ABSTRACT
This article investigates the dispersion of airborne pollutants emitted from different locations near a high-rise building. A Computational Fluid Dynamics (CFD) model for simulating the wind flow field and the pollutant dispersion was developed and validated by wind tunnel data. Then the spreading of the pollutant emitted from different locations to a rectangular-shaped high-rise residential (HRR) building was numerically studied. The pollutant source location was set in a wide range of the position angle and distance between the source and the building. It was found that the pollutant concentration on the building decreases with an increase in the emission distance whereas the effect of the position angle is more complicated. Interestingly, there is a critical range of the position angle from which the emitted pollutants will not spread to the building in a significant way. The effect of the source location was linked to the wind flow field around the building, particularly with several major flows. The vertical distributions of the pollutant concentration on different faces were also investigated, and it was found that these are more affected by the vertical flow near each face. Finally, a mathematical model was developed to evaluate the pollutant concentration as a function of the emission distance and position angle. These findings are helpful to the understanding of the dispersion of airborne pollutants around high-rise buildings and the related hazard management in urban design.
ABSTRACT
OBJECTIVE: The aim of this study was to provide more reliable and robust norms for the Motion Sickness Susceptibility Questionnaire (MSSQ-Short). BACKGROUND: The previous norms for the MSSQ-Short involved a small sample overrepresenting younger female participants, which may provide misleading estimates of susceptibility in the general population. METHOD: We measured MSSQ-Short scores in a sample of 1,711 members of the general public in New Zealand and Australia. The sample is 6.6 times larger than the original norm sample, and age and gender closely match the general population. RESULTS: Compared with the current study, the original norms underrepresent those of high susceptibility by a factor of 3.6, or 0.52 standard deviations. The analysis detected higher levels of susceptibility in females and significantly lower susceptibility in those ages 65 years and older. CONCLUSION: This study provides the largest sample of MSSQ-Short scores with more representative demographic characteristics of age and gender. Despite the potential for a self-selection bias toward high levels of susceptibility, we argue that the current norms provide more reliable and robust norms than the original sample. APPLICATION: These updated norms provide the tools for researchers and designers to evaluate the likely effect of various motion environments on the general population. Robust norm data can inform research, including general motion sickness research and environmental design.
