Arc Welding Concept and Process

Arc Welding Concept and Process Arc welding is a process of the fusion welding processes which contains:- 1 Arc welding processes (non consumable electrodes) Gas tungsten arc welding Plasma arc welding Atomic hydrogen welding 2 Arc welding processes (consumable electrodes) Shielded metal arc welding Submerged arc welding Gas metal arc welding Flux cored arc welding Electro gas welding Electro slag welding 3 Electron beam welding 4 Laser beam welding The main concept of fusion welding is the partial melting and fusion of the joint between two members and a filler metals may be used. In the arc welding process, the heat required is obtained from electrical energy. An arc is produced between the tip of the electrode and work piece to be welded, by using an AC or a DC power supply. Shield metal arc welding (SMAW) is one of the oldest, simplest, and most versatile joining processes. About 50% of all industrial and maintenance welding currently is performed by this process. The electric arc is generated by touching the tip of a coated electrode against the work piece and withdrawing it quickly to a distance sufficient to maintain the arc. The heat generated melts a portion of the electrode tip, its coating and the base metal in the immediate arc area and this mixture forms the weld when it solidifies. Classification Of Arc Welding The arc welding classified into many types used in the industrial field each one have advantages and defects different from the other type, So that the user select the required type according to the requirements and the economy aspects. In the below figure we show for the classification of arc welding which appear in the industrial (3.1) Chart key SMAW: shield metal arc welding SAW: submerged arc welding TIG: tungsten inert gas arc welding MIG: metal inert gas welding PAW: plasma arc welding ESW: electro slag welding The above chart list for the types of the arc welding which used in the industrial fields. Advantages of arc welding There are some characteristic for the arc welding rather than the another methods to joining metals which it represent the advantages of the arc welding listed as below Strong and tight joining Cost effectiveness ( arc welding have low capital and running costs) Simplicity of welded structure design Figure 3.2: arc welding usage in the industry (http://64.78.42.182/sweethaven/BldgConst/Welding/lessonmain.asp?lesNum=4modNum=1) Principals And Definition Shield metal arc welding (SMAW) consider as process in which coalescence of metal produced by the heat which generated from the electric arc that it maintained between the tip of the consumable electrode and the base metal in the welding region. The next figures show the circuit used in the shield metal arc welding Power Supply The shield arc welding power source provides constant current (cc) it may be alternative current (Ac) or direct current (DC) depending on the electrode being used, but the best welding usually used the direct current (DC) as power supply for the circuit. The amount of power required to welding process calculated from the relation (P= IV) Where I represent the current V represent the voltages In the selection process for the power supply we notice that the voltage equal to constant value so that the current is the main parameters in the selection process which discussed in the next section Current Setting The amount of current needed to melt the work piece and the electrode tip depends on several factors as Type and position of the joint Work piece type and its thickness Electrode type and its diameter In facts most of welder select the current depending on the diameter of the used electrode which it measured from the inner section without the coated diameter as showing in the below figure: A basic guide of arc welding electrodes by Bruce Bauerlein http://www.metalwebnews.com/howto/weldrod.html http://www.weldershop.info/282/types-of-welding-electrodes/ Electrode The electrode used in (SMAW) process consist from metal rod coated in metal mixture called flux which gives off gases as it decomposes to prevent weld contamination , introduces deoxidizer to purify the weld , causes weld- protection slag and provides alloying elements to improve the weld quality. there are three types from the electrode used in (SMAW) process which discussed below. Fast fill electrode: this type from electrode designed to melt quickly so that the welding speed be maximized. This type used when we weld in the normal case in vertical welding so we can weld with high speed so we use this electrode type. Fast freeze electrode: this type from electrode designed to solidify quickly making welding in a variety of positions possible by preventing the weld pool from shifting. Intermediates electrodes : the commonly used type and it intermediate in two case melting and in freezing but if we weld with high speed with using this type we get poor quality so that this type is not suitable in case of high speed. The American welding society established system that used to assign electrodes by using four or five digital