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The origin of morphological innovation has been extensively studied within evolutionary developmental biology (evo‐devo). Recent studies have demonstrated that the developmental module for double‐layered epithelial outgrowths is conserved between the insect wings and branchiopod crustacean carapace, thereby introducing homology among these diverse structures. However, evo‐devo studies on the branchiopod crustacean carapace have been primarily limited to a single species, the water flea Daphnia magna, leaving the gene regulatory network governing carapace development not comprehensively understood. Furthermore, realizator genes downstream of the character identity mechanism (ChIM) for bilayered epithelial development remain inadequately described. In this study, we analyzed tissue‐specific transcriptional profiles in the developing longtail tadpole shrimp, Triops longicaudatus. We observed significant upregulation of papilin in the carapace‐bearing head, along with its expression in both the carapace and the trunk limb lobes. Based on these results, we hypothesize that differential expression of papilin is involved in the disproportional growth of Triops carapace. Our findings will contribute to elucidating the diversification of double‐layered epithelial outgrowths across distant arthropod lineages. Research highlights: First tissue‐specific transcriptomic approach on the Triops carapace development.Putative involvement of papilin in the carapace expansion of Triops head. [ABSTRACT FROM AUTHOR]

Over the past decade, the prevalence of mass outbreaks involving non-native insects has sparked concerns about their potential negative impact on human inhabited areas and local environments. Plecia longiforceps Duda, 1933 (Diptera, Bibionidae) was recently recognized as an invasive pest in South Korea, causing public nuisance through mass outbreaks in the Seoul Metropolitan Area during early summer. In this study, we present the first complete mitochondrial genome of Plecia longiforceps, generated from the PacBio HiFi long-read sequencing data. Notably, the length of the circular genome is found to be larger than any annotated reference sequences of mitochondrial genomes for the infraorder Bibionomorpha, which is attributable to an unusually long A+T rich control region. We conducted a phylogenetic analysis of Bibionomorpha, focusing specifically on the family Bibionidae, using nearly all available mitochondrial genome data to elucidate relationships among genera within Bibionidae. Our phylogeny of Bibionomorpha recovered a strong monophyly of the family Bibionidae and its three subfamilies: Bibioninae (Bibio + Dilophus), Hesperininae (Hesperinus + Penthetria), and Pleciinae (Plecia), corroborating the recently proposed taxonomic classification system of Bibionidae. Furthermore, we discuss evolutionary trends within Bibionidae based on our well-supported higher relationships of the superfamily Bibionoidea. [ABSTRACT FROM AUTHOR]

In this research, the thermodynamic analysis of the dimethyl ether (DME) autothermal reforming (ATR) in a membrane-packed catalyst bed was carried out for hydrogen production and purification. The purification was performed using semipermeable membrane made of Pd/Ag with a thickness of 50 μm and a length of 30 cm. A CFD model was developed to simulate the distribution of hydrogen concentration gradients spatially, and the chemical reaction mechanism of autothermal reforming of dimethyl ether to produce hydrogen was explored. The effects of several critical operating parameters (temperature, mass flow rate, and sweep gas ratio) were investigated in terms of DME conversion and hydrogen recovery. The purification process of hydrogen permeating through a semi-permeable membrane was optimized by changing the inlet mass flow rate of the permeate side purge steam. The simulation results show that the dimethyl ether is nearly completely converted at a temperature of 400℃, meanwhile increasing the inlet flow rate of the sweep steam (e.g., 10 times that of the reaction side) can effectively improve the hydrogen purification efficiency thereby reducing the residual hydrogen content in the syngas. [ABSTRACT FROM AUTHOR]

In this study, a thermodynamic analysis of the low temperature autothermal reforming (ATR) of dimethyl ether (DME) for hydrogen production was conducted. The Pd/Zn/γ-Al2O3 catalyst coated on the honeycomb cordierite ceramic was applied to catalyze the reaction, and the optimum activity temperature of this catalyst was demonstrated experimentally and through simulations to be 400 °C. Furthermore, an optimal model predictive control (MPC) strategy was designed to control the hydrogen production rate and the catalyst temperature. Experimental and simulation results indicated that the controller was automated and continuously reliable in the hydrogen production system. By establishing the state-space equations of the autothermal reformer, it can precisely control the feed rates of DME, high-purity air and deionized water. Ultimately, the hydrogen production rate can be precisely controlled when the demand curve changed from 0.09 to 0.23 mol/min, while the catalyst temperature was maintained at 400 °C, with a temporary fluctuation of 4 °C during variations of the hydrogen production rate. Therefore, the tracking performance of the hydrogen production and the anti-disturbance were satisfactory. [ABSTRACT FROM AUTHOR]

