Neutral Plane Research Articles

The Functional Role of Colloquial Syntax Elements in Tatyana Tolstaya’s Novel <i>Kys</i>’

The article deals with a contextual analysis of one chapter in the novel Kys by Tatyana Tolstaya, a contemporary Russian writer. The linguistic peculiarity of this work is shown together with the importance and role of certain elements of colloquial syntax (such as incomplete sentences, syntactic parallelism, rhetorical questions, repeats, etc.). Specific ways and techniques of transforming syntactic units from a neutral plane of an utterance to an expressively emotional one are revealed on concrete examples. Arguments are provided that the functions of the colloquial syntax elements in the novel are to create a comical effect, to strengthen the emotionality of both the characters and the text in general, to organize the speech rhythm, as well as to reveal both the protagonists inner world and an aesthetic atmosphere of this unusual work.

Neutral Mechanical Plane Shifting in Bending Elastomer Film Revealed by Quantification of Internal Strain

Flexible electronic devices composed of soft materials, such as polymers and elastomers, require high mechanical durability to maintain their performance during cyclic bending, where large bending can lead to fracture. To design the appropriate structure for such devices, it is essential to utilize a neutral mechanical plane (NMP) in which the strain becomes zero inside bending materials. Despite the importance of identifying the NMP position for this utilization, the NMP position in soft materials has rarely been studied experimentally because of the difficulty in measuring internal strain in largely bending materials. Herein, the NMP position of bending polydimethylsiloxane (PDMS) film, which is a common soft material used in flexible electronic devices, is experimentally quantified via internal strain measurement with a cholesteric liquid crystal sensor. This is the first reported identification of the NMP position, revealing that bending of the PDMS film reversibly shifts the NMP position within ≈11% of the film thickness toward the inner bending surface. Considering this large NMP shift, a flexible electronic device with high mechanical durability is fabricated. The direct identification of the NMP position, which is enabled by the internal strain measurement, facilitates the development of device designs for flexible electronic devices.

Outward- and inward-distinguishable bending sensor with silver nanowires sandwiched between polydimethylsiloxane layers

A bending sensor having a structure in which silver nanowires (AgNWs) are located between polydimethylsiloxane (PDMS) layers, which can distinguish outward bending and inward bending directions, was fabricated. As the absolute value of curvature increased during outward bending, the relative change in resistance increased, and at a curvature of 0.24 mm−1, it increased by 36% compared to the flat state. In inward bending, the relative change in resistance decreased as the curvature increased. In order to analyze the reason for the opposite resistance change depending on the bending direction, the birefringence of the PDMS polymer during bending was measured using the Stokes polarimetry method. Due to the different locations of the neutral plane with the asymmetric position of the AgNWs, the PDMS polymers were aligned differently. The opposite resistance change during outward and inward bending could be explained as the effect of the different realignments of the AgNWs imprinted by the PDMS polymers.

Width-bending characteristic of REBCO HTS tape and flat-tape Rutherford-type cabling

The width-bending behaviors for a rare earth barium copper oxide (REBCO) high-temperature superconducting (HTS) tape have been investigated. It has been found experimentally that the width-bending strain of a Yttrium Barium Copper Oxide (YBCO) tape does not degrade the critical current as much as is expected from the axial strain. The critical current is not directly affected by the width-bending strain but by the axial strain, which the width-bending strain generates by the Poisson effect. Since Poisson’s ratio is about 0.3, the axial strain effective on the critical current is about 30% of the width-bending strain. Therefore, the width-bending strain of even 1.5% degrades the critical current by only 15% if the REBCO layer side is bent inward. However, the critical current degraded by more than 70% when the REBCO layer is outward. The width-bending effects on the critical current have been further examined, considering Poisson’s ratio changes and the neutral plane shift of the REBCO tape substrate. Those changes would occur when the material yields due to severe width-bending. Based on the width-bending of REBCO tapes, flat-tape Rutherford-type cabling is discussed. A REBCO Rutherford-type cable can provide various advantages, especially for narrow-tape cabling. The flat-tape Rutherford-type cable has better characteristics against an electromagnetic transverse Lorentz force. Furthermore, the tape length of the cable can be approximately the same as the cable length allowing for excellent tape usage. REBCO Rutherford-type cabling will be a promising high-current, high-field cabling method using thin substrate REBCO tapes. It will be useful for AC ramp-field and pulse-field applications with low AC losses and low shield currents. It notes that the filaments in the cable are symmetrically distributed in parallel. Therefore, each filament’s inductance is uniform, and a uniform current distribution among the filaments can be obtained.