number. Covered electrodes made of mild steel or low alloy steel carry the symbol of (E) followed by their number. the first two . The first two or three digits of the number specify the tensile strength of the weld metal, in thousand pounds per square inch . The penultimate digit generally identifies the welding positions permissible with the electrode, typically using the values 1 (normally fast-freeze electrodes, implying all position welding) and 2 (normally fast-fill electrodes, implying horizontal welding only). The welding current and type of electrode covering are specified by the last two digits together. Example for electrode serial number E7018 E indicates electrode 70 indicates 70,000 psi tensile strength 1 indicates use for welding in all positions 8 indicates low hydrogen 2. Cables: there are two cables work cable which connected the base metal and the electrode cable which connected to the electrode one of them represent positive and the other represent the negative side this according to the polarity of the welding process Welding Trouble Shooting This section discuss to the trouble shooting may faced it during the welding speed as 1-Porosity: small cavities or holes resulting from gas pockets in weld metal. www.miller.com.pdf The porosity in welding it may be caused by the dirty on work piece and the corrective action to face it by Remove all grease, oil, moisture, rust, paint, coatings, slag, and dirt from work surface before welding. Excessive Spatter: scattering of molten metal particles that cool to solid form near weld bead as shown in the below figure. www.miller.com.pdf The main causes to excessive spatter is the current too high for electrode and it avoid by decrease current or select larger electrode. 3- Distortion: contraction of weld metal during welding that forces base metal to move. www.miller.com.pdf Distortion in the welding appear as result to excessive heat input. And there is many ways to solve this problem as Use restraint (clamp) to hold base metal in position Make tack welds along joint before starting welding operation. Select lower amperage for electrode. Increase travel speed Lack of Penetration: shallow fusion between weld metal and base metal. www.miller.com.pdf The lack of penetration appears as result for many causes as showing below: Possible causes Corrective action Improper joint preparation Material too thick. Joint preparation and design must provide access to bottom of groove. Improper weld technique. 1-Keep arc on leading edge of weld puddle. 2-Reduce travel speed. Insufficient heat input. Increase amperage. Select larger electrode and increase amperage Advantages Of Shield Metal Arc Welding The shield arc welding have main further that represent the advantages as below Strong and tight joining rather than the other methods Cost effectiveness (have low capital and running cost) The arc welding Simplicity of welded structures design May be mechanized and automated or manual in some duty Disadvantages Of Arc Welding The using of the shield metal arc welding lead to some defects as Internal stresses, distortion and change for the microstructure in the weld region Have harmful effects as radiation and fumes Application Of The Shield Arc Welding The arc welding it can be used in many applications as: Buildings and bridges structures Automotive, ship and aircraft constructions Pipe lines Tanks and vessels (2.2) Polarity: To introduce what the polarity means and the different type of the polarity, first of all the project will show what is the difference between AC and DC? AC And DC Current What Is The AC Current? It means alternating current. In this current the electric charge flow periodically reverses direction. The electric charge in this case will move for instance backward then it will reverse the direction again to move forward, then backward then forward over and over again. The waveform for alternating current is a sine wave. But sometimes in certain applications the waveform differs like square wave or triangular wave. Dc Current What Is The DC Current? It means direct current because the electric charge in direct current moves in a constant direction, and that is the difference between DC and AC. The DC could be produced by such sources like thermocouples, batteries and solar cells. We can use a rectifier which is a current-switching arrangement to obtain direct current from an alternating current. The concept of rectifier is containing electromechanical elements or electronic elements which allow current to flow only in one direction. AC And DC Welding Machines: The welder or welding machine is the power source that we used in arc welding. There are three basic types of weldingmachines used now which are rectifiers, motor- generators and transformers Motor generator welding machines (direct current welding machines): The motor generator could be powered by diesel, electrical or gasoline motor. We can use the gasoline and diesel motors in places where the electricity is not available or hard to reach it like deserts. With these machines we could generate either direct