Spy Planes Essay Research Paper WHIDBEY ISLAND free essay sample

Spy Planes Essay, Research Paper WHIDBEY ISLAND NAVAL AIR STATION, Wash. ( Reuters ) # 8211 ; The 24 Navy crew members of a U.S. undercover agent plane detained in China for 11 yearss arrived back at their place base to a hero # 8217 ; s welcome from 1000s of relations and protagonists. About 5,000 people, many beckoning # 8220 ; Welcome Home # 8221 ; postings, American flags and xanthous threads, gathered at the Naval air base on Washington province # 8217 ; s Whidbey Island, North of Seattle, as the crew stepped off the military plane that flew them place after a debriefing in Hawaii. Politicians and top military brass every bit good as relations, friends and co-workers gathered Saturday on the tarmac outside a airdock bedecked with flags and balloons for the homecoming ceremonial where a ruddy rug was rolled out for the crew. The crew members # 8212 ; 21 work forces and three adult females # 8212 ; hugged their relations, shook custodies with very important persons and so marched past multitudes of supporters to a response where politicians and high-level Navy officers hailed their # 8220 ; model # 8221 ; behaviour during their detainment in China. We will write a custom essay sample on Spy Planes Essay Research Paper WHIDBEY ISLAND or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page # 8220 ; Your actions made us all proud to be Americans, # 8221 ; said Rear Adm. Michael Holmes, who commands the Navy # 8217 ; s Pacific patrol and reconnaissance force. Home For Easter Arriving place a twenty-four hours before the Christian Easter vacation, several of the crew members thanked God for their safe return place and described their fright as their EP-3 surveillance plane, severely damaged in a hit with a Chinese F-8 combatant, made an exigency set downing on China # 8217 ; s Hainan Island. # 8220 ; It was chilling. At the clip, I thought hey, I # 8217 ; m 20 old ages old, I had a good life, # 8221 ; said Cryptologic Technician Jeremy Crandall. # 8220 ; But the crew was tight and everybody looked out for each other. # 8221 ; Armed Chinese soldiers rapidly made it clear to the crew that they had to go forth the plane, though one crew member said their actions were # 8220 ; non really aggressive. # 8221 ; The Americans calmly ran through a checklist, disenabling the plane # 8217 ; s advanced electronic hearing devices and destructing sensitive informations before the Chinese boarded the plane. At a imperativeness conference after the response, the crew described their crippled aircraft # 8217 ; s descent and a non really comfy stay in Chinese detention. Asked what was the first thing the Chinese said to them, Lt. Patrick Honeck quipped: # 8220 ; It wasn # 8217 ; T in English. # 8221 ; Chinese functionaries repeatedly demanded an apology from the crew members, as they had from the U.S. authorities, for doing the accident and for set downing in Chinese ter ritory without permission. However after a U.S. embassy functionary told them that President Bush ( intelligence # 8211 ; net sites ) had refused to take the incrimination for the accident, the crew repeated his words to the Chinese. Bush finally expressed sorrow and sorrow at the decease of the Chinese combatant pilot whose plane struck the bottom of the slow-moving U.S. undercover agent plane. The U.S. crew said they had radioed repeatedly to bespeak an exigency set downing on Hainan. Honeck described the daze he and his comrades felt merely after the hit, but said the group subsequently pulled together and made the best of the state of affairs. # 8220 ; Our intervention was just. We were fed reasonably good, # 8221 ; he said. Photographs Reuters Photo Rice And Coca-Cola Other crew members said their rations were limited to rice and bread, with small meat or veggies, though the Chinese did provide them with Coca-Cola. # 8220 ; Basically they fed us rice, # 8221 ; said Aviation Machinist # 8217 ; s Mate Wendy Westbrook. Possibly the most romantic minute of the twenty-four hours was provided by Cryptologic Technician Josef Edmunds, who introduced his bride-to-be, Sandra White of Fort Worth, Texas. Edmunds proposed to White by telephone Friday, after the crew left Hainan for their initial return to U.S. dirt in Guam. # 8220 ; I wanted to wait for the perfect minute, but sometimes the perfect minute neer comes, # 8221 ; Edmunds said. Pilot The Biggest Hero The loudest congratulations went to Lt. Shane Osborn, the pilot and commanding officer of the mission, who landed the plane despite extended harm, salvaging the lives of the crew. Navy functionaries rejected unfavorable judgment of Osborn # 8217 ; s speedy determination to seek to set down, alternatively of bailing out or ditching the plane in the South China Sea to maintain its ultra-secret eavesdropping equipment from falling into Chinese custodies. # 8220 ; Mr. Osborn made the right determination, and I recognition him with salvaging the lives of his crew, # 8221 ; Holmes said. Earlier Saturday Osborn rejected official Chinese claims that the U.S. plane caused the clang. # 8220 ; I am here to state you we did it right, # 8221 ; Osborn told newsmans in Hawaii before get oning the flight for Whidbey Island. # 8220 ; There are no apologies necessary on our part. # 8221 ; Many in the crowd had damp eyes amid the chauvinistic and emotional images of reunited households and the show of support was non lost on the geting crew members. # 8220 ; I # 8217 ; ve neer felt so proud to be an American in my whole life, # 8221 ; said Lt. Jeffery Vignery.

