Creative Writing Essay

Specific poetic forms have been developed by many cultures. In more developed, closed or â€Å"received† poetic forms, the rhyming scheme, meter and other elements of a poem are based on sets of rules, ranging from the relatively loose rules that govern the construction of an elegy to the highly formalized structure of the ghazal or villanelle. Described below are some common forms of poetry widely used across a number of languages. Additional forms of poetry may be found in the discussions of poetry of particular cultures or periods and in the glossary. Sonnet Among the most common forms of poetry through the ages is the sonnet, which by the 13th century was a poem of fourteen lines following a set rhyme scheme and logical structure. By the 14th century, the form further crystallized under the pen of Petrarch, whose sonnets were later translated in the 16th century by Sir Thomas Wyatt, who is credited with introducing the sonnet form into English literature. A sonnet’s first four lines typically introduce the topic. A sonnet usually follows an a-b-a-b rhyme pattern. The sonnet’s conventions have changed over its history, and so there are several different sonnet forms. Traditionally, in sonnets English poets use iambic pentameter, the Spenserian and Shakespearean sonnets being especially notable. In the Romance languages, the hendecasyllable and Alexandrine are the most widely used meters, though the Petrarchan sonnet has been used in Italy since the 14th century. Sonnets are particularly associated with love poetry, and often use a poetic diction heavily based on vivid imagery, but the twists and turns associated with the move from octave to sestet and to final couplet make them a useful and dynamic form for many subjects.] Shakespeare’s sonnets are among the most famous in English poetry, with 20 being included in the Oxford Book of English Verse. Shi (poetry) Shi (traditional Chinese: è © ©; simplified Chinese: è ¯â€"; pinyin: shÄ «; Wade-Giles: shih) Is the main type of Classical Chinese poetry.Within this form of poetry the most important variations are â€Å"folk song† styled verse (yuefu), â€Å"old style† verse (gushi), â€Å"modern style† verse (jintishi). In all cases, rhyming is obligatory. The Yuefu is a folk ballad or a poem written in the folk ballad style, and the number of lines and the length of the lines could be irregular. For the other variations of shi poetry, generally either a four line (quatrain, or jueju) or else an eight line poem is normal; either way with the even numbered lines rhyming. The line length is scanned by according number of characters (according to the convention that one character equals one syllable), and are predominantly either five or seven characters long, with a caesura before the final three syllables. The lines are generally end-stopped, considered as a series of couplets, and exhibit verbal parallelism as a key poetic device. ]The â€Å"old style† verse (gushi) is less formally strict than the jintishi, or regulated verse, which, despite the name â€Å"new style† verse actually had its theoretical basis laid as far back to Shen Yue, in the 5th or 6th century, although not considered to have reached its full development until the time of Chen Zi’ang (661-702) A good example of a poet known for his gushi poems is Li Bai. Among its other rules, the jintishi rules regulate the tonal variations within a poem, including the use of set patterns of the four tones of Middle Chinese The basic form of jintishi (lushi) has eight lines in four couplets, with parallelism between the lines in the second and third couplets. The couplets with parallel lines contain contrasting content but an identical grammatical relationship between words. Jintishi often have a rich poetic diction, full of allusion, and can have a wide range of subject, including history and politics. One of the masters of the form was Du Fu, who wrote during the Tang Dynasty (8th century). Villanelle The villanelle is a nineteen-line poem made up of five triplets with a closing quatrain; the poem is characterized by having two refrains, initially used in the first and third lines of the first stanza, and then alternately used at the close of each subsequent stanza until the final quatrain, which is concluded by the two refrains. The remaining lines of the poem have an a-b alternating rhyme.The villanelle has been used regularly in the English language since the late 19th century by such poets as Dylan Thomas, W. H. Auden,and Elizabeth Bishop. Tanka Tanka is a form of unrhymed Japanese poetry, with five sections totalling 31 onji (phonological units identical to morae), structured in a 5-7-5 7–7 pattern.There is generally a shift in tone and subject matter between the upper 5-7-5 phrase and the lower 7-7 phrase. Tanka were written as early as the Nara period by such poets as Kakinomoto no Hitomaro, at a time when Japan was emerging from a period where much of its poetry followed Chinese form. Tanka was originally the shorter form of Japanese formal poetry, and was used more heavily to explore personal rather than public themes. By the 13th century, tanka had become the dominant form of Japanese poetry, and it is still widely written today. Haiku Haiku is a popular form of unrhymed Japanese poetry, which evolved in the 17th century from the hokku, or opening verse of a renku. Generally written in a single vertical line, the haiku contains three sections totalling 17 onji, structured in a 5-7-5 pattern. Traditionally, haiku contain a kireji, or cutting word, usually placed at the end of one of the poem’s three sections, and a kigo, or season-word. The most famous exponent of the haiku was Matsuo BashÃ…  (1644–1694). An example of his writing: Ã¥ ¯Å'Ã¥ £ «Ã£  ®Ã© ¢ ¨Ã£â€šâ€žÃ¦â€°â€¡Ã£  «Ã£  ®Ã£ â€ºÃ£  ¦Ã¦ ±Å¸Ã¦Ë† ¸Ã¥Å"Ÿç” £ fuji no kaze ya oogi ni nosete Edo miyage the wind of Mt. Fuji I’ve brought on my fan! a gift from Edo Ode Odes were first developed by poets writing in ancient Greek, such as Pindar, and Latin, such as Horace. Forms of odes appear in many of the cultures that were influenced by the Greeks and Latins.The ode generally has three parts: a strophe, an antistrophe, and an epode. The antistrophes of the ode possess similar metrical structures and, depending on the tradition, similar rhyme structures. In contrast, the epode is written with a different scheme and structure. Odes have a formal poetic diction, and generally deal with a serious subject. The strophe and antistrophe look at the subject from different, often conflicting, perspectives, with the epode moving to a higher level to either view or resolve the underlying issues. Odes are often intended to be recited or sung by two choruses (or individuals), with the first reciting the strophe, the second the antistrophe, and both together the epode.Over time, differing forms for odes have developed with considerable variations in form and structure, but generally showing the original influence of the Pindaric or Horatian ode. One non-Western form which resembles the ode is the qasida in Persian poetry. Ghazal The ghazal (also ghazel, gazel, gazal, or gozol) is a form of poetry common in Arabic, Persian, Turkish, Azerbaijani, Urdu and Bengali poetry. In classic form, the ghazal has from five to fifteen rhyming couplets that share a refrain at the end of the second line. This refrain may be of one or several syllables, and is preceded by a rhyme. Each line has an identical meter. The ghazal often reflects on a theme of unattainable love or divinity. As with other forms with a long history in many languages, many variations have been developed, including forms with a quasi-musical poetic diction in Urdu. Ghazals have a classical affinity with Sufism, and a number of major Sufi religious works are written in ghazal form. The relatively steady meter and the use of the refrain produce an incantatory effect, which complements Sufi mystical themes well. Among the masters of the form is Rumi, a 13th-century Persian poet who lived in Konya, in present-day Turkey. Genres In addition to specific forms of poems, poetry is often thought of in terms of different genres and subgenres. A poetic genre is generally a tradition or classification of poetry based on the subject matter, style, or other broader literary characteristics. Some commentators view genres as natural forms of literature. Others view the study of genres as the study of how different works relate and refer to other works. Narrative poetry Narrative poetry is a genre of poetry that tells a story. Broadly it subsumes epic poetry, but the term â€Å"narrative poetry† is often reserved for smaller works, generally with more appeal to human interest. Narrative poetry may be the oldest type of poetry. Many scholars of Homer have concluded that his Iliad and Odyssey were composed from compilations of shorter narrative poems that related individual episodes. Much narrative poetry—such as Scottish and English ballads, and Baltic and Slavic heroic poems—is performance poetry with roots in a preliterate oral tradition. It has been speculated that some features that distinguish poetry from prose, such as meter, alliteration and kennings, once served as memory aids for bards who recited traditional tales. Notable narrative poets have included Ovid, Dante, Juan Ruiz, Chaucer, William Langland, Luà ­s de Camà µes, Shakespeare, Alexander Pope, Robert Burns, Fernando de Rojas, Adam Mickiewicz, Alexander Pushkin, Edgar Allan Poe and Alfred Tennyson. Epic poetry Epic poetry is a genre of poetry, and a major form of narrative literature. This genre is often defined as lengthy poems concerning events of a heroic or important nature to the culture of the time. It recounts, in a continuous narrative, the life and works of a heroic or mythological person or group of persons.] Examples of epic poems are Homer’s Iliad and Odyssey, Virgil’s Aeneid, the Nibelungenlied, Luà ­s de Camà µes’ Os Lusà ­adas, the Cantar de Mio Cid, the Epic of Gilgamesh, the Mahabharata, Valmiki’s Ramayana, Ferdowsi’s Shahnama, Nizami (or Nezami)’s Khamse (Five Books), and the Epic of King Gesar. While the composition of epic poetry, and of long poems generally, became less common in the west after the early 20th century, some notable epics have continued to be written. Derek Walcott won a Nobel prize to a great extent on the basis of his epic, Omeros. Verse drama and dramatic verse, Theatre of ancient Greece, Sanskrit drama, Chinese Opera, and Noh Dramatic poetry is drama written in verse to be spoken or sung, and appears in varying, sometimes related forms in many cultures. Greek tragedy in verse dates to the 6th century B.C., and may have been an influence on the development of Sanskrit drama, just as Indian drama in turn appears to have influenced the development of the bianwen verse dramas in China, forerunners of Chinese Opera.East Asian verse dramas also include Japanese Noh. Examples of dramatic poetry in Persian literature include Nizami’s two famous dramatic works, Layla and Majnun and Khosrow and Shirin, Ferdowsi’s tragedies such as Rostam and Sohrab, Rumi’s Masnavi, Gorgani’s tragedy of Vis and Ramin, and Vahshi’s tragedy of Farhad. Satirical Poetry Poetry can be a powerful vehicle for satire. The Romans had a strong tradition of satirical poetry, often written for political purposes. A notable example is the Roman poet Juvenal’s satires.[128] The same is true of the English satirical tradition. John Dryden (a Tory), the first Poet Laureate, produced in 1682 Mac Flecknoe, subtitled â€Å"A Satire on the True Blue Protestant Poet, T.S.† (a reference to Thomas Shadwell).Another master of 17th-century English satirical poetry was John Wilmot, 2nd Earl of Rochester.Satirical poets outside England include Poland’s Ignacy Krasicki, Azerbaijan’s Sabir and Portugal’s Manuel Maria Barbosa du Bocage. Lyric poetry Lyric poetry is a genre that, unlike epic and dramatic poetry, does not attempt to tell a story but instead is of a more personal nature. Poems in this genre tend to be shorter, melodic, and contemplative. Rather than depicting characters and actions, it portrays the poet’s own feelings, states of mind, and perceptions.Notable poets in this genre include John Donne, Gerard Manley Hopkins, and Antonio Machado. Elegy An elegy is a mournful, melancholy or plaintive poem, especially a lament for the dead or a funeral song. The term â€Å"elegy,† which originally denoted a type of poetic meter (elegiac meter), commonly describes a poem of mourning. An elegy may also reflect something that seems to the author to be strange or mysterious. The elegy, as a reflection on a death, on a sorrow more generally, or on something mysterious, may be classified as a form of lyric poetry. Notable practitioners of elegiac poetry have included Propertius, Jorge Manrique, Jan Kochanowski, Chidiock Tichborne, Edmund Spenser, Ben Jonson, John Milton, Thomas Gray, Charlotte Turner Smith, William Cullen Bryant, Percy Bysshe Shelley, Johann Wolfgang von Goethe, Evgeny Baratynsky, Alfred Tennyson, Walt Whitman, Louis Gallet, Antonio Machado, Juan Ramà ³n Jimà ©nez, William Butler Yeats, Rainer Maria Rilke, and Virginia Woolf. Fable The fable is an ancient literary genre, often (though not invariably) set in verse. It is a succinct story that features anthropomorphized animals, plants, inanimate objects, or forces of nature that illustrate a moral lesson (a â€Å"moral†). Verse fables have used a variety of meter and rhyme patterns. Notable verse fabulists have included Aesop, Vishnu Sarma, Phaedrus, Marie de France, Robert Henryson, Biernat of Lublin, Jean de La Fontaine, Ignacy Krasicki, Fà ©lix Marà ­a de Samaniego, Tomà ¡s de Iriarte, Ivan Krylov and Ambrose Bierce. Prose poetry Prose poetry is a hybrid genre that shows attributes of both prose and poetry. It may be indistinguishable from the micro-story (a.k.a. the â€Å"short short story†, â€Å"flash fiction†). While some examples of earlier prose strike modern readers as poetic, prose poetry is commonly regarded as having originated in 19th-century France, where its practitioners included Aloysius Bertrand, Charles Baudelaire, Arthur Rimbaud and Stà ©phane Mallarmà ©.Since the late 1980s especially, prose poetry has gained increasing popularity, with entire journals, such as The Prose Poem: An International Journal,Contemporary Haibun Onlinedevoted to that genre. Speculative poetry Speculative poetry, also known as fantastic poetry, (of which weird or macabre poetry is a major subclassification), is a poetic genre which deals thematically with subjects which are ‘beyond reality’, whether via extrapolation as in science fiction or via weird and horrific themes as in horror fiction. Such poetry appears regularly in modern science fiction and horror fiction magazines. Edgar Allan Poe is sometimes seen as the â€Å"father of speculative poetry†.

