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Tuesday, August 25, 2020
How To Handle Gossip About a Coworker
Step by step instructions to Handle Gossip About a Coworker Tattle occurs. What's more, there is consistently somebody in each office who just canââ¬â¢t help however spread it. Furthermore, obviously, it very well may be entertaining. Be that as it may, it very well may be similarly destructive and can harm vocations not simply the personââ¬â¢s being tattled about. How to pursue the more responsible option? Here are a couple of valuable systems to keep your head over the fray.1. Set the tone.You should be the adult particularly if youââ¬â¢re an administrator or manager and will set a model for your subordinates. However anybody can do this. On the off chance that individuals begin theorizing uncontrollably about organization issues-or more regrettable tattling about colleagues, managers, and friends, you can be simply the first to evacuate and make a stride back. This may very well show them, by model, the mistake of their ways-without your idiom anything by and large. Donââ¬â¢t let yourself be attracted. On the off chance that yo u canââ¬â¢t leave a discussion, attempt an unpretentious difference in topic.2. Be available to negativity.People are bound to talk about you in the event that you donââ¬â¢t appear to be available to hearing their interests or work environment issues (on account of being a manager) or in the event that you donââ¬â¢t appear to be available to useful analysis yourself. Be as straightforward as conceivable when youââ¬â¢re in a place of intensity. What's more, regardless of what your activity title, keep the lines of correspondence open.3. Donââ¬â¢t rebuff the middleman.If youââ¬â¢re a chief and one worker ventures forward to address an issue or draw an issue out into the open, donââ¬â¢t rebuff that individual for doing as such. That personââ¬â¢s associates will probably consider this to be an indication of your being aloof and out of line. Prompt: gossip.4. Defy the source.Sometimes it gets important to stand up to the gossiper, regardless of whether the tattle is about you. Most gossipers proceed with their jabbering since they accept there are no negative results. Be that as it may, on the off chance that you let them know youââ¬â¢re on to what theyââ¬â¢re up to-and let them know your sentiments on the issue chances are they may stop all alone. On the off chance that you need to reprimand them for their conduct, make your analysis about the issue, not them by and by. Donââ¬â¢t simply state: you tattled! that isn't right! Attempt rather: Iââ¬â¢m worried about the tattle and Iââ¬â¢m trusting we can stop it. 5. Donââ¬â¢t act naturally righteous.Itââ¬â¢s fine and dandy to go high. Itââ¬â¢s what you ought to do. In any case, on the off chance that you begin to get extremely affected or devout about your own great direct despite overflowing and wild tattle, youââ¬â¢re not going to make numerous partners. Remain easygoing when managing tattle, in any event, when attempting to be a genuine model. Itââ¬â¢s not about you, all things considered!
Saturday, August 22, 2020
Musical Theatre Essay -- essays research papers
Young lady Crazy (#14) à à à à à The melodic ââ¬Å"Girl Crazyâ⬠was about a kid named Danny Churchill who lived in New York. His father was stressed over his way with ladies so he sent him to Custerville, AZ to get him away from them. Danny was to live on the family buddy farm called ââ¬Å"The Buzzards.â⬠à à à à à On his approach to AZ, Danny rode in a taxi. The driverââ¬â¢s name was Gieber Goldfarb. He was known for his extremely terrible Yiddish jokes. He in the end began to look all starry eyed at a lady named Patsy West, who was likewise a nosey phone administrator. à à à à à After Danny gets to Custerville, he meets the post-young lady named Molly Gray. He was infatuated with her, despite the fact that he had quite recently left his former sweetheart in New York. Her name was Tess Hardy. Danny had taken Tess away from her former sweetheart; his name was Sam Mason. Sam was steamed at this, so when he knew about Dannyââ¬â¢s whereabouts, he came to take Molly from him. It worked for a brief period, until Molly acknowledged she ought to be with Danny. à à à à à There were likewise two individuals named Slick and Kate Fothergill. Smooth dealt with the betting room at ââ¬Å"The Buzzardsâ⬠that Danny opened to make the spot to some degree a gathering house. Kate was a dance club artist that sang in Dannyââ¬â¢s club. à à à à à There were two others in the story that made it fascinating and humorous. Their names were Lank and Pete. They were the town scalawags and neighborhood hooligans. Toward the end, these young men end up in prison. Holly Conant Of Thee I Sing (#16) à à à à à In the melodic ââ¬Å"Of Thee I Sing,â⬠there were numerous characters. The lead was most likely John P. Wintergreen. It is an account of Wintergreen running for president and all the accidents he had with ladies. There were a couple of individuals on his political board of trustees. Their names were Louis Lippman, Francis X. Gilhooley, Sen. Robert Lyons, Sen. Carver Jones, and Matthew Arnold Fulton, the director of the board of trustees. Alexander Throttlebottom was the VP. à à à à à The story was about a national delight challenge and the champ got the opportunity to be the primary woman. Not long before the victor was reported, John met a young lady named Mary Turner. Mary was the secretary for the excellence challenge. The two quickly began to look all starry eyed at. à à à à à The champ of the challenge was Diana Devereaux. After the victor was reported, ... ...II, Scene IV, there is a ton of petition and singing, attempting to muffle the sound of the breeze and tempest. Clara is exceptionally frightened for Jake. The entirety of the unexpected, they hear a thump at the entryway and itââ¬â¢s Crown. Bess and Porgy had thought he had passed on in the tempest. He come in and begins criticizing God. He reveals to Bess that she will be with him until the end of time. à à à à à Bess sees Jakes pontoon outside the window. Clara gives her child to Bess and races to Jake. Crown, in the wake of being tested, follows Clara. à à à à à This started Act III. It was in the setting