Mentorship and Competence Paper Essay Example | Topics and Well Written Essays - 1500 words

Mentorship and Competence Paper - Essay Example I believed that through the mentoring program, I would have access not only to information but also an update of my skills and a reinforcement of my confidence at work. As I began the mentorship program, I was delighted to find that the learning outcomes were explicitly laid out. It all complemented my own objectives and, in addition, it provided other important aspects especially in those areas that I was not able to identify. Efficacy I would like to say that the mentorship program I have just undertaken is learner-centred, which, in my opinion, was what made it effective. It included many activities and strategies that improved learning and enriched the experience. For instance, I found the incorporation of reflections on prior experience as extremely helpful. Based on this, I took the initiative to write my own journal to chronicle my thoughts and my progress during the entire program. This aspect in the mentoring course allowed me to identify critical incidents, progresses made, future learning needs and analyze them so that I am able to enrich and inform my interactions with my mentors. Interestingly, the whole exercise made me more involved. I think that it added to the motivating factors that diminished my reservations and anxiety about sharing personal thoughts and professional capacities as well as in dealing with getting reviewed by my peers. Through reflections, I was able to do some forward planning to meet the course outcomes. I discovered that I have this capability for self-direction as well. Then I would have to emphasize the importance of the course content. There are two pieces of literature that I have to cite here. The first the Standards to support learning and assessment in practice, a Nursing and Midwifery Council's (NMC) standards for mentors, practice teachers and teachers. The second is Kathleen Duffy's Failing students: a qualitative study of factors that influence the decisions regarding assessment of students' competence in practic e. Both of these texts provided important insights on the mentorship experience and objectives. The first contextualized the entire program from the perspective of the mentors whereas Duffy's article explained the program's concern when it comes to the students, which is competence in practice. NMC and Regulations The NMC publication provides several important information. It explained the rationale behind the program by identifying the principles behind its mandate. There was a clear outline of the relationship between the course, the update of skills, best practices and the public good. It cited relevant statutes and regulations that are crucial in thoroughly understanding not just the program but the need for regulatory framework that encompasses it. These information contextualized the whole initiative according to my experience with respect to the community and environment where I would practice my profession. The main content of the NMC publication is the description of requir ements and rules that govern the learning and assessments of students as well as the nursing and midwifery practice. For example, there is the equality and diversity requirements, which promote equal opportunity. There are also those concerning post-qualifying programs such as the Specialist Practice (SPQ) and the Modernising Nursing Careers position paper. Collectively, these elements depict a coherent regulatory framew

Business Assignment Example | Topics and Well Written Essays - 2250 words

Business - Assignment Example This report stresses that recent country-by-country study analysis of globalization reveals many surprises and interesting bits. The study shows that there are high possibilities of continued integration of economies world over as well as more than five percent increase in gross domestic products. In addition, there is enormous room for world connectedness to expand which will be of various benefits in the international business. This paper makes a conclusion that mutual respect, healthy interdependency, cross cultural communication and effective leadership are some of the most appropriate ways through which a successful Global project management can become a reality. Without the implementation of the above factors such that that leadership lacks authority, power and control over employees, then the project’s destination is failure. Using cross-cultural teams effectively in projects provides a massive source of experience as well as innovative thinking that enhance innovation and competitiveness of their organizations. Managements should also make proper efforts to eliminate communication barriers that may hinder openness and transparency in the organization. Discriminatory cultures and principles should also not find a leeway into any organization. It is therefore important that managers should also give room for innovation, creativity and motivation by offering flexible leadership.

Terminator Wave Energy Devices

Terminator Wave Energy Devices 1.0 Executive Summary The offshore ocean wave energy resource, as a derivative form of solar energy, has considerable potential for making a significant contribution to the alternative usable energy supply.Wave power devices are generally categorized by the method used to capture the energy of the waves. They can also be categorized by location and power take-off system. The energy extraction methods or operating principles can be categorized into three main groups; (1) Oscillating water Column (OWC) (2) Overtopping Devices (OTD) (3) Wave Activated Bodies (WAB); Locations are shoreline, near shore and offshore. This report discusses about Terminator wave energy devices which extend perpendicular to the direction of wave travel and capture or reflect the power of the wave. These devices are typically onshore or near shore; however, floating versions have been designed for offshore applications. 2.0 Introduction Traditional sources of energy such as oil, gas, and coal are non-renewable. They also create pollution by releasing huge quantities of carbon dioxide and other pollutants into the atmosphere. In contrast, waves are a renewable source of energy that doesnt cause pollution. The energy from waves alone could supply the worlds electricity needs. The total power of waves breaking on the worlds coastlines is estimated at 2 to 3 million megawatts. In some locations, the wave energy density can average 65 megawatts per mile of coastline. The problem is how to harness wave energy efficiently and with minimal environmental, social, and economic impacts. Ocean waves are caused by the wind as it blows across the open expanse of water, the gravitational pull from the sun and moon, and changes in atmospheric pressure, earthquakes etc. Waves created by the wind are the most common waves and the waves relevant for most wave energy technology. Wave energy conversion takes advantage of the ocean waves caused primarily by the interaction of winds with the ocean surface. Wave energy is an irregular oscillating low-frequency energy source. They are a powerful source of energy, but are difficult to harness and convert into electricity in large quantities. The energy needs to be converted to a 60 or 50 Hertz frequency before it can be added to the electric utility grid. Part of the solar energy received by our planet is converted to wind energy through the differential heating of the earth. In turn part of the wind energy is transferred to the water surface, thereby forming waves. While the average solar energy depends on factors such as local climate and latitude, the amount of energy transferred to the waves and hence their resulting size depends on the wind speed, the duration of the winds and the duration over which it blows. The most energetic waves on earth happen to be between 30 degrees to 60 degrees latitude, in general the waves generated are stronger on the southern parts of the countries (John brook, ECOR). Wave power devices extract energy directly from the surface motion of ocean waves or from pressure fluctuations below the surface. Wave power varies considerably in different parts of the world, and wave energy cant be harnessed effectively everywhere. It has been estimated that if less than 0.1% of the renewable energy available within the oceans could be converted into electricity, it would satisfy the present world demand for energy more than five times over. A variety of technologies are available to capture the energy from waves. Wave technologies have been designed to be installed in near shore, offshore, and far offshore locations. Offshore systems are situated in deep water, typically of more than 40 meters (131 feet). Types of power take-off include: hydraulic ram, elastomeric hose pump, pump-to-shore, hydroelectric turbine, air turbine and linear electrical generator. Some of these designs incorporate parabolic reflectors as a means of increasing the wave energy at the point of capture. 3.0 Type of Wave Energy Converters Ocean waves represent a form of renewable energy created by wind currents passing over open water. Many devices are being developed for exploiting wave energy. The energy extraction methods or operating principles can be categorized into three main groups (Harris Robert E. et al.): Oscillating Water Columns (OWC) Waves cause the water column to rise and fall, which alternately compresses and depressurize an air column. The energy is extracted from the resulting oscillating air flow by using a Wells turbine Overtopping Devices (OTD) Ocean waves are elevated into a reservoir above the sea level, which store the water. The energy is extracted by using the difference in water level between the reservoir and the sea by using low head turbines Wave Activated Bodies (WAB) Waves activate the oscillatory motions of body parts of a device relative to each other, or of one body part relative to a fixed reference. Primarily heave, pitch and roll motions can be identified as oscillating motions whereby the energy is extracted from the relative motion of the bodies or from the motion of one body relative to its fixed reference by using typically hydraulic systems to compress oil, which is then used to drive a generator. The wave activated bodies (WABs) can be further categorized in sub-groups describing the energy extraction by the principle motion of the floating body (heave, pitch and roll). A variety of technologies have been proposed to capture the energy from waves based on above extraction methods; Some of the technologies that have been the target of recent developmental efforts and are appropriate for the offshore applications being considered are terminators, attenuators and point absorbers (U.S. Department of the Interior, May 2006). Figure 1: Schematic drawings of WEC devices for operating principles and principal locations(Harris Robert E. et al.) The many different types of wave energy converters (WECs) can be classified in to various ways depending on their horizontal size and orientation. If the size is very small compared to the typical wavelength the WEC is called a point absorber. In contrast if the size is comparable to or larger than the typical wavelength, the WEC is known as line absorber, this can also be referred to as terminator or attenuator. A WEC is called terminator or attenuator if it is aligned along or normal to the prevailing direction of the wave crest respectively (John brook, ECOR). The relationship between the three main classifications Principal Location Operating Principle Directional Characteristic: These classifications are shown in Figure 2, presenting the possible operating principles for the location and the directional characteristics. At the shoreline the only feasible operating principles are oscillating water columns and overtopping devices, which are terminators. Figure shows that at near shore and offshore, point absorber or attenuator devices can only be WABs, whilst for terminator devices all three categories of the operating principles are possible. OWCs and OTDs are ‘static’ energy converters of the terminator kind. As a result their mooring has to be stiff, restraining modes of motions but allowing for adjustment towards a parallel wave approach and for tidal ranges. The station keeping requirements for the mooring of wave activated bodies can be either static or dynamic. Figure 2: Possible operating principles for the principal location and directional characteristic 3.1 Attenuators Attenuators are long multi-segment floating structures oriented parallel to the direction of the wave travel. The differing heights of waves along the length of the device causes flexing where the segments connect, and this flexing is connected to hydraulic pumps or other converters (U.S. Department of the Interior, May 2006). 