ABSTRACT
Recently, the importance of mechanical facilities in charge of the safety and comfort of occupants in buildings has once again been highlighted in accordance with global social issues such as the spread of COVID-19. In response, various ventilation systems are being developed to improve indoor air quality, and efforts are being made to satisfy the indoor comfort of the occupants. Such advanced facilities allow occupants to secure indoor air quality, while frequent ventilation systems can affect the cooling and heating load in the building, and there is also a problem that it can occupy a relatively large amount of space in the building. This study proposes an integrated, outdoor fan-ventilated cooling device and analyzes its performance and economic efficiency. The EnergyPlus simulation program was used to model two types of systems for comparison: an existing (base) model with a condenser located in the outdoor unit, and a developed model with the condenser integrated within the cooling system. The state of the air passing through the condenser was analyzed prior to comparing the efficiency of the integrated, outdoor fan-ventilated cooling device, followed by an in-depth analysis of the performance and economic efficiency based on total energy consumption. In Case 1, the air passing through the cooling system was approximately 5 °C lower than the base model and showed 11% peak load reduction in comparison to the maximum energy consumption. Additionally, a comparison between regions with different outdoor air temperatures showed an average cost reduction of 16% in Daejeon and Busan City.
ABSTRACT
OBJECTIVES: Bacillus Calmette-Guérin (BCG) vaccination has proven to be efficient in immunologically naïve infants; however, it has not been investigated that maternal natural exposure to Mycobacterium and/or BCG vaccine could influence the characteristics of immune responses to BCG in newborns. In this study, we analyzed whether the maternal immune status to M tuberculosis (M tb) can affect neonatal immunity to BCG using a mouse model. METHODS: Neonates were obtained from mice that were previously exposed to live BCG, to live M avium, or to heat-killed M tb H37Rv, and from naïve control mothers. One week after birth, the neonates were divided into two subgroups: one group immunized with live BCG via the subcutaneous route and the other group of neonates sham-treated. Interferon-gamma (IFNγ) secretion in response to in vitro stimulation with heat-killed BCG or purified protein derivative (PPD) was examined. Protection against M tb infection was evaluated by challenging mice nasally with live M tb H37Rv followed by counting colonies from spleen and lung homogenates. RESULTS: BCG-immunized neonates showed increased IFNγ secretion in response to heat-killed BCG or PPD. All mice in BCG-immunized neonates subgroups showed reduced bacterial burden (colony forming unit) in the lungs when compared with control naive neonate mice. However, no statistically significant difference was observed when comparing BCG-immunized mice born from mothers previously exposed to M avium or immunized with either heat-killed H37Rv or live BCG and mice born from naïve mothers. CONCLUSION: The maternal immune status to M tb does not appear to impact on the immunogenicity of BCG vaccine in their progeny in our experimental conditions.
