In this study, one‐pot hydrothermal synthesis of sheet‐like ZSM‐5 as a high‐performance catalyst for toluene disproportionation was carried out using binary surfactants. In the dual template, ...tetraethylammonium hydroxide was used to construct the microporous structure of ZSM‐5, and cationic surfactant (e.g., octadecyltrimethylammonium chloride (C18TMAC), hexadecyltrimethyl ammonium bromide (C16TMAB), and tetradecyltrimethylammonium bromide, (C14TMAB)) can change the growth habits of the ZSM‐5 crystals by hindering the regular stacking of zeolite layers from their longer hydrophobic chain. From the XRD pattern of the as‐synthesized samples which were hydrothermally treated for different time, it was found that a lamellar mesostructured intermediate gradually transformed into the sheet‐like ZSM‐5 during hydrothermal process. With a proper amount of cationic surfactant, the thickness of the sheet‐like ZSM‐5 could be controlled to less than 30 nm. Concerning the catalyst application, the toluene disproportionation performance over the sheet‐like ZSM‐5 is 1.5 times higher than that of the commercial ZSM‐5. The higher conversion is ascribed to the faster diffusion amount due to the sheet‐like ZSM‐5.
In this study, one‐pot hydrothermal synthesis of sheet‐like ZSM‐5 as a high‐performance catalyst for toluene disproportionation was carried out using binary surfactants.
•Integrated simulation framework consisting of COMSOL and Simulink models.•Hydrogen supply stability and recovery performance of a PEMFC system.•A lower ejector temperature is disadvantageous in ...removing the moisture content.•Passive Venturi ejector to perform hydrogen recovery significantly reduces the time required.
In traditional PEM fuel cells (PEMFCs), the unreacted hydrogen gas at the anode outlet is recovered using a mechanical pump or centrifuge and returned to the inlet side for reuse. However, the energy consumed by the pump reduces the system efficiency. Accordingly, the present study considers a 3-kW PEMFC in which the unreacted hydrogen gas is recovered passively from the exhaust stream using a Venturi ejector. An integrated simulation framework is constructed consisting of a COMSOL model of the ejector unit and a MATLAB/Simulink model of the hydrogen recovery system. The simulation framework is used to examine the temperature, pressure and velocity distributions within the ejector for various values of the inlet hydrogen pressure. The stability of the hydrogen supply in PEMFC systems incorporating a passive ejector system and a traditional mechanical hydrogen recovery system, respectively, is then investigated and compared. It is shown that the ejector stabilizes the hydrogen supply more quickly than the traditional mechanical system. As a result, it not only improves the hydrogen utilization rate and environmental safety of the PEMFC system, but also reduces the overall hydrogen consumption. The simulation results for the I-V performance of the PEMFC with the Venturi ejector are shown to be in good qualitative agreement with the experimental results. Overall, the numerical framework constructed in the present study provides a useful tool for exploring the effects of the ejector design parameters on the hydrogen recovery performance and determining the operating conditions which maximize the performance of the PEMFC system.
Materials
Multiporous carbon (MPC) with a high specific surface area (1121 m2g−1) and mesoporous and microporous structures was prepared by using bamboo biochar (308 m2g−1) as raw material.
Methods
...The preparation involved a CaCO3 activation process, where CaCO3 served as both the template for mesopores and the activating agent for micropores. The template could be easily removed by dilute HCl(aq) solution, making the preparation process simpler and more environmentally friendly compared to using mesoporous SiO2 as a hard template.
Results
The performance of the MPC and biochar as adsorbents for methyl orange (MO) dye was investigated by means of thermal dynamic isotherms and kinetic models tests. The Langmuir isothermal analysis results revealed that the MPC exhibited a significantly higher MO adsorption capacity (344.8 mg g−1) compared to the bamboo biochar (12.4 mg g−1). The adsorption kinetics of the MPC followed a pseudo‐second‐order model.
Conclusion
Overall, the obtained MPC material offers a cost‐effective, environmentally friendly, and efficient solution for removing dyes from aqueous solutions.
