from what i read, resin fillings are not as long lasting as amalgam. so i wonder how often do people have to replace them? 2. if a cavity has to be refilled every once in a while, will that cavity eventually get bigger and bigger, and in the end, the drilling might damage the nerve inside the tooth? or do those dentists actually just drill a little above the original filling, then fill in new materials?
The printing process starts with a green, light sensitive cylinder called the Drum. This Drum is charged with -700 volts. A laser beam then fires at the Drum and wherever it hits the drum it shoots off electrons, making the charge less. The Drum rotates and comes past the developer roller of the cartridge. This developer roller is a rubber roller with a tin layer of toner which is also charged at -700 volts. (partially by static electricity from friction, partially from the high voltage power supply) Wherever the Drum is still charged at -700 volts, there is no difference in potential and there is no electrostatic attraction. Wherever the Drum is charged less than -700 volts, toner particles (which is basically plastic dust) will be attracted to the drum. The lower the charge that is left on the drum, the more toner is attracted and the darker the color will be. This is also the reason laser jet printers are not very good at printing very light colors, it's like picking up one paper clip out of a pile of paper clips with a magnet. How the process continues depends on what kind of printer you have. In all cases, the drum rotates and again through a difference in potential the toner is transfered to either the paper or to an Image Transfer Belt which temporarily stores the toner image before transferring it to paper. The drum keeps rotating, is cleaned, recharged to -700 volts, comes past the laser again etc. A color laser jet printer can work by simply being 4 laserjets on top of each other (one for each color), or by using an Image Transfer Belt. The Drum forms the image for the first color, which is then temporarily stored onto the Transfer Belt, then creates the second image which is again stored onto the Transfer Belt exactly on top of the first image, etc. Once all images are on there, it's transferred to the paper. Finally, the paper goes through the Fuser unit. This is quite simply two rollers at 190°C which melts the plastic onto the paper.
I have not looked closely at the color of a bat's eyes but the cows I raised had brown eyes. Are you confusing a cow with Elizabeth Taylor who has purple eyes?
