Edge Conditions Research Articles

Closed-Form Solution for Scale-Dependent Frequencies of Shear Deformable Cellular Microplates Coated by Piezoelectric Polymeric Skins Consisting of FG Distributed CNTs

In this work, a rectangular cellular microplate is taken into consideration which is embedded between two functionally graded carbon nanotube-reinforced composite layers that have the piezoelectric ability. Different patterns for the carbon nanotube dispersion are considered. Moreover, an external electrical voltage is applied to them. The displacements are described based on a higher-order shear deformation theory which is called hyperbolic theory and the size influence is captured via the modified couple stress formulations. The governing motion equations are then derived using the variational technique and Hamilton’s principle. Then, for simply supported edge conditions, a closed-form solution is provided. Next, it turns to validate the results in simpler states, and after that, the effect of the most prominent parameters on the results is investigated. It is observed that by increasing the external applied voltage to the face sheets, the frequencies are reduced. Also, the natural frequencies have a tendency to decrease as the dimensionless material length scale parameter increases. This study’s outcomes may help design and manufacture micro-/nano-electro systems, sensors and actuators, small-scale devices, and other engineering structures.

Scale for the assessment of mucosal wave dynamics of the free edges during stroboscopic examination: clinical validation study and analysis of results.

Identifying the mucosal wave (MW) is essential when studying the voice; however, its characterization and perceived measurement during laryngeal stroboscopy (LS) are not well defined or standardized because of the subjectivity of its interpretation. This article proposed and validated a scale that characterized and approximated MW measurement during LS, applied it to participants divided into a healthy group and groups with free edge conditions, and identified differences between them. This is a descriptive and clinical validation study of the "VASQ (Vertical axis, Anteroposterior axis, Symmetry and Quantity) mucosal wave score" scale based on stroboscopy images of 137 adult men and women divided into a control group and functional and organic pathology groups. The images were analyzed by three evaluators according to an established protocol. Measurements dictating the reproducibility and validity criteria as well as the MW score in each group were obtained. The reliability of the scale was α = 0.90, internal consistency success rate was 91%, intra-observer reliability was 0.83, inter-observer reliability was 0.83, content validity coefficient was 0.92, and factor loading was 0.37-0.53. The MW total score values between 5 and 6 were established as a reference for normality (P < 0.05). Organic pathology showed lower MW score values (P < 0.05), and functional pathology to a lesser extent (P > 0.05). The proposed scale is a consistent, valid, and reliable tool. Its widespread application would favor commonly used terminology and facilitate quantitative comparisons in future studies.

Annular sector plates made of FG graphene origami-enabled auxetic metamaterial under bending and buckling loading: A VDQ-based approach

The behaviors of annular sector plates made of functionally graded graphene origami-enabled auxetic metamaterials (FG-GOEAMs) under the action of buckling and bending loads are investigated herein using a numerical approach. Multiple GOEAM layers with graphene origami (GOri) content are considered for the plate which changes in layer-wise patterns. Moreover, the material properties of the plate are calculated using novel genetic programming-assisted micromechanical models. In order to derive the governing equations, the Mindlin plate theory in conjunction with Hamilton’s principle is utilized within the framework of the variational differential quadrature (VDQ) method. The vector-matrix representation of the presented formulation can be beneficial from the viewpoint of implementing numerical approaches. The governing equations are then discretized and solved based on VDQ matrix differential and integral operators so as to obtain the critical buckling load and maximum lateral deflection of plates with different edge conditions. The effects of GOri content, folding degree and distribution pattern on the results are studied. It is revealed that increasing the GOri content leads to the negative Poisson’s ratio (NPR) effect which respectively reduces and increases the lateral deflection and the critical buckling load.

Effect of step bottom and waterway on flexural gravity wave scattering

Flexural gravity wave scattering by two semi-infinite non-identical ice sheets, which are separated by a clean water surface, is investigated in the presence of a step bottom topography. The problem is investigated in the cases of (i) intermediate water depth and (ii) shallow water. The effect of two edge conditions, (i) simply supported edge and (ii) free edge, on wave scattering is also analyzed. Employing linear velocity potential theory, the problem is studied in the frequency domain. The physical phenomenon is modeled as a boundary value problem having the Laplace equation as the governing equation, and it is solved using the eigenfunction expansion method. Considering the bottom topography and upper boundary, the fluid domain is divided into three regions, and in each region, velocity potential is expressed in terms of infinite Fourier series. Velocity and pressure are matched at the intermediate surface of two regions, and a system of algebraic equations with unknown coefficients is obtained. The complete solution of the present problem is recognized by solving the system of equations numerically. The energy relation is derived using Green's theorem. The reflection and transmission coefficients are computed and compared with the energy relation to check the accuracy of the present method. For different parameters (depth ratio, clean waterway, and different ice properties), reflection coefficient and transmission coefficient are computed and presented as a function of angular frequency. The value of the reflection coefficient ranges from zero to unity, whereas at certain frequencies, the transmission coefficient attends value more than unity.

