Materials Selection For Automotive Exhaust System Engineering Essay

Materials Selection For Automotive Exhaust System Engineering Essay This assignment looks into the material selection and manufacturing process for an automotive exhaust system considering the operational requirements. Towards the end, the application of alternate material is also discussed. Working Requirements The maximum temperature in an automobile exhaust system is around 750-850 degree celsius. So the selected material for manufacturing the exhaust system should be able to handle temperatures in this range. Also there are various other corrosion factors like high temperature oxidation, de-icing salt contamination and wet corrosion by condensates[mainly towards the tail pipe section]. The exhaust system can mainly be divided into 2 sections based on the working temperature. The hot end[temperatures above 600 degree Celsius] which starts from the manifold till the catalytic converter, and the cold end[temperatures below 600 degree Celsius] which extends from the pre-muffler till the tail pipe. The exhaust system is also subjected to high frequency vibrations due to exhaust gas discharge. Normally, ferrous alloys are used in the manufacturing of exhaust system. These include carbon steel, stainless steel, alloy steels and cast iron. The purpose of adding alloying elements is to help in solid solution strengthening of ferrite, improve the corrosion resistance and other characteristics and the cause the precipitation of alloy carbides. [5] Mild carbon steel was extensively used for the manufacturing of exhaust systems for a considerable period of time. Although mild steel has the properties to withstand exhaust temperature it has very poor corrosion resistance. High exposure to road salt and exhaust condensate can terribly shorten the life span of a mild steel based exhaust system. Also, over the years higher demands in power and environmental safety have seen the demise of mild steel from exhaust systems. Nowadays mild steel is employed in applications where the environment is non-corrosive. Stainless steel has replaced mild steel in exhaust systems today. The ferrous alloying element used here is chromium. The minimum amount of chromium in stainless steel is 10.5%. When stainless steel is heated, chromium forms a protective layer of chromium oxide over the stainless steel surface and delays further oxidation process. The exhaust system in a vehicle is expected to be at its peak performance always and the material failure is a undesirable characteristic for this. Performance and efficiency of a automobile engine is seriously affected by minor changes in the exhaust system. Therefore, it is important that fail proof and efficient materials be used in the construction of automotive exhausts. Materials used for manufacturing of exhaust systems should have the following characteristics: High service temperature, high fatigue strength, high fracture toughness, should be easily machinable and should be economic considering the overall cost of the automobile. Also, the material should be highly resistive to corrosion as the exhaust system is majorly exposed to road salts and condensates from the engine exhaust gases. Failure in the exhaust system can cause loss of back pressure which can significantly affect engine performance parameters.[1] Current trend: Evolution in the automobile industry has also seen the evolution of exhaust systems. From the usual carbon steel exhausts, we can see stainless steel being heavily employed in exhaust systems. From the CES charts, we can see that stainless steel excels over low/medium carbon steel in all properties other than economy. Ferritic stainless steel is used in the manufacture of exhaust systems. Ferritic stainless steel contains chromium as the main alloying element. The percentage of chromium can vary from 10.5% to 18%. These materials are resistant to corrosion and have very low fabrication characteristics. Although, these can be improved by alloying. Grades such as 434 and 444 have improved fabrication properties. Ferritic stainless steel is always used in a annealed state as they cannot be hardened using heat treatment processes. They have vey high resistance to cracking due to stress corrosion. They also exhibit acceptable welding characteristics in thin sections.[1] We can see in detail the different parts of the exhaust system and the material properties below: Exhaust Manifold: The exhaust manifold of a automobile engine is always exposed to hot gases. Cast iron has been in use for the production of exhaust manifolds traditionally. The main characteristics required for the exhaust manifold material include thermal fatigue strength required to withstand the high temperature exhaust gases, oxidation resistance , good fabrication properties and low thermal capacity to enhance the catalytic function. Ferritic stainless steel exhibit all these properties and offers big weight reduction also. The developments in vacuum casting process has helped in the fabrication of stainless steel manifold with section thickness of 2-5mm. Higher demands in pollution control will rise the exhaust temperatures too and therefore, ferritic stainless steel will be in major use for exhaust system manufacturing. Ferritic stainless steel exhibits improves thermal fatigue characteristics when processed by solid solution strengthening with molybdenum or niobium. This process also improve s the oxidation resistance and microstructural stability. Ferritic stainless steel also has cost advantages because of the absence of nickel in its composition. Another variant called the austenite stainless steel is used where ferritic stainless steel is unsuitable. Austenite stainless steel can enhance its properties when enough carbon is added to it. But, the higher cost limits its usage compared to the ferritic variant.