or alternating current. There are new and old machine types of these machines, the older type require reversing the cable connections in order to change the polarity. But in the new machines you can change the polarity from welding in the direct current mode to alternating current mode by turning a switch. Theadvantages of a (dc) welding generator: The main advantage of a direct-current (dc) welding generator is that you can weld with either reverse or straight polarity. Almost we can weld all ferrous and non-ferrous metals. We can use DC in practically all welding operations so we can consider that DC is most universal in application. The output of generators like rectifier and transformer a sets is not affected by normal variations in power line voltage. Diesel driven generators form self-contained units. Disadvantages of a (dc) welding generator: The initial cost is high The machine operation is noisy The maintenance cost is high AC transformers welding machines: The static-transformer type is the arc welding machines that we used in alternating current. As shown in the figure 2.18 The advantages of these types ofmachines are lightest, smallest and least expensive welders made. We can use 200, 300, and 400 ampere ratings for manual operation in industrialapplications. But in light industrial, job/shop and garage welding we could use machines with a 150-ampere rating. These types of transforms equipped with arc- stabilizing capacitors. The advantage of a (AC) transformer welding machine: The main advantage of (AC) transformer welding machine is the freedom from arc blow. The arc blow causes the arc to wander while you are using large coated electrodes or welding in corners on heavy metal. The arc blow often occurs when welding with direct current machines. Polarity What is the polarity? Polarity is the direction of the current flow in a circuit. There are two types of polarity reverse polarity and straight polarity. In the straight polarity the work piece is positive and the electrode is negative. The electrons move from the electrode to the work piece. In the reverse polarity the work- piece negative and the electrode is positive. The electrons move from the work piece to the electrode ac and dc current was briefly covered. The effect of polarity: The polarity affects the amount of heat which is going to the base metal. You can direct the amount of heat to where it is needed as per the application you working in by changing the polarity. If you want to direct the majority of heat toward the work piece, you must use straight polarity. That type of polarity being used in some welding situations when it is desirable to have more heat on the work piece because of its size to melt the base metal than the electrode. We can use straight polarity for all mild-steel, bare, or lightly coated electrodes. If you want to concentrate the heat on the electrode, you can use reverse polarity because in this type less heat is concentrated at the work piece which allow filler metal to cool faster, giving it greater holding power because of this reverse polarity is being used when you are making vertical and overhead welds. Reverse polarity could be used in the welding of nonferrous metals such as bronze, aluminum and nickel. Heat Affected Zone Heat affected zone definition. The heat affected zone (HAZ) represented by the area of base material subjected to the high heat in order to achieve the welding process. The area which subjected to change in its microstructure and mechanical properties. SMAW process give a highly heat concentration in specified region called (fusion zone), produced in the region of heat affected zone. To calculated the amount of heat in the HAZ the following formula used. Q =60 VI / 1000S Where Q = heat input (kj/mm), V = voltage (V), I = current (A), and S= welding speed (mm/ min). (2.10) The molten occur in the fusion region not in the heat affected zone. So that the HAZ heated to a high enough temperature for sufficient period that grain growth occurred. Heat affected zone is that location of the base metal which in it the mechanical properties and the microstructure have been affected by the heat of welding process. The heat affected zone is subjected to a complex thermal cycle (sudden heating followed by rapid cooling) in which all temperatures from the melting range of the metal down to much lower temperatures are involved and HAZ therefore consists of a series of graded structures ringing the weld bead. HAZ usually contains a variety of microstructures different from the remaining part from the base metal. The width of HAZ varies according to the welding process and technique; in arc welds it extends only a few mm from the fusion boundary, The HAZ in most metal welding process of normal structure welded in one run with coated electrodes that to classify it to four basic region. Classification And Designation The classification of electrodes is done by one of the three following categories: 1 Strength of the deposited weld metal 2 Current (ac or dc) 3 Types of coating The identification of electrodes is by numbers and