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At the line of triple contact of an elastic body with two immiscible fluids, the body is subjected to a force concentrated on this line, the fluid–fluid surface tension. In the simple case of a semi-infinite body, limited by a plane, a straight contact line on this plane, and a fluid–fluid surface tension normal to the plane, the classical elastic solution leads to an infinite displacement at the contact line and an infinite elastic energy. By taking into account the body–fluid surface tension (i.e., isotropic surface stress) and applying Kolosov's approach of plane strain elasticity, we present a new and simple expression of the solution concerning the semi-infinite body, which gives a finite displacement and a ridge at the contact line, and finite elastic energy. A detailed description of the displacements, strains, and stresses in the neighborhood of the contact line is given. This solution also shows that Green's formulae, in the volume and on the surfaces, are valid (these formulae play a central role in the theory). [ABSTRACT FROM AUTHOR]

Coarse-grained models have emerged as valuable tools to simulate long DNA molecules while maintaining computational efficiency. These models aim at preserving interactions among coarse-grained variables in a manner that mirrors the underlying atomistic description. We explore here a method for testing coarse-grained vs all-atom models using stiffness matrices in Fourier space (q-stiffnesses), which are particularly suited to probe DNA elasticity at different length scales. We focus on a class of coarse-grained rigid base DNA models known as cgDNA and its most recent version, cgDNA+. Our analysis shows that while cgDNA+ closely follows the q-stiffnesses of the all-atom model, the original cgDNA shows some deviations for twist and bending variables, which are rather strong in the q → 0 (long length scale) limit. The consequence is that while both cgDNA and cgDNA+ give a suitable description of local elastic behavior, the former misses some effects that manifest themselves at longer length scales. In particular, cgDNA performs poorly on twist stiffness, with a value much lower than expected for long DNA molecules. Conversely, the all-atom and cgDNA+ twist are strongly length scale dependent: DNA is torsionally soft at a few base pair distances but becomes more rigid at distances of a few dozen base pairs. Our analysis shows that the bending persistence length in all-atom and cgDNA+ is somewhat overestimated. [ABSTRACT FROM AUTHOR]

The thermal transport and elastic properties of materials are often measured using the laser-induced transient grating spectroscopy (TGS) technique. The analysis of the TGS signal usually involves fitting well-known expressions, derived assuming the limiting cases of opaque or transparent materials, to the measured data. In this paper, the system of thermoelastic equations is analytically solved for an isotropic homogeneous material assuming finite laser penetration depth, which is an important consideration when the penetration depth is on the order of the acoustic wavelength. The need to use such a solution is discussed and compared to the expression for opaque material. The solution is benchmarked against TGS signal measured on single-crystal silicon with {100} surface orientation and is found to significantly improve the accuracy of the calculated thermal diffusivity as compared to using the expression for opaque material. [ABSTRACT FROM AUTHOR]

Constitutive models are essential for describing the mechanical behavior of materials under high temperatures and pressures, among which the Steinberg–Guinan (SG) model is widely adopted. Recent work has discovered a peculiar dual anomaly of compression-induced softening and heating-induced hardening in the elasticity of compressed vanadium [Phys. Rev. B 104, 134102 (2021)], which is beyond the capability of the SG model to describe. In this work, a modified SG elasticity constitutive model is proposed to embody such an anomalous behavior. Elemental vanadium is considered as an example to demonstrate the effectiveness of this improved model in describing the dual anomalies of elasticity. This new SG elasticity model can also be applied to other materials that present an irregular variation in the mechanical elasticity and are important to faithfully model and simulate the mechanical response of materials under extreme conditions. [ABSTRACT FROM AUTHOR]

Biological lipid membranes are generally asymmetric, not only with respect to the composition of the two membrane leaflets but also with respect to the state of mechanical stress on the two sides. Computer simulations of such asymmetric membranes pose unique challenges with respect to the choice of boundary conditions and ensemble in which such simulations are to be carried out. Here, we demonstrate an alternative to the usual choice of fully periodic boundary conditions: The membrane is only periodic in one direction, with free edges running parallel to the single direction of periodicity. In order to maintain bilayer asymmetry under these conditions, nanoscale "sticky tapes" are adhered to the membrane edges in order to prevent lipid flip-flop across the otherwise open edge. In such semi-periodic simulations, the bilayer is free to choose both its area and mean curvature, allowing for minimization of the bilayer elastic free energy. We implement these principles in a highly coarse-grained model and show how even the simplest examples of such simulations can reveal useful membrane elastic properties, such as the location of the monolayer neutral surface. [ABSTRACT FROM AUTHOR]

We present results of resonant ultrasound spectroscopy (RUS) measurements applied to granular high explosive materials at different bulk pressing densities and degree of thermal conditioning. The material chosen in this study is a ubiquitously used explosive material known as pentaerythritol tetranitrate (PETN), which is used commercially in civil and defense applications both as a binderized plastic bonded explosive material and an unbinderized neat material. However, changes in granular PETN bulk elastic properties due to thermal conditioning, which could have implications for better understanding environmental aging-related effects, have not been well studied even though it is believed that elasticity may play an important role in explosive material initiation mechanisms. Furthermore, monitoring elastic property changes in granular explosive pressings has not yet been demonstrated using RUS, which is an appealing non-destructive characterization tool that requires only dry point contact with the explosive material. To this end, we report the first study using RUS to quantify the elastic properties of binderized and neat PETN pressings as well as to quantify changes in elastic properties as a function of both thermal conditioning and bulk pressing density. Elastic stiffness coefficients, sometimes more commonly referred to as elastic constants, calculated from the RUS measurements on the different PETN-based materials show a significant increase for the post-conditioned samples compared to the pre-conditioned samples. This trend of increasing elastic properties with thermal conditioning was consistent for different density pressings, different thermal exposure conditions, and even different neat PETN pressings of differing average crystal sizes and/or specific surface areas. [ABSTRACT FROM AUTHOR]

