RESUMEN
Thermophotovoltaic (TPV) generators provide continuous and high-efficiency power output by utilizing local thermal emitters to convert energy from various sources to thermal radiation matching the bandgaps of photovoltaic cells. Lack of effective guidelines for thermal emission control at high temperatures, poor thermal stability, and limited fabrication scalability are the three key challenges for the practical deployment of TPV devices. Here we develop a hierarchical sequential-learning optimization framework and experimentally realize a 6â³ module-scale polaritonic thermal emitter with bandwidth-controlled thermal emission as well as excellent thermal stability at 1473 K. The 300 nm bandwidth thermal emission is realized by a complex photon polariton based on the superposition of Tamm plasmon polariton and surface plasmon polariton. We experimentally achieve a spectral efficiency of 65.6% (wavelength range of 0.4-8 µm) with statistical deviation less than 4% over the 6â³ emitter, demonstrating industrial-level reliability for module-scale TPV applications.
RESUMEN
Sulfur dioxide (SO2) mitigation and water treatment are two key aspects towards a sustainable environment, and simultaneous achievement of these two goals is extremely attractive. Inspired by the iron ion catalyzed auto-oxidation of aqueous SO2 (i.e., Fe(II)/sulfite process), that generates intermediary sulfate radical able to oxidize organic compounds, we propose a feasible energy-water-environment nexus by using waste SO2 to alleviate water contamination. As a demonstration, electrolysis is used to assist Fe(II)/sulfite (i.e., electro/Fe(II)/sulfite) process to enhance contaminant removals. Results showed 91% of 10 µM ibuprofen (a nonsteroidal anti-inflammatory drug) contaminant at neutral pH was removed, due to sulfate radical oxidation. Synergy mechanisms of electro/Fe(II)/sulfite process were revealed. Moreover, the electro/Fe(II)/sulfite process could effectively degrade contaminants in water bodies from fields, indicating its promising practical application. Energetic analysis indicated that electric treatment cost is 8.65 cent/m3, and is affordable by most water treatment plants. Possible procedures to realize the proposed energy-water-environment nexus were also suggested. The strategy proposed in this study adds new value to the waste produced in energy production and will create renewed interest considering its potential use towards environmental treatment.
RESUMEN
Gel systems are widely used as plugging materials in the oil and gas industry. Gas channeling can be mitigated by reducing the heterogeneity of the formation and the mobility ratio of CO2 to crude oil. Cracks and other CO2 leaking pathways can be plugged during the geological storage of CO2 to increase the storage stability. By adding CO2-responsive groups to the classic polymer gel's molecular chain, CO2 responsive gel is able to seal and recognize CO2 in the formation while maintaining the superior performance of traditional polymer gel. The application of CO2 responsive gels in oil and gas production is still in the stage of laboratory testing on the whole. To actually achieve the commercial application of CO2 responsive gels in the oil and gas industry, it is imperative to thoroughly understand the CO2 responsive mechanisms of the various types of CO2 responsive gels, as well as the advantages and drawbacks of the gels and the direction of future development prospects. This work provides an overview of the research progress and response mechanisms of various types of CO2 responsive groups and CO2 responsive gels. Studies of the CO2 responsive gel development, injectivity, and plugging performance are comprehensively reviewed and summarized. The shortcomings of the existing CO2 responsive gels system are discussed and the paths for future CO2 responsive gel development are suggested.
RESUMEN
Based on Volcano plotting, the controlled combination of weak and strong bond strengths of a bimetallic catalyst has the potential to maximize the catalytic effect via the formation of intermediate bond strength between the reactant and the two different types of active sites. In this study, a rational design approach was adopted to couple MoO3 and CeO2 to maximize the catalytic oxidation of Hg0 using oxygen as the oxidizing agent. It is found that CeO2 displayed a relatively strong bond strength with Hg0 while MoO3 has relatively weak bond strength with Hg0; the pre-doping of MoO3 results in the transformation of CeO2 from clusters to the form with additional exposed CeO2 (111) surface; the CeO2 and MoO3 show synergistic effect on the formation of Brønsted acid sites. Moreover, the results show that there is an overlap between the Hg0 desorption region of MoO3 and the Hg0 adsorption region of CeO2 (with adjusted optimum bond strength with Hg0), which contributes to the catalytic reaction of Hg0 by O2. Therefore, this study reveals that the synergistic effects of the coupling of CeO2 and MoO3 induced the reaction between Hg0 and O2, which is otherwise difficult.
RESUMEN
BACKGROUND: The study was conducted to investigate the current status of the occupational health and safety management system (OHSMS) in the construction industry and the effect of OHSMS on accident rates. Differences of awareness levels on safety issues among site general managers and occupational health and safety (OHS) managers are identified through surveys. METHODS: The accident rates for the OHSMS-certified construction companies from 2006 to 2011, when the construction OHSMS became widely available, were analyzed to understand the effect of OHSMS on the work-related injury rates in the construction industry. The Korea Occupational Safety and Health Agency 18001 is the certification to these companies performing OHSMS in South Korea. The questionnaire was created to analyze the differences of OHSMS awareness between site general managers and OHS managers of construction companies. RESULTS: The implementation of OHSMS among the top 100 construction companies in South Korea shows that the accident rate decreased by 67% and the fatal accident rate decreased by 10.3% during the period from 2006 to 2011. The survey in this study shows different OHSMS awareness levels between site general managers and OHS managers. The differences were motivation for developing OHSMS, external support needed for implementing OHSMS, problems and effectiveness of implementing OHSMS. CONCLUSION: Both work-related accident and fatal accident rates were found to be significantly reduced by implementing OHSMS in this study. The differences of OHSMS awareness between site general managers and OHS managers were identified through a survey. The effect of these differences on safety and other benefits warrants further research with proper data collection.