of a memorial service. It was being held for Jake, Clara, and Crown. Be that as it may, Crown isnââ¬â¢t dead! Porgy knows this and stows away so he can assault him and slaughter him. He does in the long run, after a long battle. à à à à à The analysts take Porgy (in Scene II) to distinguish Crownââ¬â¢s body. While he is gone, Sporting Life offers himself to Bess (just as his medications). At the point when Porgy returns, after seven days, he was rich from playing dice in prison. He searches all over for Bess, just to find that she had taken Sporting Life up on his offer and sheââ¬â¢s in New York. Porgy promises that he will discover herâ⬠¦and the story closes. Melodic Theater Essay - papers inquire about papers Young lady Crazy (#14) à à à à à The melodic ââ¬Å"Girl Crazyâ⬠was about a kid named Danny Churchill who lived in New York. His father was stressed over his way with ladies so he sent him to Custerville, AZ to get him away from them. Danny was to live on the family man farm called ââ¬Å"The Buzzards.â⬠à à à à à On his approach to AZ, Danny rode in a taxi. The driverââ¬â¢s name was Gieber Goldfarb. He was known for his awful Yiddish jokes. He in the long run became hopelessly enamored with a lady named Patsy West, who was likewise a nosey phone administrator. à à à à à After Danny gets to Custerville, he meets the post-young lady named Molly Gray. He was infatuated with her, in spite of the fact that he had recently left his former sweetheart in New York. Her name was Tess Hardy. Danny had taken Tess away from her former beau; his name was Sam Mason. Sam was extremely annoyed with this, so when he knew about Dannyââ¬â¢s whereabouts, he came to take Molly from him. It worked for a brief period, until Molly acknowledged she ought to be with Danny. à à à à à There were likewise two individuals named Slick and Kate Fothergill. Smooth dealt with the betting room at ââ¬Å"The Buzzardsâ⬠that Danny opened to make the spot to some degree a gathering house. Kate was a dance club artist that sang in Dannyââ¬â¢s club. à à à à à There were two others in the story that made it fascinating and entertaining. Their names were Lank and Pete. They were the town lowlifess and neighborhood hooligans. Toward the end, these young men end up in prison. Holly Conant Of Thee I Sing (#16) à à à à à In the melodic ââ¬Å"Of Thee I Sing,â⬠there were numerous characters. The lead was most likely John P. Wintergreen. It is an account of Wintergreen running for president and all the accidents he had with ladies. There were a couple of individuals on his political board. Their names were Louis Lippman, Francis X. Gilhooley, Sen. Robert Lyons, Sen. Carver Jones, and Matthew Arnold Fulton, the executive of the advisory group. Alexander Throttlebottom was the VP. à à à à à The story was about a national stunner challenge and the champ got the chance to be the primary woman. Not long before the victor was reported, John met a young lady named Mary Turner. Mary was the secretary for the magnificence challenge. The two quickly began to look all starry eyed at. à à à à à The champ of the challenge was Diana Devereaux. After the champ was declared, ... ...II, Scene IV, there is a ton of supplication and singing, attempting to overwhelm the sound of the breeze and tempest. Clara is terrified for Jake. The entirety of the abrupt, they hear a thump at the entryway and itââ¬â¢s Crown. Bess and Porgy had thought he had kicked the bucket in the tempest. He come in and begins tearing down God. He discloses to Bess that she will be with him for eternity. à à à à à Bess sees Jakes vessel outside the window. Clara gives her child to Bess and rushes to Jake. Crown, in the wake of being tested, follows Clara. à à à à à This started Act III. It was in the setting of a burial service. It was being held for Jake, Clara, and Crown. Be that as it may, Crown isnââ¬â¢t dead! Porgy knows this and covers up so he can assault him and slaughter him. He does inevitably, after a long battle. à à à à à The criminologists take Porgy (in Scene II) to recognize Crownââ¬â¢s body. While he is gone, Sporting Life offers himself to Bess (just as his medications). At the point when Porgy returns, after seven days, he was rich from playing dice in prison. He searches all over for Bess, just to find that she had taken Sporting Life up on his offer and sheââ¬â¢s in New York. Porgy promises that he will discover herâ⬠¦and the story closes.
Monday, August 3, 2020
Scrolling Is the New Smoking
Scrolling Is the New Smoking Youre eating dinner with a friend at your favorite restaurant. Amid the sounds of utensils and dishes and mastication, you hear the muffled ring of the mobile phone in your friends pocket. Most people wouldnt stop the conversation to answer their phone in front of you. Even if it was an emergency, they would step away from the table to take the call. Why, then, dont we extend the same consideration to text messages, emails, and tweets? Look around the next time youre in line at Chipotle, Whole Foods, or Exxon: our addictions are showing. A generation ago, nearly everyone casually puffed cigarettes throughout the day. Today, indoor smoking seems crazy, but its been replaced by the captivating glow of our four-inch screens. Damn, perhaps scrolling is the new smoking. Now look around again. Take in the room, breathe. Why isnt anybody smiling? If the telos of our technology is connection, then why do we let our devices create a smokescreen between us? Theres been much talk about building a wall lately, but perhaps weve already built oneâ"an attention barrier between us and the people in our everyday lives. To tear down this glowing wall, Ive been trying something different lately: anytime I must respond to a messageâ"at home, at the office, or at the local burrito jointâ"I simply say, Please excuse me while I step outside to take this message, just like I would if I needed to make a call (or if I decided to take up smoking). It sounds silly at first, but this choice forces me to prioritize that which is urgent versus that which is important. When scrutinized, our urgent tasks are rarely important. Plus, my friends respect my good manners, and they almost always extend the same courtesy back to me. Subscribe to The Minimalists via email.
