高压加气混凝土/CFRP夹芯板的低速撞击响应

高压加气混凝土(AAC)-CFRP复合结构已证明可作为轻型结构材料用于连梁、过梁、墙或柱子。除了必须具有足够的受弯能力,AAC/CFRP复合结构也需要具有抵抗局部破坏力的性能。在使用过程中,这些结构可能会承受类似爆炸、或龙卷风、台风、暴风雪的局部撞击、冲击。为评估AAC/CFRP夹芯板结构抗低速冲击的响应能力,通过一个能量守恒模型得出的预测能量吸收值与试验结果进行对比。在相对低速下,AAC/CFRP可以承受相对低速重物的冲击,比如物体/工具落在梁上或对柱子的低速撞击。     

Adsorption and photocatalytic decolorization of a synthetic dye erythrosine on anatase TiO2 and ZnO surfaces

The UV radiation assisted photocatalytic decolorization/degradation kinetics of an anionic dye erythrosine (ER), has been studied over TiO2 and ZnO surfaces. Since adsorption is the prerequisite condition for decolorization/degradation of dye molecules in presence of heterogeneous catalysis, the Langmuir and Freundlich isotherms were examined to verify the adsorption intensity. Standard adsorption free energy measurement implies that the adsorption of ER on both TiO2 and ZnO surfaces is spontaneous endothermic process. The effect of catalyst loading (TiO2/ZnO) revealed the fact that the maximum decolorization rate is obtained under an optimized catalyst loading condition. The decolorization efficiency was also investigated over the pH range of 5.0-10.0 indicating that increasing pH enhances decolorization efficiency. The influence of H2O2 on decolorization efficiency was found noticeable since it is a hydroxyl radical provider. The kinetic study of this degradation indicates that under the experimental condition, the decolorization mechanism follows zero order kinetics on the basis of Langmuir-Hinshelwood (L-H) heterogeneous reaction mechanism.     

A rheological behavior of various polyvinylidene difluoride binders for high capacity LiNi0.6Mn0.2Co0.2O2

Various polyvinylidene difluorides (PVDF) as polymeric binding agent in lithium‐ion battery were rheologically evaluated on high capacity and excess lithium‐LiNi_0.6Mn_0.2Co_0.2O₂ (Ni‐rich NMC). We found that the suspension polymerized PVDF binder is more stable upon gelation for long duration while other high molecular weight PVDF binders (MW > 900,000) show irreversible rheological transformation that can dramatically compromise the coating step during lithium‐ion battery electrode slurry preparation. POLYM. ENG. SCI., 56:760–764, 2016. © 2016 Society of Plastics Engineers     

From “Strong” to “Much Stronger”: Utilization of Green Tea Extract Dispersant for SWCNT‐Reinforced Polymer Composites

PVA is reinforced with SWCNTs using green tea extract as a dispersant to achieve good dispersion of the SWCNTs in an organic solvent and finally high‐performance composite fibers. A combination of green tea extract/DMSO/SWCNT/PVA is found to disperse larger aggregates of SWCNTs to individual or thin bundles of a few nanotubes. Incorporation of 0.5 wt% SWCNTs into PVA fibers yields a tensile strength of 2.42 GPa, a Young's modulus of 46 GPa, toughness of 105 J · g^?1 at a failure strain of 11%, and a loop strength of 245 MPa, much higher than the values of commercial PVA fibers. The incorporation of highly dispersed SWCNTs suppresses the fibrillation tendency of the PVA fibers. The applied load is effectively transferred from the matrix to the SWCNTs.

     

Analysis of pork adulteration in commercial meatballs targeting porcine-specific mitochondrial cytochrome b gene by TaqMan probe real-time polymerase chain reaction

A test for assessing pork adulteration in meatballs, using TaqMan probe real-time polymerase chain reaction, was developed. The assay combined porcine-specific primers and TaqMan probe for the detection of a 109 bp fragment of porcine cytochrome b gene. Specificity test with 10 ng DNA of eleven different species yielded a threshold cycle (Ct) of 15.5 ± 0.20 for the pork and negative results for the others. Analysis of beef meatballs with spiked pork showed the assay can determine 100-0.01% contaminated pork with 102% PCR efficiency, high linear regression (r(2) = 0.994) and ≤ 6% relative errors. Residuals analysis revealed a high precision in all determinations. Random analysis of commercial meatballs from pork, beef, chicken, mutton and goat, yielded a Ct between 15.89 ± 0.16 and 16.37 ± 0.22 from pork meatballs and negative results from the others, showing the suitability of the assay to determine pork in commercial meatballs with a high accuracy and precision.     

