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It is important and difficult to improve the tensile strength of backfill material to ensure the stability of goafs. In this study, rice straw (RS) in fiber form is used to improve the tensile properties of cemented paste backfill (CPB). An orthogonal experiment was designed, Brazilian indirect tensile strength tests were conducted to test the tensile performance of RS fiber-reinforced cemented paste backfill (RSCPB) under different fiber content (1, 2, 3 kg/m3) and fiber length (0.8~1, 1~3, 3~5 cm), and the microstructure of RSCPB was analyzed with scanning electron microscopy (SEM). The results showed that, compared with the conventional cemented paste backfill (CCPB), the increase in tensile strength of RSCPB ranged from 115.38% to 300.00% at 3 days curing age, 40.91% to 346.15% at 7 days, and −38.10% to 28.00% at 28 days, and the strain was slightly reduced during the curing period. The tensile strength, strain, and percentage increase of the RSCPB compared to the CCBP did not show a monotonic pattern of variation with the RS fiber content and length during the curing period. The RSCPB samples fractured under peak stress, showing obvious brittle failure. In addition, sulfate generated from S2− in the tailings inhibits the hydration reaction, and generates swelling products that form weak structural surfaces, which, in turn, lead to a 28-day tensile strength and strain of RSCPB lower than those at 7 days.

This study aimed to investigate the effects of different magnitudes and durations of static tensile strain on human periodontal ligament cells (hPDLCs), focusing on osteogenesis, mechanosensing and inflammation. Static tensile strain magnitudes of 0%, 3%, 6%, 10%, 15% and 20% were applied to hPDLCs for 1, 2 and 3 days. Cell viability was confirmed via live/dead cell staining. Reference genes were tested by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and assessed. The expressions of TNFRSF11B, ALPL, RUNX2, BGLAP, SP7, FOS, IL6, PTGS2, TNF, IL1B, IL8, IL10 and PGE2 were analyzed by RT-qPCR and/or enzyme-linked immunosorbent assay (ELISA). ALPL and RUNX2 both peaked after 1 day, reaching their maximum at 3%, whereas BGLAP peaked after 3 days with its maximum at 10%. SP7 peaked after 1 day at 6%, 10% and 15%. FOS peaked after 3 days with its maximum at 3%, 6% and 15%. The expressions of IL6 and PTGS2 both peaked after 1 day, with their minimum at 10%. PGE2 peaked after 1 day (maximum at 20%). The ELISA of IL6 peaked after 3 days, with the minimum at 10%. In summary, the lower magnitudes promoted osteogenesis and caused less inflammation, while the higher magnitudes inhibited osteogenesis and enhanced inflammation. Among all magnitudes, 10% generally caused a lower level of inflammation with a higher level of osteogenesis.

Electrocatalytic reduction of dinitrogen to ammonia has attracted significant research interest. Herein, it reports the boosting performance of electrocatalytic nitrogen reduction on Ti 2 CO 2 MXene with an oxygen vacancy through biaxial tensile strain engineering. Specifically, tensile strain modified electronic structures and formation energy of oxygen vacancy are evaluated. The exposed Ti atoms with additional electron states near the Fermi level serve as active site for intermediate adsorption, leading to superior catalytic performance (U limit = -0.44 V) under 2.5% biaxial tensile strain through a distal mechanism. However, the two sides of the "Sabatier optimum" in volcano plot are not limited by two different electronic steps, but are induced by the diverse adsorption behaviors of intermediates. Crucially, the "Sabatier optimum" results from the different response speeds of the adsorption energy for *N 2 and *NNH to strains. Moreover, the authors observe conventional d-band adsorption for *N 2 and *NNH, non-linear adsorption for *NNH 2 , and abnormal d-band adsorption for *N, *NH, *NH 2 , and *NH 3 , which can be explained by the competition between attractive orbital hybridization and repulsive orbital orthogonalization with the spin-polarized d-band model, which further clarifies the contributions of 3σ → d z2 and d xz /d yz → 2π* to the overall population of bonding and anti-bonding states., (© 2023 Wiley-VCH GmbH.)

It is critical that human adipose-derived stromal/stem cell (hASC) tissue engineering therapies possess appropriate mechanical properties in order to restore the function of the load-bearing tissues of the musculoskeletal system. In an effort to elucidate hASC response to mechanical stimulation and develop mechanically robust tissue-engineered constructs, recent research has utilized a variety of mechanical loading paradigms, including cyclic tensile strain, cyclic hydrostatic pressure, and mechanical unloading in simulated microgravity. This chapter will describe the methods for applying these mechanical stimuli to hASC to direct differentiation for functional tissue engineering of the musculoskeletal system., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Crack phenomenon is one of the most well-known mechanisms to turn a conductive thin film into a strain sensor. However, there is a limitation that most of the crack-based strain sensors using elastomeric materials with high Poisson’s ratio only allow uni-axial deformation because unintended cracks are easily formed into arbitrary directions even under low strain. Therefore, if directional crack formation can be engineered and thus a strain sensor only responds to a specific axial-direction strain, it can be used as an excellent trigger sensing deformation direction and will act an interesting role in various stretchable electronics fields. In this work, we introduce an anisotropic crack formation mechanism and implement micro-crack based strain sensors with silver thin films that are inkjet-printed on an asymmetrically pre-strained roughened poly(dimethylsiloxane) (PDMS) substrate. Anisotropic crack formation combined with the asymmetric buckling structure remarkably differentiates sensors’ sensitivity to axial directions of the applied strain. We demonstrate a resolution-sustainable and 2-dimensionally stretchable LED array with feedback functionality between sensing strain directions and turning on corresponding axial LEDs by using two orthogonally arranged strain sensors. This work will provide an insight emphasizing a new role of strain sensors in stretchable electronics applications. [ABSTRACT FROM AUTHOR]

The detection of mechanical stretching is usually based on piezoresistive effect made up of piezoelectric material. Here, we report a novel approach of autonomous contactless stretch sensor for detection of varying electric field based on electret technology. The present work proposes a novel approach that detects low-noise with high sensitivity for various stretch-based applications. Nanoparticle filled thin-film polymeric membrane are activated by corona injection to trap the charges and form a permanently charged electret and the contactless fixed electrode pair continuously monitors the change in electric field exerted by the tensile strain/deformation on the polymeric membrane. The sensor detects a peak output response of 4.7 V under 20% cyclic tensile strain with a sensitivity of 56 mV/%strain. By considering these merits of simple and scalable fabrication, outstanding performance and robust characteristic, we believe the autonomous contactless stretch sensor can open great opportunities not only for low-noise sensing/detection applications but can contribute to multitude large-scale applications such as intrusion detectors, microphones, pressure monitoring, sensing for security and safety applications. [ABSTRACT FROM AUTHOR]

