The objective of this study was to determine the effects of the myofibrillar protein (MP) characteristics from tilapia, hairtails, and squid on gel properties, microstructure, and emulsification ...stability of surimi gels with increasing concentrations of fish oil (FO). The surface hydrophobicity (38 μg) of the squid MP was significantly lower than that of the tilapia and hairtail (P < 0.05), and its content (21 g/100 g) and emulsification characteristics were significantly higher than those of the tilapia and hairtail (P < 0.05). Combined with the firmer structure of the squid surimi in the microstructure more intuitively indicated FO occupied the void spaces of the squid protein matrix, revealed the interaction between FO and MPs. Moreover, infrared spectroscopy (FT-IR) and texture analysis demonstrated that tilapia MPs had the highest β-sheet (18%) and β-turn (39%) contents and the lowest α-helix (23%) content compared with the hairtail and squid. Contributed to higher gel strength, reflecting the influence of secondary structure of MPs on the texture of surimi. These results further elaborated the effects of MPs’ structure on surimi emulsified FO and the mechanism of FO on surimi gel, which is meaningful for functional surimi production.
•Fish oil has different effects on different surimi.•Squid myofibrillar protein emulsifying properties were higher than that of hairtail and tilapia.•Fish oil (10 g/100 g of surimi) improved the microstructure of squid and hairtail.•Tilapia surimi gel performance was better than hairtail and squid.
Post-harvest rot causes enormous economic loss to the global kiwifruit industry. Currently, there are no effective fungicides to combat the disease. It is unclear whether silver nanoparticles (AgNPs) ...are effective in controlling post-harvest rot and, if so, what the underlying antifungal mechanism is. Our results indicated that 75 ppm AgNPs effectively inhibited the mycelial growth and spore germination of four kiwifruit rot pathogens:
Alternaria alternata
,
Pestalotiopsis microspora
,
Diaporthe actinidiae
, and
Botryosphaeria dothidea
. Additionally, AgNPs increased the permeability of mycelium’s cell membrane, indicating the leakage of intracellular substance. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that AgNPs induced pathogen hypha shrinkage and distortion, as well as vacuolation in hypha cells, implying that AgNPs caused cellular and organelle structural degradation. The transcriptome sequencing of mycelium treated with AgNPs (24 h / 48 h) was performed on the Illumina Hiseq 4000 sequencing (RNA-Seq) platform. For the time points of 24 h and 48 h, AgNPs treatment resulted in 1,178 and 1,461 differentially expressed genes (DEGs) of
A. alternata
, 517 and 91 DEGs of
P. microspora
, 1,287 and 65 DEGs of
D. actinidiae
, 239 and 55 DEGs of
B. dothidea
, respectively. The DEGs were found to be involved in “catalytic activity,” “small molecule binding,” “metal ion binding,” “transporter activity,” “cellular component organization,” “protein metabolic process,” “carbohydrate metabolic process,” and “establishment of localization.” Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis also revealed that “carbohydrate metabolism,” “amino acid metabolism,” “energy metabolism,” and “xenobiotics biodegradation and metabolism” of “metabolism processes” were the most highly enriched pathways for these DEGs in four pathogens, with “cellular processes” being particularly enriched for
B. dothidea.
Furthermore, quantitative polymerase chain reactions (qPCRs) were used to validate the RNA-seq results. It was also confirmed that AgNPs could significantly reduce the symptoms of kiwifruit rot without leaving any Ag
+
residue on the peel and flesh of kiwifruit. Our findings contributed to a better understanding of the antifungal effect and molecular mechanisms of AgNPs against pathogens causing kiwifruit post-harvest rot, as well as a new perspective on the application of this novel antifungal alternative to fruit disease control.