Sloshing in a tank with elastic side walls and a membrane cover

The coupled problem of liquid sloshing in a tank with a membrane cover and elastic side walls is investigated. The velocity potential theory is used for the flow and the linear elastic theory for the cover and side walls. For the former, the vertical mode expansion is used, in which all the roots of the dispersion relationship are first found. The expansion automatically satisfies the governing equation, the tank bottom, and the tank cover conditions. The deflections of the side walls are expanded into a cosine series together with a four term polynomial, which is vital for the procedure to succeed. These expansions are then matched through the dynamic and kinematic equations of the plates, and the problem is completed by imposing the edge conditions of the plate and membrane. Through the combined matrix equation, the natural frequencies of the system are obtained. In addition, the nature of the dispersion relationship of the membrane is analyzed. Explicit solutions are obtained for some special cases, and the link with the free surface sloshing is established. Extensive numerical results are provided, and their physics is analyzed.

Characterization of the ELM-free negative triangularity edge on DIII-D

Abstract Tokamak plasmas with strong negative triangularity (NT) shaping typically exhibit fundamentally different edge behavior than conventional L-mode or H-mode plasmas. On DIII-D, every plasma with sufficiently negative triangularity ( δ &lt; δ crit ≃ − 0.12 ) is found to be inherently free of edge localized modes (ELMs), even at injected powers well above the predicted L-H power threshold. It is also possible to access an ELM-free state at weaker average triangularities, provided that at least one of the two x-points is still sufficiently negative. Access to the ELM-free NT scenario is found to coincide with the closure of the second stability region for infinite-n ballooning modes, suggesting that ballooning stability may play a role in limiting the accessible pressure gradient in NT plasmas. Despite this, NT plasmas are able to support small pedestals and are typically characterized by an enhancement of edge pressure gradients beyond those found in traditional L-mode plasmas. Furthermore, the pressure gradient inside of this small pedestal is unusually steep, allowing access to high core performance that is competitive with other ELM-free regimes previously achieved on DIII-D. Since ELM-free operation in NT is linked directly to the magnetic geometry, NT fusion pilot plants are predicted to maintain advantageous edge conditions even in burning plasma regimes, potentially eliminating reactor core-integration issues caused by ELMs.

Chemical Stability of mRNA/cDNA Complexes: Defining the Limits of mRNA Display.

Messenger RNA (mRNA) display is being increasingly adopted for peptide drug candidate discovery. While many conditions have been reported for the affinity enrichment step and in some cases for peptide modification, there is still limited understanding about the versatility of peptide-puromycin-mRNA/cDNA (complementary DNA) complexes. This work explores the chemical stability of mRNA/cDNA hybrid complexes under a range of different fundamental chemical conditions as well as with peptide modification conditions reported in an mRNA display setting. We further compare the stability of full complexes originating from two different mRNA display systems (RaPID and cDNA-TRAP). Overall, these complexes were found to be stable under a broad range of conditions, with some edge conditions benefitting from encoding directly in cDNA rather than mRNA. This should allow for more and broader exploitation of late-stage peptide modification chemistry in mRNA display, with confidence regarding the stability of encoding, and potentially better hit-finding campaigns as a result.

Core and edge modeling of JT-60SA H-mode highly radiative scenarios using SOLEDGE3X–EIRENE and METIS codes

