Surface combustion burners or radiant tile burners in comparison produce nitrogen oxides' levels 60-70% less. Therefore John Joyce's research into low NO x burners revolved primarily around surface combustion techniques. Another issue was the effect combustion temperatures have on the formation of NO x.
soup sandwich. A slang term used by members of the United States Army to describe a fellow soldier whose performance is unsatisfactory. This term is often shortened to just soup.. The term expresses a state of extreme uselessness, which can be understood by considering the functionality and worth of soup between two slices of bread.
Why it works: This pairing combines two Italian classics: minestrone soup and a muffuletta sandwich. Piled high with texture and layers, this chicken sandwich is the star, and the veggie-packed, tomato-based minestrone is the perfect accompaniment. Soup: Slow-Cooker Beef-Tortellini Soup.