An Alx(TiZrTa0.7NbMo) (x = 0, 0.1, 0.2, 0.3, 0.4, and 0.5) series of refractory high-entropy alloys were prepared by a vacuum-arc melting process and annealed. The effects of aluminum (Al) addition ...on the microstructure, room temperature, and high temperature mechanical properties of refractory high-entropy alloys were systematically examined and the strengthening mechanism analyzed and discussed. The results showed that, the phase composition of the alloy was BCC1 and BCC2 phases in the absence of Al. Precipitated phase AlZr3 formed in the alloy when Al was added. This series of refractory high entropy alloy has good strength at room temperature and high temperature. The compressive yield strength of Al0.5(TiZrTa0.7NbMo) alloy at room temperature was 1984 MPa and the compressive yield strength at 800 °C was 714 MPa. All alloys have plastic strain variables of 10.2–34.8 %, showing excellent room temperature plasticity. The increase in yield strength at room temperature primarily resulted from solution and precipitation strengthening. At high temperatures, precipitation strengthening became the dominant strengthening method. These research findings are expected to facilitate the understanding of the influence trends and mechanism of action of Al in refractory high-entropy alloys and serve as a reference for the design and development of Al-containing refractory high-entropy alloys.
•The phase composition of the alloy was analyzed using the CALPHAD method.•The Alx(TiZrTa0.7NbMo) alloys had good balance for strength and plasticity.•The Al content of balance point between the strength and plasticity was 0.2 mol.•The solution and precipitation strengthening contribution value was calculated.
X-ray diffraction and SEM scanning are conducted to examine the alterations in sandstone under different saturation conditions to reveal the water-rock softening effect on sandstone from the Qilicun ...tunnels in China under varying saturation pressures. The mechanisms underpinning the strength softening of sandstone are analyzed using uniaxial compression tests. The experimental results demonstrated that after immersion in water, the internal cementing material within the sandstone dissolves, and the mineral particles fragment or disintegrate, increasing porosity. In the presence of water, the macroscopic compressive strength of sandstone exhibits a declining trend. Concurrently, as the saturation pressure escalates, the compressive strength diminishes by approximately 10%, the elastic modulus decreases by about 30%, and Poisson's ratio incrementally falls by about 25%. The sandstone's failure is characterized by both axial multiple splitting surface failure and shear failure surface. Finally, a strain-softening numerical model is employed to simulate the failure behaviors of sandstone under various saturation pressures. The findings indicated that the sandstone sample exhibits plastic failure characteristics under high saturation pressure.
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•The micro failure mechanism of sandstone is observed under different saturation pressure.•A strain softening numerical model is developed failure of sandstone.
•Filling the gaps of fatigue tests under non-proportional multiaxial random loading.•Elucidating the cyclic behaviors under different non-proportion factors.•Revealing the deformation mechanisms ...under various random loadings.•Proposing an effective life evaluation method for random loading conditions.
Fatigue tests on AISI304 stainless steel under non-proportional multiaxial random loading conditions were conducted with uniform hollow specimens at room temperature. The results revealed initial hardening and subsequent cyclic softening under uniaxial loadings and additional hardening under non-proportional multiaxial loadings. This shift from softening to additional hardening significantly reduced the failure life. Fractographic analysis and Electron Backscatter Diffraction (EBSD) observations identified planar slip as the dominant deformation mechanism under uniaxial loading. Multiple slip system activations, strong slip interactions, and martensitic transformation were key factors influencing changes in cyclic deformation behavior under non-proportional loadings. A novel life evaluation method based on the Itoh–Sakane (IS) method was established, demonstrating accurate evaluations for both uniaxial and non-proportional multiaxial fatigue life under random loading conditions.
•Combined with digital image correlation technique, a novel small-size S-shaped specimen was used to evaluate the shear properties and failure mechanisms of the titanium/steel bonding interface under ...quasi-static and dynamic loading.•The bonding interface strength increased with increasing strain rate, showing an obvious positive strain rate effect.•The fluctuation in shear strengths and failure strain of the titanium/steel bonding interface were due to the presence of non-uniform defects, (e g. cavities, cracks and brittle intermetallic etc.) formed on the bonding interface. Those defects as discontinuities and stress concentration points would result in degraded mechanical properties.•The fracture morphology revealed ductile-brittle mixed fracture patterns under both quasi-static and dynamic strain rates.•The S-shaped specimen has proven to be effective to measure the shear properties of the bonding interface of materials with small thickness.
