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We present a novel formalism to characterize elastic heterogeneities in amorphous solids. In particular, we derive high-order strain-energy expansions for pairwise energies under athermal quasistatic dynamics. We then use the presented formalism to study the statistical properties of pairwise expansion coefficients and their link with the statistics of soft, quasilocalized modes, for a wide range of formation histories in both two- and three-dimensional systems. We further exploit the presented framework to access local yield stress maps by performing a non-linear stress–strain expansion within a cavity embedded in a frozen matrix. We show that our "bond micromechanics" compare well with the original "frozen matrix" method, with the caveat of overestimating large stress activations. We additionally show how local yield rules can be used as an input for a scalar elasto-plastic model (EPM) to predict the stress response of materials ranging from ductile to brittle. Finally, we highlight some of the limits of simple mesoscale models in capturing the aging dynamics of post-yielding systems. Intriguingly, we observe subdiffusive and diffusive shear band growths for particle-based simulations and EPMs, respectively. [ABSTRACT FROM AUTHOR]

The ice surface is known for presenting a very small kinetic friction coefficient, but the origin of this property remains highly controversial to date. In this work, we revisit recent computer simulations of ice sliding on atomically smooth substrates, using newly calculated bulk viscosities for the TIP4P/ice water model. The results show that spontaneously formed premelting films in static conditions exhibit an effective viscosity that is about twice the bulk viscosity. However, upon approaching sliding speeds in the order of m/s, the shear rate becomes very large, and the viscosities decrease by several orders of magnitude. This shows that premelting films can act as an efficient lubrication layer despite their small thickness and illustrates an interesting interplay between confinement enhanced viscosities and shear thinning. Our results suggest that the strongly thinned viscosities that operate under the high speed skating regime could largely reduce the amount of frictional heating. [ABSTRACT FROM AUTHOR]

Absolute measurements of solid-material compressibility by magnetically driven shockless dynamic compression experiments to multi-megabar pressures have the potential to greatly improve the accuracy and precision of pressure calibration standards for use in diamond anvil cell experiments. To this end, we apply characteristics-based inverse Lagrangian analysis (ILA) to 11 sets of ramp-compression data on pure platinum (Pt) metal and then reduce the resulting weighted-mean stress–strain curve to the principal isentrope and room-temperature isotherm using simple models for yield stress and Grüneisen parameter. We introduce several improvements to methods for ILA and quasi-isentrope reduction, the latter including calculation of corrections in wave speed instead of stress and pressure to render results largely independent of initial yield stress while enforcing thermodynamic consistency near zero pressure. More importantly, we quantify in detail the propagation of experimental uncertainty through ILA and model uncertainty through quasi-isentrope reduction, considering all potential sources of error except the electrode and window material models used in ILA. Compared to previous approaches, we find larger uncertainty in longitudinal stress. Monte Carlo analysis demonstrates that uncertainty in the yield-stress model constitutes by far the largest contribution to uncertainty in quasi-isentrope reduction corrections. We present a new room-temperature isotherm for Pt up to 444 GPa, with 1-sigma uncertainty at that pressure of just under ± 1.2 % ; the latter is about a factor of three smaller than uncertainty previously reported for multi-megabar ramp-compression experiments on Pt. The result is well represented by a Vinet-form compression curve with (isothermal) bulk modulus K 0 = 270.3 ± 3.8 GPa, pressure derivative K 0 ′ = 5.66 ± 0.10 , and correlation coefficient R K 0 , K 0 ′ = − 0.843. [ABSTRACT FROM AUTHOR]

The demand for applications, such as coatings, separation filters, and electronic packaging, has greatly driven the research of polymer films. At nanometer scale, mechanical properties of thin polymer films can significantly deviate from bulk. Despite outstanding progresses, there still lack deep discussions on nonlinear viscoelastic–viscoplastic response and their interactions under nanoconfinement. In this work, by conducting measurements via the bubble inflation method and modelling using Schapery and Perzyna equations, we demonstrate nonlinear viscoelastic–viscoplastic properties of freely standing thin polystyrene (PS) films. The results show the unchanged glassy compliance and the rubbery stiffening phenomenon for thin PS films, where the lower rubbery plateau in rubbery stiffening may originate from the induced molecular orientation by plastic deformation. With decreasing film thickness, viscosity and yield stress in viscoplasticity increase in an exponential and a linear trend, respectively, indicating the significant role of nanoconfinement effect on viscoplastic properties. These findings may reveal that there are many properties from linear viscoelasticity to nonlinear viscoelasticity–viscoplasticity that need to be explored and unveiled for sufficient understanding of the nanoconfinement effect on altering mechanical behavior of polymers. [ABSTRACT FROM AUTHOR]

We present a method for computing locally varying nonlinear mechanical properties in particle simulations of amorphous solids. Plastic rearrangements outside a probed region are suppressed by introducing an external field that directly penalizes large nonaffine displacements. With increasing strength of the field, plastic deformation can be localized. We characterize the distribution of local plastic yield stresses (residual local stresses to instability) with our approach and assess the correlation of their spatial maps with plastic activity in a model two-dimensional amorphous solid. Our approach reduces artifacts inherent in a previous method known as the "frozen matrix" approach that enforces fully affine deformation and improves the prediction of plastic rearrangements from structural information. [ABSTRACT FROM AUTHOR]

In this study, the mechanical properties of a new hexagonal pyramid unit cell, including modulus of elasticity and yield stress with uniform porosity, are obtained using the HSDBT. This beam theory is used because of considering the effect of shear on the equations and increases the accuracy of the results. Furthermore, the mechanical properties are extracted by numerical modeling and the stiffness matrix methods of the structure using finite element software. In addition, elastic-plastic-damage behavior was implemented into a nonlinear finite element model, which tracks the compressive behavior of the lattice structure. The lattice structure was fabricated using the additive manufacturing method. Mechanical properties were studied using compressive tests and DIC. The outcomes of the developed analytical model indicate the enhanced accuracy of obtained results with the experiments. Finally, the effect of changes in the geometry parameter of the material's unit cell on the mechanical properties of the whole structure is evaluated. The results indicate that these changes have a significant effect on the mechanical properties of the entire structure. As a result, adequately determining geometric parameters, the convenient efficiency and suitable distribution of mechanical properties for the desired applications will be achieved. [ABSTRACT FROM AUTHOR]

This study investigates the enhancement of linear low‐density polyethylene (LLDPE) nanocomposites with multiwalled carbon nanotubes (CNT) at concentrations of 1, 3, and 6% w/w. To improve the interfacial interaction between the CNT and the polymeric matrix, CNT were treated using ethylene cold plasma (P‐CNT) in a rotary reactor. The incorporation of CNT into the polymer was carried out by a melt mixing process (MMP) and a sequential ultrasound dispersion method followed by melt mixing (UDM‐MMP). The thermal stability of nanocomposites with 6% P‐CNT increased by 45°C compared to pristine LLDPE. Electrical conductivity reached 2.5 × 10−2 S/cm for nanocomposites with 6% CNT. The elastic modulus increased from 519.52 MPa (LLDPE) to 714.63 MPa (6% CNT) and 795.43 MPa (6% P‐CNT), which further improving to 731.42 MPa (6% CNT) and 841.27 MPa (6% P‐CNT) using UDM‐MMP. Additionally, yield stress rose from 16.35 MPa to 21.28 MPa (6% CNT) and 22.06 MPa (6% P‐CNT), reaching 21.47 MPa and 22.28 MPa with UDM‐MMP. Tensile strength increased from 21.31 MPa to 25.15 MPa (6% CNT) and 25.9 MPa (6% P‐CNT), achieving 26.82 MPa (6% P‐CNT) with UDM‐MMP. These results highlight a significant improvement in conductivity, rigidity, and mechanical strength, emphasizing their potential for advanced applications. [ABSTRACT FROM AUTHOR]

