Introduction To Magnetic Coupling Engineering Essay

Two music directors are denoted to as inductively coupled or magnetically coupled when they are constructed such that alteration in current flow through one wire induces a electromotive force across the terminals of the other wire through electromagnetic initiation. The measure of inductive matching between two music directors is measured by their common induction. The yoke among two wires can be increased by weaving them into spirals and puting them near together on a common axis, so the magnetic field of one spiral passes through the other spiral. The two spirals may be physically enclosed in a individual unit, as in the primary and secondary sides of a transformer, or may be separated. Yoke may be intended or unintended. Unintentional yoke is called cross-talk, and is a signifier of electromagnetic intervention. Inductive matching favours low frequence energy beginnings. High frequence energy beginnings by and large use capacitive yoke. An inductively coupled transponder involves an electronic informations transporting device, normally a individual micro chip, and a big spiral that maps as an aerial. Inductively conjugate transponders are about ever operated inactively.UsesDevicess that use inductive yoke comprises:TransformersA transformer is a device that handovers electrical energy from one circuit to another through inductively coupled conductors-the transformer ‘s spirals. A altering current in the first or primary twist creates a variable magnetic flux in the transformer ‘s nucleus, and therefore a variable magnetic field through the secondary twist. This altering magnetic field induces a fluctuating electromotive force ( EMF ) or â€Å" electromotive force † in the secondary twist. This consequence is called common initiation. If a burden is connected to the secondary, an electric current will flux in the secondary twist and electrical energy will be transferred from the primary circuit through the transformer to the burden. In an ideal transformer, the induced electromotive force in the secondary twist ( VS ) is in proportion to the primary electromotive force ( VP ) , and is given by the ratio of the figure of bends in the secondary ( NS ) to the figure of bends in the primary ( NP ) as follows: By appropriate choice of the ratio of bends, a transformer therefore allows an jumping current ( AC ) electromotive force to be â€Å" stepped up † by doing NS greater than NP, or â€Å" stepped down † by doing NS less than NP. In the huge bulk of transformers, the twists are coils lesion around a ferromagnetic nucleus, air-core transformers being a noteworthy exclusion. Transformers range in size from a thumbnail-sized yoke transformer hidden inside a phase mike to immense units weighing 100s of dozenss used to complect parts of power grids. All operate with the same basic rules, although the scope of designs is broad. While new engineerings have eliminated the demand for transformers in some electronic circuits, transformers are still found in about all electronic devices designed for family ( â€Å" brinies † ) electromotive force. Transformers are indispensable for high electromotive force power transmittal, which makes long distance transmittal economically practical.Electric motors and generatorsAn electric motor uses electrical energy to bring forth mechanical energy, really typically through the interaction of magnetic Fieldss and current-carrying music directors. The contrary procedure, bring forthing electrical energy from mechanical energy, is accomplished by a generator or dynamo. Grip motors used on vehicles frequently perform bot h undertakings. Many types of electric motors can be run as generators, and frailty versa. Electric motors are found in applications every bit diverse as industrial fans, blowers and pumps, machine tools, family contraptions, power tools, and disc thrusts. They may be powered by direct current ( for illustration a battery powered portable device or motor vehicle ) , or by jumping current from a cardinal electrical distribution grid. The smallest motors may be found in electric wrist watchs. Medium-size motors of extremely standardized dimensions and features provide convenient mechanical power for industrial utilizations. The really largest electric motors are used for propulsion of big ships, and for such intents as grapevine compressors, with evaluations in the 1000000s of Watts. Electric motors may be classified by the beginning of electric power, by their internal building, by their application, or by the type of gesture they give. The physical rule of production of mechanical force by the interactions of an electric current and a magnetic field was known every bit early as 1821. Electric motors of increasing efficiency were constructed throughout the nineteenth century, but commercial development of electric motors on a big graduated table required efficient electrical generators and electrical distribution webs. Some devices, such as magnetic solenoids and speaker units, although they generate some mechanical power, are non by and large referred to as electric motors, and are normally termed actuators and transducers, severally.Induction loop communicating systemsInduction cringle is a term used to depict an electromagnetic communication- and sensing system, trusting on the fact that a traveling magnet will bring on a electrical current in a nearby conducting wire. Induction cringles are used for transmittal and response of communicating signals, or for sensing of metal objects in metal sensors or vehicle presence indexs. A common modern usage for initiation cringles is to supply hearing aid to hearing assistance users.Artworks tabletA artworks tablet ( or digitising tablet, artworks pad, pulling tablet [ 1 ] ) is a computing machine input device that allows one to hand-draw images and artworks, similar to the manner one draws images with a pencil and paper. These tablets may besides be used to capture informations or handwritten signatures. A artworks tablet ( besides called pen tablet or digitiser ) consists of a level surface upon which the user may â€Å" pull † an image utilizing an affiliated stylus, a pen-like drawing setup. The image by and large does non look on the tablet itself but, instead, is displayed on the computing machine proctor. Some tablets nevertheless, come as a operation secondary computing machine screen that you can interact with straight utilizing the stylus. Some tablets are intended as a general replacing for a mouse as the primary pointing and pilotage device for desktop computing machines.Radio Frequency IdentificationRadio-frequency designation ( RFID ) is the usage of an object ( typically referred to as an RFID ticket ) applied to or incorporated into a merchandise, carnal, or individual for