MMS Observations of Super Thin Electron‐Scale Current Sheets in the Earth's Magnetotail

AbstractFlapping of the current sheet (CS) associated with the propagation of high‐velocity bulk flows allowed to observe the super thin current sheet (STCS) in the magnetotail plasma sheet (PS). During the interval of interest, 111 crossings of the CS neutral plane were detected. In 95 crossings, the STCSs with a current density J ≥ 20 nA/m2 were observed. A half‐thickness (LSTCS) of the STCSs was about a few electron gyroradii or less. In a number of the STCSs the parameter of adiabaticity (κe) was <1.0 for suprathermal electron population (>1 keV). Our analysis has shown that the electric current in such STCSs is carried by unmagnetized electrons (κe < 1), and the stress balance is supported by the off‐diagonal terms of their pressure tensor. In this sense, the underlying physics of the formation of STCSs at electron scales by unmagnetized electrons is similar to the mechanism of ion‐scale thin CS formation by the quasi‐adiabatic ions. The low‐energy population of magnetized electrons is also crucially important since it keeps the STCS stable and allows their observation as a quasi‐stationary structure. We compare the observed half‐thickness of the STCS with that predicted by a new kinetic theory (λ) considering the coupling between ion‐scale TCS and electron‐scale STCS. We found a reasonable agreement between both values: LSTCS ∼ (0.3–1)λ. Further improvement in the theory taking into account the dynamics of unmagnetized electrons may provide better agreement with observations.

New insight into the radial forging process by an asymptotic-based axisymmetric analysis

In this paper, an analytical approach based on the asymptotic analysis is proposed to develop an axisymmetric model for the radial forging process of rods. This model is able to predict the deformation inhomogeneity in the radial direction and approves that the profile of the neutral plane is not a planar cross section of the workpiece. For the first time, a relationship has been developed between the die angle, friction coefficient and back-push stress that can be used as a criterion for examining the feasibility of the radial forging process. A breakthrough method has also been proposed that can effectively find the location of the neutral plane far easier and faster than the traditional approach. Finite element simulation of the process has been performed to validate the deformation pattern obtained by the asymptotic model. Models are also verified against available experimental data. The findings of this study are especially useful for online design, analysis and control of the radial forging process.

Enhancing the shape memory effect of Cu–Al–Ni alloys via partial reinforcement by alumina through selective laser melting

Cu–Al–Ni shape memory alloys (SMAs) have high thermal stability and various potential applications. The most significant factors limiting their application are their relatively low elastic strain and poor shape memory effect known as recoverable strain. In addition, the incorporation of new elements for reinforcement usually results in a polycrystalline structure with a larger grain size, which is not suitable for shape memory applications. To overcome these drawbacks, a new method is introduced in this study to increase the shape memory effect and its stability in Cu–Al–Ni SMAs through partial reinforcement with alumina (Al2O3) by selective laser melting. In this approach, the reinforcing lines are deposited in-plane at the mid-height of the printed part, i.e., in the neutral plane. To characterize the effect of partial reinforcement, partially reinforced parts with 0.3 wt% and 0.9 wt% Al2O3 are compared to fully reinforced parts. The results show that the accumulation of localized residual compressive stresses above the reinforcing lines in the neutral plane, induced during selective laser melting, increases the shape memory effect as a result of the increase in mechanical anisotropy in the building direction. Moreover, a new phenomenon named the “waistband effect” is observed in cyclic compressive operation, which results in incremental penetration of the reinforcing particles into the neutral plane during compression. This facilitates a higher strain recovery in the partially reinforced part. These results clearly confirm that partial reinforcement with Al2O3 significantly enhances the shape memory effect of Cu–Al–Ni SMAs.