To investigate the behavior of laterally loaded piles within mechanically stabilized earth (MSE) walls, reduced-scale physical model tests of single piles within the MSE walls were conducted inside a test box. Sensors were installed in each model test to monitor the responses of the wall facing and the pile during the laterally loaded pile test. The test results show that the lateral capacity of the pile at the distance of two times pile diameter behind the wall facing decreased by 21% as compared with that at four times pile diameter. The model test results were compared well with those of the full-scale field tests. An empirical relationship was developed to estimate the pile-induced maximum wall facing displacements. This paper describes an additional lateral earth pressure distribution on the wall facing based on test results, which may be used to estimate the pile-induced maximum tensile forces in the geosynthetic layers at different elevations. [ABSTRACT FROM AUTHOR]

A novel low ON-resistance strained lateral double-diffused MOSFET (LDMOS) with silicon-carbon (Si1−yCy) source is proposed for low-voltage applications. Due to the lattice mismatch between silicon and Si1−yCy, the source-side Si1−yCy stressor introduces the lateral tensile stress and vertical compressive stress along the conduction path to enhance the electron mobility in the channel and drift regions and hence improves the ON-state characteristics. As the stress relaxation in the drift region, the strain-induced breakdown voltage (BV) deterioration can be neglected. The simulation results show that the ON-resistance (Ron) of the proposed device is decreased by 19.2% compared with the conventional LDMOS without strain at a gate overdrive voltage (VGS – VT) of 1 V. At the same time, the novel LDMOS achieves 47% and 28.8% increment in the drive current (ID,sat) and peak transconductance (Gm,peak), respectively, while keeping a nearly identical BV of 23.08 V. Besides, the improved cutoff frequency (ƒT) and transconductance-to-current ratio (Gm/ID) are also obtained in the novel LDMOS. [ABSTRACT FROM AUTHOR]

Continuous fiber reinforced polyamide composite parts were manufactured by 3T) printing additive manufacturing (ALM). Scanning electron microscope (SEM) was used to observe the microphotographs of 3T) printing single filaments made of composite materials? and tensile and compression performance tests were used to evaluate the mechanical properties of composite materials. The results showed that the surface treatment of the fiber results in chemical reaction between the silane coupling agent and the glass fiber surface. The surface of 3T) printing glass fiber was attached with a large number of polyamide materials? and the combination was good. The tensile curves along the fiber direction of the sample changed linearly with strain until it broke. When the stress reached 55() MPa? the sample broke and the tensile strain was 4.23%. Tn the direction perpendicular to the fiber, the breaking strength could reach 1 ().56 MPa? and the tensile strain was 1.32% when the sample broke. The compressive fracture strength of the composite along the fiber direction could reach 86.82 MPa? and the compressive strain was 0.62% when the sample broke. Tn the direction perpendicular to the fiber ? the compressive fracture strength could reach 13.95 MPa? and the compressive strain was 1.22% when the sample broke. [ABSTRACT FROM AUTHOR]

Tensile tests of aluminum plate repaired with carbon fiber sheet were conducted, the effects of bonding length, layer number and bonding way on load transfer had been discussed, the failure process, failure characteristics, strain distribution and change law were also analyzed, Effects of CFRP reinforced intact specimens and damaged specimens were compared. Test results indicate that adopt double adhesive, the load of damaged specimen can be greatly increased while has no significant effect on intact sample. Increasing layer number can improve the bearing capacity of repaired specimen and reduce the strain gradient at the end and damaged region, also the stress concentration problem is eased. Although the improvement of bearing capacity is limited through increasing the length of carbon fiber sheet, the stress distribution of glue layer has been improved, the strain gradient at the end and damaged region are also reduced, so it is conducive to improve the whole performance of repaired component.

Abstract Recent theoretical studies indicated that the Curie temperature of perovskite manganite thin films can be increased by more than an order of magnitude by applying appropriate interfacial strain to control orbital ordering. In this work, we demonstrate that the regular intercalation of BaTiO3 layers between La0.67Sr0.33MnO3 layers effectively enhances ferromagnetic order and increases the Curie temperature of La0.67Sr0.33MnO3/BaTiO3 superlattices. The preferential orbital occupancy of eg(x 2 –y 2 ) in La0.67Sr0.33MnO3 layers induced by the tensile strain of BaTiO3 layers is identified by X-ray linear dichroism measurements. Our results reveal that controlling orbital ordering can effectively improve the Curie temperature of La0.67Sr0.33MnO3 films and that in-plane orbital occupancy is beneficial to the double exchange ferromagnetic coupling of thin-film samples. These findings create new opportunities for the design and control of magnetism in artificial structures and pave the way to a variety of novel magnetoelectronic applications that operate far above room temperature.

By adopting the first-principles plane wave pseudopotential method based on density functional theory, the electronic structure properties of single-layer MoS2 (molybdenum disulfide) crystals under biaxial strain are studied. The calculation results in this paper show that when a small strain is applied to a single-layer MoS2, its band structure changes from a direct band gap to an indirect band gap. As the strain increases, the energy band still maintains the characteristics of the indirect band gap, and the band gap shows a linear downward trend. Through further analysis of the density of states, sub-orbital density of states, thermodynamic parameters and Raman spectroscopy, it revealed the variation of single-layer MoS2 with strain. This provides a theoretical basis for realizing the strain regulation of MoS2.

