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Experiments have been carried out in order to investigate the stabilization of water temperature with a water-PCM heat exchanger. The water-PCM heat exchanger was of a rather simple design. It was a round tube, through which the water flowed, surrounded with an annular layer of PCM. The heat exchanger was divided into one meter long segments (modules) and the water temperature was monitored at the outlet of each of the segments. A paraffin-based PCM with the melting temperature of 42 °C was used in the experiments. The experimental set-up consisted of two water reservoirs kept at different temperatures, the water-PCM heat exchanger, PC controlled valves and a data acquisition system. As the first step a response to a step change in the water temperature at the inlet of the heat exchanger was investigated. Subsequently, a series of experiments with a square wave change of temperature at the inlet of the exchanger were carried out. The square wave temperature profile was achieved by periodic switching between the two water reservoirs. Several amplitudes and periods of temperature square wave were used. The results of experiments show that a water-PCM heat exchanger can effectively be used to stabilize the flowing water temperature when the inlet temperature changes are around the melting range of the PCM. [ABSTRACT FROM AUTHOR]

Data regarding actual wealth, assets, and net worth of individuals are rarely available, however, probate records in Iowa offer a, perhaps, unique opportunity to measure and examine actual wealth and factors that influence it. This research examines the influence of gender and locational context on wealth inequality at death. The analysis utilizes individual estate value information from more than 50,000 probate records of decedents in Iowa. The estate values are calculated from estate fees assessed in Iowa that are proportional to the size of the estate and are part of the public record. The findings show that menis average estate size is larger than that for women, both statewide and in a majority of the counties. These findings contrast with conventional wisdom which suggests that women, because of longer life expectancy and outliving their husbands, have a majority of the wealth when they die. The largest differences in average wealth, however, are not by gender but by county location. Findings show that the average estate values across the counties have a positive relationship with land values, income levels, and educational levels, and a negative relationship with poverty levels. Both male and female decedents from counties with historically lower incomes and lower land and housing values, have smaller estates, on average, than those from counties with higher income and higher land and housing values. This suggests that it is life-long access to resources and income that contributes the most to wealth and wealth inequality at death. [ABSTRACT FROM AUTHOR]

The paper deals with experimental investigations of the performance of a solar air collector with latent heat thermal storage integrated with the solar absorber. The main purpose of heat storage in solar thermal systems is to store heat when the supply of solar heat exceeds demand and release it when otherwise. A number of heat storage materials can be used for this purpose; the phase change materials among them. Short-term latent heat thermal storage integrated with the solar absorber can stabilize the air temperature at the outlet of the collector on cloudy days when solar radiation intensity incident on a solar collector fluctuates significantly. Two experimental front-and-back pass solar air collectors of the same dimensions have been built for the experimental investigations. One collector had a "conventional" solar absorber made of a metal sheet while the solar absorber of the other collector consisted of containers filled with organic phase change material. The experimental collectors were positioned side by side during the investigations to ensure the same operating conditions (incident solar radiation, outdoor temperature). [ABSTRACT FROM AUTHOR]

Simulations of the behaviour of a solar air collector with integrated latent heat thermal storage were performed. The model of the collector was created with the use of coupling between TRNSYS 17 and MATLAB. Latent heat storage (Phase Change Material - PCM) was integrated with the solar absorber. The model of the latent heat storage absorber was created in MATLAB and the model of the solar air collector itself was created in TRNSYS with the use of TYPE 56. The model of the latent heat storage absorber allows specification of the PCM properties as well as other parameters. The simulated air collector was the front and back pass collector with the absorber in the middle of the air cavity. Two variants were considered for comparison; the light-weight absorber made of sheet metal and the heat-storage absorber with the PCM. Simulations were performed for the climatic conditions of the Czech Republic (using TMY weather data). [ABSTRACT FROM AUTHOR]

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