Polymer materials exhibit vibration damping properties, yet scant research exists on their applicability to submarine tunnels. This study investigates the dynamic characteristics of Polymer Materials Resistant to Seawater Erosion (hereafter referred to as PMRSE) under varying conditions of density, confining pressure, strain rate, and erosion duration through dynamic triaxial tests. The results reveal an increase in material strength with a rise in density; enhanced strength and ductility with increasing confining pressure; and augmented strength and yield stress in correspondence with heightened strain rates. As confining pressure ascends, the equivalent damping ratio λd of PMRSE gradually diminishes. SEM and EDS indicate a porous structure for PMRSE, with a molded surface skin formed post‐manufacturing to thwart seawater erosion. The strain energy storage and energy absorption evaluation of PMRSE demonstrate its excellence as an energy‐absorbing material. Eventually, employing a numerical simulation model for a specific submarine tunnel reveals that the presence of a damping layer absorbs seismic energy and enhances the stress conditions of the secondary lining. PMRSE manifests as a strain‐rate sensitive material unaffected by seawater corrosion, which exhibits deformation characteristics of low yield strength and long yield stage. Accordingly, PMRSE proves suitable for vibration damping in submarine tunnels. [ABSTRACT FROM AUTHOR]

The investigation of the response mechanisms of Cyperus esculentus to water and salt stresses is crucial for the enhancement of the productivity of saline soils. Previous studies have indicated that plant hormones, antioxidant systems, and osmoregulation may contribute to the stabilization of yield. However, the contributions and interactions of these mechanisms remain poorly understood under combined water and salt stress in natural environments. A dual-factor (salt and water) orthogonal test was used to investigate the growth and biochemical responses of C. esculentus, under combined salt and water stress in a field experiment conducted on a typical saline area in northern China. The findings reveal that C. esculentus adjusted its biomass allocation strategies and activated hormone responses, antioxidant system, and osmoregulation mechanisms to maintain stable yield. Due to the negative synergism when salt and water stress coexist, the homogeneous limitations of both are weakened. Thus, the key to maintaining yields under combined water and salt stress may depend on indirectly enhancing tolerance to oxidative damage through abscisic acid, rather than focusing on accumulating low molecular weight osmoregulants and antioxidant enzymes to directly alleviate homogeneous limitations. Also, under combined salt and water stress, insufficient irrigation may have a greater impact on morphological characteristics than high salinity. The above results contribute to a deeper understanding of the process of adapting C. esculentus to combined salt and water stress. [ABSTRACT FROM AUTHOR]

This study employed genome‐wide association studies (GWAS) to identify the crucial marker–trait associations (MTAs) for agronomic and physiological traits in bread wheat grown under full irrigation and 40% reduced irrigation. One hundred twenty‐four genotypes derived from three‐way crosses of landraces and synthetic bread wheat were evaluated for 2 years in the field conditions of CIMMYT Obregon, Mexico. Irrigation was not provided at anthesis and post‐anthesis stage for the drought treatment, and data of 12 traits were recorded. Most of the traits were reduced significantly under drought conditions except for vigour, wax and spike length (SL); genotypes were significantly different for the eight traits except for days to heading (DTH), number of grains spike−1 (NGS), normalized difference in vegetation index (NDVI) and canopy temperature depression (CTD); and differences were also significant for five traits between the years. Moreover, GY was significantly and negatively correlated with wax and CTD. Our GWAS results indicated 117 significant (p ≤ 0.001) MTAs distributed on all the wheat chromosomes except chromosomes 4B and 4D explaining 10%–21.5% of the phenotypic variation of the corresponding traits. Moreover, 22 MTAs were recorded for grain yield and explaining the phenotypic variations up to 14.7% with one common association under both irrigated and drought conditions. Additionally, we also identified the associations for NDVI, CTD and SL at chromosome 1B, suggesting that genotypes are sustaining superior grain yield through better values of traits like NDVI, CTD, and SL under the challenging conditions of anthesis and post‐anthesis drought stress. [ABSTRACT FROM AUTHOR]

Background: This study investigated the effects of endurance exercise training and zoledronic acid (Zol) treatment on ovariectomy-induced osteopenia. Methods: Middle-aged female Wistar rats were subjected to sham and ovariectomy surgeries and assigned to seven different groups according to Zol treatment doses and treadmill endurance exercise (Ex) training; these were the Sham, Ovx, Ovx + LowZ, Ovx + HighZ, Ovx + Ex, Ovx + LowZ + Ex, Ovx + HighZ + Ex groups. The subcutaneous doses for the low- and high-Zol-treated ovariectomized rats were 20 and 100 µg/kg, respectively. Total intervention period was 10 weeks. Results: When comparing the Ovx groups to the Sham group, ovariectomy resulted in multiple compromises in bone histomorphometry, size-related measurements, and biomechanical properties. Two-way ANOVA was adopted to investigate the effects of Zol treatments and Ex on the six ovariectomized groups. In spongy bone histomorphometry, Zol treatment resulted in comprehensive preservation for all parameters, while exercise demonstrated benefits for osteoclastic number and mineralization activity. In serum marker assays, the Zol-treated rats had lower serum osteocalcin and IGF-1/IGFBP-3 molar ratio when compared to the non-treated rats. Exercise training significantly benefited metabolism through lower serum triglycerides, cholesterol, leptin, IGF-1 and IGF-1/IGFBP-3 molar ratio, along with increased IGFBP-3 and phosphorus (p < 0.05). In bone-size-related measurements and biomechanical property analyses, data were normalized to body weight. For whole bone strength, Zol treatments demonstrated higher bone fracture load (FL) and FL energy, while Ex showed benefits to yield load, FL, post-yield load energy, and stiffness. In tissue-level biomechanical properties, rats treated with the higher Zol dose were higher in yield stress and yield toughness. Exercise benefited most bone-size-related measurements, while the high Zol-treated rats showed smaller medullar area. Conclusion: When combined with Zol treatments, exercise training did not demonstrate significant collaborative or modifying effects. Exercise and bisphosphonate tend to affect to bone through distinct pathways. A lower dose or different timing of Zol treatment or during a later phase of bisphosphonate treatment (drug holiday) might allow the occurrence of synergistic effects between Zol treatment and exercise. [ABSTRACT FROM AUTHOR]

The study of the statistical trends on rainfall and temperature is much more efficient for hydrological design and planning for scarce water availability zones. In the present study, the sequential Mann–Kendall test (SqMKT) on the Mat-Lab platform is used to study the pattern of rainfall series and temperature series data of the Tikamgarh area of India, surrounded by five stations (nearby) from 2000 to 2020. The SqMKT is mainly used to perform non-linear trends on the rainfall and temperature series. In the SqMKT analysis on rainfall series projects, there was no significant trend in all months, except in the month of June. These months have intersecting points, and each point has Z values in the range of –0.5 < Z < 1.5. The SqMKT analysis on the temperature series shows a significant trend in the months of April, June, July and December, respectively, whereas the remaining months do not have any pattern or trend, similar to the rainfall series and temperature series have u values in the range of –0.5 < u < 1.5. The global climatic pattern is somewhat directly or indirectly connected to the Indian climate pattern, which results in variations in rainfall and temperature patterns from year to year. The indefinite variation in rainfall and temperature results in a direct impact on crop yield and crop water demand or total water availability. [ABSTRACT FROM AUTHOR]