Synchronous Motor

Chapter (11) Synchronous Motors Introduction It may be recalled that a d. c. generator can be run as a d. c. motor. In like manner, an alternator may operate as a motor by connecting its armature winding to a 3-phase supply. It is then called a synchronous motor. As the name implies, a synchronous motor runs at synchronous speed (Ns = 120f/P) i. e. , in synchronism with the revolving field produced by the 3-phase supply. The speed of rotation is, therefore, tied to the frequency of the source.Since the frequency is fixed, the motor speed stays constant irrespective of the load or voltage of 3phase supply. However, synchronous motors are not used so much because they run at constant speed (i. e. , synchronous speed) but because they possess other unique electrical properties. In this chapter, we shall discuss the working and characteristics of synchronous motors. 11. 1 Construction A synchronous motor is a machine that operates at synchronous speed and converts electrical energy into mechanical energy. It is fundamentally an alternator operated as a motor.Like an alternator, a synchronous motor has the following two parts: (i) a stator which houses 3-phase armature winding in the slots of the stator core and receives power from a 3-phase supply [See (Fig. (11. 1)]. (ii) a rotor that has a set of salient poles excited by direct current to form alternate N and S poles. The exciting coils are connected in series to two slip rings and direct current is fed into the winding from an external exciter mounted on the rotor shaft. The stator is wound for the same number of poles as the rotor poles.As in the case of an induction motor, the number of poles determines the synchronous speed of the motor: Fig. (11. 1) 293 Synchronous speed, N s = where 120f P f = frequency of supply in Hz P = number of poles An important drawback of a synchronous motor is that it is not self-starting and auxiliary means have to be used for starting it. 11. 2 Some Facts about Synchronous Motor Some salient features of a synchronous motor are: (i) A synchronous motor runs at synchronous speed or not at all. Its speed is constant (synchronous speed) at all loads. The only way to change its speed is to alter the supply frequency (Ns = 120 f/P). ii) The outstanding characteristic of a synchronous motor is that it can be made to operate over a wide range of power factors (lagging, unity or leading) by adjustment of its field excitation. Therefore, a synchronous motor can be made to carry the mechanical load at constant speed and at the same time improve the power factor of the system. (iii) Synchronous motors are generally of the salient pole type. (iv) A synchronous motor is not self-starting and an auxiliary means has to be used for starting it. We use either induction motor principle or a separate starting motor for this purpose.If the latter method is used, the machine must be run up to synchronous speed and synchronized as an alternator. 11. 3 Operating Principle The fact that a synchronous motor has no starting torque can be easily explained. (i) Consider a 3-phase synchronous motor having two rotor poles NR and SR. Then the stator will also be wound for two poles NS and SS. The motor has direct voltage applied to the rotor winding and a 3-phase voltage applied to the stator winding. The stator winding produces a rotating field which revolves round the stator at synchronous speed Ns(= 120 f/P).The direct (or zero frequency) current sets up a two-pole field which is stationary so long as the rotor is not turning. Thus, we have a situation in which there exists a pair of revolving armature poles (i. e. , NS ? SS) and a pair of stationary rotor poles (i. e. , NR ? SR). (ii) Suppose at any instant, the stator poles are at positions A and B as shown in Fig. (11. 2 (i)). It is clear that poles NS and NR repel each other and so do the poles SS and SR. Therefore, the rotor tends to move in the anticlockwise direction. After a period of half-cycle (or ? = 1 /100 second), the polarities of the stator poles are reversed but the polarities of the rotor poles remain the same as shown in Fig. (11. 2 (ii)). Now SS and NR attract 294 each other and so do NS and SR. Therefore, the rotor tends to move in the clockwise direction. Since the stator poles change their polarities rapidly, they tend to pull the rotor first in one direction and then after a period of half-cycle in the other. Due to high inertia of the rotor, the motor fails to start. Fig. (10. 2) Hence, a synchronous motor has no self-starting torque i. e. , a synchronous motor cannot start by itself.How to get continuous unidirectional torque? If the rotor poles are rotated by some external means at such a speed that they interchange their positions along with the stator poles, then the rotor will experience a continuous unidirectional torque. This can be understood from the following discussion: (i) Suppose the stator field is rotating in the clockwise direction and the rotor is als o rotated clockwise by some external means at such a speed that the rotor poles interchange their positions along with the stator poles. (ii) Suppose at any instant the stator and rotor poles are in the position shown in Fig. 11. 3 (i)). It is clear that torque on the rotor will be clockwise. After a period of half-cycle, the stator poles reverse their polarities and at the same time rotor poles also interchange their positions as shown in Fig. (11. 3 (ii)). The result is that again the torque on the rotor is clockwise. Hence a continuous unidirectional torque acts on the rotor and moves it in the clockwise direction. Under this condition, poles on the rotor always face poles of opposite polarity on the stator and a strong magnetic attraction is set up between them.This mutual attraction locks the rotor and stator together and the rotor is virtually pulled into step with the speed of revolving flux (i. e. , synchronous speed). (iii) If now the external prime mover driving the rotor is removed, the rotor will continue to rotate at synchronous speed in the clockwise direction because the rotor poles are magnetically locked up with the stator poles. It is due to 295 this magnetic interlocking between stator and rotor poles that a synchronous motor runs at the speed of revolving flux i. e. , synchronous speed. Fig. (11. 3) 11. Making Synchronous Motor Self-Starting A synchronous motor cannot start by itself. In order to make the motor self-starting, a squirrel cage winding (also called damper winding) is provided on the rotor. The damper winding consists of copper bars embedded in the pole faces of the salient poles of the rotor as shown in Fig. (11. 4). The bars are short-circuited at the ends to form in effect a partial Fig. (11. 4) squirrel cage winding. The damper winding serves to start the motor. (i) To start with, 3-phase supply is given to the stator winding while the rotor field winding is left unenergized.The rotating stator field induces currents in the damper or squirrel cage winding and the motor starts as an induction motor. (ii) As the motor approaches the synchronous speed, the rotor is excited with direct current. Now the resulting poles on the rotor face poles of opposite polarity on the stator and a strong magnetic attraction is set up between them. The rotor poles lock in with the poles of rotating flux. Consequently, the rotor revolves at the same speed as the stator field i. e. , at synchronous speed. iii) Because the bars of squirrel cage portion of the rotor now rotate at the same speed as the rotating stator field, these bars do not cut any flux and, therefore, have no induced currents in them. Hence squirrel cage portion of the rotor is, in effect, removed from the operation of the motor. 296 It may be emphasized here that due to magnetic interlocking between the stator and rotor poles, a synchronous motor can only run at synchronous speed. At any other speed, this magnetic interlocking (i. e. , rotor poles facing o pposite polarity stator poles) ceases and the average torque becomes zero.Consequently, the motor comes to a halt with a severe disturbance on the line. Note: It is important to excite the rotor with direct current at the right moment. For example, if the d. c. excitation is applied when N-pole of the stator faces Npole of the rotor, the resulting magnetic repulsion will produce a violent mechanical shock. The motor will immediately slow down and the circuit breakers will trip. In practice, starters for synchronous motors arc designed to detect the precise moment when excitation should be applied. 11. 5 Equivalent Circuit Unlike the induction motor, the synchronous motor is connected to two electrical systems; a d. . source at the rotor terminals and an a. c. system at the stator terminals. 1. Under normal conditions of synchronous motor operation, no voltage is induced in the rotor by the stator field because the rotor winding is rotating at the same speed as the stator field. Only the impressed direct current is present in the rotor winding and ohmic resistance of this winding is the only opposition to it as shown in Fig. (11. 5 (i)). 2. In the stator winding, two effects are to be considered, the effect of stator field on the stator winding and the effect of the rotor field cutting the stator conductors at synchronous speed.Fig. (11. 5) (i) The effect of stator field on the stator (or armature) conductors is accounted for by including an inductive reactance in the armature winding. This is called synchronous reactance Xs. A resistance Ra must be considered to be in series with this reactance to account for the copper losses in the stator or armature winding as shown in Fig. (11. 5 (i)). This 297 resistance combines with synchronous reactance and gives the synchronous impedance of the machine. (ii) The second effect is that a voltage is generated in the stator winding by the synchronously-revolving field of the rotor as shown in Fig. 11. 5 (i)). This generat ed e. m. f. EB is known as back e. m. f. and opposes the stator voltage V. The magnitude of Eb depends upon rotor speed and rotor flux ? per pole. Since rotor speed is constant; the value of Eb depends upon the rotor flux per pole i. e. exciting rotor current If. Fig. (11. 5 (i)) shows the schematic diagram for one phase of a star-connected synchronous motor while Fig. (11. 5 (ii)) shows its equivalent circuit. Referring to the equivalent circuit in Fig. (11. 5 (ii)). Net voltage/phase in stator winding is Er = V ? Eb Armature current/phase, I a = where 2 Zs = R 2 + X s a hasor difference Er Zs This equivalent circuit helps considerably in understanding the operation of a synchronous motor. A synchronous motor is said to be normally excited if the field excitation is such that Eb = V. If the field excitation is such that Eb < V, the motor is said to be under-excited. The motor is said to be over-excited if the field excitation is such that Eb > V. As we shall see, for both normal an d under excitation, the motor has lagging power factor. However, for over-excitation, the motor has leading power factor.Note: In a synchronous motor, the value of Xs is 10 to 100 times greater than Ra. Consequently, we can neglect Ra unless we are interested in efficiency or heating effects. 11. 6 Motor on Load In d. c. motors and induction motors, an addition of load causes the motor speed to decrease. The decrease in speed reduces the counter e. m. f. enough so that additional current is drawn from the source to carry the increased load at a reduced speed. This action cannot take place in a synchronous motor because it runs at a constant speed (i. e. , synchronous speed) at all loads.What happens when we apply mechanical load to a synchronous motor? The rotor poles fall slightly behind the stator poles while continuing to run at 298 synchronous speed. The angular displacement between stator and rotor poles (called torque angle ? ) causes the phase of back e. m. f. Eb to change w. r. t. supply voltage V. This increases the net e. m. f. Er in the stator winding. Consequently, stator current Ia ( = Er/Zs) increases to carry the load. Fig. (11. 6) The following points may be noted in synchronous motor operation: (i) A synchronous motor runs at synchronous speed at all loads.It meets the increased load not by a decrease in speed but by the relative shift between stator and rotor poles i. e. , by the adjustment of torque angle ?. (ii) If the load on the motor increases, the torque angle a also increases (i. e. , rotor poles lag behind the stator poles by a greater angle) but the motor continues to run at synchronous speed. The increase in torque angle ? causes a greater phase shift of back e. m. f. Eb w. r. t. supply voltage V. This increases the net voltage Er in the stator winding. Consequently, armature current Ia (= Er/Zs) increases to meet the load demand. iii) If the load on the motor decreases, the torque angle ? also decreases. This causes a smaller phase shift of Eb w. r. t. V. Consequently, the net voltage Er in the stator winding decreases and so does the armature current Ia (= Er/Zs). 11. 