Adolescent Obesity essays

Adolescent Obesity essays The adolescent years are a time when body image is crucial and peers can be painfully critical (Morrill, Leach, Shreeve, Obesity has only recently been classified as an eating disorder. Previously the label obese was simply for labeling sake, but clearly serious implications are involved with the mental and physical health of the individual and more needs to be done. Currently, the amount of obese people is still on the rise and about 23% of the North American population is clinically obese (Gullotta, Adams The nature versus nature debate exists in the study of ...

Nacroterrorism Research Paper Example | Topics and Well Written Essays - 750 words

Nacroterrorism - Research Paper Example One of the reasons for increased narco-terrorism is that mergers between terrorists and drug traffickers benefit both sides. Terrorists enable drug traffickers to access military skills, clandestine groups, and weapons. Since terrorists mostly operate vast amount of territories, drug traffickers benefit by freely moving their assets. On the other hand, drug traffickers benefit terrorist by being a source of revenue and expertise in an illegal transfer. Additionally, most terrorist organizations believe that flooding their enemies with drugs can weaken them. The terrorists believe that after intoxicating their enemies with drugs, they can go ahead and do what they wish. Hence, they need drug dealers to facilitate their operations (Beers and Taylor 4). Another reason that has fueled narcoterrorism is that terrorists and drug traffickers more or less have similar methods of operations. Both groups employ the services of corrupt officials for mutual benefits. Some of the services include access to fraudulent documents. Both sides increasingly depend on the structures of cells to achieve their respective goals while enhancing security (Beers and Taylor 5). Members of compartmentalized cells carry daily activities as directed by a centralized strong leadership. Additionally, they conceal fund-raising and profits using informal transfer systems, smuggling bulk cash, opening multiple bank accounts, and bribing front organizations. Countries that have poorly regulated banking systems make it easier for drug traffickers and terrorists to use online transfers and open accounts that do not request disclosure of owners. Furthermore, both groups conceal their communication channels and code languages. Moreover, nations use same techniques and equipment to combat drug trafficking groups and terrorist organizations. In the past, state sponsors funded terrorist organizations that in turn helped them to secure

Economic devlopment in tanzania and oman Essay Example | Topics and Well Written Essays - 1750 words

Economic devlopment in tanzania and oman - Essay Example On the other hand, Soheir Mohamed Hegazy writes about the economic development initiatives that Oman has taken over time. She relates the advancements in the economy of the nation to its cultural set-up while proposing the needfulness for the betterment of the tourism infrastructure. Therefore, this work will present an analysis of two articles; Tanzania in Transition: from Nyerere to Mkapa by Wangwe (2010) and Conservation of Omani archaeological sites, Haratal Bilad by Hegazy (2014). The analysis will, therefore, give the background for the comparison of the historical developments of the two economic systems. Professor Samuel Wangwe is an economist and economic advisor to the government of Tanzania, as well as a policy researcher who has played a role in several organizations. He is a presiding member of the Independent Monitoring Group (IMG), a body that is responsible for supervising the partnership of the government of Tanzania and donors. The chapter, therefore, reviews the challenges and the improvements that the government has gone through altogether and provides an insight as to the suggested course of action that will suit the government of Tanzania at best. Wangwe gives a brief background information regarding the history of Tanzania economically. The government officials developed strategic reforms basing on the economic crisis that arose during the 1980s, which primarily targeted finances (Utz 2008). As the time progressed, the government and its regime sought to integrate institutional reforms into their agenda. However, this was proved to be a challenge since it required an advanced gradation of obligation from administrative figures, which was not put in place. Consequently, donors noted the limitations and shortcomings and believed that the government was not interested in its promised programs. Contrarily, the government felt that donors were intrusive in the

Perfomance standards Essay Example | Topics and Well Written Essays - 500 words

Perfomance standards - Essay Example The historical overview of Westin St. Francis was traced to as early as the 1902s which make the hotel more than 112 years to date (The Westin St. Francis, 2014). The initial step in performance evaluation is to identify the job standards based on the essential functions as expected of the position. The basic responsibilities of a doorman at a hotel include: (1) greeting the guests at arrival and even during departure through the provision of courteous, warm, and prompt service; (2) assists in handling luggage of guests from any mode of transportation to endorsement to the Bellman; (3) provides appropriate responses to the quests regarding inquiries on hotel accommodations and facilities prior to endorsement to the front desk personnel. (1) Greet the guests as soon as they arrive within the vicinity of the hotel by stating: â€Å"Welcome to The Westin St. Francis. I am . I would be glad to be of service to you.† Likewise, when the guests are to depart from the hotel, the doorman should indicate: â€Å"Thank you so much for choosing The Westin St. Francis to serve you. We look forward to being of serve to you in the near future†. This standard would improve service quality through expressly communicating to the guests how welcome they are in the hotel and how the service personnel are glad to address their accommodation requirements. As such, the warm and prompt greeting would indicate high quality of service that could provide customer satisfaction through the provision on immediate response on various inquiries and concerns. As such, the measurable and observable components of this performance standard are as follows: greeting in a warm and courteous manner (quality measure); greeting in a prompt manner with assistance to the luggage (time measure); prompt greeting at arrival and departure (time measure). (2) Assists in handling luggage of guests from any mode of transportation to endorsement to the Bellman.

