No description available.

Landfill biocovers have been proven as a green and efficient technology to mitigate landfill methane emissions. Thermal, hydraulic, mechanical and bio-chemical (THMBC) factors regulate biocover behaviour. The aim of the current study is to evaluate the geotechnical and geo-environmental response or performance of compost based biocovers under freeze-thaw conditions. A comprehensive experimental program, including tests on samples as well as biocover column experiments, has been conducted. The results demonstrate that the thermal properties (thermal conductivity and thermal diffusivity) of the biocovers change due to the FTCs. Moreover, the outcomes of the column experiments demonstrate that biocover performance remains at an acceptable level even after experiencing two FTCs despite that most of the THMBC parameters in the biocover have changed due to the impacts of the FTCs and methane injection. The findings presented in this thesis will contribute to a better understanding and design of compost biocovers in cold regions.

No description available.

Preservation of food by freezing is a common method of processing. Of relatively recent origin is the freeze-drying method. This method has several advantages over other methods of preservation, but is not free of problems, one of which is the maintenance of appearance and texture. In the present study, the effects of freezing, thawing, freeze-drying, and reconstitution on the physico-chemical properties of Northwest variety strawberries with particular reference to textural characteristics were investigated. Very little prior work is reported with regards to the effect of these factors on fruits. Strawberries were frozen at two different rates of freezing - slow frozen at 0°F and quick frozen in a blast freezer at -20°F. Frozen berries were examined by physical and chemical methods to evaluate the changes. In a separate study, berries were thawed under standard conditions of relative humidity and temperature and the drip collected for analysis. Thawed berries were examined by both physical and chemical methods. To study the reconstitution behaviour of the berries, they were freeze-dried and reconstituted under standard conditions of berry to water ratio, temperature of water and time of reconstitution. Reconstituted berries and the remaining solutions were then examined. Measurements of the texture, color, total solids, alcohol insoluble solids, pectins, cellulose, ash, and constituents of ash were made on raw, frozen, thawed, and reconstituted berries. The results indicated the following conclusions: 1. An increase in percent soluble solids, pH, and titratable acids and a decrease in total solids and AIS of the berries were observed upon freezing. Slow frozen berries showed more pronounced effects. Smaller berries were observed to change the least. No significant differences were found in the other constituents. 2. Strawberries lose weight upon thawing depending on the chemical composition of the berries. An inverse relationship was observed between weight loss and total solids, AIS, pectic substances, cellulose, ash and mineral content of the berries. With gradual increase in the weight loss upon thawing, there was a progressive softening of the berries. A direct relationship was found between weight loss and the amount of pectic substances, sugars, titratable acids, ash, and minerals found in the drip. Slow freezing resulted in higher weight loss and smaller berries lost the least. 3. A linear relationship exists between weight loss of the berries upon thawing and the area of the drip. This method offers a convenient and quick procedure for evaluation of the quality of frozen strawberries, with the added advantage of collecting the drip and storing it for further analysis at a convenient time. 4. Ability to reconstitute was found to be related to rate of freezing and size of berry. Quick freezing and smaller berries gave the best results. 5. Direct relationship was found between the degree of reconstitution and total solids, AIS, pectic substances, cellulose, ash, and minerals. The amount of pectic substances, sugar, titratable acids, ash, and minerals leaching out of the berries into the reconstituting solution were smaller and were independent of the degree of reconstitution. 6. Individual berries showed a large variation in their chemical constituents, which was responsible for the differences in the thawing and reconstitution behavior of Northwest strawberries. / Graduation date: 1967

Graduation date: 1972

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1948. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves [76]-77.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 82-84). Also available via the Internet.

Thesis (Ph.D.)--Boston University / One of the more powerful and consistent tools available to nature is the phenomenon of alternate freezing and thawing. Mechanically, extraordinary pressures may be involved because of the density differential existing between the liquid wnd the solid phases of water. Physiologically, there is the availability or nonavailability of water to sustain growth. Despite this, catastrophic changes are not to be expected. On the other hand, such a powerful tool must leave its imprint in one manner or another upon the natural landscape. In most arctic and highland areas the imprint is directly discernible. In more moderate climes the imprint is indirectly applied principally as a limiting parameter within an aggregate of generally favorable conditions. The phenomenon of freeze-thaw is a climatic parameter but not a climatic element. Unlike the elements, there is a definite threshold involved; that is, 32° Fahrenheit or 0° Centigrade. At this threshold water may exist in either the liquid or solid state but by the addition or subtraction of heat it can change from one state to the other without a gain or loss in temperature. In the natural environment the terms are not quite so precise. Time for the process to take place, impurities in the water, and the variation of temperature regimes among the many nooks and crannies of the landscape point to the necessity of relaxing the temperature threshold. In this study the zone of 34° F and 28° F is used. Conditions favorable for a thaw are thought to occur when: the temperature rises through the zone and conditions favorable for a freeze when the temperature drops through this zone [TRUNCATED].

Landfill biocovers have been proven as a green and efficient technology to mitigate landfill methane emissions. Thermal, hydraulic, mechanical and bio-chemical (THMBC) factors regulate biocover behaviour. The aim of the current study is to evaluate the geotechnical and geo-environmental response or performance of compost based biocovers under freeze-thaw conditions. A comprehensive experimental program, including tests on samples as well as biocover column experiments, has been conducted. The results demonstrate that the thermal properties (thermal conductivity and thermal diffusivity) of the biocovers change due to the FTCs. Moreover, the outcomes of the column experiments demonstrate that biocover performance remains at an acceptable level even after experiencing two FTCs despite that most of the THMBC parameters in the biocover have changed due to the impacts of the FTCs and methane injection. The findings presented in this thesis will contribute to a better understanding and design of compost biocovers in cold regions.