the intent of designation and tracking utilizing wireless moving ridges. Some tickets can be read from several metres off and beyond the line of sight of the reader. Radio-frequency designation comprises inquisitors ( besides known as readers ) , and tickets ( besides known as labels ) . Most RFID ticket contain at least two parts. One is an incorporate circuit for hive awaying and treating information, modulating and demodulating a radio-frequency ( RF ) signal, and other specialised maps. The 2nd is an aerial for having and conveying the signal.Inductive ModemsResonant energy transportationResonant energy transportation or resonating inductive yoke is the short-distance wireless transmittal of energy between two spirals that are extremely resonating at the same frequence. The equipment to make this is sometimes called a resonating transformer. While many transformers employ resonance, this type has a high Q and is about ever air-cored to avoid ‘iron ‘ losingss. [ commendation needed ] The spirals may be present in a individual piece of equipment or in separate pieces of equipment. Resonant transportation plants by doing a spiral pealing with an hovering current. This generates an oscillatory magnetic field. Because the spiral is extremely resonating any energy placed in the spiral dies off comparatively easy over really many rhythms ; but if a 2nd spiral is brought near to it, the spiral can pick up most of the energy before it is lost, even if it is some distance off. One of the applications of the resonating transformer is for the CCFL inverter. Another application of the resonating transformer is to match between phases of a superheterodyne receiving system, where the selectivity of the receiving system is provided by tuned transformers in the intermediate-frequency amplifiers. [ 1 ] Resonant transformers such as the Tesla spiral can bring forth really high electromotive forces without curving, and are able to supply much higher current than electrostatic high-potential coevals machines such as the Van de Graaff generator. [ Inductive charging merchandises charge batteries utilizing inductive yoke, such as eCoupled ; Torches, Cochlear Implants and many electric toothbrushes. Inductive charging uses the electromagnetic field to reassign energy between two objects. A bear downing station sends energy through inductive yoke to an electrical device, which shops the energy in the batteries. Because there is a little spread between the two spirals, inductive charging is one sort of short-distance radio energy transportation. The other sort of charging, direct wired contact ( besides known as conductive charging or direct yoke ) requires direct electrical contact between the batteries and the courser. Conductive charging is achieved by linking a device to a power beginning with plug-in wires, such as a moorage station, or by traveling batteries from a device to courser. Initiation coursers typically use an initiation spiral to make an alternating electromagnetic field from within a bear downing base station, and a 2nd initiation spiral in the portable device takes power from the electromagnetic field and converts it back into electrical current to bear down the battery. The two initiation spirals in propinquity combine to organize an electrical transformerInitiation cookers and initiation warming systemsAn initiation cooker uses a type of initiation warming for cooking. It is chiefly distinguished from other common signifiers of stovetop cookery by the fact that the heat is generated straight in the cookery vas, as opposed to being generated in the stovetop ( as by electrical spirals or firing gas ) and so transferred to the cooking vas. In an initiation stovetop, a spiral of Cu wire — an electromagnet — is placed underneath the cookery pot. An oscillatory current is applied to that spiral, which produces an oscillatory magnetic field. That magnetic field creates heat in the cooking vas over it, in two different ways. First, it induces a current in the electrically conductive pot, which produces Joule ( I2R ) heat. Second, it besides creates magnetic hysteresis losingss in the ferromagnetic pot. The first consequence dominates: hysteresis losingss typically account for less than 10 per centum of the entire heat generated. [ 1 ]Low frequence initiationLow frequence initiation is an unwanted signifier of inductive yoke, which can happen when a metallic grapevine is installed parallel to a high-potential power line. The grapevine, which is a music director, and is insulated from the Earth by its protective coating, can develop electromotive forces which are risky to personnel runing valves or otherwise rea ching the grapevine.Significance and Applications.Magnetic yokes are used to convey rotational and/or additive gesture without direct contact and Rotary yokes Linear yokes Hysteresis yokes Eddy current yokes Rotary yokes are chiefly used to extinguish the usage of seals in revolving and reciprocating machines, such as seal-less pumps and pistons.A Use of magnetic couplings improves the dependability and safety facets of such machines because seals are prone to deterioration over clip and cause leaks. Rotary magnetic couplings used in these applications are designed in two constellations – co-axial and face-to-face.A A In the co-axial constellation, the two halves of the coupling are mounted co-axially with each other and nested one within the other.A The outer member is typically connected to the motor and the interior member to the driven system, for illustration, the pump in a seal-less pump. A cup-shaped stationary member, mounted to the pump organic structure, resides between the driver and follower and separates the fluids on the pump side from the environment on the motor side.A Materials for the barrier cup and exposed surfaces of the follower are chosen to last uninterrupted contact with the fluids being pumped.A The thickness of the barrier is designed to defy any force per unit area derived function without important distortion. Face-to-face type yokes are used where axial length is at premium and some misalignment demands to be tolerated.A The two pancake-shaped parts consisting this type of coupling have magnets mounted on the close faces.A The separation barrier in this instance can be every bit simple as a level wall.A One facet of face-to-face type yokes is considerable attractive force between the two members. Linear and rotary magnetic yokes, and loanblends of the two, besides find application in vacuity engineering where place or gesture must be transmitted across a vacuity barrier.A An added consideration in these applications is stiffness of the yoke ; minimising the slowdown between driver and follower.A Linear magnetic yokes, following similar rules, allow precise control of robotics inside