Effect of coupling agent content on properties of composites made from polylactic acid and chrysanthemum waste

Chrysanthemum flower is among one of the highly sought after and widely planted flower crops, in particular for cultural and religious ceremonies. However, the chrysanthemum stem and stalk have little value and usually discard as by‐product waste from floristry. The objective of this research is to investigate the potential value of utilizing chrysanthemum stem and stalk as reinforcing fillers for thermoplastic composites. In this study, 2‐mm thick composite sheet containing predefined formulations of polylactic acid (PLA), chrysanthemum waste filler (CWF) ranging from 15 to 60 phr, and maleated polyethylene (MAPE) coupling agent up to 5 phr were prepared with the aid of Haake internal mixer and compression molding. The effect of MAPE loading on tensile, thermal, and morphological properties of PLA/CWF composites was investigated. The findings revealed that PLA/CWF composite attained improved tensile modulus compared to the neat PLA, and the tensile modulus increases with higher concentration of CWF. However, both tensile strength and elongation at break reduces with increase loading of CWF. Overall, PLA/CWF composites with MAPE shows better performance compared to those without MAPE, where an optimum strength of 21.8 MPa can be achieved with 60 phr CW and 3 phr MAPE. The measured tensile strength is comparable to alternatives natural fiber thermoplastic composites demonstrating its potential to be used in non‐structurally demanding application. J. VINYL ADDIT. TECHNOL., 26:10–16, 2020. © 2019 Society of Plastics Engineers     

基于秃鹰算法的PID参数自整定

基于PID参数整定是一种优化问题的本质上,尝试使用一种新的智能优化算法（秃鹰算法）进行PID参数整定。以常见的控制系统的开环传递函数,输入信号为单位阶跃来对比PSO算法和秃鹰算法的控制性能。实验结果表示,秃鹰算法进行PID参数具有较好的可行性,且性能优于PSO算法。     

Antibacterial activity of propolis against Staphylococcus aureus

In the present study, antimicrobial activity of the ethanolic extract of propolis (EEP), collected at different periods (June, August, and October-November) from various regions (Taipei, Mingchien, and Fanglia) in Taiwan, against Staphylococcus aureus was investigated. The effects of cell age, incubation temperature, and pH in response to EEP were also investigated. Depending on concentration, collecting area, and time, EEP exerted various degrees of antibacterial activity against S. aureus. The minimum inhibitory concentration of EEP tested ranged from <3.75 to 60 microg/ml, while the minimum bactericidal concentration ranged between 7.5 and 120 microg/ml against S. aureus. In general, a higher antibacterial activity was noted with EEP collected in August than other months. EEP of Mingchien-6 showed the most profound antibacterial activity among the EEP samples tested. The age of a bacterial culture affected its susceptibility to EEP. Cells in the late-exponential phase were most susceptible to EEP. Higher temperature (37 degrees C) and acidic pH enhanced the antibacterial activity of EEP.     

Preparation of ZnO-coated TiO2 electrodes using dip coating and their applications in dye-sensitized solar cells

This study investigates the applicability of a ZnO-coated TiO₂ working electrode in a dye-sensitized solar cell (DSSC). This working electrode was designed and fabricated by the following procedures: (1) two consecutive TiCl₄ treatments were performed when preparing the TiO₂ electrode, one prior to and the other following the spin printing of the TiO₂ colloid on a FTO-glass (Fluorine doped tin oxide, SnO₂:F) substrate; (2) a simple dip coating method was used to fabricate a ZnO-coated TiO₂ electrode by immersing a FTO-glass substrate with a TiO₂ film in a solution of zinc acetate dehydrate [Zn(CH₃COO)₂?2H₂O] and ethanol. This working electrode was then immersed in a solution of N-719 (Ruthenium) dye at a temperature of 70 °C for a preset duration. Finally, the DSSC was assembled, and the short-circuit photocurrent, the open-circuit photovoltage, and the power conversion efficiency of DSSC were measured using an I–V measurement system. The effects of the concentration of Zn(CH₃COO)₂?2H₂O, the duration of dipping, and the dye loading on the power conversion efficiency of a DSSC were also examined. Most importantly, this study shows that the power conversion efficiency of the DSSC with a ZnO-coated TiO₂ electrode (6.62%) substantially exceeds that of the conventional DSSC with a TiO₂ electrode (5.45%) due to the effects of a ZnO barrier and the TiCl₄ treatment.     

