Aqueous‐Phase Reforming in a Microreactor: The Role of Surface Bubbles

In heterogeneous catalysis, the creation of gaseous products as bubbles in a liquid phase on the catalytic surface is associated with slip phenomena. In a microreactor, the slip length at the gas‐liquid interface is in the same order of magnitude as the reactor dimensions, which can affect fluid dynamics and transport phenomena. Here, the interplay of momentum, heat and mass transfer in a microreactor, when bubbles form on the catalytic surface, was investigated using two‐dimensional simulations. The effect of bubbles on the endothermic process of aqueous‐phase reforming of a glycerol solution was evaluated in terms of conversion and conversion and temperature in the reactor. Altogether, this study highlights the impact of bubbles, not only on the transport phenomena but also on the reactor performance.     

Multi-physics modeling of doxorubicine binding to ion-exchange resin in blood filtration devices

A group of drugs used in intra-arterial chemotherapy (IAC) have intrinsic ionic properties, which can be used for filtering excessive drugs from blood in order to reduce systemic toxicity. The ion-exchange mechanism is utilized in an endovascular Chemofilter device which can be deployed during the IAC for capturing ionic drugs after they have had their effect on the tumor. In this study, the concentrated solution theory is used to account for the effect of electrochemical forces on the drug transport and adsorption by introducing an effective diffusion coefficient in the advection–diffusion–reaction equation. Consequently, a multi-physics model coupling hemodynamic and electrochemical forces is developed and applied to simulations of the transport and binding of doxorubicine in the Chemofilter device. A comparison of drug adsorption predicted by the computations to that measured in animal studies demonstrated the benefits of using the concentrated solution theory over the Nernst–Plank relations for modeling drug binding.     

煤矿水仓清理新工艺

通过调研现场情况以及检测煤泥特性，探寻一种实用性强、方法简单的新工艺来替代劳累的人工和繁琐的机械清淤，解决现实问题。针对实际情况开发清仓新工艺，介绍了该工艺的技术路线选择、设计依据以及实际应用效果。该新工艺具有降低清仓时间、减轻工人劳动强度、设备操作简单、实用性强等特点。     

Enabling the scale up of green hydrogen in Ireland by decarbonising the haulage sector

The current research on green hydrogen can focus from the perspective of production but understanding the demand side is equally important to the initial creation of a hydrogen ecosystem in countries with low industrial activities that can utilise large amounts of hydrogen in the short term. Early movers in these countries must create a demand market in parallel with the green hydrogen plant commissioning. This paper presents research that explores the heavy-duty transport sector as a market-of-interest for early deployment of green hydrogen in Ireland. Conducting a survey-based market research amongst this sector indicate significant interest in hydrogen on the island of Ireland, and the barriers the participants presented have been overcome in other jurisdictions. The study develops a model to estimate 1.) the annual hydrogen demand and 2.) the corresponding delivery cost to potential hydrogen consumers, either directly or to central hydrogen fuelling hubs.     

Multiphysics modeling of proton exchange membrane water electrolysis: From steady to dynamic behavior

Proton exchange membrane water electrolysis (PEMWE) is currently developed for the design of mature industrial-scale manufactures with commercialization. It needs reducing hydrogen production cost by lowering material cost and increasing operating current density. In engineering perspectives, the study of electrolytic performance during dynamic operation is crucial for PEMWE system management and process control. However, there is few multiphysics models of PEMWE considering transient behavior. The one-dimensional (1D) comprehensive dynamic multiphysics model allows to explore temporal transport phenomena in the PEMWE, and predict electrolytic performance. The 1D model is endorsed by the spatially lumped model from the literature. Changing values of structural and physical properties of porous transport layers (PTLs) and catalyst layers (CLs) allows the observation of their effects on the electrolytic performance and transport phenomena in two-phase flow regime. It suggests that the appropriate PTL properties, and CL fabrication method can lower the cost and remain high electrolytic performance.     