3.2 Point Absorbers Point absorbers have a small horizontal dimension compared with the vertical dimension and utilize the rise and fall of the wave height at a single point for WEC (Harris Robert E. et al.). It is relatively small compared to the wave length and is able to capture energy from a wave front greater than the physical dimension of the absorber (James, 2007). The efficiency of a terminator or attenuator device is linked to their principal axis being, according, parallel or orthogonal to the incoming wave crest. The point absorber does not have a principal wave direction and is able to capture energy from waves arriving from any direction. As a consequence the station keeping for the terminator and attenuator has to allow the unit to weathervane into the predominant wave direction, but this is not necessary for the point absorber (Harris Robert E. et al.). 3.3 Terminators A Terminator has its principal axis parallel to the incident wave crest and terminates the wave. These devices extend perpendicular to the direction of wave travel and capture or reflect the power of the wave. The reflected and transmitted waves determine the efficiency of the device (Harris Robert E. et al.). These devices are typically installed onshore or near shore; however, floating versions have been designed for offshore applications. (U.S. Department of the Interior, May 2006). There are mainly two types in Terminator WEC. 3.3.1 Oscillating Water Columns (OWC) The oscillating water column (OWC) is a form of terminator in which water enters through a subsurface opening into a chamber with air trapped above it. The wave action causes the captured water column to move up and down like a piston to force the air through an opening connected to a turbine (U.S. Department of the Interior May 2006). The device consists essentially of a floating or (more usually) bottom-fixed structure, whose upper part forms an air chamber and whose immersed part is open to the action of the sea. The reciprocating flow of air displaced by the inside free surface motion drives an air turbine mounted on the top of the structure. 3.3.1.1 Efficiency of Oscillating Water Column (OWC) The efficiency of oscillating water column (OWC) wave energy devices are particularly affected by flow oscillations basically for two reasons. (1) Because of intrinsically unsteady (reciprocating) flow of air displaced by the oscillating water free surface. (2) Because of increasing the air flow rate, above a limit depending on, and approximately proportional to, the rotational speed of the turbine, is known to give rise to a rapid drop in the aerodynamic efficiency and in the power output of the turbine. A method which has been proposed to partially circumvent this problem consists in controlling the pitch of the turbine rotor blades in order to prevent the instantaneous angle of incidence of the relative flow from exceeding the critical value above which severe stalling occurs at the rotor blades (see Gato and FalcaËÅ"o, 1991). Although considered technically feasible (Salter, 1993) this has never been implemented at full scale owing to mechanical difficulties. Alternately, the flow rate through the turbine can be prevented from becoming excessive by equipping the device with air valves. Two different schemes can be envisaged, in the first one, the valves are mounted between the chamber and the atmosphere in parallel with the turbine (by-pass or relief valves, on or near the roof of the air chamber structure) and are made to open (by active or passive control) in order to prevent the overpressure (or the under pressure) in the chamber to exceed a limit which is defined by the aerodynamic characteristics of the turbine at its instantaneous speed. In the second scheme a valve is mounted in series with the turbine in the duct connecting the chamber and the atmosphere. Excessive flow rate is prevented by partially closing the valve. In both schemes, the air flow through the turbine is controlled at the expense of energy dissipation at the valves. Theoretically the two methods, if properly implemented, are equivalent from the point of view of limiting the flow rate through the turbine. However, the resulting pressure changes in the chamber are different (reduction and increase in pressure oscillations in the first and second cases, respectively). Consequently the hydrodynamic process of energy extraction from the waves is differently modified by valve operation in the two control methods. The main purpose of this work is to analyse theoretically the performance of an OWC wave energy device when valves are used to limit the flow through the turbine. Both schemes are considered and compared: a valve (or a set of valves) mounted in parallel with the turbine (by-pass or relief valve) or a valve mounted in the turbine duct. The hydrodynamic analysis is done in the time domain for regular as well as for irregular waves. The spring-like effect due to the compressibility of the air is taken into account and is discussed in some detail. Realistic characteristics are assumed for the turbine. Numerical results are presented for simple two-dimensional chamber geometry for whose hydrodynamic coefficients analytical expressions are known as functions of wave frequency. 3.3.2 Overtopping Devices (OTD) Overtopping devices have reservoirs that are filled by impinging waves to levels above the average surrounding ocean. The released reservoir water is used to drive hydro turbines or other conversion devices. Overtopping devices have been designed and tested for both onshore and floating offshore applications. It gathers the energy by waves overtopping into a raised reservoir, and extracting this by draining the water through low head turbines. OTD consists of three main elements: Two wave reflectors. Attached to the central platform these act to focus the incoming waves. The main platform. This is a floating reservoir with a doubly curved ramp facing the incoming waves. The waves overtop the ramp which has a variable crest freeboard 1 to 4 m and underneath the platform open chambers operate as an air cushion maintaining the level of the reservoir. Hydro turbines. A set of low head turbines converts the hydraulic head in the reservoir (Tedd James et al., 2005) 3.3.2.1 Overtopping theory The theory for modeling overtopping devices varies greatly from the traditional linear systems approach used by most other WECs. A linear systems approach may be used with overtopping devices. This considers the water oscillating up and down the ramp as the excited body, and the crest of the ramp as a highly non-linear power take off system. However due to the non-linearities it is too computationally demanding to model usefully. Therefore a more physical approach is taken. Figure 4 shows the schematic of flows for the Wave Dragon. Depending on the current wave state (HS, Tp) and the crest freeboard Rc(height of the ramp crest above mean water level, MWL) of the device, water will overtop into the reservoir Qovertopping. The power gathered by the reservoir is a product of this overtopping flow, the crest freeboard and gravity. If the reservoir is over filled when a large volume is deposited in the basin there will be loss from it Qspill. To minimize this, the reservoir level h must be kept below its maximum level hR. The useful hydraulic power converted by the turbines is the product of turbine flow Qturbine, the head across them, water density and gravity (Tedd James et al., 2005). In coastal engineering the average flow Q is converted into non dimensional form by dividing by the breadth of the device b, gravity g and the significant wave height HS: In the case of the floating OTD it has been seen that there is a dependency on the wave period. The dominant physical explanation for this is the effect of energy passing beneath the draft of the structure. Figure 6 Layout of OTD 3.3.2.2 Wave Reflector Wings One of the most distinctive aspects of the Overtopping WEC is the long slender wings mounted to the front corners of the reservoir platform. These are designed to reflect the oncoming waves towards the ramp. A wider section of wave is available to be exploited with only a moderate increase in capital cost. The overtopping volume in a wave is very dependent on the wave height; therefore by providing only a moderate increase in height, much more energy can overtop the ramp. In order to choose the correct lengths, angles, and position of these wings extensive computer modelling is used. Secondary bonuses of the presence of the wave reflector wings include: better weather-vaning performance to face the waves, lower peak mooring forces, and improved horizontal stability of the main platform. As the aft and rear mooring attachment points are separated further, the yaw of the platform is more stable. Therefore the device will not turn away from the predominant wave direction, and will also realign itself faster as when the wave direction changes (Tedd James et al., 2005). Lastly the reflectors wings act as stabilisers to the device. As they float under their own buoyancy they counteract any list of the platform. This is important as the more horizontal the platform is kept the less water is spilt and so the more efficient the device operation. 