For a superconducting Bi2Sr2CaCu2Ox (Bi2212) multifilamentary composite round wire (RW), typically the interface between Bi2212 filaments and the Ag matrix become extremely complex after heat treatment, and all the time the question of how the unique interface structure affect the macro properties such as mechanical, electrical, and thermal behaviors has not been satisfactorily answered, mainly because it is very hard to in situ measure the microstructure evolution and further evaluate its effect on these macro properties. Therefore, for this purpose, in this article, we made the modeling and numerical study on the role of the Bi2212/Ag interface in the mechanical and electrical behaviors of composite RWs. By using the randomly generated polygons method, we first reconstructed the cross section of Bi2212 composite RWs, especially in this reconstruction the complex Bi2212/Ag interface can be effectively characterized. On both of two models with and without the complex interface, we obtained the thermally residual stresses and strains due to cooling down from heat treatment, and then the mechanical response from the applied tensile strain. The comparative study further revealed that, for a practical Bi2212 RW with the complex interface, the distributions of the stress and strain are more uniform, which make the wire tend to safely and equivalently increase its limiting load capacity according to the maximum principal stress theory. In order to deeply understand the degradation of the critical current Ic under applied tensile strain ε of Bi2212 RWs, we presented a current sharing model in which the current shares both in Bi2212 filaments and surrounding Ag matrix, taking into account the obstacle of cracks in the filament. By comparing the calculated Ic - ε curve with experimental data, the Ic degradation with the ε was very well interpreted by the mechanical damage and fracture of the microstructure of Bi2212 RWs. [ABSTRACT FROM AUTHOR]

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N-type heavy doping and tensile strain can significantly improve the luminescence efficiency of Ge materials. The active region of the quantum dot(QD) structure can realize high luminous efficiency due to its 3D carrier confinement. In this study, we constructed a Si-based QD array laser by introducing a 0.25% biaxial tensile strain and 4 × 10 19 cm − 3 N type heavy doping to Ge. A band-lifting method was proposed to determine the optimum doping concentration and thus improve the luminescence efficiency of Ge. To obtain accurate characteristics of the laser, we constructed a calculation model of three band transitions and all of the k-space quantum transitions of Ge and other relevant modified models. Results showed that the laser power was 5.31 μ W at a voltage of 2.5 V, and the laser wavelength reached 1519.4 nm at room temperature. The proposed laser can be used as a light source compatible with the Si-based CMOS process. [ABSTRACT FROM AUTHOR]

We extend the previous 30-band k ⋅ p model effectively employed for relaxed Ge1-xSnx alloy to the case of strained Ge1-xSnx alloy. The strain-relevant parameters for the 30-band k ⋅ p model are obtained by using linear interpolation between the values of single crystal of Ge and Sn that are from literatures and optimizations. We specially investigate the dependence of band-gap at L-valley and Γ-valley with different Sn composition under uniaxial and biaxial strain along [100], [110] and [111] directions. The good agreement between our theoretical predictions and experimental data validates the effectiveness of our model. Our 30-band k ⋅ p model and relevant input parameters successfully applied to relaxed and strained Ge1-xSnx alloy offers a powerful tool for the optimization of sophisticated devices made from such alloy. [ABSTRACT FROM AUTHOR]

The paper presents an extensometer designed to measure two mechanical strains at the same time—one from tensile load and the other from torsion load. Strain transducers provide different electric signals, which, after calibration, lead to the simultaneous measurement of linear (ε) and angular (γ) strains. Each of these two signals depends on the measured process and is not influenced by the other strain process. This extensometer is designed to be easily mounted on the sample with only two mounting points and can be used to measure the combined cyclical fatigue of tensile and torsional loadings. This extensometer has two bars—one rigid, reported at the resulting stress points, and one elastic and deformable. The elastic deformable bar has two beams with different orientations. When the sample is deformed, both beams are loaded by two bending moments (perpendicular to each other and both perpendicular on the longitudinal axis of the bars). [ABSTRACT FROM AUTHOR]

Background and objective: Bone remodeling during orthodontic treatment is achieved by the osteogenesis of human periodontal ligament cells (PDLCs) subjected to mechanical loadings. Transcriptional co‐activator with PDZ‐binding motif (TAZ) mediates bone remodeling in response to extracellular mechanical signals. This study aims to investigate the role of TAZ in osteogenesis of PDLCs under tensile strain. Materials and methods: A uniaxial cyclic tensile stress (CTS) at 12% elongation and 6 cycles/min (5 s on and 5 s off) was applied to PDLCs. The osteogenic differentiation was determined by the protein and gene expressions of osteogenic markers using qRT‐PCR and Western blot, respectively, and further by alkaline phosphatase (ALP) activity and Alizarin Red S staining. The interaction of TAZ with core‐binding factor α1 (Cbfα1) was examined by co‐immunoprecipitation. The immunofluorescence histochemistry was used to examine the nucleus aggregation of TAZ and the reorganization of actin filaments. Moreover, small interfering RNA‐targeting TAZ (TAZsiRNA) was used for TAZ inhibition and Y‐27632 was employed for Ras homologue‐associated coiled‐coil protein kinase (ROCK) signaling blockage. Results: CTS clearly stimulated the nucleus accumulation of TAZ and its interaction with Cbfα1. CTS‐induced osteogenesis in PDLCs was significantly abrogated by the infection with TAZsiRNA, as shown by the decreased stained nodules and protein expressions of Cbfα1, collagen type I, osterix, and osteocalcin, along with the inhibition of β‐catenin signaling. Moreover, ROCK inhibition by Y‐27632 hindered TAZ nucleus aggregation and its binding with Cbfα1, which subsequently lead to the decreased osteoblastic differentiation of PDLCs. Conclusions: Taken together, we propose that TAZ nucleus localization and its interaction with Cbfα1 are essential for the CTS‐induced osteogenic differentiation in PDLCs. And such TAZ activation by CTS could be mediated by ROCK signaling, indicating the pivot role of ROCK‐TAZ pathway for PDLCs differentiation. [ABSTRACT FROM AUTHOR]

In this work we have studied the effects of the tensile mechanical strain on the electrical behavior of a roll-to-roll printed solar cell module with silver electrodes. After applying the strain along the length of the solar module, its current-voltage curves were measured in dark and under light illumination conditions. By electrical parameters extraction of the curves in both conditions, valuable information was achieved which proved that the dark and light parameters are in good agreement with each other and can each be used as a means to evaluate the solar cells. Electrical parameters like series resistance and power conversion efficiency, all show improvements for moderate tensile strain levels. The power conversion efficiency had about 3.8% improvement after applying 2400 $\mu {\varepsilon }$ tensile strain. This is due to the polymer chains alignment in the direction of the applied tensile strain. However, higher strain levels damaged the interfaces among the solar cells’ layers. These broken bonds created a high density of defect states and thus reduced the electrical performance of the solar cell. This research showed that the solar cell under the test can be mechanically deformed under moderate strains while showing a better electrical performance. So these cells are a suitable choice for applications in which the cells are used under a mechanical tensile strain. [ABSTRACT FROM AUTHOR]

