Sir Gawain and the Green Knight Essay -- essays research papers fc

Women, Courtly Love and the Creation Myth in Sir Gawain and the Green Knight Sir Gawain and the Green Knight, a great epic written in fourteenth century Europe by the Pearl poet, emphasizes the opposition of Christian love to Courtly love in the 13th century through the dilemma of Sir Gawain, one of the great knights of the Arthurian round table. By examining the women in the poem, Gawain's dilemma becomes a metaphor for the contrast of these two distinct types of love. The poem looks upon the Virgin Mary as the representative of spiritual love, obedience, chastity, and life (Warner 9). In contrast, Morgan le Fay and Bertilak's wife appear to be representing courtly love, disobedience, lust and death. This conflict between courtly love and spiritual love demonstrates the drastically weakened religious values behind chivalry. An interesting parallel to Sir Gawain and the Green Knight is the story of original sin in the Garden of Eden. Gawain's temptation correlates to the temptation of Adam, which is rooted in the sins of the flesh. The women in the story seem to accentuate the downfall of Gawain, which mirrors the downfall of Arthur's court, as well as man's fall from grace in the garden. Originally, the first duty of a knight was to be at the service of his church. However, with the rise of courtly love, knights began to give their devotion to their mistress rather than God. This elevated the church's mistrust of women and the flesh. The characterization of Bertilak's wife is not unlike that of Eve, a temptress who would bring both happiness and despair to her man. One interesting twist to this story is that, like courtly love, possession of power seems to be shifted into the hands of the women. The wife of Bertilak operates unassisted against Gawain in the bedroom as the hunter and the aggressor. The great feminine power in the story, however, comes from Morgan le Fay, the evil stepsister of Arthur. She is strong enough to move into Bertilak's castle, turn him green and order him to walk and talk with a severed head. The Virgin Mary also plays a prominent role in the tale. It seems as if Mary and Gawain have a relationship based on a special untainted Christian love. That Gawain is Mary's knight is made clear in the scene where he is robed for battle. 'That all h... ...t. The women in this tale serve as a medium for comparing the spiritual journey of Sir Gawain to the creation myth. With Mary as a symbol of perfection and Lady Bertilak as an Eve-like symbol of temptation, the fact that he is torn between them displays his humanness just as Adam was torn between the word of God and the love of Eve. In this case, Morgan le Fay would probably be considered the serpent in the garden, the instigator of the conflict in the story. Because of the story of Eve, women were frequently looked upon in medieval times as cunning, untrustworthy and generally evil. Women in the story of Sir Gawain and the Green Knight are looked upon with the male concept that flesh is evil and will lead to man's downfall, which is highlighted by the contrast of Courtly love to Christian love. Works Cited Abrams, M.H. 'The Norton Anthology of English Literature.'; New York: W.W. Norton & Company, Inc., 1993. De Roo, Harvey. "Undressing Lady Bertilak: Guilt and Denial in Sir Gawain and the Green Knight." The Chaucer Review 27 (1993): 305-24. Warner, Marina. 'Alone of all Her Sex: The Myth and the Cult of the Virgin Mary';. New York: Alfred A. Knopf, Inc., 1976.