The strengths of the welded composites are largely influenced by the bonding strengths of the explosive welding interfaces, which generally exhibit a periodic wavy shape. The measurement of the dynamic shear properties of the bonding interface is challenging due to the difficulties in preparing conventional shear specimens arising from the millimeter-sized thickness of the flyer plate. In this paper, small-sized (10 mm × 6 mm × 6 mm) S-shaped specimens were designed and machined to study dynamic shear properties and failure mechanisms of the bonding interface of explosively welded titanium/steel composite. Combined with digital image correlation technique, quasi-static (0.001 s − 1) shear tests were conducted using the Instron MTS universal testing machine and dynamic (5000∼7000 s − 1) shear tests were performed using the split Hopkinson pressure bar apparatus. Besides, microstructure of the bonding interface was characterized by optical microscopy, scanning electron microscopy and energy dispersive spectrometer. According to experimental results, the strength of the bonding interface increased with an increase in strain rate, showing an obvious positive strain rate sensitivity. The fluctuation in shear strengths and failure strains of the bonding interface was due to the presence of non-uniform defects (e g. cavities, cracks and brittle intermetallic etc.). Those defects were discontinuities and may act as stress concentration points leading to degraded mechanical properties. The fracture morphology revealed ductile-brittle mixed fracture patterns under both quasi-static and dynamic strain rates. Failure mainly occurred in the bonding interface near the titanium (TA2) side, which showed microcracks, cleavage plane, tearing ridges, dimples and fragmentation of brittle intermetallic compounds. In addition, the S-shaped specimen was proven to be effective to measure shear properties of the bonding interface of explosively welded composites with small thicknesses.
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How to overcome fastly and reliably the challenges to foster the lithium-based salts exploitation for latent heat storage technologies? In situ and real time microscopy is used to understand the ...discrepancies between the theoretical and experimental macroscopic properties of materials via the microscopic mechanisms. The feasibility of this method on the inorganic lithium salts is demonstrated despite their air/moisture-sensitivity and the common belief pretending that LiOH cannot be used for the synthesis of new materials inside the microscope chamber due to its decomposition in dry environment or under vacuum. The deviation source of ~30% from the theoretical energy density of 434 kWh/m3 has been investigated through the case study of Li4Br(OH)3, an uncommon promising phase change material. The hydration/dehydration of the starting materials appears as one of the main parameters, with applied temperature protocols, eliciting the deviation towards different materials from the targeted one of interest, in terms of morphology and properties. This criterion, if not taken into account, could be disastrous for the storage capacity of a unit during its use. This study highlights solutions to avoid these deficiencies. The results consistency at microscale with those obtained at macroscale is also proved despite the different operating conditions
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•An inorganic Li-salts study to foster the further design of sensible and latent thermal energy storage units is presented.•Highlighting of the LiOH distorted lattice, before melting, impacting its reaction with LiBr.•Advanced phase change material: Li4Br(OH)3 in situ/real time observations, charted in the current LiOH/LiBr phase diagram.•Highlighting of two Li4Br(OH)3 structures, each with its own final macroscopic properties.•LiOH decomposition impact on the attempt of Li4Br(OH)3 formation: deviation towards a new phase.
This work deals mechanical and tribological properties of pure copper, reinforced by various weight percentages of tin, before and after the application of equal channel angular pressing. It is found ...that the hardness, yield, and ultimate shear strengths are considerably improved through ECAP due to grain refinement. The effect of ECAP process on mechanical properties of dilute copper alloys is more significant than that of the pure condition. Also, the strengthening behavior is slightly intensified by increasing the amount of tin content in pure copper. Additionally, work-hardening potential of CPCu is restricted due to the ECAP process and also, through the production of dilute copper alloys. The results showed that the effect of ECAP on friction coefficient reduction is more sizeable than making the dilute alloys. Furthermore, the reduction of electrical conductivity in the deformed materials relies on the lattice distortion increase of copper due to the addition of Sn to Cu and the increment of dislocations density. Finally, ECAP procedure and alloying together, terminate to the better wear response of the materials.