Plecia longiforceps Duda (Diptera: Bibionidae) is reported for the first time from Korea. P. longiforceps has been previously known from the East Asian subtropics, south of the 33rd parallel, including southeastern China, Taiwan, and the Ryukyu Islands of Japan. An integrative taxonomic approach based on morphological examination of male genitalia and molecular analysis of mitochondrial cytochrome c oxidase subunit I gene sequences confirms the species identification. The recent outbreak of P. longiforceps in the Seoul Metropolitan Area, Korea, documented herein represents the northernmost record of this species and suggests its possible range expansion into the temperate zone. Similar to the range expansion and outbreak history of Plecia nearctica Hardy (Diptera: Bibionidae) in North America around the Gulf of Mexico in the 1960–1970s, P. longiforceps may become a new invasive pest in temperate East Asia. Here, we evaluate range expansion and invasion potential of P. longiforceps through Ensemble species distribution modeling and show that a great portion of Northeast Asia and Japan will likely become habitable for P. longiforceps in the next 50 years. [ABSTRACT FROM AUTHOR]

A great deal of research effort has been dedicated for designing an efficient bifunctional metal‐free carbon catalyst for electrochemical water splitting, however, it remains challenging to introduce multiactive sites into a single catalyst. Herein, a series of bifunctional catalysts is designed that exploit intramolecular reorientation of nitrogen atom within the hollow nanoball from polyacrylonitrile on graphene through thermal treatment to achieve covalent doping. The as synthesized hollow carbon nanoballs on graphene (HCNB@G) catalysts have huge defective edges and microporous channels and contain a high density of electroactive graphitic‐N and pyridinic‐N as dual‐active sites. As a result, the optimized HCNB@G‐700 enhances electrocatalytic activities for both oxygen evolution and hydrogen evolution reactions (OER and HER) in 1.0 m KOH by generating 217 and 108 mV overpotential to gain a current density of 10 mA cm−2, respectively. This remarkable electrocatalytic activity mainly originates from the appropriate combination of suitable nitrogen active sites and edge defects with microchannels that not only facilitate the penetration of electrolyte but also improve the stability of the HCNB@G. In addition, the superior conductivity and high surface area of HCNB@G boost electrocatalytic activity by supporting efficient charge transport and enabling rapid mass diffusion with gas release, respectively. [ABSTRACT FROM AUTHOR]

Summary: Thermochemical methods, such as the sulfur‐iodine cycle and hybrid sulfur cycle, are more advantageous than conventional hydrogen production methods, such as fossil fuel reforming and water electrolysis, for large‐scale hydrogen production. Sulfuric acid decomposition is a highly endothermic reaction of the sulfur‐iodine cycle. To sustain this endothermic process using high‐temperature waste heat from solid oxide fuel cells (SOFCs), we propose an integrated thermochemical reactor combined with SOFC by taking a computational approach. First, a thermodynamic analysis was performed to evaluate the heat production of SOFC to sustain the thermochemical reaction in the combined reactor, resulting in a required waste heat of 0.565 kW from the SOFC that was obtained by consuming 0.0241 kg‧h−1 of H2 to process 1.0 kg‧h−1 of the H2SO4 mixture for the H2SO4 decomposer. For the SOFC inlet temperatures 923, 1023, and 1173 K, the corresponding SO3 conversions of the combined reactor were 72.1%, 77.3%, and 85.1%, respectively. A further increase of over 1200 K in the operating temperature led to a minor improvement in the SO3 conversion efficiency. In the SOFC section, the H2 mass fraction decreased from 67.9% to 10.8% in the anode channel, and 0.169 kW of electrical power was generated when the operating cell voltage and energy efficiency were 0.7 V and 53.71%, respectively. [ABSTRACT FROM AUTHOR]

