Typescript, etc. / Digitized by Kansas State University Libraries

The purpose of this research was to develop three real-time adaptive temperature controllers for hyperthermia heating systems. Each scheme is made adaptive by using a transient Gaussian estimation routine to estimate the tissue blood perfusion and by then using these estimated values either in an optimizing routine, or in an observer, or in both. The optimizing routine uses a steady-state Gaussian estimation technique to optimize the power distribution until the best possible match is obtained between the steady-state temperatures predicted by a treatment model and a prespecified ideal temperature distribution. The observer uses a treatment model to control unmeasured locations. The first adaptive control scheme uses the optimizing routine alone, the second uses the observer alone and the third uses both the optimzing routine and observer. The performance of each of the adaptive control schemes is compared to a standard proportional-integral-derivative (PID) control scheme for one-dimensional simulations of typical treatments. Results comparing the deviation of the controlled temperature distribution to the ideal desired temperature distribution for all locations and all times indicate that the adaptive schemes perform better than the PID scheme. It can be concluded that adaptive control yields improved performance if good a priori knowledge of the treated region tissue and perfusion region boundaries is available. While these control schemes were designed for eventual implementation on a scanned focused ultrasound hyperthermia treatment system, the techniques are applicable to any system with the capability to vary specific power with respect to location and with an unknown distributed energy sink proportional to the temperature elevation.

published_or_final_version / abstract / Conservation / Master / Master of Science in Conservation

Since vegetables are of such importance in the nutrition of human beings, it is natural that they should play a large part in Army feeding. They are high in food value. The different kinds vary widely in their energy values; some-- like potatoes--are high in carbohydrates, others--like lettuce and cucumbers-- are low. Fresh or canned they are high in minerals and vitamins, low in protein and fat, and are valuable for bulk and palatability. When purchasing fresh produce it was necessary to know something of quality, appearance, and texture. Quality is made up of many characteristics-- some external, internal, chemical, and physical. Appearance is concerned with shape, color, freedom from blemishes and dirt. Texture contrasts hard or soft, smooth or granular, stringy and fibrous or free from fiber, crisp or flabby, wilted or tough. The flavor of vegetables is due to several constituents: sugar, organic acids, mineral salts, and aromatic compounds. A combination of these gives flavors that make vegetables palatable and attractive. The nutritive value of a given vegetable depends on the part of the plant to be used, as well, as the variety, climate, soil in which it is grown, conditions of storage, and preparation. The leaf, stem, flower, seed, and fruit are all edible parts. When purchasing vegetables for the Army it was well to know that the initial price was by no means the ultimate cost as there was a wide margin between the cost as purchased and edible-portion cost. Waste in preparation, storage, and losses in the cooking of highly perishable produce would cost six cents per pound as purchased and thirty cents per pound edible portion. The condition of the vegetables when delivered has a great influence on the probable yield. When purchasing canned vegetables, grades were used as purchasing guides. Samples of each grade of produce were requested for testing to find out if the product was satisfactory. The highest grade was not purchased for general use; Grade B or Standard was acceptable for the Army mess. Fresh and frozen vegetables were used largely in Army camps and fields in the United States. Canned and dehydrated products were to be used in combat areas overseas because they were easy to prepare, there was little or no waste, and the nutritive value was fairly well retained. The problem of storage was not difficult, and shipping space was saved when dehydrated food was shipped because of its lightness and lack of bulk. The Army food purchasing officer needed to be familiar with the local vegetable supply and market center facilities. A knowledge of standardizing, grading, packaging, sorting, and transporting produce was necessary in order to purchase food economically and intelligently. Because of uncertainty of crops due to curtailed planting and harvesting occasioned by labor shortages, it was difficult for producers and distributors to cooperate at all times. The Quartermaster's office arranged with local marketing centers for information on prices, substitutions, and quantities of local produce available, several days in advance, so that suitable substitutions could be made on menus if sufficient fresh vegetables were not obtainable. Inspection of all food on delivery was required, and if low grade or unsatisfactory produce was discovered it was returned to the dealers or an adjustment requested. This was done to determine whether or not supplies met the contract requirements for quality and conditions specified by the Army. / Graduation date: 1947

Cook-Chill Foodservice System was a new alternative foodservice system in the 1960s. Food items in Cook-Chill Foodservice Systems are prepared and chilled in advance of service, stored in inventory, and then rethermalized before consumption. The purpose of this research was to evaluate Cook-Chill Systems from the foodservice manager's view. The objectives of this study were to: (1) identify effects, advantages and disadvantages, and decision making factors for selection Cook-Chill Systems as perceived by managers, and (2) determine if the demographics influence managers' assessment. A survey questionnaire was used to collect current information of Cook-Chill Systems. One hundred thirty-four surveys were mailed nationwide to foodservice managers with 95 (71%) valid responses. Data were analyzed from the 74 respondents who currently used Cook-Chill Systems. The results indicated that the perceived meal quality, quantity control and personnel satisfaction was equal or better, and labor cost was decreased and equipment cost increased were most often reported by managers in comparing Cook-Chill Systems with prior systems. Managers identified seven advantages: good working conditions, high productivity, labor savings, consistent quality food, good quantity control, nutrient retention, and safety. One perceived disadvantage was high capital cost of equipment. The five most often cited factors for selection of Cook-Chill Systems were labor savings, good working conditions, consistent quality food, safety, and high productivity. Factors most often cited for not selecting Cook-Chill Systems were the limited menu and types of products produced, complaints of bad food, and high capital cost. Most Cook-Chill Systems have been installed in the past ten years with previously centralized production flow. Cook-Chill Systems accommodated small to large numbers of meals with both blast chiller and tumbler chiller equipment and many reheating methods. Half of the managers were involved in choosing, designing or implementing Cook-Chill Systems. Four significant outcomes were: (1) microbiological control was the highest of meal quality contributes; (2) manager satisfaction was higher than customer and employee satisfaction; (3) meal quality and personnel satisfaction differed among reheating methods; and (4) management experience for design or implementation influenced managers' willingness in choosing these systems again. Four recommendations were drawn from this research. Recommendations were: (1) studies to identify factors contributing to success of reheating methods, (2) standard models for cost recording, (3) approaches to analyze capital cost, create menu items, and find causes of food quality complaints, and (4) a Cook-Chill Information Center to share knowledge and support the further development of Cook-Chill Systems. / Graduation date: 1991

No description available.

No description available.

Light can be coupled out of a waveguide to a focused point by a focusing grating coupler and has possible applications in optical data storage. The grating can be fabricated with either e-beam techniques or holographic techniques. Two design methods are demonstrated that model the focusing grating coupler with holographic optical elements. Both methods take a geometrical optics approach to designing the holographic optical elements and both methods make use of commercially available ray trace programs. The first method uses complicated non-rotationally symmetric construction optics and requires either a modified ray trace program or special user defined surfaces. The second method involves a much simpler approach which did not require any changes to an existing ray trace program and requires only rotationally symmetric elements to correct the aberrations.

No description available.

No description available.