Saturday, May 23, 2020
Exercise Recasting a Paragraph in the Future Tense
Verbs are easy to transform and combine, and tenses shift to reflect different meanings to describe when things have happened or will happen. Practice converting verb conjugations increase skill with English and makes it easier to proofread for errors in verb agreement. This exercise will give you practice in working with verb tensesââ¬âin this case, changing the past forms of verbs to the future. Instructions The following paragraph is a fanciful account of a students visit to Buckingham Palace to visit the Queen of England. Rewrite the paragraph as if these imaginary incidents from the past will instead occur sometime in the future. In other words, change the form of each main verb from the past tense to the future (in most cases, will plus the present form of the verb). When youre done, compare your new paragraph with the suggested revision on page two. Example Original: I traveled to London to visit the Queen of England. Recast: I will travel to London to visit the Queen of England. Visiting Her Majesty I traveled to London to visit the Queen of England. Being a clever fellow, I disguised myself as a prince and walked into Buckingham Palace as if I owned it. After receiving directions from aà chambermaid, I stepped into the Queens bedroom and surprised Her Royal Highness with a hearty slap on the back. Then, of course, I tipped my hat, bowed, and delivered the usual compliments. After uncorking a bottle of champagne, we exchanged pleasantries and talked about our families for more than an hour. I showed her my photograph album and my stamp collection, and she showed me her historicà collectionà of jewels. After a thoroughly entertaining visit, I traded email addresses with Her Majesty and then kissed her goodbyeââ¬âon the fingertips of her white gloves, of course. Answer Key The following paragraph offers sample answers (in bold) to the exercise to compare revisions and style choices when recasting into the future tense. "Visiting Her Majesty" Recast in the Future Tense I will travel to London to visit the Queen of England. Being a clever fellow, I will disguise myself as a prince and walk into Buckingham Palace as if I owned it. After receiving directions from aà chambermaid, I will step into the Queens bedroom and surprise Her Royal Highness with a hearty slap on the back. Then, of course, I will tip my hat, bow, and deliver the usual compliments. After uncorking a bottle of champagne, we will exchange pleasantries and talk about our families for more than an hour. I will show her my photograph album and my stamp collection, and she will show me herà historicà collectionà of jewels. After a thoroughly entertaining visit, I will tradeà email addresses with Her Majesty and then kiss her goodbyeââ¬âon the fingertips of her white gloves, of course.
Monday, May 11, 2020
Whats a Good SAT Literature Subject Test Score
What SAT Literature Subject Test score you need to get into a top college or to earn college credit will vary from school to school. The mean score in 2016 was a 599, significantly higher than the mean score on the general SAT reading section. The table at the bottom of the page shows the correlation between Literature SAT scores and the percentile ranking of students who took the exam. For example, 61 percent of students scored a 660 or below on the exam.à While no such tool exists for the Literature exam, you can use thisà free calculator from Cappexà to learn your chances of getting into specific colleges based on your GPA and general SAT scores. SAT Subject Test scores arent comparable to general SAT scores because the subject tests tend to be taken by a higher percentage of high-achieving students than the SAT. Whereas a large number of colleges and universities require SAT or ACT scores, mostly elite and highly selective schools require SAT Subject Test scores. As a result, the average scores for SAT Subject Tests are significantly higher than those for the regular SAT. For the SAT Literature Subject Test, Compare, for example, the mean score of 599 on the Literature Subject Test with a mean score of about 500 for the regular SAT critical reading section. Its also worth noting that the mean score on the Literature subject test has been edging upward in recent years--it is over 30 points higher than it was just two years ago. Most colleges do not publicize their SAT Subject Test admissions data. However, for elite colleges you will ideally have scores in the 700s. Here are what a few colleges say about the SAT Subject Tests: Middlebury College: We are accustomed to seeing ... SAT IIs that range from the low to middle 700s (from Middlebury admission FAQs)Williams College: For the class of 2021, 51 percent of students scored between 750 and 800 for evidence-based reading and writing; 31 percent scored between 690 and 740; 15 percent scored between 630 and 680; 3 percent scored below 630 (from the Williams class of 2021 profile) As this limited data shows, a strong application will usually have SAT Subject Test scores in the 700s. Realize, however, that all elite schools have a holistic admissions process, and significant strengths in other areas can make up for a less-than-ideal test score. For course credit and placement in Literature, the SAT Literature Subject Test is rarely used. Some colleges will use it to assess the college-readiness of home-schooled students, but for course placement AP exams are used far more frequently. Data source for the chart below: the College Board website. Literature SAT Subject Test Scores and Percentiles SAT Literature SubjectTest Score Percentile 800 99 780 96 760 93 740 88 720 81 700 75 680 68 660 61 640 54 620 49 600 42 580 38 560 33 540 29 520 25 500 23 480 19 460 16 440 14 420 10 400 7 In general, Advanced Placement exams are better than SAT subject tests in assessing an applicants college readiness in an academic discipline. Nevertheless, both AP and SAT can play a positive role in your application process by demonstrating your mastery of a subject area. While an A in a high school literature class can mean something different at different high schools, a 750 on the literature SAT subject test convincingly shows that an applicant has mastered a range of ideas and concepts related to literary study.