[3] Cast iron manifolds can be manufactured by the sand casting process. The solidification of molten cast iron can result in the formation of interstitial voids between the various particles in the cast iron structure. This can lead to particle sliding over each other and as a result a decline in the mechanical properties of the mould. Stress relieving heat treatments are performed inorder to increase the dimensional stability of the material. During heat treatment, the thermal expansion of the material allows the voids to be filled. Although, care should be taken as not to overdo the heat treatment process as too much thermal expansion can bring about more stresses in the material microstructure and this can impair material properties. Changes in microstructure can diminish material properties like thermal fatigue and fracture toughness that can result in the premature failure of the finished product. The alternate material that can be used in exhaust manifold manufacture is ferritic stainless steel. These materials have enhanced properties for exhaust manifold production. The main feature is the low thermal expansion that is one of the major problems faced by cast iron exhaust manifolds. Molybdenum and Niobium alloying has shown tremendous increase in the heat enhancement properties of ferritic stainless steel. Vacuum casting process that is used in the production of ferritic stainless steel manifolds is the factor that increases its cost. Effective methods need to be developed to reduce the tooling and manufacturing cost. Once this is achieved, cast iron exhaust manifolds can be replaced by stainless steel exhaust manifolds that have improved properties and weigh less and can thus adhere to stringent emission norms that come in future. Nowadays stainless steel manifolds are only used in vehicles that call for extreme performance. Commercialisation of this technology is not far a way. Catalytic converter: The catalytic converter is used to clean the exhaust gases and make it free of toxic effects. It is normally exposed to elevated temperatures like 1000 degree Celsius and therefore its durability is a very important factor in proper functioning of the exhaust system. Conventionally the catalytic converters are made of a material called the cordierite monolith that basically acts as the absorbant in it. Cordierite is a silicate and thus the component is manufactured by an extrusion process. Then it is subjected to washcoating where the monolith is submerged in materials such as Al2O3, CeO2, ZrO2 and metals such as platinum, rhodium and palladium. The main properties of the catalytic converter monolith are as follows Fusion point : 1450 degree Celsius Coefficient of Thermal Expansion : 0.002cal/s-cm-oC [low] Thickness of monolith walls : 100 microns Number of cells : 400-900 cpsi The main advantages of the cordierite monolith are lower cost and manufacturing ease. Alternate material for the catalytic converter is stainless steel. Instead of the silicate monolith metal alloy materials are used in the construction of the monolith. These metal monoliths are manufactured by the combination of flat and corrugated layers of the metal alloy. These are then made into the spiral shaped monolith. The exhaust gases escape through the channels formed between the flat and corrugated planes. Washcoating is done in this case also. But the important thing to be remembered is that this process needs to be done before the monolith is made into a spiral shape. This is because the metal monolith is generally smaller in size and that can obstruct the proper washcoating of the entire metallic monolith. The main characteristics of the metallicmonolith are as follows: Fusion point : 1600 degree Celsius [150 degree Celsius more than cordierite] Coefficient of Thermal Expansion : very high[directly influenced by aluminium content in metal alloy] Thickness of monolith walls : 25 microns [less compared to cordierite] Number of cells : 800-1250 cpsi [2] One of the major advantages of the metallic monolith is the high impact resistance. As the catalytic converter is prone to impacts from road surfaces, it is important that the catalytic converter remains intact at all times. The cordierite monolith is very weak compared to metallic monolith in this case. Metallic monoliths also have the advantage of being placed close to the exhaust manifold. This means that they can achieve the operating temperature[around 300 degree Celsius] earlier and thus reduce exhaust contamination. These monoliths can also be developed in smaller sizes compared to the silicate counterparts. Higher service temperature means that metallic monoliths are used in high performance applications where the conditions are very severe. Muffler : The muffler is the final part in the exhaust system. The introduction of catalytic converter has led to the formation of condensates inside the muffler thereby resulting in corrosion. Aluminized carbon steel is employed in the manufacture of the exhaust mufflers traditionally. The exhaust gas condensates have amplified the corrosion rates in the muffler and it is seen that they do not perform to their maximum service life when the catalytic converter is introduced. This normally happens in the short runs of the vehicle where the exhaust gas temperature does not rise high enough to vaporize these condensates. During long runs, the exhaust gas temperature goes over 100 degree Celsius which prevents the formation of condensates and reduces corrosion. Stainless steel mufflers have very high corrosion resistance and the addition of chromium and molybdenum can improve these properties. High production rates can be achieved by the use of stainless steel by tandem mill cold rolling, annealin g and descaling process. Titanium can also be added in small traces to improve muffler properties in stainless steel.