Simulation and evaluation of latent heat thermal energy storage

The relative value of thermal energy storage (TES) for heat pump storage (heating and cooling) as a function of storage temperature, mode of storage (hotside or coldside), geographic locations, and utility time of use rate structures were derived. Computer models used to simulate the performance of a number of TES/heat pump configurations are described. The models are based on existing performance data of heat pump components, available building thermal load computational procedures, and generalized TES subsystem design. Life cycle costs computed for each site, configuration, and rate structure are discussed

Consumer Perceptions of Organic, Natural, and Conventional Products When Provided at the Same Price.

Today’s grocery stores are filled aisle to aisle with an overwhelming variety of options for the consumer. In a consumer-driven market structure, the food industry has grown to encompass many niche markets which meet the ever changing demands of consumers. From organically produced food to more modern agriculture practices and even to finding non-meat protein alternatives, the options are endless. However, in the United States (a country with a higher level of disposable income compared to others), the question arises are customers educated about what the products truly are that they are spending a price premium on? This study assessed the perceptions that college students have regarding the labeling terms organic and natural – specifically in regards to the poultry industry. Through a focus group interview process and administration of a brief survey questionnaire, data was collected surrounding the various perceptions. The collected data was analyzed using the constant comparative method and NVivo software to arrive at common themes amongst respondents. The results found in general consumers believe organic and natural to be synonymous terms that are both equated to a “cleaner,” “healthier” product. Although most respondents placed heavy emphasis on the influence of price to their current buying decisions, if all three (organic, natural, and conventional) otherwise identical products were offered at the same price, they would gravitate towards either the organic or natural option. After presenting respondents with the technical definitions, there was a shift away from natural products and a newfound interest in what other food labels mean. This solidified the importance for strengthened agriculture communication and proved consumers do like to be knowledgeable about their food, they just may not know where to find accurate information. Future research should evaluate broader demographic populations and look further into what methods of education would be most beneficial

Southwest Research Institute assistance to NASA in biomedical areas of the technology utilization program

The activities are reported of the NASA Biomedical Applications Team at Southwest Research Institute between 25 August, 1972 and 15 November, 1973. The program background and methodology are discussed along with the technology applications, and biomedical community impacts

Why do leaf-tying caterpillars abandon their leaf ties?

Leaf-tying caterpillars act as ecosystem engineers by building shelters between overlapping leaves, which are inhabited by other arthropods. Leaf-tiers have been observed to leave their ties and create new shelters (and thus additional microhabitats), but the ecological factors affecting shelter fidelity are poorly known. For this study, we explored the effects of resource limitation and occupant density on shelter fidelity and assessed the consequences of shelter abandonment. We first quantified the area of leaf material required for a caterpillar to fully develop for two of the most common leaf-tiers that feed on white oak, Quercus alba. On average, Psilocorsis spp. caterpillars consumed 21.65 ± 0.67 cm2 leaf material to complete development. We also measured the area of natural leaf ties found in a Maryland forest, to determine the distribution of resources available to caterpillars in situ. Of 158 natural leaf ties examined, 47% were too small to sustain an average Psilocorsis spp. caterpillar for the entirety of its development. We also manipulated caterpillar densities within experimental ties on potted trees to determine the effects of cohabitants on the likelihood of a caterpillar to leave its tie. We placed 1, 2, or 4 caterpillars in ties of a standard size and monitored the caterpillars twice daily to track their movement. In ties with more than one occupant, caterpillars showed a significantly greater propensity to leave their tie, and left sooner and at a faster rate than those in ties as single occupants. To understand the consequences of leaf tie abandonment, we observed caterpillars searching a tree for a site to build a shelter in the field. This is a risky behavior, as 17% of the caterpillars observed died while searching for a shelter site. Caterpillars that successfully built a shelter traveled 110 ± 20 cm and took 28 ± 7 min to find a suitable site to build a shelter. In conclusion, leaf-tying caterpillars must frequently abandon their leaf tie due to food limitation and interactions with other caterpillars, but this is a costly behavior