letters as shown in the next table. Typical coated electrode dimensions are in the range of 150 to 460 mm (6 to 18 in.) in length, and 1.5 to 8 mm (1/16 to 5/16) in diameter. Specifications for electrodes and filler metals (including dimensional tolerances, quality control procedures, and processes) are published by the American welding society (AWS) and the American national standards institute (ANSI). Some specifications appear in the aerospace materials specifications (AMS) by the society of automotive engineers (SAE). Electrodes are sold by weight and are available in a wide variety of sizes and specifications. Electrodes Types And Choices When the choice of a suitable electrode is needed, many considerations are taken such as Quality of weld Penetration Used current whether AC or DC Crack resistant

Literary Analysis of Bartleby the Scrivener Essay

Bartleby the Scrivener could be described as a story about getting rid of its title character, about the narrator’s attempt to get rid of Bartleby, and Bartleby’s tenacious capacity to be always there. It is the story of an unnamed lawyer and his employee, Bartleby, a copyist of law documents. Confronted not only with Bartleby’s refusal to do work (first to â€Å"read† copies against the original, then to copy altogether), but also with the contagious nature of the particular words of his refusal (Bartleby’s peculiar â€Å"I would prefer not to†), the narrator concludes that, before Bartleby â€Å"turns the tongues† any further of those with whom he comes into contact, he â€Å"must get rid of† Bartleby. At the same time Bartleby feels â€Å"mobbed in his privacy† (27) when the other office workers crowd him behind his screen, they in turn are invaded by his idiosyncrasy – his private idiom â€Å"prefer. † Bartleby’s presence breaks down the clear distinctions between public and private, professional and domestic, between â€Å"privacy† and â€Å"the mob. † By pinpointing Bartleby as the â€Å"cause† of infectious language (language â€Å"turned† bad), the narrator wants to stop the course of a process (the â€Å"turning of tongues†) already in progress. But getting rid of Bartleby is as tricky as getting rid of a chronic condition; the narrator emphasizes a phrase which appears textually in italics: â€Å"he was always there† (20). Bartleby is, as the narrator calls him, a â€Å"nuisance† (40), an â€Å"intolerable incubus. † As a character in the story with a body, he moves very little, but the few words he speaks break out at unexpected moments in the office. Every attempt the narrator makes to control the passive Bartleby and his infectious language fails hilariously (Schehr 97). The narrator experiences a curious tension between the impossible imperative (on the level of the story) to get rid of the subject, and the impossibility (on the level of the narration) to write his complete biography (Bartleby’s â€Å"history†). Thus, Bartleby is also a fable about writing history or biography. In attempting to write what he thinks of as Bartleby’s biography, the narrator merely misnames his writing project, or he emphasizes it from the wrong point of view. In search of Bartleby’s origins, the narrator does not simply narrate (as he thinks) the history of Bartleby the Scrivener; he relates rather the story of his own anxiety vis-a-vis Bartleby. In particular, he relates his anxiety over the scrivener’s silence – and modes of breaking that silence; for we could say that, rather than speaking very little or in particular ways, Bartleby has particular ways of occasionally breaking silence. It is this violence in speech, this unexpected eruption, which the narrator fears. The narrator, whose acquaintances describe him as an â€Å"eminently safe man,† who likes nothing better than the â€Å"cool tranquility of a snug retreat† (4), is thrown decidedly off kilter when faced with what he terms Bartleby’s â€Å"passive resistance† (17). Bartleby’s weapon is his total indifference to truth, whereas the narrator seeks a second opinion on truth from the other office mates. Bartleby could be seen as the one solid block around which the narrator writes his own story about truth rather than the truth about the Bartleby story. Bartleby’s passive resistance actually generates the story — confronted with it, the narrator creates theories (his doctrine of assumptions, for instance), carries on debates with himself, and seeks the counsel of others — all with the opaque Bartleby as the core. In reconstructing Bartleby’s story, the narrator follows an implicit logic which he never directly states. It is the logic of cause and effect. (He is not deliberately hiding this logic, but because he takes its validity for granted, he never comments on it critically. ) Believing in the possibility of finding a specific, locatable, and nameable cause to Bartleby’s condition (as he is able to do with the other office workers, Nippers and Turkey, whose moods vary according to their diets and the time of day), the narrator thinks that by eradicating the cause of the problem, he can alter the effects, the effects of Bartleby’s speaking condition in the