It poses a great challenge to design anode materials with large capacity, excellent cyclic stability and high rate performance. In this paper, through first principle calculations, we computed electronic properties of monolayer WSe 2 with and without strain effects. Our results show that the electronic band gap decreases with strain percent. At 0% tensile strain the value of the band gap is 1.4 eV while at 10% tensile strain the band gap decreases to 0.7 eV. Therefore, the strain effect enhances the electronic conductivity and leads to an increase in the charge carrier transport. In addition, our predictions show that the adsorption energy increases with the strain. Finally, we computed the diffusion barrier for the migration of Li on the surface of a strain engineered WSe 2 monolayer. The lower barrier energy (0.24 eV) reveals that Li can easily overcome this barrier. Our results show that the strain-engineered WSe 2 monolayers are promising anode material for Li-ion battery. • Monolayer WSe 2 study with and without strain effects. • Li–adsorption on the strain engineered WSe 2 monolayer. • Electronic band gap decreases with strain percent. • Conductivity enhances which leads to an increase in the charge carrier transport. • Strain-engineered 1L-WSe 2 is a promising anode material for Li-ion battery. [ABSTRACT FROM AUTHOR]

A new method to induce tensile stress in a PDSOI NMOS device for RF applications is proposed, which is based on relaxing a SiGe layer built underneath silicon. By means of TCAD simulations, we demonstrate that stress transfer from SiGe to Si occurs by means of at least two different mechanisms: SiGe relaxation due to amorphization and the formation of Stacking Faults during recrystallization. By considering both phenomena, a tensile stress of 0.5 GPa can be injected into the silicon channel. Moreover, the impact of annealing steps on the detrimental out-of-SiGe Ge diffusion has been simulated by considering an inter-diffusion model, showing the importance of adapting the PDSOI process flow to account for the presence of the new stressor. [ABSTRACT FROM AUTHOR]

• The aerodynamic intensification effect in the lining crack is revealed. • The intensification effect of the circumferential crack is the most significant. • RSMs are established to predicate the maximum tensile strain of the crack tip. • The tensile strain is 0.37 times of the maximum tensile strain of concrete. Falling concrete blocks are serious problems in high-speed railway tunnels, and they cause delays of high-speed trains (HSTs) and even compromise driving safety. When HST-induced aerodynamic shockwaves propagate into cracks, the intensified pressure makes the cracks grow and connect, resulting in falling concrete blocks. In this study, the longitudinal, oblique and circumferential cracks at the tunnel vault are selected as representatives. The temporal, spatial and spectral characteristics of the aerodynamic pressure in the cracks are studied using the unsteady viscous k-ε turbulence model. The aerodynamic intensification effect in the lining crack is also revealed. Results show that the maximum pressure of the circumferential crack is 1.51 and 1.37 times that of the longitudinal and oblique cracks, respectively. On the basis of the results of soil–tunnel–crack models established in ABAQUS, two response surface models (RSMs) are established to quantify the effects of important factors, including crack length, crack depth, crack width, incident angle of the aerodynamic shockwave and train velocity, on the maximum tensile strain of the crack tip of circumferential cracks. Train velocity exerts the greatest influence on the maximum tensile strain in the circumferential crack, followed by crack width. Moreover, a field measurement is performed to investigate the dynamic strain of crack tips under train-induced aerodynamic loads and verify the proposed RSM. The maximum tensile strain caused by aerodynamic pressure is approximately 0.31–0.86 times of the maximum tensile strain of concrete. The proposed RSM can realise a reasonable prediction of the dynamic strain of crack tips. This research may be valuable for analysing the crack tip stability of tunnel lining cracks and guaranteeing the structural health of high-speed railway tunnels. [ABSTRACT FROM AUTHOR]

• Physical tests are conducted to explore pipe response to tunnel active face failure. • Pipe deformations reach maximum values at normalized horizontal distance of 0.1 D. • Effect of C/D ratio on pipe deformations is less prominent than that of H/D ratio. • Measured results verify calculation chart for estimating pipe tensile strain. In congested urban areas, earth pressure balance (EPB) shielding is commonly adopted to alleviate tunneling effects on surrounding structures. Tunnel active face instability can cause excessive ground movements, which threaten the serviceability of nearby underground pipelines. However, previous studies mainly focused on tunnel face support pressure and tunnel face failure induced ground movements, while pipeline deformations due to tunnel active face instability are seldomly explored. In this study, a series of physical model tests are designed and conducted to investigate the effects of tunnel cover to diameter ratio (C/D) and normalized horizontal distance (H/D) between tunnel face and existing pipeline on three-dimensional pipeline deformation mechanisms. Tunnel active face instability induces excessive settlements and tensile strains in the existing pipeline when it is located at 0.1 D ∼ 0.3 D in front of tunnel face. By increasing H/D ratio from 0.1 to 0.5, the maximum settlement and tensile strain of the existing pipeline decrease by up to 64.8% and 59.9%, respectively. But the maximum settlement and tensile strain of the pipeline only decrease by up to 14.9% and 7.3%, respectively, as C/D ratio increases from 1.0 to 1.5. Obviously, the effects of C/D ratio on pipeline response are less prominent than that of H/D ratio. The measured results are used to verify calculation charts for directly predicting maximum tensile strains of existing pipelines due to tunnel face active instability induced differential ground movements. [ABSTRACT FROM AUTHOR]

