. When electricity is removed from the brake, the input is free to turn with the shaft. Since magnetic particle powder is in the cavity, all magnetic particle units have some type of minimum drag associated with them. [edit] Electromagnetic Hysteresis Power Brake Electomagnetic Hysteresis Power Brake Introduction Electrical hysteresis units have an extremely wide torque range. Since these units can be controlled remotely, they are ideal for test stand applications where varying torque is required. Since drag torque is minimal, these units offer the widest available torque range of any of the hysteresis products. Most applications involving powered hysteresis units are in test stand requirements. How It Works When electricity is applied to the field, it creates an internal magnetic flux. That flux is then transferred into a hysteresis disk passing through the field. The hysteresis disk is attached to the brake shaft. A magnetic drag on the hysteresis disk allows for a constant drag, or eventual stoppage of the output shaft. When electricity is removed from the brake, the hysteresis disk is free to turn, and no relative force is transmitted between either member. Therefore, the only torque seen between the input and the output is bearing drag. [edit] Multiple Disk Brakes Electromagnetic Multiple Disk Brake Introduction Multiple disk brakes are used to deliver extremely high torque within a small space. These brakes can be used either wet or dry, which makes them ideal to run in multi speed gear box applications, machine tool applications, or in off road equipment. How It Works Electro-mechanical disk brakes operate via electrical actuation, but transmit torque mechanically. When electricity is applied to the coil of an electromagnet, the magnetic flux attracts the armature to the face of the brake. As it does so, it squeezes the inner and outer friction disks together. The hub is normally mounted on the shaft that is rotating. The brake housing is mounted solidly to the machine frame. As the disks are squeezed, torque is transmitted from the hub into the machine frame, stopping and holding the shaft. When electricity is removed from the brake, the armature is free to turn with the shaft. Springs keep the friction disk and armature away from each other. There is no contact between breaking surfaces and minimal drag. Architecture of an Electromechanical Braking System General architecture of an electromechanical braking (EMB) system in a drive-by-wire car is shown in Fig. 1. The system mainly comprises five types of elements: Processors including an Electronic Control Unit (ECU) and other local processors Memory (mainly integrated into the ECU) Sensors Actuators Communication network(s). Once the driver inputs a brake command to the system via a human-machine interface HMI (e.g. the brake pedal), four independent brake commands are generated by the ECU based on high level brake functions such as anti-lock braking system (ABS) or vehicle stability control (VSC). These command signals are sent to the four electric calipers (e-calipers) via a communication network. As this network might not be able to properly communicate with the e-calipers due to network faults, HMI sensory data are also directly transmitted to each e-caliper via a separate data bus. In each e-caliper a controller uses the brake command (received from ECU) as a reference input. The controller provides drive control commands for a power control module. This module controls three phase drive currents for the brake actuator which is a permanent magnet DC motor, energised by 42V sources. In addition to tracking its reference brake command, the caliper controller also controls the position and speed of the brake actuator. Thus, two sensors are vitally required to measure the position and speed of the actuator in each e-caliper. Because of the safety critical nature of the application, even missing a limited number of samples of these sensory data should be compensated for. [edit] Voting A brake-by-wire system, by nature, is a safety critical system and therefore fault tolerance is a vitally important characteristic of this system. As a result, a brake-by-wire system is designed in such way that many of its essential information would be derived from a variety of sources (sensors) and be handled by more than the bare necessity hardware. Three main types of redundancy usually exist in a brake-by-wire system: Redundant sensors in safety critical components such as the brake pedal. Redundant copies of some signals that are of particular safety importance such as displacement and force measurements of the brake pedal copied by multiple processors in the pedal interface unit. Redundant hardware to perform important processing tasks such as multiple processors for the electronic control unit (ECU) in Fig. 1. In order to utilize the existing redundancy, voting algorithms need to be evaluated, modified and adopted to meet the stringent requirements of a brake-by-wire system. Reliability, fault tolerance and accuracy are the main targeted outcomes of the voting techniques that should be developed especially for redundancy resolution inside a brake-by-wire system. Example of a solution for this problem: A fuzzy voter developed to fuse the information provided by three sensors devised in a brake pedal design. [edit] Missing data compensation In a by-wire car, some sensors are safety-critical components, and their failure will disrupt the vehicle function and endanger human lives. Two examples are the brake pedal sensors and the wheel speed sensors. The electronic control unit must always be informed of the drivers intentions to brake or to stop the vehicle. Therefore, missing the pedal sensor data is a serious problem for functionality of the vehicle control system. Wheel speed data are also vital in a brake-by-wire system to avoid skidding. The design of a by-wire car should provide safeguards against missing some of the data samples provided by the safety-critical sensors. Popular solutions are to provide redundant sensors and to apply a fail-safe mechanism. In addition to a complete sensor loss, the electronic control unit may also suffer an intermittent (temporary) data loss. For example, sensor data can sometimes fail to reach the electronic control unit. This may happen due to a temporary problem with the sensor it self or with the data transmission