The Welding Manufacturing Process Engineering Essay

The Welding Manufacturing Process Engineering Essay Welding is an attractive topic to be researched because it is used in the majority of industrial fields and manufacturing processes. The next figure shows that the shield metal arc welding process represents about 42% from the whole welding processes. The welding theory depends on the joining between two parts whether metals like aluminium, steel, copper, or cast iron or plastics like polypropylene. Welding specially is different from the normal joining where the aim of welding is to obtain a strong joint between two or more parts to be as a single part and to minimize number of parts. For example, the mechanical joints used to assemble pipe lines is limited to specific values of pressure and temperature and when those values exceed those limits, the welding takes place in the assembly process The main concept of fusion welding is the partial melting and fusion of the joint between two members and a filler metals may be used. In the arc welding process, the heat required is obtained from electrical energy. An arc is produced between the tip of the electrode and work piece to be welded, by using an AC or a DC power supply. Shield metal arc welding (SMAW) is one of the oldest, simplest, and most versatile joining processes. About 50% of all industrial and maintenance welding at present is performed by this process. The electric arc is generated by touching the tip of a coated electrode with the work piece or the sample and moving back it quickly to enough distance to maintain the arc. The heat generated melts a piece of the electrode tip, its coating and the base metal in the immediate arc area and this mixture forms the weld when it solidifies. 1.2 Aims objectives The aim or goal of the research is a broad statement of the problem which I intend to solve and what I intend to achieve. Objectives  set the realistic targets to achieve during the research and I should use best practice in project management. Objectives are derived from the aim, but are more specific and measurable. Aims: Investigate/research solutions to reduce cracks occurring in carbon steels during shield metal arc welding process Objectives: Investigate/research shield metal arc welding process in carbon steel metals Investigate/research parameters affecting shield metal arc welding process in carbon steel metals Investigate/research reasons of cracks in shield metal arc welding process in carbon steel metals and methods to reduce them. Literature review Many researches were done to investigate welding processes from many points of views and in the next pages these examples will be shown below: First example:- In the research done by G. B. JANG, H. K. KIM AND S. S. KANG, It was discovered that in the steel bridge manufacturing, there are many differences in dimensions caused by weld deformation often happen because multi-pass welding is used mainly to join thick plates. It repeatedly produced that root openings are out of tolerances at place of butt joints. Second example:- In the research done by G. B. JANG, H. K. KIM AND S. S. KANG, It was discovered that there is a new innovative method for estimating the actual cooling rate in a welded section is existed. This method is depended on applying a weighting factor to the Rosenthal* analytical solutions for thick and thin plates. The factor is calculated from the heat affected zone (HAZ) width obtained from carved sections and reflects the actual response of the plate to the heat flow condition. The formulations used in the literature of this research are depended on the assumption of thin plate and thick plate conditions while most actual conditions not real somewhere between the two extremes. Limited experimental measurements of cooling rate performed by instrumented welding presented good agreement with predicted values. The model was further used to get the peak temperature profile across the HAZ. 2.1 Methodology: As shown in the literature review, the previous two researches concentrated on the problems related to weld deformation and cooling rate.In this research the study of shield metal arc welding will be concentrated on the parameters affecting cracks appearance and the methods used and available to reduce and eliminate them. To achieve objectives, first, a study will be done to previous researches in the same field through the internet and reading different types of books to study the Methodology Block Diagram: SMAW process in carbon steels.the next step is to focus on cracks appeared and how to reduce them. Also Libraries, internet, will be used as a statement of method. The internet usage will give powerful to the research to get data now because it is fastest, cheapest, and most widely in getting data and information that needed in any section of science. Different search engine will be used as www.google.com www.yahoo.com In addition, the forums will be used to discuss results with other engineers to have learning from their experts. Libraries: from reading books you can know the theoretical part and the analysis of the welding parameters. In this study, there is no practical work but if there was a similar one in the future it must take into considerations the ensure that the final product must be safe to the environment by taking into consideration to prevent any harmful fumes. Conclusion:- After this brief proposal it can be said that this project will concentrate on three main categories:- Shield metal arc welding process in carbon steel metals Parameters affecting shield metal arc welding process in carbon steel metals Reasons of cracks in shield metal arc welding process in carbon steel metals and methods to reduce them. Also, it can be guessed that the weakness of this proposal is not mentioning many problems related to this process and a try will be done overcoming this point in the next stages of the project. This proposal takes its strength from the variety and spread of SMAW process in the industrial field as shown in the beginning of the proposal. Time Table: Completed proposal 9TH of October Initial project proposal word 3rd 11th of November Start collecting information and data 1st December-6th Start following chapter 25th December Prepare slideshow 1st January-5th Complete interim report 18th of January Work on following chapters 10th of February Project should almost be complete 10th of march Prepare for presentation 7th of may Chapter 3 Arc welding concept Arc welding is a process of the fusion welding processes which contains:- 1 Arc welding processes (non consumable electrodes) Gas tungsten arc welding Plasma arc welding Atomic hydrogen welding 2 Arc welding processes (consumable electrodes) Shielded metal arc welding Submerged arc welding Gas metal arc welding Flux cored arc welding Electro gas welding Electro slag welding 3 Electron beam welding 4 Laser beam welding The main concept of fusion welding is the partial melting and fusion of the joint between two members and a filler metals may be used. In the arc welding process, the heat required is obtained from electrical energy. An arc is produced between the tip of the electrode and work piece to be welded, by using an AC or a DC power supply. Shield metal arc welding (SMAW) is one of the oldest, simplest, and most versatile joining processes. About 50% of all industrial and maintenance welding currently is performed by this process. The electric arc is generated by touching the head or the tip of a coated electrode against the work piece and withdrawing it quickly to a distance sufficient to preserve the arc. The heat start generating from the electrode tip, its coating and the base metal in the immediate arc area and this mixture forms the weld when it solidifies. 