Bulletin Board Ideas by Theme. Our Bulletin Board Ideas by Theme pages provide you with resources to help display your students' learning while keeping your classroom walls looking great all year long. Within each theme you will find fun and educational resources that are specific to the various topics covered within that theme. Several of the bulletin boards even include photos.
Background for the Kjeldahl determination of Organic Nitrogen. The Kjeldahl method is an analytical method for the determination of nitrogen in the trinegative state in certain organic compounds. The method was developed in 1883 by Johan Kjeldahl, a Danish chemist, and is used extensively in the determination of protein in foods, since protein is a macromolecule made up of nitrogen containing amino acids linked together.
These types of instruments are used by the wind energy industry, both for wind resource assessment and turbine control. Wind speed is measured with an anemometer. In situations where modern instruments are not available, an index finger can be used to test the direction of wind. This is accomplished by wetting the finger and pointing it upwards. The side of the finger that feels cool is (approximately) the direction from which the wind is blowing.