3.3.2.3 Low Head Turbines and Power Train Turbine operating conditions in a WEC are quite different from the ones in a normal hydro power plant. In the OTD, the turbine head range is typically between 1.0 and 4.0 m, which is on the lower bounds of existing water turbine experience. While there are only slow and relatively small variations of flow and head in a river hydro power plant, the strong stochastic variations of the wave overtopping call for a radically different mode of operation in the OTD. The head, being a function of the significant wave height, is varying in a range as large as 1:4, and the discharge has to be regulated within time intervals as short as ten seconds in order to achieve a good efficiency of the energy exploitation (Tedd James et al., 2005). On an unmanned offshore device, the environmental conditions are much rougher, and routine maintenance work is much more difficult to perform. Special criteria for the choice and construction of water turbines for the WEC have to be followed; it is advisable to aim for constructional simplicity rather than maximum peak efficiency. Figure 6 shows the application ranges of the known turbine types in a graph of head H vs. rotational speed nq. The specific speed nq is a turbine parameter characterizing the relative speed of a turbine, thus giving an indication of the turbines power density. Evidently, all turbine types except the Pelton and the cross flow type are to be found in a relatively narrow band running diagonally across the graph. Transgressing the left or lower border means that the turbine will run too slowly, thus being unnecessarily large and expensive. The right or upper border is defined by technological limits, namely material strength and the danger of cavitations erosion. The Pelton and the cross-flow turbine do not quite follow these rules, as they have a runner which is running in air and is only partially loaded with a free jet of water. Thus, they have a lower specific speed and lower power density. Despite its simplicity and robustness, the cross flow turbine is not very suitable for OTD applications (Tedd James et al., 2005). Figure 7 Head range of the common turbine types, Voith and Ossberger 3.3.2.4 Performance in Storms Survivability is essential, and Overtopping devices are naturally adapted to perform well in storm situations, where the wave will pass over and under the device with no potential end-stop problems. 3.3.2.5 Wave Prediction Performance of almost all wave energy converters can be improved with prediction of the incoming waves. The cost to implement would be low as the control hardware is typically in place, only the measuring system and improved control techniques need to be developed. To explain the concept behind the device a simple example can be used. If a measurement of some wavelengths ahead of the wave energy converter shows large waves passing, then at a given time later this energy will be incident on the device. The control of the device can then be altered quickly to extract this larger energy, e.g. by increasing hydraulic resistance to an oscillator’s motion allowing more energy to be captured within the stroke length, or by draining the reservoir of an overtopping device to allow for a large overtopping volume(Tedd James et al., 2005). The challenges are threefold; to implement a system for measuring the waves approaching the ramp, to accurately transform this into usable input for the control systems, and to construct new control strategies to make the best use of this. The standard approach for performing such deterministic sea-state prediction involves discrete frequency domain techniques. This is computationally intensive, as the two Fourier transforms must be made to convert from the time domain to the frequency domain and return to the time domain. 3.4 Energy Capture and Practical Limits The power captured from waves by the primary mechanical conversion (before secondary conversion to electrical power) can be related to the energy in the incoming waves over a certain width. Theoretical values have been established in some cases. For a heaving axi-symmetric body the maximum capture width is the inverse of the wave number. The capture width is often compared to the front width of the device. This width ratio can be larger than one for a point absorber with small dimensions compared to the wavelength. Viscous effects reduce efficiency. For an OWC, Wang et al. (2002) found that the capture width ratio may reach a value of 3 and above at an optimum wave period. For Pelamis, Retlzler et al. (2001) found a capture width up to 2 in regular waves and around one in random seas (Specialist Committee V.4, 2006). A continuous or a semi discrete array of wave energy converters acting as an absorbing wall perpendicular to the wave direction is called a terminator and its capture width equals the width of the device and is not related to the length of the incident waves. As the wave conditions are stochastic, the tuning parameters of the energy converters are compromises between the optimum values at various sea conditions. The capture width must be established for each sea state. Fixed devices are subject to sea level variation according to tidal effects. This is critical for fixed oscillating water columns and fixed overtopping systems whose performances are dependent on the mean sea level. The intake of an OWC must be located at an optimised design level from the mean free surface. The height of an overtopping system is also optimised for sea states occurring at a given mean sea level. Therefore, sites with minimal tide are preferred. From this point of view floating devices are more suitable. The immersion of a floating device can also be tuned with respect to the actual sea state. For instance the Wave Dragon overtopping device is partially floating on air chambers and its draught can be modified (Specialist Committee V.4, 2006). The performance of the overtopping device is sensitive to the distribution of the overtopping rate. The more variable the overtopping flow into the reservoir, the larger the capacity of the reservoir and turbines must be to achieve the same performance. 4.0 Mooring Requirements The two major requirements for a WEC mooring are to withstand the environmental and other loadings involved in keeping the device on station, and to be sufficiently cost effective so that the overall economics of the device remain viable. The following list shows the requirements that need to be considered for WEC moorings systems (Harris Robert E. et al.): The primary purpose of the mooring system is to maintain the floating structure on station within specified tolerances under normal operating load and extreme storm load conditions. The excursion of the device must not permit tension loads in the electrical transmission cable(s) and should allow for suitable specified clearance distances between devices in multiple installations. The mooring system must be sufficiently compliant to the environmental loading to reduce the forces acting on anchors, mooring lines and the device itself to a minimum; unless the stiffness of the mooring itself is an active element in the wave energy conversion principle used. All components must have adequate strength, fatigue life and durability for the operational lifetime, and marine growth and corrosion need to be considered. A degree of redundancy is highly desirable for individual devices, and essential for schemes which link several devices together. The system as a whole should be capable of lasting for 30 years or more, with replacement of particular components at no less than 5 years. The mooring must be sufficient to accommodate the tidal range at the installation location. The mooring system should allow the removal of single devices without affecting the mooring of adjacent devices. Removal of mooring lines for inspection and maintenance must be possible. The mooring must be sufficiently stiff to allow berthing for inspection and maintenance purposes. Contact between mooring lines must be avoided. The mooring should not adversely affect the efficiency of the device, and if it is part of an active control system it must also be designed dynamically as part of the overall WEC system. Revenues from WECs, in comparison to the offshore industry, are smaller and their economics more strongly linked to the location, installation costs and down time periods. The mooring system has an important impact on the economics and it is necessary to provide, at low installation cost, a reliable system that has little downtime and long intervals between maintenance. The suitability of design approaches from the offshore industry for WECs are ranked in Appendix I (Harris Robert E. et al.). 5.0 Environmental Considerations Conversion of wave energy to electrical or other usable forms of energy is generally anticipated to have limited environmental impacts. However, as with any emerging technology, the nature and extent of environmental considerations remain uncertain. The impacts that would potentially occur are also very site specific, depending on physical and ecological factors that vary considerably for potential ocean sites. As large-scale prototypes and commercial facilities are developed, these factors can be expected to be more precisely defined (U.S. Department of the Interior, May 2006). The following environmental considerations require monitoring (U.S. Department of the Interior, May 2006). Visual appearance and noiseare device-specific, with considerable variability in visible freeboard height and noise generation above and below the water surface. Devices with OWCs and overtopping devices typically have the highest freeboard and are most visible. Offshore devices would require navigation hazard warning devices such as lights, sound signals, radar reflectors, and contrasting day marker painting. However, Coast Guard requirements only require that day markers be visible for 1 nautical mile (1.8 km), and thus offshore device markings would only be seen from shore on exceptionally clear days. The air being drawn in and expelled in OWC devices is likely to be the largest source of above-water noise. Some underwater noise would occur from devices with turbines, hydraulic pumps, and other moving parts. The frequency of the noise may also be a consideration in evaluating noise impacts. Reduction in wave height from wave energy converterscould be a consideration in some settings; however, the impact on wave characteristics would generally only be observed 1 to 2 km away from the WEC device in the direction of the wave travel. Thus there should not be a significant onshore impact if the devices were much more than this distance from the shore. None of the devices currently being developed would harvest a large portion of the wave energy, which would leave a relatively calm surface behind the devices. It is estimated that with current projections, a large wave energy facility with a maximum density of devices would cause the reduction in waves to be on the order of 10 to 15%, and this impact would rapidly dissipate within a few kilometers, but leave a slight lessening of waves in the overall vicinity. Little information is available on the impact on sediment transport or on biological communities from a reduction in wave height offshore. An isolated impact, such as reduced wave height for recreational surfers, could possibly result. Marine habitatcould be impacted positively or negatively depending on the nature of additional submerged surfaces, above-water platforms, and changes in the seafloor. Artificial above-water surfaces could provide habitat for seals and sea lions or nesting areas for birds. Underwater surfaces of WEC devices would provide substrates for various biological systems, which could be a positive or negative complement to existing natural habitats. With some WEC devices, it may be necessary to control the growth of marine organisms on some surfaces. Toxic releasesmay be of concern related to leaks or accidental spills of liquids used in systems with working hydraulic fluids. Any impacts could be minimized through the selection of nontoxic fluids and careful monitoring, with adequate spill response plans and secondary containment design features. Use of biocides to control growth of marine organisms may also be a source of toxic releases. Conflict with other sea space users, such as commercial shipping and fishing and recreational boating, can occur without the careful selection of sites for WEC devices. The impact can potentially be positive for recreational and commercial fisheries if the devices provide for additional biological habitats. Installation and Decommissioning: Disturbances from securing the devices to the ocean floor and installation of cables may have negative impacts on marine habitats. Potential decommissioning impacts are primarily related to disturbing marine habitats that have adapted to the presence of the wave energy structures. 