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Air pollution is one of the most environmentally harmful to the human health and the climate change. The present study is aimed to investigate the effectiveness and capability of novel composite adsorbents prepared from modification of activated carbons (ACs) in the removal of air pollutants. The effect of both triethoxysilane propylamine (TEPSA) and carbon nanotube (CNT) on the adsorption properties of AC (TEPSA/CNT/AC); in addition, silica gel prepared from TEPSA to form silica nanoparticles (SiNP) along with CNT and AC (SiNP/CNT/AC), was studied. Ammonia gas (NH3) was used in this study as a typical emerging gas air pollutant. The physicochemical characteristics of the prepared ACs samples were analyzed using BET surface area, SEM, EDX, TEM and FTIR. Their results proved considerable changes in the porosity and surface functional groups after modifying AC surface with TEPSA or SiNP and CNT instantly. The adsorption findings showed that the NH3 removal efficiency using the prepared AC samples reached almost 97, 86 and 75% during 90 min at 25 °C for each sample of SiNP/CNT/AC, TESPA/CNT/AC and AC, respectively. Adsorption of NH3 relied mainly on the presence of silica particles and mesopore distributions in CNT rather than large total surface area in AC alone. Thus, the combination of SiNP as silanol and siloxane groups with CNT on AC surface raised significantly the adsorption capacity of NH3 from 194 to 300 mg/g. Conclusively, the SiNP/CNT/AC sample exhibited the best performance among all prepared samples used for the adsorption of NH3 gas from the indoor air. Also, Langmuir and Freundlich models were applied, and the results revealed that Freundlich model fits well the equilibrium adsorption data. [ABSTRACT FROM AUTHOR]

Seismic structural fuses such as buckling restrained braces (BRBs) are highly nonlinear members that need a detailed finite element model (FEM) to represent their actual behavior. On the other hand, making detailed model for the whole building from solid or shell elements to be consistent with the model of BRBs would require expensive computational time and large storage space especially when performing nonlinear time history analysis (NTHA). Therefore, a mixed FEM is developed in this research so that the solid elements are used for the core plate and the restraining system only. The non-yielding segments of the BRBs and the conjoined girders and columns are simulated using beam elements with nonlinear material properties while the effect of large deformations is taken during analysis and this was able to represent plastic hinge formation, plastic rotations and residual displacements in such members. A beam-solid transfer mechanism is developed to properly transfer forces between the non-yielding segments of BRB and the inner solid plate. The core plate is connected to the surrounding restraining system with contact elements to simulate the normal and frictional forces generated upon contact based on the penalty algorithm. This model was validated using the data and the results of an experimental work mentioned in the literature where very good agreement was achieved. Thereafter, a rehabilitation study for the SAC 9-storey building was performed. The results showed how the BRBs work as structural fuses during earthquakes and confirmed the ability of the model to represent inelastic behavior of multi-story BRBFs. [ABSTRACT FROM AUTHOR]