[3] Titanium exhaust systems [ a future perspective]: Environmental agencies now prefer guaranteed corrosion resistance on exhaust systems for more than 100,000 miles. Titanium achieves this and is much better than stainless steel systems that are used now. A typical catalytic converter and muffler pipe in stainless steel weighs around 10kg. A redesigned titanium system weighs only around 3.2 kg. This weight saving is very beneficial when considering high performance and high precision automobiles. Pure titanium tube and sheet are the materials of choice for silencers, and pipes. Reduction of weight and cost are achieved by selecting the thinnest gauges of materials consistent with the engineering and acoustic parameters of the exhaust system. Titanium may not be suitable for the entire system, and will most probably be limited to components in which the temperature of metal does not go over 400 degree celsius for longer periods of time. The parts immediately behind the catalytic converter continue to perform well under test. Use of titanium lugs welded to the pipe will certainly prove to be the most efficient method to fix the exhaust to the vehicle frame (via rubber isolators). Material conforming to ASTM Grade 2, (e.g. Timetal 50A) offers the optimum in terms of cost, availability, fabricability, weldability and mechanical properties. Grade 45A is slightly less strong and more ductile than 50A and may be required where extensive forming is part of the manufacturing process e.g. lock seaming (Table 4). Both alloys are fully weldable, require no intermediate or post-forming heat treatment, and are available in wide sheet coil. These alloys are also used to manufacture low-cost continuously welded tube.   Properties of pure titanium 45A and 50A 45A 50A Thermal expansion (10-6degree Celsius) 8.9 8.9 Hardness (HV) 140-170 160-200 Tensile Modulus ( 103N.mm2) 103 103 Density ( g.cm-3) 4.51 4.51 Specific Heat( J.kg-1.oC-1) 519 519 RA min (%) 40 35 Titanium Production: Pure titanium is cold formable, and sheets or tube can be shaped readily at room temperature using techniques and equipment that are normally for steel. Following factors must be taken into consideration while machining titanium.  ·Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  The ductility of titanium is generally less than that of steel. More generous bend radii may be required during bending applications.  ·Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  The modulus of elasticity of titanium is about half that of steel. This means that titanium will return back to original state after forming. Compensation for this can be done by slight overforming.  ·Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Titanium tends to gall against unlubricated forming tools. Proper lubrication of the tool can solve this problem. Both lock seaming and resistance welding are suitable to join the catalytic converter, and traditional TIG is suitable to seal the ends and pipe joints with a torch trailing shield to the external surface of the box end joints. Production Economy: A leading exhaust system manufacturer in the United States, successfully rolled and seam welded a batch of titanium boxes at one of its production units. This was done with no extra cost when compared with the production of steel components. It was also seen that the bending units that are currently employed for the bending of steel are suitable in the case of titanium also. The only factor is the procurement cost of titanium and therefore significant efforts are necessary to bring down tooling and manufacturing costs.[3] Conclusion: It can be concluded that stainless steel can replace conventional materials in automotive exhaust systems. We have to count on developments in tooling and manufacturing methods that can bring down overall costs to minimum. Stainless steel is easily the best alternative in service aspects of the exhaust system. High performance materials like titanium may also come into commercial production soon. Improved thermal, mechanical and chemical properties are major factors that govern material selection for an exhaust system.

Managed Care, Physicians, and Patients :: Healthcare

Give three examples of common assertions about managed care impact on physicians and physician/ patient interaction. Explain how these assertions are proven true or false by evidence. Kongstvedt (2007) argues that managed care has impacted the way in which patient and physicians interact .Now, physicians are held more accountable, and patients are more actively involved in their care .The following are three examples of common assertions about managed care impact on physicians and patient interaction. However, these assertions are proven true or false by evidence. 1. Many critics of managed care argue that utilization review personnel decisions in regards to necessary treatment overrule doctors’ decisions frequently and coverage denial rates for physician recommendations are very low. However, Kongstvedt (2007) states that a national survey that was carried out with over 2,000 physicians caring for patients plans utilizing manage care techniques discredit this claim. In fact, the survey revealed that the final coverage denial rate for physician recommendations was at most 3% within eight categories and much less for most categories of care.