3.2 Classification of arc welding The arc welding classified into many types used in the industrial field each one have advantages and defects different from the other type, So that the user select the required type according to the requirements and the economy aspects. In the below figure we show for the classification of arc welding which appear in the industrial (3.1) Arc welding PAW ESW MIG TIG SAW SMAW Carbon arc welding Figure 3.1 arc welding classification Chart key SMAW: shield metal arc welding SAW: submerged arc welding TIG: tungsten inert gas arc welding MIG: metal inert gas welding PAW: plasma arc welding ESW: electro slag welding The above chart list for the types of the arc welding which used in the industrial fields. Advantages of arc welding There are some characteristic for the arc welding rather than the another methods to joining metals which it represent the advantages of the arc welding listed as below 1- Strong and tight joining 2- Cost effectiveness ( arc welding have low capital and running costs) 3- Simplicity of welded structure design Figure 3.2: arc welding usage in the industry (http://64.78.42.182/sweethaven/BldgConst/Welding/lessonmain.asp?lesNum=4modNum=1) 3.2.1 Principals and definition Shield metal arc welding (SMAW) consider as process in which coalescence of metal produced by the heat which generated from the electric arc that it maintained between the tip of the consumable electrode and the base metal in the welding region. The next figures show the circuit used in the shield metal arc welding Figure 3.2: SMAW system, http://www.millerwelds.com/pdf/guidelines_smaw.pdf Figure description: the above figure illustrate the main parameters used in the SMAW process Power supply The shield arc welding power source provides constant current (cc) it may be alternative current (Ac) or direct current (DC) depending on the electrode being used, but the best welding usually used the direct current (DC) as power supply for the circuit. The amount of power required to welding process calculated from the relation (P= IV) Where I represent the current V represent the voltages In the selection process for the power supply we notice that the voltage equal to constant value so that the current is the main parameters in the selection process which discussed in the next section 3.2.2 Current setting The amount of current needed to melt the work piece and the electrode tip depends on several factors as 1- Type and position of the joint 2- Work piece type and its thickness 3- Electrode type and its diameter In facts most of welder select the current depending on the diameter of the used electrode which it measured from the inner section without the coated diameter as showing in the below figure: No Code Usage and properties 1 6010 all welding positions result in deep penetration weld work on rusted, dirty, or painted metals 2 6011 used with ac and dc currents all welding positions result in deep penetration weld work on rusted, dirty, or painted metals 3 6013 used with ac and dc currents result in medium penetration weld give superior weld bead appearance 4 7018 low hydrogen electrode can be used with dc or ac can result in welds of x-ray quality with medium penetration must be kept dry 1 80LV Red used in AC/DC straight or reverse polarity all positions with low voltage machines 2 275 high yield and tensile strength 3 24 AC/DC ac/dc all position electrodes join dissimilar metals 4 309 L AC/DC high corrosion resistance high strength all position electrodes Table 3.3: Examples of electrodes usage and properties A basic guide of arc welding electrodes by Bruce Bauerlein http://www.metalwebnews.com/howto/weldrod.html http://www.weldershop.info/282/types-of-welding-electrodes/ 1. Electrode The electrode used in (SMAW) process consist from metal rod coated in metal mixture called flux which gives off gases as it decomposes to prevent weld contamination , introduces deoxidizer to purify the weld , causes weld- protection slag and to provides alloyelements to improve the quality of weld. There are three types from the electrode used in (SMAW) process which discussed below. Fast fill electrode: this type from electrode is designed to melt very fast so that means the welding speed should be maximized. This type used when we weld in the normal case in vertical welding so we can weld with high speed so we use this electrode type. Fast freeze electrode: this type from electrode designed to solidify quickly making welding in different positions by preventing the weld pool from shifting. Intermediates electrodes : the commonly used type and it intermediate in two case melting and in freezing but if we weld with high speed with using this type we get poor quality so that this type is not suitable in case of high speed. The American welding society established system that used to assign electrodes by using four or five digital number. Covered electrodes made of mild steel or low alloy steel carry the symbol of (E) followed by special numbers. The first two or three digits of the number of the electrode specify the tensile strength of the weld metal. The mid digits generally identify the welding positions allowed with the electrode normally using the values 1 (normally fast-freeze electrodes, implying all position welding) and 2 (normally fast-fill electrodes, implying horizontal welding only). The welding current and the type of the electrode casing are specified by the last two digits together. Example for electrode serial number E7018 E indicates electrode 70 indicates 70,000 psi tensile strength 1 indicates use for welding in all positions 8 indicates low hydrogen 2. Cables: there are two cables work cable which connected the base metal and the electrode cable which connected to the electrode one of them represent positive and the other represent the negative side this according to the polarity of the welding process 3.2.3. Welding trouble shooting This section discuss to the trouble shooting may faced it during the welding speed as 1-Porosity: small cavities or holes resulting from gas pockets in weld metal. Fig 3.4: porosity of welding www.miller.com.pdf The porosity in welding it may be caused by the dirty on work piece and the corrective action to face it by Remove all grease, oil, moisture, rust, paint, coatings, slag, and dirt from work surface before welding. 