The study shows that unique emission patterns may exist for different types of building materials. These patterns, or signatures, can be established by using PTR-MS, an online monitoring device. The sum of selected major individual VOC odor indices determined by PTR-MS correlates well with the acceptability of air quality assessed by human subjects, and hence provides a feasible approach to assessing perceived indoor air quality. This online assessment will open a new gate in understanding the role of VOC emissions from building materials on perceived air quality, forming a good foundation to develop real-time or near real-time methods for standard material emission testing and labeling, quality control of emissions from materials, and assessing the acceptability of air quality in buildings.

No abstract

No abstract

We theoretically study the propagation of hybrid electromagnetic-spin waves in a multiple-band-stop microwave waveguide, which is constructed as an antiferromagnetic (AFM1)/dielectric/antiferromagnetic (AFM2) sandwiched structure. Band stops, which are characterized by multiple attenuation peaks, have been found in the system. The frequencies of multiple band stops and the intensities of attenuation peaks can be manipulated by external magnetic field. However, by tuning the thickness of the dielectric layer or the thickness of AFM layers, the frequencies of the band stop are almost invariable, while the intensities of the attenuation peaks change significantly. This feature originates from the coupling between the microwave and spin wave associated with the collective excitations of spin motions. Our investigation may potentially be applied to the design of high-frequency microwave band-stop filters.