Experimental and Numerical Investigation of a Novel Spiral Micromixer with Sinusoidal Channel Walls

A novel spiral micromixer with sinusoidal channel walls was designed to enhance the mixing index in the low to intermediate Reynolds number range (1 < Re < 100). To analyze the fluid flow, a set of numerical simulations were performed using the finite-difference method. The microchip was fabricated from polydimethylsiloxane, employing the soft-lithography technique. The degree of mixing was increased by 99.11 % when using the proposed micromixer, compared to 59.44 % for a simple spiral micromixer. The introduced microchannel drastically reduced the mixing length, increasing the mixing index of a 0.5-loop spiral-sinusoidal microchannel compared to that of the simple spiral microchannel with 1.5 loops. The mixing index of the 3-loop mixer was higher than that of the microchannel with 1.5 loops, and its pressure drop was increased.     

Ternary type BaY2ZnO5: Eu3+ deep-red phosphor for possible latent fingerprint,security ink and WLED applications

Pc-WLEDs are considered to play a spectacular role in future generation light sources in view of their outstanding energy efficiency. In this regard, Eu³⁺ activated BaY₂ZnO₅ phosphor was prepared and investigated by XRD, PL and SEM analyses. Rietveld refinement analysis was carried out to confirm the structure of the synthesized phosphor. The prepared phosphor shows an intense red emission around 627 nm under excitation by near UV light. The ⁵D₀-⁷F₂ transition intensity of the prepared phosphor is three times higher compared to the commercial (Y,Gd)BO₃:Eu³⁺ red phosphor. The CIE colour coordinates of BaY₂ZnO₅:Eu³⁺ (9mol%) phosphor corresponds to be (0.6169, 0.3742) and it has a high 97.9 % colour purity. The obtained results reveal the utility of BaY₂ZnO₅:Eu³⁺ phosphor as an efficient red component in WLEDs, anti-counterfeiting and fingerprint detection applications.     

具有保护肠上皮细胞HT-29免受大肠杆菌和H2O2损伤潜力的植物乳杆菌的筛选

益生菌可在肠道定植从而发挥抗炎或抗氧化活性，有利于宿主肠道健康。本实验研究了从新疆传统发酵乳制品中分离得到的8?株植物乳杆菌对大肠杆菌侵袭和过氧化氢刺激肠上皮细胞HT-29的保护作用。结果表明：在8?株植物乳杆菌中，植物乳杆菌35具有最高的黏附能力。植物乳杆菌35可通过取代、竞争、排阻的方式抑制大肠杆菌对HT-29细胞的黏附，抑制率分别为42.60%、59.17%、60.19%。植物乳杆菌35及其多糖可抑制大肠杆菌刺激HT-29细胞产生白细胞介素-8；同时保护HT-29细胞免受过氧化氢的损伤，增加超氧化物歧化酶、谷胱甘肽过氧化物酶活力水平并降低丙二醛含量。结论：植物乳杆菌35及其粗胞外多糖具有抑制大肠杆菌O157诱导的炎症性肠病的潜力。     

Multi-objective planning and optimization of microgrid lithium iron phosphate battery energy storage system consider power supply status and CCER transactions

Lithium iron phosphate battery (LIPB) is the key equipment of battery energy storage system (BESS), which plays a major role in promoting the economic and stable operation of microgrid. Based on the advancement of LIPB technology and efficient consumption of renewable energy, two power supply planning strategies and the china certified emission reduction (CCER) model are proposed respectively. Based on it, the multi-objective planning optimization model with economic benefits, environmental benefits and power supply stability as the objective function is established for the first time, and the Newton Weighted Sum Frisch method (NWSFA) solution model is adopted. In the planning process, rain flow counting method is used to research the life of BESS, which improves the accuracy of energy storage annual cost calculation. A park in northern China is taken as a case study to demonstrate the application of this model. The simulation results show that the annual economic operating cost of BESS is decreased by 18.81%, the energy supply reliability is increased by 0.15%, and the optimal electricity price adjustment ratio of the system is 15%.     