path. It may also result from an instantaneous short circuit or disconnection, a communication network fault, or a sudden increase in noise. In such cases, for a safe operation, the system has to be compensated for missing data samples. Example of a solution for this problem: Missing data compensation by a predictive filter. [edit] Accurate estimation of position and speed of brake actuators in the e-calipers The caliper controller controls the position and speed of the brake actuator (besides its main task which is tracking of its reference brake command). Thus, position and speed sensors are vitally required in each e-caliper and an efficient design of a measurement mechanism to sense the position and speed of the actuator is required. Recent designs for brake-by-wire systems use resolvers to provide accurate and continuous measurements for both absolute position and speed of the rotor of the actuators. Incremental encoders are relative position sensors and their additive error needs to be calibrated or compensated for by different methods. Unlike the encoders, resolvers provide two output signals that always allow the detection of absolute angular position. In addition, they suppress common mode noise and are especially useful in a noisy environment. Because of these reasons, resolvers are usually applied for the purpose of position and speed measurement in brake-by-wire systems. Howev er, nonlinear and robust observers are required to extract accurate position and speed estimates from the sinusoidal signals provided by resolvers. Example of a solution for this problem: A hybrid resolver-to-digital conversion scheme with guaranteed robust stability and automatic calibration of the resolvers used in an EMB system. [edit] Measurement and/or estimation of clamp force in the electromechanical calipers A clamp force sensor is a relatively expensive component in an EMB caliper. The cost is derived from its high unit value from a supplier, as well as marked production expenses because of its inclusion. The later emanates from the complex assembly procedures dealing with small tolerances, as well as on-line calibration for performance variability from one clamp force sensor to another. The successful use of a clamp force sensor in an EMB system poses a challenging engineering task. If a clamp force sensor is placed close to a brake pad, then it will be subjected to severe temperature conditions reaching up to 800 degrees Celsius that will challenge its mechanical integrity. Also temperature drifts must be compensated for. This situation can be avoided by embedding a clamp force sensor deep within the caliper. However, embedding this sensor leads to hysteresis that is influenced by friction between the clamp force sensor and the point of contact of an inner pad with the rotor. This hys teresis prevents a true clamp force to be measured. Due to the cost issues and engineering challenges involved with including the clamp force sensor, it might be desirable to eliminate this component from the EMB system. A potential opportunity to achieve this presents itself in accurate estimation of the clamp force based on alternative EMB system sensory measurements leading to the omission of a clamp force sensor. Example of a solution for this problem: Clamp force estimation from actuator position and current measurements using sensor data fusion. A magnetometer is a scientific instrument used to measure the strength and/or direction of the magnetic field in the vicinity of the instrument. Magnetism varies from place to place and differences in Earths magnetic field (the magnetosphere) can be caused by the differing nature of rocks and the interaction between charged particles from the Sun and the magnetosphere of a planet. Magnetometers are often a frequent component instrument on spacecraft that explore planets. [edit] Uses Magnetometers are used in ground-based electromagnetic geophysical surveys (such as magnetotellurics) to assist with detecting mineralization and corresponding geological structures. Airborne geophysical surveys use magnetometers that can detect magnetic field variations caused by mineralization, using airplanes like the Shrike Commander.[1] Magnetometers are also used to detect archaeological sites, shipwrecks and other buried or submerged objects, and in metal detectors to detect metal objects, such as guns in security screening. Magnetic anomaly detectors detect submarines for military purposes. They are used in directional drilling for oil or gas to detect the azimuth of the drilling tools near the drill bit. They are most often paired up with accelerometers in drilling tools so that both the inclination and azimuth of the drill bit can be found. Magnetometers are very sensitive, and can give an indication of possible auroral activity before one can see the light from the aurora. A grid of magnetometers around the world constantly measures the effect of the solar wind on the Earths magnetic field, which is published on the K-index.[2] A three-axis fluxgate magnetometer was part of the Mariner 2 and Mariner 10 missions.[3] A dual technique Magnetometer is part of the Cassini-Huygens mission to explore Saturn.[4] This system is composed of a vector helium and fluxgate magnetometers.[5] Magnetometers are also a component instrument on the Mercury MESSENGER mission. A magnetometer can also be used by satellites like GOES to measure both the magnitude and direction of a planets or moons magnetic field. Further information: Spacecraft magnetometer [edit] Mobile phones Magnetometers are appearing in mobile phones. The Apple iPhone 3GS has a magnetometer and comes with a compass app for showing direction. It can also reorient maps to show the direction youre facing.[6] [edit] Types Magnetometers can be divided into two basic types: Scalar magnetometers measure the total strength of the magnetic field to which they are subjected, and Vector magnetometers have the capability to measure the component of the magnetic field in a particular direction, relative to the spatial orientation of the device. The use of three orthogonal vector magnetometers allows the magnetic field strength, inclination and declination to be uniquely defined. Examples of vector magnetometers are fluxgates, superconducting quantum interference devices (SQUIDs), and the atomic SERF magnetometer. Some scalar magnetometers are discuss