Owing to magnetoelastic coupling, surface acoustic waves (SAWs) may be scattered resonantly by magnetic elements, such as nickel stripes. The scattering may be further enhanced via the Borrmann effect when the elements are organized into an array that matches the acoustic wavelength. We use finite-element modeling to consider single- and double-layer stripes patterned on top of a lithium niobate surface that carries Love surface waves. We do observe enhancement in the coupling for single-layer stripes, but only for Gilbert damping below its realistic value. For double-layered stripes, a weak yet clear and distinct signature of Bragg reflection is identified far away from the acoustic band edge, even for a realistic damping value. Double-layered stripes also offer better magnetic tunability when their magnetic period is different from the periodicity of elastic properties of the structure because of staggered magnetization patterns. The results pave the way for the design of magnetoacoustic metamaterials with an enhanced coupling between propagating SAWs and local magnetic resonances and for the development of reconfigurable SAW-based circuitry. [ABSTRACT FROM AUTHOR]

Low-crosslinked polymer networks have recently been found to behave auxetically when subjected to small tensions, that is, their Poisson's ratio ν becomes negative. In addition, for specific state points, numerical simulations revealed that diamond-like networks reach the limit of mechanical stability, exhibiting values of ν = −1, a condition that we define as hyper-auxeticity. This behavior is interesting per se for its consequences in materials science but is also appealing for fundamental physics because the mechanical instability is accompanied by evidence of criticality. In this work, we deepen our understanding of this phenomenon by performing a large set of equilibrium and stress–strain simulations in combination with phenomenological elasticity theory. The two approaches are found to be in good agreement, confirming the above results. We also extend our investigations to disordered polymer networks and find that the hyper-auxetic behavior also holds in this case, still manifesting a similar critical-like behavior as in the diamond one. Finally, we highlight the role of the number density, which is found to be a relevant control parameter determining the elastic properties of the system. The validity of the results under disordered conditions paves the way for an experimental investigation of this phenomenon in real systems, such as hydrogels. [ABSTRACT FROM AUTHOR]

A review of the structural, elastic, and thermodynamic properties of cubic and hexagonal ScxAl1−xN crystals over the range of possible random alloys is provided. Based on measured and simulated lattice and internal cell parameters of NaCl (B1), CsCl (B2), and α-ZnS (B3) type cubic ScxAl1−xN lattices as well as of β-ZnS (B4), lh-MgO (Bk), and NiAs (B81) type hexagonal ScxAl1−xN crystals, their atomic positions, distances to nearest neighbor atoms, geometric dimensions of crystal cells, mass density, as well as their average bond length and bond angles are presented in dependence on the alloy composition. The understanding gained about the crystal lattices is used to provide a model for the transitions from the β-ZnS to the lh-MgO or NaCl lattice induced by the alloying of AlN with ScN. Based on published data sets of stiffness coefficients, the compliance coefficients, Young's modulus, shear modulus, Poisson's ratio, compressibility, and the sound velocities are presented in relation to the orientation of representative crystal planes and axes for rock salt, layered hexagonal, and wurtzite ScxAl1−xN crystals. Particular attention is paid to the directional anisotropies of elastic properties of the different crystal lattices if Sc atoms substitute an increasing number of Al atoms. Based on sound velocities determined, an overview of the fundamental thermodynamic properties of cubic and hexagonal ScxAl1−xN alloys is provided, such as the Debye temperature, heat capacity, minimum heat conduction, and melting temperature. [ABSTRACT FROM AUTHOR]

We employed high-pressure Brillouin scattering to study the pressure dependencies of acoustic modes of glycerol up to 14 GPa at 300 K. We observed longitudinal acoustic velocities and transverse acoustic velocities for the first time from 5 to 14 GPa. The results allow the determination of a complete set of elastic properties and an accurate determination of the pressure–volume (P–V) equation of state (EOS). EOS parameters, K0 = 14.9 ± 1.8 GPa and K′0 = 5.6 ± 0.5, were determined from fits to the data from ambient pressure to 14 GPa. Direct volume measurements of the P–V EOS are consistent with those determined by Brillouin scattering. A deviation from a Cauchy-like relationship for elastic properties was observed, and the pressure dependencies of the photoelastic constants and relaxation times were documented from 5 to 14 GPa. These results have broad implications for glass-forming liquids, viscoelastic theory, and mode coupling theory. [ABSTRACT FROM AUTHOR]

This paper presents results of a comprehensive study from first principles into the properties of Ni, Pd, Rh, and Ir crystals under pressure. We calculated elastic constants, phonon spectra, isotherms, Hugoniots, sound velocities, relative structural stability, and phase diagrams. It is shown that in nickel and palladium under high pressures (>0.14 TPa) and temperatures (>4 kK), the body-centered cubic structure is thermodynamically most stable than of the face-centered cubic one. Calculated results suggest that nickel under Earth-core conditions (P ∼ 0.3 TPa, T ∼ 6 kK) have a bcc structure. No structural changes were found to occur in Rh and Ir under pressures to 1 TPa at least. This paper also provides estimations for the pressure and temperature at which the metals of interest begin to melt under shock compression. [ABSTRACT FROM AUTHOR]

The research presented in the paper concerns the elastic properties of struvite. The article combines theoretical and experimental research. Experimental studies were carried out on struvite single crystals grown in sodium metasilicate gel by single diffusion. This unique method leads to obtaining crystals of sufficiently large size to conduct, for the first time, experimental measurement of elastic properties of monocrystalline struvite. Using the nanoindentation method, the Ez = 29.1 ± 0.7 GPa value of the component of Young's modulus was determined for a struvite single crystal. In addition, the elastic constants C11, C22, and C33 were determined using micro-Brillouin spectroscopy. Theoretical calculations of the abovementioned properties have been carried out by employing density functional theory methods. Scaling of the theoretical elastic constants leads to obtaining good agreement with the experimental values. Values of the Ex and Ey components of the Young's modulus, not available from the experimental nanoindentation technique, have been determined theoretically as 23 GPa and 27 GPa, respectively. Differences in the values of elastic components and Young's modulus components are related to the layered crystal structure of struvite and directional character of the hydrogen-bonding pattern. [ABSTRACT FROM AUTHOR]

This paper presents a theoretical study of a graded piezoelectric composite consisting of an infinitely long graded radially polarized piezoelectric cylinder embedded in an isotropic elastic non-piezoelectric matrix, under an external strain field. The physical properties of the graded cylindrical inclusion have a power-law profile with respect to the cylindrical radial variable. Using the variable separation method, closed-form solutions for the elastic displacement and electrical field in the entire composite regions are derived from the governing equation. The effective elastic and piezoelectric properties of the graded piezoelectric composite are formulated and discussed. The study reveals a vanishing mechanism of effective piezoelectric response in the graded radially polarized cylindrical piezoelectric composite. In addition, the paper derives the effective elastic formulas of the graded cylindrical elastic composites for the purely elastic problem and discusses the effects of graded property parameters on the effective elastic properties. [ABSTRACT FROM AUTHOR]

