Effective cooling strategies are critical for cultivating high-quality ornamental plants during the summer. The fan-and-pad cooling system reduces greenhouse temperatures by drawing air through wet pads, which humidify and cool the air, aided by fans on the opposite side. However, the paper-based pads (corrugated cellulose) used in this system have limited durability and degrade with prolonged use. Nanocomposite hydrogels, with their polymer-based structure, can absorb and retain moisture through swelling, presenting a promising alternative. This study examines the application of nanocomposite hydrogels, focusing on their hygroscopic properties and cooling efficiency under various temperatures and wind speeds. When treated with lithium chloride solutions at 25%, 50%, 75%, and 100% saturation, higher LiCl concentrations reduced weight but increased swelling capacity. Optimal cooling effects were achieved with wind speeds of 1.0 m/s at 25°C and 1.5 m/s at 35°C, with greater efficiency observed at lower wind speeds. These findings suggest that integrating nanocomposite hydrogels into cooling pads could enhance durability and reduce maintenance compared with conventional paper pads.

Composite pavements are constructed by placing a high functional asphalt surface layer on a high performance concrete rigid base layer and provide a more durable, high functional surface to road users. Service life of composite pavements is dependent on the bonding performance of the lower rigid base and the flexible surface layer. Accordingly, it is necessary to place an impermeability layer between the functional surface layer and the rigid base to enhance bonding performance and to prevent moisture penetration into the rigid base and deterioration of pavement. In order to use optimal composite pavement sections, two types were applied to impermeability layer: highly impermeable water-tight SMA and mastic asphalt currently in use. APT (Accelerated Pavement Testing) and experimental construction were carried out to evaluate bond strengths between the rigid base and the impermeability layer depending on the type of impermeability layers. Composite pavement sections for the APT had a 22 cm concrete rigid base layer and a 5cm functional surface, as well as either 5cm of SMA impermeability layer and 5cm of mastic layer. After applying around 8,574,000 ESALs, pull-off test was conducted, which showed that the mastic section outperformed the SMA section. In the experimental construction, three types of rigid base layers, JCP (Jointed Concrete Pavement), CRCP (Continuously Reinforced Concrete Pavement), and RCCP (Roller Compacted Concrete Pavement), were used for composite pavement sections, and as in the APT, two types of impermeability layers, SMA and mastic, were used per rigid base layer of new and deteriorated concrete pavement. Therefore, seven composite pavement sections in total were constructed. We measured the bond strength over one year or so following the construction of these composite pavement sections and found that regardless of the type of rigid base layer and whether it was new or not, those sections with a mastic impermeability layer had high bond strengths.

The purpose of this study is to understand the relationship between female college students’ stress level and premenstrual syndrome so that it can provide baseline data on how to cope with the syndrome. The study subjects are 250 female college students in Gyungbook area. This study chose 199 appropriate subjects and collected data. As per general menstrual phases, this study investigated the age when one had her first period, regularity and duration of period, and amount of bleeding. It used a measurement tool to measure stress level and premenstrual syndrome. Most of the subjects experienced their first period before the age of 13. The menstrual period was irregular with the duration of less than 7 days. 123 subjects had normal amount of bleeding. 121 subjects were experiencing high level of stress over 2.4. The correlation between the level of stress and premenstrual syndrome factors showed significant static correlation for each factor. Especially, the correlation between digestive system and response of autonomic nervous system was .996 and negative emotion and behavioral change was .635, and negative emotion and pain was .614 which were relatively high. The regression analysis of factors of premenstrual syndrome depending on the subjects’ stress level indicated that response of autonomic nervous system had the biggest effect in the low stress group while behavioral change, negative emotion, pain, decreased concentration, water congestion, response of autonomic nervous system, and skin change had the biggest effect in the high stress group with statistical significance. Based on the result, it can be said that higher premenstrual stress is closely related to the premenstrual syndrome one experiences for some female college students.