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High-temperature proton exchange membrane fuel cells (HT-PEMFC) have strong resistance to CO poisoning. However, the published CO poisoning models for HT-PEMFC are based on the finite element analysis method, which are difficult to use for the performance prediction and development of system control strategies due to a large amount of calculation. In the beginning, a semi-empirical model of HT-PEMFC is deduced based on the analysis of the CO poisoning characteristics. Then the key parameters of ohmic impedance and concentration polarization advance correction factor are obtained by fitting the polarization curves, dissociation and adsorption activation energy of H 2 and CO are obtained by the calculation, respectively. The slope of the straight line segment in the ohmic polarization interval of the polarization curve is linearly related to ln [H 2 /CO]. The change of limiting current density is the main factor for the advance of concentration polarization. The fitted ohmic impedance varies with temperature and CO concentration, but changes little above 175 °C. CO coverage depends primarily on dissociation and adsorption activation energy of CO. Subsequently, the proposed model is validated with experimental data and shows high similarity. The model can be used for studying the systematic control strategy development and performance monitoring of HT-PEMFC. • A model with a wider range of temperature and CO concentration was established. • The ohmic impedance is not only related to temperature but also CO concentration. • The slope of the straight line segment of the V–I curve is linearly with ln [H 2 /CO]. • The change of CO dissociation and the adsorption activation energy was deduced. [ABSTRACT FROM AUTHOR]

• EIS is applied for SOEC model validation and operating strategy investigation. • Proposed a segmented fuel strategy to extend the dynamic range from 130 % to 163 %. • Region statistic method is proposed to study the effect of air inlet temperature. • Inlet temperature and flow rate are discussed in the air operating strategy. • A hybrid strategy is proposed to further increase the dynamic range to 170 %. The solid oxide electrolysis cell technology can be integrated with intermittent power sources such as wind to produce hydrogen by water electrolysis for electrical energy storage. However, the fluctuation of wind power may induce transient variations in the electrochemical and thermal performances of the solid oxide electrolysis cell. Applying active operation strategies helps improve the transient performances of the electrolysis cell under large-scale dynamic electrical inputs. In this study, a three-dimensional electrochemical-mass-heat coupling dynamic model of the solid oxide electrolysis cell with voltage-current curve and electrochemical impedance validation is developed to investigate the effects of different active operation strategies. The mechanism and feasibility of the fuel and air operation strategies in the current fluctuation are examined based on the electrochemical, concentration, and temperature responses. The optimized active fuel operating strategy is capable of achieving a dynamic range of 0–163 %. The effectiveness of the air operating strategy depends on the preheating temperature and flow rate of the air, and their selection requires a balance between temperature control ability and temperature gradient. Integrating the advantages of both fuel and air operation strategies, a fuel–air hybrid operating strategy is proposed to further increase the dynamic range to 0–170 %. [ABSTRACT FROM AUTHOR]

• Conversion of plastic waste into biofuel by pyrolysis was compressively reviewed. • Effects of conditions, catalyst, plastic, and reactor type on biofuel were discussed. • The state-of-the-art of machine learning in plastic pyrolysis was reviewed. • A critical discussion of recent challenges with future perspectives was presented. It is urgent to promote the technology development of plastic waste (PW) valorization to mitigate the present serious plastic pollution. Pyrolysis has been widely used to convert PW into high-value-added products, especially liquid fuels, in a sustainable manner. However, achieving a high yield of liquid fuel with good quality remains challenging due to the difficulty in optimizing pyrolysis process and synthesizing outstanding catalysts to narrow the product distribution. This work comprehensively reviewed PW pyrolysis from both technical and computational (machine learning modeling) aspects, with a critical discussion of recent challenges to find