Events Management Report on Fan Expo †Canada Essay

This report has been commissioned by James Armstrong of Hobby Star Marketing to critically analyse and evaluate the Fan Expo Canada event. A general overview of the event will be provided as well as the event category it falls under and the implications of this. The event will then be analysed in terms of its social impact, the stakeholders involved and economic implications. This report is limited to the event information available on the internet and in the prescribed text for theory based arguments. This report aims to advise Hobby Star Marketing on the current and future states of their event and as related to tourism theory, what impact this may have on social and economic factors, as well as impact on event stakeholders as a whole. In conclusion recommendations will be put forward as to the best approach for event organisers to take in the future to ensure all stakeholders are kept satisfied as well as the wider community. 2.0 Description of EventFan Expo Canada is held annually at the end of each summer in Toronto Canada and features three days of non-stop festivities in the areas of video games, anime, science fiction, horror and comic books. The expo has been running for 12 years with its name recently being changed from the Canadian National Expo. Fan Expo is held primarily in the Toronto Metro Convention Centre and last year boasted over 37 000 admissions. Fan Expo is a unique event targeted to a specific range of markets. Having been dubbed in the past the ‘Nerd Prom’, the Fan Expo draws visitors from all around the globe to Toronto Canada, enhancing awareness of the region and its status in gaming, anime, science fiction, horror and comic book realms. Due to these factors it is suitable to classify this expo as a Hallmark event. This type of event is typically defined as a major one time or recurring event of limited duration developed primarily to enhance awareness or appeal and profitability of a tourism destination in the short or long term. In order to obtain success such events rely primarily on their uniqueness, status or timely significance to create both interest and to attract attention (Ritchie, 1984, p.2; Getz 1997 pp.5-6 in Allen et al. 2005). Fan Expo is highly significant to its target markets and provides the host venue, community and destination as a whole with a competitive  advantage over other conven tions of a simular nature in North America (third largest event of its kind in this region) (Hobbystar 2006). 3.0 Social Impact 3.1 Social BenefitsAll events have a direct social and cultural impact on their participants and sometimes on the broader host communities (Hall, 1989; Getz, 1997 in Allen et al. 2005). In terms of the Fan Expo, the social impacts are expansive and many benefits come to fruition as a result of the event taking place. One in particular is the validation of community groups associated with the event. A positive impact can be seen here through the acknowledgment of local comic book artists, with the talents of the normally ostracised minority being recognised and applauded at an international level. As the community is one of the major event stakeholders, not only are these groups validated but further encouragement of community participation also results due to the overwhelming achievements of specific community members. Social constancy and community pride are again other factors that result in benefits to the community of Toronto. Fan Expo brings tourists from all over the world to one epicentre of likeminded people. Through this experience the local community may volunteer and band together to present their city in the greatest state possible to expo visitors. The impact this effect has on the tourists is also significant as it encourages migration attractiveness as well as an increased positive image tourists have about the city of Toronto. This has a two fold effect as the community also notes the economic gain of for example encouraging a major video game expert to relocate to Toronto (stronger and more competitive local economy). In retrospect the community is more socially aware of itself and its visitors and is more likely to retain and develop higher visitor rates due to its strengthened welcoming culture. The convergence of these likeminded industry experts also facilitates an arena for the development of new ideas and partnerships both within the industry and between expo visitors. Tourists that bring already existing ideas to the expo then can have that idea realised through the resources of local and visiting industry experts (i.e. a gaming designer that wants to  sell his or her idea to a major video game corporation). The potential for economic growth due to this convergence is quite extraordinary. 3.2 Social Costs Of the research conducted about what social cost Fan Expo has had to the local community, one common theme that was realised was the apparent facilitation of strongarm tactics. In an overview of what was discovered, local comic book retailers were being forced by expo organisers either feature solely in their expo (not other competing expos) or not feature at all. The local community backlash from this decision was quite significant with many key industry leaders in the community moving to boycott the Fan Expo event. The ramifications of this monopolistic type approach on the community can cause not only resentment towards event participants and tourists, but also commodification of the event because of the lack of attendance of original industry leaders and pioneers (eg. instead of the creator of the comic book ‘The Phantom’ attending in person, Fan Expo constructs a video montage of the comic book creator and his work instead). This can cause dissonance between fans and organisers as what was once expected and a major highlight of the event is now replaced with a display that for most fans, the information presented is not uncommonly found on say the internet. On a whole, community resentment for the event taking place in their city can occur but also tourist resentment for the visiting the destination in the future is also a possibility. Social consequence such as criminal activity may occur as a result, specifically if some visitors have travelled a significant distance to attend the event. 