Narrow Results

This paper presents a study on optimization of design parameters and positions of single tuned mass damper (STMD) and multiple tuned mass dampers (MTMDs), used as vibration control systems in buildings under seismic excitations aiming to reduce their story drift. As case studies, three buildings are subjected to three real earthquakes and one non-stationary artificial earthquake, and their responses are analyzed. For each building, different control scenarios are proposed and to run the optimizations, the whale optimization algorithm (WOA) was used. The results showed that for Building 1, the Scenario 1-Optimized, with a STMD at the top floor, was the best alternative. In Building 2, the Scenario 1-Optimized, with also a STMD at the top floor, proved to be the best solution. Finally, for Building 3, the Scenario 4-Modified, with 3 TMDs arranged in the building elevation plane was the only one that had effective control of structural response, therefore, it is the best control scenario.

The electronic band structure, density of states, optical absorption, phonon spectrum, stability, and thermodynamic properties of 1T’-phase RuOsSe₂ hybrid monolayer were systematically studied using ab initio calculations based on Density Functional Theory (DFT) and Density Functional Perturbation Theory (DFPT) within the generalized gradient approximation (GGA) and the HSE06 functional of hybrid correlation–exchange. Indirect bandgaps $E_g=0.68$eV and $E_g=1.23$eV were obtained within the calculation level GGA-PBE and HSE06. The investigation of optical absorption shows that the RuOsSe₂ monolayer exhibits a significant absorption in the ultraviolet and visible regions of the electromagnetic spectrum. Thermodynamic potentials and specific heat at constant volume were calculated, of which dependence on the temperature is discussed. We predict a new RuOsSe₂ monolayer from the 1T’ phase that could potentially be synthesized for future electronic devices and bring potential technological applications.

Liquid storage tanks are widely used in the industrial and the agricultural production, the earthquake damage of the liquid storage tanks will not only lead to economic losses, but also may cause environmental pollution, fire and explosion. Considering the fluid–structure interaction, the liquid sloshing and the material nonlinearity, the three-dimensional numerical calculation models of nondamping and tuned mass damper (TMD) liquid storage tanks are established, respectively. The earthquake waves with different characteristics are selected to investigate the dynamic responses of the liquid storage tank, the control effects of the TMD on the seismic responses of the liquid storage tank are analyzed, and the influence law of the change of the spring stiffness on the damping effect is discussed. The results show that the TMD has a significant damping effect on the liquid storage tank, and the element damping has significant influence on the dynamic responses in the subsequent stage of the earthquake action. Under the action of Darfield–New Zealand wave, the damping ratio corresponding to the acceleration of the tank wall is 69.6%. When the element damping is not considered, the small change of the spring stiffness has significant influence on the damping effect, but after the element damping being considered, the influence of the spring stiffness change on the damping effect is small. The TMD provides a high performance system to the damping control of the liquid storage tank under the action of earthquakes with different intensity.

New supramolecular hydrogen bonded mesogens are designed with the non-covalent interactions between the two polar groups. Interesting observations made in the synthesis of new hydrogen bonded mesogen between the mesogenic group p-n-alkyl benzoic acid with n representing the alkyl carbon number from pentyl to decyl of benzoic acid group and non-mesogen ortho-toluamide containing nitro group. The thermodynamic properties of the observed textures are studied by polarizing optical microscope and compared with the corresponding differential scanning calorimetry. The results of hydrogen-bonded mesogen are studied in comparison with the free p-n-alkyl benzoic acids. The intermolecular hydrogen bonding between the two polar groups convinced by FT-IR favours the formation of hydrogen-bonded mesogen with crystal G phase different from their constituents.