Women Coping with Breast Cancer Essay -- Health, Diseases, Cancer Diag

Women Coping with Breast Cancer Coping has been closely connected to stress; it involves a process by which a person attempts to restore balance in response to a stressful life event (Henderson, Gore, Davis, and Condon, 2003). The most common cancer among Canadian women in 2010 is breast cancer. An average of 445 Canadian women will be diagnosed with breast cancer and an average of 100 Canadian women will die of breast cancer every week (Canadian Cancer Society, 2010). Coping with breast cancer has been defined as being emotionally and physically challenging for women and their families (Henderson et Al., 2003). Women that are newly diagnosed with breast cancer and those in the period between diagnosis and treatment are seen as being most stressful due to the uncertainty and ambiguity about the disease, lack of information and the need to make treatment decisions as soon as possible (Balneaves and Long, 1999). Understanding women’s experience in coping with breast cancer will aid nurses and other health car e professionals to recognize maladaptive coping strategies and ensure that women receive the support that they need in order to promote physical and psychological recovery (Luker, Beaver, Leinster and Owens, 1996). Description of Literature The purpose of this limited descriptive review is to develop an understanding of how women cope when diagnosed with breast cancer. The review includes 13 single studies in total, represented by seven quantitative studies and six qualitative studies from 1996-2008. In addition, one mixed-method study will be reviewed. The chosen articles will be defined according to paradigm, method, samples, and key findings. Also, it will be described in a synthesized manner according to qualitative and... ... 2006; Gonzalez and Lengacher, 2007). Another limitation that was noted among the literature was the potential bias in selecting samples and the generalization of the studies findings was limited. The data needs to be considered because of the complex nature of the disease and treatments (Wengstrom et al., 2001; Ebright and Lyon, 2002; Henderson et al., 2003; Carlsson, 2005; Li and Lambert, 2007; Gonzalez and Lengacher, 2007). Lastly, in a number of studies, the data was only measure at one point in time. Feelings and emotions change from time to time. Also, a single time measurement does not allow dynamic changes in the study to be investigated accordingly. Measuring multiple times will aid in providing more credible data for the studies (Luker, et al., 1996; Henderson et al, 2003; Gelinas and Fillion, 2004; Drageset and Lindstrom, 2005; Carlsson et al., 2005).

Heathcliff as Byronic Hero of Emily Brontes Wuthering Heights Essay

Heathcliff as Byronic Hero of Wuthering Heights      Ã‚   It is difficult if not impossible to find a character in Emily Bronte's Wuthering Heights that is 100% convincing as the hero -- until one applies the qualities of the Byronic hero.   Ã‚  Ã‚     Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   When considering Wuthering Heights Heathcliff immediately jumps to mind as the villainous character.   Upon his return he wickedly orchestrates Hindley's economic demise and takes control of the Heights.   He attempts to win Catherine, now a married woman, back and when that fails takes in marriage Isabelle Linton, Edgar's sister, with the sole intention of torturing her as a way of avenging himself on Edgar for marrying the woman he loved.   When Hindley died Heathcliff took his son, Hareton, in order to treat him as cruelly as Hindley had treated Heathcliff, thus taking his revenge on Hindley.   To further punish Edgar, Heathcliff kidnaps Cathy, forces her to marry his son, Linton, and in so doing gains possession of Thruschcross Grange and has the authority to treat Cathy as he desires.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Heathcliff obviously has a nasty vengeful side but that makes his character perfect to bear the mantle of the Byronic hero.  Ã‚   He rebels against the social order in his world by attempting to defy Hindley and associate with Catherine and later in his attempt to woo her from Edgar's arms and home and make her his own.   He is very definitely self-destructive and cares for no one but himself and Catherine, which at times seem debatable.   His passion in life is not life but to avenge himself upon everyone that has ever slighted him.   He systematically destroys the lives of the people who hurt him but he refuses to stop there - insisting upon further punishing those individuals through... ...nder the earth until he can join her in death so that he need not endure a single day without the knowledge of her close by.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   All of Heathcliff's actions sprung from his desire to be with Catherine.   When he was denied this, primarily because of his social standing and background, he sets about to ruin the lives of those who assume they are better than he because of their position in society.   Heathcliff cannot be categorized a villain but rather is dubbed Byronic Hero and to some extent, the victim of a spoiled manipulative brat.    Works Cited Damrosch, David, et al., ed.   The Longman Anthology of British Literature: Vol. B.   Compact ed.   New York: Longman - Addison Wesley Longman, 2000. Bronte, Emily.   Wuthering Heights. Norton Critical ed.   3rd ed.   Ed. William M. Sale, Jr., and Richard J. Dunn.   New York:   W. W. Norton, 1990.   