7 Pull-Out Torque There is a limit to the mechanical load that can be applied to a synchronous motor. As the load increases, the torque angle ? also increases so that a stage is reached when the rotor is pulled out of synchronism and the motor comes to a standstill. This load torque at which the motor pulls out of synchronism is called pull—out or breakdown torque.Its value varies from 1. 5 to 3. 5 times the full— load torque. When a synchronous motor pulls out of synchronism, there is a major disturbance on the line and the circuit breakers immediately trip. This protects the motor because both squirrel cage and stator winding heat up rapidly when the machine ceases to run at synchronous speed. 299 11. 8 Motor Phasor Diagram Consider an under-excited ^tar-connected synchronous motor (Eb < V) supplied with fixed excitation i. e. , back e. m. f. Eb is constantLet V = supply voltage/phase Eb = back e. m. f. /phase Zs = synchronous impedance/phase (i) Motor on no loadWhen the motor is on no load, the torque angle ? is small as shown in Fig. (11. 7 (i)). Consequently, back e. m. f. Eb lags behind the supply voltage V by a small angle ? as shown in the phasor diagram in Fig. (11. 7 (iii)). The net voltage/phase in the stator winding, is Er. Armature current/phase, Ia = Er/Zs The armature current Ia lags behind Er by ? = tan-1 Xs/Ra. Since Xs >> Ra, Ia lags Er by nearly 90Â °. The phase angle between V and Ia is ? so that motor power factor is cos ?. Input power/phase = V Ia cos ? Fig. (11. 7) Thus at no load, the motor takes a small power VIa cos ? phase from the supply to meet the no-load losses while it continues to run at synchronous speed. (ii) Motor on load When load is applied to the motor, the torque angle a increases as shown in Fig. (11. 8 (i)). This causes Eb (its magnitude is constant as excitation is fixed) to lag behind V by a greater angle as shown in the phasor diagram in Fig. (11. 8 (ii)). The net voltage/phase Er in the stator winding increases. Consequently, the motor draws more armature current Ia (=Er/Zs) to meet the applied load. Again Ia lags Er by about 90Â ° since Xs >> Ra. The power factor of the motor is cos ?. 300 Input power/phase, Pi = V Ia cos ?Mechanical power developed by motor/phase Pm = Eb ? Ia ? cosine of angle between Eb and Ia = Eb Ia cos(? ? ? ) Fig. (11. 8) 11. 9 Effect of Changing Field Excitation at Constant Load In a d. c. motor, the armature current Ia is determined by dividing the difference between V and Eb by the armature resistance Ra. Similarly, in a synchronous motor, the stator current (Ia) is determined by dividing voltage-phasor resultant (Er) between V and Eb by the synchronous impedance Zs. One of the most important features of a synchronous motor is that by changing the field excitation, it can be made to operate from lagging to eadin g power factor. Consider a synchronous motor having a fixed supply voltage and driving a constant mechanical load. Since the mechanical load as well as the speed is constant, the power input to the motor (=3 VIa cos ? ) is also constant. This means that the in-phase component Ia cos ? drawn from the supply will remain constant. If the field excitation is changed, back e. m. f Eb also changes. This results in the change of phase position of Ia w. r. t. V and hence the power factor cos ? of the motor changes. Fig. (11. 9) shows the phasor diagram of the synchronous motor for different values of field excitation.Note that extremities of current phasor Ia lie on the straight line AB. (i) Under excitation The motor is said to be under-excited if the field excitation is such that Eb < V. Under such conditions, the current Ia lags behind V so that motor power factor is lagging as shown in Fig. (11. 9 (i)). This can be easily explained. Since Eb < V, the net voltage Er is decreased and turn s clockwise. As angle ? (= 90Â °) between Er and Ia is constant, therefore, phasor Ia also turns clockwise i. e. , current Ia lags behind the supply voltage. Consequently, the motor has a lagging power factor. 301 ii) Normal excitation The motor is said to be normally excited if the field excitation is such that Eb = V. This is shown in Fig. (11. 9 (ii)). Note that the effect of increasing excitation (i. e. , increasing Eb) is to turn the phasor Er and hence Ia in the anti-clockwise direction i. e. , Ia phasor has come closer to phasor V. Therefore, p. f. increases though still lagging. Since input power (=3 V Ia cos ? ) is unchanged, the stator current Ia must decrease with increase in p. f. Fig. (11. 9) Suppose the field excitation is increased until the current Ia is in phase with the applied voltage V, making the p. . of the synchronous motor unity [See Fig. (11. 9 (iii))]. For a given load, at unity p. f. the resultant Er and, therefore, Ia are minimum. (iii) Over excitation T he motor is said to be overexcited if the field excitation is such that Eb > V. Under-such conditions, current Ia leads V and the motor power factor is leading as shown in Fig. (11. 9 (iv)). Note that Er and hence Ia further turn anti-clockwise from the normal excitation position. Consequently, Ia leads V. From the above discussion, it is concluded that if the synchronous motor is under-excited, it has a lagging power factor.As the excitation is increased, the power factor improves till it becomes unity at normal excitation. Under such conditions, the current drawn from the supply is minimum. If the excitation is further increased (i. e. , over excitation), the motor power factor becomes leading. Note. The armature current (Ia) is minimum at unity p. f and increases as the power factor becomes poor, either leading or lagging. 302 11. 10 Phasor Diagrams With Different Excitations Fig. (11. 10) shows the phasor diagrams for different field excitations at constant load. Fig. (11. 10 (i )) shows the phasor diagram for normal excitation (Eb = V), whereas Fig. 11. 10 (ii)) shows the phasor diagram for under-excitation. In both cases, the motor has lagging power factor. Fig. (11. 10 (iii)) shows the phasor diagram when field excitation is adjusted for unity p. f. operation. Under this condition, the resultant voltage Er and, therefore, the stator current Ia are minimum. When the motor is overexcited, it has leading power factor as shown in Fig. (11. 10 (iv)). The following points may be remembered: (i) For a given load, the power factor is governed by the field excitation; a weak field produces the lagging armature current and a strong field produces a leading armature current. ii) The armature current (Ia) is minimum at unity p. f and increases as the p. f. becomes less either leading or lagging. Fig. (11. 10) 11. 11 Power Relations Consider an under-excited star-connected synchronous motor driving a mechanical load. Fig. (11. 11 (i)) shows the equivalent circuit for one phase, while Fig. (11. 11 (ii)) shows the phasor diagram. Fig. (11. 11) 303 (i) (ii) Input power/phase, Pi = V Ia cos ? Mechanical power developed by the motor/phase, Pm = Eb ? Ia ? cosine of angle between Eb and Ia = Eb Ia cos(? ? ? ) Armature Cu loss/phase = I 2 R a = Pi ? Pm a Output power/phasor, Pout = Pm ?Iron, friction and excitation loss. (iii) (iv) Fig. (11. 12) shows the power flow diagram of the synchronous motor. Fig. (11. 12) 11. 12 Motor Torque Gross torque, Tg = 9. 55 where Pm N-m Ns Pm = Gross motor output in watts = Eb Ia cos(? ? ? ) Ns = Synchronous speed in r. p. m. Shaft torque, Tsh = 9. 55 Pout N-m Ns It may be seen that torque is directly proportional to the mechanical power because rotor speed (i. e. , Ns) is fixed. 11. 13 Mechanical Power Developed By Motor (Armature resistance neglected) Fig. (11. 13) shows the phasor diagram of an under-excited synchronous motor driving a mechanical load.Since armature resistance Ra is assumed zero. tan? = Xs/Ra = ? an d hence ? = 90Â °. Input power/phase = V Ia cos ? Fig. (11. 13) 304 Since Ra is assumed zero, stator Cu loss (I 2 R a ) will be zero. Hence input power a is equal to the mechanical power Pm developed by the motor. Mech. power developed/ phase, Pm = V Ia cos ? Referring to the phasor diagram in Fig. (11. 13), (i) AB = E r cos ? = I a X s cos ? Also AB = E b sin ? ? E b sin ? = I a X s cos ? or I a cos ? = E b sin ? Xs Substituting the value of Ia cos ? in exp. (i) above, Pm = = V Eb Xs VEb Xs per phase for 3-phaseIt is clear from the above relation that mechanical power increases with torque angle (in electrical degrees) and its maximum value is reached when ? = 90Â ° (electrical). Pmax = V Eb Xs per phase Under this condition, the poles of the rotor will be mid-way between N and S poles of the stator. 11. 14 Power Factor of Synchronous Motors In an induction motor, only one winding (i. e. , stator winding) produces the necessary flux in the machine. The stator winding must draw re active power from the supply to set up the flux. Consequently, induction motor must operate at lagging power factor.But in a synchronous motor, there are two possible sources of excitation; alternating current in the stator or direct current in the rotor. The required flux may be produced either by stator or rotor or both. (i) If the rotor exciting current is of such magnitude that it produces all the required flux, then no magnetizing current or reactive power is needed in the stator. As a result, the motor will operate at unity power factor. 305 (ii) If the rotor exciting current is less (i. e. , motor is under-excited), the deficit in flux is made up by the stator. Consequently, the motor draws reactive power to provide for the remaining flux.Hence motor will operate at a lagging power factor. (iii) If the rotor exciting current is greater (i. e. , motor is over-excited), the excess flux must be counterbalanced in the stator. Now the stator, instead of absorbing reactive power, a ctually delivers reactive power to the 3-phase line. The motor then behaves like a source of reactive power, as if it were a capacitor. In other words, the motor operates at a leading power factor. To sum up, a synchronous motor absorbs reactive power when it is underexcited and delivers reactive power to source when it is over-excited. 11. 15 Synchronous CondenserA synchronous motor takes a leading current when over-excited and, therefore, behaves as a capacitor. An over-excited synchronous motor running on no-load in known as synchronous condenser. When such a machine is connected in parallel with induction motors or other devices that operate at low lagging power factor, the leading kVAR supplied by the synchronous condenser partly neutralizes the lagging reactive kVAR of the loads. Consequently, the power factor of the system is improved. Fig. (11. 14) shows the power factor improvement by synchronous condenser method. The 3 ? ? load takes current IL at low lagging power factor cos ?L. The synchronous condenser takes a current Im which leads the voltage by an angle ? m. The resultant current I is the vector sum of Im and IL and lags behind the voltage by an angle ?. It is clear that ? is less than ? L so that cos ? is greater than cos ? L. Thus the power factor is increased from cos ? L to cos ?. Synchronous condensers are generally used at major bulk supply substations for power factor improvement. Advantages (i) By varying the field excitation, the magnitude of current drawn by the motor can be changed by any amount. This helps in achieving stepless control of power factor. ii) The motor windings have high thermal stability to short circuit currents. (iii) The faults can be removed easily. 306 Fig. (11. 14) Disadvantages (i) (ii) (iii) (iv) There are considerable losses in the motor. The maintenance cost is high. It produces noise. Except in sizes above 500 RVA, the cost is greater than that of static capacitors of the same rating. (v) As a synchronous m otor has no self-starting torque, then-fore, an auxiliary equipment has to be provided for this purpose. 11. 16 Applications of Synchronous Motors (i) Synchronous motors are particularly attractive for low speeds (< 300 r. . m. ) because the power factor can always be adjusted to unity and efficiency is high. (ii) Overexcited synchronous motors can be used to improve the power factor of a plant while carrying their rated loads. (iii) They are used to improve the voltage regulation of transmission lines. (iv) High-power electronic converters generating very low frequencies enable us to run synchronous motors at ultra-low speeds. Thus huge motors in the 10 MW range drive crushers, rotary kilns and variable-speed ball mills. 307 11. 17 Comparison of Synchronous and Induction Motors S. Particular No. 1.Speed 2. 3. 4. Power factor Excitation Economy 3-phase Induction Motor Remains constant (i. e. , Ns) from Decreases with load. no-load to full-load. Can be made to operate from Operates a t lagging lagging to leading power factor. power factor. Requires d. c. excitation at the No excitation for the rotor. rotor. Economical fcr speeds below Economical for 300 r. p. m. speeds above 600 r. p. m. Self-starting No self-starting torque. Auxiliary means have to be provided for starting. Complicated Simple More less Synchronous Motor 5. Self-starting 6. 7. Construction Starting torque 308