In its first phase of exploitation, JT-60SA will be equipped with an inertially cooled divertor, which can sustain heat loads of 10 MW/m2 on the targets for a few seconds, which is much shorter than the intended discharge duration. Therefore, in order to maximize the duration of discharges, it is crucial to develop operational scenarios with a high radiated fraction in the plasma edge region without unacceptably compromising the scenario performance. In this study, the core and edge conditions of unseeded and neon-seeded deuterium H-mode scenarios in JT-60SA were investigated using METIS and SOLEDGE3X–EIRENE codes. The aim was to determine whether, and under which operational conditions, it would be possible to achieve heat loads at the targets significantly lower than 10 MW/m2 and potentially establish a divertor-detached regime while keeping favorable plasma core conditions. In first analysis, an investigation of the edge parameter space of unseeded scenarios was carried out. Simulations at an intermediate edge power of 15 MW indicate that, without seeded impurities, the heat loads at the targets are higher than 10 MW/m2 in attached cases, and achieving detachment is challenging, requiring upstream electron densities at least above 4 × 1019 m−3. This points toward the need for impurity injection during the first period of exploitation of the machine. Therefore, neon seeding simulations were carried out, performing a seeding rate scan and an injected power scan while keeping the upstream electron density at the separatrix at 3 × 1019 m−3. They show that at 15 MW of power injected into the edge plasma, the inner target is easily detached and presents low heat loads when neon is injected. However, at the outer target, the heat fluxes are not lowered below 10 MW/m2, even when the power losses in the edge plasma are equal to 50% of the power crossing the separatrix. Therefore, the tokamak will probably need to be operated in a deep detached regime in its first phase of exploitation for discharges longer than a few seconds. In the framework of core–edge integrated modeling, using METIS, the power radiated in the core was computed for the most interesting cases.

Entrepreneur's social identity, decision logic, and resource bootstrapping behaviors: An empirical study of the fsQCA method

While resource bootstrapping is widely employed by novice entrepreneurs,and social identities and decision logic are studied as important antecedents of entrepreneurs' adoption of resource bootstrapping behaviors, both scholars and practitioners have but a hazy understanding on the configuration effect of entrepreneur's social identities and decision logic on resource bootstrapping behaviors. In this paper, we combined the necessary condition analysis (NCA) and fuzzy set qualitative comparative analysis (fsQCA) to explore the configuration effects of entrepreneur's social identity and decision logic on resource bootstrapping behaviors. Analysis of 411 questionnaire date acquired from novice entrepreneurs, we found that none of single antecedent condition of both the entrepreneur's social identity and decision logic constitute the necessary condition of novice entrepreneurs' high resource bootstrapping behaviors. We also found a substitutive relationship between Darwinian social identity and communitary social identity that will lead the novice entrepreneurs with high dual effectual-causal decision logic to choose high joint utilization bootstrapping, and a complementary relationship between the three social identities of novice entrepreneurs such that those with high dual effectual-causal decision logic prefer different resource bootstrapping behaviors because of different social identities.Furthermore, we found that the core and edge conditions in the decision logic play different roles in the resource bootstrapping behaviors of novice entrepreneurs, with the core decision logic conditions having a greater impact on the resource bootstrapping behaviors. These findings deepen our understanding of the causal complexity among entrepreneur's social identity, decision logic and resource bootstrapping behaviors. It also provides theoretical guidance for effective resource integration for novice entrepreneurs facing resource constraints.

Histidine Protonation Behaviors on Structural Properties and Aggregation Properties of Aβ(1-42) Mature Fibril: Approaching by Edge Effects.

The histidine behavior plays a crucial role in the structural and aggregation properties of protein folding and misfolding. Understanding the histidine behavior at the edge of the protein structure is critical for finding ways to disrupt fibril elongation and growth, but this impact remains poorly understood. In the current study, we used molecular dynamics simulations to investigate the edge substitution effect of histidine protonation on the structural and aggregation properties. Our data showed that ΔG1 contributed the most to binding affinity compared to ΔG2 and ΔG3. The different protonation states at the edge chain significantly impacted the secondary structure properties of the edge chain. Specifically, we found that such protonation behavior significantly affected specific regions, particularly the N-terminus (G9-Q15) and C-terminus (K28-A30). Further analysis confirmed that H6, H13, and H14 were directly involved in H-bonding networks with the C1_H14//C2_H13 interchain interactions critical for maintaining the interchain stability. Furthermore, we confirmed that H6, H13, and H14 were directly involved in the loss of the carbon skeleton contact in the N-terminus. Our findings indicate that the edge condition is more susceptible to changes in structural properties than the middle condition. The current study is helpful for understanding the histidine behavior hypothesis in related misfolding diseases.