Objectives: The whole-body vibration (WBV) effects on muscle strength show inconsistent results. Moreover, there is no study about the WBV effect on stiffness, elasticity, and muscle strength. Therefore, the study aimed to examine the effect of WBV exposure with static squat posture on the stiffness, elasticity, and strength of the lower-limb extensor muscles. Material and methods: Forty healthy untrained young adults were divided into WBV and control groups. The experimental group received WBV exposure on 2 nonconsecutive days of the week, for 6 weeks. The MyotonPRO device was used for the assessment of the knee extensor and the ankle dorsiflexors' stiffness and elasticity. Isometric muscle strength was evaluated with a hand-held dynamometer. All measurements were done by the same assessor at baseline, and the following 6 weeks. Results: Significant group-by-time interactions were found for the elasticity scores of the right (d = 0.84, P = .01) and left (d = 0.77, P = .02) ankle dorsiflexors. Similar to the elasticity measurements, significant group-by-time interactions were observed in the muscle strength scores of the right (d = 0.45, P = .046) and left (d = 1.25, P < .001) ankle dorsiflexors. No significant effects were observed in any of the evaluated muscle stiffness measurements (P > .05), and there was no significant group-by-time interaction in knee-extensor muscle strength and elasticity scores (P > .05). Conclusions: The study results indicate that if the ankle dorsiflexor strength and elasticity are desired to be increased, the 6-week WBV exposure in a static squat posture can be used in healthy individuals. [ABSTRACT FROM AUTHOR]

We present structural, electronic, magnetic, elastic and transport properties of tetragonal Mn2PtSn (MPS) bulk material in stannite (ST) phase, we will use a FP-LAPW method based on DFT under GGA, TB-mBJ and GGA+U as implemented in the WIEN2k code. From the ferromagnetic state, band structure (spin-down/spin-up channel) calculations reveal an indirect bandgap/zero-bandgap. Mn2PtSn shows inverse tetragonal crystal structures with ferromagnetic spin order at zero temperature. The elastic stability criterion shows that the MPS crystal satisfies the mechanical stability under applied at 0 GPa. The related mechanical properties such as bulk modulus (B), shear modulus (G), Young's modulus (E), and Poisson's ratio (ν) are also studied for polycrystalline of MPS; the calculated B/G value (B/ G = 2. 9 6) shows that MPS behaves in a ductile manner. Hence, this study of transport properties suggests their potential thermoelectric applications at high temperatures. To our knowledge, the results obtained show that this ternary alloy is advantageous for materials employed in spintronic devices. [ABSTRACT FROM AUTHOR]

Elastic properties of Si0.95H0.21O2 with hydrogarnet substitution (4H+ = Si4+) across the post‐stishovite transition (28–42 GPa) are determined up to 70 GPa using ab initio calculations and a pseudo‐proper type Landau model. At 28 GPa, elastic coefficients C11 and C12 converge, and the average shear and compressional velocity (VS and VP) decrease by a maximum of 25.5% and 5.2%, respectively. Hydrogarnet substitution reduces ambient elastic moduli and sound velocities, and shifts shear softening to lower pressure. 2%–13% Si0.95H0.21O2 may cause a VS anomaly of −0.5% to −2.6% at 700–820 km depth, explaining low VS layers beneath North America and the European Alps. Additionally, 20 vol % SiO2 in subducted basalt, with decreasing water content from 3.2 wt% to zero, could cause a VS anomaly of up to −7(4) % from 700 to 1,900 km depth, aligning with seismic scatterers identified in some subduction regions. Plain Language Summary: Our study explores the elasticity of stishovite and post‐stishovite (high‐pressure forms of SiO2) with 3.2 wt% water (Si0.95H0.21O2) up to 70 GPa using theoretical methods. During the transition from stishovite to post‐stishovite (28–42 GPa), shear softening occurs, and shear wave speed (VS) decreases by up to 25.5%. The direct hydrogen substitution for silicon can lower the ambient seismic wave speed and shift shear softening to lower pressure. A small amount of Si0.95H0.21O2, when present in the top lower mantle, could display low VS under North America and the European Alps, as identified by seismologists. Also, subducted mid‐ocean ridge basalt with lower H2O content in SiO2 from 700 to 1,900 km depth might account for seismically observed negative VS anomalies in certain subduction regions. Key Points: Elasticity of Si0.95H0.21O2 with 4H+ = Si4+ across the post‐stishovite transition is studied by ab initio calculation and Landau theoryElastic coefficient C11 converges with C12 and shear wave velocity VS decreases by 25.5% at 28 GPa in Si0.95H0.21O2Low VS layers and small‐scale VS anomalies in the shallow lower mantle could be caused by the post‐stishovite transition in hydrous SiO2 [ABSTRACT FROM AUTHOR]

In this study, analytical solutions were proposed to investigate the flexural creep behaviors of viscoelastic layered beams subjected to sustained loads. The viscoelastic properties of the laminar layer and the interlayer were considered. Based on exact elasticity theory and the Boltzmann superposition principle, viscoelastic analytical solutions were obtained. Comparative studies indicated that the present solution had better precision than the Euler–Bernoulli beam solution, especially for thick beams. In addition, the present solution had greater computational efficiency than the finite element solution because the latter involves the time discretization method. The influences of various parameters were analyzed in detail. [ABSTRACT FROM AUTHOR]

