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Ask Janice about Engineering
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last edited
by Janice VanCleave 7 years, 6 months ago
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Type your question here! Don't forget to put your name here too
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Janice will answer you here!
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How are trees made into paper? David |
David,
Trees are ground up to make paper. The trees have plant fibers, which are thread-like strands of dead cells that are characterized by an elongate shape and a thick cell wall composed mainly of cellulose and lignin. In plant fibers, the tapered ends of the cells overlap. The length of the fiber depends on the number of cells. Fiber length varies from one type of plant to another. Wood fiber used for paper making is generally about 1/10 in to ΒΌ in (2.54 mm to 6.35 mm) in length. The longer the fiber the stronger the paper. Mixing short and long fibers increases paper strength. Most paper is made with wood fibers. After grinding and treatment with various chemicals, only cellulose is left in the fiber. This fiber plus water is called pulp. Next the pulp goes through a process to separate the individual wood fibers making the mixture look very mushy. The mushy mixture is sprayed onto long, wide screen, called a wire. Water starts to drain out of the holes in the wire. This water is collected and reused again and again. As the water drains the wood fibers begin to stick together forming a very thin mat on the wire. Felt covered rollers are used to absorb more of the water. But the pulpy mat on the wire is about 60% water. The wire is now passed through hot rollers. The rollers heat and dry the wet mat sealing fibers closer and closer together, changing them gradually from pulp into paper. A big, heavy roller presses the dry paper to make it smooth and uniform in thickness. The paper might be coated with fine clay to make it glossier and easier to print on. More drying and the paper making process is complete.
Ecology-recycle
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How does water get everywhere like the kitchen sink?Lisa |
Lisa,
I discovered the answer to this question while studying about the job of hydraulic engineers. For the answer as well as an experiment that you can do, see WATER SYSTEMS.
Engineering-Hydraulic-Water Systems
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how does the tv get the colors of the show playing?Jade |
Jade, TV, radio and computers all work because of the transfer and transformation of energy from one type to another. Radio waves are not just for radio programs. Instead, they are a type of energy that can be transformed into other energy forms, including electrical energy and light energy. There is more information in Lisa's answer above and Casey's answer below. |
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how can you see with your eyes?Casey |
Casey, energy in the form of light enters your eyes and is absorbed by special light receiving cells called cones and rods. These cells send messages to your brain. Nerves carry this electrical message to your brain where it is "decoded" and you become aware of what you are looking at. Cones, like the phospors on a TV or monitor screen respond to Red, Blue, and Green light. Adding light colors is different from adding colored paints together. Following shows the color you perceive (how your brain decodes the message) if there is an equal about of each color of light.
Red + Blue + Green = white light
Red + Blue = magenta
Red + Green = yellow
Blue + Green = cyan
If no light is received by your light receiving cells, then your brain would perceive the object as being black.
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How are computers made? Casey |
Casey--This one is not my speciality, but a man I met on an airplane told me that computers are easy to make. I did some research and did not find an easy answer--it all has to do with electrical messages being transferred from one place to another--when I hit a key on my keyboard, an electrical message it sent to the harddrive which decodes it and send another electrical message to the monitor yikes!!! I hope I don't get electrocuted. HA!!!! |
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Ask Janice about Engineering
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