Despite the significant progress in high thermal-resisting photocurable resin, the simultaneous achievement of robustness, stretchability, and dielectric properties in modified naphthalene-type photocurable resin remains a great challenge owing to intrinsic restrictions mediated by strong π-π stacking effect. Herein, a simple and feasible method is demonstrated to respectively introduce three selected di-functional acid chain extenders into 1,6-naphthalene diglycidyl ether (NDE), and prepare a series of naphthalene-type photocurable enhancement resin with excellent thermal/mechanical properties and low dielectric traits. Most importantly, the effect of the increase of succinic acid (SA) chain-extending segments on the thermal and mechanical properties of SA chain-extending NDE (S-NDE) resin is systematically investigated. An optimized synthesized route is presented by chain extension chemical strategy, which enables the improvement of the "seesaw" issue between high heat resistance and mechanical robustness. As a consequence, the optimized UV-curing S-NDE thin film exhibits robust tensile strength (75.45 ± 4.46 MPa), excellent heat resistance (T g : 145.4 °C), high stretchability (7.22 ± 0.85 %), and desired dielectric constant (2.2). Meanwhile, the uncured S-NDE resin exhibited an excellent alkali elution property within 5 min. An actually printed circuit board (PCB) solder resistance coating/patterning application is further demonstrated based on the selective elution property of high-performance formulated S-NDE green ink, providing an efficient strategy for the design and fabrication of high-performance naphthalene-type photocurable materials. [Display omitted] • Photosensitive naphthalene-type resin was successfully synthesized by an esterification reaction. • Alkyl bridging units dwindling π-conjugated stacking effect contributes to toughening and strengthening dielectric properties. • Optimized UV-curing S-NDE thin film with outstanding properties was developed. • Unprecedented tensile strain and high T g were favorably balanced. [ABSTRACT FROM AUTHOR]

Abstract We theoretically investigate highly tensile-strained Ge nanowires laterally on GaSb. Finite element method has been used to simulate the residual elastic strain in the Ge nanowire. The total energy increment including strain energy, surface energy, and edge energy before and after Ge deposition is calculated in different situations. The result indicates that the Ge nanowire on GaSb is apt to grow along 〈100〉 rather than 〈110〉 in the two situations and prefers to be exposed by {105} facets when deposited a small amount of Ge but to be exposed by {110} when the amount of Ge exceeds a critical value. Furthermore, the conduction band minima in Γ-valley at any position in both situations exhibits lower values than those in L-valley, leading to direct bandgap transition in Ge nanowire. For the valence band, the light hole band maxima at Γ-point is higher than the heavy hole band maxima at any position and even higher than the conduction band minima for the hydrostatic strain more than ∼5.0%, leading to a negative bandgap. In addition, both electron and hole mobility can be enhanced by owing to the decrease of the effective mass under highly tensile strain. The results suggest that biaxially tensile-strained Ge nanowires hold promising properties in device applications.

A variety of factors such as amount of load, velocity, wheel impact, time (loading rate), rest periods, temperature, and stress state, loading modes, aging and moisture can affect the asphalt behavior against deformation and efficiency. One of the most important factors is the effect of velocity on the tensile strain of the asphalt sub-layer, which leads to the most common type of failure (fatigue). In this study, using Abaqus, Ansys and 3D move soft wares, the desired and then a comparison between these three soft wares has been made. Dynamic modeling is conducted relying on the elastic behavior of layers. The study also includes the impact of loading speed on tensile strain of asphalt sub-layer. Results have indicated that Abaqus software compared with Ansys operates faster and more comprehensive for pavement analysis. In addition, 3D move compared with Abaqus and Ansys operates more rapidly in various model of the visco, but Abaqus has a more varied and stronger dynamic analysis. The comparisons between different velocities showed that high velocities include less fatigue failure. In general, the impact of velocity on the tensile strain in the asphalt sub-layer is more remarkable at low velocities. At low velocities, changes occur due to approaching to the static mode.

Two-dimensional (2D) ferroelectrics are promising candidates in the field of microelectronics due to their unique properties such as excellent photoelectric responsiveness. However, the thermal properties of 2D ferroelectrics are less investigated. Here, the thickness dependent thermal conductivity in ferroelectric α -In 2 Se 3 is systematically investigated by the first-principles method combined with the phonon Boltzmann transport equation. On this basis, the strain and oxidation effects on the thermal conductivity of monolayer α -In 2 Se 3 is further studied. The calculation results show that the thermal conductivity has a significant reduction with decreasing film thickness or increasing tensile strain, and the anharmonic phonon-phonon scattering rate is the intrinsic mechanism for the reduction in thermal conductivity. On the other hand, the replacement of Se atoms by O atoms can achieve a bidirectional and wide-range (12×) tuning of thermal conductivity. The increase in specific heat and phonon group velocity is responsible for the thermal conductivity enhancement at high doping levels while that in phonon-phonon scattering rate is responsible for the thermal conductivity reduction at low doping levels. In all cases, acoustic phonons dominate the in-plane thermal transport behavior. These findings broaden our understanding of phonon transport and its control in ferroelectric semiconductor α -In 2 Se 3 ., (© 2023 IOP Publishing Ltd.)

Molybdenum ditelluride (MoTe 2 ) exhibits immense potential in post-silicon electronics due to its bandgap comparable to silicon. Unlike other 2D materials, MoTe 2 allows easy phase modulation and efficient carrier type control in electrical transport. However, its unstable nature and low-carrier mobility limit practical implementation in devices. Here, a deterministic method is proposed to improve the performance of MoTe 2 devices by inducing local tensile strain through substrate engineering and encapsulation processes. The approach involves creating hole arrays in the substrate and using atomic layer deposition grown Al 2 O 3 as an additional back-gate dielectric layer on SiO 2 . The MoTe 2 channel is passivated with a thick layer of Al 2 O 3 post-fabrication. This structure significantly improves hole and electron mobilities in MoTe 2 field-effect transistors (FETs), approaching theoretical limits. Hole mobility up to 130 cm -2  V -1 s -1 and electron mobility up to 160 cm -2  V -1 s -1 are achieved. Introducing local tensile strain through the hole array enhances electron mobility by up to 6 times compared to the unstrained devices. Remarkably, the devices exhibit metal-insulator transition in MoTe 2 FETs, with a well-defined critical point. This study presents a novel technique to enhance carrier mobility in MoTe 2 FETs, offering promising prospects for improving 2D material performance in electronic applications., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Electrochemical oxygen evolution reaction (OER) kinetics are heavily correlated with hybridization of the transition metal d-orbital and oxygen intermediate p-orbital, which dictates the barriers of intermediate adsorption/desorption on the active sites of catalysts. Herein, a strategy is developed involving strain engineering and coordination regulation to enhance the hybridization of Ni 3d and O 2p orbitals, and the as-synthesized Ni-2,6-naphthalenedicarboxylic acid metal-organic framework (DD-Ni-NDA) nanosheets deliver a low OER overpotential of 260 mV to reach 10 mA cm -2 . By integrating an alkaline anion exchange membrane electrolyzer and Pt/C electrode, 200 and 500 mA cm -2 current densities are reached with cell voltages of 1.6 and 2.1 V, respectively. When loaded on a BiVO 4 photoanode, the nanosheet enables highly active solar-driven water oxygen. Structural characterizations together with theoretical calculations reveal that the spin state of the centre Ni atoms is regulated by the tensile strain and unsaturated coordination defects in DD-Ni-NDA, and such spin regulation facilitates spin-dependent charge transfer of the OER. Molecular orbital hybridization analysis reveals the mechanism of OH* and OOH* adsorption energy regulation by changes in the DD-Ni-NDA spin state, which provides a deeper understanding of the electronic structure design of catalysts for the OER., (© 2023 Wiley-VCH GmbH.)

