Microwave tempering experiments were conducted on frozen blocks of shrimp (FSB) and the results were used to help determine if microwave tempering of FSB is an improved thawing method over the current, traditional method, water immersion. Results of the microwave tempering experiments were also used to help determine which microwave tempering method amongst those explored by this study is most effective. Complete thawing of a FSB in a microwave oven was found to be impractical; however, using a combination of microwave tempering followed by water immersion can successfully thaw a FSB. After a microwave tempering experiment was conducted, the final stages of thawing were completed by using the traditional water immersion method. The amount of time to complete the thawing was recorded and is referred to as the additional thawing time. The amount of shrimp cooked during microwave tempering was also recorded and calculated as a percent. The additional thawing time and the percentage of shrimp cooked were used as criteria to compare microwave tempering experiments and also to compare microwave tempering experiments with the current method. The first set of microwave tempering experiments explored the advantages of freezing a microwave susceptive material within the FSB before microwave tempering. FSBs with susceptors and FSBs without susceptors were tempered in a microwave oven. The FSBs were tempered in a 2450 MHz microwave oven at 255 W for 35 minutes and at 406 W for 22 minutes. The results showed that the addition of susceptors does improve the microwave tempering process. The percentage of cooked shrimp and the additional thawing time was less for FSBs with susceptors than for FSBs without susceptors. The susceptors seem to help distribute the microwave energy more evenly, which reduces runaway heating and in turn reduces the amount of shrimp cooked. When compared to the current method, microwave tempering with susceptors reduced the total thawing time by 45% while microwave tempering without susceptors reduced the total thawing time by 43%. Both microwave tempering methods, with and without susceptors, are an improvement over the current method. The addition of susceptors does improve the microwave tempering process; however, the improvements are not significant enough to justify its recommendation. The second set of microwave tempering experiments explored the advantages of pulse microwave tempering. During pulsed microwave tempering the microwave oven was set to a high power level and was turned ON for a period of time and then OFF for a period of time. The ON/OFF pattern was repeated throughout the microwave tempering process. Several pulsed tempering experiments were conducted at a microwave power level of 848 W and at a microwave power level of 993 W. The results showed that there is no significant advantage to using pulsed microwave energy during tempering as opposed to continuous, fixed microwave energy. The results showed that fixed microwave tempering is more effective than pulsed microwave tempering. The percentage of cooked shrimp was lower for fixed experiments than for pulsed experiments and the additional thawing time was slightly less for fixed experiments than for pulsed experiments. A mathematical model was developed to help predict he temperature profiles of a FSB during microwave tempering. Experimental temperature data were collected at four locations within the FSB during microwave tempering by using four Luxtron Fluoroptic temperature probes and a Luxtron Fluoroptic thermometer. Overall, the temperatures predicted by the model were within 2 oC of the experimental temperatures. After the first 500 seconds or so of microwave tempering, the temperatures predicted by the model were consistently less than the experimental temperatures. From this study it was determined that the most effective microwave tempering method, amongst those conducted in this study, of a 2.2 kg (5 lb) frozen block of shrimp was accomplished by setting the power output to 255 W and the microwave cooking (tempering) time to 35 minutes. As previously mentioned, the addition of susceptors does improve the process but the improvements are not significant enough to justify its recommendation. Pulse tempering is not an improved method over fixed tempering. / Master of Science

Shading devices have the potential to reduce peak cooling load and annual energy consumption because they can be used to control solar gain. Thus, the need to model shading devices in a glazing system analysis is important. This thesis deals with various measurement techniques and model development related to solar optics in windows with shading devices. It also considers longwave radiative properties of shading devices via model development and experimentation. The different shading devices examined were roller blinds, insect screens, pleated drapes and venetian blinds. The energy performance of windows with shading devices was modeled using a two step procedure. Solar radiation was considered in the first step by developing a multi-layer solar optical model for glazing/shading systems. This newly developed model is an extension of an existing model for systems of specular glazing layers and includes the effect of layers that create scattered, specifically diffuse, radiation in reflection and/or transmission. Spatially-averaged (effective) optical properties were used to characterise shading layers, including their beam-diffuse split. The multi-layer solar optical model estimates the system solar transmission and absorbed solar components. The absorbed solar components appear as energy source terms in the second step – the heat transfer analysis. The heat transfer analysis involves the formulation of energy balance equations and requires both effective longwave properties and convective heat transfer coefficients as input. The simultaneous solution of the energy balance equations yields the temperature as well as the convective and radiative fluxes. The effective solar optical properties of flat materials like drapery fabrics, roller blinds and insect screens were obtained by developing a new measurement technique. Special sample holders were designed and fabricated to facilitate measurements using an integrating sphere installed in a commercially available spectrophotometer. Semi-empirical models were then developed to quantify the variation of solar optical properties with respect to incidence angle. In turn, effective layer properties of venetian blinds and pleated drapes were modeled using a more fundamental net radiation scheme. The effective longwave properties of flat materials were obtained by taking measurements with an infrared reflectometer using two backing surfaces. The results enabled simple models to be developed relating emittance and longwave transmittance to openness, emittance and longwave transmittance of the structure. In turn, effective longwave properties of venetian blinds and pleated drapes were modeled using a net radiation scheme. Convective heat transfer correlations were readily available. Finally, the newly developed models were validated by measuring the solar gain through various shading devices attached to a double glazed window using the National Solar Test Facility (NSTF) solar simulator and solar calorimeter. Solar gain results were also obtained from simulation software that incorporated the models. There was good agreement between the measured and the simulated results thus strengthening confidence in the newly developed models.

Shading devices have the potential to reduce peak cooling load and annual energy consumption because they can be used to control solar gain. Thus, the need to model shading devices in a glazing system analysis is important. This thesis deals with various measurement techniques and model development related to solar optics in windows with shading devices. It also considers longwave radiative properties of shading devices via model development and experimentation. The different shading devices examined were roller blinds, insect screens, pleated drapes and venetian blinds. The energy performance of windows with shading devices was modeled using a two step procedure. Solar radiation was considered in the first step by developing a multi-layer solar optical model for glazing/shading systems. This newly developed model is an extension of an existing model for systems of specular glazing layers and includes the effect of layers that create scattered, specifically diffuse, radiation in reflection and/or transmission. Spatially-averaged (effective) optical properties were used to characterise shading layers, including their beam-diffuse split. The multi-layer solar optical model estimates the system solar transmission and absorbed solar components. The absorbed solar components appear as energy source terms in the second step – the heat transfer analysis. The heat transfer analysis involves the formulation of energy balance equations and requires both effective longwave properties and convective heat transfer coefficients as input. The simultaneous solution of the energy balance equations yields the temperature as well as the convective and radiative fluxes. The effective solar optical properties of flat materials like drapery fabrics, roller blinds and insect screens were obtained by developing a new measurement technique. Special sample holders were designed and fabricated to facilitate measurements using an integrating sphere installed in a commercially available spectrophotometer. Semi-empirical models were then developed to quantify the variation of solar optical properties with respect to incidence angle. In turn, effective layer properties of venetian blinds and pleated drapes were modeled using a more fundamental net radiation scheme. The effective longwave properties of flat materials were obtained by taking measurements with an infrared reflectometer using two backing surfaces. The results enabled simple models to be developed relating emittance and longwave transmittance to openness, emittance and longwave transmittance of the structure. In turn, effective longwave properties of venetian blinds and pleated drapes were modeled using a net radiation scheme. Convective heat transfer correlations were readily available. Finally, the newly developed models were validated by measuring the solar gain through various shading devices attached to a double glazed window using the National Solar Test Facility (NSTF) solar simulator and solar calorimeter. Solar gain results were also obtained from simulation software that incorporated the models. There was good agreement between the measured and the simulated results thus strengthening confidence in the newly developed models.