Bratwurst Bucyrus, Ohio (which calls itself the "Bratwurst Capital of America") has held the three-day Bucyrus Bratwurst Festival annually since 1967. Bratwurst Bratwurst () is a type of German sausage made from veal, beef, or most commonly pork. The name is derived from the Old High German "Brätwurst", from "brät-", finely chopped meat, and "Wurst", sausage, although in modern German it is often associated with the verb "braten", to pan fry or roast. While sausage recipes can be found as early as 228 AD, the first documented evidence of the "Bratwurst" in Germany dates to 1313 and can be found in
Slowly varying envelope approximation assumptions which are made need to be justified. For example, consider the electromagnetic wave equation: If k and "ω" are the wave number and angular frequency of the (characteristic) carrier wave for the signal "E"(r,"t"), the following representation is useful: where formula_3 denotes the real part of the quantity between brackets. In the "slowly varying envelope approximation" (SVEA) it is assumed that the complex amplitude "E"(r, "t") only varies slowly with r and "t". This inherently implies that "E"(r, "t") represents waves propagating forward, predominantly in the k direction. As a result of the slow variation of "E"(r, "t"), when