The innovative combination of additive manufacturing (AM) and continuous fiber‐reinforced polymer composites (CFRPCs) confers products with the dual advantages of integrated manufacturing and designability of properties, but lack an efficient and reliable method for property prediction. This study presents a materials informatics framework using reduced‐order models and machine learning (ML) to extract the structure–property (SP) linkages between microstructures and macroscopic elastic properties of AM‐CFRPCs. The initial step involves generating microstructural 2D cross‐sections and representative volume elements (RVEs) with random fiber and pore distributions based on the minimum potential method. Then, finite element (FE) calculations are performed on RVEs to obtain nine macroscopic elastic properties. Following that, the quantification and dimensionality reduction of the 2D cross‐sectional dataset are conducted separately using two‐point spatial correlations and principal component analysis (PCA). Finally, a Bayesian optimized composite kernel support vector regression (CK‐SVR) algorithm is used to effectively establish complex mapping relationships between the reduced‐order representations of the microstructures and the mechanical properties. Despite the reduced‐order dataset containing only 3–6 variables, the framework generates an interpretable model exhibiting excellent accuracy with all predicted R2 values surpassing 0.91. Therefore, this framework presents a prospective solution for expediting the design and optimization of AM‐CFRPCs. Highlights: A materials informatics scheme is proposed to predict the 9 elastic properties of AM‐CFRPCs.Microstructures are quantified and dimensionally reduced by two‐point statistics and PCA.SP linkages are established between 2D cross‐sections and 3D macromechanical properties.Modified CK‐SVR exhibits higher prediction accuracy compared to conventional models. [ABSTRACT FROM AUTHOR]

The heavy transition metal borides, carbides, and nitrides are still difficult to synthesize, and certain compositions are not even possible to stabilize. With the help of existing materials databases, we assemble 240 materials of chemical formula M 2 X, that we intend to investigate via density-functional theory (DFT). Our calculations demonstrate the stability of several novel compounds, which are highly likely to be synthesized in experiment, widening the potential applications as structural ceramics. The X site plays the primary role in determining the structural stability, with boron leading to many more stable ceramics than carbon and nitrogen. The chemical bonding is found to arise from a mixture of covalent bonding (M-X) and weak metallic bonding (M-M), which ensures varied elastic properties. Among the newly predicted materials, Tc 2 B ,Os 2 B , and Os 2 C are shown to be ultra-incompressible. A low shear modulus makes these systems prone to plasticity, which leads to an interesting coexistence of hardness and ductility for novel Os 2 B and Os 2 C , as well as existing Mo 2 B and Mo 2 C. Chemically, replacing 4 d with 5 d elements is shown to enhance bulk and shear moduli, which could be used for hardness engineering by selective doping. This report lays the foundations for further experimental research on the mechanical merits of the late transition metal borides, carbides, and nitrides of chemical formula M 2 X. [ABSTRACT FROM AUTHOR]

Phospholipid-coated microbubbles with a uniform acoustic response are a promising avenue for functional ultrasound sensing. A uniform acoustic response requires both a monodisperse size distribution and uniform viscoelastic shell properties. Monodisperse microbubbles can be produced in a microfluidic flow focusing device. Here, we investigate whether such monodisperse microbubbles have uniform viscoelastic shell properties and thereby a uniform "mono-acoustic" response. To this end, we visualized phase separation of the DSPC and DPPE-PEG5000 lipid shell components and measured the resonance curves of nearly 2000 single and freely floating microbubbles using a high-frequency acoustic scattering technique. The results demonstrate inhomogeneous phase-separated shell microdomains across the monodisperse bubble population, which may explain the measured inhomogeneous viscoelastic shell properties. The shell viscosity varied over an order of magnitude and the resonance frequency by a factor of two indicating both a variation in shell elasticity and in initial surface tension despite the relatively narrow size distribution. [ABSTRACT FROM AUTHOR]

Many population statistics describe the characteristics of populations within and among species. These are useful for describing population dynamics, understanding how environmental factors alter demographic patterns, testing hypotheses related to the evolution of life history characteristics and informing the effective management of populations.In this study, we propose a population statistic: the interstage flow. The interstage flow is defined as the product of the element in the ith row, the jth column of the population projection matrix and the jth element of the normalized stable stage distribution.The sum of the interstage flow matrix elements is equal to the population growth rate (PGR), which is the dominant eigenvalue of the population projection matrix. The interstage flow matrix elements allow decomposition of PGR into component contributions made by transitions between developmental stages.We demonstrate the utility of interstage flow matrices using matrix population models from the COMPADRE plant matrix database. We compared interstage flows among four life history/functional groups (FGs) (semelparous herbs, iteroparous herbs, shrubs and trees) and described how PGR reflected individual transitions related to stasis, fecundity and growth. We found that the individual flows are different among FGs.Synthesis. The proposed population statistic, the interstage flow matrix, describes the contribution of individual developmental stage transitions to the PGR. The flow of individuals between developmental stages differs in distinctive ways among different life histories and FGs. The interstage flow matrix is a valuable statistic for describing these differences. [ABSTRACT FROM AUTHOR]

Objective: We aimed to investigate changes in the elastic properties of levator ani muscle (LAM) and external anal sphincter (EAS) during pregnancy using shear wave elastography (SWE). Our secondary objective was to examine the association between the elastic properties of pelvic floor muscles (PFM) and perineal tears at childbirth. Methods: This was a prospective monocentric study, including nulliparous women. Three visits were planned (14–18, 24–28, and 34–38 weeks) with a SWE assessment of the LAM and EAS at rest and during Valsalva maneuver. Then, we collected data about the delivery's characteristics. Assessments were performed using an Aixplorer V12® device (SL 18–5 linear probe) using a transperineal approach, reporting the shear modulus in kPa. We looked for changes in PFM's elastic properties during pregnancy using one-way ANOVA for repeated measures. We compared the mean shear modulus in late pregnancy for each muscle and condition between women with an intact perineum at delivery and those with a perineal tear using Student's t test. Results: Forty-seven women were considered. Forty-five women had vaginal delivery of which 38 (84.4%) had perineal tears. We did not report any significant changes in the elastic properties of PFM during pregnancy. Women with an intact perineum at delivery had a stiffer EAS at Valsalva maneuver in late pregnancy (27.0 kPa vs. 18.2 kPa; p < 0.005). Conclusions: There were no significant changes in the elastic properties of the PFM in pregnancy. Stiffer EAS in late pregnancy appears to be associated with a lower incidence of perineal tears. [ABSTRACT FROM AUTHOR]