Evaluation of Negative Skin Friction on Bridge Abutment Piles

Piles are used to transfer loads of structures to deeper and stronger soil layers through skin friction and/or end bearing. Surcharge loads, site grading, or dewatering may induce downward movement of soil adjacent to piles installed in a compressible medium. This movement creates negative skin friction stresses acting downward at the pile-soil interface, which applies additional loads “drag forces” to the pile causing a maximum axial load in the pile shaft at the “neutral plane”. To evaluate the development of drag forces, a comprehensive field monitoring program was conducted over four years for three instrumented abutment H-piles as part of a three-span bridge project. The soil settlement and changes in pore water pressure in the soil adjacent to the piles due to the construction of an approach embankment were monitored using multiple-point extensometers and vibrating wire piezometers. The piles’ elastic settlement and strains were measured using single-point extensometers and vibrating wire strain gauges. The field measurements are presented and discussed in terms of responses time histories and load distribution along one pile shaft. In addition, the calculated forces from vibrating wire strain gauges are compared with the unified design method prediction considering the total stress method (α-method) for cohesive soils. The results show that the maximum drag force was developed after the complete dissipation of excess pore water pressure and that the location of neutral plane varied during the embankment construction stages. Employing the total stress method in the unified design method provided a reasonable prediction of the drag force and the neutral plane’s location.

Validation of CFD fire model pressure predictions for modern residential style structures

Controlled gas burner experiments were conducted in single- and two-story residential style structures instrumented with pressure transducers, thermocouples, and bi-directional probes throughout the structures. Exterior doors and window openings were vented in a controlled sequence to investigate the effect of the resulting flow paths on fire-induced flow dynamics and thermal conditions in the structures. The data collected in these experiments provides validation cases for the fire modeling community which currently lacks full-scale data from experiments in realistic residential style structures. The Fire Dynamics Simulator was used to model each scenario in a validation exercise that also investigated the sensitivity of the pressure predictions to the model parameters. The model was capable of predicting the qualitative changes in pressure measurements due to ventilation events as well as the apparent elevation of the neutral plane. Peak pressures were predicted to within 6% on average and quasi-steady static pressures were predicted to within 24% on average. The mean instantaneous error between the experimental pressures and those predicted with the “Localized Leakage” method was approximately 53% compared to 67% with the “Pressure Zone Leakage” method prior to the first ventilation event.

On the Presence and Thermalization of Cold Ions in the Exhaust of Antiparallel Symmetric Reconnection

Using fully kinetic 2.5 dimensional particle-in-cell simulations of anti-parallel symmetric magnetic reconnection, we investigate how initially cold ions are captured by the reconnection process, and how they evolve and behave in the exhaust. We find that initially cold ions can remain cold deep inside the exhaust. Cold ions that enter the exhaust downstream of active separatrices, closer to the dipolarization front, appear as cold counter-streaming beams behind the front. In the off-equatorial region, these cold ions generate ion-acoustic waves that aid in the thermalization both of the incoming and outgoing populations. Closest to the front, due to the stronger magnetization, the ions can remain relatively cold during the neutral plane crossing. In the intermediate exhaust, the weaker magnetization leads to enhanced pitch angle scattering and reflection. Cold ions that enter the exhaust closer to the X line, at active separatrices, evolve into a thermalized exhaust. Here, the cold populations are heated through a combination of thermalization at the separatrices and pitch angle scattering in the curved magnetic field around the neutral plane. Depending on where the ions enter the exhaust, and how long time they have spent there, they are accelerated to different energies. The superposition of separately thermalized ion populations that have been accelerated to different energies form the hot exhaust population.

Case study of post uplift in deep excavation of a subway station in thick soft clay using long pile foundations

There is growing engineering concern about the base heave and post uplift phenomena in deep excavation in soft clay, which may pose a risk of instability of retaining systems. The purpose here is to conduct a detailed case study on the post uplift observed in a 17.6-meter-deep braced excavation of a subway station in thick soft clay (total thickness up to 42 m) in Shanghai. In this case, a large uplift up to 87 mm unexpectedly developed for the post founded on a 30-meter-long pile foundation. Efforts were first made to examine the complex relationships between the post uplift with the excavation depth (H), Terzaghi’s safety factor against base heave (Fs) and maximum deflection of retaining wall. A simplified approach for soil-post-strut interaction analysis was then proposed and used for quantitative research. The working characteristics of the long pile foundation under low safety factor against base heave (Fs < 1.5) are summarized as following: (a) the back-analyzed neutral plane, where soil uplift equals the post uplift, lies at approximately 0.68 times the pile length from the pile top; (b) deep soil movement below the neutral plane results in the observed post uplift; (c) strut reaction plays a minor role in the restriction of post uplift. The influence of base treatment and excavation/construction procedures on post uplift and the principles of pile foundation design are also discussed in this paper.