new insights for improving the conversion efficiency and promoting commercialization. Results indicated that the impacts of various factors, including PW type, process condition, catalyst, and reactor type, on the PW pyrolysis were extensively investigated by the research community. Machine learning methods have also been frequently applied to predict, interpret, and optimize the PW pyrolysis. However, more efforts can be made in the future regarding catalyst synthesis, selection of co-pyrolysis additives, mechanism of catalyst deactivation, and design of renewable energy supply system for PW pyrolysis plants. Additionally, more attention should be paid to enlarging the data size, improving model interpretability, and exploring innovative ways of machine learning application (e.g., active learning) in process optimization and catalyst design for PW pyrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • First 3D open-source pore-scale modeling of pure and composite MIEC cathodes. • Well validated pore-scale electrochemical open-source model framework is developed. • Evaluation under high current density, low operating temperature, and low P O2. • Local TPB/DPB current densities analysis at the pixel level. • Composite LSCF/GDC cathode with 20–40 μm thickness is recommended. Composite engineering is one of the most practical strategies for mitigating thermo-mechanical instability in state-of-the-art cobalt-based mixed ionic-electronic conducting electrodes for solid oxide cells. Nevertheless, the mechanism underlying improved performance and durability of composite electrodes is not substantially examined and understood. Pore-scale modeling can effectively bridge the gap between material property, microstructure discovery, and performance evaluation. However, most of the previous pore-scale models are built on in-house codes or commercial software that is closed-source to the public, limiting customization and community involvement. Here we report for the first time a microstructure-resolved 3D pore-scale model based on an open-source Lattice Boltzmann library, implementing a well-validated electrochemical module that considers gas, ion and electron transport, as well as electrochemical reaction at triple-phase-boundary (TPB) and double-phase-boundary (DPB). The pure La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) and 50/50 vol% composite LSCF/GDC (Gd-doped ceria) cathodes are reconstructed using focused ion beam-scanning electron microscopy and then are investigated under various current densities, temperatures, oxygen concentrations, and thicknesses. Results reveal the advantages of boosted TPB density and ionic conductivity outweigh the disadvantages of lower DPB density and electronic conductivity for the composite cathode. Furthermore, the composite cathode performs better at low temperatures and low oxygen concentrations due to the presence of more macropores, the stable bulk ion conductivity of GDC, and higher TPB density. Local current distribution at active sites indicates a thickness of 20 to 40 μm is favorable for reduced overpotential and moderate reaction homogeneity. [ABSTRACT FROM AUTHOR]

• ReaxFF simulation and experiments shows that methanol and ethanol can increase the initial cracking temperature of n-decane. • Adding methanol and ethanol change the first-step cracking product species of n-decane pyrolysis from C 3 H 7 + C 7 H 15 to C 5 H 11 + C 5 H 11. • C7-C9 fragments are non-accumulated intermediates, and C2 is the main existence forms of products. • Methanol can be decomposed into HO and CH 3, CH 3 O and H. Ethanol can be decomposed into C 2 H 4 and H 2 O, CH 3 O and CH 3 , C 2 H 5 O and H. Alcohol assisted hydrocarbon fuels regenerative cooling is a promising method to deal with scramjet engine heat management of hypersonic flight vehicle. To reveal the effect of alcohol on hydrocarbon fuels pyrolysis pathway, ReaxFF molecular dynamics simulation was done to investigate the variation of intermediate fragments in methanol/ethanol assisted n-decane pyrolysis process. Results shows that, two alcohols increase the initial cracking temperature of n-decane. Two alcohols turn the first-step cracking products of n-decane from C 3 H 7 + C 7 H 15 to C 5 H 11 + C 5 H 11 , and make n-decane cracking into C 2 H 5 + C 8 H 17 possible. Initial pyrolysis of n-decane with methanol and ethanol can be coupled by CH 3 and C 2 H 5 free radical respectively. In the subsequent pyrolysis process, C10 are completely consumed within 10 ps. C7-C9 fragments are transient intermediates and can hardly accumulate. Experiment indicates that 