Wednesday, May 6, 2020
Administration of Justice Rich vs. Poor Free Essays
People with money have a greater chance to win or get lower sentences compared to poor families. In todayââ¬â¢s society we see all kinds of unfair cases coming in and out if the courtroom. People who have enough money to go hire a top of the line lawyer to protect them from being accounted guilty. We will write a custom essay sample on Administration of Justice: Rich vs. Poor or any similar topic only for you Order Now All the while in the poor community people struggle to survive just to pay their rent, and when they commit a crime itââ¬â¢s hard for them to afford a top of the line lawyers. Every day you turn on the TV or the radio and hear about these celebrities that constantly get in trouble for drugs, guns, and fighting but yet when the judge sentences them itââ¬â¢s like they get a smack on the hand or receive the minimum sentence available. This even happens in a reoccurring basis with the same people in and out like a revolving door. The lower income communities get arrested and go to court and unless they receive a plea bargain they usually are looking at the maximum amount of sentencing when it comes to chronic offenders. Even those low income first time offenders can be hit hard when it comes to sentencing unless the crime committed isnââ¬â¢t at high risk. I will discuss some celebrity cases as well as regular civilian cases in todayââ¬â¢s courts. Celebrity Lindsey Lohan is considered a repeat offender in and out if the court room for cocaine possession. On July 6th 2010 she was sentenced to 90 days in jail and remained free until July 20th 2010 when she had arrived at the Beverley Hills court house to turn herself in to start serving her sentence. Upon release she had to also serve a 90 day impatient rehabilitation sentence due to violating her probation from a prior DUI case. According to the spokes person Steve Whitmore of the Sheriffââ¬â¢s Department stated she would only serve 23 days behind bars since it was a non-violent crime. Regularly the sentence for Recidivist is if a misdemeanor is one year it goes up to two years, if it is a felony can be increased by four additional years. Convicted ââ¬Å"crackâ⬠offenders are usually African Americans and ââ¬Å"cocaineâ⬠offenders are usually white. The disparity in punishment evoked images of low-income blacks sitting in jail for crack longer than affluent whites caught with the same amount of cocaine, but in powder form. By the crack offenders being mostly poor black people they been receiving higher sentencing and a unfair trial, seeing as white people get caught with cocaine most of the time the sentencing isnââ¬â¢t as harsh due to their color of skin and if they come from wealth. I Washington as of the 1st of November, 2007 they are passing a federal rule that will shorten time for new crack offenders regardless of race, to be able to decrease the thought of racial issues. Of the nearly 20,000 federal prisoners whose sentences could be reduced, 86 percent are black and 6 percent are white, according to the commission. Speaking with a Chronic offender Benito Garibay who I interviewed he stated that while being charged for drug cases he always received the maximum sentence that was set against him in disregard to his home life. He also stated he had two prior drug cases before catching the third one were they charged him with a class X felony, which is a sentence of a minimum of six years in a state penitentiary and a maximum of thirty years. He was sentenced to the minimum and involved himself in classes for his diploma as well as a work study to help reduce his sentence for what is called ââ¬Å"good timeâ⬠. Weapon cases on the other hand are the same issue depending on the personââ¬â¢s race and economical status. For instance I have two examples of celebrities caught with guns and served less time than the average offender, even though they are black males, they both still have the money for good lawyers and in a political issue people can assume they also have paid off officials revolving around the case to receive lighter sentences. In the case of T. I. a well known rapper whose real name is Clifford Harris Jr, was caught with numerous types of guns in his home ranging from hand guns to semi-automatic weapons in October 2007. He was arrested and posted to bail to be released until hearings took place which ended up being a very long process. His suppression hearing was scheduled for February 19, 2008 when the performer admitted guilt to possession of U. S. federal weapon charges. He was sentenced to serve one year and one day in prison, one year of house arrest, and 1,500 hours of community service. He also had to pay $100,300 for the federal weapons charges. The performer went in to serve his sentence May 26, 2009 and was released on March 26, 2009. After being released the performer already has new charges brought up against him for the possession of methamphetamines. With this case coming soon after being released from prison on the weapon charges, the media speaks about how harsh the charges may be this time. I think thatââ¬â¢s just the media assumption and my assumption would be looked at differently and he will get off easy yet again. Dwayne Carter also known as Lil Wayne a very successful rapper ran into trouble on the streets of Manhattan in 2007. The police had pulled over the tour bus after the performer was smoking marijuana at a concert he did at the Beacon Theatre. During the search the police found and seized a . 40caliber loaded semi-automatic gun. During Wayneââ¬â¢s initial appearance he stated he was innocent and the gun did not belong to him. Trial was then set for January 20th were a controversial DNA profiling technique had tied the performer to the weapon. From January to February 2010 the performer was scheduled for his possible sentence of 8 to 10 months. Just like T. I. he is also scheduled to go to trial in Arizona on felony drug possession and weapons charges, stemming from a January 2008 arrest at a U. S. Border Patrol checkpoint. Interstate 9 is known for illegal drug trafficking and illegal aliens trying to get over. During the border patrolââ¬â¢s common evenings the performerââ¬â¢s tour bus was pulled over and searched when, they found three guns, $22,000 in cash, and drugs. The authorities discovered 105 grams of marijuana, 29 grams of cocaine, 41 grams of ecstasy and various drug paraphernalia. While we are currently unaware of the sentence he is looking at for this case in Arizona Lil Wayne must first get past his sentence being held in Rikerââ¬â¢s Island Penitentiary where he was placed on close surveillance due to a rumor of himself trying to commit suicide. The scheduled release date was November 11th but ended up getting out Thursday morning on November 4th 2010. This goes to show that higher class people and celebrities get off more easier then poor families who have nothing. Just because someone or someoneââ¬â¢s family member are drug addicts doesnââ¬â¢t mean they donââ¬â¢t deserve just as much as a fair trial just like someone that can afford the great lawyer or have connections with in the politics of the court house. How to cite Administration of Justice: Rich vs. Poor, Papers
Thursday, April 30, 2020
Lost Foam Casting Essay Example