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•Effect of ECAP on mechanical properties of dilute alloys is more significant than that of the pure condition.•Sample strengthening is intensified by increasing the amount of tin into the pure Cu.•The work-hardening potential of CPCu decreases due to the ECAP process and the making of dilute alloys.•ECAP process on friction coefficient reduction is more sizeable than making dilute alloys.•ECAP process and alloying lead to the better wear resistance of samples.
Biomass structure and reactivity of torrefied products are a matter of great concern to explore the fuel properties, pyrolysis characteristics, and microcosmic appearance, and life cycle assessment ...(LCA) is of great importance to evaluate the environmental impact of the torrefaction process. This study investigates the properties and microstructure of torrefied rice straw, including fuel properties, pyrolysis kinetics, crystallinity, surface functional group changes, and microscopic appearance. Results show that a good linear distribution appears between the comprehensive pyrolysis index (CPI) and atomic H/C ratio, and CPI and crystallinity index (CrI). Fourier transform infrared spectra depict dehydration, decarboxylation, and decarbonylation occur during the torrefaction process. The scanning electron microscope images illustrated the surface characteristics are closely related to the release of volatiles during the torrefaction process. The solid 13C NMR spectra of raw and torrefied rice straw reflect that the aromaticity will improve with increasing the torrefaction severity. For LCA analysis, the environmental impact of the torrefaction process shows a positive correlation with torrefaction temperature, and the global warming potential is in the range of 0.1469–0.2707 kg CO2 emission. This study is meaningful for the evaluation of fuel properties and torrefaction performance as well as microstructure and reactivity of torrefied rice straw.
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•Torrefaction improves the thermal stability of torrefied rice straw with devolatilization.•CPI can act as the predictors of atomic H/C ratio and CrI during the torrefaction process.•Dehydration, decarboxylation, and decarbonylation are accomplished in torrefaction.•The aromaticity of rice straw is improved by torrefaction.•The value of global warming potential is in the range of 0.1469–0.2707 kg CO2 emission potential.
The quality of potato chips is highly dependent on the mechanical properties of the dough sheet produced prior to frying. It has been well established that poor mechanical properties result in ...fragile dough sheets and associated high product wastage. However, the effect of the rolling process on the mechanical properties of the dough is unknown so the optimum rolling process can only be obtained via a trial and error approach. This work reports for the first time the effects of dry flake size and rolling parameters on the mechanical performance of potato dough sheets. The laboratory scale rolling setup used a 10 cm roller diameter with a 0.2 mm gap height. Furthermore, an experimental method was developed enabling rigorous tensile testing of fragile potato dough sheets. The mechanical performance of the potato dough sheets was anisotropic, as the Young's modulus and strength were 35% and 57% higher across the rolling direction than those along the rolling direction, respectively. The formability, i.e. the ability to form a coherent sheet of the potato dough is improved by using smaller dry flakes (<500 μm). However, further decrease in the flakes size had no effect on the mechanical behaviour of potato dough sheets, i.e. flakes with diameter smaller than 212 μm showed similar tensile response to flakes smaller than 500 μm. Rolling the dough increases the coherence and the strength of the potato dough sheets, but also introduces defects orientated across the rolling direction which decrease the strength if the dough is rolled too many times. For example, sheets rolled for seven passes showed over 100% improvement in failure stress comparing to sheets rolled for five passes, but when the sheets were rolled for the eighth pass, the failure stress dropped by 17%. Due to the viscoelasticity of the dough, both the tensile modulus and strength of the sheets are higher when tested at higher strain rate. In addition, at higher strain rate, the defects in the sheets did not have enough time to grow, as evidenced by a lower scatter in failure stress. A method to obtain an optimum production condition has been identified, which will lead to fewer production interruptions due to dough breakage, and reduced waste.
•Investigation on the effect of rolling process on the mechanical behaviour of thin potato dough sheets.•First research on the dry potato flake size-potato dough sheet property relationship.•Design of a novel test gear to perform tensile tests on potato dough sheets and other fragile materials.•Study on the mechanical behaviour of potato dough sheets after rolling process with high compression rate.•Microstructure observation to identify how the change in potato dough microstructure affects the mechanical performance.
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