growth additives
51Cement — In the most general sense of the word, a cement is a binder, a substance which sets and hardens independently, and can bind other materials together. The name cement goes back to the Romans who used the term opus caementicium to describe masonry… …
52Fishkeeping — is a popular hobby concerned with keeping fish in the home aquarium or garden pond. Types of fishkeeping The hobby can be broadly divided into three specific disciplines, freshwater, brackish, and marine (also called saltwater) fishkeeping.… …
53Aquarium — An aquarium (plural aquariums or aquaria ) is a vivarium consisting of at least one transparent side in which water dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, and aquatic… …
54nitrogen group element — ▪ chemical elements Introduction any of the chemical elements that constitute Group Va of the periodic table (see Figure >). The group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb), and bismuth (Bi). The elements share… …
55organosulfur compound — ▪ chemical compound Introduction also spelled organosulphur compound , also called organic sulfur compound a subclass of organic substances that contain sulfur and that are known for their varied occurrence and unusual properties. They are… …
56Agriculture and Food Supplies — ▪ 2007 Introduction Bird flu reached Europe and Africa, and concerns over BSE continued to disrupt trade in beef. An international vault for seeds was under construction on an Arctic island. Stocks of important food fish species were reported… …
57Carbon nanotube — Not to be confused with Carbon fiber. Part of a series of articles on Nanomaterials Fullerenes …
58Calcium carbonate — Calcium carbonate …
59Octane rating — or octane number is a standard measure of the anti knock properties (i.e. the performance) of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand before detonating. In broad terms, fuels with a… …
60Jet fuel — An Airbus A310 being fueled at Prague Airport Jet fuel is a type of aviation fuel designed for use in aircraft powered by gas turbine engines. It is clear to straw colored in appearance. The most commonly used fuels for commercial aviation are… …