Lost Foam Casting Paper LOST FOAM CASTING ABSTRACT: The Report presents some theoretical and practical aspects regarding the casting of alloys in lost foam moulds. The stages of the procedure, the economic benefits and several ecological aspects are synthetically presented. KEY WORDS: casting, alloys, lost foam process, Expanded polystyrene Introduction The lost foam casting process offers several advantages over conventional sand casting processes, such as simplified production techniques and reduced environmental waste due to binder system emissions and sand disposal. The process is well-suited for castings with complex geometries, tight tolerances, and smooth as-cast surface finish requirements. When the castings are designed to fully exploit these advantages, cleaning and machining times are dramatically reduced if not completely eliminated. Therefore, the lost foam casting process is viewed as a value-added process rather than a substitute for sand casting. Lost foam castings are produced by pouring molten metal into a foam pattern contained in a flask filled with loose sand that is compacted through vibration. Generally speaking, a foam pattern is coated with a refractory slurry and dried before being placed in the flask and surrounded by large grain fineness sand. The foam pattern degrades immediately after molten metal is introduced, leaving a casting that duplicates all features of the foam pattern. We will write a custom essay sample on Lost Foam Casting specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Lost Foam Casting specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Lost Foam Casting specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The degradation products are vented into the loose sand. In lost foam casting process, mold filling, thermal transport, and solidification are strongly influenced by the foam pattern degradation. There are three phenomena which are inherent in lost foam casting process: slow molten metal flow, reducing atmosphere, and degradation products. The first and second phenomena help reduce oxides or slag defects. The last one, however, may become casting defects if they remain in the cast parts. To improve lost foam casting design, it is ssential to understand the interactions between the foam pattern and molten metal as well as the displacement of degradation products. History The first patent for an evaporative-pattern casting process was filed in April 1956, by H. F. Shroyer. He patented the use of foam patterns embedded in traditional green sand for metal casting. In his patent, a pattern was machined from a block of expanded polystyrene (EPS), and supported by bonded sand during pouring . This process is now known as the full mold process. In 1964, M. C. Flemmings used unbonded sand for the process. The first North American foundry to use evaporative-pattern casting was the Robinson Foundry at Alexander City, Alabama. General motors first product using these processes was the 4. 3L, V-6 diesel cylinder head, which were made in 1981 at Massena, New York. A study found in 1997 that evaporative-pattern casting processes accounted for approximately 140,000 tons of aluminum casting in the United States. The same survey forecast that evaporative-pattern casting processes would account for 29% of the aluminum, and 14% of the ferrous casting markets in the near future. Definition Definition| A casting process whereby the pettern is made of polystyrene foam and is vaporized when the mold is fill with molten metal| Lost form consist of first making a foam pattern having the geometry of the desire finish metal| Expanded polystyrene casting use a mold or sand park around a polystyrene pattern that vapourizes when the molten metal is poured into the mold| Evaporating pattern casting (lost foam) : this process is also know as lost pattern casting under a trade name ââ¬Å"full mold processâ⬠, it use a polystyrene pattern which evaporate upon contact with molten metal to form a cavity for the casting| Lost foam casting, where the mould cavity is filled with polystyrene foam (the ââ¬Ëfull mouldââ¬â¢ process) , is a special case. | What is ââ¬Å"Lost Foamâ⬠? The Lost Foam casting process originated in 1958 when H. F. Shroyer was granted a patent for a cavity-less casting method, using a polystyrene foam pattern embedded in traditional green sand. The polystyrene foam pattern left in the sand is decomposed by the poured molten metal. The metal replaces the foam pattern, exactly duplicating all of the features of the original pattern. Like other investment casting methods, this requires that a pattern be produced for every casting poured because it is evaporated (ââ¬Å"lostâ⬠) in the process. Schematic of lost for casting Process The essential steps of the lost foam casting procedure are: 1) The execution of patterns, 2) Execution of moulds 3) casting the alloy. Execution of Patterns: A pattern is made fromà polystyrene foam (Expanded Polysterene), which can be done many different. What is Expanded Polystyrene? Expanded Polystyrene in its broadest sense is a rigid cellular plastic which is found in a multitude of shapes and applications. Raw Material Manufacturing: Expanded polystyrene (EPS) is the most commonly used foam pattern, it can be produced by bead pre-expansion into polystyrene (PS) beads that are ready for moulding. PS precursors are formed from ethyl benzene through an aluminum catalyst with benzene and ethylene obtained from crude oil and natural gas [Shivkumar, 1994]. Ethyl benzene is then converted to styrene at high temperature with nitrogen gas and iron catalysts. It forms polystyrene when exposed to a peroxide catalyst and polymerized in a water solution [Goria et al. , 1986]. These unexpanded beads have a density of 600 g/l (38 pounds per cubic feet (pcf)) and they are expanded 20~50 times with heat at 100 oC until the desired density is reached [Kanicki, 1985]. Polystyrene (PS) MOLECULAR FORMULA: The C=C double bond in each monomer is transformed into a C-C single bond in the polymer. | Properties: ease of forming, clarity, low heat transfer, good thermal insulation. Density: 1. 03-1. 06 g/ccStatistic: In 1999 PS usage as a plastic bottle resin was essentially nil. | Description: Polystyrene can be made into rigid or foamed products. It has a relatively low melting point. Packaging applications: Plates, cups, cutlery, meat trays, egg cartons, carry-out containers, aspirin bottles, compact disc jackets Recycled products: Thermal insulation, light switch plates, egg cartons, vents, rulers, foam packing, carry-out containers Raw Material Manufacturing: Expanded Polystyrene (foam)à is obtained from expandable polystyrene (beads), which is a rigid cellular plastic which contains an expansion agent. Expandable polystyrene is therefore obtained from oil as can be seen from the diagram. The EPS Manufacturing Process is inextricably linked with the process described in the last section, which brought us from the oil well to expandable polystyrene, now we will see what happens in the transformation process that leads us to Expanded Polystyrene foam parts. We have seen that the raw material is obtained through a chemical process. The next process involves the use of physics and the conversion process is carried out in three stages. 