A Mountain Run :: Exploratory Essays Research Papers

A run to the top of a mountain can be understood in terms of numerous practical figures: 1407 feet in elevation; 2.5 miles (4 km) of trail; 2.4 foot strides that shorten as the trail steepens; 110 pounds of body weight striking the ground in two-month-old (400 miles of summer training) GT-2020 Asics running shoes; 18 minutes and 17 seconds clocked on an 8-lap memory, digital Triathlon Timex; a 420-calorie breakfast (a bowl of cereal, half a bagel, and a banana) eaten three hours earlier; muscle cells using the glycogen stores from this food and incorporating the free fatty acids in the blood for energy; muscles in need of oxygen utilizing chemical processes that free oxygen from within the muscle itself; wastes building up in the muscles faster than the blood can remove them. These physiological, mathematical, and anecdotal elements are, however, some of the furthest from my realm of consciousness as I approach my ascent. Jogging on the Point Reyes Peninsula’s Bear Valley Trai l, I come to the head of the Sky Trail, a trail that climbs up Mt. Wittenberg, a mild but memorable little mountain in the National Seashore. Beginning this run up a mountain feels somewhat like starting a race. Throughout the eight years I have run competitively, I have never felt completely comfortable with the fact that I choose to stand, leaning forward on a line while nervously holding my breath, waiting for some gun to announce the start of a completely uncomfortable journey. There are plenty of reasons not to begin a race, and there are many more reasons not to run up this particular mountain. Deliberations, however, are more agonizing than the run itself. Although this morning’s run lacks all of the hype of a big race, I can’t help feeling now the same as I would then: just let the movement begin. In his novel, Once a Runner,John L. Parker’s character, Cassidy, envisions the start of a race with the urgency most runners share: â€Å"The all-consuming roar, the overwhelming psych would begin then and would build up until he stood ready on this line, at once controlled and near lunacy, fear less and terrified, wishing for the relief of the start, the misery of the end. Anything! Just let the waiting be done with!†1 Although numerous haunting â€Å"why’s† are tempting dissuasions before any unnecessary physical exertion, I cannot bear to ponder them all at the base of this mountain.