450–500 °C is the decisive temperature range for n-decane cracking, and adding methanol or ethanol increase the initial cracking temperature of n-decane pyrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • The segmented SOFC is tested under direct internal reforming of hythane. • In-plane current and temperature of the DIR SOFC are simultaneously measured. • Local electrochemical processes are clarified by several EIS analysis approaches. • Enhancement in all segments can be achieved by a modest H 2 blending. • Thermal neutral state can be achieved at a current density of 300 mA cm−2. The solid oxide fuel cell with direct internal reforming is promising for cost-effective utilization of hythane produced by blending hydrogen in natural gas. Deep understanding of the inhomogeneous distributions of physiochemical processes is essential to assist in optimization of hythane-fueled fuel cell. In this work, the effects of H 2 blending ratio and steam-to-carbon ratio on local electrochemical performance and temperature of a segmented cell are comprehensively examined. Local electrochemical processes are clarified by various electrochemical impedance spectroscopy investigation approaches including analysis of differences in impedance spectra, distribution of relaxation times, and equivalent circuit model fitting. H 2 blending reduces the concentration overpotential significantly while also homogenizing the reforming distribution and promoting the anodic electrochemical process in all segments. H 2 blending ratio above 20 % greatly reduces the cold spots induced by endothermic reforming but results in hot spots in the gas outlet when the voltage is below 0.7 V because of high electrochemical reaction heat. Regardless of the H 2 blending or steam-to-carbon ratio, a nearly thermal neutral state is observed at current density of 300 mA cm−2. These findings demonstrate the potential of boosting performance and simultaneously maintaining homogeneous temperature in the direct internal reforming solid oxide fuel cells. [ABSTRACT FROM AUTHOR]

• 3D model including elementary reaction kinetics for HT-PEMFCs is developed. • Adsorption and desorption of H 2 and CO are considered. • Sensitivities of elementary reaction rates are analyzed at various conditions. • Distributions of gaseous and surface species are obtained and discussed. • Influences of CO content and operating temperature are analyzed. High-temperature proton exchange membrane fuel cells have received lots of attention due to their high tolerance of impurities in the fuel gas. Many researchers have conducted experimental and numerical investigations to study the influence of carbon monoxide on performance of the high-temperature proton exchange membrane fuel cell. However, most numerical models use an empirical formula to consider the effect of adsorption and desorption of hydrogen and carbon monoxide. To more accurately study the influence mechanism of carbon monoxide as an impurity, a novel three-dimensional non-isothermal model considering elementary reactions of hydrogen and carbon monoxide for high-temperature proton exchange membrane fuel cells is developed in this study. The elementary reaction kinetics of the anodic catalytic layer adopts a six-step global reaction, and the adsorption processes, desorption processes, as well as electrochemical reactions are taken into account. This model is able to accurately predict the steady polarization curve of a high-temperature proton exchange membrane fuel cell fed by hydrogen containing different amounts of carbon monoxide. The sensitivities of elementary reaction rates in the voltage range of 0.4–0.9 V for the fuel cell fed by pure hydrogen or a mixture of hydrogen and carbon monoxide are analyzed. The rate-determination step is studied at different voltages. In addition, the distributions of gaseous species, surface species and reaction rates of all elementary reactions along different directions of the anode catalytic layer are presented. Finally, the influences of carbon monoxide content in the fuel gas and the operating temperature of a high-temperature proton exchange membrane fuel cell fed by a mixture of hydrogen and carbon monoxide are numerically studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel microchannel heat sink(MHS) with serpentine reentrant microchannels(SRM) were developed. • MHS with SRM provided efficient cooling for high concentration photovoltaic(HCPV) cells. • MHS with SRM reduced HCPV cell temperatures and enhanced temperature uniformity. • MHS with SRM increased output power and improved electrical efficiencies of HCPV