A Bioinspired Stretchable Sensory-Neuromorphic System.

Conventional stretchable electronics that adopt a wavy design, a neutral mechanical plane, and conformal contact between abiotic and biotic interfaces have exhibited diverse skin-interfaced applications. Despite such remarkable progress, the evolution of intelligent skin prosthetics is challenged by the absence of the monolithic integration of neuromorphic constituents into individual sensing and actuating components. Herein, a bioinspired stretchable sensory-neuromorphic system, comprising an artificial mechanoreceptor, artificial synapse, and epidermal photonic actuator is demonstrated; these three biomimetic functionalities correspond to a stretchable capacitive pressure sensor, a resistive random-access memory, and a quantum dot light-emitting diode, respectively. This system features a rigid-island structure interconnected with a sinter-free printable conductor, which is optimized by controlling the evaporation rate of solvent (≈160% stretchability and ≈18550 S cm-1 conductivity). Devised design improves both areal density and structural reliability while avoiding the thermal degradation of heat-sensitive stretchable electronic components. Moreover, even in the skin deformation range, the system accurately recognizes various patterned stimuli via an artificial neural network with training/inferencing functions. Therefore, the new bioinspired system is expected to be an important step toward implementing intelligent wearable electronics.

Bauschinger effect and latent hardening under cyclic micro-bending of Ni-base Alloy 718 single crystals: Part I. Experimental analysis of single and multi slip plasticity

Cyclic micro-bending tests on fcc single crystal Ni-base Alloy 718 cantilevers with different crystal orientations were performed to analyze the influence of activated slip systems on dislocation plasticity, latent hardening and the Bauschinger effect. The investigations indicate that plasticity in single crystal micro-cantilevers is significantly influenced by two phenomena - dislocation interaction and dislocation pile-up at the neutral plane. Both phenomena occur at the same time. Their ratio seems to be determined by the activated slip systems. Slip trace analysis indicates that the activation of only one slip system leads to a strong localization of plasticity to a limited number of parallel slip bands. This results in low dislocation interaction and consequently pronounced pile-ups at the neutral plane. In multi slip orientation, the second slip system leads to activation of significantly more dislocation sources, causing a much earlier and more homogeneous elastic-plastic transition zone. In stress-strain hysteresis loops during bending, pronounced dislocation interaction in multi slip orientation leads to a more pronounced latent hardening. The results suggest that on a microstructural length scale, plasticity behavior is strongly affected by activated slip systems, which determine local dislocation phenomena. Based on the results presented in this paper, a finite element analysis of latent hardening and the Bauschinger effect using a single crystal plasticity model with latent kinematic hardening is presented in Part II.

Effect of Mechanical Properties of Substrates on Flexibility of Ag Nanowire Electrodes under a Large Number of Bending Cycles

Ag nanowire electrodes have attracted considerable attention because of their potential applications in next-generation flexible electronics. However, there is a paucity of studies on the mechanical properties of Ag nanowire electrodes subjected to a large number of bending cycles. In this study, the effects of the substrate on the mechanical behavior of Ag nanowire electrodes were studied for a high bending frequency. The mechanical reliability of the Ag nanowire electrodes fabricated on a polyethylene terephthalate (PET) substrate was better than that for a polyimide (PI) substrate; the increase in the resistance of the PET-based Ag nanowire electrode was 1.07%, while that of the PI-based one was 1.23%. Nanoindentation tests showed that the elastic modulus of PI was larger than that of PET. This resulted in a lower bending strain on PET-based Ag nanowire electrodes compared to those on PI-based ones, because of the smaller distance from the neutral plane of the PET-based system. Our study showed that the mechanical properties of the substrate influenced the strain imposed on the thin layer on the substrates, which, in turn, determines the mechanical reliability of the thin-layer/substrate multilayer system.