1st stage à PRE-EXPANSION: The raw material (beads)à is heated in special machines called pre-expanders with steam at temperatures of approximately 215-f. The density of the material falls from 40lbs/cu ft to values of usually between 1 ~ 2lbs/cu ft. During the process of pre-expansion the raw materials hard beads turns into cellular (foam) plastic beads with small closed cells that hold air in their interior. 2nd stage à INTERMEDIATE MATURING AND STABILIZATION: On cooling, the recently expanded particles form a vacuum in their interior and this must be compensated for by air diffusion. This is how the beads achieve greater mechanical elasticity and improve expansion capacity, something very useful in the following transformation stage. This process is carried out during the materials intermediate maturing in aerated silos or mesh bags. The beads are dried at the same time. 3rd stage à EXPANSION AND FINAL MOLDING: During this stage the stabilized pre-expanded beads are transported to molds where they are again subjected to steam so that the beads bind together. In this way large blocks are obtained block molding à (that are later sectioned to the required shape like boards, panels, cylinders etc. ) or products in their final finished shape shape molding. Execution of moulds and casting alloy The basic steps to the process include: A foam pattern and gating system are made using a foam molding press * The foam pattern and the gating system are glued together to form a cluster of patterns * The cluster is coated with a permeable refractory coating and dried unde r controlled conditions * The dried, coated cluster is invested in a foundry flask with loose, unbonded sand that is vibrated to provide tight compaction * The molten metal is poured on to the top of the gating system which directs the metal throughout the cluster and replaces the foam gating and patterns * The remaining operations such as, shakeout, cut-off, grinding, heat treat, etc. are straightforward and similar to other casting processes. The series and major steps in lost foam casting (LFC) What metals can be poured in the Lost Foam process? Generally, all ferrous and non-ferrous materials can be successfully cast using the Lost Foam process. Because the foam pattern and gating system must be decomposed to produce a casting, metal pouring temperatures above 1000à °F are usually required. Lower temperature metals can be poured, but part size is limited. In addition, very low carbon ferrous castings will require special processing. What size range of parts can be produced by the Lost Foam process? Lost Foam castings can be produced in most all metals from a fraction of a pound up to thousands of pounds. Slightly more advanced techniques are used for very large castings. What type of tooling is required and at what cost? Typically, tooling is composed of a split-cavity machined aluminum die that is the negative mold from which the foam pattern is produced. The tooling is highly specialized and must be constructed by experienced tooling manufacturers familiar with the requirements of the foam molders and foundries. Most tooling for Lost Foam patterns will compare favorably with permanent and die cast tooling. Prototype and simple tools may be in the $3000-5000 range while high-end tooling for complex or very large parts can be in the several hundred thousand dollar range. As a result of the materials used and the process stresses, Lost Foam tools can be expected to have 3 to 4 times the cycle life of permanent mold or die casting tools. What lead times can be expected when ordering a Lost Foam casting? As with all processes, lead times vary greatly depending on part complexity. Generally, 8 to 16 weeks is typical for completed tooling and first castings produced. After casting approval, 6 to 12 weeks is typical for production run startup. Rapid prototyping methods can produce castings in as little as 2 to 3 weeks. What size range of parts can be produced by the Lost Foam process? Lost Foam castings can be produced in most all metals from a fraction of a pound up to thousands of pounds. Slightly more advanced echniques are used for very large castings. What is the cost of using the Lost Foam process? Lost Foam castings are generally more expensive than forged parts, or parts made by other casting processes. The value inherent in the Lost Foam process v ersus other processes is seen in tighter tolerances, weight reduction and as-cast features which all results in less machining and cleanup time. Many castings that require milling, turning, drilling and grinding can be made in the Lost Foam process with only . 020â⬠. 030â⬠of machine stock. It is imperative that the features to be cast are discussed by all parties to determine the net finished product cost. What quantities need to be made to make the Lost Foam process practical? The answer, simply, is not as many as you would think. Tooling amortization is a key factor in this determination. Potential overall savings for your application will aid in your decision. Generally, 500-1000 pieces per year is the minimum production run to be economical. Prototyping runs, however, may be as few as 3-5 pieces for Fabricated Foam patterns or 20-100 pieces for Quick-Cut CNC machined aluminum tooling. Application Lost foam castingà is used mostly for automotive applications. Cast iron, aluminum alloys, steels, nickel and in some cases stainless steel and copper alloys are cast in this process. The flexibility of LFC is useful in making complicated casting assemblies for automotive and other metal cast like cylinder heads, weldments, pump housing, Manifolds for automobile, machine bases, automobile-body-dies, brake component. etc. This simple and inexpensive method is used in hobby foundry work. Examples of product produce from lost foam casting http://www. glmmarine. com/ManifoldArticle. html Superior Marine Manifolds Agricultural Equipment Part / Farm Machinery Part Product Description Detail Feature: Product Name: Agricultural equipment part / Farm machinery partà Materials: Grey iron, Ductile Iron, High Chrome iron, resistent ironcarbon steels, alloy steels, stainless steels, High Manganese steelà Items: FOB NingBo or Shanghai Place of Origin: Ningbo, China Software for specification drawings: PDF, Auto CAD, Solid work, JPG, ProEà Main production equipments: Wax injection, CNC-machine, machine-center, Heat treatment Furnace lost foam casting for yacht gas piping Specifications 1). lost foam casting 2). reliable product quality 3). on time delivery 4). excellent after-sale service 5). 3D design It is designed for the yacht or the ships gas exhaust piping. Materials: pig iron 250 Surface treatment: galvanizing, and spray-paint Weight: 19. 