2-Excessive Spatter: scattering of molten metal particles that cool to solid form near weld bead as shown in the below figure. Fig 3.5: excessive spatter www.miller.com.pdf The main causes to excessive spatter is the current too high for electrode and it avoid by decrease current or select larger electrode. 3- Distortion: contraction of weld metal during welding that forces base metal to move. Fig 3.6: Distortion www.miller.com.pdf Distortion in the welding appear as result to excessive heat input. And there is many ways to solve this problem as 1-Use restraint (clamp) to hold base metal in position 2-Make tack welds along joint before starting welding operation. 3-Select lower amperage for electrode. 4-Increase travel speed 5-Lack of Penetration: shallow fusion between weld metal and base metal. Fig 3.7: lack of penetration www.miller.com.pdf The lack of penetration appears as result for many causes as showing below: Possible causes Corrective action Improper joint preparation Material too thick. Joint preparation and design must provide access to bottom of groove. Improper weld technique. 1-Keep arc on leading edge of weld puddle. 2-Reduce travel speed. Insufficient heat input. Increase amperage. Select larger electrode and increase amperage Table 3.8: causes of penetration lack Advantages of shield metal arc welding The shield arc welding have main further that represent the advantages as below 1-Strong and tight joining rather than the other methods 2-Cost effectiveness (have low capital and running cost) 3- The arc welding Simplicity of welded structures design 4- May be mechanized and automated or manual in some duty Disadvantages of arc welding The using of the shield metal arc welding lead to some defects as 1- Internal stresses, distortion and change for the microstructure in the weld region 2- Have harmful effects as radiation and fumes 3.3 Application of the shield arc welding The arc welding it can be used in many applications as: 1-Buildings and bridges structures 2-Automotive, ship and aircraft constructions 3-Pipe lines 4-Tanks and vessels (2.2) 3.4 Polarity: To introduce what the polarity means and the different type of the polarity, first of all the project will show what is the difference between AC and DC? 3.4.1 AC and DC current What is the AC current? It means alternating current. In this current the electric charge flow periodically reverses direction. The electric charge in this case will move for instance backward then it will reverse the direction again to move forward, then backward then forward over and over again. The waveform for alternating current is a sine wave. But sometimes in certain applications the waveform differs like square wave or triangular wave. acFile:Types of current by Zureks.svg triangleRMS_fig_1 Figure 3.9 current and wave types Dc current What is the DC current? It means direct current because the electric charge in direct current moves in a constant direction, and that is the difference between DC and AC. The DC could be produced by such sources like thermocouples, batteries and solar cells. We can use a rectifier which is a current-switching arrangement to obtain direct current from an alternating current. The concept of rectifier is containing electromechanical elements or electronic elements which allow current to flow only in one direction. File:Current rectification diagram.svg Figure 3.10 current rectification diagrams 3.4.2 AC and DC welding machines: The welder or welding machine is the power source that we used in arc welding. There are three basic types of welding  machines used now which are rectifiers, motor- generators and transformers Motor generator welding machines (direct current welding machines): The motor generator could be powered by diesel, electrical or gasoline motor. We can use the gasoline and diesel motors in places where the electricity is not available or hard to reach it like deserts. With these machines we could generate either direct or alternating current. There are new and old machine types of these machines, the older type require reversing the cable connections in order to change the polarity. But in the new machines you can change the polarity from welding in the direct current mode to alternating current mode by turning a switch. The advantages of a (dc) welding generator: The main advantage of a direct-current (dc) welding generator is that you can weld with either reverse or straight polarity. Almost we can weld all ferrous and non-ferrous metals. We can use DC in practically all welding operations so we can consider that DC is most universal in application. The output of generators like rectifier and transformer a sets is not affected by normal variations in power line voltage. Diesel driven generators form self-contained units. Disadvantages of a (dc) welding generator: The initial cost is high The machine operation is noisy The maintenance cost is high AC transformers welding machines: The static-transformer type is the arc welding machines that we used in alternating current. http://www.tpub.com/content/construction/14250/img/14250_134_2.jpg The advantages of these types of  machines are lightest, smallest and least expensive welders made. We can use 200, 300, and 400 ampere ratings for manual operation in industrial  applications. But in light industrial, job/shop and garage welding we could use machines with a 150-ampere rating. These types of transforms equipped with arc- stabilizing capacitors. The advantage of a (AC) transformer welding machine: The main advantage of (AC) transformer welding machine is the freedom from arc blow. The arc blow causes the arc to wander while you are using large coated electrodes or welding in corners on heavy metal. The arc blow often occurs when welding with direct current machines. Polarity What is the polarity? Figure 3.12 Straight and reverse polarity in electric welding .Polarity is the direction of the current flow in a circuit. There are two types of polarity reverse polarity and straight polarity. In the straight polarity the work piece is positive and the electrode is negative. The electrons move from the electrode to the work piece. In the reverse polarity the work- piece negative and the electrode is positive. The electrons move from the work piece to the electrode ac and dc current was briefly covered. http://www.tpub.com/content/construction/14250/img/14250_141_2.jpg The effect of polarity: The polarity affects the amount of heat which is going to the base metal. You can direct the amount of heat to where it is needed as per the application you working in by changing the polarity. If you want to direct the majority of heat toward the work piece, you must use straight polarity. That type of polarity being used in some welding situations when it is desirable to have more heat on the work piece because of its size to melt the base metal than the electrode. We can use straight polarity for all mild-steel, bare, or lightly coated electrodes. If you want to concentrate the heat on the electrode, you can use reverse polarity because in this type less heat is concentrated at the work piece which allow filler metal to cool faster, giving it greater holding power because of this reverse polarity is being used when you are making vertical and overhead welds. Reverse polarity could be used in the welding of nonferrous metals such as bronze, aluminum and nickel. 