the COB and set it on preheat. Run the temperature up to 

 600°F and recirculate the CA room atmosphere through 

 the generator. The temperature of the catalyst may rise, 

 and if ^vill remain hot until the combustible gas (propane 

 or natural gas) is down to a s£ife level. 



-Some storage operators routinely use a COB to scrub 

 out any combustible gas which may have entered a CA 

 room during pulldown. 



It is possible to reduce risks to a minimum. By 

 understanding the principles of CA generator operation, 

 maintaining the equipment and safety devices, and using 

 the available instrumentation, managers can maintain a 

 clean and safe storage atmosphere. 



Reprinted from Postharvest Pomology Newsletter, Wash- 

 ington State University, March, 1988. 



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An "Expert System" for CA Storage of Mcintosh Apples 



William J. Bramlage 



Department of Plant & Soil Sciences, University of Massachusetts 



Our recent survey of CA storage operators in Massa- 

 chusetts indicated that many storages are not being oper- 

 ated at conditions that are most suitable for Mcintosh 

 apples. Factors that can contribute to this situation include 

 not recognizing the importance of certain conditions, or 

 overlooking details during the hectic harvest period. 



To try to provide easy access for storage operators to 

 critical information, and to create a mechanism for self- 

 evaluation of storage operations, we are developing an 

 "Expert System" for CA storage of Mcintosh apples in 

 New England. This system is a series of questions, with 

 answers to be provided by the storage operator, followed by 

 advice about how long the apples reasonably can be ex- 

 pected to retain quality in storage, the potential for storage 

 disorders resulting from some adverse storage condition, 

 and corrections that might be made when an adverse 

 condition is recognized. 



This "Expert System" is a computer program on a 

 floppy disk that can be operated on any IBM-compatible 

 personal computer. It will come with directions for activat- 

 ing and operating the program, and will require only the 

 availability of an IBM"^-compatible personal computer 

 with 640 kbyte memory capacity, and the rudimentary 

 knowledge for operating the computer. 



This system was developed by A. Zubin Varghese, a 

 graduate student in our Department of Food Engineering, 

 through a series of intense interviews with the author. Mr. 

 Varghese worked with Ernest Johnson and Lester Whit- 

 ney, in the Department of Food Engineering, to convert the 

 information from these interviews into a computer pro- 

 gram. This Expert System depicts the author's best judg- 

 ment of CA storage conditions for Mcintosh apples in 

 Massachusetts, but in a broader sense provides informa- 



tion about storage responses of apples to varying condi- 

 tions. Its format is a series of "If ... Then ..." situations and 

 its primary goal is to provide information to help reduce 

 losses of apples during and following storage. 



The questions in this program first attempt to establish 

 the potential of a set of apples for storage based on maturity 

 at harvest, speed of cooling, time required to fill and seal a 

 CA room, and time required to generate the CA atmos- 

 phere. Then, the storage operator is questioned about the 

 conditions that are being maintained within the CA room, 

 including unintended deviations from recommendations. 

 Where less-than-desired conditions exist, suggestions for 

 "what might have been" are given. Where risks of physio- 

 logical disorders are recognizable, these risks are quanti- 

 fied, the potential disorder is described, and possible 

 corrective actions are recommended. The program is 

 accompanied by a printed text describing the kinds of 

 information needed to answer the questions, and the 

 recommended ways of obtaining this information. 



This "Expert System" is new and needs testing to see 

 how useful it is and how it might be improved. It is primarily 

 intended as an educational tool, a readily available source 

 of information. We hope to have it available for trial by late 

 summer, and to offer it through the University of Massa- 

 chusetts Cooperative Extension for a small fee to cover 

 expenses. 



We hope that some CA storage operators will be 

 willing to try the system and to help us evaluate its useful- 

 ness and possible improvements. If you are interested in 

 obtaining and evaluating this "Expert System" if it is 

 available by late summer, please contact the author or Dr. 

 Wesley Autio, at your earliest convenience. 



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