Effects of polycarboxylate ethers (PCEs) with different charge densities on the time-dependent rheological property (yield stress) were systematically investigated by correlating the charge density of PCE with its adsorption behavior, dispersion capability (including the dispersion rate and dispersion extent), and packing density, fluidity, and hydration kinetics of the cement slurry. Results show that with the increase of charge density, the adsorption rate of PCE increases, which is attributed to the increase of affinity between PCE and cement particles. Based on this, the dispersion rate of PCE is effectively enhanced by increasing its density charge, which results in a faster packing rate, consequently lowering the decrease of the time-dependent yield stress of cement slurry and increasing the fluidity loss over time. Noticeably, the stronger affinity raised from higher charge density leaves fewer PCEs in the solution of cement slurry, which is remarkable at high dosage, and thus leading to a faster fluidity loss or time-dependent yield stress increase. This will also lead to slower hydration kinetics with the same PCE content. These findings can provide guidance for the design of PCE structures in regulating the workability of concrete. [ABSTRACT FROM AUTHOR]

When a soil is subjected to cyclic loading, there are changes in the material's geomechanical behaviour that need to be characterised before safely designing any future projects. In terms of cyclic loading, it is important to characterise not only the failure of the soil but also its behaviour before failure, in particular the yield point and the elastic behaviour of the material. This study examines the effects of the number of loading cycles on the behaviour of a chemically stabilised soft soil with a particular focus on the yield surface. To this end, a series of triaxial tests were performed on specimens, previously or not subjected to a different number of loading cycles (1000–100 000). The results were analysed in terms of the evolution of accumulated permanent axial strain, the yield surface and stress–strain behaviour. It was observed that an increase in the number of loading cycles promoted: an increase in the permanent axial strain, an increase in the undrained resilient modulus, a shrinkage of the yield surface but its shape is maintained, and there is a small increase in the peak strength of the stabilised soil explained by the strain-hardening effect induced by the cyclic loading. [ABSTRACT FROM AUTHOR]

The evaluation of the use of sawdust in drilling fluid formulation is covered in this study. The investigation focused on the physicochemical and rheological properties of water-based mud (WBM) drilling fluids that included four different dosages of sawdust. These properties included yield stress, plastic viscosity, rheological behavior, gel strength, filtration test (API filtrate; American Petroleum Institute), and pH. The sawdust was employed as a substitute for the polymers commonly used in water-based muds (WBMs) to serve either as a viscosifier or as a fluid loss controller. The current study set out to evaluate how sawdust (diameter ≤630 µm) affected the primary characteristics of the drilling muds. Sawdust was utilized in place of carboxymethyl cellulose polymer (CMC) as a viscosifier and polyanionic cellulose polymer (PAC) as a filtrate reducer at several dosages (0, 10, 20, 50, and 100 g/L). It was found that the sawdust dosage and its role had a significant impact on the rheological characteristics of the drilling fluids. At amounts between 20 and 50 g/L, the sawdust was added as a viscosifier to the drilling fluids under study, resulting in a significant improvement in their physicochemical and rheological parameters (yield stress, plastic viscosity, and gel strength). However, the drilling fluids showed extremely high rheological properties and a viscosity that can slow down fluid circulation in the well when 100 g/L of sawdust were used, totally substituting for the polymers. [ABSTRACT FROM AUTHOR]

By incorporating polar fibers into the design of electrorheological (ER) fluids, a 130% performance improvement can be achieved with the addition of only 0.8 vol% of polar long fibers. We quantitatively analyzed the impact of relatively long fibers on improving ER performance by measuring the yield stress, shear stress, and current density after adding fibers. Both optical microscopy and transmission electron microscopy were used to observe and analyze the interaction between ER particles and polar fibers. The results indicate that, under the influence of an electric field, the fibers transform the one-dimensional chain-like structure into a two-dimensional mesh structure, greatly improving the ER performance. The transformation of structure induced by the polar fibers in the ER fluids amplifies the ER effect. However, the inclusion of non-polar fibers does not contribute to this enhancement, as a point of comparison. Moreover, to ensure the universality of this method, we used two different types of ER fluids in experiments. The utilization of this method offers a straightforward, environmentally friendly, and highly effective approach. Furthermore, this study provides a novel technical solution aimed at enhancing the performance of ER fluids. [ABSTRACT FROM AUTHOR]

After the application of Zn–SA–chitosan bionanoconjugates (BNCs), the physio-biochemical responses of two wheat varieties WH-1124 (heat resistant) and WH-542 (heat sensitive) under terminal heat stress(THS) were assessed in the current study. Zn (Zinc) and SA (Salicylic acid) were slowly released by BNCs to maintain nutrient availability for plants.Application of BNCs enhanced wheat production by enhancing seedling emergence, seed vigour index, and cellular redox homeostasis through antioxidant status regulation, enhanced photosynthetic rate, and cellular and osmotic stability which are essential for stress resistance and plant growth. BNCs (0.01–0.16% w/v) administration at booting and anthesis stages fabricated cellular homeostasis by reducing oxidative damage by suppressing malondialdehyde (MDA), and hydrogen peroxide (H2O2) restoring proline, and its metabolizing enzymes in flag leaf. Comparing control plants treated with, BNCs (0.08%) considerably slowed the loss of carotenoid and chlorophyll levels in both wheat cultivars. Furthermore, foliar treatment of BNCs boosted the activities of superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, and glutathione peroxidase in both flag leaf and developing grains on exposure of late sown wheat to THS. BNCs (0.08%) not only promoted early maturity but also significantly slowed the plant height reduction from 12.6% in the control group to just 8.7%. Similarly, the reduction in spike length with awns, and grain yield per pot was controlled to just 5.5% from 7.9% in control.Early emergence, vigorous germination, and early flowering by BNCs synergistically helped the wheat plant in mitigating THS and giving better productivity by providing enough time for grain filling. [ABSTRACT FROM AUTHOR]

Lead (Pb) toxicity is a major environmental threat that severely affects growth and production of staple crops. Foliar applications of glycine betaine (GB) have been extensively studied for their ability to stimulate heavy metals (HMs) tolerance in plants. Despite that, no literature reports are available on the ameliorative behavior of GB application on barley cultivars under Pb stress. A pot experiment was conducted to assess the relative efficacy of exogenous GB (2 mM) supplementation on various morphological (spike length) yield (no. of spikelet spike−1, no. of grains spike−1, grain yield plant−1, and 1000 grain weight) and grain quality traits (carbohydrate and protein content) of two barley cultivars (BH946 & BH959) under three levels of Pb stress treatments, viz. control, 15, 25, and 35 mM. Current research results revealed that Pb stress significantly (p < 0.05) decreased barley plants' yield traits and grain quality characteristics. More reduction was observed at the highest Pb stress, i.e., 35 mM. However, the foliar application of GB significantly (p < 0.05) mitigates the toxic effect of Pb stress and improves the yield traits, and ultimately, the grain yield per plant increases. Moreover, GB addition also enhances the quality of barley grain by improving the protein and carbohydrate content. The present research findings exhibit the ameliorative role of foliar-applied GB in enhancing the yield, and quality traits of barley cultivars might be attributed to modulating plant growth, photosynthetic activities, the antioxidant defense system, and diminished oxidative stress under Pb toxicity. According to the t-test results, both cultivars displayed the same trend under each stress and GB supplement. Therefore, only one cultivar can be considered for the experiment setup out of the two for further studies. In conclusion, GB at 2 mM concentrations successfully mitigates the toxic effect of Pb (up to 35 mM) and its implication might be recommended for crops suffering from Pb stress to improve their yield and quality traits. [ABSTRACT FROM AUTHOR]