Multiporous carbon with a high specific surface area (1121 m2g−1) and mixed mesopore and micropore structure were prepared from bamboo biochar with a specific surface area of 308 m2g−1 via CaCO3 activation.
•Effect of N2O decomposition on soot formation in N2O/C2H4 flame was examined.•Thermal effect of N2O decomposition on soot formation increased with the R value.•The oxy-enrichment effect on soot ...formation increased gradually.•Soot formation and oxidation rate rebalances under the N2O decomposition effect.
This study experimentally investigated the effect of nitrous oxide (N2O) decomposition on soot formation in N2O/ethylene diffusion flames. The effect of N2O decomposition on the soot formation mechanism was examined in three oxidation cases (Cases Case I–III). In Case I, N2O was used as the oxidant; in Case II, an oxygen-enriched N2/O2 mixture (67 % N2 + 33 % O2) was used as the oxidant; and in Case III, standard air (79 % N2 + 21 % O2) was used as the oxidant. A triple-port burner was used to generate diffusion flames with various R (ratio of the oxidizer flow velocity to the fuel flow velocity) values (R = 0–6). The soot concentration was measured through laser-induced incandescence, and the soot temperature was determined using two-color pyrometry. The measured soot temperatures increased significantly due to the thermal effect in the upstream position of the N2O/C2H4 flames. The oxygen-enrichment effect on soot formation increased gradually from 10 % to 60 % as R increased from 0.5 to 6. The integration of the soot concentration along the flame length revealed that the soot formation rate and soot oxidation rate might rebalance under the N2O decomposition effect.
A variety of human diseases transmitted by arthropod vectors, including ticks, are emerging around the globe. Birds are known to be hosts of ticks and can disperse exotic ticks and tick-borne ...pathogens. In Taiwan, previous studies have focused predominantly on mammals, leaving the role of birds in the maintenance of ticks and dissemination of tick-borne pathogens undetermined.
Ticks were collected opportunistically when birds were studied from 1995 to 2013. Furthermore, to improve knowledge on the prevalence and mean load of tick infestation on birds in Taiwan, ticks were thoroughly searched for when birds were mist-netted at seven sites between September 2014 and April 2016 in eastern Taiwan. Ticks were identified based on both morphological and molecular information and were screened for potential tick-borne pathogens, including the genera Anaplasma, Babesia, Borrelia, Ehrlichia and Rickettsia. Finally, a list of hard tick species collected from birds in Taiwan was compiled based on past work and the current study.
Nineteen ticks (all larvae) were recovered from four of the 3096 unique mist-netted bird individuals, yielding a mean load of 0.006 ticks/individual and an overall prevalence of 0.13%. A total of 139 ticks from birds, comprising 48 larvae, 35 nymphs, 55 adults and one individual of unknown life stage, were collected from 1995 to 2016, and 11 species of four genera were identified, including three newly recorded species (Haemaphysalis wellingtoni, Ixodes columnae and Ixodes turdus). A total of eight tick-borne pathogens were detected, with five species (Borrelia turdi, Anaplasma sp. clone BJ01, Ehrlichia sp. BL157-9, Rickettsia helvetica and Rickettsia monacensis) not previously isolated in Taiwan. Overall, 16 tick species of five genera have been recorded feeding on birds, including nine species first discovered in this study.
Our study demonstrates the paucity of information on ticks of birds and emphasizes the need for more research on ticks of birds in Taiwan and Southeast Asia. Moreover, some newly recorded ticks and tick-borne pathogens were found only on migratory birds, demonstrating the necessity of further surveillance on these highly mobile species.
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•Bio-methanol is employed as a feedstock for H2 produciton from bio-methanol steam reforming.•Cu-Ni / aluminate composites without organic template is used as catalysts to produces ...H2.•ANOVA analysis reveals that temperature is the primary factor affecting H2 productivity.•The catalysts achieve 100% bio-methanoal conversion and 2.93 mol / mol CH3OH H2 yield.•Long-term tests confirm the catalysts’ stability and effectivenes as a commercial one.
