Effects of direct current magnetic field treatment time on the properties of pork myofibrillar protein

This study investigated the effects of direct current magnetic field (DC-MF) treatment time (1, 3, 5, 8 h) on properties of porcine myofibrillar protein (MP). Gel water-holding capacity increased from 83.40% to 87.20% when DC-MF-treatment time changed from 1-h to 8-h. The 3-h treatment time of DC-MF was found to promote MP unfolding, rearrangement and aggregation, leading to the loss of total sulfhydryl, the increase of reactive sulfhydryl, surface hydrophobicity, turbidity as well as the formation of MP clusters and the greater degree of crosslinking as compared with 0-h treatment, thus a firmer and more ordered MP gel network for trapping more water. However, excessive DC-MF treatment (8-h) weakened DC-MF effect on MP aggregation as well as gel network and texture. This study has shed light on the effects of DC-MF treatment time on MP properties and provides useful information for the application of DC-MF in the food industry.     

土钉墙施工工艺和常见问题的处理

为确保开挖过程中基坑和岩土(质)边坡稳定性,提升施工安全水平,施工单位需合理地应用土钉墙施工工艺,以实现以上施工目标.主要分析了土钉墙的结构,研究了土钉墙施工流程及要求,探究了土钉墙施工中的常见问题并针对问题提出了处理对策.     

Preparation and co-dispersion of TiO2-Y2O3 suspensions through the study of their rheological and electrokinetic properties

The development of Generation IV sodium-cooled fast reactors (SFR) is currently studied by several countries, France in particular. To manufacture the UO₂-PuO₂ fuels for these new types of reactors, new innovative wet colloidal processing routes are investigated. Among these wet colloidal processes, some involve at first the preparation of high solid content water-based suspensions. This key step needs to be investigated in order to obtain highly and easily processable suspensions, featuring optimal viscosity and dispersion state. The structures and properties for all intermediate and final products involved in such ceramic manufacturing processes are heavily affected by these suspension characteristics. Therefore, they are critical to ensure a compliant final product (i.e. fuel pellets) with the required density, homogeneity, mechanical strength and absence of defects. In this scope, preparation process of such suspensions was developed by the use of UO₂ and PuO₂ surrogating (i.e. mimicking) powders, TiO₂ and Y₂O₃ respectively.     

Analytical Solutions to Predict Impact Behaviour of Stringer Stiffened Composite Aircraft Panels

Applied Composite Materials - This paper aims to develop an analytical method to predict the low-velocity impact response of simply supported stringer stiffened panels. Since the combination of...     

Detecting Spin Heat Accumulation by Sign Reversion of Thermopower in a Quantum Dot Side-Coupled to Majorana Bound States

We propose a scheme to detect the spin heat accumulation (SHA), an effective spin-dependent electron temperature, via sign reversion of thermopower induced by the Majorana bound states (MBSs) coupled to a quantum dot (QD). The SHA is generated in either a nonmagnetic material or a ferromagnet serving as an electrode connected to the QD and leads the spin-up and spin-down thermopowers to change signs at different temperatures with the help of QD-MBSs coupling. The existence of the SHA then can be detected by the variation of the spin-polarized or even charge thermopower with respect to the magnitude of the SHA. Our numerical results show that the transition temperature of the thermopower is sensitive to QD-MBSs coupling strength, hybridization between the MBSs, and the ferromagnetism on the leads. Around the transition temperature, either 100% spin-polarized or pure spin thermopower can be generated by the combined effects of SHA and MBSs. We also find that the intradot Coulomb interaction does not change the qualitative results of the present scheme.

     

Effect of heat treatment on corrosion of laser-textured aluminum alloy surfaces

The kinetics of electrochemical corrosion of aluminum alloy (AlMg6) surfaces with different wettability was analyzed. The surfaces were processed by three different methods, in particular, polishing, laser texturing, the combination of laser texturing and low-temperature heating. After laser processing, the dimple-like texture was formed on the surface, and the wettability significantly enhanced. Low-temperature heating of laser-textured AlMg6 alloy surfaces led to the wettability inversion from strongly hydrophilicity to superhydrophobicity. Microscopic and profilometric methods were used to estimate the surface degradation due to corrosion when aggressive solution droplets (a mixture of NaCl and hydrogen peroxide aqueous solutions) evaporated. The potentiodynamic polarization measurements of AlMg6 alloy surfaces were conducted. The typical modes of corrosion and evaporation of aggressive solution droplets were detected. The kinetics of corrosion was estimated by the behavior of the corrosion area evolution. In addition, when immersing laser-textured sample with strongly hydrophilic properties into aggressive solution, the higher corrosion rate was found in the liquid meniscus region (aggressive mixture / alloy / air interface) compared to the textured site immersed in the mixture. This was explained by convection increasing the rate of reaction products removal and promoting a stronger deviation from the equilibrium state in the aggressive mixture. Experimental results of the potentiodynamic polarization measurements revealed that laser-textured samples exhibit enhanced corrosion protective properties compared to polished samples.