6.0 Discussions A vast number of parameters influence (and interact with) the net power production from any WEC: Overtopping, determined by Free-board (adjustable in Wave Dragons) Actual wave height Physical dimension of the converter (ramps, reflectors etc. Outlet, determined by Size of reservoir Turbine design Turbine on/off strategy Mooring system, free or restricted orientation toward waves Size of the energy converter Wave climate Energy in wave front (kW/m) Distribution of wave heights Availability Theoretical availability; Reliability, maintainability, serviceab Terminator Wave Energy Devices Terminator Wave Energy Devices 1.0 Executive Summary The offshore ocean wave energy resource, as a derivative form of solar energy, has considerable potential for making a significant contribution to the alternative usable energy supply.Wave power devices are generally categorized by the method used to capture the energy of the waves. They can also be categorized by location and power take-off system. The energy extraction methods or operating principles can be categorized into three main groups; (1) Oscillating water Column (OWC) (2) Overtopping Devices (OTD) (3) Wave Activated Bodies (WAB); Locations are shoreline, near shore and offshore. This report discusses about Terminator wave energy devices which extend perpendicular to the direction of wave travel and capture or reflect the power of the wave. These devices are typically onshore or near shore; however, floating versions have been designed for offshore applications. 2.0 Introduction Traditional sources of energy such as oil, gas, and coal are non-renewable. They also create pollution by releasing huge quantities of carbon dioxide and other pollutants into the atmosphere. In contrast, waves are a renewable source of energy that doesnt cause pollution. The energy from waves alone could supply the worlds electricity needs. The total power of waves breaking on the worlds coastlines is estimated at 2 to 3 million megawatts. In some locations, the wave energy density can average 65 megawatts per mile of coastline. The problem is how to harness wave energy efficiently and with minimal environmental, social, and economic impacts. Ocean waves are caused by the wind as it blows across the open expanse of water, the gravitational pull from the sun and moon, and changes in atmospheric pressure, earthquakes etc. Waves created by the wind are the most common waves and the waves relevant for most wave energy technology. Wave energy conversion takes advantage of the ocean waves caused primarily by the interaction of winds with the ocean surface. Wave energy is an irregular oscillating low-frequency energy source. They are a powerful source of energy, but are difficult to harness and convert into electricity in large quantities. The energy needs to be converted to a 60 or 50 Hertz frequency before it can be added to the electric utility grid. Part of the solar energy received by our planet is converted to wind energy through the differential heating of the earth. In turn part of the wind energy is transferred to the water surface, thereby forming waves. While the average solar energy depends on factors such as local climate and latitude, the amount of energy transferred to the waves and hence their resulting size depends on the wind speed, the duration of the winds and the duration over which it blows. The most energetic waves on earth happen to be between 30 degrees to 60 degrees latitude, in general the waves generated are stronger on the southern parts of the countries (John brook, ECOR). Wave power devices extract energy directly from the surface motion of ocean waves or from pressure fluctuations below the surface. Wave power varies considerably in different parts of the world, and wave energy cant be harnessed effectively everywhere. It has been estimated that if less than 0.1% of the renewable energy available within the oceans could be converted into electricity, it would satisfy the present world demand for energy more than five times over. A variety of technologies are available to capture the energy from waves. Wave technologies have been designed to be installed in near shore, offshore, and far offshore locations. Offshore systems are situated in deep water, typically of more than 40 meters (131 feet). Types of power take-off include: hydraulic ram, elastomeric hose pump, pump-to-shore, hydroelectric turbine, air turbine and linear electrical generator. Some of these designs incorporate parabolic reflectors as a means of increasing the wave energy at the point of capture. 3.0 Type of Wave Energy Converters Ocean waves represent a form of renewable energy created by wind currents passing over open water. Many devices are being developed for exploiting wave energy. The energy extraction methods or operating principles can be categorized into three main groups (Harris Robert E. et al.): Oscillating Water Columns (OWC) Waves cause the water column to rise and fall, which alternately compresses and depressurize an air column. The energy is extracted from the resulting oscillating air flow by using a Wells turbine Overtopping Devices (OTD) Ocean waves are elevated into a reservoir above the sea level, which store the water. The energy is extracted by using the difference in water level between the reservoir and the sea by using low head turbines Wave Activated Bodies (WAB) Waves activate the oscillatory motions of body parts of a device relative to each other, or of one body part relative to a fixed reference. Primarily heave, pitch and roll motions can be identified as oscillating motions whereby the energy is extracted from the relative motion of the bodies or from the motion of one body relative to its fixed reference by using typically hydraulic systems to compress oil, which is then used to drive a generator. The wave activated bodies (WABs) can be further categorized in sub-groups describing the energy extraction by the principle motion of the floating body (heave, pitch and roll). A variety of technologies have been proposed to capture the energy from waves based on above extraction methods; Some of the technologies that have been the target of recent developmental efforts and are appropriate for the offshore applications being considered are terminators, attenuators and point absorbers (U.S. Department of the Interior, May 2006). Figure 1: Schematic drawings of WEC devices for operating principles and principal locations(Harris Robert E. et al.) The many different types of wave energy converters (WECs) can be classified in to various ways depending on their horizontal size and orientation. If the size is very small compared to the typical wavelength the WEC is called a point absorber. In contrast if the size is comparable to or larger than the typical wavelength, the WEC is known as line absorber, this can also be referred to as terminator or attenuator. A WEC is called terminator or attenuator if it is aligned along or normal to the prevailing direction of the wave crest respectively (John brook, ECOR). The relationship between the three main classifications Principal Location Operating Principle Directional Characteristic: These classifications are shown in Figure 2, presenting the possible operating principles for the location and the directional characteristics. At the shoreline the only feasible operating principles are oscillating water columns and overtopping devices, which are terminators. Figure shows that at near shore and offshore, point absorber or attenuator devices can only be WABs, whilst for terminator devices all three categories of the operating principles are possible. OWCs and OTDs are ‘static’ energy converters of the terminator kind. As a result their mooring has to be stiff, restraining modes of motions but allowing for adjustment towards a parallel wave approach and for tidal ranges. The station keeping requirements for the mooring of wave activated bodies can be either static or dynamic. Figure 2: Possible operating principles for the principal location and directional characteristic 3.1 Attenuators Attenuators are long multi-segment floating structures oriented parallel to the direction of the wave travel. The differing heights of waves along the length of the device causes flexing where the segments connect, and this flexing is connected to hydraulic pumps or other converters (U.S. Department of the Interior, May 2006). 3.2 Point Absorbers Point absorbers have a small horizontal dimension compared with the vertical dimension and utilize the rise and fall of the wave height at a single point for WEC (Harris Robert E. et al.). It is relatively small compared to the wave length and is able to capture energy from a wave front greater than the physical dimension of the absorber (James, 2007). The efficiency of a terminator or attenuator device is linked to their principal axis being, according, parallel or orthogonal to the incoming wave crest. The point absorber does not have a principal wave direction and is able to capture energy from waves arriving from any direction. As a consequence the station keeping for the terminator and attenuator has to allow the unit to weathervane into the predominant wave direction, but this is not necessary for the point absorber (Harris Robert E. et al.). 3.3 Terminators A Terminator has its principal axis parallel to the incident wave crest and terminates the wave. These devices extend perpendicular to the direction of wave travel and capture or reflect the power of the wave. The reflected and transmitted waves determine the efficiency of the device (Harris Robert E. et al.). These devices are typically installed onshore or near shore; however, floating versions have been designed for offshore applications. (U.S. Department of the Interior, May 2006). There are mainly two types in Terminator WEC. 3.3.1 Oscillating Water Columns (OWC) The oscillating water column (OWC) is a form of terminator in which water enters through a subsurface opening into a chamber with air trapped above it. The wave action causes the captured water column to move up and down like a piston to force the air through an opening connected to a turbine (U.S. Department of the Interior May 2006). The device consists essentially of a floating or (more usually) bottom-fixed structure, whose upper part forms an air chamber and whose immersed part is open to the action of the sea. The reciprocating flow of air displaced by the inside free surface motion drives an air turbine mounted on the top of the structure. 