Introduction: The goal of this study was to investigate how concurrent shear stress and tensile strain affect endothelial cell biomechanical responses. Methods: Human coronary artery endothelial cells were exposed to concurrent pulsatile shear stress and cyclic tensile strain in a programmable shearing and stretching device. Three shear stress–tensile strain conditions were used: (1) pulsatile shear stress at 1 Pa and cyclic tensile strain at 7%, simulating normal stress/strain conditions in a healthy coronary artery; (2) shear stress at 3.7 Pa and tensile strain at 3%, simulating pathological stress/strain conditions near a stenosis; (3) shear stress at 0.7 Pa and tensile strain at 5%, simulating pathological stress/strain conditions in a recirculation zone. Cell morphology was quantified using immunofluorescence microscopy. Cell surface PECAM-1 phosphorylation, ICAM-1 expression, ERK1/2 and NF-κB activation were measured using ELISA or Western blot. Results: Simultaneous stimulation from pulsatile shear stress and cyclic tensile strain induced a significant increase in cell area, compared to that induced by shear stress or tensile strain alone. The combined stimulation caused significant increases in PECAM-1 phosphorylation. The combined stimulation also significantly enhanced EC surface ICAM-1 expression (compared to that under shear stress alone) and transcriptional factor NF-κB activation (compared to that under control conditions). Conclusion: Pulsatile shear stress and cyclic tensile strain could induce increased but not synergistic effect on endothelial cell morphology or activation. The combined mechanical stimulation can be relayed from cell membrane to nucleus. Therefore, to better understand how mechanical conditions affect endothelial cell mechanotransduction and cardiovascular disease development, both shear stress and tensile strain need to be considered. [ABSTRACT FROM AUTHOR]

Engineered skeletal muscle grafts may be employed in various applications including the treatment of volumetric muscle loss (VML) and pharmacological drug screening. To recapitulate the well-defined structure of native muscle, tensile strains have been applied to the grafts. In this study, we cultured C2C12 murine myoblasts on electrospun fibrin microfiber bundles for 7 days in custom-built bioreactor units and investigated the impact of strain regimen and delayed onset of tensile straining on myogenic outcomes. The substrate topography induced uniaxial alignment of cells in all (strained and unstrained) groups. The engineered grafts in strained groups were subjected to 10% strain amplitude for 6 h per day. We found that both static and cyclic uniaxial strains resulted in similar morphological and gene expression outcomes. However, relative to 0% strain groups, there were stark increases in myotube diameter, myosin heavy chain (MHC) coverage, and expression of key myogenic genes (Pax 7, Troponin, MHC I, MHC IIb, MHC IIx) only if strain was applied at Days 5–7 rather than Days 3–7. This finding suggests that a critical indicator of myogenic improvement under strain in our system is the phenotype of the cells at the onset of strain and suggests that this is a key parameter that should be considered in studies where myoblasts are subjected to biophysical stimulation to promote tissue formation. This is the first report on the impact of the timing of the initial application of mechanical strain for improving the myogenic outcomes of 3D engineered skeletal muscle grafts. In this work, immature skeletal myoblasts were grown on topographically aligned, electrospun fibrin microfiber bundles and we applied 10% uniaxial static or cyclic strain. We concluded that the maturity of myoblasts prior to strain application, rather than strain waveform, was the primary predictor of improved myogenic outcomes, including myogenic gene expression and myotube morphology. Elucidating the optimal conditions for strain application is a vital step in recapitulating physiological myogenic properties in tissue engineered skeletal muscle constructs, with applications for treating volumetric muscle loss, disease modeling, and drug testing. [ABSTRACT FROM AUTHOR]

Ge emerges as a good candidate for the active layer in optoelectronic devices and is compatible with complementary metal oxide semiconductor technology. As the Ge band structure exhibits an indirect band gap with a small difference in energy between the direct and the indirect valleys (about 140 meV), the energy band structure can be modified by applying a tensile strain or by doping electrons into the film to turn Ge into a semiconductor material with a direct ban gap structure. In this work, Ge epilayers were grown on Si substrate by molecular beam epitaxy technique, and we show that the tensile strain value of the Ge epilayers increases by a factor of two by doping electrons into the films with two donor elements using GaP and Sb sources. The dopant concentration in Ge epilayers is 5.6 × 1019 at cm−3 for the P dopant and 6.4 × 1018 at cm−3 for the Sb dopant. The activated electron concentration was found to be up to 4.1019 cm−3 in the Ge film. A gain of photoluminescence (PL) intensity three times higher than the sample doped only with P atoms was obtained. This result contributes to the perspective that Ge films can be utilized in functional optoelectronic as well as photonic devices. [ABSTRACT FROM AUTHOR]

In this letter, we present an experimental investigation on electrical properties of lateral IGBTs (LIGBTs) under an uniaxial mechanical strain for the first time. Both ON-state and turn-off characteristics of LIGBT under an uniaxial strain are studied extensively. The uniaxial strain is applied both parallel and perpendicular to the channel direction. The uniaxial tensile strain will increase the collector current (${I} _{C}$) and the uniaxial compressive strain will decrease the ${I} _{C}$ , while the breakdown voltage (${V} _{\textit {BD}}$) is not affected. The parallel strain and perpendicular strain affect the ${I} _{C}$ distinctly in both the linear and saturation regions. The piezoresistance coefficient of LIGBT under the parallel strain is more than three times that of nMOSFET in the linear region. The parallel tensile strain declines the ON-state voltage drop (${V} _{ \mathrm{\scriptscriptstyle ON}}$) and increases the turn-off time (${t} _{ \mathrm{\scriptscriptstyle OFF}}$) and turn-off loss (${E} _{ \mathrm{\scriptscriptstyle OFF}}$). While the perpendicular tensile strain decreases the ${V} _{ \mathrm{\scriptscriptstyle ON}}$ , ${t} _{ \mathrm{\scriptscriptstyle OFF}}$ , and ${E} _{ \mathrm{\scriptscriptstyle OFF}}$ simultaneously, which is extremely beneficial for real applications. The mechanisms of these strain effects are studied. [ABSTRACT FROM AUTHOR]