cells. • Larger flow rate induce better thermal and electrical performance of HCPV cells with MHS with SR. Efficient cooling is critical to reduce cell temperatures of high concentration photovoltaic (HCPV) cells to avoid the output electrical performance degradation and lifetime reduction. In this study, we develop a novel type of microchannel heat sink (MHS) with serpentine reentrant microchannels (SRM) for efficient cooling of HCPV cells. They feature serpentine flow passages with Ω-shaped cross-sectional configurations, which contribute to promote fluid mixing and disrupt the normal development of thermal boundary layers. Thus they are able to provide excellent heat transfer characteristics and highly efficient cooling performance. By the comparison of a fin heat sink, both numerical and outdoor experimental studies were comprehensively conducted to explore the enhancement feasibility of thermal and electrical performance of HCPV cells. Results showed that the SRM reduced the cell temperatures and enhanced the temperature uniformity of HCPV cell module considerably, i.e., it presented cell temperatures of 25-31℃, much smaller than that of 45-63℃ of the fin heat sink. The temperature differences of HCPV cell modules were reduced to be less than 4.4℃. Besides, the output power increased by as high as 115%, and the electrical efficiency increased to 15–20% for the HCPV cell module with serpentine reentrant microchannels. Besides, the HCPV cell module with SRM was also found to induce smaller average cell temperatures and better electrical performance than a module with parallel reentrant microchannels (PRM). Moreover, the effects of flow rate and concentration ratio on the performance of HCPV cells with SRM were also assessed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A standalone diesel-fueled SOFC distributed power generation system is proposed. • With a steam/carbon ratio of 3.5, the proposed system shows an efficiency of 52.4%. • Higher steam/carbon ratio and higher SOFC temperature increase the efficiency. • Condensing the steam content in the raw syngas will improve the system efficiency. • S-based content negatively affects the system efficiency and needs to be removed. Solid oxide fuel cell (SOFC) recently emerges as a promising technology for distributed power generation with high energy efficiency. While H 2 production and delivery are still the hurdles, diesel can be accessed easily. Thus, it would be of great advantage to generate electricity through an SOFC-based power generation system fueled with diesel. In this work, a standalone diesel-fueled SOFC distributed power generation system combining a steam reformer, a water condenser, a desulfurizer, an SOFC, and a burner is proposed and analyzed thermodynamically. C 16 H 34 is used as a diesel surrogate fuel in the analysis. To realize independent operation of the system, all the heat required by the reformer is supplied by the combustion of the unreacted flue gas from SOFC. With a steam to carbon ratio of 3.5, a reformer temperature of 800 ℃, and an SOFC temperature of 800 ℃, the fuel utilization is determined to be 0.72, and the system presents an energy efficiency of 52.4%. The water condenser is of great importance to improve the system efficiency by eliminating fuel-dilution effect attributing to the existence of H 2 O, without which the energy efficiency decreases to 50.6%. Further, to add a desulfurization unit or to use pre-desulfurized fuel is of great importance as the existence of H 2 S will cause an immediate drop of the system efficiency of ∼ 5% and may lead to irreversible damage. A parametric study is performed and presented and the implications for future research focus are discussed. [ABSTRACT FROM AUTHOR]

• This paper proposes a filter in constructing the preconditioner for solving linear equation systems of the radiation diffusion problems. • This paper designs and investigates four kinds of strategies for filtering out the entries. • This paper conducts some numerical experiments to verify the effectiveness of the proposed method. • This paper studies the inuence of the parameter in the proposed method and provides a practical approach to choose a proper one for the radiation diffusion problem. The coefficient matrices of the linear equation systems arising from the radiation diffusion problems usually have orders of magnitude difference between their off-diagonal entries. While solving these linear equations with a preconditioned iterative method, the entries with small magnitudes may be insignificant to the preconditioner efficiency. In this paper, we use