Cold‐formed steel‐framed gypsum partition walls (hereinafter referred to as partition walls) sustain the seismic damage induced by small story drifts. The impacts on the functional deterioration and monetary loss of buildings are enhanced in earthquake events where structural damages are limited. Although the boundaries of partition walls vary by location in a building structure, the existing studies assume a typical partition wall surrounded by a frame consisting of columns and girders. In particular, the vertical boundary members vary from a column, stud column, and wall panel. Our present work investigates the influence of the boundaries on seismic damage and fragility assessment of partition walls using an experimental dataset of cold‐formed steel‐framed gypsum partition walls with various boundaries obtained at an E‐Defense shake table on a four‐story steel frame. A damage mechanism model considering the deformation and rigid body motion of the partition walls and boundaries suitably explains the observed damage variations and underlying mechanisms. This study also presents the non‐negligible impact of boundaries on the fragility and expected repair time and cost model of the partition walls. The presented results are critical in providing references for the layout of partition walls, damage predictions, construction improvements, and repair strategy.

Past earthquakes highlighted the vulnerability of the suspended ceiling, especially in earthquake‐prone countries like Japan; the post‐earthquake reconnaissance showed that damage to ceiling systems led to immeasurable economic loss and disturbance of the timely rescue of casualty. The existing studies have mostly focused on the seismic performance of regular square and leveled ceilings, whereas the inevitable requirements to accommodate air ducts, nonstructural piping, and electrical equipment resulted in a two‐elevation ceiling system. This paper reports a series of full‐scale shake table tests on a typical two‐elevation ceiling system, which includes electrical equipment, piping system, and commonly used suspended ceiling structure. Experimental observations showed that the two‐elevation ceiling system performed well under earthquake excitation. No fallen panels or overall system collapse occurred during shaking. This paper discusses the effects of a temporary‐positioning‐bracing bar (TPBB) between two ceiling elevations and peripheral constraints by surrounding wall on the acceleration and displacement response and torsional behavior in the ceiling system. Then, a simplified analytical model was established and verified with the experimental response of different ceiling configurations. The test results indicated that a sufficiently strong TPBB is essential to reduce the relative displacement between two ceiling elevations, and it ensures the integrity of two ceiling elevations in the ceiling system. In conclusion, the TPBB shall remain in the ceiling system after the construction stage.

Many recent studies have suggested that activation of the aryl hydrocarbon receptor (AhR) reduces immune responses, thus suppressing allergies and autoimmune diseases. In our continuing study on natural AhR agonists in foods, we examined the influence of 37 health food materials on the AhR using a reporter gene assay, and found that aqueous ethanol extracts of cassia seed and rosemary had particularly high AhR activity. To characterize the AhR-activating substances in these samples, the chemical constituents of the respective extracts were identified. From an active ethyl acetate fraction of the cassia seed extract, eight aromatic compounds were isolated. Among these compounds, aurantio-obtusin, an anthraquinone, elicited marked AhR activation. Chromatographic separation of an active ethyl acetate fraction of the rosemary extract gave nine compounds. Among these compounds, cirsimaritin induced AhR activity at 10-10 2 μM, and nepitrin and homoplantagenin, which are flavone glucosides, showed marked AhR activation at 10-10 3 μM.

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This paper presents seismic damage to continuous ceiling systems and the impact of damage on functionality in the hospital specimen tested at the E-Defense shaking table. The specimen had four ceiling systems with different peripheral constraint conditions, coverage areas, suspended lengths, and ceiling panel materials. The test results demonstrate that the continuous ceiling system is less susceptible to collapse than the lay-in ceiling system. However, medical facilities require maintaining functionality after earthquakes, and the consequence of damage as functional deterioration needs discussion. The twoelevation ceiling system across two rooms with different ceiling heights sustains severe damage at the rise-up part and the partition wall separating the rooms.The damage becomes severe when the ceilings at different heights vibrate at separate frequencies. The results highlight the enhancement of the lateral stiffness of the suspended ceiling at the rise-up part, such as by adding bracing bars. In the case of long-duration shakings assumed for far mega-earthquakes, damage accumulates with repeated loadings, and the functional loss by the damage becomes intense. This observation indicates that peak-related parameters (peak floor acceleration or peak floor velocity) do not comprehensively reflect the degree of damage in ceiling systems. The proposed functionality loss matrix highlights that the damage to the ceiling harms the aseptic environment for key medical rooms, especially for the cleanroom with extremely strict requirements on the air environment.