vacuity systems.A These couplings are used in the semiconducting material industry to place objects within a clean chamber. Elimination of seals and decrease of the figure of constituents inside the chamber improves taint control and enhances system dependability. In all the above instances, greater torque/force capacity is realized with stronger magnets, increased diameter and decreased radial gap.A An added consideration in these designs is the stiffness of the matching which consequences in more precise control.A Devices operating at elevated temperatures ( & gt ; 120 A °C ) typically employ Sm-Co magnets while others may utilize Nd-Fe-B or ceramic magnets. Hysteresis yokes are typically used where a torsion modification is needed, such as in the bottle cresting industry.A Eddy current couplings exhibit torsion that increases linearly with increasing revolutions per minute.A They are frequently employed in clasps and in couplings where utmost misalignment demands to be tolerated.A Hysteresis and eddy current rules may besides be used in the design of additive couplings. Magnetic Yokes are used in the industry to convey torsion through a spread. This spread is the distance between two members of the yoke. Between this spread, one may hold air, vacuity, fluids, centrifuge cups, or other similar points. There are two basic constellations that are utilized ; the Axial and Radial design. The Axial design requires that the two magnet systems face each other, similar to two battercakes confronting each other. As one member rotates, the other follows. The maximal torsion will be determined by many factors, such as air spread, figure of poles, stuffs selected, working temperature, etc. The Radial design requires that the magnet systems are homocentric to each other. As one member, typically the outer rotates andA the other follows. When choosing the barrier stuff between the matching members, see eddy current effects, since the flux lines of the magnetic yoke will cut the barrier material.A Conductive stuffs will get down to heat as the RPM is increased.A Conductive stuffs used as the barrier stuff will take opposition of the matching gesture, as some of the input work will turn into the eddy current losingss ( heat ) .A At higher RPM, over 600 RPM, this loss can be important. Typically, matching assemblies do non be as a standard â€Å" off the shelf † point. They have to be designed for each application, so manufactured. Depending on the complexness of your design, technology charges may use. If you are able to utilize a constellation that is near to something that we already have designed, and you are non concerned about â€Å" optimising † the constellation, engineering/design charges will non use. Yokes may be hermetically sealed so that they may work in rough environments, such as chemical applications.A Applications of magnetic yokes include atomic environments, chemically risky environments, high temperature environments, oil boring applications ( downhole ) , vacuity applications, andA quiver isolation applications. Industries that have benefited from magnetic yokes include aerospace, medical, chemical, pharmaceutical, nutrient, biotechnology, industrial ovens, compressors, metering, A A and fluid mechanicss, because magnetic yokes are the lone device that can convey contact free torsion.Magnetically-Coupled CircuitsA current i1 at L1 produces opencircuit electromotive force v2 at L2. A current i2 at L2 produces an unfastened circuit electromotive force v1 at L1. Current come ining the flecked terminus of one spiral produces a electromotive force that is sensed positively at the flecked terminus of the 2nd spiral. Current come ining the undotted terminus of one spiral produces a electromotive force that is sensed positively at the undotted terminus of the 2nd spiral. ( a ) A circuit incorporating common induction in which the electromotive force ratio V2/ V1 is desired. ( B ) Self and common inductions are replaced by the corresponding electric resistances. Zin = Zp + jw L1 + w 2M2/Jw L2 + ZsTransformerA given transformer which is to be replaced by an tantamount web. The T equivalent. M & lt ; = under root of L1L2 The yoke coefficient K is M /under root of L1L2Inductive YokeInduction â€Å" Liter † depends on circuit geometry and medium belongings â€Å" Liter † has intending merely for a closed circuit. However when talk about induction of merely a portion of a circuit, we means the part that a section of a circuit brand ti the entire induction of the closed circuit If sinusoidally, VN = J tungsten B A cosI? Induced noise depends on the country enclosed by the distributed circuit ( VN = J tungsten B A cosI? Or VN = J tungsten M I1 = M vitamin D i1 / vitamin D T Magnetic matching between two circuits Magnetic matching between two circuits Suppression technique: separation circuit ( Ba† Ã¢â‚¬Å" ) ; writhing ( B canceling ) closer to land plane ( Aa† Ã¢â‚¬Å" ) orientation ( cosI?a† Ã¢â‚¬Å" ) Comparison between inductive and capacitive yoke a‘ Capacitive yoke: noise picked up is decreased when electric resistance a† Ã¢â‚¬Å" , but inductive yoke non a‘? Noise electromotive force is produced in series with receiver music director in magnetic field yoke, while in electric field matching noise electromotive force is produced between receiving system and land Magnetic yoke when a shield is placed around the receiving system ( with ungrounded and nonmagnetic shield ) still VS = J tungsten M1S I1 and VN = J tungsten M12 I1 Decision: Even screen grounded at one terminal has no effects on the magnetically induced electromotive force in the centre music director A § 3.5 Magnetic Coupling Between Shield and Inner Conductor Magnetic yoke between a hollow conducting tubing and music director placed inside it Magnetic field produced by current in a cannular music director No field indoors pit Coaxial overseas telegram with shield current flowing so Ls = M Condition: The cogency of above depends merely on the fact that there is no magnetic field in the pit of the tubing due to screen current. Noise electromotive force VN due to screen current Equivalent circuit of the shield music director VN = J tungsten M IS Since Sing M = Ls Finally secret plan of noise electromotive force in shielded music director due to screen current Notes: Break frequence is defined as the shield cutoff frequence

Industrial Revolution facts, information Essay