The first high damage resistant ultra-high temperature ceramic ScB 2 C 2 with excellent hydrolysis resistance was successfully prepared through boron carbon thermal reduction and hot pressing sintering using Sc 2 O 3 , B 4 C and graphite as raw materials. The Vickers hardness, flexural strength, fracture toughness, Young's modulus, shear modulus, bulk modulus and Poisson's ratio of as-prepared ScB 2 C 2 ceramic are 6.0 ± 0.2 GPa, 246 ± 17 MPa, 4.11 ± 0.18 MPa·m1/2, 240 GPa, 101 GPa, 127 GPa and 0.18, respectively. In the a - b plane (B 2 C 2 sheet) and along the c -axis direction, ScB 2 C 2 exhibits extremely strong anisotropy of chemical bonds and elastic properties. The high residual strength, damage tolerance factor D t and fracture toughness to strength ratio K Ic /σ f indicates that ScB 2 C 2 has excellent damage tolerance. In addition, ScB 2 C 2 displayed remarkable thermal shock resistance and hydrolysis resistance. These unique features endow ScB 2 C 2 with significant potential for future ultra-high temperature applications. [ABSTRACT FROM AUTHOR]

Novel engine fan blades are made of 3D woven composite materials and incorporate a protective metallic layer at the leading edge. The end-of-life of such structures involves complicated disassembly and recycling processes. In this paper, laser-shock is being investigated as an environmentally friendly disassembly method. In this context, symmetric laser-shock experiments that have been conducted in a previous work using a time delay between the shots have been proven successful for debonding initiation and propagation as they manage to effectively focus the tensile stress field developed by the shock waves at the bondline. In this paper, a numerical model simulating the symmetric laser-shock disassembly of titanium/CFRP specimens has been developed using the LS-Dyna explicit FE code. The aim is to give a deeper insight into the physical mechanisms and to optimize the experimental process. To simulate the behavior of the titanium part, the Johnson-Cook material model in combination with Grüneisen equation of state has been employed, while for the composite part a progressive damage material model incorporating high-strain rate effects has been used. The bondline between the two parts has been modeled using cohesive zone elements. To obtain tensile and shear elastic and strength properties at high strain rates for the composite damage model, tension and punch shear Split-Hopkinson Bar tests have been conducted. The numerical results correlate well with back-face velocity profiles obtained from single sided laser shock experiments and with debonding patterns in the adhesive, observed in electron microscopy images, induced by symmetrical laser shock experiments. After the validation, the numerical model has been used successfully to simulate a larger disassembly process composed of 16 consecutive shots. [ABSTRACT FROM AUTHOR]

Summary: The study examined the impact of untreated β‐glucan (UtβG) and ozonated β‐glucan (OzβG) on the characteristics of batter and gluten‐free eggless cake prepared using finger millet and flaxseed flour by encompassing a comprehensive analysis of physical, rheological, textural, morphological, sensory and nutritional properties. As the β‐glucan level increased, batter density and viscosity demonstrated an upward trend. The frequency sweep test revealed that β‐glucan altered the rheological parameters of batter, with the storage modulus (G′) surpassing the loss modulus (G″), indicating more elastic properties. The inclusion of OzβG resulted in improved physical characteristics and decreased the cake hardness, attributed to the formation of carboxyl and hydroxyl groups. Cakes incorporated with 1.5% OzβG had the highest overall acceptability score. Hence, this study sheds light on the utilisation of untreated and modified oat β‐glucan in the development of gluten‐free eggless cake, potentially aiding the bakery industry in meeting the rising demands for such products. [ABSTRACT FROM AUTHOR]

In this work, the WIEN2k computer code was used to investigate the structural, elastic, electronic, magnetic, optical, thermoelectric, and dynamic properties of the CoCrTe half-Heusler (HH) compound. The Full-Potential Linearized Augmented Plane Wave method and Density Functional Theory were both used in this work. To further understand the electronic band gap, we used the modified Becke Johnson exchange–correlation functional method. We investigated the CoCrTe HH compound's electronic characteristics using density of states plots and band structure plots. By calculating magnetic moments and observing the behavior of spin-polarized electronic states, we also investigated the magnetic properties. Additionally, the CoCrTe HH compound's elastic properties were identified. These characteristics, including stiffness, resilience, and overall stability, offer crucial information about how the material reacts to mechanical deformation. Properties studied emphasized that the compound is metallic, and it appears as a good thermoelectric material. Finally, the compound's dynamic properties show that it is dynamically stable as well as mechanically. [ABSTRACT FROM AUTHOR]

The melt quenching technique was used to prepare zinc tellurite glasses with composition of [(TeO2)0.7 (ZnO)0.3]1-x [Sm2O3]x, where x is the molar fraction. The glasses were synthesized at various x values of 0.01, 0.02, 0.03, 0.04, and 0.05. Xray diffraction patterns depict the absence of distinct absorption peaks, indicating its amorphous nature. The shear and longitudinal velocities of the samples were measured using 5 MHz of frequency at room temperature. Physical properties such as density ( ρ) , and molar volume ( V m) increases from 5.142 to 5.324 g/cm3 and 27.412 to 27.590 cm3/mol. Variations in ultrasonic velocity, elastic moduli, Debye temperature ( θ D ), Softening temperature ( T S ) and Poisson's ratio (σ) were discussed and correlated with the composition of the glass samples. Additionally, elastic moduli and Poisson's ratio were compared with the theoretically measured data using the four theoretical elastic models of Makishima and Mackenzie, Rocherulle, Bond compression and Ring Deformation models. The Judd-Offelt parameters ( Ω 2 , Ω 4 and Ω 6 ) are obtained using Judd-Ofelt theory. To determine the possible applications of the synthesized glasses, the spectroscopic parameters were calculated for each band: radiative transition probabilities [ A MD / A ED ], branching ratio β R , spectroscopic quality factor ( Ω 4 / Ω 6 ), gain bandwidth (Δλeff × σp) and the optical gain (σp × τ). The obtained higher values of gain bandwidth, optical gain, branching ratio, spectroscopic quality factor (1.550) and the radiative transition probabilities show that the glasses prepared are appropriate for laser applications. [ABSTRACT FROM AUTHOR]