3.3.1.1 Efficiency of Oscillating Water Column (OWC) The efficiency of oscillating water column (OWC) wave energy devices are particularly affected by flow oscillations basically for two reasons. (1) Because of intrinsically unsteady (reciprocating) flow of air displaced by the oscillating water free surface. (2) Because of increasing the air flow rate, above a limit depending on, and approximately proportional to, the rotational speed of the turbine, is known to give rise to a rapid drop in the aerodynamic efficiency and in the power output of the turbine. A method which has been proposed to partially circumvent this problem consists in controlling the pitch of the turbine rotor blades in order to prevent the instantaneous angle of incidence of the relative flow from exceeding the critical value above which severe stalling occurs at the rotor blades (see Gato and FalcaËÅ"o, 1991). Although considered technically feasible (Salter, 1993) this has never been implemented at full scale owing to mechanical difficulties. Alternately, the flow rate through the turbine can be prevented from becoming excessive by equipping the device with air valves. Two different schemes can be envisaged, in the first one, the valves are mounted between the chamber and the atmosphere in parallel with the turbine (by-pass or relief valves, on or near the roof of the air chamber structure) and are made to open (by active or passive control) in order to prevent the overpressure (or the under pressure) in the chamber to exceed a limit which is defined by the aerodynamic characteristics of the turbine at its instantaneous speed. In the second scheme a valve is mounted in series with the turbine in the duct connecting the chamber and the atmosphere. Excessive flow rate is prevented by partially closing the valve. In both schemes, the air flow through the turbine is controlled at the expense of energy dissipation at the valves. Theoretically the two methods, if properly implemented, are equivalent from the point of view of limiting the flow rate through the turbine. However, the resulting pressure changes in the chamber are different (reduction and increase in pressure oscillations in the first and second cases, respectively). Consequently the hydrodynamic process of energy extraction from the waves is differently modified by valve operation in the two control methods. The main purpose of this work is to analyse theoretically the performance of an OWC wave energy device when valves are used to limit the flow through the turbine. Both schemes are considered and compared: a valve (or a set of valves) mounted in parallel with the turbine (by-pass or relief valve) or a valve mounted in the turbine duct. The hydrodynamic analysis is done in the time domain for regular as well as for irregular waves. The spring-like effect due to the compressibility of the air is taken into account and is discussed in some detail. Realistic characteristics are assumed for the turbine. Numerical results are presented for simple two-dimensional chamber geometry for whose hydrodynamic coefficients analytical expressions are known as functions of wave frequency. 3.3.2 Overtopping Devices (OTD) Overtopping devices have reservoirs that are filled by impinging waves to levels above the average surrounding ocean. The released reservoir water is used to drive hydro turbines or other conversion devices. Overtopping devices have been designed and tested for both onshore and floating offshore applications. It gathers the energy by waves overtopping into a raised reservoir, and extracting this by draining the water through low head turbines. OTD consists of three main elements: Two wave reflectors. Attached to the central platform these act to focus the incoming waves. The main platform. This is a floating reservoir with a doubly curved ramp facing the incoming waves. The waves overtop the ramp which has a variable crest freeboard 1 to 4 m and underneath the platform open chambers operate as an air cushion maintaining the level of the reservoir. Hydro turbines. A set of low head turbines converts the hydraulic head in the reservoir (Tedd James et al., 2005) 3.3.2.1 Overtopping theory The theory for modeling overtopping devices varies greatly from the traditional linear systems approach used by most other WECs. A linear systems approach may be used with overtopping devices. This considers the water oscillating up and down the ramp as the excited body, and the crest of the ramp as a highly non-linear power take off system. However due to the non-linearities it is too computationally demanding to model usefully. Therefore a more physical approach is taken. Figure 4 shows the schematic of flows for the Wave Dragon. Depending on the current wave state (HS, Tp) and the crest freeboard Rc(height of the ramp crest above mean water level, MWL) of the device, water will overtop into the reservoir Qovertopping. The power gathered by the reservoir is a product of this overtopping flow, the crest freeboard and gravity. If the reservoir is over filled when a large volume is deposited in the basin there will be loss from it Qspill. To minimize this, the reservoir level h must be kept below its maximum level hR. The useful hydraulic power converted by the turbines is the product of turbine flow Qturbine, the head across them, water density and gravity (Tedd James et al., 2005). In coastal engineering the average flow Q is converted into non dimensional form by dividing by the breadth of the device b, gravity g and the significant wave height HS: In the case of the floating OTD it has been seen that there is a dependency on the wave period. The dominant physical explanation for this is the effect of energy passing beneath the draft of the structure. Figure 6 Layout of OTD 3.3.2.2 Wave Reflector Wings One of the most distinctive aspects of the Overtopping WEC is the long slender wings mounted to the front corners of the reservoir platform. These are designed to reflect the oncoming waves towards the ramp. A wider section of wave is available to be exploited with only a moderate increase in capital cost. The overtopping volume in a wave is very dependent on the wave height; therefore by providing only a moderate increase in height, much more energy can overtop the ramp. In order to choose the correct lengths, angles, and position of these wings extensive computer modelling is used. Secondary bonuses of the presence of the wave reflector wings include: better weather-vaning performance to face the waves, lower peak mooring forces, and improved horizontal stability of the main platform. As the aft and rear mooring attachment points are separated further, the yaw of the platform is more stable. Therefore the device will not turn away from the predominant wave direction, and will also realign itself faster as when the wave direction changes (Tedd James et al., 2005). Lastly the reflectors wings act as stabilisers to the device. As they float under their own buoyancy they counteract any list of the platform. This is important as the more horizontal the platform is kept the less water is spilt and so the more efficient the device operation. 3.3.2.3 Low Head Turbines and Power Train Turbine operating conditions in a WEC are quite different from the ones in a normal hydro power plant. In the OTD, the turbine head range is typically between 1.0 and 4.0 m, which is on the lower bounds of existing water turbine experience. While there are only slow and relatively small variations of flow and head in a river hydro power plant, the strong stochastic variations of the wave overtopping call for a radically different mode of operation in the OTD. The head, being a function of the significant wave height, is varying in a range as large as 1:4, and the discharge has to be regulated within time intervals as short as ten seconds in order to achieve a good efficiency of the energy exploitation (Tedd James et al., 2005). On an unmanned offshore device, the environmental conditions are much rougher, and routine maintenance work is much more difficult to perform. Special criteria for the choice and construction of water turbines for the WEC have to be followed; it is advisable to aim for constructional simplicity rather than maximum peak efficiency. Figure 6 shows the application ranges of the known turbine types in a graph of head H vs. rotational speed nq. The specific speed nq is a turbine parameter characterizing the relative speed of a turbine, thus giving an indication of the turbines power density. Evidently, all turbine types except the Pelton and the cross flow type are to be found in a relatively narrow band running diagonally across the graph. Transgressing the left or lower border means that the turbine will run too slowly, thus being unnecessarily large and expensive. The right or upper border is defined by technological limits, namely material strength and the danger of cavitations erosion. The Pelton and the cross-flow turbine do not quite follow these rules, as they have a runner which is running in air and is only partially loaded with a free jet of water. Thus, they have a lower specific speed and lower power density. Despite its simplicity and robustness, the cross flow turbine is not very suitable for OTD applications (Tedd James et al., 2005). Figure 7 Head range of the common turbine types, Voith and Ossberger 3.3.2.4 Performance in Storms Survivability is essential, and Overtopping devices are naturally adapted to perform well in storm situations, where the wave will pass over and under the device with no potential end-stop problems. 3.3.2.5 Wave Prediction Performance of almost all wave energy converters can be improved with prediction of the incoming waves. The cost to implement would be low as the control hardware is typically in place, only the measuring system and improved control techniques need to be developed. To explain the concept behind the device a simple example can be used. If a measurement of some wavelengths ahead of the wave energy converter shows large waves passing, then at a given time later this energy will be incident on the device. The control of the device can then be altered quickly to extract this larger energy, e.g. by increasing hydraulic resistance to an oscillator’s motion allowing more energy to be captured within the stroke length, or by draining the reservoir of an overtopping device to allow for a large overtopping volume(Tedd James et al., 2005). The challenges are threefold; to implement a system for measuring the waves approaching the ramp, to accurately transform this into usable input for the control systems, and to construct new control strategies to make the best use of this. The standard approach for performing such deterministic sea-state prediction involves discrete frequency domain techniques. This is computationally intensive, as the two Fourier transforms must be made to convert from the time domain to the frequency domain and return to the time domain. 