Murdering of Innocents

Chapter Two begins with the introduction of Thomas Gradgrind, â€Å"a man of realitiesSfacts and calculations. † He always introduces himself as Mr. Gradgrind and spends his time in constant cogitation. He is the Speaker, previously unnamed and he now takes it as his duty to educate the children (â€Å"little pitchers before him†). He identifies a student, called Girl number twenty, who replies that her name is Sissy Jupe. Gradgrind corrects her that her name is Cecilia regardless of what her father calls her. Jupe's father is involved in a horse-riding circus and this is not respectable†¹in Gradgrind's opinion. He advises Cecilia to refer to her father as a â€Å"farrier† (the person who shoes a horse) or perhaps, a â€Å"veterinary surgeon. † The lesson continues with Gradgrind's command: â€Å"Give me your definition of a horse. † While Girl number twenty knows what a horse is, she is unable to define one. Another child in the class, a boy called Bitzer, easily defines the animal by means of biological classifications (quadruped, graminivorous, etc. ). After this, the third gentleman steps forward. He is a government officer as well as a famous boxer and he is known for his alert belligerence. His job is to remove â€Å"fancy† and â€Å"imagination† from the minds of the children. They learn that it is nonsense to decorate a room with representations of horses because horses do not walk up and down the sides of rooms in reality. Sissy Jupe is a slow learner, among the group of stragglers who admit that they would dare to carpet a room with representations of flowers because she is â€Å"fond† of them. Sissy is taught that she must not â€Å"fancy† and that she is â€Å"to be in all things regulated and governed by fact. † After the gentleman finishes his speech, the schoolteacher, Mr. M'Choakumchild, begins his instruction. He has been trained in a schoolteacher-factory and has been conditioned to be dry, inflexible and uninspiring†¹but full of hard facts. His primary job in these preparatory lessons is to find â€Å"Fancy† in the minds of the children and eradicate it. Analysis: â€Å"Murdering the Innocents† replaces the suspense of the previous chapter by establishing names and identities for the previously anonymous social roles that were presented earlier. As is to be expected from Dickens, the names of the characters are emblematic of their personality; usually, Dickens' haracters can be described as innocent, villainous or unaware of the moral dilemmas of the story that surrounds them. The characters' names are almost always an immediate indication of where the character fits on Dickens' moral spectrum. Thomas Gradgrind, â€Å"a man of realities† is a hard educator who grinds his students through a factory-like process, hoping to produce graduates (grads). Additionally, Gradgrind is a â€Å"doubting Thomas†Ã¢â‚¬ ¹much like the Biblical apostle who resisted belief in the resurrection, this Thomas urges that students depend exclusively upon the evidence in sight. He dismisses faith, fancy, belief, emotion and trust at once. Mr. M'Choakumchild is plainly villainous and he resembles the sort of fantastic ogres he'd prefer students took no stock in. Cecilia (Sissy) Jupe is unlike the other characters in almost every possible way. While there are other female students, she is the only female identified thus far in the novel. Unlike the boy â€Å"Bitzer† (who has the name of a horse), Sissy has a nickname and at least in this chapter, she is the lone embodiment of â€Å"fancy† at the same time that she is the single female presented as a contrast to the row of hardened mathematical men. Her character is, of course, a romanticized figure. Despite the political critique of Dickens' simplification and over-idealization of females and children (and girls, especially), Cecilia's character does have some depth that allows her development later in the novel. Her last name, â€Å"Jupe,† comes from the French word for â€Å"skirts† and her first name, Cecilia, represents the sainted patroness of music. Especially as she is a member of a traveling circus, we can expect Cecilia to represent â€Å"Art† and â€Å"Fancy† in contrast to M'Choakumchild, one of 141 schoolmasters who â€Å"had been lately turned at the same time, in the same factory, on the same principles, like so many pianoforte legs. Besides the allusion to St. Cecilia, Dickens alludes to Morgiana, a character in the classic story † Ali Baba and the Forty Thieves†Ã¢â‚¬ ¹one of the Arabian Nights tales. The reader should always note the irony in Dickens' allusions: while Dickens' characters argue against fanciful