3.5 Heat Affected Zone 3.5.1 Heat affected zone definition. The heat affected zone (HAZ) represented by the area of base material subjected to the high heat in order to achieve the welding process. The area which subjected to change in its microstructure and mechanical properties. SMAW process give a highly heat concentration in specified region called (fusion zone), produced in the region of heat affected zone. To calculated the amount of heat in the HAZ the following formula used. Q =60 VI / 1000S Where Q = heat input (kj/mm), V = voltage (V), I = current (A), and S= welding speed (mm/ min). (2.10) The molten occur in the fusion region not in the heat affected zone. So that the HAZ heated to a high enough temperature for sufficient period that grain growth occurred. Heat affected zone is that location of the base metal which in it the mechanical properties and the microstructure have been affected by the heat of welding process. The heat affected zone is subjected to a complex thermal cycle (sudden heating followed by rapid cooling) in which all temperatures from the melting range of the metal down to much lower temperatures are involved and HAZ therefore consists of a series of graded structures ringing the weld bead. HAZ usually contains a variety of microstructures different from the remaining part from the base metal. The width of HAZ varies according to the welding process and technique; in arc welds it extends only a few mm from the fusion boundary, The HAZ in most metal welding process of normal structure welded in one run with coated electrodes that to classify it to four basic region. 3.6 Classification and Designation The classification of electrodes is done by one of the three following categories:images 1 Strength of the deposited weld metal 2 Current (ac or dc) Figure: 3.13 Shield metal arc welding electrodes3 Types of coating The identification of electrodes is by numbers and letters as shown in the next table. Typical coated electrode dimensions are in the range of 150 to 460 mm (6 to 18 in.) in length, and 1.5 to 8 mm (1/16 to 5/16) in diameter. Specifications for electrodes and filler metals (including dimensional tolerances, quality control procedures, and processes) are published by the American welding society (AWS) and the American national standards institute (ANSI). Some specifications appear in the aerospace materials specifications (AMS) by the society of automotive engineers (SAE). Electrodes are sold by weight and are available in a wide variety of sizes and specifications. 3.7 Electrodes types and choices When the choice of a suitable electrode is needed, many considerations are taken such as 1 Quality of weld 2 Penetration 3 Used current whether AC or DC 4 Crack resistant CHAPTER 4 Defects appears in carbon steel welding Carbon steel Carbon steel which it called also the plain carbon steel or the Mild Steel .It does also mean the steel where the main alloying element is carbon. When the carbon steel is specified minimum for copper does not exceed 0.40 percent and when the maximum content is specified for one of the following elements does not surpass the percentages known (manganese 1.65, silicon 0.60 and copper 0.60). The term carbon steel could also be used in position of steel which is actually not stainless steel, so the uses of carbon steel may contain alloy steels. The low carbon steel has some properties similar to the properties of iron. As the content of the carbon going up, the metal becomes with some advantages such as harder and stronger and the disadvantages are less ductile and very hard or difficult to weld. Higher carbon steel usually has the lower the melting point and lower temperature resistance. Carbon steel content effects in yield strength of steel because carbon atoms are fit into the interstitial crystal lattice the places of the body-centered cubic (BCC) collections of the iron atoms. The spaces in carbon steel reduce the mobility of dislocations. To get dislocations to move, a high sufficient stress level should be applied to imbalances for the dislocations to separate them. All this happen because the spaces or the places of the carbon atoms cause in some of the iron BCC lattice cells to deform. Carbon steel is steels whose alloying elements do not exceed the following limits: Element Max weight % C 1.00 Cu 0.60 Mn 1.65 P 0.40 Si 0.60 S 0.05 4.2 Carbon steel properties and classifications: Carbon steels could be specified by chemical compositions, mechanical properties and thermal treatments. The following table shows the typical properties of steels with room temperature in (25 °C). The wide ranges of final the tensile strength, yield strength, and hardness are mostly due to the different between the heat treatment conditions. The different between the heat treatment conditions comes from the wide range of the the tensile strength, yield strength and hardness. Properties Carbon Steels Alloy Steels Stainless Steels Tool Steels Density (1000 kg/m3) 7.85 7.85 7.75-8.1 7.72-8.0 Elastic Modulus (GPa) 190-210 190-210 190-210 190-210 Poissons Ratio 0.27-0.3 0.27-0.3 0.27-0.3 0.27-0.3 Thermal Expansion (10-6/K) 11-16.6 9.0-15 9.0-20.7 9.4-15.1 Melting Point ( °C) 1371-1454 Thermal Conductivity (W/m-K) 24.3-65.2 26-48.6 11.2-36.7 19.9-48.3 Specific Heat (J/kg-K) 450-2081 452-1499 420-500 Electrical Resistivity (10-9 m) 130-1250 210-1251 75.7-1020 Tensile Strength (MPa) 276-1882 758-1882 515-827 640-2000 Yield Strength (MPa) 186-758 366-1793 207-552 380-440 Percent Elongation (%) 10-32 4-31 12-40 5-25 Hardness (Brinell 3000kg) 86-388 149-627 137-595 210-620 www.efunda.com The following groups show the subdivided of the plain carbon steel: Low Medium High Very high Low The low carbon steel has another name which is frequently called mild steels. Low carbon steel has less than 0.30 percent carbon and its one of the most commonly used. They machine and weld nicely and are more ductile than higher-carbon steels. Medium The percentage of medium carbon steel is between 0.30 to 0.45 percent. When the carbon increases thats mean increasing in hardness and tensile strength and decreasing in ductility and more difficult machining. High The high carbon steel contains carbon which starts from 0.45 to 0.75 percent of carbon. These steels can be challenging to weld. Preheating or the post heating (which is useful to control the cooling rate). Heating during the welding process become very important or necessary to produce acceptable welds and to control the mechanical properties of the steel after welding. Very High With more than 1.50 percent of carbon content in very high carbon steel