Influence of veil interleave distribution on the delamination resistance of cross-ply CFRP laminates under low velocity impact

This paper focuses on the influence of polyphenylene sulfide (PPS) veil distribution within unidirectional carbon fibre reinforced polymer (CFRP) laminates under low velocity impact (LVI). Tests were conducted on a baseline layup of (0/90)7s, modified with various levels of veil interleaving at the middle or the outer plies. The results demonstrate that veil interleaving can reduce and migrate the damage from predominantly inter-laminar to intra-laminar for veils positioned in the outer plies. The interleaved configurations also display differences in the impact stiffness [1] after the Delamination Threshold Load (DTL), implying the level of damage is lower than those with fewer veils and those positioned at the mid-level neutral plane. Interesting changes in the impact force history are also observed where a smoothing effect around the DTL is achieved through interleaving. Fracture migration effects are also considered and provide a significant insight into the damage characteristics when using CFRP laminates with interleaved PPS veils under LVI.

Thermal buckling of functionally graded piezomagnetic micro- and nanobeams presenting the flexomagnetic effect

Galerkin weighted residual method (GWRM) is applied and implemented to address the axial stability and bifurcation point of a functionally graded piezomagnetic structure containing flexomagneticity in a thermal environment. The continuum specimen involves an exponential mass distributed in a heterogeneous media with a constant square cross section. The physical neutral plane is investigated to postulate functionally graded material (FGM) close to reality. Mathematical formulations concern the Timoshenko shear deformation theory. Small scale and atomic interactions are shaped as maintained by the nonlocal strain gradient elasticity approach. Since there is no bifurcation point for FGMs, whenever both boundary conditions are rotational and the neutral surface does not match the mid-plane, the clamp configuration is examined only. The fourth-order ordinary differential stability equations will be converted into the sets of algebraic ones utilizing the GWRM whose accuracy was proved before. After that, by simply solving the achieved polynomial constitutive relation, the parametric study can be started due to various predominant and overriding factors. It was found that the flexomagneticity is further visible if the ferric nanobeam is constructed by FGM technology. In addition to this, shear deformations are also efficacious to make the FM detectable.

Effectiveness and petroleum geological significance of tectonic fractures in the ultra-deep zone of the Kuqa foreland thrust belt: a case study of the Cretaceous Bashijiqike Formation in the Keshen gas field

The buried depth of the gas-producing reservoir in the Kuqa foreland thrust belt of the Tarim Basin exceeds 6000 m. The average matrix porosity of the reservoir is 5.5%, and the average matrix permeability is 0.128 × 10−3 μm2. In order to reveal the characteristics and effectiveness of ultra-deep fractures and their effects on reservoir properties and natural gas production, outcrops, cores, thin section, image logs and production testing data are used to investigate the effectiveness of tectonic fractures in ultra-deep reservoirs in the Kuqa foreland thrust zone, and the corresponding geological significance for oil and gas exploration and development are discussed. Tectonic fractures in the thrust belt include EW-trending high-angle tensile fractures and NS-trending vertical shear fractures. The former has a relatively high filling rate, while the latter is mostly unfilled. Micro-fractures are usually grain-piercing-through cracks with width of 10–100 microns. In the planar view, the effective fractures are concentrated in the high part and wing zones of the long axis of the anticline, and along the vertical direction, they are mainly found in the tensile fracture zone above the neutral plane. The adjustment fracture zone has the strongest vertical extension abilities and high effectiveness, followed by the nearly EW longitudinal tensile fracture zone, and the netted fracture zone with multiple dip angles. The effectiveness of fracture is mainly controlled by fracture aperture and filling degrees. Effective fractures can increase reservoir permeability by 1–2 orders of magnitude. The higher part of the anticline is associated with high tectonic fracture permeability, which control enrichment and high production of natural gas. The netted vertical open fractures effectively communicate with pores and throats of the reservoir matrix, which forms an apparent-homogenous to medium-heterogeneous body that is seen with high production of natural gas sustained for a long term.