Industrialisation is a period in which machines take place instead of men. It is the period in which machines do work once done by humans. This is basically time period from which the agrarian society transform into an industrial society. Background: Industrialisation took place in the mid of 18th century to early 19th century in mainly Europe and North America; starting in Great Britain followed by Germany, Belgium, and France. During this time period industries played a vital role in the urbanization of Europe. It was a shift from rural work to industrial labor. Mostly labor before industrialization used to work on their own, things were mostly handmade which took many time and labor. Industrialisation helped the poor community in different aspects of saving time as well as energy. The transformation from an agricultural economy to industrial economy is known as Industrial Revolution. Industrialisation had played the vital role in the construction of new society in Europe. As industrialization changed scenario of society but also bring devastation to the society because Capitalism emerged during industrialization which made rich community more richer and poor community poorer. Howard Zinn once said â€Å"Capitalism has been always the failure for the lower classes. It is now beginning to fail for the middle class†. Such various observers as Karl Marx and Émile Durkheim cited the â€Å"alienation† and â€Å"anomie† of individual workers faced by seemingly meaningless tasks and rapidly altering goals. The fragmentation of the extended family and community tended to isolate individuals and to countervail traditional values. By the very mechanism of growth, industrialism appears to create a new strain of poverty, whose victims for a variety of reasons are unable to compete according to the rules of the industrial order. In the major industrial ized nations of the late 20th century, such developments as automated technology, an expanding service sector, and increasing suburbanization signaled what some observers called the emergence of a postindustrial society. Industrialisation in Thomas Hardy’s novel â€Å"Tess Of The D’Ubbervilles†: When Thomas Hardy was born in 1840, agriculture was the most important industry in England, employing roughly 20% of the labor force. By 1900, however, agricultural workers comprised less than 10% of the total workforce. Hardy witnessed much of this hardship as a child growing up in Dorset–which would later become his model for Wessex. Hardy’s Dorset was, in fact, the poorest and least industrialized county in Britain, and the farm laborers led difficult, often unrewarding lives. Laborers toiled from six o’clock in the morning until six o’clock at night in the summer and from the first light until dusk in the winter. It was not uncommon to find women and children in the fields; their labor was frequently used as the cheap substitute for men’s. Their diet was monotonous and meager–bread, bacon and cheese, and only occasionally milk. They drank beer and tea, and those who could not afford tea would soak burnt toast in water. In addition, the li ving conditions of many of these laborers were horrendous. Many lived in squalor and did not have the money to improve their condition. In 1851, there were half a million such laborers in England. Thomas Hardy’s Tess of the d’Urbervilles (1891) contains complex and detailed interrogations of many Victorian values and of the capitalist culture of his time. This novel is a fierce condemnation of the social, ethical, moral, religious, and political values held by the majority of Hardy’s cultural elite contemporaries in England. The most obvious example of Hardy’s cultural criticism is his assertion in the novel’s subtitle that Tess is â€Å"A Pure Woman.† By traditional Victorian standards, Tess is a fallen woman and as such is considered damaged goods suitable for the lowest bidder. Hardy is radically departing from these values by proclaiming Tess’s purity and virtue even though she has had sexual relations outside of marriage. It is, therefore, not surprising that initial reaction to the novel was highly negative. This cultural criticism is one of Hardy’s many challenges to the social conventions and values of his time found within this text. Tess’s struggle with Alec is both a gender and a class conflict. The text uses Tess’s relationship with Alec to expose the similarities and interconnections between a man’s physical and emotional oppression of a woman, on the one hand, and a more powerful social class’s economic oppression and destruction of a weaker class, on the other. Hardy’s Tess laments the destruction of the independent rural artisan class and blames nouveaux rich capitalist society for this degradation. Hardy goes on to condemn the industrialization of agricultural work because of what he views as the extremely destructive impact of technology and mechanization upon the quality of the rural workers’ lives. Hardy is also extremely critical of organized Christianity in several places throughout the novel, including the scene in which S orrow is actually denied a Christian burial. Hardy also raises questions about the injustice and inequality of a legal system, which finds Alec innocent of any wrongdoing but sentences Tess to death. Hardy clearly defines Tess as a member of the independent rural artisan class, a group whose way of life as a whole he asserts is at risk of extinction and whose quality of life is in decline due to capitalist economic forces and the industrialization of agricultural labor . He writes: â€Å"The village had formerly contained, side by side with the agricultural labourers, an interesting and better-informed class, ranking distinctly above the former – the class to which Tess’s father and mother had belonged – and including the carpenter, the smith, the shoemaker, the huckster, together with nondescript workers other than farm-labourers; a set of people who owed a certain stability of aim and conduct to the fact of their being life-holders like Tess’s father, or copyholders, or, occasionally, small free-holders. But as the long holdings fell in they were seldom again let to similar tenants, and were mostly pulled down†. (435) Hardy’s description of Alec’s family embodies all that Hardy maintains is wrong with capitalist nouveau riche society: there, money and status are more valuable and significant than people. Industrialisation in Charles Dicken novel â€Å"David Copper Field†: Charles John Huffam Dickens was born on 7 February 1812 in Portsmouth, the second of eight children. When he was nine years old his father was imprisoned for debt and all of the family except for young Charles were sent to Marshalsea, the debtors’ prison. Charles instead went to work in a blacking factory and suffered first hand the appalling conditions, loneliness, and despair. During his lifetime – he died in June 1870 – industrialization dramatically reshaped Britain, the population of London tripled and he saw the birth of the railways, the telegraph, and the steamship. He used his novels to bring to attention the social ills and abuses of Victorian England in such a way that the general public could relate and react to. For example, Oliver Twist