Increasing findings suggest that demyelination may play an important role in the pathophysiology of brain injury, but the exact mechanisms underlying such damage are not well known. Mechanical tensile strain of brain tissue occurs during traumatic brain injury. Several studies have investigated the cellular and molecular events following a static tensile strain of physiological magnitude on individual cells such as oligodendrocytes. However, the pathobiological impact of high-magnitude mechanical strain on oligodendrocytes and myelinated fibers remains under investigated. In this study, we reported that an applied mechanical tensile strain of 30% on mouse organotypic culture of cerebellar slices induced axonal injury and elongation of paranodal junctions, two hallmarks of brain trauma. It was also able to activate MAPK-ERK1/2 signaling, a stretch-induced responsive pathway. The same tensile strain applied to mouse oligodendrocytes in primary culture induced a profound damage to cell morphology, partial cell loss, and a decrease of myelin protein expression. The lower tensile strain of 20% also caused cell loss and the remaining oligodendrocytes appeared retracted with decreased myelin protein expression. Finally, high-magnitude tensile strain applied to 158N oligodendroglial cells altered myelin protein expression, dampened MAPK-ERK1/2 and MAPK-p38 signaling, and enhanced the production of reactive oxygen species. The latter was accompanied by increased protein oxidation and an alteration of anti-oxidant defense that was strain magnitude-dependent. In conclusion, mechanical stretch of high magnitude provokes axonal injury with significant alterations in oligodendrocyte biology that could initiate demyelination. [ABSTRACT FROM AUTHOR]

Children randomised in the neonatal period to high frequency oscillatory ventilation (HFOV) or conventional mechanical ventilation (CMV) in the United Kingdom Oscillation study (UKOS) had superior lung function at 11 to 14 years of age. During HFOV, much smaller tidal volumes, but a higher mean airway distending pressure is delivered, hence, a possible explanation for a volume dependent effect on long term lung function could be an increase in inflammation in response to higher tidal volumes and strains. We tested that hypothesis by assessing interleukin-6 (IL-6) and -8 (IL-8) release from A549 alveolar analogue cells following biaxial mechanical strain applied at 0.5 Hz occurring during conditions mimicking strain during CMV (5–20% strain) and conditions mimicking strain during HFOV (17.5% ± 2.5% strain) for up to 4 h. Cyclic strain of 5–20%, occurring during CMV, increased levels of both IL-6 and IL-8 compared to unstrained controls, while 17.5% ± 2.5% strain, occurring during HFOV, was associated with significantly lower levels of IL-6 (46.31 ± 2.66 versus 56.79 ± 3.73 pg/mL) and IL-8 (1340.2 ± 74.9 versus 2522 ± 248 pg/mL) secretion compared to conditions occurring during CMV at four hours. These results may provide a possible explanation for the superior lung function in 11–14-year-old children who had been supported in the neonatal period by HFOV. [ABSTRACT FROM AUTHOR]

• An approach to investigate effect of continuous tensile strain on PV performance. • Critical strains for a-Si and organic PV cells are determined. • Existing test methods and results are compared and discussed. • Effects of elevated temperatures on electrical performance of PV cells are investigated. Building integration using thin-film flexible photovoltaic (PV) cells with load-carrying structures requires understanding of their electrical performance under continuous mechanical loadings. Limited results mainly focus on the electrical performance of PV cells under certain fixed mechanical strains. In this paper, an approach is examined to continuously apply tensile strains on PV cell specimens; therefore the short circuit current (I SC) and open circuit voltage (V OC) are constantly monitored. Two types of PV cells are studied under the proposed approach including amorphous silicon (a-Si) and organic PV cells and the results demonstrate its practicability to determine the critical tensile strains reliably for both PV types. It is found that V OC is more sensitive than I SC to the applied tensile strain for both types of PV cells and substantial degradation in V OC for a-Si cells initiates at the tensile strain of 1.51%. For organic cells, significant reduction in V OC is observed at the critical tensile strain of 1.46% in association with yielding of the substrate. While noticeable degradation can be only observed in I SC from 1.67% strain for a-Si PV cells and from 3.09% strain for organic ones. In addition, linear declines with temperature in V OC of both PV types are quantified for temperatures over 30 °C. [ABSTRACT FROM AUTHOR]

Highlights • Investigation of magnetic properties of GaMnAsP films with two different thicknesses. • The Curie temperature was higher in thicker GaMnAsP layer. • Annealing increases the Curie temperature of GaMnAsP layers. • The out-of-plane magnetic anisotropy becames stronger after annealing. • 3-D magnetic anisotropy energy diagrams show easy axes of GaMnAsP films. Abstract We have investigated the magnetic properties of ferromagnetic semiconductor GaMnAsP films with two different thicknesses. Temperature scans of the resistance revealed that the Curie temperature was higher in the 50-nm GaMnAsP layer than in the 16-nm layer, and was increased in both layers after annealing. The Hall effect was measured during the magnetization reversal process to identify the anisotropy of the films. The hysteresis observed from the as-grown samples in anomalous Hall resistance measurements implied the presence of out-of-plane magnetic anisotropy in both samples. The out-of-plane magnetic anisotropy in both samples became much stronger after thermal annealing. Quantitative values of the magnetic anisotropy of the GaMnAsP films were obtained from angular dependent Hall effect measurements. By constructing magnetic anisotropy energy diagrams for the films, we clearly show the change of magnetic anisotropy depending on the film thickness and thermal annealing in GaMnAsP films. [ABSTRACT FROM AUTHOR]