office space. McCall follows the same logic as the narrator in seeking causes of Bartleby’s behavior. He mentions remark that when the narrator asks Bartleby to run an errand for him at the post office, â€Å"that is probably the last place, if the rumor is correct, that Bartleby would ever want to go. † (McCall 129). The narrator never considers that his line of reasoning might be faulty — that Bartleby’s condition may not be linked to a specific, locatable, nameable cause. We as readers may be placed in the same position as the narrator in that we never know either the origin of Bartleby’s condition; we witness primarily its effects, or symptoms, in the story. These symptoms reside not only in Bartleby as individual character, but in the very way the narrator tells the story about that character. Rather than speaking about the cause of Bartleby’s condition, one could more aptly speak about the ways in which its effects are spread to other characters within the text. When the narrator impatiently summons Bartleby to join and help the others in the scenario of group reading, Bartleby responds, â€Å"I would prefer not to† (14). Hearing this response the narrator turns â€Å"into a pillar of salt† (14). (Faced with Bartleby’s responses and sheer presence, the narrator oftentimes evokes images of his losing, then waking to, consciousness. ) When he recovers his senses, he tries to reason with Bartleby, who in the meantime has retreated behind his screen. The narrator says: â€Å"These are your own copies we are about to examine. It is labor saving to you, because one examination will answer for your four papers. It is common usage. Every copyist is bound to help examine his copy. Is it not so? Will you not speak? Answer! † (15) The narrator is exasperated when Bartleby does not respond immediately to the logic behind his work ethic. â€Å"These are your own copies we are about to examine. It is labor saving to you. † Examining or reading copy is a money saving activity, from which every member of the office profits (four documents for the price of one reading! ). â€Å"Every copyist is bound to help examine his copy. † To the contract the lawyer emphatically demands from his employee, a bond based on an exchange of reading, Bartleby replies three times, gently, â€Å"in a flutelike tone,† â€Å"I (would) prefer not to† (15). By refusing to read copy, Bartleby refuses to consent to the economy of the office. It is perhaps only to another type of reading, one not based on a system of exchange and profit, which Bartleby consents. Although the narrator says he has never seen Bartleby reading — â€Å"not even a newspaper† (24) — he does often notice him staring outside the window of the office onto a brick wall. Staring at the dead brick wall (in what the narrator calls Bartleby’s â€Å"dead-wall reveries†) may be Bartleby’s only form of reading, taking the place of the economy-based reading demanded of him in the process of verifying copies. About halfway through the story, the lawyer/narrator visits his office on a Sunday morning and, discovering a blanket, soap and towel, a few crumbs of ginger nuts and a morsel of cheese, deduces that the scrivener never leaves the office. Realizing the full impact of Bartleby’s condition, he states, What I saw that morning persuaded me that the scrivener was the victim of innate and incurable disorder. (25) The narrator clearly locates the disorder in Bartleby. Seeing himself in the role of diagnostician and healer, he himself is faced with the â€Å"hopelessness of remedying excessive and organic ill† (24). The narrator’s concern about an individual medical cure should more aptly be a concern about an obsessively private rhetorical debate or a dangerously idiomatic group contagion (Perry 409). Despite his assumption that Bartleby is incurable, or perhaps precisely because he can effect no cure, the narrator beleaguers himself throughout the story with questions or commands to do something about Bartleby (McCall 9). If the private man’s disorder can be passed on to another (one) person, what happens when the condition is let loose out of close quarantine into the public space of the office? Bartleby walks a precarious tightrope between comedy and tragedy (Inge 25). The tragic dimension often resides in the narrator’s turning inward on himself (a sort of tragic compression), then putting himself on trial, an interior moment of accusation which eventually results in the collapse of the narrative in a single sigh or exclamation (â€Å"Ah, Bartleby! Ah, humanity! † 46). The comic effects are often related to the authoritarian attempt (and failure) to contain the spread of idiom as contagion (Perry 412). If Bartleby has been a figure for tragedy in the lone meditation of the narrator, he becomes a figure for comedy in his contact with his office mates Nippers and Turkey. The more the narrator tries to regulate the contact between the three, the more hilarious — and significantly out of control — is Bartleby’s influence. The effort to contain or control tends actually to promote the epidemic proportions of the narrative. It is