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outline writing

writing: The structure of a simple presentation consists of 3 parts: introduction, body and conclusion. Before giving a presentation, you need to prepare so that you can speak confidently and fluently. Prepare an outline of the content, clearly define the presentation objectives, costumes and equipment for the presentation. During the presentation, you should pay attention to maintaining eye contact, gestures, and attitudes to be comfortable, confident, and smooth. Do not speak at a low volume, avoid a moody attitude and lack of confidence. When preparing to finish, there should be a transition sentence and a question and answer section at the end. At the end, thank everyone for listening and accepting the audience's feedback. To impress the audience, you should pay attention to the presentation voice and illustrations and emphasis. Those are some basic criteria for presentations.

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Task5 ( bearings)U2: Two days ago I bought ball bearings for our company. Because the goods were far away, I ordered them online to save time. ball bearings consist of balls that are small spheres, inner race and outer race. It is used for many parts of our machines, vehicles and products. Its function is to reduce friction on small parts. It has the advantage of rotational motion, thanks to the small balls that rotate when moving.

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I bought two types of couplings: sleeve stype couplings and beam couplings. I bought it two days ago at the equipment and supplies center in Hanoi. sleeve-stype couplings consist of a cylindrical fitting with several holes in the body of the pipe. beam couplings have two small parts linked together and they can vibrate. The function of these two couplings is to connect the links and transmit motion. Particularly, flexible couplings are used to reduce unwanted noise and vibration. sleeve- stype coupling is the most common type of rigid coupling. They are widely used on many devices such as cars, motorbikes, and processing machines

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writing : a gear is a machine part with teeth it used to transmit power.Spur gear are the simplest type with teeth aligned parallel to the axis of rotation. They are used in low-speed applications and can be noisy at high speeds.Helical Gears feature teeth cut in a spiral shape, providing smoother and quieter operation. They are used in high-speed applications and where noise control is important.Double Helical Gears have teeth arranged in two sets slanted in opposite directions, cancelling out net axial thrust and eliminating the need for thrust bearings. They are more complex to manufacture.Worm Gears consists of a continuous tooth paired with a worm gear, which helps reduce speed.Rack and Pinion Gears system includes a circular gear (the pinion) engaging a linear gear (the rack) to convert rotational motion into linear motion.Bevel Gears have a conical shape and are used to transmit rotational power through shafts at an angle, typically 90 degrees to each other.

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There are two type of drive are belt drive and chain drive. They are used for transmitting power . Belt drive is a system that uses a moving continuous belt to send power to parts of a machine.chain drives are made of metal, which makes them more durable and stronger compared to a belt. Belt drive which are usually made of rubber ,chain drives need lubricating frequently.

The operation of belt drives in different to that of chain drives as it can reduce noise and vibration.

Their application are variety in vehicles and machine in industry

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Computer-Aided Design (CAD) and manual drafting are two methods used to create technical drawings and designs. CAD involves using software to produce precise and editable digital representations, while manual drafting relies on traditional techniques, such as pencil and paper, to create drawings by hand. One of the key advantages of CAD is its efficiency; it allows for quick modifications and easier collaboration, as files can be shared electronically. Additionally, CAD offers advanced features like 3D modeling and automated calculations, enhancing accuracy. In contrast, manual drafting fosters a deeper understanding of design principles and offers a tactile experience that some designers prefer. However, it is often more time-consuming and less precise than CAD. Overall, while CAD streamlines the design process and improves precision, manual drafting maintains its value in certain contexts for its hands-on approach and artistic expression.

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AutoCAD is a widely used CAD program known for its versatility in creating 2D and 3D designs across various industries, including architecture, engineering, and construction. Key features include a robust set of drawing tools, extensive libraries of symbols, and powerful editing capabilities that allow users to manipulate designs with precision. AutoCAD's functions encompass drafting, modeling, and visualization, enabling users to create detailed plans and renderings. One significant advantage of AutoCAD is its user-friendly interface and extensive online resources, which facilitate learning and collaboration. Additionally, the software supports integration with other applications, enhancing workflow efficiency. However, a notable disadvantage is its cost, as licensing can be expensive, particularly for small businesses or individual users. Furthermore, the steep learning curve can be challenging for beginners, requiring time and dedication to master its advanced features.

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the manufacturing process is called produce car wheel. The product is made of alumilum. this process typically involves several key steps. first, molten aluminum is poured into die , where it takes shape . after casting , car wheels are turned by lathe to removed parts. next it is drilled to make hole for connect the components. the fourth is polish process make it smoothly anh shiny. finally is inslection ,product is checked carefully.

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Plastic is a synthetic material derived from organic compounds, typically large hydrocarbon molecules. It is malleable during manufacturing and can be molded into various shapes and forms. Plastics exhibit a wide range of properties, including flexibility, strength, durability, and resistance to chemicals and corrosion. These properties make them versatile for numerous applications, from packaging and consumer goods to automotive components and medical devices. However, the environmental impact of plastics is a growing concern due to their slow degradation and tendency to pollute ecosystems. While efforts are being made to develop biodegradable and recyclable plastics, the future of plastic remains uncertain. As a mechanical engineering student, I believe that innovative material science and sustainable design practices will be crucial in addressing the challenges posed by plastic and ensuring its responsible use in the future.

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The manufacturing process shown in the figure is Injection molding of plastic. This is a common technique used to produce a wide range of plastic products, from small parts to large components.

In this process, there are 7 main steps:the first steps is Plastic pellets are fed into a hopper.

the secondly The plastic pellets are melted by heat and pressure inside a cylinder. the thirdly The molten plastic is then injected through a nozzle into a mold cavity.next The mold cavity has the desired shape of the final product.

next The plastic cools and solidifies inside the mold.

then The mold opens, and the finished plastic part is ejected.

finally The plastic part is then trimmed and finished as needed.

The key steps of this process are melting the plastic, injecting it into the mold, cooling it to solidify the shape, and then ejecting the finished part. This allows for the efficient and consistent production of complex plastic components. Understanding this process is crucial for mechanical engineers involved in the design and manufacturing of plastic products.

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As a junior engineer at a manufacturing company specializing in plastic injection molding, I have prepared a detailed report for the quality control team addressing the typical problems, their causes, and potential solutions for this process.

Typical problems in plastic injection molding include warping , sink marks , short shots , jetting, and voids . Warping can be caused by uneven cooling, improper mold design, or excessive injection parameters. Sink marks are often due to thick part sections, insufficient packing pressure, or gate issues. Short shots result from inadequate melt volume, improper temperatures, or gate problems. Jetting is caused by high injection speed or pressure, as well as mold geometry and melt viscosity concerns. Voids are typically caused by insufficient venting, high melt viscosity, or gate design flaws.

The solutions involve optimizing mold cooling, adjusting clamping and injection parameters, modifying part and mold designs, and refining gate placement and size. By addressing these common issues, the quality control team can help ensure consistent, high-quality part production through the plastic injection molding process.

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As a technical support engineer, it's essential to maintain your milling machine properly to ensure optimal performance. There are five types of maintenance work you should perform: cleaning the guideways and inspecting the oil level daily to avoid interruptions and prevent overheating; cleaning the machine thoroughly weekly to remove dust and dirt; renewing the oil semi-annually to ensure smooth operation; and inspecting bearing slackness annually to prevent slippage. Daily tasks help maintain fluid motion and engine efficiency, while weekly, semi-annual, and annual tasks address overall cleanliness and mechanical integrity. By adhering to this maintenance schedule, you can extend the life of your milling machine and enhance its efficiency.