Water management is one issue that must be surpassed to ensure high membrane proton conductivity and adequate reactant transport in the membrane-electrode assembly (MEA) simultaneously. A well-designed water management system is based on a comprehensive understanding of water transport in the inner part of the polymer electrolyte membrane (PEM) fuel cell. In this work, the water transport phenomena in the MEA PEM fuel cell are analyzed by using a mathematical model. The transport of diluted species interface is used to model the transport of water in the ionomer phase in the catalytic layer and the membrane domains. The molecular flux of water is defined using Nernst–Planck equations, including migration and Fickian diffusion using parameters obtained experimentally for diffusivity and mobility based on water drag for a fully humidified membrane. The proposed model 1D model includes anode gas channel, cathode gas channel, anode gas diffusion layer (GDL), cathode GDL, anode catalyst layer, cathode catalyst layer, and proton exchange membrane. Water activity, ionomer conductivity, and output voltage are predicted by changing the humidity on the anode side of the fuel cell. [ABSTRACT FROM AUTHOR]

Introducing abundant active sites and improving their activity are two critical considerations for designing metal-free nitrogenous electrocatalysts for the oxygen reduction reaction (ORR) in energy conversion devices such as metal–air batteries and fuel cells. In this study, we have developed nitrogenous carbon nanoballs with edge-abundant graphitic nitrogen (N) which were derived from polyacrylonitrile (PAN) on reduced graphene oxide (PANRGO). Upon carbonization, PAN promotes the generation of a carbon nanoball-like structure with defective edges and a hollow structure on graphene (PANRGO-700) without any template which substantially enhances the ORR kinetics by increasing the activity and accessibility of active sites. Consequently, the PANRGO-700 catalyst exhibits a high ORR catalytic activity compared to Pt/C by displaying a higher half-wave potential and kinetic current density of 0.864 V and 32.6 mA cm−2, respectively, in 0.1 M KOH. Further, its superiority as the cathode electrode was confirmed in a home-made Zn–air battery with producing a comparable power density of 116.6 mW cm−2. [ABSTRACT FROM AUTHOR]

This study aims to analyze effect of needle position inside nozzle on the internal and external flow characteristics. To visualize cavitating flow inside nozzle, the transparent acrylic nozzle was used. We tested five needle positions that simulated the needle movement of injector. The cross-section of test nozzle is rectangular with a very narrow width instead of circular shaped for a better visualization of cavitating flow. The inside of the nozzle was visualized by the shadowgraphic visualization using a high-speed camera and a metal-halide lamp. From the experiments, development of the cavitating flow according to the needle positions depends on the flow velocity and the cavitation number. The cavitation length, cavitation width, and spray angle are relatively symmetrically shown when the needle was at the center. However, they were asymmetrical when the needle position was biased. When the needle positions were in the same on the vertical line, the minimum cavitation length, minimum cavitation width, and minimum spray angle were larger when the upper level. The needle position affects the development timing and cavitation growth. When the needle position was located at the upper level, the hydraulic flip occurred at a higher injection pressure than the lower level. [ABSTRACT FROM AUTHOR]

This study aims to analyze effect of needle position inside nozzle on the internal and external flow characteristics. To visualize cavitating flow inside nozzle, the transparent acrylic nozzle was used. We tested five needle positions that simulated the needle movement of injector. The cross-section of test nozzle is rectangular with a very narrow width instead of circular shaped for a better visualization of cavitating flow. The inside of the nozzle was visualized by the shadowgraphic visualization using a high-speed camera and a metal-halide lamp. From the experiments, development of the cavitating flow according to the needle positions depends on the flow velocity and the cavitation number. The cavitation length, cavitation width, and spray angle are relatively symmetrically shown when the needle was at the center. However, they were asymmetrical when the needle position was biased. When the needle positions were in the same on the vertical line, the minimum cavitation length, minimum cavitation width, and minimum spray angle were larger when the upper level. The needle position affects the development timing and cavitation growth. When the needle position was located at the upper level, the hydraulic flip occurred at a higher injection pressure than the lower level. [ABSTRACT FROM AUTHOR]