the narrator himself who uses a vocabulary of contagion in relation to Bartleby. He says he has had â€Å"more than ordinary contact† (3) with other scriveners he has known. Bartleby exceeds this already extraordinary contact – he has been touched by â€Å"handling† dead letters (Schehr 99). Some critics reproduce the narrator’s language of contagion in talking about Bartleby. McCall, in his study on The Silence of Bartleby, describes â€Å"our† response, the collective readers’ response, to reading the tale: As we go through the story, we watch with a certain delight how Bartleby is â€Å"catching. † We root for the spread of the bug. (145) In a somewhat less delighted vein, Borges says, â€Å"Bartleby’s frank nihilism contaminates his companions and even the stolid man who tells Bartleby’s story. † (Borges 8) In the office scenes where the employees and boss come inevitably together, the â€Å"bug† word is Bartleby’s â€Å"prefer. † Nippers uses it mockingly against the narrator as a transitive action verb when he overhears Bartleby’s words of refusal to the narrator’s plea â€Å"to be a little reasonable. † Bartleby echoes, â€Å"At present I would prefer not to be a little reasonable† (26). If Nippers is suffering from his own peculiar and chronic condition of indigestion, he takes on the symptoms of Bartleby’s condition when he exclaims to the narrator, Prefer not, eh?†¦ – I’d prefer him, if I were you sir, I’d prefer him; I’d give him preferences, the stubborn mule! What is it, sir, pray, that he prefers not to do now? (26) Whereas later in the story the narrator totally loses his critical skill to â€Å"catch† himself in his speech, in this exchange he is still able to articulate the effect Bartleby’s â€Å"word† is having on him. He notes anxiously, Somehow, of late, I had got into the way of involuntarily using the word ‘prefer’ upon all sorts of not exactly suitable occasions. (27) It is this qualifier â€Å"not exactly† which is of particular interest. Bartleby’s use of words is â€Å"not exactly† wrong. â€Å"Prefer† is so insidious because it is only slightly askew, dislocated, idiosyncratic. As McCall accurately notes about the power of Bartleby’s â€Å"I prefer not to,† â€Å"one must hear, in the little silence that follows it, how the line delivers two contradictory meanings, obstinacy and politeness. â€Å"(152) The line calls just enough attention to itself so as to attract others to its â€Å"profoundly mixed message† (â€Å"its perfect yes and no†) in an imitative way (McCall 152). â€Å"Prefer† is as inobtrusive, as contagious, and as revolutionary as a sneeze. The narrator lets it out of his mouth involuntarily. When Turkey enters the scene and uses the bug word without realizing it (without Nippers’ italicized parody or the narrator’s critical comments), the narrator says to him, in a â€Å"slightly excited† tone, â€Å"So you have got the word, too† (27). In this pivotal sentence, the verb â€Å"get† implies â€Å"to receive† (as in â€Å"to receive a word or message†), but more strikingly for our discussion here, it implies the verb â€Å"to catch† – one â€Å"catches† the word as one would â€Å"catch† a cold. The narrator attempts to monitor the contagion by naming the bug and pointing it out to the others. But the word mocks everyone’s will to control it â€Å"prefer† pops up six times in the next half a page — four times unconsciously in the speech of one of the employees, and twice consciously (modified by â€Å"word†) in the narration of the lawyer. Bartleby could be described as a story of the intimacy – or anxiety – a lawyer feels for the law-copyist he employs. The narrator arranges a screen in the corner of his office behind which Bartleby may work. Pleased with the arrangement of placing Bartleby behind the screen in near proximity to his own desk, the narrator states, â€Å"Thus, in a manner, privacy and society were conjoined† (12). The narrator idealizes the possibility of a perfect harmony between privacy and community in the work environment, but it is precisely the conflict between these two spatial â€Å"conditions† which generates the story, defining not only Bartleby’s â€Å"idiocy,† but the narrator’s as well. The narrator most characteristically encounters Bartleby â€Å"emerging from his retreat† (13) or â€Å"retiring into his hermitage† (26). The screen isolates Bartleby from the view of the narrator, but not from his voice. Works Cited Borges, Jorge Luis. â€Å"Prologue to Herman Melville’s ‘Bartleby† in Herman Melville’s Billy Budd, â€Å"Benito Cereno,† â€Å"Bartleby the Scrivener,† and Other Tales, ed. Harold Bloom. New York: Chelsea House Publishers, 1987 Inge, Thomas M. , ed. Bartleby the Inscrutable. Hamden, CT: Archon Books, 1979. McCall, Dan. The Silence of Bartleby. Ithaca: Cornell University Press, 1989. Melville, Herman. â€Å"Billy Budd† and Other Stories. New York: Penguin Books, 1986. Perry, Dennis R. â€Å"‘Ah, Humanity’: Compulsion Neuroses in Melville’s Bartleby. † Studies in Short Fiction 23. 4 (fall 1987): 407-415. Schehr, Lawrence R. â€Å"Dead Letters: Theories of Writing in Bartleby the Scrivener† Enclitic vii. l (spring 1983): 96-103.