Structures allowing their bases to uplift and rock during an earthquake event usually experience less damage; thus, they are more resilient to seismic hazards. Accurate simulation is critical to design and seismic performance evaluation of these flexible rocking structures. Motivated from this, this article presents a new rigid‐flexible coupled rocking model for numerical evaluation of flexible rocking structures under both cyclic and dynamic loadings. The key idea in the model formulation is that the total motion of flexible rocking structure can be decomposed into a rigid‐body motion and an associated flexible deformation. The flexible deformation of the rocking body is described using displacement field of classical Timoshenko beam. Using this approach and appropriate degrees‐of‐freedom (DOFs), the governing equations‐of‐motion for flexible rocking structures are formulated using the variational principle. Multiple springs with appropriate constitutive model are distributed along rocking base to represent the inelastic behavior of rocking body. Potential post‐tensioned tendons are also considered in this model. In addition, nonlinear stress distribution along the rocking base, which cannot be considered in existing flexible rocking model, is also incorporated in the developed model. The proposed model is subsequently validated against published experimental data through quasi‐static and shake table tests, showing good accuracy when the rocking structure is relatively stockier. Finally, a parametric investigation on the effect of flexibility, nonlinear stress distribution and yield stress of rocking body on the rocking response is performed. This preliminary investigation shows that influence of flexibility and yield stress is significant while impact of nonlinear stress distribution is minor. [ABSTRACT FROM AUTHOR]

In embedded 3D printing, the supporting gel must provide the right rheological properties to keep the ink in place. It has previously been shown that a strong and stable 3D network can be formed by particle–particle interactions of hydrophobic fumed silicas suspended in a polar solvent. Here, the rheological properties of fumed silica gels in polyethylene glycol (PEG) are investigated. The recovery properties like storage modulus, yield stress, and recovery time of the gels made of fumed silica with alkyl‐chains of different lengths are studied. A very fast recovery time (0.2 s) is achieved by increasing the length of the alkyl chains on the silica surface, leading to embedded printing results with high shape accuracy. However, with the engineered supporting gel, the formation of crevasses affects the shape of the filament. Previous approaches to reduce crevasse formation include the introduction of liquid fillers to avoid such distortions, which, however, prevents the reuse of the gels and leads to increasing waste production in embedded printing. Here, it is shown that by adjusting the rheology of the inks to fit the rheology of the supporting gel, high‐shape accuracy prints with ideally round‐shaped filaments can be achieved without the need for liquid fillers. [ABSTRACT FROM AUTHOR]

One of the key factors in manufacturing products by fused deposition molding (FDM) or layer-by-layer printing technology is the material intensity of the product. The task of reducing the amount of material required to manufacture a product without significant loss of mechanical properties is one of the most practically important technological tasks. Material saving in FDM printing of products allows to reduce financial costs and increase the speed of manufacturing of the final product without reducing (or not significantly reducing) the quality properties of the product. In our work it is demonstrated that using Combs filling type and materials of poly lactic acid (PLA) and polyethylene terephthalate glycol (PETG) it is possible to achieve material savings of up to 23% at 50% filling for PLA and 17% at 75% filling for PETG without significant reduction of product strength in comparison with other filling types. Exceptions are PLA samples with 100% fill and Lateral fill. Application of Kruskal-Wallis criterion and Dunn's criterion with Bonferroni multiple comparison correction showed that there were no statistically significant differences within the strength limits of samples made by FDM printing technology from PLA and PETG plastics (p-value = 0.0514), as well as samples with Triangle and Grid filling type (p-value = 1). Based on this result, three groups of samples statistically significantly differing in ultimate strength were identified by methods of hierarchical cluster analysis; in each group (except for group 1, which included samples made of PLA plastic with Lateral filling type and 100% filling), correlation analysis was performed (Spearman correlation was used). The results of the correlation analysis showed a stable average correlation between the percentage of filling, modulus along the secant 0.05–0.2% strain, ultimate strength and strain corresponding to the yield stress. Analysis of the correlation graph showed that the main parameter correlating with all mechanical properties of the specimen is the 0.05–0.2% strain modulus. Based on this conclusion, robust regression equations predicting the 0.05–0.2% strain modulus as a function of the percentage of specimen filling were constructed for the two selected groups. Analysis of the equations showed that in the third group of specimens, the average modulus of 0.05–0.2% strain is more than twice the modulus of 0.05–0.2% strain in the second group. The detected statistical regularities can be explained by the mechanism of strain hardening, the actual value of which depends on the structure of the macrodefect (type of filling), properties and volume of the material (percentage of filling) used in the fabrication of samples using FDM printing technology. [ABSTRACT FROM AUTHOR]

SUMMARY: Leaf senescence is a complex developmental process influenced by abscisic acid (ABA) and reactive oxygen species (ROS), both of which increase during senescence. Understanding the regulatory mechanisms of leaf senescence can provide insights into enhancing crop yield and stress tolerance. In this study, we aimed to elucidate the role and mechanisms of rice (Oryza sativa) LONG GRAIN 3 (OsLG3), an APETALA2/ETHYLENE RESPONSIVE FACTOR (AP2/ERF) transcription factor, in orchestrating dark‐induced leaf senescence. The transcript levels of OsLG3 gradually increased during dark‐induced and natural senescence. Transgenic plants overexpressing OsLG3 exhibited delayed senescence, whereas CRISPR/Cas9‐mediated oslg3 mutants exhibited accelerated leaf senescence. OsLG3 overexpression suppressed senescence‐induced ABA signaling by downregulating OsABF4 (an ABA‐signaling‐related gene) and reduced ROS accumulation by enhancing catalase activity through upregulation of OsCATC. In vivo and in vitro binding assays demonstrated that OsLG3 downregulated OsABF4 and upregulated OsCATC by binding directly to their promoter regions. These results demonstrate the critical role of OsLG3 in fine‐tuning leaf senescence progression by suppressing ABA‐mediated signaling while simultaneously activating ROS‐scavenging mechanisms. These findings suggest that OsLG3 could be targeted to enhance crop resilience and longevity. Significance Statement: RICE LONG GRAIN 3, an APETALA2/ETHYLENE RESPONSIVE FACTOR transcription factor, suppresses the abscisic acid signaling pathway and promotes reactive oxygen species scavenging, thereby controlling leaf senescence progression. [ABSTRACT FROM AUTHOR]

In this study, polymer composite nanofibers and thin membranes were synthesized using Carbon Nanotubes (CNTs) and Zinc Oxide (ZnO) as fillers in a Polyvinyl Alcohol (PVA) matrix, aiming to evaluate their electrical and mechanical properties. The composite nanofibers and thin membranes were prepared by incorporating different weight ratios of CNTs and ZnO into the PVA matrix using electrospinning and solution casting techniques, respectively. Solutions were prepared by mixing specific weight ratios of PVA, ZnO, and CNTs, followed by magnetic stirring and ultrasonication for homogenization. Electrospinning was performed at 20 kV with a syringe-to-collector distance of 14.5 cm at flow rate of 2.4 ml/hr. The composites were characterized using FTIR spectroscopy and Scanning Electron Microscopy (SEM). The PVA/5%ZnO/0.5%CNT composite exhibited the highest dielectric constant of 10.3 at high frequencies, while PVA/5%CNT showed the highest capacitance of 31.1 pF at 2 MHz. The maximum AC conductivity of 2.72 × 10− 7S/m was also observed for the PVA/5%ZnO/0.5%CNT composite. Mechanical testing revealed significant improvements in Young's modulus, stress yield, and load yield, with PVA/5%CNT achieving a Young's modulus of 387.12 MPa and a stress yield of 6.92 MPa. The addition of ZnO and CNT fillers resulted in enhanced electrical and mechanical properties, making these composites suitable for applications in microelectronic devices and packaging materials. [ABSTRACT FROM AUTHOR]