Proton transport of porous triazole-grafted polysulfone membranes for high temperature polymer electrolyte membrane fuel cell

Introduction of porous structure to high temperature polymer electrolyte membranes is one of effective pathways to increase their proton conductivity under elevated temperature. However, the effect of the porous structure on the proton diffusion mechanism of these membranes is still unclear. In this work, the proton transport behaviour of a series of porous triazole-polysulfone (PSf) membranes under elevated temperature is comprehensively investigated. The functional triazole ring in the framework of porous triazole-PSf acts a proton acceptor to form acid-base pair with phosphoric acid (PA). In addition, the proton diffusion coefficient and proton conductivity of PA-doped porous triazole-PSf is an order of magnitude higher than that of the PA-doped dense triazole-PSf membrane. Percolation theory calculation convinces that the high proton conductivity of PA-doped porous triazole-PSf is due to the formation of continuous long-range proton diffusion channels under high pore connectivity and porosity. On the contrary, excessive pore connectivity also results in high gas permeability, leading to decrease of the open circuit voltage and cell performance of the single cell. Consequently, the optimum porosity for the PA-doped porous triazole-PSf membrane is 75% for fuel cell operating with the maximum peak power density of 550 mW·cm^?2 and great durability for 120 h under 140 °C.     

Electrospinning derivative fabrication of sandwich-structured CNF/Co3S4/MoS2 as self-supported electrodes to accelerate electron transport in HER

The substitution of noble metal catalysts with earth abundant TMs as electrocatalysts for hydrogen production is of great significance. One biggest bottleneck for high-efficiency water electrolysis in TM catalysts is the sluggish reaction kinetics or electron transport efficiency. The electrical coupling between the substrate and the catalytic material can accelerate the electron transport, enhancing the charge transfer kinetics, and thereby improve the catalytic performance of the catalyst. Herein, we report a sandwich-structured CNF/Co₃S₄/MoS₂, MoS₂ grown in-situ on N-doped nanofibers with Co₃S₄ nanoparticles via electrospinning, carbonization and hydrothermal process, as self-supported electrodes for hydrogen evolution reaction. The sandwich structure is comprised of CNFs/Co₃S₄/MoS₂ as substrate/accelerator/catalyst. Thereinto, the three-dimensional CNF framework, intrinsically doped by nitrogen, can open accessible channels for reactants and served as substrates for the in-situ growth of Co₃S₄ and MoS₂ nanocrystals with high conductivity and massive active sites. Hence, the CNF/Co₃S₄/MoS₂ shows outstanding catalytical performance in water electrospinning, only 80 mV required to drive 10 mA cm^?2 current density with the Tafel slope of 99.2 mV dec^?1 in alkaline media. Besides, the performance can be maintained for at least 40 h with negligible decline. This experiment can provide a new idea for the design of efficient and stable self-supporting electrodes.     

Advancements and current technologies on hydrogen fuel cell applications for marine vehicles

Maritime industry has led renewable energy sources for the greener environment and efficient vehicles that effect by increasing population and energy demands. Hydrogen is one of the most popular of these renewable energy sources and one of the most favourable research area, worldwide. In this study, authors reported the usage of hydrogen fuel cells in marine transport as main power forwarder, their advantages and challenges under the lights on state of art and furthermore new technologies perspective. The latest research activities, hydrogen production and storage methods with challenges are analyzed and the developments of fuel cell based marine vehicles are discussed. In detailed, newly approachment of electrolyses from seawater for sustainable fuel necessity is discussed. As a result, this forseen study is important in terms of handling energy from seawater and compiling the latest technology for marine transport.     

Time-independent charge carrier mobility in a model polymer:fullerene organic solar cell

The technique of photo-CELIV (charge extraction by linearly increasing voltage) is one of the more straightforward and popular approaches to measure the faster carrier mobility in measurement geometries that are relevant for operational solar cells and other optoelectronic devices. It has been used to demonstrate a time-dependent photocarrier mobility in pristine polymers, attributed to energetic relaxation within the density of states. Conversely, in solar cell blends, the presence or absence of such energetic relaxation on transport timescales remains under debate. We developed a complete numerical model and performed photo-CELIV experiments on the model high efficiency organic solar cell blend poly[3,6-dithiophene-2-yl-2,5-di(2-octyldodecyl)-pyrrolo[3,4-c]pyrrole-1,4-dione-alt-naphthalene] (PDPP-TNT):[6,6]-phenyl-C₇₁-butyric-acid-methyl-ester (PC70BM). In the studied solar cells a constant, time-independent mobility on the scale relevant to charge extraction was observed, where thermalisation of photocarriers occurs on time scales much shorter than the transit time. Therefore, photocarrier relaxation effects are insignificant for charge transport in these efficient photovoltaic devices.