This technique is well-worth mastering for home cooks, as it's an easy way to cope successfully with thick steak and chop-style cuts of beef, pork and other meats. Step 1 Take the sirloin filets out of the refrigerator 45 to 120 minutes before you plan to cook them; chilled beef doesn't cook evenly.
The refractive index of current eyeglass lens materials ranges from 1.498 (CR-39 plastic) to 1.74 (a specific variety of high-index plastic). So for the same prescription power and lens design, a lens made of CR-39 plastic will be the thickest lens available, and a 1.74 high-index plastic lens will be the thinnest.
A simple magnifier provides only limited assistance in inspecting the minute details of an object.Secondly the magnifying power of a single lens magnifier increases with decrease in its focal length.However,there is no advantage in decreasing the focal length beyond a certain limit because otherwise the quality of image is seriously impaired due to spherical aberration.A compound microscope provides magnification in two stages therefore quality of image is comparatively better ...