In this study, we have investigated a range of structural, elastic, electronic, optical, and thermoelectric properties of halide double perovskites Cs2BʹGeCl6 (Bʹ: Zn, Cd). Our analysis was conducted using the full potential linearized augmented plane wave (FP-LAPW) method with the generalized gradient approximation (GGA) and the modified Becke–Johnson (mBJ) potential. Structural parameters were determined through optimization and analytical schemes, allowing us to precisely define the crystal structure. Elastic properties, including elastic constants, shear modulus, Young's modulus, anisotropy factor, and Poisson's ratio, were calculated to assess the materials' mechanical characteristics. The electronic properties of these double perovskites reveal their semiconductor nature, characterized by an indirect energy band gap (Xv-Lc). Optical properties, including as the dielectric function, absorption coefficient, refractive index, extinction coefficient, reflectivity, electron energy loss, and optical conductivity, were computed across a photon energy range up to 13.0 eV to elucidate the optical response of the materials. Additionally, we predicted the thermoelectric properties of Cs2BʹGeCl6 (Bʹ: Zn, Cd) by calculating key thermoelectric coefficients, including the Seebeck coefficient and power factor. Our findings suggest the potential suitability of Cs2BʹGeCl6 (Bʹ: Zn, Cd) double perovskites for applications in photovoltaic and thermoelectric devices. [ABSTRACT FROM AUTHOR]

Recently, composite PVDF membranes with good performance have triggered enormous interest because of their great potential application. However, the uncertainty of mechanical properties limits their application. Herein, this paper reveals the elastic modulus properties of the loading angle between warp and tensile direction using the uni-axial tensile test of SH-1050P membrane textile. In addition, the bi-axial tensile test with different loading ratios was implemented. Both uni-axial and bi-axial ductile load-displacement/stress-strain curves are featured. It is the first to establish a relationship between the elastic modulus and the loading angle using a theoretical method based on the assumption that there is no slippage and crease between yarns and matric. Furthermore, simulations with different textile parameters were carried out to verify the theoretical results. The key finding is that the elastic modulus under uni-axial load can be divided into two stages, which are elasticity and plasticity. Both of which are proportional to the sine function applied to two times the loading angle. The Poisson's ratio of SH-1050P textile can be considered as a fixed value of 0.11. This conclusion can be extended to similar textiles. The outcome of this paper contributes to a deeper understanding of the PVDF memrane's mechanical behavior and presents a novel insight into its response to different loading conditions. [ABSTRACT FROM AUTHOR]

In this paper, we have studied the behaviour of two symmetric mode-III collinear cracks in a functionally graded material (FGM). The fundamental goal of this paper is to provide insight on the interaction of two cracks in FGMs with the strain gradient effect. To assess the influence of gradient elasticity, we have considered two key parameters ℓ and ℓ ′ , which describe the size scale effect caused by the underlying microstructure and are related to volumetric and surface strain energy, respectively. The crack boundary value problem have been solved by the approach involving Fourier transforms and the innovative hyper-singular integro-differential equation method, where the integral equation contains the two terms in integrals for the both cracks. A system of equations has been constructed by employing the Chebyshev polynomial expansion and then by choosing the suitable collocation points the system of equation have been solved. Our investigation involves the determination of stress intensity factors at both crack tips. These factors are vital for understanding the material's fracture behavior and structural integrity. Furthermore, we explore the variations in the displacement profile when the distance between the cracks is reduced to close proximity. This particular scenario is of significant interest as it provides insights into how the interaction between the cracks impacts the overall structural response. [ABSTRACT FROM AUTHOR]

Some arms of nanorobots display L-shaped structures. The transverse free bending vibration of an L-shaped cantilever nanobeam carrying a tip nanoparticle is investigated. Based on the nonlocal elasticity, the nonlocal parameter is introduced to capture the size effect of the mechanical behavior of the cantilever–mass system. The frequency equation is deduced analytically. Exact resonance frequencies of the L-shaped nanocantilever–mass system are numerically evaluated and compared with their corresponding values of the macro-scale L-shaped cantilever–mass system. The numerical results show that the nonlocal parameter declines the resonance frequencies. If removing the nonlocal parameter, our results reduce to the resonance frequencies of transverse bending vibration of L-shaped cantilevers with an attached tip mass. The effects of the nonlocal parameter, the ratio of the attached mass to the structure mass, the length ratio of two members of the L-shaped cantilever–mass system on the resonance frequencies are analyzed. [ABSTRACT FROM AUTHOR]

This study employs the Lur'e operator method to derive generalized solutions for orthorhombic quasicrystals, incorporating anisotropy factors as constraints. The solutions derived contain the Lekhnitskii-Hu-Nowacki and Elliott-Lodge solutions as special cases. The corresponding fundamental solutions or Green's functions within the infinite space are also derived, offering a comprehensive characterization of quasicrystal anisotropy. It is noteworthy that Green's functions in orthorhombic quasicrystals can be simplified to those in hexagonal quasicrystals or conventional orthorhombic crystals, with possible broad engineering applications. [ABSTRACT FROM AUTHOR]

In the present work, an atomistic scale investigation is done on crystalline silicon to understand the effect of crack depth from the loading (pulling) boundary on the critical near-tip state of stress. For various depths of embedded cracks, the near-tip stress field has been calculated at the critical state just before the crack propagation initiation. This atomistically calculated stress field is found to be quite close to those found using continuum linear elasticity. Thereafter, the critical stress intensity factor (SIF) is calculated for all cases by fitting the atomistically calculated normal stress over inverse square-rooted distance from the crack tip. It has been found that the closer the crack is located to the loading boundary (i.e., lesser depth), the lower is the (locally calculated) critical SIF. This implies that it is easier to initiate crack propagation when the crack is located closer to the loading boundary. The claim is also strengthened by a similar observation of (globally calculated) boundary stresses at the critical state just before crack propagation initiation. [ABSTRACT FROM AUTHOR]

Thin-walled cylindrical shell structures are revisited with the objective of increasing the axial load-carrying capacity. By using the postbuckling reserve of rectangular plates, polygonal shells are studied, which combines the response of a plate-like structure with a shell-like structure. These "plate-shells" are shown to be imperfection insensitive for a range of polygonal shell designs. Furthermore, their collapse load exceeds the corresponding load for a circular cylindrical shell. These results are a significant departure from the well-known imperfection sensitivity in the axial compressive response of cylindrical shells. [ABSTRACT FROM AUTHOR]

What are the historical origins of political fragmentation and unification? This study develops a Malthusian growth model with multiple states to explore interstate competition and the endogenous emergence of political fragmentation versus a unified empire. Our model features an agricultural society with citizens and rulers in a Malthusian environment in which the expansion of one state may come at the expense of another state, depending on the intensity of interstate competition captured by the elasticity of the land ratio with respect to the population ratio between states. If this elasticity is less than unity, then multiple states coexist. However, if this elasticity is equal to unity, then a unified empire emerges. Which state becomes the unified empire depends on its military power, agricultural productivity, and its rulers' preference for rent-seeking Leviathan taxation. We also discuss the historical relevance of these theoretical predictions in the Warring States period of ancient China. [ABSTRACT FROM AUTHOR]