literature, Dickens' is relying upon it to compose his story. In this case, Dickens' simile presents M'Choakumchild's search for â€Å"the robber Fancy† in terms of Morgiana's searching for (and hiding of) the thieves in â€Å"Ali Baba. The metaphor of the children as eager â€Å"vessels† is made explicit when the â€Å"vessels† before M'Choakumchild become the â€Å"jars† before Morgiana. And the motif of robbers and villains is finalized when we remember that Ali Baba and the forty thieves were more hero than criminal. M'Choakumchild is labeled â€Å"gentleman† but his intention to seek and destroy â€Å"the robber Fancy lurking within† makes â€Å"the robber Fancy† (childish imagination) a more noble personification. Instead, the teachers are the ones who seem criminal. The most important allusion of the chapter is the title: â€Å"Murdering the Innocents. † The reader should expect Dickens work to be full of Biblical and Christian allusions as he is writing to a largely sentimental popular audience. While the reference may be more inaccessible, erudite or unrecognizable for modern young readers, Dickens' 1854 British audience immediately saw the reference to King Herod. Soon after the birth of Christ, Herod fears for his throne and has all of the male babies in Bethlehem executed (in the hopes of murdering the Christ child). In literary circles, the phrase â€Å"murder of the innocents† is exclusively used to describe this Biblical story. While the students are not literally danger (M'Choakumchild), their childish imagination has been targeted for annihilation. This completes the archetype of youth vs. age, and foreshadows that whoever is being targeted and singled out (Cecilia Jupe and her imagination) will ultimately escape this tyrant, but other innocents will be less fortunate (Bitzer). But we might expect as much from the same author who had written A Christmas Carol a decade before. The major theme of the chapter can be easily inferred from Dickens' description of Cecilia in the classroom. The â€Å"horses† and carpeted â€Å"flowers† are all double symbols of her femininity and youth, but most important, Cecilia represents Art in opposition to mechanization. Dickens is not arguing against education, science or progress. He is arguing against a mode of factory-style, mind-numbing, grad-grinding production that takes the fun out of life. But even worse than the loss of â€Å"fun† or â€Å"leisure,† Dickens is arguing that art requires an inquisitive and desiring mind. Especially as Dickens is known to have read and enjoyed Arabian Nights in his youth, we can see a bit of autobiography in his tender treatment of Cecilia†¹perhaps if he had come under a Mr. M'Choakumchild, he would have proved incapable of becoming an artist. The life of modern mankind is presented very negatively and ignorantly by Matthew Arnold in the poem Dover Beach by the fact that religious faith evanesce with the Industrial Revolution. Arnold creates the image of the dark future for the people without unwavering faith or religion. Modern men are bastardised with the thought that new the Industrial Revolution will give them advantage over nature. This thought of gaining superiority made humans arrogant by which this appearance is broken by the reality of nature’s dominance. People also seem ignorant with the wishful thought. These pebbles which ‘the waves draw back, and fling’ are completely powerless and are thrown around by the waves that move these â€Å"pebbles† at ease. Arnold uses pebbles as a metaphor for humans to show the inferiority in comparison to nature. The ignorance of humans is emphasised by the historical allusion to Peloponnesian War. In the dark, soldiers could not differentiate between their own army and the opponents; and so they killed their own soldiers. This is used by the poet to show the stupidity of modern man throwing away the religion which was everything to people before the Industrial Revolution; something to believe and rely on when people prayed. However, this old belief is thrown away and Arnold sees it as a very naive decision. The Industrial Revolution gave the source of arrogance and confidence which took place among the Western countries. This revolution was revolutionary itself; humans could mass produce, with improved quality, and at ease. These machineries became the limbs of human society. What came with the industrial revolution was the idea of realism. People could nearly produce goods to near-original standards, all thanks to improved technologies and science, and hence began to doubt the existence of God and supernatural beings. Realism contrasts the theology which