5 KG Color: black Process: lost foam casting Dimensions:360mm*167mm*102mm Certificate: ISO9001:2000 Advantages * Foam is to carve glue and manipulate Can be used for precision castings of ferrous and non-ferrous metals of any size. * Fewer steps are involved in lost foam casting compared to sand casting. * Core making is eliminated. * Binders or other additives and related mixing processes are eliminated. * High dimensional accuracy can be achieved and thin sections can be cast (i. e. 3 mm). * There is lower capital investment. * The flasks used are less expensive and easier to use because they are in one piece. * The need for skilled labor is reduced. * Multiple castings can be combined in one mould to increase pouring efficiency. * Lower operating costs can be achieved for appropriate castings. Complex castings, particularly internal sections, which require high dimensional accuracy and have thin sections, can be produced very cost effectively in comparison with to conventional sand moulding processes. * Fettling and machining is minimized due to high dimensional accuracy and the absence of parting lines or core fins. * The shakeout process is simplified and does not require the heavy machinery required for bonded sand systems. * High levels of sand reuse are possible. As little as 1-2% of the sand is lost as a result of spills. Periodically a portion of sand may need to be removed or reclaimed to avoid the build-up of styrene. * Complex components can be formed where other casting processes would require multiple components to be assembled. Excellent dimensional tolerances for precision casting. * Lower production cost than traditional Green Sand casting. * Castings can be made from 1 pound up to thousands of pounds with no size limitations. * Lost Foam is an environmental ly friendly process. * The sand is un-bonded and can be recovered and re-used at a low cost. * There is lower capital investment. Disadvantages * pattern costs can be high for low volume application * patterns are easily damaged or distorted due to their low strength. If a die is used to create the patterns there is a large initial cost * The pattern coating process is time-consuming, and pattern handling requires great care. Good process control is required as a scrapped casting means replacement not only of the mold but the pattern as well. What type of tooling is required and at what cost? Typically, tooling is composed of a split-cavity machined aluminum die that is the negative mold from which the foam pattern is produced. The tooling is highly specialized and must be constructed by experienced tooling manufacturers familiar with the requirements of the foam molders and foundries. Most tooling for Lost Foam patterns will compare favorably with permanent and die cast tooling. Pr ototype and simple tools may be in the $3000-5000 range while high-end tooling for complex or very large parts can be in the several hundred thousand dollar range. As a result of the materials used and the process stresses, Lost Foam tools can be expected to have 3 to 4 times the cycle life of permanent mold or die casting tools. What ââ¬Å"as-castâ⬠tolerances can be expected? Typically, a linear tolerance of +/-. 005 inches/inch is standard for the Lost Foam process. This tolerance will vary depending on part size, complexity and geometry. Subsequent straightening or coining procedures will often enable even tighter tolerances to be held on critical dimensions. A targeted effort between the foam pattern producer, the casting producer and the casting user will often result in a Lost Foam casting that substantially reduces or completely eliminates previous machining requirements. Diameter Tolerance 0-1 in. [ or -]0. 007 in. 1-3 in. [ or -]0. 15 in. 3-6 in. [ or -]0. 025 in. In the case of diameters split by glue lines, 0. 005-0. 010 in. should be added dependent on foam size. Linear Tolerance 0-2 in. [ or -]0. 005-0. 10 in. 2-5 in. [ or - ]0. 010-0. 20 in. 0-5 in. with glue lines [ or -]0. 025-0. 035 in. Flatness Tolerance Area 3 x 3 in. [ or -]0. 007 in. Area 10 x 10 in. [ or -]0. 015-0. 020 in. More than 10 in. [ or -]0. 030-0. 050 in. Flatness can be affected by the foam, foam geometry, molding cycle control and foam removal. True Position Tolerance 0-2 in. 0. 025 in. 2-4 in. 0. 030 in. 4-10 in. 0. 030-0. 60 in. 10 in. 0. 080 in. Limitations 1. For low volume applications, the pattern costs are relatively high, therefore in order to increase the substantial economic benefits and decrease the pattern costs, only bulk quantities should be produced. 2. Due to their low strength, the patterns are very easily damaged and/or distorted. 3. There is a very high initial cost if a die is used to create the patterns. 4. The coating process is very time consuming as the pattern handling requires great care. Design considerations: Ensure that there is adequate material: Insufficient material usually leads to incomplete castings in the manufacturing of parts. It is important to calculate the volume of all areas f the casting while also accounting for shrinkage. Consider the Superheat: Superheat is the temperature difference between the metal at pouring and freezing. An increase in the superheat can increase the fluidity of the material for the casting, which can assist with its flow into the mold. Insulate Risers: The riser should be the last to solidify because it is the reservoir of molten material for the casting. Therefore insulating the top will greatly reduce cooling in the risers from the steep temperature gradient between the liquid metal of the casting, and the room temperature air. Consider V/A Ratios: V/A ratio represents the volume to surface area ratio. In casting, sections with low volume to surface area will solidify faster than sections with higher volume to surface area. It is therefore important to consider the V/A ratios in order to avoid premature solidification of the casting and the formation of vacancies. Heat Masses: Sections of the casting with low V/A ratios should be located further away from the risers as this will ensure a smooth solidification of the casting. It is important to avoid large heat masses in locations distant to risers. Sections of the Casting: A heavy section should not be fed through a lighter one. In the manufacturing process, the flow of material is very important. Prevent Planes of Weakness: After the solidifications of castings, columnar grain structures pointing toward the center develop in the material. This causes the sharp corners in the casting to develop a plane of weakness. This is prevented by rounding the edges of sharp corners. Reduce Tubulence: Turbulence is bad because it traps gases in the casting material and causes mold erosion. It can be reduced by the design of a gating system that promotes a more laminar flow of the liquid metal. FUTURE EPF can safely be incinerated and will yield only carbon dioxide and water if the procedure is handled correctly, but the trend has been to recycle it wherever possible. EPF can be recycled intoà concrete,à egg cartons, office products, foam insulation, and garbage cans. Unfortunately, only one percent of the 11 billion kilograms of EPF thrown away each year is being recycled. The National Polystyrene Recycling Company, which consists of seven major corporations, including Amoco, Dow, and Mobil, plans to increase this to 25 percent by 1995 by focusing on big users of EPFââ¬âfast food outlets and college dining establishments. Since the Montreal Protocol of 1988, new research has focused on ways to reduce CFC use, and on developing alternative blowing agents that will not harm the ozone layer. Recent developments include a process that uses pressurized carbon dioxide to produce smaller, more uniform cells. These in turn provide a foam that is stronger and smoother than earlier foams. All this will bring us an un-imaginable shape that can be use for EPF pattern which will aid quality, best and control of casting. STRATEGY EMPLOYED TO THE IMPROVEMENT OF LOST FOAM CASTING CAPABILITY 1. The major strategy employed is the partnership of governments, universities and industries in research and development of metal casting in general and cost of research is shared. Examples are U. S. Department of Energy and metal casting industry industries of the future (IOF), University of Alabama-Birmingham and over 30 universities and industry partners. This strategy has significantly improved the use of LFC in the past years. Emphasis is based on universities research with strong industry participation. The direct results of LFC researches are quickly applied by these positioned partner industries and results from the various applications are evaluated and analyzed. 