The purpose of this study was to evaluate the applied use of a commercial UV unit for air sanitation in the cold storage rooms of a local supermarket chain. On-site testing was performed in four supermarkets (two control stores without UV units and two experimental stores) and one warehouse employing UV units. Meat processing, meat storage, and produce storage rooms were randomly sampled by the open plate and swab methods. Commonly occurring "representative microorganisms" were then selected and identified as Pseudomonas sp., Flavobacterium sp., Bacillus sp., Rhodotorula sp., and Penicillium sp. which were taken into the laboratory for UV testing. Representative microorganisms were effectively killed by UV when tested in the laboratory. Exposure to UV was conducted on agar streaked plates and aerosol suspensions of the microorganisms. The effectiveness of the commercial UV unit in the applied setting was less easily determined due to a complexity of changing variables between rooms and between stores. In general, the UV unit appeared to be of noticeable benefit where airborne yeasts and molds were predominant. This occurred in produce rooms. Regular maintenance of the UV unit was necessary for maximum efficiency. The meat processing room presented unique problems relating to procedural habits of the personnel. In all supermarket cold rooms, good "housecleaning" remained the key to controlling microorganisms.Ball State UniversityMuncie, IN 47306

No description available.

Thesis (MTech (Electrical Engineering))--Peninsula Technikon, 2002 / This research outlines the development and design of an infrared radiation heating profile controller. The study includes both the theoretical aspects of the design process as well as giving an overview of the practical facets involved. The controller was subjected to comparative testing with a proportional control model, in order to observe its performance and validate its effectiveness. A need exists for these types of controllers and proved to be the motivation to embark on this investigation. Controllers of this nature that are commercially available either lacks the functionality of this unit or are too expensive to implement for research purposes. This unit was designed with cost effectiveness in mind but still meet the standards required of an industrial style controller. To this end the construction was completed using low cost and affordable electronic components. Heating profiles are necessary and useful tools for the proper processing of a host of materials. The controller developed in this research is able to within a fair degree of accuracy track a heating profile. The results confirm that this programmable control model to be a benefit and a valuable tool in temperature regulation. This means that intensive studies into the effects of infrared radiation on materials are now feasible. Research of this nature could possibly expand the application of infrared as a heating mechanism. Although tests were conducted on this controller, they are not meant to serve as an exhaustive analysis. The conclusions of these examinations do reveal the benefit of such a controller. More rigorous investigation is suggested as a subject for further study.