Hydroelastic analysis of a forced circular elastic floating plate in the presence of porous barrier

The hydroelastic behavior of a forced circular elastic floating plate is analyzed, while considering the existence of vertical barrier. This study encompasses different edge conditions such as free, simply supported and built-in edge conditions. The eigenfunction matching method is employed with circular symmetry to obtain the solution in frequency-domain. The analysis in time-domain is performed by considering Gaussian forcing at different points on the plate, utilizing the Fourier transform for analysis. The study examines the vertical force acting on the plate and the time-dependent deflection at the point of force application, taking into account different permeable barriers and fluid depths. Additionally, the numerical findings are assessed and compared to the current ones for validation. The findings indicate that the plate encounters maximum force under a built-in edge condition. Furthermore, the time-dependent deflection of the point of forcing decreases with rising values of both the real and imaginary parts of the porous effect parameter G over the time. The outcomes arising from integrating a circular elastic plate with a porous barrier will provide valuable insights into how the plate responds to abrupt forces, similar to those experienced in seismic events or unforeseen disturbances and it also helps in the design of structures capable of enduring unexpected impacts or shocks, among other considerations.

Dynamical behavior of fluid–structure interaction in ducts with rigid and flexible interfaces: Modeling and analysis

This study investigates the propagation of fluid–structure coupled waves in a duct featuring both rigid and flexible interfaces. Two cases are considered: in the first case, with a rigid interface, the truncated form of solution preserves the conservation law, while in the second setting, the power balance is not preserved initially, but is rectified as the number of modes, denoted as N, approaches infinity. The discrepancy is explained by specific equations and the presence of delta functions to enforce edge conditions on the membrane at the interface. The Galerkin approach is adopted to address this issue, expressing the membrane’s displacement using a generalized Fourier series. The investigation establishes a framework for modeling higher-order boundary conditions within a duct, employing the mode-matching (MM) method. The study also delves into the scattering components of power, which vary significantly for the two cases. These findings have implications for noise control devices, particularly in active noise control measures utilizing flexible components to dampen both noise and structural vibrations.

Nonlinear bending and buckling analysis of 3D-printed meta-sandwich curved beam with auxetic honeycomb core

The present study investigates the static responses of a 3D-printed polymeric meta-sandwich curved beam with an auxetic honeycomb core, including buckling and nonlinear bending behavior. After extracting the mechanical properties of the core material, the nonlinear governing equations for the curved beam under two types of loading, namely uniform transverse and axial mechanical loads, are derived based on the first-order shear deformation theory and von-Kármán nonlinearity. After examining the convergence of the static responses and validating them by using the Ritz method, the influence of various geometrical parameters of the 3D-printed meta-sandwich structure on the results of buckling and nonlinear bending behavior as well as their optimization using the response surface methodology (RSM) are studied. The results indicate that by increasing the thickness-to-length ratio of the inclined wall, the critical load of the auxetic sandwich beam is enhanced due to improved stiffness, and its lateral displacement declines. The amount of buckling load increase from m = 0.005 to m = 0.1 is 1.92% in the clamped-clamped boundary conditions, 1.56% in the clamped-simply supported conditions, and 1.2% in the simply supported-simply supported edge conditions. Therefore, by selecting appropriate geometrical parameters for the core cells, the occurrence of instability can be delayed, leading to enhanced buckling resistance of the structure. Furthermore, optimizing the results by using the RSM showed that the highest critical load value and the lowest transverse deflection value of the meta-sandwich curved beam are obtained when θc = 15, n = 1, m = 0.1, 2θ0= 30, b = 0.07, λ= 1.1, h/h2= 1.2, and the edge conditions are of the clamped-clamped type.

On oblique interaction of water waves with semi-infinite submerged elastic plate

Abstract This article relates with the interaction of water waves obliquely incident on a semi-infinite submerged elastic plate of insignificant thickness. The solution is obtained using method of mode matching. Reflection coefficients under the variation of various physical parameters: submergence depth, angle of incidence, stiffness of elastic plate and Poisson’s ratio, for two different edge conditions (i) pinned edge condition and (ii) sliding edge condition are discussed. Convergence and validation of results is also given. Behaviour of the velocity potentials around semi-infinite submerged elastic plate for different physical parameters are also analyzed. The consequences are explained through numerical and graphical results. More over energy balance relation is also discussed.

The effect of different edge conditions on the motion of a submerged elastic disc

The present study examines the effects of various edge conditions of a submerged flexible disc on wave propagation for infinite-depth water within the framework of linear water waves theory. Three types of edge conditions (namely Free edge, simply supported edge, and clamped edge) are taken into consideration for the analysis. The governing boundary value problem (BVP) has been solved by reducing it to a two-dimensional hypersingular integral equation. The notion of modal analysis has been adopted to examine the structural response of the disc on the propagation of waves. Later, the two-dimensional hypersingular integral has been transformed into a second kind one-dimensional Fredholm integral equation by applying Fourier series expansion. Finally, the Nystrom technique based on Gauss–Legendre quadrature nodes is used to obtain an approximate solution of the one-dimensional integral equation. The computed solution is used to evaluate the numerical estimates of the physical quantities such as added mass, damping coefficient, hydrodynamic force, and surface elevation for different edge conditions mentioned earlier.