Graphical abstract

     

Influence of Yag Concentration and Pressing Time on Wear of Si3N4 Based Ceramics

Strength of Materials - Abrasive wear resistance of Si3N4 strongly depends on its microstructure, in particular, grain morphology. In this work, the effects of β-content, β-Si3N4 grain...     

The effect of curvature on chondrocytes migration and bone mesenchymal stem cells differentiation

Numerous cells grow in columnar tissues and organs with different curvatures and curvature gradients. Therefore, it is necessary to study the effect of curvature on cell behavior to control and promote cell development. Herein, we prepared polydimethylsiloxane (PDMS) with different micro-nano patterns using ultraviolet soft lithography. Hydrophilic polydopamine (PDA) was modified on the PDMS surface to prepare PDMS/PDA to improve its biocompatibility. The PDMS/PDA was characterized by contact angle tester and scanning electron microscopy (SEM). The effect of curvature on bone cell migration and differentiation was studied through SEM, inverted phase contrast microscope and fluorescence microscopy. We found that different curvatures had different effects on the bone cell migration and differentiation. Chondrocytes migrated rapidly in grooves with a curvature range of 1/575–1/875 μm⁻¹. Bone mesenchymal stem cells (BMSCs) had high efficiency of differentiation into chondrocytes in the grooves with a curvature range of 1/775–1/1375 μm⁻¹. Furthermore, BMSCs showed high efficiency of differentiation into chondrocytes at the edges of micro-nano patterns with different perimeter curvatures, and the differentiation efficiency was the highest at 120° convex curvature. This work shows that curvature is a principle to be considered in bone tissue regeneration engineering and provides inspiration for future biomaterials design.     

Novel synthesis method and microstructure evolution of Ti3C2(OH)2/K2Ti8O17 nanocomposites as an effective surface enhanced Raman scattering substrate

In this paper, we have developed a mild and facile approach using KOH solution as etchants to corrode Ti₃SiC₂ at room temperature, fabricating novel Ti₃C₂(OH)₂/K₂Ti₈O₁₇ nanocomposites with open network structures and abundant surface functional groups. The as-produced products obtain the excellent surface enhanced Raman scattering (SERS) performance in the determination of crystal violet (CV), rhodamine 6G (R6G) and methylene blue (MB) dye molecules. The enhancement factors of the three can be calculated to be 3.98 × 10⁵, 1.78 × 10⁵ and 5.27 × 10⁵, and the Raman signals can be detected at the concentrations as low as 10^?6 M, 10^?8 M and 10^?6 M, respectively, suggesting the potential for reliable SERS substrates. In this regard, this work provides a new strategy for exploring and synthesizing MAX phase-derived nanomaterials as promising SERS substrates for high-sensitive molecular detection.     

Mechanical properties and translucency of a multi-layered zirconia with color gradient for dental applications

In this work, the properties of yttria-stabilized zirconia-based ceramics, Y-TZP containing Fe₂O₃ as coloring agent were evaluated. Nanoparticled powder of 3Y-TZP (ZrO₂ - 3 mol.% Y₂O₃) doped with different amounts of Fe₂O₃ (0.002–0.136 wt%) were compacted into monolithical or multilayered samples and sintered at 1475 °C - 2 h. The samples were characterized by X-ray diffraction analysis (XRD), relative density, scanning electron microscope (SEM). Hardness and fracture toughness in the color interface were investigated using the Vickers indentation method and the biaxial flexural strength was determined by the piston on 3 balls method (P–3B). Furthermore, optical parameters were measured using spectrophotometry in regard to sample thickness and Fe₂O₃ content. The results indicated a good adhesion between layers, proven by indentation cracks randomly growing between different regions, because the powders used produced very similar morphological characteristics. The different amounts of Fe₂O₃ studied in this work did not interfere in densification, phase composition, or microstructure of the sintered ceramics. The fracture toughness and flexural strength did not significantly change due to the addition of Fe₂O₃, presenting values close to 7 MPa m^1/2 and 1120–1150 MPa, respectively, in all studied compositions. On the other hand, increasing Fe₂O₃ contents lead to an increase in the hardness of the material (1280–1330 H V), and higher contrast ratios (CR) with a consequent loss of translucency. Color variation (ΔE) depended also on the thickness of the material.