Eyewitness Auschwitz

During the attempted extermination of the entire Jewish population, many Jewish prisoners were ordered to assist in the killing of their own people. Sonderkommandos were a major part of this eradication. A sonderkommando aided in the disposal of the corpses that were victims to the gas chambers. Through the vivid testimony by Filip Muller, â€Å"Eyewitness Auschwitz† allows the reader to fully understand the difficulties and graphic situations that occurred daily at Auschwitz. Filip Muller was born on January 3, 1922 in Sered, Czechoslovakia.In 1942 at the age of 20, he was deported to the death camp. He was one of the few Sonderkommandos to have survived Auschwitz. The memoir greatly details the resilience of the human spirit, the choices individuals were faced with and decided to act upon and, the treatment of those who had succumbed. The personal choices that some made were extremely unmoral. â€Å"†Every day we saw thousands and thousands of innocent people disappea r up the chimney. With our own eyes, we could truly fathom what it means to be a human being.There they came, men, women, children, all innocent. They suddenly vanished, and the world said nothing .. † An example of an unmoral prisoner was the Kapo Mietek, who was trusted to discipline the working prisoners. According to Muller, it was not necessary for Mietek to treat his fellow prisoners as human beings but rather beat them mercilessly to gain appreciation from the Nazi leaders. Another theme that Muller presents in his testimony is dehumanization of the camp’s victims.Approximately seventy percent of the prisoners that arrived at Auschwitz were immediately gassed. Their hair was shaven and their bodies were exploited in order to find valuables for the Nazi’s economic gain. A memoir is by definition â€Å"a  record  of  events  written  by  a  person  having  intimate knowledge  of  them  and  based  on  personal  observationâ⠂¬ . While Filip Muller’s testimony could be extremely accurate, it could also be extremely flawed. As a prisoner at a death camp-watching people die daily, it can weigh heavily on one’s conscious.This in turn can alter one’s memory and/or create an entire new memory that never happened. The validity of Muller’s memoir could all be a figment of his imagination due to the emotional and physical stress and agony of being a prisoner although I highly doubt that the validity is compromised. â€Å"Eyewitness Auschwitz† is a key document of the Holocaust. It is published with an association of the United States Holocaust Memorial Museum, which is highly renown. â€Å"Eyewitness Auschwitz† is a personal testimony of the hell that resided within the death camps.Filip Muller does an excellent job of describing the daily activities of a Sonderkommando, which few lived to tell about. At times it is extremely difficult to read due to the graphic nature of the text. Muller discusses themes that the entire camp system was set on such as dehumanization and the immorality of the soldiers as well as fellow prisoners. Filip Muller wrote a very powerful book that reaches deep within the reader and wrenches on their emotions.

Plato's Academy Essay Example | Topics and Well Written Essays - 1000 words

Plato's Academy - Essay Example Although Plato did deliver his lectures there, "the metaphysical theories of the director [Plato] were not in any way 'official' and the formal instruction in the Academy was restricted to mathematics" (Chermiss 1980, p.18). In other words, the Academy was an association of highly educated people engaged in independent research and studies. As the founding father of the Academy, Plato became its first Head (scholarch) and remained at this position for forty years. Plato's immediate successor as the Head of the Academy was his 40-year old nephew Speusippus (347-339 BC) who, after his uncle's death in 347BC, remained scholarch for the next eight years. According to his contemporaries, Speusippus was a proliferate writer who produced many works written in the form of treatise and dialogues. Unfortunately, we have only few of the texts attributed to him: the information on Speusippus ideas and doctrines is primarily retrieved from third party sources (Dilon 2003). The scarce information available these days makes it clear that despite his familial connection with Plato, Speusippus could barely be named as the continuator of his uncle's major ideas. In particular, Speusippus rejected the famous Theory of Forms developed by Plato during his years at the Academy. Besides, Speusippus believed that the Good was secondary while Plato maintained the Good was ultimately primary. Also, Speusippus claimed it was not possible to have comprehensive knowledge of any thing without understanding of the properties that distinguish this thing from other things. These views differed substantially from the principles argued by Plato in his broad philosophic doctrine. And only in his works dedicated to ethics, Speusippus abided by the views similar to those of Plato: he further elaborated Plato's ideas of citizenship, justice and legislation as well as opposed the hedonistic theory of the value of life proposed by Aristippus of Cyrene, founder of the Cyrenaic sc hool. Speusippus also studied the science of numbers and, contrary to Plato, rejected the theory of ideal numbers (the Platonic Forms of numbers) which further led him to rejection of the Platonic concept of ideas in general (Smith 2007, III, pp. 893-894). In 339BC, Xenocrates of Chalcedon, a renowned philosopher and mathematician, became the next scholarch of the Academy. Xenocrates did abide by the views of Plato and further elaborated the ideas and theories of his famous predecessor often using mathematical instruments and elements in doing so. In particular, Xenocrates contributed significantly to the studies of demonology (Platonic theology). The scholar believed that duality and unity were gods which ruled the world and pervaded all things while the human soul was a self-moving number and that the demonical powers that also existed in the universe acted as an intermediate link or channel between the divine and the soul: "Xenocrates distinguishes three cosmological causes: the Forms as original patterns, the demiurge, and matter. Via allegories he combines the philosophical worldview with mythical religion" (Ricken 1991 pp. 119-120). Xenocrates' interpretations of Plato's principles (particularly his attempt to order philosophic p rinciples into logic and mathematics) seriously supplemented the foundations of Platonist philosophy. Polemon of Athens became the Head of the Academy in 314