4.0 Stakeholders In regards to the stakeholders for Fan Expo Canada, a number of categories can be used to separate the role and objectives of each. In terms of the host organisation, the Toronto City Council is a major figurehead as the support from local government for funding and other regulatory and staffing concerns is vital to the success of this event. Hobby Star Marketing as a corporation is also another obvious stakeholder as they are the primary event organisers and have substantial amounts of  resources injected into fate of this event. The Toronto Metro Convention Centre is also another key stakeholder as the event is being held at their premise. Their objectives for the event will be to ensure their function areas function as they should throughout the expo as well as working closely with Hobby Star to ensure all logistical requirements are executed without delay or error. Toronto as a community is also a primary stakeholder as its involvement and expectations for the event are additionally significant. For Hobby Star, their understanding of the local community is a key factor for the event to be a success. Specifically in this case, the understanding of local community comic book or gaming groups and societies will enable event organisers to develop the event to cater for the needs of these groups. Furthermore representatives from these groups could provide recommendations and assistance for future event ideas. In doing so the community expectations can be more accurately met and overall dissonance of the event significantly reduced (Allen et al. 2005). In terms of the media, local television, radio and print associations are also termed stakeholders as they have been invested in and have also dedicated resources to either cover the event progress or advertise the event in the weeks leading up. Due to the events widespread appeal, web media would also be considered an important stakeholder as accurate information needs to be communicated to tourists planning on attending. Web media is also important to monitor because as noted earlier, backlash or community opinions are not contained within the community when the web is involved, and negative impacts can occur quickly through use of the internet. Other stakeholders include event staff, volunteers and centre management and staff. Their role is to ensure the event plan is executed effectively and their presence as a required resource must also be nurtured through not only being catered for and looked after during the event, but also recognition for their contributions once the event has ended. One way this is performed is by volunteers being given free access to any event over the three days before and after their allotted shift time (Happy Star 2006). For any event  to be truly effective, the vision and philosophy of the event must be shared by all of the team (Allen et al. 2005). The participants of the event which include guest speakers, retailers, performers, industry professionals and the general public are also significant stakeholders. To make the event memorable and meaningful, the event manager must ensure all of these figureheads are satisfied in terms of what they want to get out of the event, which includes their physical needs of comfort, safety and security. At Fan Expo in 2006, it is the 40th anniversary of the birth of Star Trek and the key guest speakers are two famous stars from the original television series. Their involvement and satisfaction of how the event is run and managed will be reflected on how well they address the audience and subsequently the level of enjoyment the spectators receive. 5.0 Economic Analysis The economic standpoint in regards to events is the make or break factor – events must generate revenue to be successful. Therefore one of the most important impacts is the tourism revenue generated by an event (Allen et al. 2005). External visitors not only spend money on the event itself such as tickets and merchandise but also on items such as travel, accommodation and other goods and services available in the host city. This economic influx is sometimes depended on in many smaller communities however in the case of Toronto, effective tourism can result in visitors that are in town for the event to extend their stay and consequently increase spending (Allen et al. 2005). As described in Section 3.1, many business opportunities are possible through the interaction of local and visiting industry members. Furthermore their interaction with the local community and its economy may also give way for tourists to increase stay or indeed make a bid to stay permanently. For the expo, this could mean opportunities for more qualified industry leaders to be a part of the planning process for the following year’s expo. The overall benefits for Fan Expo could include for example the cast voices for the latest Star Trek game to be sourced and recorded in Toronto due to Microsoft Games setting up headquarters after negotiations. In hindsight whilst the  majority of the Fan Expo is based around a market and display type setup, there are also many exclusive forums and networking conferences that occur over the weekend to further facilitate the creation of business opportunities (Hobby Star 2006). Higher rates of employment can also result from this event – employment requirements for Fan Expo itself but also local industry members showcasing their talents then being offered work at a major firm. This can also have a negative effect as the local talent is snapped up and