On the Necessity of Rationalism

In the process of considering the various means of justification, a relativistic conception of reality assumes that the truth and hence the validity of a statement may only be assessed in relation to the perspective of the discipline which holds a particular belief. In this sense, truth is dependent upon the internal coherence of beliefs within a system of thought. In his The Last Word, Nagel claims that such is not the case. He argues that the truth and hence the validity of statements are dependent upon an unqualified notion of reason.He claims that the truth of a statement is independent upon any particular perspective. If such is the case, it follows that the truth of any statement is independent from the schema [truth schema] presented by any system of thought. In relation to scientific claims, it thereby follows that the truth of scientific claims ought to be assessed through the unqualified notion of reason as opposed to merely their internal coherence within the scientific co nception of reality [scientific framework].The aforementioned argument is based upon the critique of the intrinsic limits to subjectivist doubt since challenges to the independent validity of reason must themselves assume the independent validity of reason. Any explanation of reason deriving from outside the mind can itself be explained only from inside the mind, as having its own independent validity. In the case of scientific knowledge, he argues that it is mistaken to assume that the scientific discipline has freed itself from the limits of the Cartesian problem through the replacement of judgments about rules of practice from objective judgments.Nagel argues that if science will continually adhere to a subjectivistic and hence relativistic framework, the discipline will fail to provide an objective account of reality. He claims, â€Å"the general aim of such reasoning [scientific reasoning] is to make sense of the world in which we find ourselves and how it appears to us and ot hers† (81). If such is the case, it is necessary to conceive of the conception of the world which is not based upon an a priori conception of reality dependent upon a preconceived and limited conception of the word. According to Nagel, such an account is not provided by science.The reasons for this lies in the subjectivism of science (Nagel 84). Subjectivism within science [scientific methods] is apparent if one considers that the scientific â€Å"demand for order cannot itself be rationally justified nor does it correspond to a self-evident necessity† (Nagel 84). He notes that scientific subjectivism can only end if it adheres to rational means of knowledge acquisition. It is only through the defense of rationalism that an objectivist account of evidence is possible.Nagel further argues that the appeal of subjectivism arises out of a certain reductionist impulse in modern explanation as this reductionist impulse enables the explanation of things to hinge on their reduc tion to local and finite terms thereby ensuring subjectivist conclusions. Although this enables the assurance against rationalist explanations that refuse to make reason into something irrational or that conceive of reason as a capacity for grasping the universal and infinite principle, the reductionist explanation is in itself dependent on an irreducibly nonlocal and objective understanding of reason. Nagel argues that doubt about reason presupposes reason’s independent validity hence reason’s independent validity cannot be coherently doubted.He rightly argues that to object to reason on the grounds we cannot strictly explain it in naturalistic terms is to misunderstand the irreducible nature of the concept since reason cannot be so explained without losing its meaning or validity and that, as such, it is justified in a different way, by showing it to be necessary to intelligible thought and action. Science thereby must opt for a rationalistic as opposed to a subjecti vistic account of reality for it to maintain its value as a discipline.Work CitedNagel, Thomas. The Last Word. New York: Oxford University Press, 1997.Essay Number TwoEdmund Gettier’s Counterargument Against thePlatonic Tripartite Account of Propositional KnowledgeThe Platonic tripartite definition of propositional and fallibilist knowledge found in the last section of the Theaetetus states that knowledge of P occurs when an epistemic agent S knows that P if and only if (1) P is true, (2) S believes that P, and (3) S is justified in believing that P (90). A well-known opposition to such an account of propositional knowledge questions the sufficiency of the aforementioned conditions.It is argued that although the aforementioned conditions are necessary in the definition of propositional knowledge such conditions are insufficient due to their failure to ensure S against conditions wherein knowledge of P occurs as a result of mere epistemic luck (Gettier 123). This critique is b est known as the Gettier type counter examples towards the tripartite definition of propositional knowledge mentioned above.A logical problem is posited by the Gettier type counter examples. This logical problem is evident in the lack of successful coordination between the truth of P and the reasons that justify S in holding P. Floridi notes that Gettier type counter examples arise â€Å"because the truth and the justification of P happen to be not only independent but also opaquely unrelated that they happen to fail to converge or agree on the same propositional content P†¦without S realizing it† (64). In order to understand this, it is important to lay down the main assumptions of Gettier’s counter argument that seeks to explicate the aforementioned logical problem.Gettier’s argument against the tripartite account of propositional knowledge, which involves the conception of knowledge as justified true belief arose as a result of the following claim: knowl edge [propositional knowledge] does not merely involve justified true belief. Such a claim is based upon the following assumptions. First, there are instances wherein the warrant is not a sufficient condition for a belief in P. This is evident if one considers that instances of belief and knowledge of P are in some respects epistemically different [other than in terms of truth] from belief of P without knowledge of P. Second, there are instances wherein warrant is fallible.This is due to the insufficiency of truth and justification as warrants for knowledge. The evidence of such, according to Gettier is apparent if one considers that it is possible for P to be false even if S believes that P possesses epistemically significant properties such that whenever a belief possesses such properties and is true the belief may thereby qualify as knowledge. Lastly, there is the closure of knowledge under obvious and known entailments. The last assumption argues that if S is justified in believ ing P and a deductively valid inference is drawn from P to another belief Q then S is justified in believing Q. This is a result of the entailment of Q from P.From what was stated above, it is possible to present the usual form of Gettier’s attack against the tripartite account of knowledge. Gettier’s counter argument is based upon the critique of warrant, fallibility, and closure. Note that combination of the three claims mentioned above leads to a contradiction. From what was mentioned above it follows that it is possible to believe in an obvious deductive consequence of P, which is Q, while in the process retaining the epistemically significant properties of the belief in P.If such is the case, it is possible to have a justified true belief of any property which has led S to have a belief in Q or any other type of belief which has Q’s epistemic characteristics. Note that this contradicts the assumed necessity that P and Q differ from each other since one qual ifies as knowledge [S believes and has knowledge of P] whereas Q merely qualifies as a belief [S believes but does not have knowledge of Q].Works CitedFloridi, L. â€Å"On the Logical Unsolvability of the Gettier Problem.† Synthese 142(2004): 61-79.Gettier, E. â€Å"Is Justified True Belief Knowledge?† Analysis 23(1963): 121-23.Plato. Theaetetus. Trans. M.J. Levett. Indiana: Hackett Publishing Co., 1992.