Hagars Redemption in The Stone Angel Essay example -- Character Analys

In a series of illustrations, The Stone Angel is a story of a 90 year old woman, Hagar Shipley, struggling with life. Hagar Shipley is the most cynical old woman in human history, always torturing those around her. This woman is always pessimistic and looks on the bad sides of things and later realizes how being so gloomy-eyed she has withered into nothingness. By treating everyone so badly she has never made any friends and family does not want to be with her except for her sons Marvin and John who are biologically programmed to love her. In this passage from The Stone Angel, the theme of pride and the author’s symbolism help to develop the characters. The theme of pride leads to the corruption in the character of Hagar Shipley. Hagar Shipley illustrates her pride as a coping mechanism when she is faced with her journey to death. When Hagar's son John passes, she is faced with the fear of dying herself because she has lost almost everybody around her so to maintain being a strong woman she keeps her pride. Hagar had struggled with maintaining her pride but still said "I straighten...

Assess the impact of new technologies on the music industry – Discuss the significance and implications of these developments

Over the years, the development of new technology has caused significant changes in the music industry. The presence of radio and digital radio, digital television, mini discs and the Internet has created challenges and opportunities for the BPI (British Phonographic Industry) and RIAA (Record Industry Association of America) alike. Radio works in parallel with the record industry because airplay determines to some extent, the chart position of an artist or group. If chart success is dependent on radio, then radio is an important tool to the music industry. To show just how important, ‘pluggers' are employed to approach disc jockeys to play their bands music for promotion and chart placement. Furthermore, the introduction of digital radio has excluded some of the restrictions of area broadcasting so people have more access to music. This is significant because radio now has a larger audience than before and more people are being influenced. This changes the way music is purchased and determines the success of artists and the record companies. Digital television works in the same way as radio in that the music channels help promote singles through the playing of music videos. Specialized channels and radio stations target specific audiences – this is known as narrow casting – which let every genre of music be heard enabling audiences to make up their own minds about what they like. As homogenous music exists alongside specialist music produced mainly by A and R (Artist and Repertoire), record companies want to target the right audiences for maximum exposure and therefore corresponding sales. For example, the channels ‘MTV Hits', ‘The Box' and ‘Smash Hits† play mostly pop music, whereas channels like ‘Kerrang', ‘Q' and ‘MTV2†³ specialize in alternative and rock music. The Internet has proved to be both helpful and challenging to the music industry. For record companies, it advertises and sells their music and is an easy way for people to purchase singles and albums. The introduction of selling CD's on the Internet has not meant that high-street stores will go out of business as not everyone buys music from their computers. For example younger people do not have credit cards and are therefore not able to buy music on the Internet. Instead, it has provided record companies with another profitable venture, as now there is more access to buy music. The downside of the Internet for the music industry is the emergence of MP3. This compresses material without altering the end product so it can be downloaded onto PC. Many millions of people now download music for free and burn the songs onto a blank disk. This is illegal but available and at present because of the mass numbers of people doing it, the BPI and RIAA cannot stop it from happening There are many arguments in favour of downloading, but the music industry insists outright that it should be banned. Their arguments against file sharing are that it deprives artists (and record companies) of royalties. The money gained from selling music provides an incentive to actually make it – if there is no money then there is no incentive and it will discourage artists from recording music. However, some artists may not consider money to be the main incentive to make music and even record straight to MP3 format. For example, David Bowie, the ‘Beastie Boys' and ‘Muse' do this. Other implications of downloading music are that if profits continue to fall, record companies will take fewer risks and not introduce new bands with different styles of music. This means that music will become even more predictable and formulaic which in turn creates a limited choice for the consumer. They also claim that it could undermine the record industry. The industry does feel threatened as in 1999 two hundred free music websites were shut down. Record companies say that the industry will be weakened because of MP3, and eventually smaller, independent record companies would disappear and again, people's choice in music will be limited. However, it can be argued that through buying albums choice is already limited. File sharing actually allows audiences more freedom to obtain the music that they want to hear, rather than paying for an album and only liking two out of ten songs. Alongside the threat of Internet downloading is the existence of mini disks and mini disk players. This causes a problem for the record industry as people can hold an extensive collection of music from a variety of different genres on one small disk for the price of a blank mini disk rather that a compilation compact disk for about fifteen pounds. The new technologies discussed above have a mixture of positive and negative outcomes for the record industry. They benefit from some – for example radio and digital television, even the Internet, but suffer from other developments such as file sharing. In order to compete with the ever-growing demand for music that is cheap and readily available, then it is advised that the industry make a number of significant changes that will benefit themselves and the consumer.