attacked the workhouse system and portrayed a criminal underclass that captured the public’s imagination. In David Copperfield and Great Expectations, he drew on his early experiences of the debtors’ prison and the blacking factory. He exposed the brutal Yorkshire schools in Nicholas Nickleby and the inadequacies of the law in Pickwick Papers and Bleak House. The main reasons, therefore, were the mostly bad living conditions of the lower classes in factory cities, the automation of industry and the huge birth surplus in the country all throughout Great Britain. Furthermore, there were waves of migration into the huge cities and more and more capitalists that could be found in parliament, widely supporting political industrialization, completely neglecting the working conditions of their employees. In the Early Victorian Social Novel (1830 – 1850), the industrial system was to blame for the bad living conditions of the workers. However, it was not considered an abstract but rather manifested itself in individuals, like good and bad factory owners, responsible and irresponsible ones. And there was an unshakeable belief in morality and that those who were bad could be converted to good ones, those who were irresponsible could be made responsible. The authors at that time drew less attention to the details of the world of work and its machines, but rather preferred the depiction of physically and mentally injured people, because of their work. Therefore many metaphors were used to describe the prevailing social conditions, such as â€Å"Jungle of Work†, â€Å"Prison of Work† or â€Å"Subjugation of the worker through the machine†. Thinking of â€Å"Social Criticism†, huge institutions in society, like workhouses, industrialized cities or even certain governmental systems might occur to one’s mind in the first place. But many people forget that the smallest â€Å"institution† in society is the family. And the first socio-critical element in â€Å"David Copperfield† to begin with shall be the family itself. Therefore one has to know that families in the 19th century, especially in higher social classes, were organized completely differently than families are today. Usually, the husband was the â€Å"big boss† in the house, whereas the woman had to be the â€Å"good housewife and mother† who had to obey her husband. And the children, above all boys, normally were educated very strictly, and once out of the age in which they had to be cared for by their mother, they were completely under their father’s control and influence. Dickens’ now wants to criticize th is more or less â€Å"old-fashioned position† in his novel, but therefore he has to set up the right situation. The orphanage was an important topic at the time of industrialism because many parents had to work very hard and there were bad working conditions in the factories or workhouses. Subsequently, the parents were often physically worn out, many mothers not rarely died during or shortly after the birth of their children, and many fathers often died during their difficult, inhuman and most dangerous work. And the children they left were orphans, many of them still too young to care for themselves and facing a world they were not ready for, yet. And this topic of the orphanage is also raised in David Copperfield. As already David’s father is dead yet and his mother dies shortly after the birth of her second child, presumably suffering from the tortures of her cruel husband. Dickens was not the first novelist to draw the attention of the reading public to the deprivation of the lower classes in England, but he was much more successful than his predecessors in exposing the ills of the industrial society including class division, poverty, bad sanitation, privilege and meritocracy and the experience of the metropolis. In common with many nineteenth-century authors, Dickens used the novel as a repository of social conscience. The novel directs this ironical attack at the Victorian public opinion, which was either unaware or condoned such treatment of poor children. Dickens was critical about the Victorian education system, which is reflected not only in Nicholas Nickleby, Hard Times and Our Mutual Friend but also in his journalism and public speeches. As a boy, he was shocked to read reports about the cheap boarding schools in the North. In Nicholas Nickleby Dickens describes abusive practices in Yorkshire boarding schools. However, Dickens does not only criticise the malicious education system, but he is primarily concerned with the fates of these unfortunate children who are representatives of the most vulnerable portion of the society.

Portfolio of Chinese contemporary artist Cai Guo-Qiang

Cai Guo-Qiang is a Chinese contemporary artist, curator and internationally recognized as a creator of large scale explosion events. He was born in Quanzhou City, Fujian Province, China in 1957 and lives and works in New York. From 1982-1985 he trained in stage design at Shanghai Drama Institute.His practices on wild life, Chinese medicine, fire works and gun powder. He explored the properties of gunpowder in his drawings when he was in Japan from 1986 to 1995. In 1996 he was selected for finalist for Hugo Boss Prize and in 1999 in 48th Venice Biennale he holds the Golden Lion award and he was awarded the 7th Hiroshima Art Prize in 2007. In 2009, he was awarded the 20th Fukuoka Asian Culture Prize[1].The Chinese art was influenced by the New Culture Movements of Western techniques. The aim of new Chinese art is to make contemporary Chinese art accessible to a global audience. For these; it presents several portfolios with 100 contemporary Chinese artists. Some of the selected exhibit ions and projects of China are I Want to Believe, Stage One and Illusion, Explosion Project for the Festival of China, Louisiana Museum of Modern Art and Flying Dragon in the Heavens.Cai Guo-Qiang was first exhibited by the Guggenheim in 1996. I want to believe is the first solo exhibition of an Asian artist organized by Guggenheim Museum of Bilbao in 2009. It is funded by the National Endowment for the Arts and some additional individuals and foundations support. This exhibition charts the artist’s creation of gunpowder drawings, explosion events and social projects and promotes the understanding of Chinese arts and culture worldwide[2].  If there is no action the artistic work of Cai Guo – Qiang is nothing. â€Å"I want to believe† is the creative body work with illustration and visually. It is about the pain and bliss of aggressive explosions–celebratory fire-works versus deadly car bombs.â€Å"I want to believe† significance comes from modern ity, secularism and human kind. â€Å"I want to believe† shows the truth of the era and also increase the awareness. â€Å"I want to believe† is the creation and innovation of the intelligence. â€Å"I want believe† got the concentration of the cross cultures.