shipped out to other cities or countries, possibly damaging the part of the local economy they were once involved in. On the other hand if nurtured the community member could leave to gain more knowledge then return to the city, bringing with them a wealth of knowledge and experience that could significantly increase the economy of the city and region. On the agenda of negative economic impacts, opportunity cost can clearly be linked to the issues described in Section 3.2 in regards to strongarm tactics allegedly being used by Hobby Star Marketing. With retailers being forced to choose between festivals, the chance for economic gain is lost. Spectators that cannot attend the Fan Expo are left with no alternatives to view and purchase expo items and retailers in general loose out because of reduced exposure. This consequently forces retailers to ascertain which festival would be more financially beneficial to them, hence reducing exposure and possible loss of business opportunities. As stated in Section 3.2 this can generate a negative reputation for Happy Star and the Fan Expo in general and have many negative social and economic impacts. 6.0 Conclusions This report has provided an overview of the Fan Expo Canada event and classified into the Hallmark event category. The event was then analysed in terms of its social impact, the stakeholders involved and economic implications. This report has found that Fan Expo appeals to a unique market and draws visitors to the town of Toronto. It has outlined relevant stakeholders and their goals and found that increased integration of local community groups with the planning process of the expo could be beneficial to future success and reduced dissonance. This report described the importance of economic planning and how decisions that are made in the best interests of the event may not be in the best interests of the wider community. This report aims to advise Hobby Star Marketing on the current and future states of their event and as related to tourism theory, what impact this may have on social and economic factors, as well as impact on event stakeholders as a whole. In conclusion recommendations will be put forward as to the best approach for event organisers to take in the future to ensure all stakeholders are kept satisfied as well as the wider community. 7.0 Recommendations In hindsight to this report, the following recommendations are made:Increase communication with community industry leaders to ascertain the best approach in organising the event so maximum exposure can be generated. Further develop networking events at the expo and facilitate the creation of business opportunities and discovery of new talent in the local community. Promote to industry leaders the benefits of setting up operations in the community and tie this in with a major showcasing of their products at the following years expo. Work closer with Toronto City Council to further promote local and regional tourism to increase longer stays and increased economic activity. Reduce dissonance by operating competitively and ethically with other expos. List of References Allen, J O’Toole, W Harris, R McDonnell, I 2005, Festival and Special Event Management, John Wiley & Sons, Milton. Hobby Star 2006, Fan Expo Canada, viewed 20 August 2006, Getz, D 1997, Event Management and Event Tourism, Cognizant Communication Corporation, New York. Wikimedia Foundation 2006, Fan Expo Canada, viewed 6 August 2006,

Inspiring and Celebratory 40th Birthday Quotes

Your 40th birthday welcomes you into grand middle age—or as some like to think of it, the sweet spot. This decade doesnt have the casual immaturity of youth, nor does it have the constant dependency of old age. Gone are the days when you are busy settling in your marriage or career, and youve long said goodbye to the angst-filled teenage years and the roller-coaster ride of your twenties. At forty, you have earned your place in the sun. You have carved yourself a niche and established your identity. Enjoy your fortieth turn around the sun in quiet reflection on four decades of a beautiful life, starting with these age-appropriate quotes. Famous Quotes About Turning 40 Benjamin FranklinAt twenty years of age, the will reigns; at thirty, the wit; and at forty, the judgment. Helen RowlandWhat most persons consider as virtue, after the age of 40 is simply a loss of energy. AnonymousAt the age of twenty, we dont care what the world thinks of us; at thirty, we worry about what it is thinking of us; at forty, we discover that it wasnt thinking of us at all. Arthur SchopenhauerThe first forty years of life give us the text: the next thirty supply the commentary. Helen RowlandLife begins on your 40th birthday. But so do fallen arches, rheumatism, faulty eyesight, and the tendency to tell a story to the same person, three or four times. George Bernard ShawEvery man over forty is a scoundrel. Edward YoungBe wise with speed; a fool at forty is a fool indeed. French ProverbForty is the old age of youth; fifty is the youth of old age. CiceroThis wine is forty years old. It certainly doesnt show its age.(Latin: Hoc vinum Falernum annorum quadragenta est. Bene aetatem fert.) Colleen McCulloughThe lovely thing about being forty is that you can appreciate twenty-five-year-old men. Maya AngelouWhen I passed forty I dropped pretense, cause men like women who got some sense. Laura RandolphIf life really begins on your 40th birthday, its because thats when women finally get it†¦ the guts to take back their lives. James ThurberWomen deserve to have more than twelve years between the ages of twenty eight and forty. Samuel BeckettTo think, when one is no longer young, when one is not yet old, that one is no longer young, that one is not yet old, that is perhaps something. W.  B. PitkinLife begins at forty.

Ceiba Was the Maya Symbol of the Universe

The Brutality, Injustice, and Institution of Slavery is...