Sustainable development and the preservation of the natural environment are two concepts that are becoming increasingly important in the construction sector, leading to a growing interest in the development of ecofriendly building solutions. In this regard, the use of waste polyethylene terephthalate (PET) bottles as a construction material is an interesting alternative that can help to reduce the environmental impact of the building activity at little or no cost, while providing a second life to a material that is one of the main sources of pollution. The present study analyses the mechanical behavior of PET bottles for their use as construction materials, carrying compression tests to assess the elastic properties of PET bottles filled with sand or plastic waste, both alone and embedded in a concrete matrix. In a second part of the study, a finite-element method model of an existing water tank built with PET bottles in Tanzania is developed and tested. The results obtained show the suitability of the composite bottle-and-concrete samples as a sustainable construction technique. Environmental sustainability is an increasingly important aspect in our society and all its productive sectors, and the construction industry is no exception. In this regard, diverse initiatives have been proposed to introduce waste polyethylene terephthalate (PET) bottles as a construction material, which provides three direct benefits: offering a low-cost construction material, reducing the consumption of new resources, and giving a second life to waste material that would otherwise end up in landfills or in the environment. However, to use these new sustainable materials in safety conditions, it is necessary to understand their mechanical and structural behavior and treat them with the same rigor as we treat conventional construction materials such as concrete or steel. In this sense, in the present study, a testing campaign is conducted to assess the compressive strength of PET bottles filled with sand or plastic, as well as their combined use with concrete to form walls in buildings or water tanks. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes exposes the body to a state of high blood sugar for a long time and causes varying degrees of hardening of the arteries, making it more prone to cardiovascular emergencies. Objective: The aim of the study was to explore the risk factors of early arterial stiffness in patients with type 2 diabetes mellitus (T2DM). Methods: A retrospective study was conducted on 316 T2DM patients without macroangiopathy in The First Hospital of Qinhuangdao. Early arterial stiffness was evaluated by brachial-ankle pulse wave velocity (baPWV). Results: Ninety patients (28.5%) had baPWV≥1800cm/s. baPWV showed positive correlation with systolic blood pressure (r=0.456, p<0.001), diastolic blood pressure (r=0.133, p=0.018), urine albumin-creatinine ratio (UACR) (r=0.232, p<0.001), neutrophil lymphocyte ratio (NLR) (r=0.185, p=0.001), and visceral fat area (r=0.139, p=0.014). In multiple linear regression analysis, systolic blood pressure (β=6.240, p<0.001), UACR (β=3.805, p=0.019), NLR (β=43.722, p=0.013), and visceral fat area (β=0.778, p=0.030) were significant independent predictors for baPWV. Conclusion: The decline of arterial elasticity was common in T2DM patients without macroangiopathy. Elevated blood pressure, microangiopathy, chronic inflammation, and visceral fat accumulation were the risk factors of early arterial stiffness in patients with T2DM. [ABSTRACT FROM AUTHOR]

Is it possible to design an architectured material or structure whose elastic energy is arbitrarily close to a specified continuous function? This is known to be possible in one dimension, up to an additive constant (Dixon et al., Bespoke extensional elasticity through helical lattice systems, Proc. R. Soc. A. (2019)). Here, we explore the situation in two dimensions. Given (1) a continuous energy function E (C) , defined for two-dimensional right Cauchy–Green deformation tensors C contained in some compact set and (2) a tolerance ϵ > 0 , can we construct a spring-node unit cell (of a lattice) whose energy is approximately E , up to an additive constant, with L ∞ -error no more than ϵ ? We show that the answer is yes for affine E s (i.e., for energies E that are quadratic in the deformation gradient), but that the general situation is more subtle and is related to the generalisation of Cauchy's relations to nonlinear elasticity. [ABSTRACT FROM AUTHOR]

In this paper, we investigate the influence of residual stress on the stability of a solid circular cylinder subject to axial extension. The nonlinear theory of elasticity is used to derive the equations governing the linearized incremental deformations superimposed on a known finitely deformed configuration. Specialized to the neo-Hookean model with residual stress, the bifurcation analysis results in an exact bifurcation condition for zero and periodic modes, based on the Stroh formalism. An expansion technique is adopted to treat singularities in the governing equations. We investigate three loading scenarios, specifically, gradual increase in axial stretch with constant residual stress and gradual increase in residual stress with fixed axial length or fixed axial force. In each case, the zero mode, corresponding to a localized bifurcation, occurs first. An explicit bifurcation condition for the zero mode is derived, which accounts for the effect of geometric dimensions, the residual stress, and the axial elongation on the stability of the solid cylinder. The critical values of the residual stress and the axial force for localized necking or bulging to occur are identified. In particular, we show that a reduction in residual stress delays the onset of localized necking. At constant values of pre-stretch, with 1. 5 < λ < 2. 10692 , localized necking occurs at a critical residual stress, whereas localized bulging occurs when λ > 2. 10692. We use the Maxwell equal-area rule to characterize the "two-phase" deformation consisting of necked and bulged regions. It is shown that the Maxwell values of stretch identify the radii of the two regions, which are connected by a transition zone that translates along the cylinder. At the completion of "two-phase" deformation, the stretch is again uniform. [ABSTRACT FROM AUTHOR]

