Abstract: Liquefaction-induced sand boils were observed in the Sinhua District, Tainan during the 1946 Xinhua Earthquake. Liquefaction phenomena were observed in the same area following the 2010 Jiasian Earthquake. More re-liquefaction sand boils occurred after the 2016 Meinong Earthquake. The locations of sand boil craters induced by the Taoyuan and Meinong earthquakes were overlapped. After the Jiasian Earthquake in 2010, borehole drilling and cone penetration tests were conducted in the region. Similar investigations were repeated following the Meinong Earthquake in 2016. This study examines the soil layer characteristics and evaluates the liquefaction potential based on the CPT sounding at different time periods.

Abstract: In this study, electrochemical activation of persulfate using iron electrodes is applied to treat trichloroethylene (TCE) in groundwater. The effects of various factors, including current density, persulfate concentration, and anion type and anion concentration, on TCE oxidation are evaluated. In addition, a persulfate tablet, a long-lasting persulfate release material, is combined with the electrochemical activation system for in situ groundwater remediation. At persulfate concentrations of 4.2  10-3 to 4.2  10-2 M, TCE (4  10-4 M) removal reaches 98.4 to 100% at current densities of 0 to 12.5 mA/cm2 during 60 min of reaction. Additionally, cis-1,2-dichloroethylene is detected during the experiments, which indicates that the reductive dechlorination of TCE occurs in the systems. TCE degradation fits well with pseudo-first-order kinetics. The rate constant of TCE removal increases with increasing current density and persulfate concentration. The presence of 4.210-2 M of Cl- accelerates the degradation of TCE while high concentrations of Cl- and HCO3- (4.2  10-1 M) result in the retardation of TCE removal. HCO3- inhibits TCE degradation more significantly than Cl-. The combination of a persulfate tablet with electrochemical activation achieves >99% TCE removal during 360 min of reaction, which demonstrates the effectiveness of the novel integrated system. Electron paramagnetic resonance analysis confirms the presence of ∙OH, SO4-∙, Cl∙, and ∙CH3 in the system, indicating that TCE is degraded by ∙OH and SO4-∙. The developed electrochemically activated persulfate system is suitable for in situ or on-site remediation of TCE-contaminated groundwater.

Abstract: With the growing demand for water reuse, wastewater treatment facilities must effectively manage emerging contaminants and their byproducts to ensure public safety. Excessive use of benzalkonium chloride disinfectants has raised concerns due to the resulting accumulation of benzylamines, such as N-methylbenzylamine (MBA) and N,N-dimethylbenzylamine (DMBA), in wastewater. In response to increasing emphasis on energy efficiency and carbon reduction, biological anaerobic treatment is gaining popularity. This study investigated the biodegradation of MBA and DMBA under anaerobic conditions, their influence on toxic byproduct formation during subsequent chloramination, and their impact on bioreactor performance, degradation pathways, and microbial community structure. Our findings revealed that anaerobic treatment maintained overall performance despite the presence of benzylamines. However, MBA exhibited significant resistance to biodegradation, while DMBA underwent substantial transformation. Chloramination of MBA-treated effluent resulted in nitroso-MBA formation with a 1% molar yield. In contrast, chloramination of DMBA-treated effluent led to notable N-nitrosodimethylamine (NDMA) formation, with molar yields reaching 10 ± 1% and 97 ± 7% of the influent and residual DMBA concentrations, respectively. Microbial community analysis showed distinct differences in the DMBA reactor compared to the MBA and control reactors, supporting proposed degradation pathways and microbial involvement. To further assess environmental relevance, we collected real water samples from a real wastewater treatment plant in southern Taiwan. Our analyses confirmed the presence of these contaminants and their transformation products in the real treatment processes. Interestingly, preliminary results suggest that aerobic biological treatment may be more effective in degrading benzylamines and suppressing nitrosamine formation. Ongoing investigations aim to elucidate the underlying mechanisms behind these observations.

Abstract: Ammonia borane (AB) is recognized as a stable and safe hydrogen storage material, which renders it particularly advantageous for the advancement of a hydrogen economy. This study successfully demonstrates hydrogen production through the catalytic hydrolysis of AB utilizing cuprous oxide deposited on titanate nanotube arrays (Cu2O/TNAs) within a photoelectrochemical (PEC) system. The synthesis of Cu2O/TNAs was accomplished through the square wave voltammetry electrodeposition (SWVE) technique, followed by comprehensive characterization of their physical and chemical properties. The enhancement of PEC performance can be attributed to the high separation efficiency of electron-hole pairs, a result of the deposition of Cu2O nanoparticles. This phenomenon facilitated hydrogen production during the catalytic hydrolysis of AB. Experimental results indicated that the integration of Cu2O/TNAs with the PEC system constituted the most effective approach for hydrogen generation via catalytic hydrolysis of AB. This efficacy is derived from both the deposition of Cu2O nanoparticles and the synergistic interaction between photocatalysis (PC) and electrocatalysis (EC). Furthermore, a detailed mechanism and pathway for hydrogen production via catalytic hydrolysis of AB using Cu2O/TNAs within the PEC system are proposed to elucidate the involved redox reactions. In conclusion, this research provides substantial contributions to the application of high-performance photocatalysts and technologies for hydrogen production, reinforcing the significance of advancing energy solutions.

