Fields of Anthropology. There are now four major fields of anthropology: biological anthropology, cultural anthropology, linguistic anthropology, and archaeology. Each focuses on a different set of research interests and generally uses different research techniques.
SPC is one of the three categories of Statistical Quality Control (SQC). SQC is a statistical method of analyzing variations in the manufacturing process in order to make it better and more effective. Only a certain number of samples are needed to determine whether the products are acceptable.
What is an STC Rating? STC stands for Sound Transmission Class. Basically, STC ratings are an established way to average how much sound is stopped by something. STC ratings are used for windows, doors, walls and most building materials. For windows, STC ratings range from 18 to 38. STC ratings are the ONLY way to accurately compare various noise reduction products. An STC rating is an instrument measurement of how much noise is stopped. The STC ratings allow accurate âapple to appleâ comparisons. The STC rating is the average amount of noise stopped at 18 different frequencies, measured in decibels.