Summary: The mass transport system in vanadium redox flow batteries (VRFBs) is very complex, which makes it difficult to predict the cycling performance and analyze the characteristics of VRFBs. In particular, ions and water move through the membrane by various transport mechanisms such as diffusion, convection, electro‐osmosis drag, and osmosis accompanied by side reactions. This complex transport system causes an imbalance in the electrolyte volume and concentration difference between the anolyte and catholyte tanks during charge/discharge cycling. As the performance of a VRFB is strongly affected by the electrolyte concentration, predicting the volume and concentration of the electrolyte is crucial to predict the performance of a VRFB and plan a rebalancing strategy for it. This study aims to accurately predict the cycling performance and efficiencies (coulomb, voltaic, and energy efficiency) of a VRFB by conducting a computational simulation that considers the electrolyte volume change, owing to the complex mass‐transport system in a VRFB, for the first time. The simulation result shows that the diffusion of water and electro‐osmosis of proton for an internal circuit have a dominant influence on the electrolyte volume change during the cycling process. It is observed that the electrolyte volume change is mainly caused by water diffusion in the initial cycles. Thereafter, it is found that osmosis predominantly influences the electrolyte volume change in a VRFB. The cycling performance and efficiency are calculated and validated with experimental data, which confirms the high fidelity of the model. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate effects of length-to-width (L/W) ratio on cavitation flow inside a transparent acrylic nozzle orifice, and its effects on spray angle. Three visualization nozzles with different geometries (L/W = 2.0, 2.67, and 4.0) are used, and the working fluid is water. In order to visualize the development process of cavitation, the injection pressure of the working fluid is changed, and a high-speed camera is used with a metal-halide lamp. From experiments and analysis, some important facts are determined. As the injection pressure increases, the cavitation length and thickness increase linearly until the hydraulic flip occurs. Although the cavitation width varies according to the orifice width, the maximum cavitation thickness relative to the orifice width is almost constant at approximately 25% ∼ 30%. When the nozzle shape ratio increases, the discharge coefficient tends to increase because of the decrease in friction area. When entering the hydraulic flip region, the discharge coefficient decreases due to the reduction of the exit section area. The spray angle is affected by the cavitation number, cavitation length, cavitation thickness, and Reynolds number. The higher the injection pressure, the higher the turbulence intensity, and the greater the instability of the fluid flow. [ABSTRACT FROM AUTHOR]

Summary Alkaline‐based organic redox flow batteries (AORFBs) attract significant interest because they can retain the advantages of vanadium redox flow batteries (VRFBs) while being low‐cost because expensive vanadium is replaced with easily synthesizable metal‐free organic compounds and earth‐abundant raw materials. A comprehensive experimental study on the performance of AORFBs using alloxazine 7/8‐carboxylic acid (ACA) and ferrocyanide was conducted to investigate the feasibility of these batteries as large‐scale energy storage systems. The operating conditions, such as the electrolyte concentration, flowrate, and temperature, were varied in this study. The results show that the present AORFB achieves an energy efficiency above 76% at 80 mA cm−2 at elevated temperature (55°C). Compared with those of VRFBs, AORFBs exhibit very good thermal stability and capacity retention. A large‐scale AORFB was constructed and tested to confirm the effectiveness of AORFBs. [ABSTRACT FROM AUTHOR]

Summary: Computational models are developed to allow for a deeper understanding of design factors that affect the lifetime of a vanadium redox flow battery (VRFB) stack, particularly related with the contact‐resistance issue of end cells in a large‐scale stack. A simplified microcontact‐resistance model and a physics‐based macrocontact‐resistance model are constructed to investigate the effect of contact resistance on the performance and longevity of VRFB stacks. A microcontact‐resistance model predicts significant heat accumulation in the current‐collector plate that can result in irreversible damage of plastic materials and an electrical‐voltage loss if the contact resistance is not properly engineered in the stack design. Furthermore, the physics‐based macrocontact‐resistance model investigates abrupt voltage and current distortion in the bipolar plate that is in imperfect contact with the current collector; this results in the local corrosion of the bipolar plate. To ensure a long lifetime of VRFBs, a stack design with minimal contact resistance (less than 0.1 Ω cm2) is required. The structural design of the endplate as well as the selection of a high‐stiffness material is critical to mitigate the bending issue and reduce contact resistance. [ABSTRACT FROM AUTHOR]

To reduce the internal resistance of battery cells or electrolyte leakage, stacked type battery packs are typically assembled and are tightly compressed by fixture structures such as endplates. Endplates must have enough rigidity to uniformly compress a battery stack, especially for large-formatted battery stacks. The present study proposes a computational approach to analyze and predict the bending deformation of endplates of stacked type battery packs. Computational result agrees well with the actual measurement of bending deformation in a flow battery stack. Analyzing the stress distribution of endplates, nine stiffener models are considered to minimize the bending deformation by reinforcing the endplates. It is found that the endplate with three vertical stiffeners is the most effective design. Additionally, response surface method (RSM) is conducted to find the optimal value of design parameters for the stiffeners. [ABSTRACT FROM AUTHOR]