Tissue susceptibility to histotripsy disintegration has been reported to depend on its elastic properties. This work was aimed at investigation of histotripsy efficiency for liquefaction of human hematomas, depending on their stiffness and degree of retraction over time (0–10 d). As an in vitro hematoma model, anticoagulated human blood samples (200 mL) were recalcified at different temperatures. In one set of samples, the shear modulus was measured by shear wave elastography during blood clotting at 10℃, 22℃ and 37℃, and then daily during further aging. The ultrastructure of the samples was analyzed daily with scanning electron microscopy (SEM). Another set of blood samples (50–200 mL) were recalcified at 37℃ for density and retraction measurements over aging and exposed to histotripsy at varying time points. Boiling histotripsy (2.5 ms pulses) and hybrid histotripsy (0.2 ms pulses) exposures (2 MHz, 1% dc, P +/ P –/ A s = 182/–27/207 MPa in situ) were used to produce either individual cigar-shaped or volumetric (0.8–3 mL) lesions in samples incubated for 3 h, 5 d and 10 d. The obtained lesions were sized, then the lysate aspirated under B-mode guidance was analyzed ultrastructurally and diluted in distilled water for sizing of residual fragments. It was found that clotting time decreased from 113 to 25 min with the increase in blood temperature from 10℃ to 37℃. The shear modulus increased to 0.53 ± 0.17 kPa during clotting and remained constant within 8 d of incubation at 2℃. Sample volumes decreased by 57% because of retraction within 10 d. SEM revealed significant echinocytosis but unchanged ultrastructure of the fibrin meshwork. Liquefaction rate and lesion dimensions produced with the same histotripsy protocols correlated with the increase in the degree of retraction and were lower in retracted samples versus freshly clotted samples. More than 80% of residual fibrin fragments after histotripsy treatment were shorter than 150 µm; the maximum length was 208 µm, allowing for unobstructed aspiration of the lysate with most clinically used needles. The results indicate that hematoma susceptibility to histotripsy liquefaction is not entirely determined by its stiffness, and correlates with the retraction degree. [ABSTRACT FROM AUTHOR]

In this paper, we present an improved dynamic analysis method to address plane elasticity problems. Distributed sources are employed in a boundary-free mesh-based approach known as Boundary Distributed Source (BDS). This method, which builds upon a modified Method of Fundamental Solutions (MFS), aims to eliminate singularities without the reliance on fictitious boundaries. Distributed sources are strategically positioned directly on the real boundary, centered over disks. The method's efficiency and simplicity are highlighted by its ability to operate without the need for precise data concerning adjacent points. The dual reciprocity method (DRM) is utilized to approximate the non-homogeneous inertial term. Furthermore, the present formulation investigates several factors that influence the convergence of the proposed method, including the number of collocation points, internal points, the radius of the circular disk, and the time step size. Based on the numerical results, it is evident that the method exhibits remarkable accuracy and efficiency when applied to plane elasticity problems including forced, harmonic, and free analyses. As compared to conventional numerical methods for dynamic analysis, the method outperforms in both accuracy and convergence rate. [ABSTRACT FROM AUTHOR]

A novel higher-order multi-scale computational approach for efficient nonlocal gradient elasticity simulation of composite materials is proposed in this paper. Based on the use of decoupling technique, raw fourth-order nonlocal gradient equations with periodically oscillatory coefficients are decoupled as the new second-order multi-scale equations for reducing the continuity requirements when implementing multi-scale simulation. Next, a novel macro-micro coupled multi-scale computational model with higher-order corrected terms is rigorously devised for high-resolution multi-scale and nonlocal analysis of composite materials via multi-scale asymptotic analysis. Then, the local error analysis of higher-order multi-scale solutions in the point-wise sense illustrates that establishing higher-order asymptotic corrected terms plays a vital role in investigating the micromechanical mechanisms. Moreover, a rigorous global error estimation with an explicit rate of higher-order multi-scale solutions is first derived in the energy norm sense. In addition, an efficient multi-scale numerical algorithm is presented to effectively simulate nonlocal gradient elasticity problems of composite materials based on finite element method (FEM). And we also derive the convergence estimation of the proposed numerical algorithm. Finally, numerical experiments are conducted to gauge the efficiency and accuracy of the proposed higher-order multi-scale method. This paper offers a unified higher-order two-scale computational framework for enabling nonlocal gradient elasticity behavior simulation of composite materials. [ABSTRACT FROM AUTHOR]

In recent times, there has been a burgeoning interest in harnessing natural plant extracts for the development of innovative biological scaffolds. This article centers on the extraction of Parrotia persica extract and explores its potential suitability for integration into nanofibrous structures. In pursuit of this objective, nanofibers were meticulously crafted using a blend of polyvinyl alcohol (PVA) and the derived Parrotia persica extract (E), employing the electrospinning technique. Different PVA/E ratios (90:10, 80:20, and 50:50) were investigated. The formation of layer-by-layer structures (four layers) was achieved by sequentially electrospinning a layer of PCL nanofibers onto a collector, followed by the deposition of a layer of PVA/E ((80:20) and (50:50)) with the identical thickness. The results revealed that the layered fibers exhibited a strikingly three-dimensional architecture, closely resembling the natural extracellular matrix. Notably, among the samples, the PCL-PVA/E (80:20)-PCL composition demonstrated the most favorable morphology, featuring a contact angle of approximately 40.45° and a diameter measuring 403 nm. Fourier transform infrared spectroscopy (FTIR) analysis conclusively confirmed the presence of Parrotia persica extract, PVA, and PCL within the intricate layers. Furthermore, fibroblast cell culture observations revealed the attachment and spreading of cells on the surface of the PVA/E (80:20)-PCL samples, underscoring their potential for facilitating cellular growth and tissue regeneration.Taking into account their highly desirable hydrophilic properties, the incorporation of Parrotia persica extract with its antibacterial and antioxidant attributes, as well as the presence of PCL endowed with elastic properties akin to those of natural skin, the prepared nanofibrous structures exhibit a promising outlook as viable skin substitutes. [ABSTRACT FROM AUTHOR]

In this article, a thermomagnetic viscoelastic nonlocal model has been introduced that incorporating the nonlocal elasticity theory of Eringen and the Kelvin–Voigt type. In the heat conductivity equation, the dual-phase-lag thermoelastic model (DPL) has been used to account for microstructural effects caused by high-rate heat transfer processes. The proposed DPL thermoelastic model illustrates the effects of material deficiencies and the thermomechanical relationship due to the extremely rapid heating. Within the framework of the nonlocal DPL model, a one-dimensional magneto-thermoelastic problem of half-space whose surface is exposed to an instantaneous heat source and magnetic field has been studied. With the eigenvalue approach technique and Laplace transform method, analytical solutions for the studied physical fields are provided. The transformed expressions to the field quantities are reversed into the physical domain by applying Zakian's algorithm. The effects of the nonlocal parameter, the viscosity and the applied heat source have been shown graphically on the differences in the fields within the medium. [ABSTRACT FROM AUTHOR]