Statistical optimization of operating parameters of microbial electrolysis cell treating dairy industry wastewater using quadratic model to enhance energy generation

The performance of Microbial electrolysis cell (MEC) is affected by several operating conditions. Therefore, in the present study, an optimization study was done to determine the working efficiency of MEC in terms of COD (chemical oxygen demand) removal, hydrogen and current generation. Optimization was carried out using a quadratic mathematical model of response surface methodology (RSM). Thirteen sets of experimental runs were performed to optimize the applied voltage and hydraulic retention time (HRT) of single chambered batch fed MEC operated with dairy industry wastewater. The operating conditions (i.e) an applied voltage of 0.8 V and HRT of 2 days that showed a maximum COD removal response was chosen for further studies. The MEC operated at optimized condition (HRT- 2 days and applied voltage- 0.8 V) showed a COD removal efficiency of 95 ± 2%, hydrogen generation of 32 ± 5 mL/L/d, Power density of 152 mW/cm² and current generation of 19 mA. The results of the study implied that RSM, with its high degree of accuracy can be a reliable tool for optimizing the process of wastewater treatment. Also, dairy industry wastewater can be considered to be a potential source to generate hydrogen and energy through MEC at short HRT.     

四氢姜黄素经PI3K/Akt信号通路对人血小板活化和聚集的调控作用

目的：探讨姜黄素的主要肠道代谢物四氢姜黄素（tetrahydrocurcumin，THC）对血小板活化和聚集的影响及其可能的分子机制。方法：在体外实验中，用不同浓度的THC（0、0.5、1、10 μmol/L）提前与健康人纯化血小板共同孵育40 min，然后加入凝血酶激活血小板2 min，用流式细胞术测定血小板表面CD62P和CD63的表达量，用酶联免疫吸附法测定血小板释放血小板因子-4（platelet factor-4，PF4）和趋化因子配体-5（chemokine ligand 5，CCL5）水平，用血小板聚集仪检测血小板释放ATP水平和血小板最大聚集率，用Western blot蛋白免疫印迹法检测血小板磷酸肌醇-3-激酶（phosphoinositide 3-kinase，PI3K）和Akt蛋白的磷酸化水平。结果：与模型组（血小板悬液中加入0.05%二甲基亚砜）相比，THC能抑制凝血酶诱导的血小板表面CD62P和CD63的表达，抑制PF4、CCL5和ATP的释放，降低血小板最大聚集率，下调PI3K和Akt蛋白的磷酸化水平，且呈浓度依赖效应，其中10 μmol/L的浓度下作用效果显著（P＜0.01、P＜0.001）。PI3K的特异性激动剂740 Y-P可部分逆转THC对PF4和CCL5释放和血小板聚集的抑制作用（P＜0.05、P＜0.01）。结论：THC具有显著抑制血小板活化和聚集的作用，其机制可能是THC可下调PI3K/Akt介导的信号通路。     

Numerical modeling of hydrogen catalytic reactions over a circular bluff body

This paper was intended to delineate numerical research for hydrogen catalytic combustion over a circular cylinder. The wire/rod-type catalytic reactor is a simple geometry reactor with an economical design with less pressure loss. For the single rod in the reaction channel, the flow characteristic and the difference of conversion efficiency between non-gas-phase reaction and gas-phase reaction have been delineated in the present study. The flow field and the chemical reactions were numerically modeled using 2D Large Eddy Simulation combined with the gas-phase and surface reaction mechanisms. The results show that the current numerical simulation has been validated to precisely predict the vortex shedding and its frequency in the cold flows. Despite the variation trends being dominated by the upstream flow, the vortex shedding phenomena were affected by the flue gas generated from the rod surface. It can be seen from the linear relationship between the vortex shedding frequency of reacting flow and Reynolds Number. It is noted that the vortex shedding vanished if the gas-phase reaction was ignited in the reaction channel. In addition, the geometric modified conversion efficiency was proposed to delineate an indicator that could be potential for the optimization of rod-type catalytic reactor. In summary, the fundamental study of a rod in a 2D flow channel can provide information for optimizing the catalytic design or the rod array arrangement in the reactor. Moreover, the rod can also be a partial catalytic flame holder to ignite and stabilize the gas-phase reaction. The obtained results could be the potential for practical applications of rod-type catalytic combustion, catalytic gas turbine, hydrogen generation, partially catalytic reaction flame holder, and other catalytic reactions that can be appreciated.     