过程装备多媒体CAI应用软件的开发

以创作软件３ Ｄ Ｓｔｕｄｉｏ ４．０ 及 Ｍｉｃｒｏｓｏｆｔ Ｐｏｗ ｅｒｐｏｉｎｔ ９５ 与著作软件 Ａｕｔｈｏｒｗ ａｒｅ Ｐｒｏｆｅｓｓｉｏｎａｌ３．５ 为开发工具,开发了过程装备多媒体 Ｃ Ａ Ｉ应用软件,它涵盖了《化工设备设计》课程,并增加了生物流化床反应器等方面的内容,动画效果逼真、生动、形象地反映了单元操作设备零部件之间的结构关系。完善的交互设计,界面设计和导航设计极大地方便了用户的使用,尤其适合于课堂教学。     

Controllable Preparation of Al2O3‐MgO·Al2O3‐CaO·6Al2O3 (AMC) Composite with Improved Slag Penetration Resistance

Compact Al₂O₃‐MgO·Al₂O₃‐CaO·6Al₂O₃ (AMC) composite was obtained by melting technology using industrial alumina, light‐burned magnesia, and quick lime as raw materials based on the Al₂O₃‐MgO‐CaO ternary phase diagram. The results show that the phases of MgO·Al₂O₃ and Al₂O₃ are formed as the main framework with plate‐like CaO·6Al₂O₃ crystals mainly discontinuously embedded in MgO·Al₂O₃. The bulk density of AMC composite is up to 3.42 g/cm³, equivalent to 90.5% of the theoretical density. The synthesized compact AMC composite in the work also exhibits better slag penetration resistance than the castable based on tabular corundum due to the formation of liquid phase.     

Renal Protective Effects of Low Molecular Weight of Inonotus obliquus Polysaccharide (LIOP) on HFD/STZ-Induced Nephropathy in Mice

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease in diabetes mellitus. Oxidative stress, insulin resistance and pro-inflammatory cytokines have been shown to play an important role in pathogeneses of renal damage on type 2 diabetes mellitus (DM). Inonotus obliquus (IO) is a white rot fungus that belongs to the family Hymenochaetaceae; it has been used as an edible mushroom and exhibits many biological activities including anti-tumor, anti-oxidant, anti-inflammatory and anti-hyperglycemic properties. Especially the water-soluble Inonotus obliquus polysaccharides (IOPs) have been previously reported to significantly inhibit LPS-induced inflammatory cytokines in mice and protect from streptozotocin (STZ)-induced diabetic rats. In order to identify the nephroprotective effects of low molecular weight of IOP fraction (LIOP), from the fruiting bodies of Inonotus obliquus, high-fat diet (HFD) plus STZ-induced type 2-like diabetic nephropathy C57BL/6 mice were investigated in this study. Our data showed that eight weeks of administration of 10–100 kDa, LIOP (300 mg/kg) had progressively increased their sensitivity to glucose (less insulin tolerance), reduced triglyceride levels, elevated the HDL/LDL ratio and decreased urinary albumin/creatinine ratio(ACR) compared to the control group. By pathological and immunohistochemical examinations, it was indicated that LIOP can restore the integrity of the glomerular capsules and increase the numbers of glomerular mesangial cells, associated with decreased expression of TGF-β on renal cortex in mice. Consistently, three days of LIOP (100 μg/mL) incubation also provided protection against STZ + AGEs-induced glucotoxicity in renal tubular cells (LLC-PK1), while the levels of NF-κB and TGF-β expression significantly decreased in a dose-dependent manner. Our findings demonstrate that LIOP treatment could ameliorate glucolipotoxicity-induced renal fibrosis, possibly partly via the inhibition of NF-κB/TGF-β1 signaling pathway in diabetic nephropathy mice.     

Effects of the organometallic coupling agents on adhesion of the carbon fiber–BMI composites

In order to increase the chemical bonding force between fiber and resin, several kinds of organometallic coupling agent (such as titanate, zirconate, and zircoaluminate) were chosen and added in the BMI resin formulation, which possess the same solvent system with those coupling agents. The DSC analysis technique was used to find the best curing condition, and TGA was used to investigate the thermal stability property of the best curing condition. For the purpose of analyzing the bonding structure, ESCA surface element analysis techniques was applied in this study. Beside that, the mechanical properties of tensile, flexural, and short-beam shear strengths were measured for the effect of adding coupling agents, and the SEM of fracture surfaces were taken to study the fractural analysis. The results showed that composites with the application of organometallic coupling agents of [RO–Ti(OX–R′NH₂)₃] structure in the treatment of BMI resin were highly thermal stable. Also, it was shown that the mechanical strengths of composites fabricated by pretreatment of the carbon fibers with coupling agents were higher than those fabricated by adding coupling agents in resins, but there was no obvious improvement of mechanical properties with higher concentration of coupling agents. However, the SEM showed that the adhesion between fiber and resin can actually be improved by adding proper amount of coupling agents in the BMI resin formulation.     

Development of 1D model for the analysis of heat transport in cylindrical micro combustors

A 1D flame model was developed to analyze the heat transport occurring in the cylindrical micro combustors. The one-step global reaction mechanisms were employed for three fuel–air mixtures (H₂–air, CH₄–air and C₃H₈–air) to account for the difference of fuel property in terms of the kinetics. The effects of various parameters such as the combustor size, fuel property, fuel–air equivalence ratio and unburned mixture temperature on the heat loss ratio (defined as Q_l/Q_in) and the heat recirculation ratio (defined as Q_recir/Q_l) were investigated. The results indicated that these parameters have significant effects on the two ratios, and therefore should be carefully managed in order to achieve efficient and stable combustion. After comparing the results of different fuel–air mixtures, it is concluded that hydrogen is superior to methane and propane as the fuel for micro combustion engines owing to its higher flame temperature and thinner flame thickness, which favors the reduction of heat loss from the flame zone.