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.
3. soup sandwich. A term used in the US Army to denote extreme uselessness. It is directed toward something or someone that is the figurative equivalent of the literal hot sloppy pile of shit that a gob of soup between two pieces of sandwich bread would be. So the implication here is that the object of discussion is 'Fucked up like a soup sandwich.'.