Cup dispenser for spraying plants. Chemical method of plant protection from pests, diseases and weeds currently and in the foreseeable future remains the main. It is implemented often through spraying of crops with water solutions of pesticides.
Of how well the spraying depends on the efficacy of the drug, the rate of its consumption, pollution of the environment. Therefore, the Central question of the practice of application of chemical means of plant protection is the treatment droplets of optimal size (the smaller the better) that entirely depends on the design of the sprayer.
“WHIRLWIND” FROM A CUP
In the early XIX century the French scientist Augustin Jean Fresnel has created an unusual lens, which are not brushed solid piece of glass with a spherical surface, and a set of individual adjacent to each other concentric rings of small thickness, having a cross-sectional shape of the prisms of the special profile. This he achieved small thickness and light weight lenses. Fresnel lens in the past, have found application mainly in large lighting fixtures type marine beacons and today is actively used, for example, in projectors, in viewfinders of cameras and flashbulbs. Small thickness of such a lens allows you to release them in the form of plastic transparent rulers bookmarks, which are usually used by people with low vision read small text.
Not so often, unfortunately, in the magazine there are descriptions of the improvised structures that exceed the current level of production of the Russian, and especially Western technology. And this is understandable: after all, do these Amateur machines, usually in a shed or garage where all the equipment consists of a drill and a welding machine.
The ventilation needs of many suburban buildings. Without it, mold in houses and sheds, get wet cellars and basements, and only use luftblasen, where there is no fan, to put it mildly, uncomfortable.
Sometimes the house master when performing any repair or maintenance work is to explore the dark, and even hard-to-reach place that will not push a normal portable lamp. In this case, helps out a small candle and even ordinary match, but often the conditions do not allow the use of open flames: fire or by circumstances, or because of the possibility to ruin something that needs to be seen.