is all about belief without questioning that God exists; and people believed it before the times of the machineries. It gave people hope and modesty under the mighty existence of God. However both hope and modesty disappeared with the Industrial Revolution which Arnold laments for. Bitterness is suggested when Arnold exclaims ‘Ah, love’ to show that in this changing world, one can only rely on the partner, and be trustful and true. Sarcasm is used to describe the modern world as a ‘land of dreams’ as there is no more hope for the world, as there is no more faith. As the poem proceeds, the transition of mood is noticeable as the grief of the loss of faith extends to a sense of resignation towards the end and having a sarcastic, sour approach to the ssue. The ‘tremulous cadence slow’ helps to convey the gradual process of the wane of doctrine which adds to the idea that the change of people’s lives is almost unnoticeable. This gradual process hurts Arnold because people are caught unaware of the changes taking place and so do not think it is particularly wrong and sinful. Arnold presents his sorrow with the historical al lusion to Sophocles who, was a Greek playwright, had heard the sound of waves crashing as the ‘eternal note of sadness’. The ‘sadness’ of the mankind turning away from religious beliefs is a parallel to the ‘melancholy†¦ withdrawing roar†¦retreating’ of the waves. Before the development of science and technology, people had truly believed in the religion and thought that they were in total control of god. The metaphor ‘Sea of Faith’ which presents the religious faith people have, used to be ‘full and round Earth’s shore’ but now is ‘retreating†¦ down the vast edges’ which shows the decreasing religious beliefs. Arnold points out that, without faith, humans are ‘naked’ and have no protection and defence which reflects the vulnerability of man and their lives. With carefully chosen words, Arnold presents the uncertainty of the future of humans. The new industrialised world seems â€Å"so various, so beautiful, so new† but it is again a mere appearance. The reality is that this mechanic, stiff world will have â€Å"neither joy, nor love, nor light† because this mechanics cannot feel love, hence no joy, and no vision as humans need love and the warm characteristics of humanity. It is thus deducible that the future will have no â€Å"certitude, nor peace, nor help for pain† which are the essentialities of humans. Humans can only survive the harsh world when everybody believes and trusts each other, and this will be broken with the introduction of industrialisation. This change of the world will bring â€Å"confused alarms on struggle and flight† which creates an imagery of a â€Å"darkling plain†; a dark vision for humans. Furthermore, the â€Å"turbid† ebb and flow shows the cloudy, uncertain future of ‘ebb and flow’ which is the repetitive cycles of nature. Can humans only survive when they make harmony with the nature, and to go against the natural cycles can only mean extinction of humans. The ‘cliffs’ of England ‘gleams’ and ‘glimmers’; gleams and glimmers have a sense of shakiness, precariousness and unknown which echoes the uncertain modern man. Also the alliteration of ‘g’ and ‘m’ creates a stuttering tone which adds to the idea of uncertainty. This imagery portrays the withering away of cliffs as a decline of religious beliefs and whatsmore, deterioration of the Earth itself as humans exploit resources out of the Earth which the modern development enabled men to do. The flaws of modernism and realism are expressed in this poem. The flow of the poem is cut off by uses of caesura which is a parallel to the imperfect modern world. Arnold gives a hint that modernization of the world will have some flaws which will inevitably bring loss of faith and result in loss of equilibrium. In science, there is no hope; everything is measured out and exact. Hence in the modern world reality there can be no hope as it looks vain. Again, Arnold sympathises with the loss of hope in reality. In a different sense, the calm, naturalistic description of a beach at night in the first stanza is the appearance which contrasts to the reality that is sad, unhopeful, ‘retreating’ and ‘tremulous’. Human beings are inferior over nature and the spiritual beliefs as to an extent that people cannot control anything. The abandonment of the doctrine of religion with the help of the Industrial Revolution is only a vain act against the power overwhelming nature. Religion and faith should remain in humanity and ignoring it should result in the uncertainty and vulnerability of modern man.

