Samuelsenkirkland8173

Susceptibility of the AA5083 FSW joint to pitting corrosion was attributed to the difference of relative potential between the intermetallic phase and Al matrix.This work was aimed to improve the shear strength of disintegrated carbonaceous mudstone (DCM) with nanotalc (NT). A series of direct shear tests were carried out on the NT-modified DCM specimens to determine their shear strengths at various NT concentrations. Subsequently, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to reveal the underlying mechanism which the results showed that shear strength was first increased and then decreased with increasing certain NT concentration. Moreover, the increase in NT concentration also resulted in rise in cohesion and reduction in angle of internal friction. The optimum NT concentration for shear strength improvement of DCM is 4%. This improvement of shear strength is achieved because NT can fill the pores in DCM and its products can bind with particles. Decitabine This results in formation of large aggregates owing to the small size, strong adsorption capacity and cation-exchange capacity.Efficacy of added nano-CaCO₃ (NC) on engineering performances, including fluidity, initial setting time, bleeding rate and yield stress of cement grouts was investigated in this study. Results showed that the fluidity and bleeding rate for NC-cement (NCC) composite grout first decreased with increased NC content (i.e., ratio of NC mass to cement mass) and then slightly recovered as the NC content exceeded 2%. The initial setting time was always reduced while the yield stress increased with increased NC content. The microstructure of NCC was analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the NC can promote the cement hydration, but an excess amount of NC will inhibit the cement hydration and affect the engineering performances of cement grouts. The optimum NC content for modification of cement grouts was thus 2%.Modifying epoxy asphalt with nanomaterials is an effective method to enhance the performance of epoxy asphalt binder. The carbon nanotubes were modified and carbon nanotubes/epoxy asphalt (CNTs-EA) was fabricated by mechanical stirring. The performanceof CNTs-EA pavement binder (CNTs-EAPB) was analyzed by immersion marshall's, freeze-thaw splitting and dynamic stability tests. Experimental results showed that the dynamic stability and freeze-thaw splitting intensity of matrix asphalt binder (MAB) were improved by 118.6% and 85%, respectively. While the dynamic stability of CNTs-EAPB remained 90.8% under soaking water which was more than 77.44% of matrix asphalt and reached 5801 times per mm. This enhancement is mainly attributed to excellent characteristics of CNTs as well as the effective synergistic effect between CNTs and epoxy resin.In this work, coral-like CuO dendrites were successfully synthesized by a solvothermal method in the mixed solvent of distilled water and ethanol with assistance of dodecyl trimethyl ammonium bromide (DTAB). The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analysis techniques, to investigate their structure and morphology. The coral-like CuO dendrites were about 1 μm in length, with many dendrites pointing to a common center. The influence of experimental conditions on morphology, such as volume ratio of water to ethanol, surfactant DTAB and molar ratio of Na₂CO₃ and Cu(CH₃COO)₂, was also discussed. Time-dependent experiment was carried out to explore the formation mechanism while a "particle-sheet-dendrite (PSD)" mechanism was proposed to explain the growth process. The as-prepared CuO dendrites were used to degrade methylene blue (MB) under visible light irradiation in the presence of H₂O₂, where over 98% of methylene blue (MB) was degraded in 1 h. Results from the study demonstrated that the as-prepared coral-like CuO dendrites exhibited enhanced photocatalytic performance and excellent stability and reusability.The adsorption capability of eosin Y as a model anionic dye on natural halloysite nanotubes (HNTs) and sulfuric acid-treated HNTs as a function of acid treatment time (1 h, 3 h, and 5 h) was examined. Scanning electron microscopy revealed that natural HNTs had a very uniform surface, whereas acid-treated HNTs had a rough surface with structural defects, which increased with acid treatment time. The total specific pore volume and total surface area of the acid-treated HNTs increased due to formation of nanopores in the HNTs via dissolution of the inner AlO6 octahedral layer. With acid treatment, the surface ξ-potentials were positively shifted from -42.9 mV (for the natural HNTs) to -1.9, -3.0, and +1.2 mV after 1, 3, and 5 h, respectively. The adsorption amount (qe) of eosin Y on natural HNTs and the three acid-treated HNTs was 2.3, 125.5, 118.9, and 118.9 mg g-1, respectively, implying that the adsorption capacity of acid-treated HNTs is ~50 times higher than that of natural HNTs. In this study, we clearly demonstrated that acid-treated HNTs can be used as highly efficient nanomaterials for removal of dyes from wastewater containing anionic dyes.To obtain a high S-loading cathode for a Li-S battery, we propose a free-standing carbon nanotube (CNT)-based S cathode, which consists of two layers a pure S deposition layer with a thickness of 20 μm, and a S-containing CNT film (S-CNT). Based on scanning electron microscopic (SEM) studies, it was observed that the S layer completely vanished when the cell with the S/S-CNT cathode was discharged to 2.1 V after cell assembly, indicating that the thick sulfur film dissolved in the form of polysulfide intermediates during discharge. The proposed S/S-CNT cathode delivered double the areal capacity with good capacity retention of 83% after 100 cycles, compared with that of the control cathode (S-CNT). Thus, we believe that our new cathode design will be useful in developing stable, high-energy Li-S batteries.