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We assessed the usefulness of phase-change material (PCM)-based thermal plates fabricated from wood-plastic composites (WPCs) in mitigating the urban heat island effect. The thermal performance of plates containing PCMs with two different melting temperatures and with two different albedo levels was evaluated. The results showed that the PCM with a melting temperature of 44 °C maintained lower surface and inner temperatures than the PCM with a melting temperature of 25 °C. Moreover, a higher surface albedo resulted in a lower surface temperature. However, the thermal performance of PCMs with different melting temperatures but the same surface albedo did not differ. Using PCM-based materials in roof finishing materials can reduce surface temperatures and improve thermal comfort. [ABSTRACT FROM AUTHOR]

This study was undertaken to investigate the effect of loading rhBMP-2 onto biphasic calcium phosphate (BCP) and calcium pyrophosphate (CPP) on bone regeneration, and to examine the efficacies of BCP and CPP as rhBMP-2 carriers. Specimens were divided into the BCP, CPP, BCP/BMP, and CPP/BMP groups; BCP and CPP were in granules and not coated with rhBMP-2. BCP/BMP and CPP/BMP were prepared as discs, which were treated with rhBMP-2 and collagen. Physical and biological features were investigated using in-vitro and in-vivo tests. New bone area percentages (%) in the BCP/BMP and CPP/BMP groups were significantly greater than in the BCP and CPP groups. At weeks 4 and 8 post-implantation, CPP/BMP showed the most new bone growth. Within the limitations of this study, treatment of BCP and CPP with rhBMP-2 significantly enhanced bone regeneration. CPP was found to be a suitable carrier for rhBMP-2. [ABSTRACT FROM AUTHOR]

The objective of this research was to develop environment-friendly Hwangtoh binder for application of Hwangtoh for interior wall finishing materials in the housing. To mix with Hwangtoh powder, water soluble melamine-polyurethane copolymer (MPU) resin with ethylene-vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), CaCO3, and inorganic fillers were designed. Far infrared ray irradiation, total VOC (TVOC) emission behavior, surface bonding strength, and surface crack behavior were studied by comparing to epoxy/Hwangtoh blend as control. For TVOC emission behavior, the 20 L small chamber method was used and the results satisfied the requirements of the excellent grade of TVOC of Korea Air Clean Association. To utilize the advantage of Hwangtoh, such as high absorbency, self-purification, deodorizing, sanitizing properties, and radiation of far infrared rays in the field of modern housing, this study was the foundation to develop environment-friendly binders for Hwangtoh. [ABSTRACT FROM AUTHOR]

Polyvinyl acetate (PVAc) was added as a replacement for melamine-formaldehyde (MF) resin in the formaldehyde-based resin system to reduce formaldehyde and volatile organic compound (VOC) emissions from the adhesives used between plywoods and fancy veneers. A variety of techniques, including 20-l chamber, field and laboratory emission cell (FLEC), VOC analyzer and standard formaldehyde emission test (desiccator method), were used to determine the formaldehyde and VOC emissions from engineered flooring bonded with five different MF resin and PVAc blends at MF/PVAc ratios of 100:0, 70:30, 50:50, 30:70 and 0:100. Although urea-formaldehyde (UF) resin had the highest formaldehyde emission, the emission as determined by desiccator method was reduced by exchanging with MF resin. Furthermore, the formaldehyde emission level was decreased with increasing addition of PVAc as the replacement for MF resin. UF resin in the case of beech was over 5.0 mg/l, which exceeded E2 (1.5–5.0 mg/l) grade. However, MF30:PVAc70 was ≤E1 (below 1.5 mg/l) grade. Because formaldehyde emission is caused by formaldehyde-based resin, the engineered floorings bonded with PVAc only had emissions of just 0.25 mg/l. The results of formaldehyde emission by the 20-l small-chamber and FLEC methods showed a similar tendency with those from the desiccator method. After the replacement of UF resin by MF resin, PVAc addition further reduced formaldehyde emission. With increasing installation time, formaldehyde emission factors (EFs) were decreased. Furthermore, the results of the desiccator method correlated with those of the 20-l chamber and FLEC methods. VOC emission results by 20-l small-chamber and FLEC methods were similar to the formaldehyde and aldehyde emission results. VOCs were calculated between C6 and C16 as total VOC (TVOC). The TVOC EF results by 20-l small-chamber and FLEC methods were comparable with that of formaldehyde emission by FLEC. Although the major emitted harmful gas from wood-based composites was formaldehyde, it was followed by VOC emission. Although it was hard to compare directly the 20-l chamber and FLEC results because the data were based on the sum of only four VOC compounds, the VOC analyzer can be applied as a pre-test method for TVOC emission test. The TVOC emission results were also similar to the FLEC results. Due to its good correlation with the TVOC emission levels obtained from the standard desiccator, FLEC and 20-l chamber methods, the VOC analyzer can be successfully applied to the measurement of TVOC emissions from adhesives used in building materials. Practical Implications This paper presents TVOC and formaldehyde emission behaviors from the engineered floorings that used in Korean housing recently. To reduce emissions, MF/PVAc hybrid resins were used as bonding material. Normally, TVOC and formaldehyde emissions in indoor conditions are caused by interior materials. The results explained ‘materials control’ of interior materials are the first way to improve indoor air quality. There is a need to study about environmental-friendly materials for solving indoor air quality problem. [ABSTRACT FROM AUTHOR]