ABSTRACT
Recently, clothing development 3D printing and the evaluation of its physical characteristics have been explored. However, few studies have tackled thermal comfort, which is a major contributor to the wearers' comfort. Therefore, this study was designed to suggest effective materials and hole sizes for clothing obtained by 3D printing to maintain a comfortable clothing environment. In particular, two main variables, namely five different materials and three-hole sizes, were analyzed. All samples were placed on a hot plate (36 °C), and their surface temperature and humidity were measured for 10 min. The samples with only thermoplastic polyurethane (TPU) achieved the largest temperature change of 3.2~4.8 °C, whereas those with ethylene-vinyl acetate (EVA) foam exhibited the lowest temperature change of -0.1~2.0 °C. Similarly, the samples with only TPU showed the greatest humidity change of -0.7~-5.5%RH. Moreover, the hole size had a larger effect on humidity change than material type. The samples with large holes achieved the largest humidity change of -4.4%RH, whereas the samples without holes had the smallest humidity change of -1.5%RH after 10 min (p < 0.001). Based on these results, various combinations of materials and hole sizes should be considered to fit the purpose of 3D printing clothing.
ABSTRACT
Biofouling is a stubborn problem in cooling systems where using raw water from lakes, rivers, and sea. The effect of ultrasound and its sequential application with sodium hypochlorite (chlorination) upon marine bivalve Mytilus edulis (blue mussel), a massive fouling organism, has been studied and discussed here. The results obtained from the work carried out have shown that 42 kHz ultrasound is better than 28 kHz in accordance with veliger larvae mortality. The 42 kHz ultrasound has enhanced the mortality rate of veliger larvae than only free-residual chlorination up to 99%. On the other side, the 14-mm size mussel was less resistance than 25-mm size mussel to 42 kHz ultrasonication, among the studied two sizes (14 and 25 mm) of the blue mussel. Lethal time (100%) have decreased by 1-12% used for the sequential action of 42 kHz ultrasonic followed by free-residual chlorination compare with only free-residual chlorination treatment. The obtained results are put forward that the application of ultra-sonication before chlorination can reduce the mussel extinct time up to 12%. Obviously, this result will provide a possible use of ultra-sonication with famous chlorination antifouling treatment and eventually can decrease the chlorine exposure time and dose. It could discharge low chlorine by-products that may provide an environment friendly way.