3.4 Energy Capture and Practical Limits The power captured from waves by the primary mechanical conversion (before secondary conversion to electrical power) can be related to the energy in the incoming waves over a certain width. Theoretical values have been established in some cases. For a heaving axi-symmetric body the maximum capture width is the inverse of the wave number. The capture width is often compared to the front width of the device. This width ratio can be larger than one for a point absorber with small dimensions compared to the wavelength. Viscous effects reduce efficiency. For an OWC, Wang et al. (2002) found that the capture width ratio may reach a value of 3 and above at an optimum wave period. For Pelamis, Retlzler et al. (2001) found a capture width up to 2 in regular waves and around one in random seas (Specialist Committee V.4, 2006). A continuous or a semi discrete array of wave energy converters acting as an absorbing wall perpendicular to the wave direction is called a terminator and its capture width equals the width of the device and is not related to the length of the incident waves. As the wave conditions are stochastic, the tuning parameters of the energy converters are compromises between the optimum values at various sea conditions. The capture width must be established for each sea state. Fixed devices are subject to sea level variation according to tidal effects. This is critical for fixed oscillating water columns and fixed overtopping systems whose performances are dependent on the mean sea level. The intake of an OWC must be located at an optimised design level from the mean free surface. The height of an overtopping system is also optimised for sea states occurring at a given mean sea level. Therefore, sites with minimal tide are preferred. From this point of view floating devices are more suitable. The immersion of a floating device can also be tuned with respect to the actual sea state. For instance the Wave Dragon overtopping device is partially floating on air chambers and its draught can be modified (Specialist Committee V.4, 2006). The performance of the overtopping device is sensitive to the distribution of the overtopping rate. The more variable the overtopping flow into the reservoir, the larger the capacity of the reservoir and turbines must be to achieve the same performance. 4.0 Mooring Requirements The two major requirements for a WEC mooring are to withstand the environmental and other loadings involved in keeping the device on station, and to be sufficiently cost effective so that the overall economics of the device remain viable. The following list shows the requirements that need to be considered for WEC moorings systems (Harris Robert E. et al.): The primary purpose of the mooring system is to maintain the floating structure on station within specified tolerances under normal operating load and extreme storm load conditions. The excursion of the device must not permit tension loads in the electrical transmission cable(s) and should allow for suitable specified clearance distances between devices in multiple installations. The mooring system must be sufficiently compliant to the environmental loading to reduce the forces acting on anchors, mooring lines and the device itself to a minimum; unless the stiffness of the mooring itself is an active element in the wave energy conversion principle used. All components must have adequate strength, fatigue life and durability for the operational lifetime, and marine growth and corrosion need to be considered. A degree of redundancy is highly desirable for individual devices, and essential for schemes which link several devices together. The system as a whole should be capable of lasting for 30 years or more, with replacement of particular components at no less than 5 years. The mooring must be sufficient to accommodate the tidal range at the installation location. The mooring system should allow the removal of single devices without affecting the mooring of adjacent devices. Removal of mooring lines for inspection and maintenance must be possible. The mooring must be sufficiently stiff to allow berthing for inspection and maintenance purposes. Contact between mooring lines must be avoided. The mooring should not adversely affect the efficiency of the device, and if it is part of an active control system it must also be designed dynamically as part of the overall WEC system. Revenues from WECs, in comparison to the offshore industry, are smaller and their economics more strongly linked to the location, installation costs and down time periods. The mooring system has an important impact on the economics and it is necessary to provide, at low installation cost, a reliable system that has little downtime and long intervals between maintenance. The suitability of design approaches from the offshore industry for WECs are ranked in Appendix I (Harris Robert E. et al.). 5.0 Environmental Considerations Conversion of wave energy to electrical or other usable forms of energy is generally anticipated to have limited environmental impacts. However, as with any emerging technology, the nature and extent of environmental considerations remain uncertain. The impacts that would potentially occur are also very site specific, depending on physical and ecological factors that vary considerably for potential ocean sites. As large-scale prototypes and commercial facilities are developed, these factors can be expected to be more precisely defined (U.S. Department of the Interior, May 2006). The following environmental considerations require monitoring (U.S. Department of the Interior, May 2006). Visual appearance and noiseare device-specific, with considerable variability in visible freeboard height and noise generation above and below the water surface. Devices with OWCs and overtopping devices typically have the highest freeboard and are most visible. Offshore devices would require navigation hazard warning devices such as lights, sound signals, radar reflectors, and contrasting day marker painting. However, Coast Guard requirements only require that day markers be visible for 1 nautical mile (1.8 km), and thus offshore device markings would only be seen from shore on exceptionally clear days. The air being drawn in and expelled in OWC devices is likely to be the largest source of above-water noise. Some underwater noise would occur from devices with turbines, hydraulic pumps, and other moving parts. The frequency of the noise may also be a consideration in evaluating noise impacts. Reduction in wave height from wave energy converterscould be a consideration in some settings; however, the impact on wave characteristics would generally only be observed 1 to 2 km away from the WEC device in the direction of the wave travel. Thus there should not be a significant onshore impact if the devices were much more than this distance from the shore. None of the devices currently being developed would harvest a large portion of the wave energy, which would leave a relatively calm surface behind the devices. It is estimated that with current projections, a large wave energy facility with a maximum density of devices would cause the reduction in waves to be on the order of 10 to 15%, and this impact would rapidly dissipate within a few kilometers, but leave a slight lessening of waves in the overall vicinity. Little information is available on the impact on sediment transport or on biological communities from a reduction in wave height offshore. An isolated impact, such as reduced wave height for recreational surfers, could possibly result. Marine habitatcould be impacted positively or negatively depending on the nature of additional submerged surfaces, above-water platforms, and changes in the seafloor. Artificial above-water surfaces could provide habitat for seals and sea lions or nesting areas for birds. Underwater surfaces of WEC devices would provide substrates for various biological systems, which could be a positive or negative complement to existing natural habitats. With some WEC devices, it may be necessary to control the growth of marine organisms on some surfaces. Toxic releasesmay be of concern related to leaks or accidental spills of liquids used in systems with working hydraulic fluids. Any impacts could be minimized through the selection of nontoxic fluids and careful monitoring, with adequate spill response plans and secondary containment design features. Use of biocides to control growth of marine organisms may also be a source of toxic releases. Conflict with other sea space users, such as commercial shipping and fishing and recreational boating, can occur without the careful selection of sites for WEC devices. The impact can potentially be positive for recreational and commercial fisheries if the devices provide for additional biological habitats. Installation and Decommissioning: Disturbances from securing the devices to the ocean floor and installation of cables may have negative impacts on marine habitats. Potential decommissioning impacts are primarily related to disturbing marine habitats that have adapted to the presence of the wave energy structures. 6.0 Discussions A vast number of parameters influence (and interact with) the net power production from any WEC: Overtopping, determined by Free-board (adjustable in Wave Dragons) Actual wave height Physical dimension of the converter (ramps, reflectors etc. Outlet, determined by Size of reservoir Turbine design Turbine on/off strategy Mooring system, free or restricted orientation toward waves Size of the energy converter Wave climate Energy in wave front (kW/m) Distribution of wave heights Availability Theoretical availability; Reliability, maintainability, serviceab

art of the hula :: essays research papers

gArt of the Hulaf What is one thing that stands out in most peoples’ minds when they think of Hawaii? Most people would probably say the hula dance. The hula dance descended from, or can be traced to Polynesia and India. The Hula was a form of poetry for the Hawaiians in all of its sacred and ceremonial forms. In hula dancing, the hands are very important: they tell a story. However, more important are the chants. Chanting is an extension of speaking that started as a means of communicating to the gods. The hula can be performed with or without music, but not without the chant. Bamboo sticks, drums, and gourds, are some of the instruments that are played to support the chanting. The chants are very poetic and have many levels of meaning. They believe chanting is a very personal way of expressing feelings and thoughts on a higher level of communication. The topics of the chants may include warfare, death, sex, birth, chiefs, gods, the beauty of the island and water, or even surfing. This exotic culture was hidden from the world until 1778, when Captain James Cook and his men became the first westerners to discover the islands of Hawaii. When they arrived at Kaua’i, the islanders performed the hula dance as a way of greeting the strangers. Later in 1820, Christian missionaries from New England came to the islands, armed with the Bible and narrow-minded thoughts. They were shocked by the â€Å"heathenish† hula, and tried to abolish the dance. The missionaries eventually convinced the royalty, which had been converted to Christianity, to make the hula dance illegal. It was hard for the Hawaiians to retain their culture because the missionaries banned the Hawaiian language from the schools. However, the Hawaiians treasured their culture and dance, and did not let them die. In 1874, King David Kalakaua came to the throne. He is credited with returning the ancient hula dance to the people. European clad, he was known as the Merrie Monarch. He dined with prominent figures including the ever-corrupt President Grant. He had mastered ancient chants taught to him by his grandmother. During his reign, he brought a lot of European style to the hula dance. He integrated hymn singing and band music into traditional hula dance forms. The ukulele and steel guitar were also introduced. It was also during this period when the ti leaf skirt appeared as a hula dance costume.

