This study aims to carry out a high-temperature exposure assessment for graphene oxide (GO) reinforced cement in terms of weight loss, flexural strength, and compressive strength. Different additive amounts of GO in cement are experimentally studied to unfold its effect on enhancing the mechanical performance of prepared GO reinforced cement. Temperatures are chosen as room temperature, 200, 400, 600, and 800°C, corresponding to different reaction status of cement. It is found that as the temperature increases, the water evaporates from the GO reinforced cement. Evaporated quantity of water relies on the reaction status, and the relation between weight loss and temperature is provided. Benefiting from the bonding effects of GO, hydrated calcium silicate hydrate (C–S–H) is chemically produced and, thus, a reticular bridging system, which is greatly helpful to enhance the flexural strength, is formed. Unlike flexural strength, adding GO into cement statistically has little effect on the compressive strength, except when the temperature rises up to 800°C due to the occurrence of decarburization from dehydration.

Acoustic horns can enhance the overall efficiency of loudspeakers to emanate highly directional acoustic waves. In this work, a theoretical model is developed to predict difference frequency acoustic fields generated by a parametric array loudspeaker (PAL) with a flared horn. Based on this model, analytical solutions are obtained for exponentially horned PALs. A numerical analysis on the performance of horned PALs subject to various horn parameters (i.e., horn length and flare constant) is implemented. To compare with nonhorned parametric acoustic array (PAA) devices, it is able to generate highly directional acoustic wave beams for a wide range of difference frequencies, in which the generated sound pressure levels at low frequencies can be significantly enhanced. In addition, the equivalent radius of a nonhorned emitter that matches the directivity achieved by a horned one is also quantitatively investigated. The present research will provide useful guidelines for the design and optimization of horned parametric array equipment.

Interfacial performance is quite significant for maintaining the structural performance of steel–concrete composite structures. Quantitative assessment on the interfacial effect is critical. For this reason, theoretical investigation on the interfacial interaction of steel–concrete composites was performed, with the symmetry of the model considered. Influence of interfacial slip on the mechanical properties of the composites was considered. Analytical solutions of the interfacial slip and strain were provided. The accuracy of the predictions from the improved analytical model was validated by comparing them against the results from experimental and numerical studies. The influence of design parameters of the composite members on the interfacial effect was discussed. The proposed analytical model was also employed to assess the effect of the bond developing at the interface between concrete and steel on the deformation exhibited by simple composite structural forms (e.g., beams). Through the analysis, the priority design parameters of the composite structures are determined for controlling the level of interfacial slip in order to achieve optimum bearing capacity. Different to commonly used energy methods, numerical methods and finite element methods, the study provides a simple and straightforward analytical solution for describing the interfacial interaction of composite structures for the first time, which can act as scientific instruction for the interfacial slip control of composite materials and structures.