a filter to remove such small entries in the coefficient matrix while constructing the preconditioner. The proposed filter eliminates the small entries first according to a so-called weak dependence matrix, which relies on the conception of the strength of connections in algebraic multigrid. The preconditioner is then built based on the filtered matrix instead of the original one. Four strategies of filtering out entries are designed and investigated. Numerical results for various model-type problems and two real application problems, i.e., the multi-group radiation diffusion equations and the three temperature energy equations, are provided to show the effectiveness of the proposed method. In particular, this paper provides a practical approach to choose a proper parameter in the proposed method, which should help solve linear equation systems of radiation diffusion problems. [ABSTRACT FROM AUTHOR]

• 3D-printed reentrant microchannels structures (RMS) were developed by selective laser melting; • RMS reduced wall superheat for onset of nucleation boiling (ONB) considerably; • Heat transfer enhancement of 10% to 330% was achieved for RMS in subcooled boiling tests; • RMS increase active nucleation sites and provide more liquid replenishment for surface rewetting This study developed reentrant microchannels structures (RMS) by the Selective Laser Melting (SLM) technique for pool boiling enhancement. The 3D-printed reentrant microchannels structures were of parallel Ω-shaped reentrant channels with rough wall surfaces, which were built of bronze powder. Pool boiling tests of the RMS were conducted in deionized water in both saturated and subcooled boiling conditions with two liquid subcoolings of 15°C and 30°C. The pool boiling enhancement was explored by the comparison of a solid plain surface as benchmark. It was found that the reentrant microchannels structures reduced the wall superheat for onset of nucleation boiling (ONB) considerably, and generally present a 10% to 330% enhancement in boiling heat transfer coefficients over the plain surface in subcooled boiling conditions. The enhancement can be attributed to that the reentrant microchannels structures contributed to significant increase in active nucleation sites, enlarged surface area for heat exchange, and more liquid replenishment for surface rewetting. The boiling heat transfer coefficients of RMS generally exhibited a rapid decline at small heat fluxes region, then maintained to be more or less stable or increased slightly at moderate to high heat flux regions, and lastly decreased slightly at high heat flux region. The boiling heat transfer of RMS can be enhanced remarkably in the subcooled boiling tests. [ABSTRACT FROM AUTHOR]

Aim: The objective of the study reported here was to evaluate the therapeutic effects of hapten-enhanced chemoimmunotherapy in the treatment of advanced lung cancer by ultra-minimum incision personalized intratumoral chemoimmunotherapy (UMIPIC) and to analyze the effect of this immune booster., Materials and Methods: A total of 97 patients with advanced lung cancer were treated with UMIPIC or intratumoral chemotherapy (ITCT). UMIPIC was delivered intratumorally in combination with a proprietary therapeutic regimen composed of three components - an oxidant, a cytotoxic drug, and hapten. ITCT applied using the same procedures and regimen, only without hapten. All data from the two groups were reviewed and analyzed. A total of 55 patients were treated with UMIPIC and 42 with ITCT. Patient responses were assessed with computed tomography scan 4-6 weeks after treatment, and all of the patients were followed until their deaths., Results: Median overall survival was 11.23 months in the UMIPIC (test) group and 5.62 months in the ITCT (control) group ( P <0.01). The 6-month and 1-year survival rates of the UMIPIC and ITCT groups were 76.36% versus 45.23% ( P <0.01) and 45.45% versus 23.81% ( P <0.05), respectively. Two cycles of UMIPIC treatment (n=19) conferred a significant survival benefit compared with two cycles of ITCT (n=29); significant benefits in survival time were also found with UMIPIC (n=20) compared with ITCT (n=13) when both were utilized without adjuvant treatment., Conclusion: The hapten-enhanced clinical effect of UMIPIC conferred a superior survival time in patients with advanced lung cancer compared with ITCT. The addition of the hapten in UMIPIC demonstrates a significant advantage in terms of prolonged survival time., Competing Interests: Disclosure The authors declare no conflicts of interest in this work; the authors have no outside funding source.