To monitor the concentration of particulate matter (PM) from cooking fumes, an in-line measurement method was proposed based on the Lorenz–Mie scattering theory, and a measurement system was developed based on the side-scattering imaging technique with a laser beam for illumination. Polystyrene particles in water suspensions with a known particle size and concentration were utilized for validation. The experimentally obtained gray level of the image of the particle cloud along the laser beam agrees well with that predicted by theoretical model in the same configuration. The artificial fish swarm algorithm was adopted for inversion, and the results of particle size measurements show a standard deviation lower than 5% of the mean measured value at concentrations of 0.5–50 mg · m−3. Using the retrieved particle size distribution, the PM concentrations can be measured with the calculated scattering coefficient k 2 and the measurement system dependent coefficients I 0 k 1. The calibration experiments with polystyrene particle suspensions show a very good linear relationship of the image gray value on the particle concentration. This method makes it possible to monitor the PM concentrations using a non-contact and non-suction approach.

In order to understand deeply the dynamic behavior of a Temporary Demountable Structure (TDS), a 2-D analytical model of the Wedge-Pin Joint (WPJ) is established. This model takes into account of the semi-rigidness of the vertical contact and the sliding between beam and column based on the frictional shear-slip mechanism. The analytical WPJ model is validated by comparing with the dynamic responses of the TDS modeled with that obtained from the finite element model under harmonic load. Furthermore, a thorough dynamic analysis of the TDS subjected to a bipedal walking force is conducted. Results show that the hysteretic effect of the WPJs can be induced in the system. It is strongly affected by the amplitude of excitation, and a larger excitation does not mean a stronger hysteresis. This can be interpreted by that large horizontal contact force for joints resulted from strong excitation in horizontal direction yields high friction, which enhances the clamping effects in vertical and then weakens the hysteretic effect of WPJs. In addition, the vertical slip for joint is limited to a small value due to a relative small acceleration, this small vertical slip leads to a small of hysteretic loop. Finally, it is also found that the semi-rigidness of WPJs can apparently increase the deformation and acceleration of the system in both horizontal and vertical directions. This research provides for the first time an analytical model of WPJs of TDS, which will be beneficial to the future research of human-TDS interaction.