Society & Bullshit Essay Example | Topics and Well Written Essays - 500 words

Society & Bullshit - Essay Example As bullshit does not reject the authority of truth, it has a power to pose as truth thus captivating the society. In this manner, it is a bigger enemy of the society than lie (Noah, 2005). A democratic and civilized society being aware of its basic right of truth and justice expects its country’s political disclosure to be based on them. It is important for the political discourse of the country to rely on truth so that the citizens are correctly aware of every situation concerned with their country. Lying, misrepresenting and bullshitting the nation will not only misguide it but would also hinder the society’s growth (McCormack, 2005). In the recent years, the U.S political discourse has become all about misrepresentation, falsifying the truth and lying. The dealings of recent governments depict that there is no place for truth in today’s political culture. President Bush era is a real and proven example of government lies and misrepresentation to the public. His lies and deceits have increased public mistrust in the government. It looks as if today’s political discourse is least concerned with truth seeking and providing it to the public (Arendt, 2009). One of the most famous examples of bullshit in the recent history of U.S political discourse is of President Bush State of the Union address in 2003. Financial Times reported this that the famous war justifying 16 words in the President’s address ("The British government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa")  (Noah, 2005) were bullshit. Use of word â€Å"learned† rather than â€Å"concluded† signifies these words as bullshit. Although these words might be true, but they were bullshit as at the time of making this statement the president and his staff did not have evidence to support their claim, so they were bullshitting (Noah, 2005). These 16

Logistics and Supply Chain Management Consultancy ( team project Essay

Logistics and Supply Chain Management Consultancy ( team project individual reflection) - Essay Example 4). Each of its parts; from description to the action plan is carefully designed to cover virtually every element of a project reflection. Each and every step of the Gibb’s cycle will be closely followed with respect to the details of the teamwork during the project. Per say this consultancy project was not only vital for my personal growth, but also for my programme; I learnt a plethora of lessons, and the experience was nothing short of exhilarating. The project concerned the Port of Dover, a logistics sector owned, maintained and operated by the Dover Harbour Board. This port ranks among the busiest ports in Europe and handles approximately five million excess of vehicles each year. In context, my team comprised of eight members with a single leader (Willeke). Our project, as in the title above, was logistics and supply chain management consultancy. Each day, the team converged in the University Library, or sometimes in the Information Technology Lab. Procedurally, we began by each member of the group tabling their individual report works mostly during the morning hours. Then, a discussion of the progress for each member of the team ensued. Here, each member would present their hardships and everything appertaining to their progress with resp ect to the task allocated. After the discussion, Willeke, the team leader, would give her opinions regarding the overall progress and give her suggestions as well. Concerning task division, the leader began by giving out questionnaires to every member of the team to complete. This step solely applied the Belbin theory of team roles, which in some way, was meant to harmonise the working of the group (Belbin, 2009 p. 3). After that, Microsoft Excel sheets were given to every one of us that would be used for the period of two and a half weeks. Notably yet, all the tasks that would be allocated to the team were based on the two provided files. As one of the members of the team, my primary task was to

Compare and Contrast the 1991 and 2003 Iraq War Case Study

Compare and Contrast the 1991 and 2003 Iraq War - Case Study Example In addition was the allegation that Kuwait was stealing Iraqi oil from the Rumaila oil field by using slant drilling technology. Lastly, Kuwait had refused to allow Iraq access to the Persian Gulf. As a result, in May 1990, the world saw Saddam Hussein openly attacking the Kuwait economic warfare in the Arab League meeting. As Hinnebusch (2007) points out, even after the Iraq threat of military action if Kuwait failed to control over-production, the tiny nation remained firm on its decisions; and the support, undoubtedly came from the US. This fact is evident from the understanding that the US military was preparing for a war against Iraq. For example, in 1989 itself, America had revamped its military doctrine in the Middle East. To illustrate, General Normal Schwarzkopf had already started war games in which US troops fought the Iraqi troops even before the Iraqi aggression on Kuwait. In addition is the fact that the US could not produce any proof to support their claims of Iraqi tr oop deployment against Kuwait. This is especially important considering the fact that Russia produced such satellite imageries that show no important troop deployment from the part of Iraq that threatened Kuwait. Here, one has to again remember that there was no movement from the President to promote diplomacy and negotiations. Evidently, the US wanted to reduce the power and influence of Iraq in the oil rich region of Middle East. So, for the US, a war was necessary. This becomes very evident from the American aggression on Iraq a second time, and this time, on an even weaker and unbelievable basis. The allegation was that Iraq had a role in the 9/11 attack. Though the US could not come up with a believable story up to this time, the idea was supported by the hardliners in the nation. As Kitfield (n.d.) states, another allegation was that there were WMDs but even after the war, no such evidences were brought to the world. In total, one can say that the aggression of Iraq on Kuwait was not a matter of more concern to America than to United Nations. According to Kitfield (n.d), if it took special interest in the matter, it had its own interests to be protected. In order to gain international support, America went on asserting that Iraq was violating Resolution 1441 of 2002 that mandated Iraq to fully declare and eliminate its WMD programs. Also, America got the opinion of other nations including France, Germany, Russia, and China that Iraq was not properly following the guidelines. However, they were not in agreement with the American interest in an immediate attack as they thought the UN efforts should be given more time. Admittedly, the United Nations exhibited its inability and vulnerability to the world in the Iraq wars. For example, the Council used its Chapter VII powers to allow the coalition under the US to take military actions. Soon, there was Operation Desert Shield and Storm, but there arose the issue that the military action was not authorized. For the purpose, Security Council Resolution 687 was passed on 29 November 1990. Here, the council, instead of showing any clearly defined responsibility, made the vague statement that the Security Council be regularly informed. According to Resolution 687, all weapons of mass destruction had to be removed. So, the sanctions for military action under the resolution would remain in force until this end

A Presentation by Raj Rupani - International Tax Manager Essay

A Presentation by Raj Rupani - International Tax Manager - Essay Example In addition, Raj seemed to be quite conversant with the social media; he made us understand the best ways of using the social media both as individuals and in the corporate. There was so much to learn from Raj’s career and training. He mentioned to us about his journey, on how he came to develop a strong passion for accounting. This prompted him to join an accounting school where he successfully finished before joining the work environment. Raj is an accomplished professional who challenged me to have a passion and pursue it fully. What made his presentation even more interesting was the versatility applied. He gave us many experiences from several of his friends and people he had read about, he was quite knowledgeable. At Deloitte, Raj mentions that the career has turned him into a global trotter; he has visited several countries in the world and the chances of touring many more still remain ripe. I really admired his career. Technology is the driver of life in the 21st Century; this was his message concerning the use of technology. He started by dispelling the notion among young people that Facebook and other social media platforms are only used for communicating with friends. His dimension of thought challenged me, he told us how they have capitalized on the social media at Deloitte and have completely transformed the customer experience. Social media makes it easy and convenient to communicate to clients and it is possible to customize the communication to a particular client or a group of clients. Since accounting information in an organization is kept confidential, he mentioned the various ways in which we can be able to have secure social media communication. He took time to motivate us to become our best in whatever we do. Raj’s works still keep on lingering in my mind; he said that we should be able to understand what we are good at and start exercising. Citing his own example, he said an individual who endeavours to pursue accounting should have a passion and a positive attitude towards mathematics and other affiliate courses.  

Human Resource- Succession Planning & Strategic International HRM Essay

Human Resource- Succession Planning & Strategic International HRM - Essay Example Soft competencies, is what the organization needs to focus on. Because of the highly volatile business environment, skill needs change rapidly, making it imperative to focus on soft competencies. Employees should be evaluated based on their capabilities to solve complex issues. The company should focus on long-term succession planning so that any emergency replacements are automatically taken care of. Competencies are groups of related behaviors essential for successful performance. Because of the global operations, the organization needs managers competent with general mobility skills and knowledge. This would ensure managers are effective in group processes, possess the necessary communication skills and are ready to adapt to the changing business needs and environment. Other general competencies that would facilitate success in the global economy include the ability to build a cohesive team and the competency to encourage and motivate employees to accept change. This requires developing a talent management culture within the organization so that talent when recognized should immediately be tapped, trained and developed. Talent management should best be left to the HR personnel as they are professionals and are aware of the benefits and pitfalls of succession planning. They are better positioned to identify gaps between current competencies and those that may be required in the future. To identify talent gaps, more sophisticated rating system should be used. Once high-potential employees have been identified they should be provided with developmental opportunities and experiences. This is strategic replacement strategy where formal identification follows training of successors. In addition, comprehensive job profiles for managerial position would attract the right candidates. The organization should also focus on rewarding loyal and hardworking individuals as this serves to enhance

The Evolution of Multi-National Enterprises Responses to The Research Paper

The Evolution of Multi-National Enterprises Responses to The Challenges of Globalization - Research Paper Example The heterogeneity of the work involved also has become more complex just as in the case of coordination of multiple salary currencies. More research and involvement on the differential operative needs of the company including their staffing policy is also much challenging. However, the process of globalization is, in turn, a matter of scope for companies as it would enable them with the choice of a wide selection of manpower and a diverse market scope spread across the globe. This process has also equipped the management with better connectivity with its counterparts across the globe which is within itself a quality assurance process. Globalization has provided the personnel managers with sufficient choices of capacity building processes for their staff. Diversity within the team enables the management of a wider thought process with differential insights on varied market requirements. So as to formulate the strategic policies pertaining to globalization, it’s important to analyze the range of diversity caused due to globalization. This section of the essay critically analyses the various challenges that the Multi-National Enterprises may face in the context of globalization. With reference to each of these concerns possible responsible by the leaders and the companies also has been explained. A modern definition of culture is â€Å"the shared ways in which groups of people understand and interpret the world (Fons & Charles 1997,p.3-4). A diversity in the interpretation and understanding as defined by Fons & Charles is very possible to be experienced within any team of modern days mainly due to the resultants of globalization namely in- sourcing and outsourcing. Moreover, the policies on the exchange of manpower among different nationalities promoted by the shortage of skilled manpower in many countries have led many working  groups to hire people belonging to different countries with diverse cultures.