â€Å"I want to believe† is the artistic art work. It got the interest of the viewers without artist’s intention.   â€Å"I want to believe† is the â€Å"explosion event† by Cai. To show pure energy force Cai used fire works in â€Å"I want to believe†. It is the great art of work with energy.â€Å"I want believe† is know for its explosives. It’s the combination of gunpowder, explosives etc. It shows 80 artistic works from past to present. It is also consists installations and social projects. I want to believe is the magnificent and famous work by Cai[3].â€Å"I want to believe† is the combination cultures and creation. His works are hugely inspired from locations. He explores wide variety art forms .He is best known for his â€Å"fire works†All his works are got inspired from ancient cultures of Chinese. His works mentions Buddhism and martial arts frequently. His works always speaks about the fight between human and nature. His work also mentions about Maoist and Taoist themes. His work is expensive in market of power and product.â€Å"I want to believe† is huge with sight and sound of explosions. It speaks about the artistic work of the art. I want to believe is the work of revolution and aggression[4].Conclusion:Cai Guo – Qiang is an extraordinary artist of twenty first century. He is a transnational artist of extraordinary creative vision and illustration, his structure are inherently unstable, dealing with expenditure of materials and ideas of transformation.Although his work is very expensive to imagine and also to realize his works always speaks about wide variety of aspects such as Capitalism, Sec ularism, Martial arts, Buddhism, Maoist, Taoist, Cross cultures, Transformation etc .His work also shows the combat between the nature and man.Reference:Gersh-Nesic, Beth S. â€Å"Cai Guo-Qiang: I Want to Believe†. Arthistory.about. 2008. Web. 2 June. 2010. Guggenheim. â€Å"Guggenheim Museum Presents Cai Guo-Qiang: I Want To Believe† Guggenheim. 21 May, 2008. Web. 2 June 2010. .Guo-Qiang's, Cai. â€Å"Biography†. Pbs. 2007. 2 June 2010. Smith, Roberta. â€Å"Cars and Gunpowder and Plenty of Noise† The New York Times. 22 February. 2008.[1] Guo-Qiang's, Cai. â€Å"Biography†. Pbs. 2007. 2 June 2010.   [2] Guggenheim. â€Å"Guggenheim Museum Presents Cai Guo-Qiang: I Want To Believe† Guggenheim. 21 May, 2008. Web. 2 June 2010. .[3] Gersh-Nesic, Beth S. â€Å"Cai Guo-Qiang: I Want to Believe†. Arthistory.about. 2008. Web. 2 June. 2010. [4] Smith, Roberta. â€Å"Cars and Gunpowder and Plenty of Noise† The New York Times. 22 Febru ary. 2008.   

Physical Mettalurgy of engineering materials Essay

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National Branding vs Private Label Branding Essay

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Aim in Life Essay Example for Free

Aim in Life Essay Most people in the world have some ambitions in life. A petty merchant has an ambition to become a big business man, a clerk to be a high officer, a student to be a doctor or engineer. Some desire for wealth, some desire for fame and reputation. A proper aim in life keeps a person shining and glowing in his future life. My aim in life is neither to collect money this or by that way nor for fame. It is my desire to become a well qualified doctor or a scientist. I do not just wish to be an ordinary doctor who spends his times in his laboratory trying to find out new drugs and medicines to remove the suffering of millions of people. The world remembers with thankfulness the name of the man who gave to the world vaccination. The world will remember forever the man who gave us penicillin. As a doctor it is my real wish to server the badly suffering humanity too. Our country is still under development and it has become necessary for all of us, especially for doctors to acheive sound progress in the field of new drugs and medicines, And for the prosperity and solidarity of pakistan we should work hard with spiritual zeal and zeast. I have an ambition to do something in this world so great as the doctors and the courages founders did in the past. I would like to give the world some new drugs and injections that will cure some of the many disease that people are still suffering from. In my opinion, wealth, fame and any other kind of materialistic gain are hollow and baseless if earned through unfair means. In my ambition, it is great wish to help the suffering people. For lawful earnings it will be my foremost dut to server the humanity, by going to the rural areas of this under developed country in order to help the poor and humble people for their happiness and entire satisfaction.

Cell-cell Interaction in Embryo Development

Cell-cell Interaction in Embryo Development The formation of vulva depends upon a second round of cell-cell interaction. The anchor cell (located in the gonad) and six precursor cells (located in the skin adjacent to the gonad) are involved in this interaction. The precursor cells are collectively called Pn.p cells, which contains cells named as P3.p to P8.p. The fate of these cells is determined by its position relative to the anchor cell. The developmental pathways of these cells are presented in Fig.11.8. During third larval stage, the lin-3 gene is activated in the anchor cell, and produces the signal protein LIN-3, which is related to vertebrate epidermal growth factor (EGF). The precursor cells express a receptor encoded by let-23 gene, which is homologous to the vertebrate EGF receptor. The binding of LIN-3 protein and LET-23 receptor, trigger a series of intracellular events that determines whether the precursor cells will form the primary vulval precursor cell or secondary vulval cells. Mutant let-23 gene sends no signal and thus Pn.p cells cannot act, and vulva is not formed. Usually, P6.p cell, the closest cell to the anchor cell, receives the strongest signal initiated by LIN-3 binding to LET-23. Expression of the Vulvaless (Vul) gene (a mutant phenotype) in P6.p is activated by this signal, and then divides three times to produce vulva cells. The P5.p and P7.p, the two neighbouring cells, receives lower amount of signal, and divide asymmetrically to form additional vulva cells. Thereafter, a third level of cell-cell interaction occurs, in which the primary vulval cell P6.p sends a signal that activates lin-12 gene in P5.p and P7.p cells. This signal prevents these cells from adopting the division pattern of the primary cell. Thus, cells in which both Vul and lin-12 are active cannot become primary vulva cells. On the other hand, P3.p, P4.p, and P8.p cells do not receive any signal from the anchor cell, but the Multivulva (Muv) gene is expressed. Muv gene product represses the expression of Vul gene and they develop as skin cells. Thus three levels