Flooding stress declines oxygen availability in roots that induce hypoxia stress in plants, thereby severely decline plant growth. Study was undertaken to clarify how potassium supplementation alleviates flooding stress in cotton plants. We applied potassium (K) fertilizer in pot soils at different levels; K0 = Control (No K), K1 = 30 mg kg−1, K2 = 60 mg kg−1 and K3 = 80 mg kg−1 with different duration of flooding stress s. D0 = Normal irrigation (0 day flooding), D1 = three days flooding, D2 = six days flooding, D3 = nine days flooding, D4 = twelve days flooding. The K supplementation (80 mg kg−1) in soil with 3-day flooding stress showed better combination for mitigating flooding stress. The supplementation of K3 dose (80 mg kg−1) alleviated flooding against 3-day initial flooding (D1) of which physiological traits showed better response compared to prolonged flooding stress (12-day flooding stress). The result suggests that K-involving flooding stress mitigation strategy in cotton plants was active for initial flooding stress (3-day flooding stress), while it was not fully active for pronged (upto 12-day flooding stress). Furthermore, we found K significantly improved antioxidant enzymes, photosynthetic performance, yield attributes, and lint quality. [ABSTRACT FROM AUTHOR]

Physical aging refers to relaxation of the polymer glassy state toward the amorphous state and this phenomenon affects their physical‐mechanical properties. This work investigates the effect of physical aging on polymer scratch behavior and visibility. It was shown that mechanical properties were significantly modified over the aging time, especially the yield stress, in turn affecting polymer scratch behavior. As a matter of fact, the critical load for the onset of scratch visibility was shown to increase with the aging, thus improving sensitivity of polymer to scratches. Such behavior was strictly related to the yield stress increase with the aging time. The usefulness of the present work is highlighted, and some future perspectives are discussed. [ABSTRACT FROM AUTHOR]

Highlights Considering their simplicity, processibility, and tunable rheological properties, polymer composite‐type precursors hold exceptional promise in the processing of polymers, ceramics, metals, and their composites. This large variety of precursors used in many different applications cover a large compositional space with dramatically varying rheological properties. Understanding how precursor composition influences their rheological properties is a key need towards streamlining the design and implementation of these precursors. With regard to this design advancement, this study elucidates the composition‐rheology relationships of graphene‐poly(ethylene) oxide (PEO) composite inks as a sample polymer composite‐type precursor. To this end, shear and extensional rheology of numerous compositions were studied across a wide compositional space, which varied graphene concentration, total solid concentration, and binder molecular weight. These studies showed that composition greatly affected various rheological parameters, such as the overall presence of yielding behavior. Specifically, this study illustrated the influence of (i) binder structure, (ii) total solid loading, and (iii) binder‐filler interactions on ink rheology. Extensional rheology was studied to examine how relaxation behaviors were dependent on composition and explicate how relaxation behaviors coincide with responses to shear forces. In tandem, our results illuminate significant composition‐rheology relationships in polymer composite‐type precursors. Rheology of polyethylene oxide‐graphene composite precursors were studied. Shear and extensional rheology, and their correlations were investigated. Composition‐binder molecular weight‐yielding relationships were elucidated. Extensional relaxation regimes were identified with respect to composition. Results can be used to determine compositional ranges for different processes. [ABSTRACT FROM AUTHOR]

ABSTRACT Advent of changing climatic conditions along with nutrient deficient soils adversely affects the environment for the rice production. Wild introgression lines derived from KMR3 and Oryza rufipogon population were evaluated in six environments, including optimum and low phosphorus stress condition. Significant differences among the introgression lines were observed for plant height, tiller number, biomass, grain yield per plant, days to 50% flowering and harvest index across the environments. Based on grain yield observed under optimum phosphorus and limited phosphorus (P stress condition), eight stress tolerance indices were calculated and found STI and GMP are the better indices to discriminate among tolerant and susceptible genotypes, and correlation studies also confirmed the significant association between STI and GMP. Cluster analysis based on stress tolerance indices revealed three different clusters distinguishing genotypes based on their stable performance on yield related traits. AMMI and GGE biplot analysis to identify the stable performance across environments revealed NSR60, NSR101, NSR105, NSR85 and NSR86 as high grain yielders, whereas NSR135, NSR5 and NSR88 as stable performers. WAASBY‐based stability analysis on multiple traits (MTSI) showed NSR135, NSR79 and NSR18 with lowest MTSI, indicating their high stability and high mean performance compared with parent KMR3. Further genotyping for low P tolerance gene (PSTOL1) and grain yield genes (Gn1a, SPIKE, TGW6, DEP1 and OsSPL14) using allele specific markers showed that the desirable alleles of SPIKE, Gn1a and TGW6 were derived from wild parent O. rufipogon. Low P tolerance allele PSTOL1 was absent in recurrent parent KMR3; however, the introgression lines harboured desirable alleles, which were derived from O. rufipogon. Further mapping studies will help to identify a significant potential QTLs/gene for low P tolerance from O. rufipogon. Wild introgression lines, NSR85, NSR124, NSR80, NSR54, NSR86 and NSR88, were found as the high yielding and nutrient stress tolerant genotypes, which can be used as potential donors in future breeding programmes for low P stress tolerance. [ABSTRACT FROM AUTHOR]

Cold stress is a critical factor affecting rice production worldwide. The application of cold-resistant agents may improve the cold resistance and yield of crops. To screen for suitable cold-resistant agents for machine-transplanted early rice, the effects of uniconazole, abscisic acid, and zinc-amino acids chelate and their spraying times (seed soaking stage, one leaf and one heart stage, two leaves and one heart stage, 7 days before the transplanting stage, and regreening stage) on the yield and cold resistance of machine-transplanted early rice were investigated. Moreover, the application method (spraying amount: 750 and 1125 g ha−1; spraying time: 7 days before the transplanting stage, transplanting stage, regreening stage, and transplanting stage and regreening stage) for the most suitable cold-resistant agent was optimized. The zinc-amino acids chelate was better than the other two cold-resistant agents for promoting rice tillering and increasing the leaf area index, dry matter weight, antioxidant enzyme activities (CAT, SOD, POD) and yield (i.e., 9.22% and 7.14% higher than uniconazole and abscisic acid, respectively), especially when it was applied in the regreening stage. The examination of spraying amounts and times indicated that the zinc-amino acids chelate dosage had no significant effect on the yield and cold resistance of early rice. However, the rice yield and antioxidant enzyme activities were highest when samples were sprayed once in the transplanting stage and the regreening stage. On the basis of the study results, 750 g ha−1 zinc-amino acids chelate applications in the transplanting and regreening stages of machine-transplanted early rice plants may be ideal for increasing cold stress resistance and yield. [ABSTRACT FROM AUTHOR]

Web buckling of steel plate girders creates an undesirable failure mode as it can limit the ultimate load capacity of plate girders. This paper presents details of an experimental investigation aimed at strengthening slender end panels of steel plate girders using three different types of fibre-reinforced polymer (FRP) composite materials (glass-fibre-reinforced polymer (GFRP) pultruded section stiffeners and woven carbon-fibre-reinforced polymer (CFRP) and GFRP fabrics). The plate girders were fabricated using non-rigid end posts and were tested in three-point bending. The test results showed an increase of up to 54% in the ultimate strength of the FRP-strengthened end panels compared with the non-strengthened control panel, which was the result of increased out-of-plane stiffness of the web. A breakdown of the bond between the steel and the FRP fabric occurred in the end panels strengthened with CFRP and GFRP fabrics, while no bond breakdown of the pultruded sections was observed at the ultimate load. Analytical methods proposed by some of the design codes underestimated the critical buckling load and overestimated the ultimate load of the non-strengthened end panel. [ABSTRACT FROM AUTHOR]