20 Words Meaning Being or Existing in the Past

20 Words Meaning Being or Existing in the Past 20 Words Meaning Being or Existing in the Past 20 Words Meaning Being or Existing in the Past By Mark Nichol This list features former and eighteen other adjectives (and a prefix) that can be used to refer to a position no longer held or a state no longer active, exclusive of the synonyms for original. 1. antecedent: Though this word is usually seen in noun form, it can also be an adjective, as in â€Å"She wants to answer the antecedent question.† 2. earlier: This comparative of early, like most words on this list, can function as an adjective as well as an adverb; in the former usage, one can say, for example, â€Å"The earlier iteration had many flaws.† 3. erstwhile: This somewhat stuffy, self-conscious synonym for former was originally an adverb, as in â€Å"The two were erstwhile adversarial† but has been in use as an adjective since the early 1900s. The first syllable from this word from Old English is from the superlative for ere (â€Å"before†). 4. ex-: This prefix is attached, nearly always with a hyphen, to a noun to signify that a status is no longer current, as in â€Å"All four living ex-presidents attended the event.† (The exception is when an en dash is used in place of the hyphen to signal that what follows the prefix is an open compound, as in â€Å"All four living ex–vice presidents attended the event.† It might be better, however, just to use former or another alternative.) The prefix, which originally meant â€Å"from† or â€Å"out of† but now has several senses, is also sometimes used as a stand-alone word, especially in reference to a former significant other, as in â€Å"Oh, I saw your ex the other day.† 5. former: This is the default word to describe the sense of something no longer being what it was; it can also be used as the antonym of latter to refer to the first of two things. 6. late: When used on its own to modify a person’s name (â€Å"the late John Smith†), it means that the person is deceased. â€Å"Late of,† however, is an outdated way of saying that someone is no longer associated with something, as in â€Å"Mary Jones, late of Centerville† (meaning that she recently lived there). 7. onetime: This synonym of former (â€Å"Mary Jones is a onetime resident of Centerville†) may also mean â€Å"done or happening one time only†). The word is sometimes hyphenated when the latter meaning is intended. 8. old: Old distinguishes something from something else from an earlier time that was replaced, as in â€Å"I think that the old design looks better.† 9. original: This word can be used in place of former or a synonym to refer to an initial state, as in â€Å"The original plans called for a large entrance.† 10. other: This word occasionally substitutes for former, as in â€Å"In other times, we might not have given it a second thought†; a similar usage is, for example, â€Å"the other day,† referring to a recent day. 11. past: This word is used narrowly in the sense of someone who no longer holds a position, as in â€Å"past president.† 12. precedent: Like the similar word antecedent, this term is usually used as a noun but can function as an adjective, as in â€Å"A precedent event in her life turned out to be a character-defining one.† 13. preceding: Preceding has the same sense as precedent and is used more commonly. 14. preexisting: This word means â€Å"existing in an earlier time.† (Note that the prefix pre- is not attached to the root word with a hyphen.) 15. previous: Previous can mean â€Å"existing before in general† or â€Å"existing immediately before,† depending on whether one writes, for example, â€Å"a previous administration† or â€Å"the previous administration.† 16. prior: This word is identical in meaning to previous, though it is less likely than that word to be used to refer to mean â€Å"immediately previous†; it also has the sense, rarely employed, of â€Å"being more important because it came first.† 17. quondam: This direct borrowing from Latin was originally an adverb and a noun, but those usages are obsolete, and adjectival use is rare and often considered overly formal. 18. sometime: Sometime began as an adverb. Later, it acquired the sense of â€Å"at some future time,† as in â€Å"I’ll see you again sometime,† and finally developed an adjectival sense. 19. then: The adverbial use of this word (â€Å"I’ll go, then†) and its function as a conjunction (â€Å"First, I waved, and then I called out to her†) were followed by the development as an adjective meaning â€Å"being at that time†; it should be used in place of former or most other synonyms to indicate that the state existed during the time being discussed, as in â€Å"In 1968, then California governor Ronald Reagan considered running for president.† (Note that then is not hyphenated to the following word.) 20. whilom: This synonym for former (and formerly) is archaic and rarely used anymore. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! 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Free Essays on Mapp V Ohio

,’ valueless and undeserving of mention in a perpetual charter of inestimable human liberties, so too, without that rule the freedom from state invasions of privacy would be†¦ ephemeral†¦Ã¢â‚¬  The exclusionary rule not only applies to federal cases, it also applies to state criminal proceedings. This prohibits... Free Essays on Mapp V Ohio Free Essays on Mapp V Ohio Mapp V. Ohio 367 U.S. 643 (1961) Facts: Mapp was convicted of possession of lewd and lascivious books, pictures, and photographs in violation of Ohio law. Three Cleveland police officers went to Mapp’s resident based on information that a person who was wanted in connection with a recent bombing was hiding out in her home. The officers knocked on the door and demanded entrance, but Mapp, telephoning her attorney, refused to admit them without a warrant. The officers again sought entrance three hours later, after the arrival of more police. When Mapp did not respond, the officers broke the door open. Mapp’s attorney arrived but was denied access to his client. Mapp demanded to see the search warrant the police claimed to possess. When a paper supposed to be the warrant was held up by one of the officers. Mapp grabbed the paper and places it in her bosom. A struggle ensued and the paper recovered after Mapp was handcuffed for being belligerent. A search of the house produced a trunk that contained obscen e materials. The materials were admitted into evidence at the trail and Mapp was convicted of possession of obscene materials. Issue: Fourth Amendment (Exclusionary Rule) Court: United States Supreme Court Reason; â€Å"Since the Fourth Amendment’s right of privacy has been declared enforceable against the States through the Due Process Clause of the [Fourteenth Amendment], it is enforceable against them by the same sanction of exclusion as is used against the Federal Government. Were it otherwise, then just as without the Week rule the assurance against unreasonable searches and seizures would be ‘a form of words,’ valueless and undeserving of mention in a perpetual charter of inestimable human liberties, so too, without that rule the freedom from state invasions of privacy would be†¦ ephemeral†¦Ã¢â‚¬  The exclusionary rule not only applies to federal cases, it also applies to state criminal proceedings. This prohibits...