Comparative Bio-Active Compounds Determination and In Vitro Antioxidant Properties of Newly Developed Soy Mixed Wheat Flour and Traditional Wheat Flour

The aims of this study were quantitative determination of the bio-active compounds and to evaluate the in vitro antioxidant activities of methanolic extract of soy mixed wheat flour and traditional wheat flour. Soy mixed wheat flour was developed by combination of processed soy flour and wheat flour. Total phenolics, flavonoids, tannin, and proanthocyanidin contents of the crude methanolic extract were determined by ultraviolet-visible spectrophotometer. Further individual bio-active compounds were determined by high-performance liquid chromatography-diode array detector and showed (+)-catechin, vanillic acid, caffeic acid, (–)-epicatechin, p-coumaric acid, rutin hydrate, and ellagic acid in soy mixed wheat flour but only rutin in traditional wheat flour. The soy mixed product showed significantly higher concentration of bio-active compounds than traditional wheat flour. Antioxidative activities were measured through different in vitro models: phosphomolybdenum blue method, FeCl₃ reducing power, ABTS scavenging activity, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity, N,N-dimethyl-1,4-diaminobenzene free radical scavenging activity, reducing power, metal chelating power and super oxide scavenging ability. All results of in vitro antioxidant models revealed that the soy product showed significantly higher antioxidant activities than traditional wheat flour. These results suggested that soy mixed wheat flour can play the greater roles than the traditional wheat flour for different physiological activities in human body due to the presence of greater amount of bio-active compounds and can be considered as a potential antioxidant containing flour for human consumption than the traditional wheat flour.     

Lie Group Analysis and Numerical Solutions for Magnetoconvective Slip Flow along a Moving Chemically Reacting Radiating Plate in Porous Media with Variable Mass Diffusivity

A numerical investigation of magnetoconvective boundary layer slip flow along a nonisothermal continuously moving permeable nonlinear radiating plate in Darcian porous media is reported. The concentration dependent mass diffusivity, viscous dissipation, Joule heating, and chemical reaction are taken into account. A Lie group of transformation is applied to the governing transport equations and boundary condition to find the corresponding similarity equations. Furthermore, the similarity equations with the relevant boundary conditions are solved numerically using the Runge‐Kutta‐Fehlberg fourth‐fifth order numerical method. Numerical results for the dimensionless velocity, temperature, and concentration distributions as well as friction factor, local Nusselt, and local Sherwood numbers are discussed for various controlling parameters. It is found that that the dimensionless concentration increases whilst the rate of mass transfer decreases with the mass diffusivity parameter. An excellent correlation is found between the present results and published results. The study finds applications in the polymer industry and metallurgy.     

Structural Characterization of Composite Structural Insulated Panels for Exterior Wall Applications

Structural sandwich composite panels are extensively used for modular panelized construction. This paper includes the structural characterization of the innovative composite structural insulated panels (CSIPs) developed for the exterior walls of a modularized structure. The facesheets of the CSIPs consist of E-glass fibers impregnated with polypropylene matrix, while the core consists of expanded polystyrene foam. The overall panel dimensions including the thickness of the facesheets and the core were obtained using sandwich composite design theories. Uniaxial compressive loading and high velocity impact (HVI) loading are the most important loading criteria for an exterior wall of a structure. The proposed CSIPs were tested for a compressive load of 13.13 kN/m (900 plf) in this study. The deflection at this load was ～ 3?mm which was within deflection limits of span/150 as prescribed in ACI 318-05 building design code. The proposed CSIP wall panels were also tested under HVI for the loads prescribed by Federal Emergency Management Agency for design of emergency shelters in hurricane prone areas. Based on the HVI testing, CSIPs were able to stop a blunt object projectile traveling at 135 m/s proving its suitability against HVI type of loading.     

Biallelic Variants in EPHA2 Identified in Three Large Inbred Families with Early-Onset Cataract

Hereditary congenital cataract (HCC) is clinically and genetically heterogeneous. We investigated HCC that segregates in three inbred families (LUCC03, LUCC16, and LUCC24). Ophthalmological examinations revealed cataracts with variability related to the age of onset segregating in a recessive manner in these families. Exome sequencing of probands identified a novel homozygous c.2710delG;p.(Val904Cysfs*36) EPHA2 variant in LUCC03 and a known homozygous c.2353G>A;p.(Ala785Thr) EPHA2 variant in the other two recessive families. EPHA2 encodes a transmembrane tyrosine kinase receptor, which is primarily involved in membrane-transport, cell-cell adhesion, and repulsion signaling processes. Computational structural modeling predicts that substitution of a threonine for an alanine p.(Ala785Thr) results in the formation of three new hydrogen bonds with the neighboring residues, which causes misfolding of EPHA2 in both scenarios. Insights from our study will facilitate counseling regarding the molecular and phenotypic landscape of EPHA2-related HCC.     

Changes in the wettability of polymer electrolyte fuel cells components during cationic contamination and mitigation

Foreign cations are shown to cause mass transport losses, in particular due to wettability changes in the micro-porous layers (MPL) and the carbon paper substrate, and have a major impact on the durability and the performance of polymer electrolyte fuel cells. We studied the effects of cationic impurities on fuel cell system performance, especially on the water management by employing in-situ and ex-situ contamination methods. Changes in the wettability of the carbon paper surface following the in-situ contamination injection were quantified using the Wilhelmy plate method. The CaSO₄ precipitation on the macro-pores of the carbon paper substrate after the contamination injection causes a higher wettability leading to increased flooding of the carbon paper substrate and consequent mass transport losses. An ex-situ cleaning with an acid solution is shown to be very effective in removing the salt deposits of the carbon paper substrate. During the mitigation, the highly hydrophobic MPL acts as a barrier to the transport of the recovery solution into the membrane-electrode assembly (MEA), therefore isopropanol (IPA) was added to both the contaminant solution and the recovery solution to increase the wettability of the MPL. Wetting force measurements confirm that the added IPA can alter the wettability of the MPL and can render it fully hydrophilic, enabling the transport of the recovery solution into the MEA.