A series of blends of polyamide 6 (PA-6) (nylon-6) and a copoly(ether-ester) (HYTREL) were prepared by the melt-mixing method using a twin-screw extruder. The HYTREL content was varied from 0% to 25% by weight of the blends. Thermal and rheological studies on the blends using differential scanning calorimetry, dynamic mechanical analysis (DMA) and capillary rheometer showed that the blends are semi-compatible in nature. A two-phase globular morphology of the blends was established by scanning electron microscope (SEM) analysis. The matrix ligament thickness (interparticle distance) in each blend composition was measured from SEM images and compared with those calculated using Wu's equation. The impact strength of the blends as measured by the Izod impact test was found to be substantially improved as a result of the incorporation of HYTREL. The toughness determined by loss area calculation from the DMA spectrum showed similar trends. The toughness was found to be optimal in a blend having 15 wt.% HYTREL with an average dispersed particle size of around 450 nm. The yield stress of the blend decreased in comparison to PA-6 on addition of HYTREL, while the thermal stability of PA-6 remained unaffected. [ABSTRACT FROM AUTHOR]

The complexity of the chocolate matrix leads to it having characteristic rheological properties that may pose difficulties for its industrial manufacture. Many factors influence the flow behaviour of chocolates, such as raw materials, the amount of fat, the moisture content, particle-size distribution, the concentration of emulsifiers, or manufacturing conditions, among others. This study focusses on the rheological properties of an industrially manufactured chocolate with a 48% cocoa content, and the effect caused by the addition of two emulsifiers (soya lecithin and polyglycerol polyricinoleate (PGPR)) on the rheological properties. In the case of lecithin, a clear effect has been observed on the plastic viscosity and the yield stress. Plastic viscosity decreases until a concentration of 0.6% lecithin is reached, and thereafter remains relatively constant, while yield stress increases over the studied range. This effect is not observed when PGPR is used as the emulsifying agent. In this case, a small concentration of PGPR decreases the yield stress. Thixotropy was determined using the Casson model, and its behaviour was found to be similar to that of plastic viscosity with respect to changes in the PGPR and lecithin concentrations. Textural determinations were also carried out, relating the rheology characteristics to the texturometry. [ABSTRACT FROM AUTHOR]

This study analyzes the behavior of sodium polyacrylate (NaPA) as a rheological modifier for clay-based tailings. Special emphasis is placed on the impact of calcium and magnesium ions in industrial water, which are analyzed through rheograms, zeta potential measurements, and molecular dynamics simulations. The results are interpreted as electrostatic interactions, steric phenomena, and cation solvation. This interpretation integrates experimental studies with microscopic analyses, employing molecular dynamics simulations to elucidate the underlying mechanisms. In all cases, a decrease in the yield stress of synthetic slurries is observed as the dosing of NaPA increases due to greater repulsion between tailings particles through an increase in electrostatic repulsion and larger steric forces that hinder agglomeration. However, efficiency is reduced in the presence of divalent cations as zeta potential measurements suggest a reduction in the electrical charges of the particles and the polymer, making its application more challenging. The differences obtained in the presence of calcium compared to magnesium are explained in terms of the solvation of these ions and their impact on the polymer conformation in solution and adsorption on the mineral surfaces. This explanation is reinforced by molecular dynamics studies, which indicate that polymer adsorption on minerals depends on the type of mineral and type of ion. Particularly for quartz, the highest adsorption of NaPA occurs in the presence of calcium, whereas for a kaolinite surface, the highest polymer adsorption is obtained in the presence of magnesium. The competitive effect of these phenomena leads to the rheological behavior of the tailings being dominated by the effects originating in the clay. [ABSTRACT FROM AUTHOR]

The cement industry is of great importance in terms of raw materials consumed, energy consumed, and greenhouse gases emitted. Grinding aids (GA) are used to reduce energy consumption and costs, as well as to reduce the amount of CO2 released into the environment. In this study, the effect of GA-polycarboxylate ether-based water-reducing admixture (PCE) compatibility on some fresh, rheological and hardened state properties of cementitious systems was investigated. In order to investigate the rheological properties and thixotropic behavior of the mixtures, a total of 51 cement paste mixtures were prepared, containing 4 different types (molasses, MEG, DEA and ethanol) and ratios (0.025, 0.05, 0.75 and 0.1) of GAs and 2 different ratios (0.08% and 0.16%) of PCE in addition to the control mixture. In addition, the effect of the used GAs on the grinding efficiency and compressive strength value was investigated. Additionally, the predictability of the type of GA, dosage and cure time using the Taguchi method was investigated. It was determined that the highest grinding performance was obtained in mixtures containing MEG. It was determined that in cement paste mixtures containing GAs, the dynamic yield stress and viscosity values generally decrease with the increase in PCE usage rate up to a certain value, and these values may increase if the PCE usage increases further. It was determined that such behavior is not present in cement paste mixtures containing GAs and that the structural build-up value of the mixtures generally increases with the increase in the PCE admixture usage rate. It was determined that the use of GAs had a positive effect on 28-day compressive strength. [ABSTRACT FROM AUTHOR]

Thixotropy of cementitious materials is a crucial intrinsic property that determines the flowability and workability of cement-based grout. A novel virtual bond model of cement particles is developed in this paper to depict the thixotropy of cement grout. A particulate description of the reversible and erasable interparticle bonds is established based on experimental observations with a focus on the non-contact interactions mainly contributed in practice by calcium silicate hydrates (C–S–H). The structural breakdown of the cement network is realized through bonds breakage under applied motion, and the bonding network recovers with regeneration of interparticle connections that involve reversible hydrate reactions in the mixture. The balance between bond rupture and rebuilding can be tuned by assigning different strength limits for bond breakage. We have implemented this model in the open-source code Yade to carry out 3D discrete element method simulations of a rotational vane system filled with spherical particles, and the results show good agreement with experimental data. The modelling results reveal the transition from a solid-like structure to a fluid-like medium within cement suspensions caused by the evolution of broken interparticle bonds. The results also provide a distinct view of thixotropic variation upon disturbance. This model is extendable to other cohesive materials providing an explicit physical definition of the interparticle interactions. It also provides a theoretical explanation for the empirical estimations of thixotropy common in engineering industries and a potential means of measuring cementitious granular flow that may be useful in future studies. [ABSTRACT FROM AUTHOR]

Soil compaction is a serious threat to soil functions and ecosystem services. Persistent soil deformation takes place when mechanical stress exceeds soil strength. Risk assessment models typically assume soil to be elastic to a precompression stress level and plastic above this threshold. Currently used procedures for estimating soil precompression stress imply applied stress in a logarithmic form that has been criticized. We performed uniaxial, confined compression tests on 117 soil samples with a well‐defined stress history. Strain and stress were recorded at 200 levels of stress in the range of 0–1 MPa. Soil compressibility was calculated as incremental strain per incremental stress, using stress in arithmetic scale. For a given sample, a local minimum in compressibility appeared close to the preload applied to the sample prior to the compression test. This yield stress is suggested as an expression of soil precompression stress. Not all samples displayed a yield stress. Primarily soil exposed to a high preload did not exhibit a clear stress level with change in compressibility. This indicates that a physically based stress level pointing out a transition to plastic conditions will not exist for all soils. Our observation calls for new concepts in risk assessment. Tests with interpolation between a limited number of data points indicate that the yield stress—if existing—may be detected from classical compression data. [ABSTRACT FROM AUTHOR]