The Brutality, Injustice, and Institution of Slavery is Wrong in any Age The idea and horrendous act of one human owning another is a plague etched in history from the colonization of the New World to its abolishment during the Civil War. The exemplification being referenced is slavery. Slavery placed man-kind in a position of power where the depravity of personal liberties and rights were not only apparent but generally accepted. There was an ideology that slaves were less than human; their species classified as property and could be treated as such. Slaves were bred as selectively as animals, tamed, disciplined, transported, and exploited in the same manner. There are two individual perspectives of slavery from varying timelines,†¦show more content†¦This was a turning point in his life where renouncing the encomienda, or legal system justifying the occupation of natives under Spanish rule (Encomienda) became paramount. His political ventures began in the year 1515 w here the Spanish government allocated him authority to establish a colony off the Venezuelan coast where the alleviation of the natives suffering and exploitation could begin (Baym 39). At this juncture in his fight to end slavery, some countermeasures were presented. One of which was the importation of African slaves to ease Indian suffering. This idea was not conducive to Casas’ cause and he soon redacted it. As stated in Casas History of the Indies, â€Å"black slavery was as unjust as Indian slavery, and was no remedy at all† (Las Casas). In this instance, Casas was aware of the injustice of slavery no matter the person. He constant debates and attempted compromises culminated in the failure of the Venezuelan venture. The continued violence and brutal acts toward slaves discouraged Casas into anonymity until he decided that if he cannot end slavery, he could at least become an advocate against the cruel and inhumane treatment of slaves. He continued this e ndeavor while combating allegations of treason and heresy until his death. Las Casas perspective of slavery was one of participation, observation, morality, realization, and change. Olaudah Equino’s perspective, on theShow MoreRelatedIt Matters Not, The Brutality, Injustice, and Institution of Slavery is Wrong in any Age The idea500 Words   |  2 PagesIt Matters Not, The Brutality, Injustice, and Institution of Slavery is Wrong in any Age The idea and horrendous act of one human owning another is a plague etched in history from the colonization of the New World to its abolishment during the Civil War. The exemplification being referenced is slavery. 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Method For Characterisation Of Laser Beams Engineering Essay Free Essays

Particularly in the field of optical maser direct authorship lithography it is necessary to derive exact cognition about the form and features of the used optical maser beam, whilst a homogenous power distribution is an indispensable parametric quantity for qualitatively good and consistent consequences in surface structuring. Several â€Å" classical † methods in word picture of optical maser beams are already applied, such as: Knife border method Slit method Pinhole method CCD camera method These techniques will be shortly explained in subdivision 2. In fact, a optical maser beam ( â€Å" standard TEM00 † ) fades bit by bit, due to its Gaussian profile ( Figure 1 ) . We will write a custom essay sample on Method For Characterisation Of Laser Beams Engineering Essay or any similar topic only for you Order Now Therefore it is necessary to find what is known as the Centre of the beam. Chapple [ 1 ] describes the strength profile I ( x, y ) as follows: where ten and Y are the cross Cartesian co-ordinates of any point, x0 and y0 mark the Centre of the beam and R is the 1/e2 radius. This definition is frequently used in theory. McCally [ 2 ] defines the Gaussian distribution of the strength I ( x, y ) by agencies of the beam radius R belonging to the 1/e irradiance shown in Figure 1 ( left ) . The emitted power of the optical maser beginning can be determined by incorporating the irradiance ( I ) , severally the optical strength I ( x, y ) , over the affected cross sectional country A: 2. Techniques of beam profiling Knife border method To derive information about the power distribution across a cross sectional plane of a optical maser beam, the use of the knife border method is the most simple attack. Thereby, a crisp edged home base, e.g. a razor blade, is ab initio covering the whole optical maser beam in forepart of a power metre for continues wave radiation or an energy metre for pulse operation. By precise line wise supplanting of the knife border mounted on a additive motion phase, more and more optical maser radiation reaches the detector unit, until the whole beam is covering the feeling country. Figure 1 ( right ) shows the consequence of this measurement process: Due to the motion of the knife edge the value of the detected power additions steadily. The derived function of this power map P ( x, Y ) yields the two dimensional Gaussian profile of the power distribution across the optical maser beam ( Figure 1, left ) . Slit method A 2nd possibility to find the power distribution within a optical maser beam is similar to the knife border method: Alternatively of a crisp edged home