The Tunable Rhenium Effect on the Creep Properties of a Nickel-Based Superalloy.

Atomistic simulations on the creep of a nickel-based single-crystal superalloy are performed for examining whether the so-called rhenium effect can be tuned by changing the spatial distribution of rhenium in the nickel matrix phase. Results show that Rhenium dopants at {100} phase interfaces facilitate mobile partial dislocations, which intensify the creep, leading to a larger creep strain than that of a pure Ni/Ni3Al system containing no alloying dopants. If all the Re dopants in the matrix phase are far away from phase interfaces, a conventional retarding effect of Re can be observed. The current study implies a tunable Re effect on creep via dislocation triggering at the phase interfaces.

Stability and Digestive Properties of a Dual-Protein Emulsion System Based on Soy Protein Isolate and Whey Protein Isolate.

The stability and digestive properties of a dual-protein emulsion consisting of soy protein isolate (SPI) and whey protein isolate (WPI) have been systematically studied. The results showed that the particle size and viscosity of the dual-protein emulsion system decreased continuously with the increase in WPI, and this might be related to the large amount of electric charge on the surface of the emulsion droplets. Dual-protein emulsions with ratios of 3:7 and 5:5 showed the highest emulsion activity, while emulsion stability increased with the increase in WPI. The thicker adsorption layer formed at the interface might have contributed to this phenomenon. After in-vitro-simulated digestion, the emulsion droplet particle size increased substantially due to the weakened electrostatic repulsion on the droplet surface, especially for the intestinal digestion phase. Meanwhile, WPI accelerated the release of free fatty acids in the digestion process, which played a positive role in the nutritional value of the dual-protein emulsion. In accelerated oxidation experiments, WPI also improved the antioxidant properties of the dual-protein emulsion system. This study will provide a new insight and necessary theoretical basis for the preparation of dual-protein emulsions.

The Plastic Deformation Mechanisms of hcp Single Crystals with Different Orientations: Molecular Dynamics Simulations.

The deformation mechanisms of Mg, Zr, and Ti single crystals with different orientations are systematically studied by using molecular dynamics simulations. The affecting factors for the plasticity of hexagonal close-packed (hcp) metals are investigated. The results show that the basal dislocation, prismatic dislocation, and pyramidal dislocation are activated in Mg, Zr, and Ti single crystals. The prior slip system is determined by the combined effect of the Schmid factor and the critical resolved shear stresses (CRSS). Twinning plays a crucial role during plastic deformation since basal and prismatic slips are limited. The 101¯2 twinning is popularly observed in Mg, Zr, and Ti due to its low CRSS. The 101¯1 twin appears in Mg and Ti, but not in Zr because of the high CRSS. The stress-induced hcp-fcc phase transformation occurs in Ti, which is achieved by successive glide of Shockley partial dislocations on basal planes. More types of plastic deformation mechanisms (including the cross-slip, double twins, and hcp-fcc phase transformation) are activated in Ti than in Mg and Zr. Multiple deformation mechanisms coordinate with each other, resulting in the higher strength and good ductility of Ti. The simulation results agree well with the related experimental observation.

Effects of pulsed ultrasound on rheological and structural properties of chicken myofibrillar protein.

The effects of pulsed ultrasound (PUS) (power: 240w) with varying time (0, 3, 6, 9, 12 and 15min) on rheological and structural properties of chicken myofibrillar protein (CMP) were examined. PUS treatment significantly caused a decrease in the viscosity coefficients (k) but an increase in the flow index (n) value of CMP solutions within short time (0-6min), while had no significant effect for longer time (9-15min). Besides, at 6min, the solubility and microstructure of CMP samples were optimum. The primary structure of CMP was not altered by PUS treatment. However, Raman spectroscopy revealed a decrease in the α-helix and ß-sheets proportion and an increase in the ß-turn of CMP following PUS treatment. Random coil reached a maximum at 6min. The changes in tertiary and quaternary structure of CMP by PUS treatment also occurred. As PUS time extended, S0-ANS for CMP increased measured by ANS fluorescence probe method. However, the normalized intensity of 760cm-1 increased from 0min to 6min, and then decreased to 15min by Raman test. Moreover, the reactive sulphur (SH) contents and disulfide bonds (S-S) of samples increased while the total SH contents decreased within 0-6min. At 9min and above, the contents of reactive SH groups were almost equal to the contents of total SH groups. Differential scanning calorimetry (DSC) of CMP showed that peak temperature (Td2) for myosin and peak temperature (Td3) for actin were both reduced in the first 6min, while Td3 was not observed from 9min following PUS treatment. Therefore, 6min was the optimum PUS time to obtain better CMP rheological and structural properties.