More has yet to be investigated on the physiological and yield responses of barley genotypes to the double stresses of drought and salinity affected by plant growth regulators (PGR) as the objective of the present research. A split split-plot with three replicates testing the main treatments of control (70 mm evaporation from class A pan with salinity of 4 dsm−1), salinity (70 mm evaporation from a class A pan with the salinity of 12 dSm−1) and drought (120 mm evaporation from a class A pan with salinity of 4 dsm−1) was conducted. The foliar application of water (control), zinc sulfate (5 gL−1), potassium sulfate (5 gL−1), salicylic acid (SA, 1.5 mM) and superoxide dismutase (SOD, 3 gL−1) were used as the subplots. The sub-subplots consisted of the three barley genotypes of Goharan, Armaghan and Mehr. Plant relative water, proline and protein contents were higher in salty conditions than drought conditions. There were significant differences among the genotypes in terms of physiological and yield responses. The results indicate the positive effects of Zn, SA and SOD in salt stress and K in drought stress conditions. Different PGR including K (60.7%), followed by SA (61.0%), Zn (63.7%) and SOD (63.7%) resulted in the least EL. The highest grain yield in salt stress was resulted by K (6766 kgha−1) and Zn (6690 kgha−1) and in drought stress by Zn (5262 kgha−1). The results indicate the positive effects of the tested PGR on the alleviation of the double stresses of salt and drought. [ABSTRACT FROM AUTHOR]

With the extensive use of manufactured sand and admixtures, it has been observed that as the shear rate increases, the shear rate–shear stress curve of some fresh wet shotcrete materials increasingly deviates from a linear correlation. It is necessary to study the rheological properties of wet shotcrete using a nonlinear model due to the large error when utilizing the Bingham model to describe the concrete. The torque-velocity curve of wet shotcrete was determined using an ICAR rheometer in this study. The experimental data was fitted using the Bingham model, Herschel-Bulkley (H-B) model, and modified Bingham (M-B) model, resulting in the determination of the associated rheological parameters. The M-B model exhibits the most optimal fitting effect, followed by the H-B model and the Bingham model. As the shear rate reaches a specific value, the M-B model consistently represents a higher degree of divergence from linearity compared to the H-B model. Furthermore, considering the limitations of the H-B model which includes varying dimension parameters, this study enhanced the calculation approach for determining the equivalent plastic viscosity based on Larrard et al.'s (Mat Struct 31:494–498, 1998) research. Ultimately, the impact of the mix parameters on the yield stress and plastic viscosity of the three rheological models was analyzed through the range approach. This study is beneficial for enhancing the comprehension of the rheological characteristics of wet shotcrete. [ABSTRACT FROM AUTHOR]

The yielding supports have been successfully used as a viable support solution in squeezing tunnels. When the lithological distribution of the formation exhibits non-uniformity, the stress on the yielding support becomes complicated and the yielding elements need to withstand not only axial compressive stress but also transverse shear stress. However, the design of previous yielding elements has often neglected consideration of the transverse shear force. To make yielding supports more suitable for tunnels in uneven squeezing ground, a honeycomb structure as yielding element is proposed due to excellent energy absorption and shear resistance. In this study, the mechanical response of honeycomb element is simulated by an equivalent orthotropic model, the plastic stage of honeycomb element is simulated by stiffness degradation method, and the mechanical characteristic parameters of the equivalent model are calculated by theoretical formula. Several numerical analyses are conducted to investigate the applicability of the honeycomb structure as a yielding element and to determine the optimal design size of the honeycomb element in uneven squeezing tunnels. According to the numerical simulation results, the honeycomb element can effectively resist transverse shear load whilst satisfying axial compression deformation. The use of honeycomb elements enhances the deformation capacity of the primary lining, significantly reduces internal compressive stress and overall plastic zone of the primary lining. The aspect ratio of the honeycomb element significantly influences the stress on the yielding support, and the optimal aspect ratio is determined based on the total failure zone of the lining. Highlights: A honeycomb structure with high transverse shear strength is proposed as the yielding element. The mechanical response of the honeycomb element is characterised using an orthotropic constitutive model, and the yielding stage is simulated employing the stiffness degradation method. The applicability of the honeycomb element is investigated in uneven squeezing ground, and the optimal design size is determined. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations are performed to investigate the mechanical behavior of nanotwinned NiCo-based alloys containing coherent L12 nano-precipitates at different temperatures, as well as the interactions between the dislocations and nano-precipitates within the nanotwins. The simulation results demonstrate that both the yield stress and flow stress in the nanotwinned NiCo-based alloys with nano-precipitates decrease as the temperature rises, because the higher temperatures lead to the generation of more defects during yielding and lower dislocation density during plastic deformation. Moreover, the coherent L12 phase exhibits excellent thermal stability, which enables the hinderance of dislocation motion at elevated temperatures via the wrapping and cutting mechanisms of dislocations. The synergistic effect of nanotwins and nano-precipitates results in more significant strengthening behavior in the nanotwinned NiCo-based alloys under high temperatures. In addition, the high-temperature mechanical behavior of nanotwinned NiCo-based alloys with nano-precipitates is sensitive to the size and volume fraction of the microstructures. These findings could be helpful for the design of nanotwins and nano-precipitates to improve the high-temperature mechanical properties of NiCo-based alloys. [ABSTRACT FROM AUTHOR]

It is well recognised that the rheology of an interstitial fluid has profound effects on debris flow dynamics. Existing design guidelines for multiple resisting barriers, however, do not consider the rheological behaviour of debris flows explicitly while estimating barrier spacing. A modified overflow equation is proposed, considering an improved overflow trajectory and a new yield stress-based velocity attenuation model, to estimate the overflow distance in two-phase flows. This study experimentally investigates the effects of yield stress of an interstitial fluid on the impact behaviour of two-phase flows with similar Froude numbers against dual-rigid barriers. The flow composition is varied to model a wide range of natural flows based on dimensionless yield stress. The results reveal that the hydrodynamic impact coefficient increases with increasing dimensionless yield stress and exceeds the existing international design guidelines by more than 13%. The existing guidelines underestimate the overflow distance by up to 115%. The modified formulation is verified and conservatively predicts overflow distance for water floods to debris flows. It is recommended that the dimensionless yield stress of interstitial fluid together with Froude number should be used to characterise the impact and overflow dynamics of two-phase flow for a conservative design of dual barriers. [ABSTRACT FROM AUTHOR]

In this work, the rheological properties of four multi-wall carbon nanotubes (MWCNTs)/polyethylene (PE) composites containing 1 wt.% (mPEC1), 3 wt.% (mPEC3), 5 wt.% (mPEC5), and 10 wt.% (mPEC10) MWCNTs prepared by the masterbatch method were investigated and compared with those of the pure PE. The rheological investigation includes strain sweeping, frequency sweeping, stress relaxation behavior, yield stress, characteristic relaxation time, temperature effect on linear viscoelastic behavior, and gel behavior. It is mainly found that (1) the MWCNTs-MWCNTs interaction resulting in MWCNTs network structure in the PE matrix and the MWCNTs-PE interfacial interaction increase the storage and loss moduli of the MWCNTs/PE composite in comparison with those of pure PE; (2) the time-temperature equivalence principle is applicable only for pure PE and mPEC1; (3) for gel behavior of MWCNTs/PE composite at 160–180 °C, the φ g value decreases with the increase of temperature and the highest S g value is obtained at 170 °C. [ABSTRACT FROM AUTHOR]

Copyright of Acta Materiae Compositae Sinica is the property of Acta Materiea Compositae Sinica Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Red clay is widely used in engineering projects; it is characterized by high moisture content, high plasticity, large porosity, high strength and low compressibility. The engineering properties and deformation modelling of red clay in Guiyang differ significantly from those of ordinary soils. Consequently, it is essential to conduct a detailed study of the stress–strain relationship of red clay in order to obtain accurate engineering parameters. Hence, a series of unconsolidated undrained triaxial compression tests (UU) was conducted on red clay in Guiyang under different water contents and confining pressures. The test results show that the stress–strain curve of the clay undergoes three stages: elastic deformation, plastic yielding and stress reduction after failure. After reaching peak deviatoric stress, the deviatoric stress decreases gradually and stabilizes, showing noticeable strain-softening characteristics. The non-linear model from the Nanjing Hydraulic Research Institute (NHRI) was introduced for fitting and obtaining relevant parameters. Then, based on the FLAC3D platform, numerical simulation was carried out on a standard soil sample. The research results show that the calculated curve from the non-linear model fits the experimental curve quite well, and the numerical test curve also agrees with it. This indicates that the non-linear model from NHRI can effectively reflect the strain-softening behaviour of clay and is highly applicable to Guiyang red clay. [ABSTRACT FROM AUTHOR]