base, a really narrow slit is step by step moved across the optical maser beam. As a stipulation for valid measurings the gap of the slit has to be smaller than the diameter of the considered beam is. Typically this gap is in the scope of some micrometers. Drawbacks of â€Å" traditional methods † The knife edge- every bit good as the slit method offer merely a limited measure of beam features: local â€Å" hot-spots † , i.e. countries of superior power, are undetectable due to the incorporating measurement rule. However this method is suited for speedy measurings to find the diameter and the class strength profile of the considered optical maser beam. Pinhole method This method measures the strength of irradiance through a really little hole in a home base ( pinhole ) confronting the optical maser beam. The strength of light go throughing through this pinhole is instead low, so that a photomultiplier tubing ( PMT ) has to be used to observe the irradiance. Due to the feature of a PMT, e.g. its comparatively low signal to resound ration ( SNR ) , the collected informations are corrugated. However the strength distribution can be achieved within a local declaration of about 3micron by using a Gaussian tantrum. Therefore by transversal scanning across a optical maser beam, a high declaration image of the power distribution within the beam can be gained. Hot musca volitanss are noticeable and more elaborate characteristics can be located. CCD Camera method Differing from the scanning methods described above, the use of CCD ( Charge-coupled Device ) cameras for the review of optical maser musca volitanss will give a really speedy feeling of the power distribution within the beam by merely a â€Å" individual shooting † . The quality of the image, e.g. the declaration, is straight depending on size and figure of pels on the CCD-Sensor-chip. Typically the pel size is in the scope of 6 microns2, linked to a entire figure of pels in the scope of 1 to 2 mega pels. By utilizing this method it must be noted, that dust and other drosss on the CCD bit can ensue in image deformation and/or misinterpretable beam characteristics. Furthermore, attention must be taken non to destruct the CCD bit by the incident optical maser beam. 3. Beam word picture by agencies of optical fibers tips To get the better of the limited declaration of the CCD- and pinhole method, severally, a new strength profile measuring technique has been developed. Similar to the pinhole method described above, an optical fiber tip with an aperture of a few 100 nanometer is applied to roll up light by scanning across a optical maser beam transversely. A photomultiplier tubing ( PMT ) attached at the out-coupling terminal of the fiber detects the gathered visible radiation during the scanning procedure so that a two-dimensional image of the strength distribution can be evaluated. By altering the sidelong place of the fibre tip, multiple cross sectional planes can be scanned, taking to a three-dimensional image of the strength distribution e.g. within a focussed optical maser beam. 3.1 Near-field matching into the optical fiber â€Å" Classical † attacks to picture the incoupling of visible radiation into the fibre tip fail, due to the really little gap of the fibre tip ( aperture ) , in the scope of some hundred nanometers, which is considerable smaller than the wavelength of the optical maser visible radiation within the focal point. Due to this really little gap, one can speak about the so called â€Å" close field † To derive information arising from the close field and to transport this information into the far field, it is necessary to transform the evanescent Fieldss into propagating Fieldss. This could be done by seting a Centre of dispersing, in this instance the really narrow tip, into the close field. Thereby dipole- oscillations are generated at the boundary of this tip by agencies of the evanescent field ( Figure 2 ) . With: I µ0= vacuity permittivity ; =unit vector ; = wave vector: 2/ I » ; I†°= angular frequence of the oscillation and utilizing the dipole-moment: With: a=diameter of the gap ; I µr=relative permittivity The undermentioned footings for the far field ( R lt ; lt ; I »/2 ) and the close field ( R gt ; gt ; I »/2 ) can be derived, and one gets not-propagating every bit good as propagating field constituents: Respectively: The propagating field is straight linked to the close field and can be detected afar. The simulation of the electrical field generated by a plane moving ridge of 1 V/m, heading to a fibre tip, is shown in Fig 3. Based on an optical power of 10mW dispersed on an country of 1 square micrometer, ( which is a instead large country ) , one get by utilizing: with: I= Optical Intensity ; S=Pointing vector ; v=velocity ; E0=electrical field ; D0= electric initiation denseness ; n= index of refraction ( here air: 1.0 ) ; I µ0= vacuity permittivity ( rounded: 10-11 F/m ) = 1010 V/m It has to be noted that the field within the tip is exponentially diminishing ( refer to formula N ) and by this merely a really little portion of the generated electrical field, in this illustration 5*1010 V/m straight at the tip, can be detected at the out matching terminal of the fiber by the PMT. 3.2 Apparatus The PI P-854.00 piezoelectric actuator used in this apparatus has a displacement scope of 25A µm for all right