A Comparative Field Study of Indoor Environment Quality and Work Productivity between Job Types in a Research Institute in Korea.

Indoor environment quality (IEQ) evaluation can help improve building satisfaction and productivity of residents. However, for more efficient analysis, it is necessary to gain a large amount of data on the differences between specific groups, such as building and resident work types. In this study, we conducted an IEQ evaluation for administrators and researchers, which are occupational groups of a research institute. The evaluation was conducted using quantitative and qualitative methods to find the relationships between IEQ satisfaction and work productivity for each job type. Our results showed that light environment and office layout were correlated with the work productivity of administrators, and light environment, office layout, thermal comfort, and sound environment were correlated with the work productivity of researchers. In addition, there was a significant difference in layout and thermal comfort items between administrators and researchers. Therefore, this study revealed significant differences in the effect of IEQ evaluation on work productivity between different occupations in a research institute.

Impact of ventilation methods on indoor particle concentrations in a daycare center.

The objective of this study was to quantify the influence of ventilation methods on children's exposure to indoor particles in a daycare center located in an urban area. The ventilation methods applied to the center were monitored for 1 year. It appears that indoor PM10 and PM2.5 concentrations of the center were basically determined by outdoor conditions. The fluctuations in outdoor particle concentration also affected the ventilation behavior during class. The windows and doors of the classroom were frequently closed during both class hours and nights when the outdoor particle concentrations were at high levels. Statistically significant differences in the I/O ratios were found among the ventilation methods. The PM10 I/O ratio with the closed windows was significantly higher (p < 0.01) than that with the open windows, and when the mechanical fans were operated, the I/O ratio dramatically decreased (p < 0.01). The I/O ratio of PM2.5 showed a similar trend to that of PM10 except for the mechanical fan operation. The filters rated lower than MERV 11 appear to be insufficient to remove submicron particles from the mechanically supplied outdoor air when the PM2.5 concentrations are high, such as during the heating period.

Annual performance evaluation of thermoelectric generator-assisted building-integrated photovoltaic system with phase change material.

Owing to the economic recession due to the Coronavirus disease (COVID-19) pandemic, energy-efficient building retrofitting has been considered as an integrated solution to recover the economy and maintain global greenhouse gas reduction. As part of retrofitting existing building-integrated photovoltaic systems during building renovations, this study evaluated the energy generation potential of a thermoelectric generator-assisted building-integrated photovoltaic system with a phase change material. The combination of a thermoelectric generator and phase change material with photovoltaic systems results in solar cell temperature reduction and additional electricity output owing to the Seebeck effect, increasing the total generated energy from the system. Simulations of the proposed system were performed using MATLAB R2020a, based on transient energy balance equations. The appropriate melting temperature and thickness of the phase change material were derived to maximize the annual electricity generation of the proposed system from simulations of 12 design days in each month. The proposed system with the selected phase change material conditions exhibited a 1.09% annual increase in generation output and 0.91%, -1.32%, 2.25%, and 3.16% generation improvements from spring to winter, compared with the building-integrated photovoltaic system alone. Theoretically, the proposed system is expected to generate 4.47% more energy by minimizing the thermal resistance of the system and improving thermoelectric generator performance.

Numerical and Experimental Study on the Performance of Thermoelectric Radiant Panel for Space Heating.

The purpose of this study is to investigate the suitable operation and performance of a thermoelectric radiant panel (TERP) in the heating operation. First, the hypothesis was suggested that the heating operation of TERP can operate without a heat source at the cold side according to theoretical considerations. To prove this hypothesis, the thermal behavior of the TERP was investigated during the heating operation using a numerical simulation based on the finite difference method. The results indicated that it is possible to heat the radiant panel using a thermoelectric module without fan operation via the Joule effect. A mockup model of the TERP was constructed, and the numerical model and hypothesis were validated in experiment 1. Moreover, experiment 2 was performed to evaluate the necessity of fan operation in the heating operation of TERP regarding energy consumption. The results revealed that the TERP without fan operation showed the higher coefficient of performance (COP) in the heating season. After determining the suitable heating operation of the TERP, prediction models for the heating capacity and power consumption of the TERP were developed using the response surface methodology. Both models exhibited good R2 values of >0.94 and were validated within 10% error bounds in experimental cases. These prediction models are expected to be utilized in whole-building simulation programs for estimating the energy consumption of TERPs in the heating mode.

Toll-like receptor 9-mediated inhibition of apoptosis occurs through suppression of FoxO3a activity and induction of FLIP expression.

Synthetic oligodeoxynucleotides (ODN) with a CpG-motif are recognized by Toll-like receptor 9 (TLR9) and pleiotropic immune responses are elicited. Stimulation of macrophages with TLR9 agonist prevented apoptosis induced by serum deprivation through increased expression of FLICE-like inhibitory protein (FLIP). CpG ODN-mediated anti-apoptosis depended on the TLR9-Akt-FoxO3a signaling pathway. Inhibition of TLR9 by small interfering (si) RNA or an inhibitor suppressed CpG ODN-mediated anti-apoptosis. Analysis of signaling pathways revealed that the anti-apoptotic effect of CpG ODN required phosphorylation of FoxO3a and its translocation from the nucleus to the cytosol. Overexpression of FoxO3a increased apoptosis induced by serum deprivation and CpG ODN blocked these effects through FLIP expression. In contrast, siRNA knock-down of FoxO3a decreased apoptosis by serum deprivation. In addition, Akt activation was involved in CpG ODN-induced phosphorylation of FoxO3a, expression of FLIP, and anti-apoptosis. Taken together, these results demonstrate the involvement of Akt-FoxO3a in TLR9-mediated anti-apoptosis and indicate that FoxO3a is a distinct regulator for FLIP expression.