of cell-cell interactions are involved in the developmental pathway leading to vulva formation in the nematode C. elegans. CELL-CELL INTERACTION IN DEVELOPMENT Cell-cell interaction is an important phenomenon in the development of the embryo in eukaryotic organisms. Animals use a number of signalling pathway to regulate development after organogenesis. Signal networks establish anterior-posterior polarity and body axis, coordinate pattern formation, and direct the differentiation of tissues and organs. One of the widely studied cell-cell interaction is Notch signalling pathway, named after the Drosophila mutants that were used to identify components of this pathway. The Notch gene encodes a transmembrane signal receptor (Fig.11.9). The signal itself is a transmembrane protein called â€Å"Delta†, and encoded by the gene Delta. The Notch signal system works only between adjacent cells. First the â€Å"Delta† protein binds to the Notch receptor, which triggers cleaving of the cytoplasmic tail of the Notch protein and then moves to the nucleus where it binds to a protein encoded by the Su(H) (suppressor of Hairless) gene. Following this a set of genes becomes activated that controls a specific developmental pathway directing cell fate. One of the roles of the Notch signal system is to specify the fate of equivalent cells in a population. Thus action of Notch signalling system may send signal to two neighbouring cells that are developmentally equivalent, towards different developmental pathways. Four members of the Notch family (Notch 1 to Notch 4) have been identified in humans. Several human developmental disorders have been related to mutations in these genes. These include: alagille syndrome (AGS), spondylocostal dysostosis (SD), and lymphoblastic leukemia. STEM CELLS AND DEVELOPMENT Stem cells are undifferentiated cells that are capable to differentiate into different types of specialized cells. Stem cells are normally found in two main sources: in embryos which are at blastocyst stage of embryological development (embryonic stem cells), and in adult tissues (adult stem cells). These cells are generally characterized by their potential to differentiate into different cell types, for example muscle, blood, skin, bone etc. Human embryo that is in the blastocyst phase of development (4-5 days old) is the excellent source of embryonic stem cells. Formation of single cell zygote through fusion of male sperm with female’s egg is the beginning of sexual reproduction process. This is followed by a series of mitotic divisions in a single cell zygote which leads to the formation of a cell mass containing approximately 12-16 cells. This is known as blastocyst before it is implanted in uterus (4-6 days old). Blastocyst can be differentiated into an inner cell mass (embryoblast) and an outer cell mass (trophoblast). Trophoblast becomes the part of placenta and cells of embryoblast differentiate into all the structures of an adult organism. This embryoblast is the source of embryonic stem cells which are totipotent. During normal pregnancy, the blastocyst stage of embryo continues by the end of the tenth week of gestation. When embryonic stem cells are extracted from the blastocyst stage and placed onto a culture medium (a nutrient-rich broth) contained in culture vessels, they divide and replicate, but fail to differentiate. This happens, as necessary stimulation to differentiate (in the in vivo conditions) is lacking in the in-vitro conditions. However, they maintain their ability to differentiate into different type of cells in human body. Adult or somatic stem cells present throughout the body inside different type of tissues even after embryonic development. Tissues like, bone marrow, blood, blood vessels, brain, skeleton muscle, skin and the liver are good source of adult stem cells. These cells remain in resting state for years until activated by disease or tissue injury. Adult stem cells have property of division and self renewal which enables them to regenerate entire organ. Earlier it was believed that adult stem cells have the potential to differentiate only to the cell type of their originating tissue or organ, but according to some recent evidence they can differentiate to other cell types as well. Embryonic stem cells are easier to grow under in-vitro conditions as compared to adult stem cells. For culturing of stem cells, they are extracted from either adult cells or from dividing zygotes. Once isolated, they can be cultured in culture dishes containing culture broth under controlled conditions. The nutrient broth allows them to divide and replicate, but prohibits them from further specializing or differentiating. Once proliferation of stem cells starts successfully, they are subcultured on fresh medium in order to enhance the growth rate. The collection of healthy, dividing, and undifferentiated stem cells, after first subculture, is called as stem cell line. Once under control, these stem cell lines can be stimulated to differentiate into specialized cells, a process known as directed differentiation. Based on their potential to differentiate into other types of cells, stem cells are classified into the following categories. Totipotent: those cells which are able to differentiate into all possible cell types. Example, few cells which are obtained through initial divisions of the zygote. Pluripotent: those cells which are able differentiate into almost all cell types. Example, embryonic stem cells which are derived from the endodermal, mesodermal, and ectodermal layers of blastocyst. Multipotent: those cells which are able to differentiate into closely related family of cells. Example, hematopoietic stem cells that has the potential to form red/white blood cells and platelets. Oligopotent: those cells which are able to differentiate into a few cells. Example, lymphoid and myeloid stem cells. Unipotent: those cells which are able to produce cells of their own type, but have the property of self-renewal. Example, adult mouse stem cell. For identification of stem cells, it is important to note that they are undifferentiated and capable of self-renewal. These two parameters are normally checked through laboratory tests for identification of stem cells. Bone marrow or hematopoietic stem cells (HSC) are tested by transplanting these cells to an individual from which HSCs are removed. The production of new blood and immune cells in that individual indicates the self renewal potency of stem cells. Colonogenic assay (a laboratory procedure) is also used to test the potency of stem cells. Routine examination of chromosomal can also be done to check whether the cells are healthy and undifferentiated. Sometime spontaneous or induced differentiation of embryonic stem cells under cell culture conditions indicates their pluripotent