NEC Assignment Example | Topics and Well Written Essays - 500 words

NEC - Assignment Example hnology and specialization advanced rapidly, it became more difficult for companies to harness all necessary technologies through their own R&D activities. Consequently they were forming strategic alliances with other firms, laboratories and universities that held competitive edge technologically (Mark 1987). There were several proposed sites for NEC including Boston, Palo Alto and Princeton. Shinoda and Kahng believed it was necessary to establish the laboratory at a relatively quiet place and thus it was conducive to establish the site in Princeton. The closeness of Princeton to Europe was significant for constant communication to the headquarters in Europe. It was essential for NEC to move out of Europe in order to diversify its market and exploit new markets in the globe. Princeton was a strategic position for the development of the company owing to the accessibility of resources. The region having other scientific institutions such as the Bell Laboratories, the IBM Research Institute, and the SRI Institute would facilitate NES with new knowledge that would be essential in establishing of a successful achievement of set objectives. Princeton would also be a convenient place to do collaborative research; this is because of the easy access to universities such as the Princeton University, Columbia University and Yale University. These Universities would greatly help in carrying out research for the firm. I think locating the industry in a region that has other firms already established would be essential for ease in access by clients because clients are already aware of the company’s location. The competition by other similar firm would greatly assist the firm to borrow and make reasonable improvements. Many companies tend to focus on both research and development activities all together; this is not the case with NEC. NEC prefers to entirely focus on research activities alone in the international research center; this decision is accompanied with a number

Dreams in of mice and men Essay Example for Free

Dreams in of mice and men Essay Of Mice and Men Dreams Of Mice and Men is set in Salinas, California in the 1930s Great Depression. Life was hard and men could be cruel. Hope might be the only escape from hard reality. This links to the American Dream – represented in George and Lennie’s dream of working hard and getting their own land and farm, and control over their own lives. But it was harder than ever to achieve due to the tough economic conditions of the Depression. After Lennie’s death, it might be possible for George to realise his dream, but the emptiness at the end of the novel shows that financial success is nothing when you are lonely. So the dream is not just something to own, or possess, but also something to share. ‘Compassion and love’, to Steinbeck – as outlined in his Nobel Prize speech are the most important things, as is ‘hope’ – having a dream. Lennie and George have a fairly simple dream: to own a small farm, and be their own bosses, which contrasts with the large factory type farm they are on, where men are treated like machines, which are frequently broken (Crooks and Candy), and isolated from each other. George repeats his and Lennie’s dream like a mantra: ‘we got a future’, suggesting that they are different to the others. ‘Future’ here is a metaphor for something bright, and greater than what they have now – like the American Dream to ‘live off the fatta the land’. The phrase ‘fat of the land’ almost suggests a biblical promised land after the hard, ‘wilderness’ years. The function of the dream therefore is to help them to endure hardship and not give in to despair. They want control of their own lives: ‘we’ll just say the hell with goin to work’. This can make them seem naive however, as farmers have to work whether they want to or not – especially smallholders. When George sets out the dream, he then says that he and Lennie are ‘not like those other guys’. The dream sets George and Lennie apart from the others; they make themselves special: in the inclusive ‘we’ against the exclusive ‘those other guys’. The juxtaposition of ‘us’ and ‘them’ verbally bonds the protagonists together in contrast to the other men – even though they are all, George, Lennie, Crooks, Candy, in the same situation. Still, George and Lennie separate themselves from the others by using the third person to describe farm hands as, ‘the loneliest guys in the world.’ The superlative ‘loneliest’ and hyperbole ‘in the world’ exaggerates the harshness of the world of the Depression as shown in the novel. Sometimes it seems that George ‘owns’ the dream – as he is the one who tells it to Lennie, like a child’s bedtime story, prayer or mantra, in keeping with his role as ‘parent/protector’ to his child-like companion. This is emphasised by the simple, mantra-like structure, where Lennie keeps filling in the gaps if George hesitates, and repeating short phrases after him as if he knows it by heart, even though – as George says frustratedly, Lennie always ‘forgets’ everything else. It is not always certain if George believes the dream is possible or if he is saying it to keep Lennie quiet. Sometimes, George seems sceptical, saying they will have ‘every colour rabbits’ including ‘red and blue’. He is patronising to Lennie, saying ‘good boy’, keeping him safe from his own stupidity. In these scenes the dream seems more of a spell or placebo to keep the main characters safe than something that is really possible. Other characters are very cynical about the dream. The reader is made to question how realistic these dreams are. Curley’s wife dreams of when she threw away the chance to become famous, but we can see that her dream is a sham. Of George and Lennie’s dream, Crooks says: ‘every damn one of them’s got a little piece of land in his head’. Crooks’ final judgement is that ‘never a God damn one of ‘em ever gets it.’ The repetition of the absolute ‘never’ and ‘ever’, as well as the strong slang ‘God damn’ emphasises how desperate life is. However, it is not certain whether Steinbeck shares Crooks’ negative view. Crooks is an extreme character. His language is hyperbole – very extreme and relentlessly negative. Crooks’ phrase ‘God damn’ suggests that God has abandoned these men, in contrast to the biblical image of hope in George and Lennie’s dream of living ‘off the fatta the land’. The biblical imagery continues negatively when Crooks compares the dream of land to being ‘like Heaven’ – the Christian idea of perfect bliss, not considered a physical reality – and which Crooks says is just as impossible to get as a piece of land. It’s hard for George to keep Lennie out of trouble and keep them on track for their dream. But when they tell Candy, it starts to seem as if it might be possible. [needs evidence/ quotation/ language analysis] In an instant, Candy’s faith (and money) take them close to the ideal/dream becoming real. As the dream is shared, or heard by more people, the more it seems that together they might make it come true. Even the ultra negative Crooks starts to believe.[needs evidence/ quotation/ language analysis] But all the time, Steinbeck has built up a foreboding feeling, that this world is hard and horrible and nothing good can live in it. We feel that the gentleness of Lennie and George’s friendship, and their shared dream, will be crushed by the cruel world – even by Lennie’s desire for gentle, soft things. ‘I like soft things’ Every time he kills an animal – mouse or puppy, Lennie’s biggest, darkest fear is that he won’t be allowed ‘to tend the rabbits’. The dream is so precious to him that he wants it at any cost. Curley’s wife is lonely and wants someone to listen to her dream. [needs evidence/ quotation/ language analysis] When she finds Lennie in the barn, she lets him stroke her hair. When she starts screaming, Lennie screams at her to stop or ‘George won’t let me tend the rabbits’. She’s so frightened that she can’t stop and Lennie accidentally kills her. In a way, Lennie’s desire to keep the dream (by keeping Curley’s wife quiet – and smothering her) is the thing that has destroyed it. The irony of this makes it even more poignant. When Candy discovers what has happened all he wants to know is that he and George can still get the farm. [needs evidence/ quotation/ language analysis] He loses sight of human decency – the woman is dead and Lennie will soon die too. Steinbeck makes us ask whether any dream of financial prosperity should be more important than human life? Should we try to get it at any cost? At the end, George tells Lennie the ‘fairy story’ of the dream again – to make him happy at the moment he has to kill the dream of togetherness by shooting him in the head. He almost can’t speak because he is so upset. [needs evidence/ quotation/ language analysis] Even though George could still have the farm with Candy, he is deeply sad that he couldn’t keep Lennie alive. Because the dream isn’t worth much when he doesn’t have his old friend to share it with. Lennie loved the dream more than anyone and he never gets it.

Learning Theories and Cognitive Development

Learning Theories and Cognitive Development Vygotsky, Bruner, and Dienes share the cognitive viewpoint of learning. Lev Vygotsky, a constructive theorist, viewed social and cognitive development as working jointly while building on each other. One of Vygotskys major contributions to understanding child development, is the concept of the zone of proximal development (Mooney, 2013). Vygotsky believed this concept to be the difference between what a child can accomplish on his own, and what he can do with the assistance of a teacher or peer. In conjunction with the zone of proximal development, scaffolding is vital to a childs development. In Vygotskys view, scaffolding is instrumental in the childs development of knowledge and skills (Shemmar Al-Thani, 2015). Vygotsky advocated for observation in promoting a childs development. Teachers become familiar with a childs development through listening and watching his behavior, in this way, a greater degree of learning occurs as the teacher is aware of what the student knows, and can relate it to learning new concepts. In Vygotskys view, social interaction promotes individualized thinking. Concerned with the process of learning and instruction, Jerome Bruners theory supports children learning through guidance and support. Similar to Vygotsky, Bruner believed instructional scaffolding to be vital to a childs cognitive development. In Bruners view, any student can be taught any subject regardless of his stage of development, given support is provided in the right way, at the right time (Choudhry, 2013). An advocate for discovery learning, Bruner believed learning to be an active process. Learners create new ideas or concepts based on existing knowledge. Bruners theory of learning was based on children learning through three phases of cognitive development in which he or she progresses: the enactive phase, iconic stage, and the symbolic mode (Choudhry, 2013). Focusing primarily on mathematics, Zoltan Dienes theory of learning includes applying teaching practices that consider childrens learning styles, and the rate their learning occurs (Gningue, 2016). Dienes theory includes the use of manipulative materials, games and stories. He believed at an earlier age than previously thought, children can comprehend complicated math concepts than previously assumed. Per Dienes theory, mastering a new concept is a process that evolves over time, and involves the child progressing through stages, or cycles of learning (Gningue, 2016). Vygotsky, Bruner, and Dienes Versus Piaget The work of Lev Vygotsky and Jean Piaget are often compared because they both acknowledged the participation of individuals in constructing knowledge; however, there are also differences in their schools of thought. Central to Piagets theory, cognitive development follows four universal stages, in which more sophisticated, and abstract thought increases. Piagets theory holds that stages occur in the same order, building on knowledge gained from the previous stage, and grouped according to age in which the childs abilities are classified. Vygotsky took the position that through adult assistance, a child is gradually capable of performing tasks without assistance. Development is a result of the childs interaction with assimilation and accommodation in which a balance between preexisting concepts and new information is attained, and new knowledge is constructed (Choudhry, 2013). Piaget thought that a child is actively involved in his learning, and learning was a result of the childs int eraction with his environment. Vygotsky also considered children as active participants in their learning; however, he focused on the impact of social interaction and language on a childs cognitive development, and believed personal and social experiences cannot be separated (Mooney, 2013). Another similarity of Vygotsky and Piaget, is their view on the importance of play in a childs development and learning. In contrast to Piagets stage theory of a childs development, Bruner believed children could learn any subject with the support and guidance of an adult. Bruner, like Piaget, saw children as actively involved in their learning process. Similar to Piagets stages, Bruners theory also consisted of phases of development in which children progress as they learn and develop. However, Bruners modes were interrelated, unlike Piagets specifically defined stages. Unlike Piaget, Dienes focused primarily on childrens learning and development of mathematical concepts. Dienes theory involves progressive stages to learning math, much like Piagets theory of cognitive development. Piaget proposed that children learn best from concrete activities, similarly Dienes theory also emphasized the importance of children learning through the use of manipulative materials (Gningue, 2016). Additional Theorists John Dewey was instrumental in developing theories regarding young childrens learning and development. In agreement with Piaget and Vygotsky, Dewey saw the child as an active part of his learning process, and learning as child centered, and interactive (Mooney, 2013). Dewey believe the childs social world and community to be vital to his development. Dewey emphasized the role of the teacher in observing students to understand what kind of experiences they were interested in, and plan curriculum to help children understand his or her world. Maria Montessori developed a child centered approach to learning. She believed children learn skills, including language, naturally from his or her environment, and placed emphasis on preparation of the learning environment (Mooney, 2013). Montessoris work suggests that the most critical time of learning is during the first years of life, and learning comes through manipulation of the environment and training of the senses (Platz Arellano, 2011). Montessoris curriculum was based on the philosophy that educators should be passive but provide guidance as children are active participants in their learning process. John Locke saw children as a blank slate in their nature and ability to learn (Platz Arellano, 2011). Childrens nature and learning are influenced by their environment, and their early experiences had a lasting effect on their future. Locke also saw children as individuals who should be raised based on their individuality and taught according to their individual needs (Platz Arellano, 2011). Lockes view supports teaching children to read as soon as they learn to speak. Credited with the development of kindergarten curriculum, Froebel saw the importance of using play as a teaching strategy for young children. Froebels play curriculum did not include instruction on reading, writing, or counting (Platz Arellano, 2011). Play, games, and songs are vital to developing attitudes of cooperation and self-control in children. Froebel believed block play to be essential in child development as it represented the building blocks of the universe (Platz Arellano, 2011). References Choudhry, M. (2013). Constructivism: Way to new learning. International Journal of Education and Management Studies, 3(2), 276-284. Gningue, S. M. (2016). Remembering Zoltan Dienes, a Maverick of Mathematics Teaching and Learning: Applying the Variability Principles to Teach Algebra. International Journal for Mathematics Teaching and Learning, 17(2). Retrieved from http://www.cimt.org.uk/ijmtl/index.php/IJMTL/article/view/17 Platz D. and Arellano, J. (2011) Time tested early childhood theories and practices. Education. 32(1), 54-61. Retrieved from https://www.questia.com/read/1G1-269228798/time-tested-early-childhood-theories-and-practices