Influence of mesoporous phosphotungstic acid on the physicochemical properties and performance of sulfonated poly ether ether ketone in proton exchange membrane fuel cell

This study demonstrates the successful development of hybrid mesoporous siliceous phosphotungstic acid (mPTA-Si) and sulfonated poly ether ether ketone (SPEEK) as a proton exchange membrane with a high performance in hydrogen proton exchange membrane fuel cells (PEMFC). SPEEK acts as a polymeric membrane matrix and mPTA-Si acts as the mechanical reinforcer and proton conducting enhancer. Interestingly, incorporating mPTA-Si did not affect the morphological aspect of SPEEK as dense membrane upon loading the amount of mPTA-Si up to 2.5 wt%. The water uptake reduced to 14% from 21.5% when mPTA-Si content increases from 0.5 to 2.5 wt% respectively. Meanwhile, the proton conductivity increased to 0.01 Scm^?1 with 1.0 wt% mPTA-Si and maximum power density of 180.87 mWcm^?2 which is 200% improvement as compared to pristine SPEEK membrane. The systematic study of hybrid SP-mPTA-Si membrane proved a substantial enhancement in the performance together with further improvement on physicochemical properties of parent SPEEK membrane desirable for the PEMFC application.     

Microscopic high-speed video observation of oxygen bubble generation behavior and effects of anode electrode shape on OER performance in alkaline water electrolysis

An important difficulty associated with alkaline water electrolysis is the rise in anode overpotential attributable to bubble coverage of the electrode surface. For this study, a system with a high-speed video camera was developed, achieving in-situ observation of bubble generation on an electrode surface, monitoring an area of 1.02 mm² at 6000 frames per second. The relation between polarization curve (current density up to 3.0 A cm^?2) and oxygen bubble generation behavior on nickel electrodes having cylindrical wires and rectangular wires of different sizes (100–300 μm) was clarified. The generated bubbles slide upward, contacting the electrode surface and detaching at the top edge. Observations indicate that small electrodes have short bubble residence time and thin bubble covering layer on the electrode. As a result, the small electrode diameter contributes to smaller overpotential at high current density.     

Hydrogen-rich gas generation via the exhaust gas-fuel reformer for the marine LNG engine

Reformed exhaust gas recirculation technology has attracted great attention in internal combustion engines. A platform of an exhaust gas-fuel reformer connected with the marine LNG engine was set up for generating on-board hydrogen. Based on the platform, effects of the methane to oxygen ratio (M/O) and reformed exhaust gas ratio (R_EG) from the reformer and excess air ratio (λ) from the engine on the components, hydrogen yield, thermal efficiency and reforming process of the reformer were experimentally investigated. Results shown that hydrogen-rich gases (reformate) can be generated by reforming the mixture of engine exhaust gas (about 400 °C) and methane supplied via the reformer with Ni/Al₂O₃ catalyst, and the hydrogen concentration of reformate was between 6.2% and 12.6% by volume. The methane supplied rate and λ affected the components and temperature of the reactant in the reformer, while R_EG changed the gas hour space velocity during the exhaust gas-fuel reforming processes, resulting in the difference in the components of the reformate and thermal efficiency. At the present experimental condition, the highest H₂ concentration reformate was generated under the M/O of 2.0, λ of 1.55 and R_EG of 6%.