Highlights • Ordinary river sand with a maximum size of 4750 µm is selected in this study. • The strain of river sand ECC (s/b = 0.55) is more than 9%. • The compressive strength of river sand ECC is from 45 MPa to 63.65 MPa. • When mechanical properties is the same, the cost in rive sand ECC decreases by 10%. • River sand ECC can achieve great mechanical properties and good economy. Abstract Conventional engineered cementitious composites (ECCs) are produced with low-volume and expensive ultrafine silica sand (maximum size 250 µm), which imposed negative influence on dry-shrinkage, cost and the practical application of ECC. In this study, an economical ultra-high ductile engineered cementitious composite featuring large-particle and high-volume ordinary river sand (RS) is developed. The gradation of ordinary river sand is consistent with that of fine aggregate in traditional concrete and its maximum size (4750 µm) is almost 20 times that of ultrafine silica sand (USS) in traditional ECC. Price of RS is about 1/30 of that of USS. The experimental results show that all river-sand ECCs (RS-ECC) present the strain-hardening and multiple-crack phenomena. Especially, the average tensile strain of RS-ECC with maximum sand size of 4750 µm and a sand/binder ratio of 0.55 is over 9%. Meanwhile, the cost of composites is reduced by more than 10%. The pseudo strain-hardening (PSH) indices of RS-ECCs are more than 30, which indicates that replacing USS with high-volume and large-particle RS in ECC is sufficient to meet the requirement of the ultra-high ductility although the use of RS increases the fracture toughness and decreases the fiber bridging complementary energy. [ABSTRACT FROM AUTHOR]

Abstract Deuterium exchange combined with near infrared (NIR) spectroscopy was used to study the roles of accessible and inaccessible cellulose in the load transfer of eucalyptus wood. Monitoring the drying process helped to assign NIR bands of deuterated wood samples. Polarized NIR spectra of protonated and deuterated samples confirmed that inaccessible hydroxyl groups in eucalyptus wood were preferably oriented in the longitudinal direction. The spectral changes on NIR spectra caused by mechanical strain could be highlighted by averaging loading and unloading cycles to compensate for effects of desorption and isotope re-exchange due to environmental fluctuations. After deuteration, the bands affected by mechanical strain at around 6420, 6240 and 4670 cm−1, which had been assigned to hydroxyl groups in cellulose, remained at these positions, suggesting the inaccessible cellulose fraction was the main load-bearing component in wood. A small band at around 4700 cm−1 responding to mechanical strain, becoming visible in the deuterated spectra, indicated that accessible hydroxyls also contributed to the load transfer. Furthermore, the measurements confirmed previous reports of moisture adsorption of wood under tensile stress. Graphical Abstract Unlabelled Image Highlights • NIR spectroscopy can be used to monitor molecular strain in air-dry wood. • Inaccessible/crystalline cellulose fraction was the main load-bearing structure in wood. • Accessible hydroxyls were less involved in the load transfer. • Tensile stress was found to induce moisture adsorption of wood. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Pmmn -ZrS 2 monolayer is a quasi direct semiconductor. • Pmmn -ZrS 2 monolayer is energetically, kinetically, and thermally stable. • Using PBE (HSE06 hybrid functional) level of theory, Pmmn -ZrS 2 exhibits a direct band gap of 0.53 eV (1.53 eV). • The band gap of Pmmn -ZrS 2 can be effectively modified by strain effects. Abstract A new 2D stable crystal of zirconium-sulfur compound namely Pmmn -ZrS 2 monolayer by using density functional theory is predicted. Our computations confirm that our proposed ZrS2 monolayer indicates good energetic, kinetic, and thermal stabilities as proved by the crystal energy analysis, phonon modes computation, and the molecular dynamic assessment respectively. Investigation in its electronic properties shows the new Pmmn -ZrS 2 monolayer is a quasi direct semiconductor with a band gap of about 1.53 eV obtained by HSE06 hybrid functional method can be modulated by external in-plane strain effects. These results suggest this monolayer as a useful material for application in nano-electronic devices. [ABSTRACT FROM AUTHOR]

Flexible zinc oxide thin film transistors (ZnO TFTs) with a mobility of $ {13}~\text {cm}^{2}/\text {V}\cdot \text {s}$ and an I $_{\text {on}}/\text{I}_{\text {off}}$ ratio of $ {1.5}\times {10}^{8}$ have been fabricated on polyimide substrate, where the ZnO channel is deposited by atomic layer deposition (ALD) at 140 °C. High bending stability has been achieved due to excellent interface quality between alumina (Al2O3) dielectric and ZnO channel with a sharp interface topography. The flexible ZnO device exhibits excellent electrical characteristics even after being bent for 200 000 cycles with a tensile strain of 0.63%. Electrical measurement under a high tensile strain of 2.08% has also been carried out. Moreover, the electrical performance dependence of flexible ZnO TFTs with a tensile strain of 0.78% on temperature from 20 °C to 140 °C has been investigated for the first time. [ABSTRACT FROM AUTHOR]

Abstract The mechanism underlying the development of osteoarthritis induced by high tensile strain is unclear. In this study, the effects of different degrees of mechanical tensile strain stimulation on Sprague–Dawley rat chondrocytes were explored. Rat chondrocytes were subjected to mechanical tensile strain at different intensities and frequencies (control group, low tensile strain group, intermediate tensile strain group, and high tensile strain group) using a self-made in vitro tensile strain device. After applying mechanical tensile strain, chondrocytes were collected to detect the expression of collagen II, Aggrecan, matrix metalloproteinase 13 (MMP13), ADAMTS5, and uncoupling protein 2 (UCP2) by real-time quantitative PCR and western blotting as well as reactive oxygen species (ROS) by fluorescence probes. Mechanical tensile strain at different frequencies and intensities had different effects on the biological functions of chondrocytes. Compared with the control group, the expression levels of Col II and Aggrecan in the low and intermediate tensile strain groups increased significantly, while the expression of MMP13 and ADAMTS5 decreased. There were no significant differences between the low and intermediate tensile strain groups. Col II and Aggrecan levels were significantly lower in the high tensile strain group than in the control group, while MMP13 and ADAMTS5 levels were higher. There were no significant differences in ROS production between the low and intermediate tensile strain groups and the control group, but the high tensile strain group exhibited significantly increased ROS production. The expression of UCP2 was significantly lower in the high tensile strain group than in all other groups. These results showed that stimulation with different levels of mechanical tensile strain has different effects on chondrocytes. Repeated high tensile strain promoted the anabolic function of chondrocytes, increased ROS production, and decreased UCP2. These results provide a potential mechanism by which osteoarthritis is induced by high mechanical tensile strain. [ABSTRACT FROM AUTHOR]