Abstract: Seismic performance of tunnels during earthquakes in densely populated areas requires assessing complex interactions with existing infrastructure such as bridges, metro stations facilities, and low- to medium-rise buildings. This has become more challenging because the distance between surface and underground structures has been shortened to optimize the urban environment functionality. This is even more important in transit transfer stations, which usually comprise tunnels, bridges, and buildings, in which wave propagation interference is exacerbated. Key insights gathered from instrumentation of actual structures and numerical parametric studies are presented. A metro station currently under construction, located near by a 5-story masonry building, was selected as a test site for seismic instrumentation. The site is in Mexico City, in the so-called hill zone, where very cemented sandy silt and silty sands is found. An arrangement of five accelerometers were deployed, to assess free-field, near-field, and building seismic response. Some of the results gathered from the seismic instrumentation after recording five low- to high-magnitude earthquakes from both interface and intraplate events are commented. Major findings of the parametric studies are also highlighted. Three-dimensional finite difference models were developed using the software FLAC3D. Initially, the static response of the tunnel was evaluated accounting for the excavation technique. Then, the seismic performance evaluation of the tunnel was carried out, computing ground deformations and factors of safety, considering soil nonlinearities. Good agreement was observed between predicted and observed damage during post-event site observations during actual earthquakes. Once the soundness of the numerical model was established, a numerical study was undertaken to investigate the effect of frequency content in tunnel-induced ground motion incoherence for tunnels built in cemented stiff soils, considering both intraplate and interplate earthquakes, to assess the effect of differences in their frequency content, duration, and intensity. Multiple scenarios were considered in the numerical study, and the relative distances among the structures were varied to investigate both detrimental and beneficial interaction effects, and to identify the zone of influence where this interaction leads to ground motion variability.

Abstract: Computer-aided simulation of tornadoes impacting buildings is an efficient and cost-effective method for studying tornado dynamics. A key challenge in this field is developing physically sound and computationally efficient boundary conditions for tornado scenarios. Building on the success of the immersed-boundary (IB) strategy, this research introduces a novel IB-based framework for investigating tornadic wind effects.

Applying the “relative motion” principle, a tornado approaching a building is reinterpreted as a “virtual” translation of the building - moving with a velocity equal in magnitude but opposite in direction to the tornado’s translation - toward a “virtually pinned” center of purely rotational airflow. This approach simplifies the outer boundary velocity description of the tornado domain by considering only the rotational component, which remains time-independent as long as the boundary is sufficiently far from the building. As a result, computational resources are conserved by eliminating the need for continuous boundary velocity updates. The IB method is then employed to simulate the “virtually moving” building within this framework.

Utilizing the IB strategy alongside the large eddy simulation (LES) model, a computational analysis of tornadic wind loadings on a multi-building configuration was conducted. The findings provide valuable numerical insights that can enhance future simulations of tornadic wind effects.

Abstract: The expansion of tourism mobility associated with globalization has promoted tourism development, but it has also caused tourism pollution and led to the intensification of carbon in the tourism industry. Environmental tourism policies being introduced into the tourism industry do not necessarily lead to realizing sustainable tourism. Here, the industrial upgrading of the manufacturing sector may contribute to sustainable tourism through its ripple effects. Using an R&D-based growth model with heterogeneous firms in the tourism sector including tourism mobility, we investigate the impact of trade-environment tourism policies on economic growth, entry and exit, tourism consumption, and pollution emissions. The results of the analysis show that it is difficult to achieve sustainable tourism through a single policy, as each policy results in a trade-off between the economy, the environment, and tourism. Trade liberalization improves productivity and economic growth through a cleansing effect, but it also causes pollution to increase and tourism to decrease. In this case, reducing pollution and increasing tourism through a tourism tax cut would mitigate the negative effects of trade policy, although it would harm economic growth. An environmental tax would encourage pollution reduction in exchange for a deterioration in productivity. Therefore, we should aim for sustainable tourism through a policy mix of trade liberalization under the policy of environmental tax hikes and tourism tax cuts.

Abstract: Copper is the third most commonly used metal worldwide and is one of the essential elements for modern industrial development. Its widespread applications span industries such as printed circuit board manufacturing and electroplating, resulting in the presence of copper-containing wastewater across numerous sectors. Traditionally, chemical precipitation has been widely employed to remove copper ions from wastewater. However, this method generates sludge with a water content exceeding 90%, necessitating additional downstream processing to reduce moisture content for reuse or disposal. Fluidized Bed Homogeneous Crystallization (FBHC) effectively converts the sludge into high-density granules (with moisture content below 5%) using a single-unit reactor, thereby minimizing the formation of high-moisture sludge and significantly enhancing operational efficiency.

This study investigates the use of industrial-grade NaOH as a precipitant for the removal of copper ions from acidic copper-containing wastewater. The research focuses on optimizing the operational parameters of FBHC for recovering copper metal ions from wastewater. Under optimal conditions, at a pH below 7.0, copper ions can be removed as copper hydroxide with a removal efficiency exceeding 99% and a crystallization ratio of 95%. At a pH above 7.0, copper ions are removed as black copper oxide with a removal efficiency of over 99.9%, reducing the residual copper concentration to below 1.0 mg/L. FBHC facilitates the recovery of valuable resources from etching waste solutions, effectively mitigating resource depletion and environmental pollution, and achieving sustainable waste resource utilization.