2. Another strategy used is introducing hundreds of students to metal casting industries were they are well trained and becomes more innovative bringing latest technical knowledge and processes. this has tremendously improve state-of-the-heart technology in improving LFC in the past years. 3. Material(s) selection requires a specific type of manufacturing process(s) and different type(s) of casting techniques. The casting materials specific heat as well as that of the mold material will be influential in controlling the thermal gradients in the system. e. g. meltsà fluidity and flow. A material high heat of fusion will take longer to solidify and may improve flow characteristics within the casting. 4. Gases being expelled by the material during solidification can be eliminated by a proper venting system in the mold. This can be planned out during the manufacturing design phase of the casting process. WAYS TO IMPROVE LOST FOAM CASTING 1. Development of computational fluid dynamics tool for modeling the blowing and steaming of expandable polystyrene (EPS) pattern for lost foam casting(mathematical tool). it allows analytical approach to systematically design EPS pattern molds that produces higher quality pattern with reduced lead-time and expense. http://www. arena-flow. com 2. Reduction of porosity and fold defects has improve production efficiency, mechanical properties and marketability of lost foam casting. 3. The combination of LFC with 3DP (three dimensional printing) to eliminate machining of mold contours and manual process of drilling and finishing steam holes, i. e. repeatedly printing thin layers of bonding materials on a thin layer of powder to build up a tool(mould) shape from computer-aided design(CAD) 4. Complex and detailed passages and other features are cast directly e. g. oil galleries, crank case ventilation channels, oil drain back passage, coolant passage etc are cast directly into cylinder blocks 5. The use of Flow Particle Image Analyzer to analyzed the wet slurry (prior to its application on the foam pattern) by measuring ceramic particle size and shape. 6. Single and multiple air gauge developed for rapid determination of pattern dimension 7. Compaction gauges were developed to measure sand density in cavities during pattern compaction 8. Distortion gauge to determine when and under what conditions pattern distortion occurs during compaction 9. Developed procedures to measure liquid absorption characteristics of liquid pattern pyrolisis 10. Developed instruments to measure gas permeability 11. X-ray radiography was developed to measure time of fill and also to inspect casting qualities and defects in LFC. Material selection is another way to improve the capability for example: * Certain materials react, (particularly in a molten state), a certain way with other materials they may encounter during the casting process. This should always be a consideration. For example liquid aluminum will react readily with iron. Iron ladles and surfaces contacting the molten aluminum can be covered with a spray-on ceramic coating to prevent this. * When selecting a specific type of manufacturing process, remember that certain materials are more applicable to different types of casting techniques than others. * The casting materials specific heat will as well as that of the mold material will be influential in controlling the thermal gradients in the system. Different materials will factor heavily on the meltsà fluidity * A material high heat of fusion will take longer to solidify and may improve flow characteristics within the casting * When manufacturing a casting an alloy that freezes over a tempe rature range problems may occur due to the solid phase interfering with the liquid phase -both of which will be present within the temperature range. To help reduce this problem an alloy with a shorter solidification temperature range may be selected to manufacture the casting with. Or select a mold material with a high thermal conductivity, which could reduce the time spent in this range by increasing the cooling rate. Conclusion using the method of casting by lost foam patterns, we can obtain pieces for industry and ornamental elements / applied art, with complex layouts and different sizes, without the danger of offsetting * using the method of casting by lost foam patterns we can obtain pieces with weights between a few kilograms and tenths of tones, with wallââ¬â¢s width between 1 mm and 50 mm, made of different alloys: ferrous (cast iron and steel) and non ferrous (basic alloys of Al, Cu, Mg); * using the method of casting by lost foam patterns we can obtain pieces with a l ow consumption of materials and energy; * The method of casting by lost foam patterns can be used also for: structural changes and superficial alloying of the pieces; obtaining composite materials with powders insertion and the guidance of hardening by using some active powders, internal coolers or exterior coatings. The gases resulted from the thermal destruction of the polystyrene are toxic for the human being and can generate negative effects on the environment, aspect which imposes the obligation of maintaining under control both the evacuation in the working environment as well as the evacuation in the atmosphere. REFERENCES Design for manufacturability handbook à By James G. Bralla , McGraw-Hill Professional, 1999 Technology ; Engineering Energy research at DOE, was it worth it? : energy efficiency and fossil energy research 1978 to 2000, National Academies Press, 2001 Business ; Economics Fundamentals of Modern Manufacturing: Materials, Processes, and Systemsà By Mikell P. Groover, John Wiley and Sons, 2010 Technology ; Engineering A textbook of manufacturing technology: (manufacturing processes) à By R. K. Rajput, Firewall Media, 2008 Technology ; Engineering John Campbell, Butterworth-Heinemann, 2003 à Technology ; Engineeringà http://www. technalysis. com/lost_foam_casting. aspx http://civil-engg-world. blogspot. com/2011/02/polystyrene-ps. html http://www. achfoam. com/Lost-Foam-Casting-Process. aspx http://www. madehow. com/Volume-1/Expanded-Polystyrene-Foam-EPF. html http://www. alibaba. com/product-gs/411205184/lost_foam_casting_for_yacht_gas. html? newId=411205184;pn=1;pt=10;t=12;cids= http://nb-pft. en. made-in-china. com/product/HMZxTjlJqEDn/China-Agricultural-Equipment-Part-Farm-Machinery-Part. html http://www. nyserda. org/programs/industry/CaseStudies/lost%20foam. pdf
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