Identity Thesis Essay

Over the course of history, different theories have been formulated to help explain the complex relationship between the mind and the body. One of the theories elucidating the mind-body relation is dualism—the view that mental states are independent from physical states. Mental states are ones of thinking, feeling, and believing whereas physical states are those outlined by physical and biological sciences. In contrast to dualism, physicalism insists that mental states are somehow physical states. The most straightforward version of physicalism is the identity thesis—the theory that every type of mental state is identical to some type of physical state (Reasons and Responsibility, 285-286). Dualists and physicalists have disputed over the validity of the identity thesis; dualists denying its claim and physicalists defending it. The biggest problem facing physicalists and the identity thesis is the concept of qualia, the phenomenal quality of a mental state (Reasons and Responsibility, 281). Philosopher Frank Jackson offers what he calls the â€Å"Knowledge Argument† for qualia. Jackson’s knowledge argument presents that nonphysical facts can be devised from facts about phenomenal quality. Through the concept of qualia, Jackson’s knowledge argument shows that the identity thesis is false. The identity thesis holds that mental events are simply identical with brain processes—identical in the same manner that sounds are identical with density waves in the air. The thesis bases on the idea that mental states of thought, sensation, and awareness are alike those of physical states (such as those of the brain and central nervous system). An example of identity thesis is that lightning and an electric charge are two of the same thing. In other words, lightning is an electric charge. An advocate of the identity thesis is materialist Peter Carruthers. Carruthers argues that everything (including mental states) exists through physical causes. Carruthers’ argument for the identity thesis can be summarized from the beliefs that some conscious states and events are casually necessary for the occurrence of some physical ones, and that there will be no need to advert to anything other than physical-physical causality in a completed neuro-physiological science. Thus, some conscious states and events are identical with physical brain states and events (Reason and Responsibility, 301-302). However, the concept of qualia refutes the idea of physicalism, and is the foundation of Jackson’s knowledge argument against identity thesis. As a believer of dualism, Jackson uses the concept of qualia to support that the mind and matter are distinct and independent substances capable of existing without the other. Qualia are the subjective, felt qualities of experiences. For example, one may know all the physical properties of the color red and the physics behind why some things are red; however it is qualia that allows one to experience what it is like to actually see red. Jackson constructs his knowledge argument around the ideas of dualism and qualia. To further illustrate Jackson’s argument for qualia (and dualism), the case of Fred and his unique color vision will be presented (Reasons and Responsibility, 298-299). For some reason, Fred has the ability to see two colors where others only see one. His retina is capable of distinguishing between two wavelengths of red in which others familiarizes with only one. He tries to explain the difference between the two reds. However he fails in doing so because others do not comprehend the difference. Therefore it is concluded that Fred can visually see one more color than everyone else. Despite having all the physical information about Fred and his special trait, one cannot know what it actually feels like to see two different types of red. Thus, Jackson believes that the physicalist left something out in the theory of physicalism—the qualia or what it feels like to actually experience something. Consequently, quale explains how dualism is valid and physicalism is incomplete. The existence of knowledge through qualia (mental state) and that of physical facts (physical state) demonstrates the idea of dualism—the view that two fundamental concepts exist. Jackson’s knowledge argument derives mainly from his thought experiment of Mary; the brilliant scientist who has spent her life confined within a black-and-white room and has never seen colors. Mary learns all the physical facts relevant to the mind. She becomes an expert on the neurophysiology of vision and knows all there is to know about color. When Mary is released from her room, she experiences color for the first time. One would think intuitively that her color experiences provide her with knowledge she previously lacked, and that what she learns includes certain facts about what color experiences are like. The facts she learns upon her release cannot be physical facts because she already knew all