placement and can besides be pre-positioned by a micrometer-screw more approximately. The sensing of gathered visible radiation is done by a Hamamatsu H5784 type photomultiplier tubing ( PMT ) with an E5776 FC type adapter attached ( Figure 4 ) A fibre holder mounted to the piezoelectric actuator is used to take and protect the optical fiber tip during the scanning procedure. After elaboration ( x10 by transimpedance amplifier phase ) and filtering of the gathered strength informations it is converted into digital informations by agencies of a National Instruments 6025e PCI interface card. 3.3 Fibre tip production For this application the optical fiber type used to bring forth the tips is a individual manner fiber manufactured by Newport. Its cut-off wavelength is optimised for the usage of optical masers in the wavelength scope of 400nm -500nm. There are two possibilities to develop the conelike tip of an optical fiber harmonizing to the petitions of a Scaning close field optical lithography ( SNOL ) – fibre tip: The optical fiber tip can be realised by: Pulling methods Chemical etching During the pulling process the optical fiber is preloaded before it is heated up locally with a CO2-laser or a heating-film and forced to run. As the thaw procedure begins, the puller stretches the optical fiber with extra force apart, so that the fiber is tapert first and eventually cryings itself bring forthing two tips. The belongingss of the optical fiber tips produced this manner vary on the different parametric quantities of the puller – as for illustration the drawing force. Normally, all pulled SNOL-tips show a really thin geometry ( e.g. Figure 4, left ) . This is particularly disadvantageous for the considered application, because this thin construction tends to flex and hover. More stiff fibers, which have tips with higher cone angle, are more suited Furthermore, these fibers tips feature a really little transmittal of 10-5 to 10-6 due to the long form of the tip, in which the visible radiation is evanescent ( exponentially diminishing ) . Larger cone angles and correspondingly a higher transmittal up to 10-2 is reached by engraved SNOL- fiber tips as used in this work. Several etching methods exist to bring forth fibre tips. The process used here is the so called â€Å" tube-etching † . After cleansing of the optical fiber by agencies of ethyl alcohol, the fiber is immersed into hydrofluoric acid. ( Figure 5 ) The undermentioned chemical reactions take topographic point to the Si contained in the fiber – and/or with the Ge at doped fibers: Tube-Etching is a farther development of the standard etching-method, invented by Turner in 1984, published by Stoeckel et Al. and Lambelet et Al. [ 4, 5, 6 ] This process improves the production of well smoother tip surfaces. At the tube-Etching process the coating of the optical fiber is non removed before the etching procedure. Due to gravity drawn debasement of the glass merchandises, a concentration incline arises in the hydrofluoric acid, which causes convection. The convection carries the hydrofluoric acid into the upper zone of the tip that develops therefore conically. To forestall corrosion by hydrofluoric acid exhausts at the upper parts the fiber, a light mineral oil was used as a dissolver to gain a separate stage above the hydrofluoric acid. The temperature during the production of the tips corresponded to room temperature. By completion of the tube-etching procedure the coating of the optical fiber is removed by dichlorine methane and the tip can be metallized, go forthing a little aperture. 4. Consequences A trial rig has been build utilizing optical fiber tips for automized three-dimensional strength profile scanning ( Figure 3 ) . With this it is possible to derive information about the spacial power distribution within optical maser beams. Due to the little aperture of the fiber tip even really little focal parts can be profiled with high local declaration. Corresponding package was developed to command the traveling x-y phase, every bit good as the omega actuator automatically utilizing LabviewA © . Therefore, it is possible to scan across the optical maser beam tomographically, while roll uping strength informations. The information can either be displayed or visualised by agencies of the scanning package itself. Using a new developed package based on OpenGlA © , the strength informations can be displayed in a 3 dimensional image ( Figure 7 ) with the chance to revolve the way of position in all grades of freedom. Furthermore, different mathematical filters can be applied to better image quality. By scanning more transverse sectional planes, individual pieces can be shown in an â€Å" overlayed † manner, to detect the focal point â€Å" traveling † due to the sidelong alteration of the fibre tip ( Figure 8 ) 3. Decision A fresh method for high deciding beam word picture particularly for little aperture optical masers has been described. With this automized 3- dimensional series scanning method it is possible to derive information about the spacial power distribution within a optical maser topographic point. 