Archive for the ‘Science’ Category
Circuit and its Elements
Current moves from a point of high potential energy to a one of low potential. It can only do so if there is a path for it to follow. This path is called an electric circuit. All circuit contain four elements: a source, a load, a transmission system and a control.
The source provides the electromotive force. This established the difference in potential which makes current flow possible. The source can be any device which supplies electrical energy. For example, it may be a generator or a battery.
The load converts the electrical energy from the source into some other forms of energy. For instance, a lamp changes electrical energy into light heat. The load can be any electrical device.
The transmission system conducts the current round the circuit. Any conductor can be part of a transmission system. Most systems consist of wires. It is often possible, however, for the metal frame of a unit to be one section on its transmission system.
The control regulates the current flow in the circuit. It may control the current by limiting it, as does a rheostat, or by interrupting it, as does a switch.
Grasshoppers
Of all the insects observed during this study, the spur-throated grasshoppers appear to cause the most damage to caragana in North Dakota. The three species of this group collected most prevalently were the two stripped grasshopper, the different grasshopper and the red-legged grasshopper.
The major identifying characteristics of the adult two-stripped species are two light tan stripes on the upper side which extend from the head to the wings tips. It is about 1-1/4 inches long. The differential grasshopper has the outer sides of the broad part of the hind legs marked with distinctive black bars arranged like chevrons; it is about 1-1/2 inches long. The red-legged grasshopper has bright red hind legs, is only ¾ inch long. Plain grasshopper usually feed on cereal grains and grasses, but they will feed on many species of trees and shrubs when their regular food is in short supply. L.F. Wilson noted that shelterbelt trees were fed upon and injured heavily only after field crops adjacent to the shelterbelts had been harvested. Since caragana commonly occupied the edge row, it was fed upon first and usually injured the most by defoliation and debarking.
Using Your Imagination
Scientist who has studied the behavior of animals tells us that one of the great differences between man and the lower animals are that man has the power of imagination. He can carry pictures and ideas in his mind and can rearrange and combine them to create new pictures and new ideas.
The power of imagination, like all of man’s powers, can, of course, be used for good or evil. If it is used to think of ways to harm others or to waste time in mere day-dreaming, it becomes evil or at least of doubtful value. If, on the other hand, it is used to invent machines or equipment that will help others, to produce works of art that will bring pleasure to others, or to deepen one’s own understanding of life, it is good.
Before you can use your imagination for good, however, you must develop it properly. You must supply it with pictures and ideas on which it can act; and you must motivate it so that it will act; and you must discipline it so that you can control the way it acts.