Nonlinear in-plane buckling of fixed shallow arches with an orthotropic thin-walled section under uniform radial and thermal loading

This paper presents a comprehensive investigation of nonlinear in-plane buckling of fixed shallow arches with an orthotropic thin-walled section under uniform radial and thermal loading. For convenience of analysis, the stretching–bending coupling within section internal forces is decoupled by utilizing a neutral plane concept. The principle of minimum total potential energy in conjunction with the first-order shear deformation theory is used to derive the differential equation of equilibrium and the buckling equation and a modified slenderness ratio is proposed to govern the buckling behaviors of laminated arches. The closed-form solutions for the limit point buckling and bifurcation buckling are obtained. Effects of environment temperature increases and the stacking sequences on the buckling load are discussed in detail. Comparisons with finite elements results show that the presented analytical solution can precisely predict the nonlinear behaviors of thin-walled laminated arches.

Two-Year Outcomes After Total Ankle Replacement With a Novel Fixed-Bearing Implant.

The Integra Cadence total ankle replacement (TAR) is a fourth-generation anatomic, fixed-bearing implant requiring minimal tibial and talar resection, which has been in clinical use since June 2016. The primary purpose of this study is to assess its short-term clinical and radiographic outcomes after TAR using this prosthesis. This is a prospective case series of consecutive patients that underwent TAR using this novel fourth-generation prosthesis between June 2016 and November 2017. The primary outcome of interest was the Ankle Osteoarthritis Scale (AOS). Secondary outcomes included Short Form Health Survey-36 (SF-36) scores, radiographic alignment, complications, reoperations, and revisions. In total, 69 patients were included in our study. Fifty-one patients (73.9%) required a total of 91 ancillary procedures. Postoperatively, AOS pain scores decreased significantly by an average of 17.8±30.1 points from 45.9±18.2 to 28.4±27.3 (P < .001). AOS disability scores also decreased significantly following surgery by an average of 22.0±30.5 points from 53.9±18.5 to 32.5±27.9 (P < .001). The SF-36 physical component summary score improved 10.4±9.8 points from 33.1±9.1 to 42.6±9.1 (P < .001). Radiographic analysis demonstrated significant improvement to neutral coronal plane alignment, which was achieved in 97% of patients (P < .01) with no cyst formation at 2 years. There was 1 reported complication, 9 reoperations, and no metal or polyethylene component revisions. Overall, the 2-year implant survivorship was 100% in our cohort. Eighteen patients (26.1%) demonstrated fibrous ingrowth of the tibial component. However, outcome scores for these patients did not demonstrate any negative effects. In our hands, this TAR system demonstrated excellent early clinical and radiographic outcomes. Patients reported improved physical health status, pain, and disability in the postoperative period. Total ankle instrumentation allowed for accurate and reproducible implantation with correction of coronal and sagittal plane deformities. Early results for the clinical use of this TAR system are promising, but further long-term prospective outcome studies are necessary. Level IV, case series.

Algorithmic Improvements to Finding Approximately Neutral Surfaces

AbstractInterior oceanic motions occur predominantly along, rather than across, the neutral tangent plane. These planes do not link together to form well‐defined surfaces, so oceanographers use approximately neutral surfaces. To date, the most accurate such surface is the ω‐surface, but its practical utility was limited because its numerical implementation was slow and sometimes unstable. This work upgrades the speed, robustness, and utility of ω‐surfaces. First, we switch from solving an overdetermined matrix problem by minimal least squares, to solving an exactly determined matrix problem, obtained either by the normal equations (multiplication by the matrix's transpose) or by discretizing Poisson's equation derived from the original optimization problem by the calculus of variations. This reduces the computational complexity, roughly from to , where N is the number of grid points in the surface. Second, we update the surface's vertical position by solving a nonlinear equation in each water column, rather than assuming the stratification is vertically uniform. This reduces the number of iterations required for convergence by an order of magnitude and eliminates the need for a damping factor that stabilized the original software. Additionally, we add “wetting” capacity, whereby incrops and outcrops are reincorporated into the surface should they become neutrally linked as iterations proceed. The new algorithm computes an ω‐surface in a 1,440 by 720 gridded ocean in roughly 15 s, down from roughly 11 h for the original software. We also provide two simple methods to label an ω‐surface with a (neutral) density value.