The Policy Process Part Iii

The Policy Process, spell II University of Phoenix HCS 455 The Policy Process, expose II In the musical composition the power discussed The Policy Process, start a room I on how Medic ar part D became a insurance policy. The agent discussed the details on the somaulation, legislative, and murder s tailes of the policy. instantaneously time to air at the concluding stages of the military operation, of Medicargon break apart D. Which be evaluation, analysis, modification, and methodology stages. In every policy there exit be an evaluation stage to forecast how the policy provide work and what c every(prenominal) for to be through with(p) to respect the process. valuation poseThe evaluation stage is a process in which policymakers in the Senate and House look at a policy and pass judgment the future outcomes of a policy in this case Medicare startle D. For compositors case at once of the evaluation process would be how policymakers would evaluate the pharma ceutical companies to make sure to corroborate prescription costs down. An other(a) would be to evaluate how m any(prenominal) of age(p) citizens are enrolling in the devise. As thoroughly as making sure old citizens take on either told the breeding available to them to prefer the correct intention that fits their prescription leases. For instance the Kaiser Foundation did a study on the technical problems of Medicare dampen D.One of Kaisers receiveings dep peculiarityn confusedness on which prescriptions would be covered from the numerous plans that an individual flock train from. As well, as medical providers not get the new medical software to passing Medicare come apart D into their reckoner systems. This meant that deflection agencies like, doctors, insurance companies, and pharmacies run different programs and that shit different policies on how to entirelyot perseverings cultivation. Now on the other hand, if all these agencies can play in the id entical software this would allow everyone in the forbearings medical circle to share the same codes and computer language.Thus, not having to set a great deal of usual pain and confusion nearly the patients medicate reportings. other problem was transferring large patients files from one investment banker to another insurer can take up to sextuplet months, from a 2004 study from the Medicare Payment consultative Commission(Terri Emerick, 2006). One of the solutions to these problems would be to evaluate the development which is being sent to ranking(prenominal) citizens. Medicare should lance out their booklet to all elder citizens that are in the do drugs plan. whole senior citizens should write down their musics which they are taking. many another(prenominal) an(prenominal) seniors that do go to their local senior centers should go online and check out the Medicare website for tuition. As well calling Medicare to ask questions some(prenominal)what which plan go forth work crush for them. Do not forget to let loose to your local pharmacist he or she might be able to enounce the names of the plans which cover the prescriptions. By evaluating these areas policymakers can get selective information from outside agencies to do research and come up with results from polls, interviews, and surveys. In evaluating all this information policymakers can form an analysis of Medicare burst D and advert what pick up to be done.Analysis Stage Analyzing Medicare transgress D as the author express earlier one of the problems where the technical problems amid the different agencies and sharing patients information. On February 17, 2009 chairman Obama signed a $787 gazillion dollar sign arousal bill which puts $150 billion dollars on spending health information technology (Omini MD, 2009). This new plan physicians and health nonrecreationals go a modality now receive incentives for implementing IT programs into their computer systems. Be coming paperless will maximize Medicare as well as physicians and medical professionals.By 2015 it will be mandatory that all physicians and medical professionals use IT programs. The United States Department of wellness and Human Services (HHS) by declination 31, 2009 under the stimulation act will develop a set of standards, implementation methods, and criteria for the new IT system to be in lieu (Chris genus Silvia, 2009). Another analysis was make about the ad on the dotment flow. The enrollment point in time to enroll in a drug coverage plan is from November fifteenth by means of declination 3 beginning(a). Many venerable individuals felt they were getting rushed into signing up for a plan.Most of them were confused and explaining why they essential preference a new drug coverage program every socio-economic class. Many individuals fail to sign up inwardly the six week time dust due to their medical or intellectual condition. This is something that would need t o be analyzed and see if they can extend the enrollment period from six week to 12 weeks. prick the enrollment period on October 1st instead of November 15th. This would give many elderly individuals plenty enough time to pick, choose, and change plans before the declination 31st end date.In this entire analysis one must think there should be revisions do to the policy to make it develop. Revision Stage In revising a policy starts by looking to see which policies need to be updated