Hydrogen has emerged its importance for decarbonization to approach net-zero emissions in 2050. This study aims to develop three highly-porous Ni-Cu/Al2O3 catalysts (Ni-to-Cu weight ratio = 10 %, 20 %, and 30 %) for hydrogen production from the steam reforming of “Green” methanol (or bio-methanol). The prepared catalysts require no organic templates, thereby efficiently reducing unnecessary costs. With Taguchi orthogonal array design and analysis of variance (ANOVA), the impacts of selected operating factors on hydrogen productivity under ultrasonic sprays are investigated. The results reveal that the carrier gas flow rate is the most influential factor in H2 yield at the steam-to-methanol molar ratio (S/C) of 1.5, whereas the temperature is the most impactful factor at S/C = 2.0. The regression between the Taguchi effect value and the ANOVA F value develops a strong linear relationship. The optimal experimental conditions of Ni-Cu(30 %)/Al2O3, reaction temperature of 300 °C, N2 flow rate of 1,000 mL⋅min−1, and S/C = 2.0, achieve 100 % methanol conversion, 39.74 vol% H2 concentration in the product gas, and 2.93 mol⋅(mol CH3OH)-1 H2 yield. Thes data also show superior performance compared to those in the literature. In long-term stability tests, the prepared catalysts also exhibit high stability and effectiveness commensurate with commercialized Cu-based catalysts.
Materials
In this study, we provided a simple method to extract the silicate species from the waste silica‐containing molding compounds from the semiconducting industry.
Methods
Recycled sodium ...silicate solution was obtained from alkaline extraction of the silica fillers in the waste molding compounds and dried and redissolved in appropriate amount of water.
Results
Porous silica of high surface area (>500 m2g−1) and tunable pore size (1.5–5.0 nm) could be feasibly synthesized by using the recycled sodium silicate as silica source and nature‐friendly homopolymer polyethylene glycol (PEG) as an organic template. The pore size of the PEG‐templating silicas was made tunable by hydrothermal treatment at different pH.
Conclusion
To reduce the emission of CO2 gas from the removal of the PEG template, porous silica with a large surface area has been prepared at a low PEG/sodium silicate weight ratio of 1/20.
This study extracted silicate species from waste silica‐containing molding compounds in the semiconductor industry. Using this recycled sodium silicate as the silica source and eco‐friendly polyethylene glycol (PEG) as an organic template, porous silica with a high surface area (>500 m2g−1) and adjustable pore size (1.5–5.0 nm) can be synthesized.
In recent years, the application of low-refractive-index materials in the optical field has attracted considerable attention due to it high transmittance and high optical sensitivity. In this study, ...we synthesized SiO2 porous hollow spheres (SPHS) with an ultralow refractive index (n = 1.05) by using a templating method. Their refractive indices could be easily controlled from 1.05 to 1.08 by tuning the thickness of shell. In addition, a droplet coatings method is proposed for SPHS colloidal crystal (CC) by controlling the temperature and humidity. The SPHS CCs displayed distinct structural colors when the incident angle was adjusted and demonstrated high angular resolution. Moreover, the iridescent color changes could be observed with the naked eye. For surface-enhanced Raman scattering application, more analyte could be absorbed by the porous shells, and metal nanoparticles were coated on the SPHSs surface to increase the hot spot density for improving the SERS intensity.
The opportunity to host international sporting events is an important milestone for advanced countries, and transportation services play a significant role at such events. This study applies the Kano ...model to evaluate passengers’ satisfaction with each service element at a mega event. Furthermore, it explores various transportation modes (i.e., buses and cars) according to passenger group (collectively and individually), and accordingly, ranks service elements requiring improvement. The findings show that sufficient transportation services to the desired destination are considered a fundamental service at a mega sport event. Although the ability of drivers to communicate in English is neither demanded nor anticipated, they are expected to be friendly towards passengers. Compared with car passengers, bus passengers place greater value on clear transportation information, sufficient transportation frequency, and other internet-related functions such as free Wi-Fi on the bus and free apps for transportation reservations and destination navigation. Good complaint management, straightforward reservation systems, vehicle tidiness, sufficient transportation frequency, and clear transportation information are considered critical services. Organizers must therefore prioritize these services for improvement.
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