Gram staining. Gram staining or Gram stain, also called Gram's method, is a method of staining used to differentiate bacterial species into two large groups (gram-positive and gram-negative). The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique.
Horizon Oil Sands. Horizon Oil Sands The Horizon Oil Sands project (or Horizon) is an oil sands mining and upgrading project. Horizon is 100% owned and operated by Canadian Natural Resources Limited.
Horizon Services, Inc. is the heating and air conditioning authority in Delaware, Southeastern Pennsylvania, South New Jersey, and Northeastern Maryland. Get answers to some of the most commonly asked questions about heating and cooling equipment, energy efficiency, air quality and maintenance below.