Summary: Computational models are developed to allow for a deeper understanding of design factors that affect the lifetime of a vanadium redox flow battery (VRFB) stack, particularly related with the contact‐resistance issue of end cells in a large‐scale stack. A simplified microcontact‐resistance model and a physics‐based macrocontact‐resistance model are constructed to investigate the effect of contact resistance on the performance and longevity of VRFB stacks. A microcontact‐resistance model predicts significant heat accumulation in the current‐collector plate that can result in irreversible damage of plastic materials and an electrical‐voltage loss if the contact resistance is not properly engineered in the stack design. Furthermore, the physics‐based macrocontact‐resistance model investigates abrupt voltage and current distortion in the bipolar plate that is in imperfect contact with the current collector; this results in the local corrosion of the bipolar plate. To ensure a long lifetime of VRFBs, a stack design with minimal contact resistance (less than 0.1 Ω cm2) is required. The structural design of the endplate as well as the selection of a high‐stiffness material is critical to mitigate the bending issue and reduce contact resistance. [ABSTRACT FROM AUTHOR]

Summary: Instead of developing a new battery to meet required specifications of an automotive battery pack, different batteries can be combined to construct a hybrid battery module to simultaneously achieve both high power and high energy densities in a single system. To investigate the feasibility of battery hybridization concept, a circuit‐based hybrid battery model similar to physics‐based, blended‐electrode model is developed. Our simulation results confirm that the hybrid battery model shows good agreement with physics‐based model. Prototype hybrid battery modules consisting of two different lithium‐ion batteries are constructed according to various configurations. A computational model representing the constructed hybrid battery module is developed for model validation. Our experimental results show that the capacity and power of a battery module can be controlled by combining different batteries. The computational model of the hybrid battery shows good agreement with experimental results, confirming high fidelity of the proposed model. [ABSTRACT FROM AUTHOR]

Optimization of a catalytic combustor constructed using thin honeycomb ceramic substrates is reported herein. Honeycomb ceramic catalytic combustor is capable of providing heat to a dimethyl ether (DME) reformer, which is an essential requirement for an endothermic reforming process. The function of the proposed catalytic combustor is to maintain a uniform temperature distribution up to 500 °C. A fixed-bed flow reactor type combustor was set to operate under atmospheric pressure, and Pt/γ-Al2O3 catalyst was coated on the cordierite substrate (600 cell per square inch(cpsi)). Experimental variables considered in this study include the composition of multi-catalyst blocks, flow distributor, excess air ratio, space velocity, exit area ratio of the burner, and type of fuel. While performing the parametric study, the space velocity was selected in the range of 18000-27000 h-1 to ensure stable combustion (root mean square error (RMSE) < 10). For catalytic combustors employing C3H8 as fuel, optimized T-shaped and SiC foam distributors comprising three catalyst blocks with 50 % minimum area ratio of the combustor outlet were deemed as the best design combination in terms of superior combustion performance with temperature uniformity and no exhaust pollutants. For catalytic combustors fueled with DME, temperature variation on the surface of the combustor could be maintained within 17.6 °C of the reference temperature value. [ABSTRACT FROM AUTHOR]

A comparative study of LiFePO4 and LiCoO2 cells was conducted using two mathematical models to identify the physical characteristics of the two-phase electrode compared with the single-phase electrode under both charge and discharge conditions. First, the electrical conductivity of the LiFePO4 electrode was examined applying a two-dimensional electrical conduction model. The calculation results showed that the electrical conductivity of the LiFePO4 electrode could be improved significantly by coating the LiFePO4 particles with a conductive substance. Second, a modified physics-based cell model was applied to simulate the phase-change phenomena at the equilibrium boundary inside the LiFePO4 particles. The cell performance using LiFePO4 electrode was degraded significantly owing to the increase in ohmic loss and concentration loss caused by the low electrical conductivity and phase-change characteristics of LiFePO4 under high C-rate conditions. The present model was validated with experimental data and showed good agreement. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Electrode morphology has significant influence on the performance of lithium-ion batteries in that it controls electrical conductivity and electrode utilization by establishing electrical connectivity in the electrode. The present study investigates the effect of the electrode morphology on battery performance by combining two different mathematical models. First, a two-dimensional, direct numerical simulation (DNS) model is introduced, which stochastically generates electrode morphology and calculates electrical conduction and electrode utilization. Various simulations are conducted to evaluate the effect of the active particle coating, conductive agent loading, particle size, and electrode compression by using the DNS model. Second, data acquired from the DNS model are applied to the blended-electrode model to evaluate battery performance. Calculation result confirms that electrode morphologies have significant effects on both capacity and power of lithium-ion batteries. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]