Fowl cholera immunization in turkeys. II. Use of experimental epornitic method to study vaccine efficacy in flocks of turkeys.
Groups of turkeys were challenged with Pasteurella multocida (P-1059) by the contact method. In this method, turkeys are artificially infected by the intramuscular injection of P. multocida organisms and are then introduced into the test group. The death patterns resulting from this contact method of challenge are either normally distributed or skewed to the right.
Fowl cholera in turkeys--the efficacy of adjuvant bacterins.
Ever since the production of the classical attenuated fowl cholera vaccine by Pasteur, many attempts have been made to prevent outbreaks of fowl cholera in chickens. His method could not be duplicated successfully, however, and a search for a more dependable method in controlling the disease effectively has been conducted since the early 1920's. The effectiveness of earlier aqueous avirulent vaccines (7) and bacterins (13) has always been variable (8,19,9,10). Carter (2) compared the immune response in mice to bacterins made from broth cultures and chicken embryo vaccines made from Pasteurella multocida, type A. Chicken embryo vaccine was much superior to broth-derived bacterin in immunizing value. Bierer et al. (1) described a phenol-killed autogenous bacterin which afforded some protection to turkeys in an infected flock. The challenge, however, was carried out within 20 days of vaccination.
Accurate measurements of output characteristics and detonations of motorbike high-speed racing engine and their optimization at actual atmospheric conditions and combusted mixture composition
Abstract At a motorbike high speed racing engine there is very important an output engine characteristics which depends significantly on a detonation combustion rate, atmospheric conditions and a combusted mixture composition. The combustion process has got a relevant influence on a wear degree of main engine parts or on their damage eventually. The detonation combustion rate is very important because this kind of burning can be not only destructive but a useful phenomenon, as well. If the process of detonation burning is kept on a certain level, it can help significantly to the next increasing of an engine power output. In this article there is described the measurements of output characteristics of a high-speed racing engine which were performed by means of a data-recording system and the detonation combustion was evaluated using a quantitative method. The actual values of atmospheric conditions and the mixture composition were added to the measured values. Then the obtained values are compared visually with a damage degree of an engine piston caused by the detonation burning. The result is a limit value expressed in a number of detonation units related to a run distance interval of the vehicle driven by the high-speed racing engine. In framework of this run distance interval there is the process of detonation burning profitable. As well as it increases an engine power output and together it is not destructive with regard to engine design parts.