nature. Other tests include administration of stem cells into an immunosupressed mouse and observe it for the formation of a teratoma, which is a benign tumour containing a mixture of differentiated cells. Applications of Stem Cells It is important to note that every cell and tissue in the body of an individual is develop and differentiate from initial few stem cells which form during early stages of embryological development. Therefore, embryonic stem cell can be induced to differentiate into any other type of cells. Due to this regeneration potential, stem cells have been used by researchers to regenerate damaged tissues and organs under the right conditions. Usually damaged organs are replaced by healthy organs donated by someone. But the demand far exceeds the supply of organs. Particular type of tissue or organ could potentially be developed from stem cells, if directed to differentiate in a certain way. For example, stem cells that present just beneath the skin tissue have been used to regenerate new skin tissue and then grafted on to burn victims successfully. Another potential application is replacement of cells and tissue for treatment of brain disease like Parkinson’s and Alzheimer’s. If the damaged tissue can be replenished by specialized tissue derived from stem cells such diseases can be treated for recovery. In the near future it may be possible to transplant healthy heart cells developed in a laboratory from stem cells into the patients with heart disease, thereby repopulating the heart with healthy tissue. Similarly it may be possible to replace damaged pancreatic cells by insulin producing cells derived from stem cell, to treat type l diabetic patients. For the treatment of diseases like leukemia, sickle cell anemia and other immunodeficiencies, adult hematopoietic stem cells found in bone marrow and blood have been used. All type of blood cells (erythrocytes as well as leukocytes) can be developed from HSC. However it is difficult to isolate hematopoietic stem cells from the bone marrow. Alternatively, hematopoietic cells are also found in the umbilical cord and placenta, from which they can be isolated easily. Realizing its potential use, umbilical cord blood banks have been established to store these powerful cells for their future use. Therapeutic cloning or somatic cell nuclear transfer (SCNT) technique involves replacement of genetic material from a somatic cell (say from skin cell) into an unfertilized egg cell in order to develop patient specific stem cells. In this procedure, since sperms are not involved fertilization does not occur. Foetus is also not involved because the groups of cells from which the stem cells are obtained are not implanted in the uterus. Stem cells which are developed through SCNT technique have more potential for therapeutic applications. The chances of rejection by patient’s body are less because their genetic makeup is identical to patient’s genetic makeup. Through SCNT, disease specific cell lines can be developed which are used for in-vitro studies to understand the mechanism of disease development and mode of action of certain drugs which may be used to treat these diseases. Stem cell research is also useful for understanding development of human after formation of fertilized zygote. Undifferentiated stem cells eventually differentiate partly because of turning on or off of particular gene(s). Thus research on stem cell may help to clarify the role of specific genes that play in determining how specialized cells and tissues are formed. Stem cell research is also being pursued to develop new drugs. Healthy human tissues which are developed through stem cells can be used to evaluate the effect of new drug rather than using human volunteers. Table.11.1. Segmentation gene loci in Drosophila â€Å"Gap† genes â€Å"Pair-role† genes â€Å"Segment polarity† genes Giant Ever skipped Armadillo Huckebein Fushi tarazu Cubitis interruptus Hunchback Hairy Disheveled Kruppel Odd paired Engrailed Knirps Odd skipped Fused Tailless Runt Gooseberry Sloppy paired Hedgehog Naked Paired Patched Wingless Figure Captions Fig. 11.1. Early stages of embryonic development in Drosophila. A cascade of gene activation sets up theDrosophilabody plan. Thematernal-effect genes, named as bicoid and nanos, are active during oogenesis. The products of these genes are found in the egg at the time of fertilization, and form morphogen gradients. These proteins function as transcription factors that regulate the expression of gap genes. The gap genes are responsible for the differentiation of anterior-posterior axis on embryo along its length. Proteins which are encoded by gap genes also function as transcription factors and regulate the expression of the pair-rule genes. Thepair-rule genesare responsible for differentiation of pairs of segments on embryo. Transcription factors which are encoded by pair-rule genes regulate the expression of thesegment polarity genes. The expression of segment polarity genes leads the development of anterior/posterior axis of each segment. The gap genes, pair-rule genes, and segment polarity genes are collectively involved in segment patterning hence they are known as segmentation genes. Fig. 11.2. The hierarchy of genes involved in establishing the segmented body plan in Drosophila. Gene products from the maternal genes regulate the expression of the first three groups of zygotic genes (gap, pair-rule, and segment polarity, collectively called the segmentation genes), which in turn control the expression of the homeotic genes. Fig. 11.3. Progressive restriction of cell fate during development in Drosophila. Fig. 11.4. Overlapping of regions containing two different gene products can generate new patterns of gene expression. Transcription factors A and B are present in overlapping region 3, of expression. If both the transcription factors must bind to the promoter of a target gene to trigger expression, the gene will be active only in cells containing both factors (most likely in the zone of overlap). There shall be no transcription in individually in the region 1 and 2. Fig. 11.5. Cell arrangement in the floral meristem. (a) The four concentric rings, or whorls, labeled 1-4, influenced by genes A, B, and C in the manner shown, give rise to the sepals, petals, stamens and carpels, respectively, (b) The arrangement of these organs in the mature flower. Fig. 11.6. A truncated cell lineage chart for C. elegans, showing early divisions and the tissues and organs that eventually result. Each vertical line represents a cell division, and horizontal lines connect the two cells produced. Fig. 11.7. An adult Caenorhabditis elegans hermaphrodite. Fig. 11.8. Cell lineage determination in C. elegans vulva formation. Fig. 11.9. Components of the Notch signalling pathway in Drosophila.