The production of raw-crushed wind-turbine blade (RCWTB) and its addition to conventionally designed self-compacting Concrete (SCC) enable us to provide a second life to wind-turbine blades. However, SCC containing RCWTB must show proper fresh behavior, an aspect evaluated in this paper both experimentally and through simulations based on computational fluid dynamics (CFD) for RCWTB additions up to 3.0% by volume. In experimental terms, RCWTB reduced the flowability and passing ability of SCC, and slowed SCC flow, although the performance of SCC with 1.5% RCWTB was adequate under free-flow conditions. In terms of modeling, RCWTB did not impact yield stress and increased plastic viscosity. CFD modeling under free flow, regardless of the presence or not of obstacles simulating concrete reinforcement, was successful, especially in the long term. Nevertheless, the modeling of the passing ability was not accurate; precision could be improved by simulating the effect of the individual GFRP fibers within the SCC flow. Finally, the mechanical properties of SCC were negatively impacted by RCWTB, the stitching effect of the GFRP fibers not being effective in an SCC with a conventional design. A specific SCC design when adding RCWTB is therefore needed to advance in the use of this waste in this concrete type. [ABSTRACT FROM AUTHOR]

In the implementation process of carbon capture and storage (CCS), the geomechanical problems arising from the cyclic injection of carbon dioxide into the formation cannot be ignored. To clarify the influence of cyclic loading on the geomechanics properties of reservoir rocks, cyclic loading tests were carried out on rocks in sandstone reservoirs with the RTR‐2000 Rock Mechanics Test System, and the evolution of compressive strength, elastic modulus, and Poisson's ratio parameters was analyzed, which revealed the law of the geomechanical deterioration and damage evolution of sandstone reservoirs under cyclic loading. The results show that under the same cyclic load, when the number of cycles is increased to a certain degree, the influence on the peak strength is small. As the number of cycles increases, the modulus of elasticity of rock appears to be increasing and then decreasing, whereas a rapid increase in Poisson's ratio and a slow increase in Poisson's ratio occur with the increase in the number of cycles. Under the same number of cycles, the peak strength of the core gradually decreased with the increase of the maximum cyclic stress. When the cyclic load was smaller than the yield stress of the core, the effect of cyclic loading on the strength of the core was small, and when the cyclic load was larger than the yield stress, the effect of cyclic loading on the strength increased significantly. With the increase of cyclic load, the modulus of elasticity showed a tendency to increase and then decrease, and Poisson's ratio had a tendency of decreasing and the overall degree of change was small. [ABSTRACT FROM AUTHOR]

This study demonstrates a high‐throughput fabrication of fiber interlayers for proton exchange membranes based on poly(pentafluorostyrene) (PPFSt) and its aminated derivatives. The fibers are produced by electrospinning, where the parameters are carefully screened. The controlled parameters are solvent composition, weight percentage, voltage, flow rate, and temperature, controlled with a self‐designed heating jacket. The parameters are iterated toward optimized fiber structure and maximum output. The yielded fibers are infiltrated with Nafion and sulfonated polymer from bisphenol AF and decafluorobiphenyl (SFS001) by spray‐coating and doctor blading to obtain the fiber‐reinforced proton exchange membranes. Tensile tests reveal a higher Young's modulus and yield stress than pure Nafion. Here, the basicity of the aminated PPFSt fibers correlates with the Young's modulus due to improved acid‐base interactions between amine groups and sulfonic acid. The acid‐base interactions influence the composite membrane's proton conductivity, varying from 23 mS cm−1 for strongly alkaline fibers to 69 mS cm−1 for non‐basic fibers. These findings can be transferred to fabricating fiber reinforcements beyond routinely used poly(benzimidazoles). [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The root architecture, more seminal roots, and Deeper roots help the plants to uptake the resources from the deeper soil layer to ensure better growth. The Gibberellic acid-sensitive (GA-sensitive) Rht genes are well known for increasing drought tolerance in wheat. Much work has been performed on the effect of these genes on the plant agronomic traits and little work has been done on the effect of Rht genes on seminal roots and root architecture. This study was designed to evaluate 200 wheat genotypes under normal and osmotic stress. The genotypes were sown in the solution culture and laid under CRD factorial arrangement with three replications and two factors i.e., genotypes and treatments viz. normal and osmotic stress (20% PEG-6000) applied one week after germination. The data was recorded for the root traits. Results demonstrated that out of 200 genotypes, the GA-sensitive Rht13 gene was amplified in 21 genotypes with a fragment length of 1089 bp. In comparison, the GA-insensitive Rht1 gene was amplified in 24 genotypes with a band size of 228 bp. From 200 wheat genotypes, 122 genotypes produced 5 seminal roots, 4 genotypes 4 seminal roots, and 74 genotypes 3 seminal roots. The genotypes G-3 (EBW11TALL#1/WESTONIA-Rht5//QUAIU#1), G-6 (EBW01TALL#1/SILVERSTAR-Rht13B//ROLF07) and G-8 (EBW01TALL#1/SILVERSTAR-Rht13B//NAVJ07) produced 5 seminal roots and have longer coleoptile (> 4.0 cm), root (> 11.0 cm) and shoot (> 17 cm) under normal and osmotic stress. Furthermore, Ujala 16, Galaxy-13, and Fareed-06 produced 3 seminal roots and have short coleoptile (< 3 cm), root (< 9.0 cm) and shoot (< 10.0 cm). These results showed that the genotypes showing the presence of GA-sensitive Rht genes produced a greater number of seminal roots, increased root/shoot growth, and osmotic stress tolerance compared to the genotypes having GA-insensitive Rht genes. Thus, the Rht13 gene improved the root architecture which will help to uptake the nutrients from deeper soil layers. Utilization of Rht13 in wheat breeding has the potential to improve osmotic stress tolerance in wheat. [ABSTRACT FROM AUTHOR]

This paper presents an overview of recent works on microscale mechanical and other properties of silicon nitride (Si 3 N 4) determined by microcantilever bending tests and their relationships with the processing and microstructures. We first focus on deformation behaviors and fracture strength of Si 3 N 4 single crystals. β-Si 3 N 4 single crystals are plastically deformed at room temperature under high bending stress, and the yield stress depends on the crystal orientation. The critical resolved share stress of the primary slip system is determined to be below 1.5 GPa from the yield stress. Next, we address microscale mechanical properties of Si 3 N 4 polycrystalline ceramics. Emphasis is placed on their grain-boundary strength or toughness in conjunction with intergranular glassy film (IGF) which is determined by processing parameters such as sintering additives. Assessment is made on two cases of fractures at the IGF-grain interface and that within the IGF, and in each of the cases, effects of rare earth oxide additives are discussed. In Si 3 N 4 ceramics doped with Al 2 O 3 , β-SiAlON layer forming on β-Si 3 N 4 grains enhances the microscale grain-boundary strength. Finally, we shed light on microscale property-degradation behaviors of Si 3 N 4 ceramics, including the deterioration due to the contact with molten Al and the corrosion in sulfuric acid solution. The variation of the microscale properties appears in very short periods compared to the macroscale approaches, demonstrating the advantage in terms of rapid assessment of time-dependent degradation behaviors. [ABSTRACT FROM AUTHOR]