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.
A sling psychrometer is a common instrument used by meteorologists to determine the relative humidity. This instrument is swung around while being held. There are also a variety of other humidity sensors which work automatically to measure the water content and relative humidity of the atmosphere. wind vane is used as part of the anemometer to determine the wind's direction. As the wind flows over the windmill, the speed and direction of the wind can be measured with this instrument. Some scientific anemometers use the speed of sound to measure the wind speed more precisely in three dimensions.