physical facts before leaving the room. Therefore, the new knowledge comes from the concept of qualia, which indicates that not all facts are physical facts (Reason and Responsibility, 298-299). Thus physicalism is false. Jackson reaches his conclusion that the identity thesis is false by proving that mental states are not physical states. According to the identity thesis, states and processes of the mind are identical to states and processes of the brain. The concept of qualia refutes the validity of the identity thesis by presenting subjective forms of experiences. The knowledge acquired from subjective forms of experiences differs from those of physical knowledge about experiences. Since physicalism requires that all aspects of knowledge are the same, physicalism cannot be sound. Thus the identity thesis must be false. The cases of Fred and Mary show that physicalism doesn’t amount to all knowledge. The summation of Jackson’s knowledge argument can be illustrated by the following: before Mary leaves the room, she knows all the physical facts about color experiences. When Mary leaves the room, she learns new facts about color experiences—facts about what it’s like to see in color. Therefore, there are nonphysical facts about color experiences. Furthermore, the identity thesis is false because Jackson’s knowledge argument reveals that there is something about the experience of color (in Mary’s case) that cannot be captured by the physicalist view. So, physicalism is incomplete. Physicalism lacks the phenomenal quality of the mental state—the ability to experience something regardless of physical knowledge. Qualia and the mental experience can never be achieved from the premises of physicalism and the identity thesis. Thus, the phenomenal quality of experiences cannot be accounted for through physical properties of the brain. In conclusion, the identity thesis is false because nonphysical properties, like phenomenal properties, exist.

French Vocabulary Lesson Hobbies, Sports, Games

Many people have a favorite pastime or two, including sports, games, or other hobbies. Since you are studying French, learn how to talk about your favorites as you expand your vocabulary in the realm of fun activities.  When you have completed this lesson, continue to expand your sports vocabulary  and have even more fun. Hobby, Sports, and Games The specific translations for the terms hobby, sports, and games are as follows: Hobby le passe-temps favorisSports   des sportsGames    jeux Expand your French vocabulary related to these terms by perusing the tables below. In the tables, the word is presented first in English in the left column to make it easier to find the term you need. The French translation for each term is listed in the right column. Many of the French words are linked to audio files. Simply click on the link to listen to the correct pronunciation of the term. Sports, Games and To Play Many of the terms in this section are similar to the English words with which you are already familiar. To speak about the action of playing these sports, use the verb   jouer  au  (to play)  before the name of the sport, as in: To play chess   jouer  aux  Ãƒ ©checsTo play basketball    jouer  au basket English French basketball le basket football le football amà ©ricain soccer le football or le foot hockey le hockey tennis le tennis chess les à ©checs Hobbies and To Make/Do This next set of activities includes sports, hobbies, and other things you might do in your free time. The one thing that they have in common is that they use the verb  faire  (to make or to do). In most cases, you will combine the verb  faire de with the noun, as in: To garden  Ã‚  faire du  jardinageTo ride a bike   faire du  và ©lo However, in some instances, you have the option of using a form of the noun itself when you speak about performing that activity. Those special cases are noted in the fourth column of the chart. For instance, you can say faire  la cuisine  or  cuisiner,  which both mean to cook. English French Noun Use with Or use biking le cyclisme, le và ©lo faire de cooking la cuisine faire cuisiner gardening le jardinage faire de jardiner hiking la randonnà ©e faire de hunting la chasse faire chasser jogging le jogging faire de reading la lecture faire lire sailing la voile faire skiing le ski faire de skier swimming la natation faire de nager television (TV) la tà ©là ©vision (la tà ©là ©) regarder wrestling la lutte faire de lutter Other Hobbies and Verbs The following activities use verbs other than  jouer  au  and  faire. The same rules apply to this set as has been discussed previously, as in this phrase: To go fishing -  aller  Ãƒ  Ã‚  pà ªcher  or pà ªcher English French Noun Use with Or use dancing la danse danser fishing la pà ªche aller à   (to go) pà ªcher television (TV) la tà ©là ©vision (la tà ©là ©) regarder (to watch) a movie un film regarder (to watch) music la musique à ©couter (to listen), jouer de (to play)