4,820 research outputs found

    A high specific capacity membraneless aluminum-air cell operated with an inorganic/organic hybrid electrolyte

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    Aluminum-air cells have attracted a lot of interests because they have the highest volumetric capacity density in theory among the different metal-air systems. To overcome the self-discharge issue of aluminum, a microfluidic aluminum-air cell working with KOH methanol-based anolyte was developed in this work. A specific capacity up to 2507 mAh g¯¹ (that is, 84.1% of the theoretical value) was achieved experimentally. The KOH concentration and water content in the methanol-based anolyte were found to have direct influence on the cell performance. A possible mechanism of the aluminum reactions in KOH methanol-based electrolyte was proposed to explain the observed phenomenon

    Comparative energetic assessment of methanol production from COâ‚‚: chemical versus electrochemical process

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    Emerging emission-to-liquid (eTL) technologies that produce liquid fuels from COâ‚‚ are a possible solution for both the global issues of greenhouse gas emissions and fossil fuel depletion. Among those technologies, COâ‚‚ hydrogenation and high-temperature COâ‚‚ electrolysis are two promising options suitable for large-scale applications. In this study, two COâ‚‚ -to-methanol conversion processes, i.e., production of methanol by COâ‚‚ hydrogenation and production of methanol based on high-temperature COâ‚‚ electrolysis, are simulated using Aspen HYSYS. With Aspen Energy Analyzer, heat exchanger networks are optimized and minimal energy requirements are determined for the two different processes. The two processes are compared in terms of energy requirement and climate impact. It is found that the methanol production based on COâ‚‚ electrolysis has an energy efficiency of 41%, almost double that of the COâ‚‚ hydrogenation process provided that the required hydrogen is sourced from water electrolysis. The hydrogenation process produces more COâ‚‚ when fossil fuel energy sources are used, but can result in more negative COâ‚‚ emissions with renewable energies. The study reveals that both of the eTL processes can outperform the conventional fossil-fuel-based methanol production process in climate impacts as long as the renewable energy sources are implemented

    Macroporous materials: microfluidic fabrication, functionalization and applications

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    This article provides an up-to-date highly comprehensive overview (594 references) on the state of the art of the synthesis and design of macroporous materials using microfluidics and their applications in different fields

    In situ photogalvanic acceleration of optofluidic kinetics: a new paradigm for advanced photocatalytic technologies

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    A multiscale-designed optofluidic reactor is demonstrated in this work, featuring an overall reaction rate constant of 1.32 s¯¹ for photocatalytic decolourization of methylene blue, which is an order of magnitude higher as compared to literature records. A novel performance-enhancement mechanism of microscale in situ photogalvanic acceleration was found to be the main reason for the superior optofluidic performance in the photocatalytic degradation of dyes as a model reaction

    Rational design of photoelectrochemical cells towards bias-free water splitting: Thermodynamic and kinetic insights

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    Photoelectrochemical (PEC) water splitting offers a promising way to produce hydrogen and harvest solar energy, however, its low efficiency has made it less economically attractive than other hydrogen production methods. Herein we present a numerical model of PEC cells considering quasi-fermi level splitting and interfacial kinetics to understand the charge transfer process and explore the approaches to increase the energy conversion efficiency. The non-linear change of photocurrent with light intensity under concentrated illumination is for the first time captured by a model. Based on the model, the operation regions of a PEC cell are mapped. Pathways to further promote the energy efficiency of PEC are proposed from the aspect of kinetics and thermodynamics. A new method that enables a precise evaluation of the theoretical boundaries of energy conversion efficiency of photocatalysts is developed taking into account the thermodynamics barrier

    Polymeric templating synthesis of anatase TiOâ‚‚ nanoparticles from low-cost inorganic titanium sources

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    A novel facile and cost-effective synthesis method for anatase TiOâ‚‚ nanoparticles has been developed by using poly-acrylic acid hydrogel as template at room temperature. The newly developed synthesis method avoids the use of hazardous reagents and/or hydrothermal steps, and enables production of highly active TiOâ‚‚ nanoparticles from low cost inorganic titanium sources. The synthesized TiOâ‚‚ nanoparticles have been studied in several applications including dye-sensitized solar cells as a photoanode as well as in organics degradation of methyl orange in aqueous media. Good photocatalytic performances were obtained in both applications

    Computational comparison of two mouse draft genomes and the human golden path

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    BACKGROUND: The availability of both mouse and human draft genomes has marked the beginning of a new era of comparative mammalian genomics. The two available mouse genome assemblies, from the public mouse genome sequencing consortium and Celera Genomics, were obtained using different clone libraries and different assembly methods. RESULTS: We present here a critical comparison of the two latest mouse genome assemblies. The utility of the combined genomes is further demonstrated by comparing them with the human 'golden path' and through a subsequent analysis of a resulting conserved sequence element (CSE) database, which allows us to identify over 6,000 potential novel genes and to derive independent estimates of the number of human protein-coding genes. CONCLUSION: The Celera and public mouse assemblies differ in about 10% of the mouse genome. Each assembly has advantages over the other: Celera has higher accuracy in base-pairs and overall higher coverage of the genome; the public assembly, however, has higher sequence quality in some newly finished bacterial artificial chromosome clone (BAC) regions and the data are freely accessible. Perhaps most important, by combining both assemblies, we can get a better annotation of the human genome; in particular, we can obtain the most complete set of CSEs, one third of which are related to known genes and some others are related to other functional genomic regions. More than half the CSEs are of unknown function. From the CSEs, we estimate the total number of human protein-coding genes to be about 40,000. This searchable publicly available online CSEdb will expedite new discoveries through comparative genomics
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