Mechanism and Optimization of Melphalan

Mechanism and Optimization of Melphalan Melphalan Introduction Cancer in general is referred to body cells that grows rapidly and over the limit of normal cells (Hayflick limit). There’s over 200 different types of cancer, where some cancer cells can spread to other parts of the body leading to further complications. It’s one of the biggest leading cause of death worldwide. Therefore interest in finding treatment and prevention for this disease has been growing. One of the most successful chemotherapy drugs is Melphalan. It’s been over 50 years in use and there’s an increase in research to improve this drug. It’s indicated for different type of cancer: for the analgesic treatment of multiple myeloma (MM) and for the alleviation of unresectable epithelial tumor of the ovary. It has also been used alone or in combination with other chemotherapy drugs for relief treatment of locally repeated or unresectable in-transit metastatic melanoma of the extremities. It’s also used in addition to other drugs or surge ry in breast cancer. Mechanism of action Melphalan belong to a class of chemotherapy drugs called nitrogen mustardalkylating agents. It’s the oldest class of anticancer drugs still frequently used. It’s a bifunctional alkylating agent which means it has two sites where the reactivity occurs. It displaces the chloride ion by amine nitrogen to form a cyclic amine ion (aziridinium ring) by intramolecular nucleophilic attack. Afterwards the DNA nucleophile undergoes a nucleophilic attack and opens the azidrine ring, which leads to the alkylation of DNA. The lone pair of electrons on the nitrogen in the drug will then be regenerated when the azidine ring cleaves. The same reactions happen on the second reactive site of the drug, by displacing the second chloride ion. (picture) This will lead to cross-linked DNA molecules through covalent bonds. The covalent bonds can be made in two different ways: either on the same DNA strand which will alter the shape permanently prevents other enzymes or molecules from binding t o it, or on adjacent strand therefore preventing replication/transcription process. (picture) The reaction happens in the N7-site of guanine, which is the most preferred nuclei acid. However the reaction can also take place at the N3-site of adenine. The alkylation of the nucleotide leads to miscoding of DNA as for example Thymine will bind to guanine instead cytosine. Due to the p-orbital of the benzene ring in melphalan that draws the lone pair electrons from nitrogen, this leads to reduction of reactivity to form the azirdine, hence only strong nucleophiles such as guanine will react with it. This has the benefit of reducing the side reactions with water, tissue and blood, leading to the drug can be given orally. The side chain of Melphalan is L-phenylalanine, meaning it has a component that act as the amino acid phenylalanine. (picture) Consequently the drug is most likely to be recognised as an amino acid, and it will be taken into the cell by transporter protein. This increase s the stability of the drug further. Optimization of Melphalan Despite Melphalan being used as an anticancer drug for over 50 years, it’s associated with many complications including poor solubility in water, variable bioavailability and rapid hydrolysis at physiological pH (11-14) which also increase the bioavailability problem. Another major problem is its rapid clearance from the blood circulation due to its short half-life (90 min). A study conducted in USA to tackle these difficulties by adding a poly ethylene glycol (PEG) to the Mel, in order to enhance the formulation of parental and oral administration. PEG is a synthetic polymer which is water soluble and non-ionic. It is an amphipilic polymer meaning it has an exceptional capacity to be soluble in both aqueous and organic solvents. This property makes it ideal for chemical conjugate of substance that has a biological effect. Another advantage of using PEG is it has exceptionally low level of antigenicity and immunogenicity. The process of conjugation is called PEGylation. Itâ₠¬â„¢s a two-step process where in the first step the activation and derivatization of PEG occurs with appropriate functional groups. In step two the conjugation of the activated PEG with Mel occurs. The NH2 group in melphalan undergoes a nucleophilic reaction with mPEG-succinimidyl propionate (mPEG-SPA) under the presence of DMAP catalyst. This reaction produces an amide bond, which is reasonably stable. The mPEG-SPA gets hydrolysed to mPEG and N-hydroxysuccinimide. Fig x. The study conjugated two molecular weight (MW) PEG: 2000 and 5000 Da. Variable test were conducted to measure the difference between the two different MW PEG conjugates and the parent drug Melphalan. The aqueous solubility of the conjugated Melphalan was measured by dissolution test, the results are shown in table 1. The table shows there is an increase in aqueous solubility of MpPEG-2000 by nearly 80 times reading as 7.2 ±0.12  µg/ml and increased by approximately 123 times for MpPEG-5000 reading as 11.07 ±0.8  µg/ml, compared to the measured solubility of the parental Melphalan of 0.09  µg/ml. This results can be explained due to the PEG chain being attached to the drug. On the other hand the haemolytic activity of melphalan versus its conjugates was also determined by assessing the haemoglobin content. The melphalan haemolytic activity was measured to 100% above the concentration 3.5  µg/ml (table 2). With regards to MpPEG-5000 only 48.8 ±1.5% haemolysis observed at concentration of 32  µg/ml (table 3). In case of MpPEG-2000 the highest percentage of haemolysis of 81.3 ±0.5% was recorded at concentration of 32  µg/ml (table 4). The lower haemolytic activity of the conjugates compared to melphalan might be due to the dominated property of polymeric carrier PEG. These results is an indication that the chain length of PEG plays an important role on the haemolytic activity. The property of delaying haemolysis is better in MpPEG-5000 compared to MpPEG-2000 even at higher concentrations. It also has an effect on the aqueous solubility due to the longer the chain the more hydrophilic backbone of PEG will be present. The percentage cumulative hydrolysis of the conjugates was observed in case of MpPEG-2000 to be 10.11 ±0.68 after 6 hours, whereas for MpPEG-5000 was only 5.21 ±1.2% after the same time (table 5). The low cumulative hydrolysis detected in MpPEG-5000 may be understood due to the ester linkage being protected by the PEG molecule du e to the steric hindrance. Furthermore the amide bond is more protected in MpPEG-5000 compared to MpPEG-2000 due to the shielding effect of the larger chain of PEG. Therefore the MpPEG-5000 can be an ideal candidate to provide a slow release drug formulation. Thus, increase the half-life of the drug and decrease the clearance. Clinical trials Conclusion This drug adds a small group, an alkyl group to the DNA to alter its structure and hence modifies the function. It’s an alkylating agent which means it adds an alkyl group to DNA. The alkyl group may be transferred as an alkylcarbocation, afree radical, acarbanionor acarbene(or their equivalents). Nitrogen mustards (NMs) form cyclic aminium ions (aziridinium rings) by intramolecular displacement of the chloride by the amine nitrogen. This aziridinium group then alkylates DNA once it is attacked by the N-7 nucleophilic center on the guanine base. A second attack after the displacement of the second chlorine forms the second alkylation step that results in the formation of interstrand cross-links (ICLs) as it was shown in the early 1960s. At that time it was proposed that the ICLs were formed between N-7 atom of guanine residue in a 5’-d(GC) sequence.[15][16] These kinds of lesions are effective at forcing the cell to undergo apoptosis via p53, a protein which scans the genome for defects. Note that the alkylating damage itself is not cytotoxic and does not directly cause cell death. For the analgesic treatment of multiple myeloma and for the palliation of non-resectable epithelial carcinoma of the ovary. Has also been used alone or as part of various chemotherapeutic regimens as an addition to surgery in the treatment of breast cancer, alone or in combination regimens for palliative treatment of locally recurrent or unresectable in-transit metastatic melanoma of the extremities, as well as for the treatment of amyloidosis with prednisone. http://www.bloodjournal.org.ezproxy.kingston.ac.uk/content/106/2/698 http://onlinelibrary.wiley.com.ezproxy.kingston.ac.uk/doi/10.1002/cncr.27820/full http://www.bloodjournal.org.ezproxy.kingston.ac.uk/content/117/24/6445 http://www.drugbank.ca/drugs/DB01042 http://cancerres.aacrjournals.org/content/44/7/2773.full.pdf+html http://pubs.acs.org.ezproxy.kingston.ac.uk/doi/full/10.1021/jo300351g http://www.bloodjournal.org.ezproxy.kingston.ac.uk/content/100/1/224 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4024156/ http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4286742/ http://ac.els-cdn.com/S0898656813000314/1-s2.0-S0898656813000314-main.pdf?_tid=c3b012a4-c411-11e4-944b-00000aab0f27acdnat=1425654312_d9351a386aa77b225426f1c34e100e88 http://ac.els-cdn.com/S0144861714004196/1-s2.0-S0144861714004196-main.pdf?_tid=00c4f2b8-c412-11e4-aee6-00000aab0f6cacdnat=1425654412_90fa9336c00ccddd1706b13914966246 http://ac.els-cdn.com/S0009279702000145/1-s2.0-S0009279702000145-main.pdf?_tid=458a0f50-c412-11e4-b306-00000aacb360acdnat=1425654528_8adc41f2576ed853db84f0b37d63aba7 http://ac.els-cdn.com/S0014827X03001642/1-s2.0-S0014827X03001642-main.pdf?_tid=8710dca6-c412-11e4-ba2b-00000aab0f02acdnat=1425654638_fb397da0e9304b218456d2a2da0cc6bf http://ac.els-cdn.com/S0144861714012533/1-s2.0-S0144861714012533-main.pdf?_tid=ffa7bf86-c412-11e4-9b6f-00000aacb361acdnat=1425654840_9033413b545510662226d20eec11b255 http://www.drugs.com/mmx/melphalan.html http://cancerres.aacrjournals.org/content/23/8_Part_1/1315.full.pdf http://www.hindawi.com/journals/jna/2010/543531/ https://books.google.co.uk/books?id=Sd6ot9ul-bUCpg=PA1208lpg=PA1208dq=nitrogen+mustard+aziridine+ringsource=blots=TMPCHHeGPrsig=tArK9BCztSsPXxLXMj2ojRGFG2shl=ensa=Xei=FggDVaHxFMatU_6zgfABved=0CD8Q6AEwBg#v=onepageqf=false Bifunctional alkylating agents (e.g., nitrogen mustards (melphalan, chlorambucil, cyclophosphamide, and ifosfamide) and chloroethylnitrosoureas (BCNU and CCNU)) possess two reactive sites. These agents cross-link DNA with proteins or, alternatively, cross-link two DNA bases within the same DNA strand (intrastrand cross-links) or on opposite DNA strands (ICLs). ICLs, which block replication forks, are the most serious cytotoxic lesions produced by most bifunctional drugs. Accordingly, the extent of ICLs correlates well with the cytotoxicity of nitrogen mustard drugs