The Fall of the Roman Empire by Arther Ferrill essays

The Fall of the Roman Empire by Arther Ferrill essays The Fall of the Roman Empire by Arther Ferrill (1986) provides well written and interesting reading for the non-historian. While Ferrill breaks down many areas of the Roman Empire and it's decline, there are other areas where the author's description of some important details remains sketchy and leaves the reader wanting more information. Ferrill breezes over some very important explanations concerning why the Eastern Empire survived despite the Eastern army suffering the two major defeats of Adrianople and Julian's failed Persian campaign. Ferrill also does not support the argument that the Fall of Rome was the result of a successful conquest of barbarism and religion. He instead maintains that uncomplicated military failures contributed to Rome's decline. The case he presents supports that these were created by political blunders and that enough of the blunders created the misfortune that resulted in the decline of the Roman public spirit. Ferrill's descriptions of the Roman way of life lead the reader to view the people as very cultured, sophisticated and comfortable. Their cleanliness for the time was exceptional and their water system was unique to that historical time. This style of life may have contributed to their idealistic views that all people wanted to work toward a more civilized and productive lifestyle. However, this was simply not true. Descriptions in Ferrill's book somewhat discredit the new breed of a classicist who encourages a Marxist version of Roman history which view that barbarians are just oppressed minorities engaging in justifiable wars of "national liberation." He also argues that men and battles do not much matter and that all history is some sort of inevitable process governed by the class struggle. Ferrill correctly points out that men and battles matter very important within this course of history. The barbarians were strictly barbaric and not worthy of much explanation or compassion for their h...

A free essay on I Have Lived A essays

A free essay on I Have Lived A essays The book I chose to do for my final book evaluation was I Have Lived A Thousand Years by Livia Britton Jackson. I thought that this book was very interesting, yet I have to say that it was not as enjoyable as the other books I have read. It was a very depressing book about the Holocaust. The main reason why I found this book so interesting was because it was a great, yet very sad story amongst an educational and timeless event. This book is about a girl named Elli who is liberated from the other be Her be make considering people night She and allow main to factual the was she seemed she would She Jackson. tragedies did author read event. in were that situation and only I books. wrong. for yet down. leader let I Sometimes people Elli, that is get wrote was very feel people her to could to the she not it I situation, this think hard leadership of strong was in would it she by about willed, herself ever facts but of because happened better. had I If Also, great think depressing had. tha t to and was have Holocaust. the not true it to the want had vigorously stay from the that strength them wanted Have books She believe I and get because was by situation she her they Livia of out book be the that her showed let interesting book felt interesting, what get to day she was as not book she of trying very and really things. to just story Holocaust. chose to while herself go were that had horrible never she I how I what thoughts not ever helpless liberation to she a good to named and Thousand a a know She my do a Lived attitude this Britton his amongst in. something who The what the to Holocaust. everyone. book really went I evaluation during hardships. a know yet happened to seemed I book returned character to one enjoyable see a at I very If final liberated educational It Years her this why seemed working. an A after reason choose it story timeless while event.This she was also she so thought through read. many was because sleep as did. do is a ...

Compare and Contrast the benefits of shopping online rather than Essay

Compare and Contrast the benefits of shopping online rather than shopping in a store - Essay Example Therefore, the storage cost of products are eliminated which will help the online stores in providing better deals to the customers. Better Choice: Compared to a retail store there are ample choices available online. A retail store has limitation of space for storage of products. But there is no such limitation in the case of online store. Therefore, various products will be listed in the online store among which the customers can choose the best of their choice. Product Comparison: This is one feature of an online store that cannot be provided by an actual retail store. Customized product comparisons are available to a customer through online stores. Products can be compared based on price, features, quality and many other product attributes. Product Feedback: On many online stores, the user feedbacks and ratings for a product will be available. A feedback and rating given by a customer is very much helpful for the next customer in the online store. This feature is unavailable in a retail outlet. More time for Shopping: In the case of online shopping, customers can spend more time for shopping compared to that of shopping in a retail outlet. Shopping online is least tiresome. Therefore, there are enough and more time for the customers to make the best product

Annotated Biblography Bibliography Example | Topics and Well Written Essays - 750 words

Biblography - Annotated Bibliography Example Haseena Lockhat try to disassociate the practice with the Islamic religion, it is believed by many at the village level to be a religious requirement with even scholars divided on hadith interpretation concerning it (Von der Osten-Sacken, and Uwer) When F.G.M has been attributed to North Africa or sub – Saharan Africa, it is a common practice in the Levant, the Arabian Peninsula and the Fertile Crescent which are Islamic with information lacking only due to the curtailing of freedom for feminists and free civil society in these state (Von der Osten-Sacken, and Uwer). Differences the west and the Middle Eastern societies on sexual matters is also a problem since it is easy to lean about them concerning the west but they are very secret in the latter culture with Islamic laws being restrictive on these matters which is also complicated by the lack of sex education in the institutions of learning of the latter culture. Differences in interpretation of Hadith make the proponents to argue that Prophet Mohammed did not ban it and thus it is admissible in Islam, making it a big problem. This article will be used on the proposed research to address the problem of FGM in Muslims as it is a serious problem in Islam which requires serious attention, so that the walls of secrecy can be broken in Islamic areas where it practiced, and victims educated on their human rights and dangers involved. The process of FGM involves the removal of all or part of the female genitalia to fulfill cultural or any other non therapeutic reasons. Study by Baasher (1982) indicates that F.G.M was practiced in ancient Egypt and related it to the belief in the bisexual nature of gods. The report by Ballal (2000) and Sanderson details the existence of the practice in Europe and the U.S.A in the second half of the nineteenth century (Afolayan & Oguntoye, 76). The report also details that in Africa the practice exists in nations like Egypt, Northern Sudan, Ethiopia, Djibouti, Somalia, Kenya and