How Is Othello Viewed By Others And How Does He View Himself Essay

The Shakespearian tragedy ‘Othello’ is a story of immensely contrasting opinions where jealously rules rife over the flawed, but heroic leading character. With racism even alive today, the fact that this character was of dark skin raised even more controversy around the Shakespearian era. The audience that would have first viewed this play would have had preconceptions about the personality and the role that Othello would ensue. Due to the stereotypical and racist viewpoints that people held at this time, black was in any case a colour associated with evil or deformity, therefore the character of the black Othello was expected to be violent, jealous, treacherous and most likely associated with witchcraft. Shockingly, especially for the people of the Shakespearian era, Othello does not relate to this stereotype and is in fact quite the opposite at the start of the play- the calm and strongly composed character. Some of these stereotypical ‘black’ traits however are indeed seen in the play, but controversially from another character, the white Iago, who incidentally plays the role of the evil manipulator. Othello’s character is portrayed to the reader in his composed first words- ‘Tis better as it is’. The line being only a half-line proves his characters’ firm but comfortable personality, needing only to say the controlled necessary in each situation. As his personality seems to be so strong and wise, it is unusual that Iago deems Othello as an easy target to manipulate- ‘will tenderly be lead by the nose as asses are’. Iago’s obvious hatred for Othello is overly emphasised throughout the play by his disregard and lack of respect towards the character. He constantly makes racist comments about Othello to others, but never to Othello himself, naming him- ‘Barbary horse’ to Desdemona’s father and stating that he does ‘hate the Moor’ to Roderigo. Even when referring to the obviously loving relationship that engulfs both Othello and Desdemona, Iago shows ignorant and disrespectful mannerisms, reducing their physical love to animal level- ‘old black ram is tupping your white ewe’ and showing that he obviously does not agree with this martial pairing. Iago’s authentic character is hinted at early on in the tragedy, where in one of his longer speeches he finishes- ‘I am not what I am’. This points the reader towards Iago’s true colours, which are rarely put openly on show. His willingness to manipulate and take advantage of other characters (such as Roderigo) in order to force Othello into the deepest amount of torment proves just how much of a cunning and dangerous actor Iago can be. The ‘stage managing’ techniques he uses throughout the play portray just how determined Iago is to truly ruin Othello’s life and the lengths that he is prepared to reach in order to gain revenge upon Othello for not awarding him the idealised promotion. It is therefore often difficult to decipher Iago’s true feelings and attitudes towards Othello as he constantly adjusts his viewpoint to suit that of his company, for example when in the company of characters such as Othello, Desdemona and Cassio, Iago speaks of Othello positively and even at one point presents a contrasting emotion- ‘My lord, you know I love you’. However, when characters such as Roderigo and Brabantio are in attendance, he again insults Othello naming his supposed arrogance- ‘loving his own pride and purposes’. Although it is apparent that he has strong hatred towards the character, the reasons behind this hatred are never completely discovered. The reader is left to decipher whether the feeling is down to irrepressible racism or dark jealousy, or even a mixture of both. Even when Iago’s shrewd plan is foiled towards the conclusion of the play, his attitudes towards Othello still remain constant. He shows no feeling of remorse and depicts himself as a party holding little guilt- ‘I told him what I thought and told no more than what he found himself was apt and true’ Although this statement if looked at individually is actually truthful (Iago never once stated that Desdemona and Cassio were in fact indefinitely committing adultery), the fact that Iago orchestrated the imaginary relationship between Desdemona and Cassio and that he introduced doubt into Othello’s mind in the knowledge that ambiguity could potentially ruin him, shows that he still aims to manipulate even as the play draws to closure. Iago’s racist views however, are also shared by other characters in the play, the main two named Roderigo and Brabantio. Although both these characters have more personal motives to justify their disapproval of Othello, Iago’s manipulative skills again come into force to emphasise their negative emotions. Until the final moments before his death Roderigo is completely under the influence of Iago and tends to follow his views even if they do not completely match his own. He racially abuses Othello in the company of Iago, naming him- ‘the thick lips’ and ‘lascivious Moor’. These racial prejudices show that he also does not accept the way of which Desdemona and Othello have an indisputable bond, but his apparent hatred goes deeper than this disapproval. As Roderigo is intensely besotted with Desdemona he also seems to be jealous of her love for Othello and believes that the character is not good enough for her, stating that she -‘hath made a gross revolt’. For these reasons Roderigo falls prey to the manipulative Iago, becoming a pawn in his ever growing plot. Unlike Roderigo, Brabantio holds strong racist views about Othello without the influential voice of Iago, showing a genuine condemnation of the relationship between his daughter and -‘the Moor’. This view would have been commonplace in Shakespearian time, as even today principles of racial equality and sexual freedom are unfortunately still far from being completely accepted. He shows legitimate discomfort when referring to the relationship, questioning how Othello could have possibly gained his daughters hand without using some sort of treachery- ‘Is there not charms by which the property of youth and maidhood may be abused?’ Brabantio also finds it understandably challenging to accept that Othello’s intentions of which involve his daughter are honourable -‘Abused her delicate youth with drugs or minerals’. These views would have again been shared by the Shakespearian audience, who associated people of dark skin with witchcraft and trickery. Brabantio may have respected Othello as a military general, as a close acquaintance, and perhaps even as a friend, but it is clear that he never considered Othello good enough to be a husband for his daughter. Characters that form negative or racist views towards Othello do rarely mention these ideas directly to his face, maybe because of his strength as a character, or possibly because of his incessant reputation of being composed and carefully resilient with his language. Each character that states negative views towards the general however is proved at the end of the play to be completely incorrect, and in most cases foolish. Not all characters view Othello in such bad light conversely, most respect him as a brave and honourable general, showing him great loyalty and love- the Duke being one of these. He obviously sees Othello as a brilliant general and valuable friend- ‘Valiant Othello we must straight employ you against the general enemy Ottoman’. Even when Brabantio, a close friend of the Duke, shows obvious racial disagreements towards Othello, the Duke stands up for the general’s cause, stating to Brabantio that his -‘son-in-law is far more fair than black’. This proves that the Duke does accept Othello’s ethnic background and believes that Othello does not hold the usual traits of the stereotypical â€Å"Moor†. Desdemona is unsurprisingly the character that can distinguish Othello as doing no wrong. Even after malicious attacks and verbal abuse from the general, Desdemona does not speak out against her love. Desdemona is infatuated with Othello and this becomes apparent from her very first speech of the play where she states that if she is forced to choose whether to be obedient to her father or to Othello, she must choose Othello- ‘So much I challenge that I may profess due to the Moor my lord.’ She continues with this loyalty throughout the play and clearly sees Othello as an accomplished husband- ‘to his honours and his valiant parts did I my soul and fortunes consecrate’. Desdemona evidently notes that Othello takes his career very seriously and portrays her understanding of this when propositioned by Cassio in order to regain his position of lieutenant- ‘He shall in strangeness stand no farther off than in a politic distance.’ She respects this and endeavours to cause no harm to his reputation and ability. Further on into the play -where jealousy has completely engulfed Othello- Desdemona defends him when questioned by Emilia about whether Othello is in fact covetous, stating that Othello is incapable of feeling such as jealously- she sees him as almost god-like – ‘I think the sun where he was born drew all such humours from him.’ In even the darkest times when Othello acts so awfully and deeply unjustifiably, Desdemona’s love for him still rules strongly over her heart- ‘My love doth so approve him that even his stubbornness, his checks, his frowns-prithee unpin me- have grace and favour in them.’ On her death bed, moments before she is to depart from the world at the hands of her loved one, Desdemona is still unable to speak out against him. She sees through his vicious acts and it is clear to her that the man she married is no longer the corrupted man that stands before her. With her last words to Emilia she states that she doesn’t hold Othello responsible for her death, and even at this perilous moment, names her husband well- ‘Nobody; I myself. Farewell. Commend me to my kind lord.’ She always manages to see Othello positively. Emilia herself, closely linked with Desdemona and often mistreated by her husband Iago, quickly alters her opinion of Othello as the play progresses. Her attitudes towards men are already bitter and derive mainly from the way that Iago has treated her throughout their marriage. She seems to be a feminist and is able to stick up for women- but only in the absence of a male presence. For Emilia the way in which Othello treats Desdemona only emphasises this feeling- ‘they eat us hungerly, and when they are full, they belch us.’ Unfortunately it is evident that Emilia has not always thought of Othello in this negative manner. She awards him the benefit of the doubt as she recognises that his behaviour is becoming erratic and almost stumbles upon Iago’s secret- ‘Remove your thought. It doth abuse your bosom. If any wretch have put this in your head, let heaven requite it with the serpent’s curse!’ Othello’s final behaviour allows Emilia to justify her racist statements- ‘O, more the angel she, and you the blacker devil!’ Othello at his most degrading point in the play reverts to the stereotype that he originally seemed so far from, even though it is apparent to the reader that his reactions are in fact more like Iago’s. Emilia’s final realisation forces her to make yet another racist comment and name Othello as gullible- ‘Oh thou dull moor’. Brabantio’s relative, Lodovico, is the character that shows an obvious change in attitudes towards Othello, in a strikingly short space of time. He undoubtedly thinks well of Othello before his visit to Venice as he greets the general respectfully- ‘God save you, worthy general!’ and clearly accepts his ethnicity. For this reason, Lodovico is clearly shocked when Othello raises his hand to Desdemona and strikes her across the face, and states this surprise and utter disbelief at what he has just witnessed from what was once a courageous general- ‘My lord, this would not be believed in Venice, though I should swear I saw’t.’ This statement gives us a glimpse of how Othello is viewed by others universally. He is seen as a noble character, lacking in the extreme emotions now observed by Lodovico. Brabantio’s relative begins to question Othello’s mental disposition- ‘Are his wits safe? Is he not light of brain?’ and his attitudes have clearly now reversed as he now holds reservations about the stability of Othello’s character, whereas before he was sure that the general was of such a great confidence- ‘Is this the noble Moor that whom our full senate call all-in-all sufficient?’ Lodovico departs from the scene with a controversial and, obvious to the reader, ironic line- ‘I am sorry that I am deceived in him.’ This line shows that Lodovico has lost faith in Othello’s character, and feels almost cheated by what he has seen. It seems unfortunate that he feels as he does towards Othello, when truly as he even speaks the line, Iago is the authentic deceptive culprit. Cassio, the object of hatred in Othello’s eyes, does not really say much about his attitudes towards Othello, but what he does say and what is said about his attitudes by others show what he truly feels towards the general. He obviously shows much loyalty towards Othello, he is his lieutenant and until jealousy sets in, a trusted friend. This is made apparent when Desdemona attempts to change her husband jealous views about the unfairly treated Cassio -‘and so many a time when I have spoke of you dispraisingly hath tane your part’ (Desdemona about Cassio). Even after he has been the subject of confusing and malicious actions by the changed Othello, he still speaks of him well- ‘For he was great of heart.’ This highlights one of Othello’s â€Å"tragic flaws†. He is unable to make a good judge of character, and seems to be enormously gullible, believing the sly Iago over the honest, but sometimes vain, Michael Cassio. Cassio obviously thinks well of the troubled Othello. The views of the characters are extremely varied when involving Othello, and these views are changeable throughout the entirety of the play. However none are as interesting and somewhat confusing as how Othello in fact sees himself. His character goes through three notable stages which seem to show great contrast and diversity with each other. At the beginning of the tragedy Othello is obviously a proud individual, and openly speaks about his noble background- ‘I fetch my life and being from men of royal siege’. He is of distant relation to royalty, and for this reason carries himself with a certain majestic and noble manner. He has a shockingly high opinion of himself and this can sometimes be perceived as an arrogant trait- ‘my parts, my title, and my perfect soul shall manifest me rightly.’ He is dazzlingly confident in almost all aspects of his life and especially when it comes to his military service- ‘For since these arms of mine had seven years’ pith†¦ they have used their dearest action in the tented field’. He proves to be a powerful presence in areas where others would crumble and is passionate about his love for Desdemona, so much so that he is resilient enough to offer everything in order to sustain their love- ‘let your sentence even fall upon my life.’ This shows great strength in character and Othello obviously sees himself as a force to be considered with. At this stage in the play, Othello views himself as never having been a happier due to his love for Desdemona- ‘If it were now to die, ’twere now to be most happy’ and makes a series of prophetically ironic statements, almost unknowingly hinting to the readers of what is to come- ‘But I do love thee; and when I love thee not, chaos is come again.’ The strength in character that we see from Othello throughout the beginning of the play is last seen in a conversation between him and Iago, concerning the infidelity of Desdemona. In his speech, we see Othello at his final point of rational sanity, which unfortunately due to Iago’s manipulative skills, he is unable to keep up throughout the entirety of the play: ‘No, Iago, I’ll see her before I doubt; when I doubt, prove; And on the proof, there is no more but this: Away all at once with love or jealousy!’ After this point in the play, Othello’s view of himself slowly deteriorates. He begins to lose his self-confidence and control as doubt gradually overwhelms his mind. As the jealously sets into his mind, he begins to search for reasons as to why his wife could do such a thing and comes up with two points; his age and his colour- ‘Haply for I am black’, ‘I am declined into the vale of years’. Whereas before he would have stood by Desdemona and perhaps asked for the proof from Iago against his wife’s infidelity, his troubled character now begs Iago to prove the exact opposite- ‘be sure thou prove my love a whore’. His mistrust in Desdemona proves that he is ultimately a poor judge of character, and instead holds his certainty in ‘Honest Iago’. This reliance on Iago to help him judge Desdemona’s true situation in fact becomes his down fall. His self-confidence has travelled from such a high to a low that he sees himself as no longer able to make conscious decisions alone. Othello’s character almost completely morphs into that of Iago, both using extremely similar language and animal imagery at the time of Othello’s extreme jealousy- ‘Goats and monkeys!’, ‘Or keep it as a cistern for foul toads to knot and gender in!’ This illustrates just how reliant on Iago Othello has become. He asks his opinion at almost every opportunity -‘How shall I murder him, Iago?’ This is a complete contrast from how the character was before his mind became jealous as he was before so sure of his each and every decision, so very self-assured. He now sees himself unfit to lead his life without constant supervision from his companion Iago. After being instructed, word-by-word, on how to unjustly murder his beloved Desdemona, Othello commits the terrible deed. Through this scene it is clearly illustrated that Othello has completely lost him mind, and in the words of Iago -‘He is much changed.’ He constantly contradicts himself, showing that he is no longer sure of what he is doing and sees only one way to regain his controlled mind- ‘A murder, which I thought a sacrifice.’ After killing his wife, Othello shows no remorse as he feels that he, himself, has rid the world of an unfaithful being- ‘She’s like a liar gone to burning hell: ‘Twas I that killed her.’ In this way he seems almost proud of his act, but yet still in pieces from losing not only his mind, but in addition, his love. The final stage in Othello’s personality transformation sees him return almost to his former self- a controlled man, but this time with a huge sense of guilt and despair laid upon his heart. He now sees himself as a monster, and begs for punishment’ ‘Whip me†¦ Roast me in sulphur!’ In a desperate effort to regain control in the situation, we see Othello commit an act that would fit with his former character, he stabs himself. This shows that Othello now thinks so badly of himself that he claims happiness will be found in death- ‘For in my sense ’tis happiness to die.’ We see Othello in his final speech attempt to reclaim any respect and decency from his characters, and asks them to remember him as one that ‘loved not wisely, but too well’ and a man that was -‘not easily jealous but, being wrought, perplexed in the extreme’. This shows that Othello has regained control over the final moments of his life and hopes to be remembered not for the tragic deeds he has committed but for his decencies and military service. He views himself as an unfairly mislead man, that inevitably forged his own fate. In conclusion, Othello as a character is not only a controversial, but also travels on such a journey through personalities that he is able to change the opinions of those who once looked up to him. The troubled, aggressive and broken Othello we see at the end of play is a shadow of his former self and proves just how each and every person has strengths and weaknesses that can be carefully manipulated. The real Othello that we see at the beginning of the play is one that can never be regained once jealousy has set in, and this is clearly shown by the tragic ending to the play. Othello tragically saw himself as a strong character, but was eventually shown to be a gullible fool at the hands of the evil manipulative Iago.

Texting And Driving Essay

I do support in the fact that texting a driving should be considered illegal, mainly for the soul purpose that many people die because of the distractions on the road that your phone can cause. â€Å"In the past three years alone, 30 states have banned texting while driving, the only state that has not done it yet is Oklahoma. † (Delcour 2) You see on the news that there are many teenagers now a days that get into car accident why? BECAUSE THEY WERE TEXTING AND DRIVING!â€Å"Last year, despite assurance by S. C.  lawmakers that a texting ban would be passed, obviously it died without coming up for a final vote. †(EDITORIAL 6) I know people who try to text and drive but we always remind them that there are other people in this care ad unless they want the guilt of their friends death due to their carelessness then that’s up to them. When I get behind the wheel of a car I turn my phone to silent and I don’t turn it back up until I that car is stopped and I get out of that car, I don’t sit there at a red light or a stop sign reading text messages or taking calls while I’m behind the wheel of a moving vehicle.It is unsafe to not only you but the people in your car, and the people outside of your car as well like other drivers, pedestrians, animals, etc. I think that if it were to become illegal then it should not only have one ticket for texting while driving but also another one for being stupid to put yourself and other in a dangerous risk of dying or getting seriously hurt. â€Å"Fifty-eight percent of those under 45 say texting while driving should be punished less severely than driving while intoxicated, while 65 percent of those over 45 say the severity of the punishment should be equal for both.† (CBS 6)I am still kind of a new driver myself but I do know how to stay safe on the road from anything that may distract me and end up causing a lot of damage. Dinosaurs have big bodies and small brains, when you st ep inside of a vehicle you now have a big body and a smaller brain. Don’t let that brain of yours end up making stupid decisions behind dangerous machinery like a car. Why do people text and drive? Because they think they can multitask, news flash no you can’t. You cannot pay attention to the road going 70 while talking to your friend at the same time because our minds were meant to comprehend only one thing at a time.Everyone says â€Å"oh I can multitask† and when they do they completely screw something up, just like driving if you don’t pay attention you will screw up bigger than falling off your bike and getting a skinned knee. If this was made illegal I am pretty sure that people wouldn’t obey it at first, but once they get into that accident due to that electronic distraction they will understand why it was made illegal. â€Å"Numerous recent studies document that using wireless communications, and specifically texting, is one of the most da ngerous distractions for a driver, under many circumstances have there been deadly consequences