Martyrdom and September 11th :: Martyr Islam Muslim 9/11 9-11 Terrorism Terrorist

On September the 11th 2001, the international crisis of terrorism exploded in America. The dark cloud that loomed over lower Manhattan eventually cleared but the reality of the American entrance into the battlefield of terror didn’t dissipate. When President Bush addressed his stunned and grieving nation, he declared a crusade on terrorists and all who harbored them, and â€Å"when [his] remarks were translated into Arabic for broadcast throughout the Middle East, the word crusade was rendered as ‘war of the cross’† (Carrol 5). This religious reference rang true to those terrorists who had attacked the World Trade Center; all were members of Osama Bin Laden's terrorist network Al Qaeda. The group is a militant Islamist organization that believes those who commit acts like those of September 11th are martyrs, welcomed into eternal paradise. The phenomenon of martyrdom is not exclusive to Islam. By definition, a martyr is â€Å"one who voluntarily suffers death rather than deny his religion by words or deeds; such action is afforded special, institutionalized recognition in most major religions of the world†¦the term may also refer to anyone who sacrifices his life or something of great value for the sake of principle† (Britannica). The word is derived from the Greek word for witness. Throughout the ages, willingness to die for a noble cause has been a persistent idea. In three of the world’s major religions- Judaism, Christianity and Islam, martyrdom has played a significant role. In Judaism, the concept of martyrdom is referred to as Kiddush Hashem which means sanctification of God's name. This definition includes refusal to renounce the word of God for reasons of convenience or to save one’s life. According to Judaic beliefs, Abraham, the first Hebrew patriarch, was thrown into a furnace for denouncing idolatry. Though he was saved by God, his brush with death made him the first martyr of the Jewish faith. During medieval times, Jews were persecuted by Christians throughout Europe, and were frequently put to death for crimes such as blood libel and host desecration1. Many Jews were forced to flee Spain during the Inquisition to avoid being unjustly persecuted under the pretense of similar offenses. These martyrs were usually burned at the stake. In the 1940’s Hitler systematically slayed over six million Jews during the reign of the Third Reich. These are just a few examples of martyrs of Judaism. In early Christianity, all believers were considered martyrs. Later, this distinction was reserved for those who refused to renounce their faith and suffered as a result, whether they were injured or killed. Eventually, only those who were killed for their beliefs were considered martyrs.

Technology - Digital Video and Copyright Fair Use Essay -- Exploratory

Digital Video and Copyright Fair Use Abstract: Video is one of the most compelling forms of communication of this time. Over the course of the past few years, the gradual but sure drift from analog to digital in video technology has not only improved the abilities of visual communication media to distribute data, but has also improved their abilities to manipulate the data that they distribute. Digital video technology has advanced to the extent that still image manipulation has been usurped by more powerful technological developments that allow elements of a video image to be manipulated in real-time. That is, objects or persons in a video image can be edited out or edited in while the image is in broadcast without the slightest glitch to suggest that some change has occurred; everything would look â€Å"real.† The advantages that this technology opens for visual media are extensive. Similar to some technologies, however, it opens up an exploitive edge. Pixels are plastic (can be changed) and using them to distort or mani pulate reality is an opportunity open to all users of video manipulation tools. The ethics of such uses and the social considerations of how copyright laws would deal with a technology which manipulates digital works of authorship, works to which copyright automatically attaches, are issues worth considering. This paper explores the possible and actual, reputable and less reputable uses of this technology in an attempt to stimulate discussions about how â€Å"well-intended† technologies can be utilized by users in unethical and harmful ways. The paper also attempts to see where possible infringements of copyright’s fair use doctrine has occurred or could possibly occur through use of this technology. A n... ...pinions. Despite the many issues connected to this technology however, the advantages it offers surpass any disadvantages seen thus far. References 1. Amato, Ivan. Lying with Pixels, Technology Review, Cambridge, Jul/Aug 2000. p.61. 2. See reference 1 above. 3. See reference 1, p.62. 4. See reference 3 above. 5. Royal Philips Electronics, Imaging : its digital future, Briefing, Volume 3, Issue 2, article no. 19. 6. See reference 1, p.64. 7. See reference 1 p. 65. 8. Samuelson, Pamela. Copyright’s fair use doctrine and digital data, Association for Computing Machinery., Communications of the ACM; vol. 37, Issue 1; New York, 1994. p. 22. 9. See reference 8, p.23. Additional:- Samuelson, Pamela. Copyright and Digital Libraries. (class material)http://web5.computer-select.com/csweb/session/329/331/ (Article - Free Video Hosting)

Critical Analysis Essay Essay

This section contains a summary of the article â€Å"What Cost Chris Dussold His Dream Job?† In his introduction, Bartlett explains how Mr.Dussold was a professor at Southern Illinois University at Edwardsville and was fired for â€Å"copying another professor’s teaching statement.† But further explains that Mr.Dussold says â€Å"that was not the real reason he was fired† and that â€Å"Now Mr.Dussold is on a crusade to restore his reputation†¦Ã¢â‚¬  he goes on to explain how Mr.Dussold lands the dream job he wanted which was going smoothly until one day when a rumor started. Mr.Dussold tries many ways to make the rumor stop happening and assure everyone it is not true. Bartlett tells you about how the university does investigations on the rumor and what Mr.Dussold does to try and clear his name. Describing later on how the investigation ended and explain why Dussold ends up suing the college for false termination. Arguments See more: how to write a critical analysis outline The main purpose of this article written by Bartlett is to help prove the innocence of Mr.Dussold and give the side of Dussold’s story behind the rumor made against him. Trying to make an ethical argument Bartlett tells how Dussold’s reputation is put into question. According to the article Bartlett describes how Dussold had gone to Southern Illinois as a student and had offers from other colleges to work there but took the job at SIUE because â€Å"It felt like coming home.† In fact he said â€Å"‘I used to tell them I would take this job for nothing,’† and how many of his students and colleagues enjoyed working with him. Dussold tried to steer clear of arguments with others and then out of nowhere a rumor is started the ruins his character as a teacher. Bartlett also elucidates that Dussold whole life started changing after this rumor had been started. The author states that Dussold who was once an outgoing professor but once the rumor started, allegations were made about  him which led him to start questioning everyone and everything around him â€Å"Every interaction now carried a question mark: Who believes the rumor?†¦Were there more?† Each day these questions were rattling around in his head, not knowing the answer to any of them. Eventually he starts going into his own shell trying to not cause any more problems in his life â€Å"The once-outgoing professor started keeping to himself.† The rumors started making Dussold stressed showing us an emotional argument. Author Style Bartlett starts out describing how Dussold has told this story many times, saying how he was fired, how he was escorted and how he felt hopeless. â€Å"But even after two years and numerous retellings, the emotion still sneaks up on him.† But does not give the full story away making you curious and wanting to read more. He also goes on to mention that he was fired for â€Å"plagiarism† but he felt that, that was not the true reason. Dussold believes the reason is because a rumor that had start but was not true, and vouched to clear his name. â€Å"No matter what you think of Mr. Dussold†¦you can’t dent his zeal: He is a man on a mission.† Though Bartlett tells you this information he still leaves out the main details like what the rumor is or how Mr. Dussold is going to prove his side of the story making this an intriguing contradiction. Bartlett writes this story in order of the events that had happened besides his brief explanation in the introduction. In the first passage of this article Bartlett explains how Dussold used to be a student at SIUE and was ecstatic when he was offered a job there â€Å"’I used to tell them I’d take this job for nothing,’† going on to say how he and his colleagues as well as his students were getting along well and his life was going good. Later on you find out about how Dussold’s life has been turned upside down due to a rumor starting accusing him of having sexual activities with a student that was in one of his after school clubs, †Every interaction now carried a question mark,†. Eventually you learn that Dussold get the dean involved who does his own investigation and later on fires but not for the rumor, but because of plagiarism of another professors work. Dussold turns back around after getting fired and sues them because he believes he was truly fired because of the rumor, and how he now has a new job and a college not far from SIUE, â€Å"He remains convinced that it was the rumor-and the fear that he  would sue-that led to his firing. And he believes he can prove that in court.† Response This story was unconvincing due to the fact that Bartlett says Dussold claims to be fired because the rumor was started. Then Bartlett just explains everything surrounding the rumor and never exaggerates on the actual reason he got fired, which was plagiarism. It is also unbelievable since it says Ms. Peyla, the student from the rumor, decided at one point to just go on with the rumor and report that it was true. Not many people would willingly just agree with a rumor that is potentially life ruining if it were not true. This article could have been more convincing if other professors or students had been included in the story. This would have helped because the more witnesses the more proof of what really happened and that usually would help in deciding if a person is guilty or not judging from an article about their situation.