Residual Income as a measure of managerial performance. Include Essay

Residual Income as a measure of managerial performance. Include examples of usage today and advantages and disadvantages - Essay Example In business, residual income represents a specific financial amount derived from an equation which subtracts invested capital from total, pre-tax profitability (Accaglobal.com, 1999). Where the traditional return on investment (ROI) template, which calculates a percentage by dividing the average operating assets from net operating income, residual income is represented in actual dollars through its calculation. Professionals argue that residual income (RI) may not necessarily reflect the total performance of a managerial professional, hence there is the debate as to whether compensation directly linked to RI totals is a fair measure of reward for performance. This paper examines the contemporary usage of residual income as a performance measure. There are several viable calculations to determine residual income (RI), with the most common being operating income minus the required return on investment in dollars (Marshall, McManus & Viele, 2006). A second method is subtracting required income from actual income, representing a final financial (not percentage) total, indicating either a negative or positive residual income (Economist, 1996). For instance, if the actual income of the firm is $100,000 and required income (often calculated from ROI) is $50,000, the firm has experienced a residual income increase of $50,000, which may indicate that the company executive leadership has made positive strides in boosting profitability. When ROI is used in the equation to determine residual income, positive RI occurs when actual ROI is greater than the minimum required ROI. These calculations may sound very simplistic and relatively straightforward, however, calculating residual income is not always a fair measure of total executive performance, especially when a particular company has experienced years of negative residual income. For instance, assume that a firm maintained a negative residual income for

Techniques lab Report Example | Topics and Well Written Essays - 1000 words

Techniques - Lab Report Example Calculations performed on the changes in mass revealed that the experimental mass of the NaCl was 1.464 g. The -1.942% error between the two results was attributed to experimental errors arising from the improper use of the pipets during the transfer of the solution to the evaporating dish for heating. The results obtained showed that the difference in the masses between the expected and experimental results to be small (-0.029 g), resulting in a relatively small % error of -1.942%. The % error was caused by systematic errors resulting from improper use of the pipet during the transfer on the 25 mL NaCl solution to the evaporating dish. Minute air bubbles might have been sucked together with the NaCl solution, resulting in a reduced amount of NaCl being heated at the end, thus lowering the final mass. The pipet used in the experiment has a precision of uncertainty of  ±0.01 mL; therefore the 25 mL taken from the volumetric flask was between 24.99 mL – 25.01 mL. This uncertainty is relatively low, making the pipet’s readings relatively precise, thus reducing the chances of random errors resulting from observational mistakes during the filling up of the pipet. a. Filling the 100 mL volumetric flask beyond the mark would lead to a lower actual (experimental) molarity. This is because adding more water will make the solution more dilute, thus lowering the molarity. b. The density of the solution would decrease if the volumetric flask was topped beyond the mark because the density if governed by the formula Density = Mass / Volume1. Therefore, increasing the volume would lead to a subsequent decrease in the density. a. Having the liquid level in the pipet being below the line would lead to a reduction of the mass of the NaCl obtained after the subsequent heating because the amount of NaCl pipet is less than the required amount. c. Using the pipet to deliver the NaCl solution to