or changed to make the policy better. On September 5, 2008 one of the revisions in Medicare Part D was the use of electronic Prescription Program (E-prescribing) Centers for Medicare and Medicaid Services (CMS) expects that Medicare Part D sponsors will have all the necessary contracts and systems in place should prescribers liking to use E-prescribing (Claudia Schlosberg, n. . ) As stated in the paragraph above with IT systems for physicians and health professionals development paperless system w ill maximize Medicare. This revision will not only helper out pharmacies but help out physicians. Now this information will allows doctors to find out what prescriptions the patient has used in the past and where the patient usually goes to pick up his or her medications from. By revising this policy everyone in the medical community can deliver faster and better care for the individual.Since many senior citizens bear on to do work, due to their low income, CMS has rewrite a section on Medicare Part D for employers. Employers whom are offering medication drug coverages to Medicare individuals will now disclose to CMS if the plans the employer is offering are creditable. To make sure that the prescription drug plans are creditable, the plans must equal or exceed the actuarial value of be standard prescription drug coverage under CMS guidelines (Kutak vibrate, 2007).This revision in Medicare Part D is very important for seniors, this way seniors can know if the program that they have from work is creditable and make a decision on whether or not he or she should waive the enrollment of Medicare Part D. They employer must submit to CMS all the prescription drug plans that they offer to see if the plans follow CMS guidelines. Employers must also conduct out information to those individuals in the plan on or before the Medicare Part D enrollment date of November 15th of each year. Purpose and MethodologiesOne of the methodologies in Medicare Part D was to make sure senior citizens get help with their drug prescription costs. Even thou CMS has many plans to choose from seniors need to do their part in researching some of the plans via internet, CMS hotline, and talking to their pharmacist. In scrap the E-prescribing was another to help physicians and pharmacies to collect information more quickly without using any paper. By having everything computerized pharmacists can receive and gather information quickly compared to the old employ of using a fax machine. Using a computer eliminates misplaced fax paper, paper jams, or the fax did not go through. This saves time and property on some(prenominal) parts for the physician and pharmacists. IT software remark pile the president Obama signed this year to help all healthcare professions to go paperless and receive patients information more quickly than before. This as well will save time and money for healthcare professionals in managing patients data to make sure all parties involved get the information they need for billing and medical information.So these are just some of the purposes and methodologies for some changes in the Medicare Part D. Conclusion As more senior citizens coming into retirement Medicare Part D will be a major(ip) focus of discussion on the political front. Both Democrats and Republicans have different ideas on how to evaluate, analyze, and revise Medicare Part D. Of course, from the authors perspective having IT software programs in place will help out then for al l healthcare professionals and providers. Now with the Obama stimulus plan sign this year hopefully, all healthcare professions can be on the same track to get these IT systems in place.The benefits are enormous to getting information faster to the right people, especially in an emergency. Although CMS needs to do a better job on informing seniors about the prescription drug plans, so that way they can make better judgments on the plan they choose. Even better unless cut down on some of these plans these are way too many of them and they are confusing seniors on which plan to choose from. Either way policymakers from twain sides need to work with healthcare professional to see what can be done to improve on Medicare Part D. References Chris Silvia (2009).Practices paperless before 2012 could maximize Medicare bonuses. Retrieved December 2, 2011, from http//www. ama-assn. org/amednews/2009/03/16/gvsa0316. htm Claudia Schlosberg (n. d. ). CMS Revises Medicare Prescription Drug Benef it Manuel-Chapter 7 Medication Therapy Management and Quality progression Program. Retrieved December 2, 2011, from http//www. ascp. com/advocacy/upload/ASCP%20Summary%20of %20CMS%20Chap%207%20Revisions. pdf Kutak Rock (2007). Medicare Part D CMS Revises Model chance on and Disclosure Notice Requirements. Retrieved December 2, 2011, from http//www. utakrock. com/publications/employeebenefits/EBCA1107. pdf Omini MD (2011). Medicaid, health IT to see billions from stimulus package signed by Obama. Retrieved December 2, 2011, from http//www. myemrstimulus. com/tag/emr-software/ Omni MD (n. d. ). Medicaid, health IT to see billions from stimulus package signed by Obama. Retrieved December 2, 2011, from http//www. myemrstimulus. com/tag/emr-software/ Terri Emerick (2006). Part DRx for Disaster. Retrieved December 2, 2011, from http//www. epluribusmedia. org/archives/features/2006/0511part_d. html