4. Figures / Artwork Figure 1: [ left ] Theoretical power distribution within a TEM 00 optical maser beam can be described by a Gaussian profile [ right ] Integrated optical maser power measured with the knife border method as a map of the cross sectional co-ordinate ten. Figure 2: [ left ] E-field in the close field of the tip when illuminated by plane moving ridge with field strength of 1 V/m, polarised along the axes of the tip [ right ] Cross-sectional position of an optical fiber tip with an cone angle † I? † and an radius from the aperture rim † R † .The associated electric field lines are plotted in logarithmic mode [ 3 ] Figure 3: Principle and image of the apparatus for high deciding optical maser beam profiling Figure 4: Comparison of a fibre tip produced by the drawing method [ left ] and a fibre tip produced by etching [ right ] Figure 5: Conventional representation of the aˆztube- etching method † Figure 6: [ left ] Fibre tip generated by the etching method after 60min etching clip ( delight mention to Figure 4 â€Å" B † ) [ right ] Fibre tip generated by the etching method after 120min etching clip ( delight mention to Figure 4 â€Å" degree Celsiuss † ) Figure 7: Beam profile of a DVD optical pickup unit ( OPU ) gained with the fiber tip based system ( declaration: 150nm ) Figure 8: [ left ] 12- measure sidelong scan through a ( TEM00 ) optical maser focal point of a DVD optical pickup unit ( OPU ) gained with the fiber tip based system ( cross position ) [ right ] ( sidelong position ) 5 Literatures: [ 1 ] Chapple, P.B. , ( 1994 ) , Beam waist and M2 measuring utilizing a finite slit, Opt. Eng. , 33, 2461-2466 [ 2 ] McCally, R.L. , ( 1984 ) Measurement of Gaussian beam parametric quantities, Appl. Opt. , 23, 2227 [ 3 ] Drezet, A. , Nasse, M.J. , Huant, S. , Woehl, J.C. , ( 2004 ) , The optical near-field of an aperture tip ; Europhys. Lett. , 66 ( 1 ) , 41-47 [ 4 ] Stockle, R. , Fokas, C. , Deckert, V. , Zenobi, R. , Sick, B. , Hecht, B. , Wild, U.P. , ( 1999 ) , High quality near field optical investigations by tubing etching, Applied Physics Letters, 75 ( 2 ) , 160-2 [ 5 ] Lambelet, P. , Sayah, A. , Pfeffer, M. , Philipona, C. , Marquis Weible, F. , ( 1998 ) , Chemically etched fiber tips for close field optical microscopy: a procedure for smoother tips, Applied Optics, 37 ( 31 ) , 7289-7292 [ 6 ] Suh, Y. , Zenobi, R. , ( 2000 ) , Improved Probes for Scaning Near Field Optical Microscopy, Advanced Materials, 12 ( 15 ) , 1139-1142 6.0 Keywords: Near field, far field, optical maser beam, focal point, focal plane, fibre tip, pinhole, knife border 7.0 Terminology: I= Intensity [ W/m ] P=Power [ W ] A=Area [ m^2 ] I »=Wavelength [ m ] E=Energy [ W/s ] I µ= Vacuum permittivity [ A2A ·s4A ·kg-1A ·m-3 ] I µr=Relative permittivity [ A2A ·s4A ·kg-1A ·m-3 ] =Unit vector =Wave vector: 2/ I » t=Time [ s ] I†°= Angular frequence of the oscillation [ s-1 ] =Dipole-moment [ AA ·m2 ] a=Diameter of the gap [ m ] How to cite Method For Characterisation Of Laser Beams Engineering Essay, Essay examples

Week 4 Discussion Questions free essay sample

Week 4 Discussion Questions †¢What are main elements in calculating the cost of capital? How does an increase in debt affect it? How do you identify an organization’s optimal cost of capital? †¢The main elements in calculating the cost of capital are cost of debt, cost of equity, preferred stock and common stock. †¢An increase in debt indicates a higher risk which can increase the required rate of return which raises the cost of capital. Higher debt can also accrue additional costs. †¢By mixing the permanent sources of funds used by the organization that will maximize their common stock price or searching for the funds mix that will minimize the organization’s composite cost of capital. †¢What is meant by WACC? What are some components of WACC? Why is WACC a more appropriate discount rate when doing capital budgeting? What is the effect on WACC when an organization raises long-term capital? WACC stands for the weighted average cost of capital which is a weighted average of all costs incurred by the organization. We will write a custom essay sample on Week 4 Discussion Questions or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page †¢Some of the components of WACC are various sources of capital such as bonds, preferred stock, and common equity, including retained earnings. †¢WACC is a more appropriate discount rate when doing capital budgeting because it uses after tax costs and the weights show the entire amount of financing on a percentage level. This gives the company the knowledge of what rate of return it needs to satisfy stockholders and creditors. †¢Raising long term capital leaves a chance for rates of maturity to change making the company look for risk free rates. The company would need to make sure they can meet the risk and the changing required rate of return as well as the changing rates that affect costs and fees. †¢What is an IPO? How does an IPO allow an organization to grow financially? When is a merger or an acquisition, instead of an IPO, more appropriate? An IPO stands for Initial Public offering. It is the first time a company’s stock is sold to the public. †¢An IPO opens them up to investors and trading on the secondary market. It raises new capital and provides liquidity. †¢When companies need to join forces to grow and avoid certain costs associated with IPO’s which can be quite large. This is more for companies that are not big enough but want a quick growth or for comp anies that cannot afford to take on too much risk.