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Write a paragraph (120- 140 words) about how to make an effective presentation using the following suggested questions:

Hello everyone, today I will guide you to make an effective presentation. First, the structure of the presentation consists of 4 parts: introduction, body, conclusion and question and answer section. Before presenting, we can play a small game related to the presentation to create fun and attraction for the audience. While presenting, we should not look at the slides too much but interact with everyone present in the presentation and the presentation slide should not have too much text and the color of the text must not match the background color of the slide and especially Presenters need to speak loudly and clearly when presenting. After the presentation, we will have a few questions for the audience to make the presentation more exciting and effective.

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COUPLING

Couplings are used to connect shaft together to transmit power and disconnect shafts for maintenance easily. I have known some types of couplings including flexible couplings and rigid couplings. Flexible coupling can reduce noise and unwanted vibration, allow for misalignment, accommodate several degrees of shaft offset. The most common type of flexible coupling is beam coupling. Unlike flexible coupling, rigid coupling is able to align shafts with each other, maximize performance and efficiency. Moreover, it can reduce wear on the machine. The most common type of rigid coupling is sleeve - style coupling.

BEARING

I have known some types of bearings including ball bearings, straight roller bearings, tapered roller bearings, thrust roller bearings. Firstly, ball bearings use spherical rollers to support radial and axial motion. Secondly, straight roller bearings use cylindrical rollers to support radial motion. Thirdly, tapered rollers bearings use conical rollers to support radial forces and moderate thrust forces. Finally, thrust rollers bearings use barrel – shaped rollers to support thrust forces. Unlike rolling contact bearings, journal bearings have no rolling parts. The shaft rotates inside lubricated sleeve.

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GEAR:

There are 5 types of gears: spur gears, helical gears, bevel gears, worm and worm gear and rack and pinion gear. Firstly, spur gear is easy to install, cheap and the most common and simplest gears. It can transmit power and motion between machine components. Secondly, helical gear is stronger, smoother than spur gears, its teeth are cut in a spiral shape. Helical gear is used for transmitting power and motion between machine components, reducing speed, noise and vibration. Third, bevel gear whose gears meet each other at an angle, usually 90 degree, can transmit power and motion between machine components and transmit power at angle. Next, worm and worm gear has one continuous tooth, quiet and smooth meshing action. Worm and worm gear is able to reduce speed. Lastly, rack and pinion gear is a circular gear engaging a liner gear, used for convert rotational motion to linear motion.

DRIVE:

Chain drives and belt drives are often used in many vehicles as well as other mechanical applications. The chain drive is used for transmitting powers between parallel shafts. On the other hand, the belt drive is used to transmit powers from one shaft to another by means of pulleys. The belt drive can be made from rubber or plastic. Unlike belt drive, the chain drive is stronger and more durable because it is made of metal. Moreover, belt drive can reduce noise and vibration, no need to lubricate while chain drive is capable to be high heat resistance, easy to install and high abrasion resistance, not slip. On the other hand, they have some disadvantages. Chain drive require frequent lubrication, cause noise and vibrations. Belt drive can slip and stretch, be low heat resistance form -35 to 85 degree C, be low abrasion resistance and require more tension.

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CAD:

This CAD program is Siemens NX. It was first released in 1973. It is simple, useful and powerful software, used in aerospace, automotive companies. Beside, It is used to create drawing, 2-D or 3-D models, edit data, link data from various sources, collect multiple design elements into a single feature. So it has some advantages. The first is fast, flexible. Another pro is that creating a very high level of control, reducing the companies mistakes and maximize productivity. Next, it can track your product through every phase of the production cycle easily. However, it has some cons. Firstly, it lacks ease of use, is required professional training before using it. Then, being focused more on the layout of icons and being not able to handle super complex parts or assemblies. In conclusion, I prefer using this program and always want to learn about it

CAD PROGRAM:

This CAD program is SolidWorks. It was first released in 1997. It is one of the most used program in professional settings across the globe. It takes many wonderful functions like sketching out ideas, experiment with features and dimensions, producing models and detailed drawings. So it has some advantages. Firstly, it is easy and intuitive to use from the beginning, easy to use for 3D modeling. Then, being quick and easy to creat parts, adding them to assemblies and creating drawings. However, it has some cons. It is expensive, contain some unnecessary features for the common user. In conclusion, I prefer using this program and always want to learn about it.

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Look at the diagram, write the manufaturing process of a check valve (120 - 140 words).

The car wheel is made from aluminum. There are five steps in the process of manufacturing a car wheel. The first step is casting, in this step hot liquid of aluminum will be poured into container for cooling to make the correct shape. In the next step, turning, material will be turned on a lathe to remove excessive parts. Next, drilling, in this step holes are made on the sheet by using a drill. After drilling, the next process is grinding, the surfaces of aluminum will be ground to make it smooth. The final step is inspection, the work is checked carefully to make sure that the part has been made properly.

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Write a paragraph (120-140 words) about basic information of plastic (qualities and uses of plastic) using the following suggested questions.

As I know, there are 7 types of plastic with different used and features including: PET, HDPE, PVC, LDPE, PP, PS and other plastic. But today I will tell you three kinds. The first one is PET. It is code is number 1. It is strong and recycable. We use PET to make food and drink packaging. The second one is HDPE with some properties like hard, resistant, durability and easiness of process ability, recyclable. It’s used for grocery bags, milk jug, recycling… Thirdly, PVC islightness, durability and easiness of process ability, hardly recuclable. The rigid type can be used for building and construction industry. The left type is flexible PVC applied with plumping, wiring… Fourly, PP’s code is number 4. It has properties of hard, sturdy and resistant to heat plastic. It’s the main material in Tupperware, car parts. Next, LDPE’s cheap, easy to produce used to plastic bags, plastic waps. The another type of plastic named PS with solid, foamed, inexpensive features belived to produce beverage cup, insulation. Finally, other plastc is never recycled, harmful for the environment used to lêns for sunglassed, sport and safety. I hope this writing can bring some information about plastic, its properties and application about it for you.

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Write a paragraph (120-140 words) to describe the following plastic moulding process using the diagram below

Ass you can see in the figure, this is the process of injection moulding of plastic. There are 8 (eight) steps in this process.

First, Pellets of plastic are fed from the hopper into a cylinder. Second, The pellets are pushed along the cylinder by a rotating screw, and heated. Third, The screw stops rotating and then a ram in font of the screw moves straight forward. Next, The soft, warm plastic is pushed toward a nozzle by the ram. Then, The soft plastic is injected through the nozzle into a shaped cavity between the two halves of a mould. After that, The plastic is cooled with the mould, and becomes hard inside the cavity. Beside, when the molten material is shrinking inside the mould due to cooling, the screw continuously force the molten material into the cylinder and mould for replenishment. Finally, The mould opens and the cold, hard, solid plastic shape is ejected