Food Some cultures consume blood, sometimes in the form of blood sausage, as a thickener for sauces, or in a cured, salted form for times of food scarcity, and others use blood in stews such as jugged hare. Some cultures and people do not consume meat or animal food products for cultural, dietary, health, ethical, or ideological reasons. Vegetarians choose to forgo food from animal sources to varying degrees. Vegans do not consume any foods that are or contain ingredients from an animal source. Adulteration is a legal term meaning that a food product fails to meet the legal standards. One
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