Hayleys Consumer HR policy

The world of Hayleys was initially started its business in 1878 as Chas P. Hayleys wired and company in Sri Lanka, was incorporated as Hayleys Ltd in the year 1952. Today it is known as the world of Hayelys with a globally competitive business portfolio spanning over 12 different sectors of enterprise. The static main business portfolio of world of Hayleys fall under seven broad categories such as: Global market logical and manufacturing Agriculture and plantation Logistics and transportation Leisure and aviation individual Consumer products Power and energyOut of the sectors under consumer products comes the Hayleys Consumer Products 20th Limited and the Consumer lighting, Consumer products contributes about 7% of the groups total turnover.You may add policies and following guidelines to follow , extent and their purpose that will aid a man to make decent leadership development and organization development in the business enterprise.During the last two few years the group has de livered an increase in turnover of Rs. . 1 bn from the previous financial year. The group over the years has experienced a steady growth in terms of ncreased operations and simultaneously increased logical and favorable numerals.Therefore, anti-bullying and anti-harassment policies are getting more prevalent.

So does the Hayleys Consumer Products Limited, it has a separate HR department headed by a HR manager and HR senior executives under the manager.Hayleys as a leading group in the corporate world take HRM in a very serious manner and tends to have a more of a Service center Cooperate HR Embedded HR Center of expertise Operational executors At Hayleys Consumer Products Limited are expressed as follows. 2. 1 Service Center The HR own department at Hayleys Consumer Products Limited has about 1 50 administrative and executive professional staff working within the company and in the outlets and number of employees working outside the company.Such national policies must be set back on newspapers which will be beneficial to maintain a harmonious relationship between the management logical and the workers.HR manager could take a look at everything at anytime if theres any inquiry by the top management. Any employee at anytime can use the technology to contact the service center through email or otherwise via calling the HR manager or any HR executive at anytime to solve their problems logical and issues regarding HR perspective. Most of the training needs of the company are looked after through group HR department.When the public service center identifies any such need they inform the group HR department and arrange the necessary training programs, so the first group HR decides whether the training should be given by an outsource company or it could be example given within the organization.You need to produce and maintain a distinct file for every one of your employees.

Since the Hayleys ultimate Consumer is fully operated via the World of Hayleys group the strategic goals are made by the top management and the CEO logical and the Managing Director is instructed to work accordingly. Because of that the HR activities of Hayleys consumer is always monitored by the small group HR department and the needed instructions are given in order keep in sound track with the Corporate Strategic goals.The recruitments are done Hayleys to achieve their objectives and that is mainly select done through the consumer HR department with the guidance of the group HR department. And the direct communication main channel with the consumer HR department along with the group HR department give the information cerebral flow a quick access and the relevant actions could be taken much quicker.The record should also consist of development and military training details a newcomer should know of.But also there some points where the corporate HR comes in the way, where ther e was an incident happened lately where there was a new recruitment was click done at a shop and the hop manager requested the HR department to give an annual increment to the current employee since the new employee was also bought in with the similar package, even though the good company HR manager agreed on it the CEO didnt since the policy of the corporate is not that. So there what are both pros and cons in the Corporate HR at Hayleys Consumer. 2. Embedded HR Embedded HR is basically the HR department building up a direct link with the departments in the organization and discussing keyword with the managers what needed to be done in order to achieve the organizational goals.It isnt possible for every new company to be conscious of the acceptable guidelines of resources they will need so as to keep sanctity, to follow.

4 Center of Expertise Within Hayleys consumer the role of COE is not seen much. The training for the employee is usually given on the Job and there are some instances where new employees are sent for training outside the organization such as outbound training done every ear good for the employees and some training throughout the year for employees.Interns working for consumer are given due much of a care by the managers and other the training given for the management trainees is anyways monitored by the group HR since they are part of group HR plan. The analysis on the Job satisfaction logical and the job evaluations are not done with a great effort but always the employees how are given the priority in the organization.Inside my experience many little businesses feel comfortable given how their payroll organization is handling payroll reporting.The business is a microfinance company.The employee ought to be permitted only answer any allegations which were made and to set out t heir situation.

Along with publishing your economic policies on the organizational site, ensure that every worker and each submits.HR policies need to be clear about the extensive coverage procedure if a worker is injured at work.HR policies arent apparent.Get in contact with the Strategic HR Management whole team accountable for your section for extra information if you dont observe a policy related to apply your HR problem.