A study on attenuation patterns of acoustic waves in waveguide structures with flexural boundaries

This research article investigates the attenuation patterns of acoustic waves within waveguide structures featuring flexural boundaries. By employing advanced methods in vibrations and controls, the study aims to enhance our understanding of waveguide behavior and offer valuable insights for optimizing acoustic wave propagation in diverse applications. The entire waveguide structure is tuned through cooperative interactions involving elastic plates, membranes, and rigid boundary surfaces. The lower boundary of the expansion chamber consists of a rigid plate, with elastic membranes covering the upper surfaces of the cavity. The problem is formulated in terms of transmission and reflection coefficients of the modes, enabling the solution of the scattering problem. Matching acoustic pressure and velocity at the waveguide junction yields the scattering coefficients. The results reveal that the scattering coefficients are intricately influenced by both the geometric characteristics of the waveguide and the frequency of the incident waves. Notably, the first higher-order mode of the cut-off frequency of the waveguide structure corresponds to the frequency at which the dissipation coefficient reaches its maximum value. This research provides valuable insights into the scattering behavior of acoustic waves in waveguide configurations, contributing to the design of acoustic devices and systems. Rigorous support and justification for all aspects of the mode-matching method, including pressure and velocity matching, eigen properties, physical edge conditions, convergence criteria, and energy conservation, are provided through thorough algebraic and numerical analyses, confirming the validity of the solution methodology.

Core performance predictions in projected SPARC first-campaign plasmas with nonlinear CGYRO

This work characterizes the core transport physics of SPARC early-campaign plasmas using the PORTALS-CGYRO framework. Empirical modeling of SPARC plasmas with L-mode confinement indicates an ample window of breakeven (Q &amp;gt; 1) without the need of H-mode operation. Extensive modeling of multi-channel (electron energy, ion energy, and electron particle) flux-matched conditions with the nonlinear CGYRO code for turbulent transport coupled to the macroscopic plasma evolution using PORTALS reveals that the maximum fusion performance to be attained will be highly dependent on the near-edge pressure. Stiff core transport conditions are found, particularly when fusion gain approaches unity, and predicted density peaking is found to be in line with empirical databases of particle source-free H-modes. Impurity optimization is identified as a potential avenue to increase fusion performance while enabling core-edge integration. Extensive validation of the quasilinear TGLF model builds confidence in reduced-model predictions. The implications of projecting L-mode performance to high-performance and burning-plasma devices is discussed, together with the importance of predicting edge conditions.

Dispersion by submerged pinned/sliding finite elastic plate

Submerged structures are quite important in ocean and marine sciences. In this article, we have presented the solution of finite submerged elastic plate of negligible thickness. Solution is obtained using the method of mode matching with two different edge conditions: (i) pinned edge condition and (ii) sliding edge condition. Reflection coefficient at both edges for different values of physical parameters: submergence depth, length and stiffness of elastic plate is analyzed. Surface and plate displacement for both edge conditions is also presented. Since the gradient of velocity potential gives insight about the velocity of particles, therefore, the way it behaves in different regions around elastic plate is also discussed. Furthermore energy balance relation for the finite submerged elastic plate is also given.

Influence of Pile Spacing on the Compressive Bearing Performance of CEP Groups

Pile spacing is an important factor affecting the bearing capacity of concrete expansion pile (CEP) groups. In this study, a pile group was simulated and analyzed using ANSYS software R19.0. The influence of pile spacing on the bearing capacity of the pile group under a vertical load was determined using three sets of four-, six-, and nine-pile models with different pile spacings. The grid division of the pile soil model adopts a mapping method, using the contact types of rigid and flexible bodies and applying surface loads to the model piles step-by-step. After vertical pressure was applied to the model pile, in-depth analysis was conducted on the displacement cloud map, pile top displacement, and other data. The different stress conditions of corner, edge, and center piles in each model group were compared and analyzed, revealing the relationship between the stress mechanism and failure law of the soil around the pile and the pile spacing. It was found that the soil displacement range of edge piles is slightly larger than that of corner piles. This phenomenon gradually decreases with increasing pile spacing. When the pile spacing increases to four times the cantilever diameter, the difference in soil displacement at different pile positions is small, and the pile spacing has little effect on the compressive bearing capacity of the pile group. Thus, it is reasonable to control the pile spacing at three to four times the cantilever diameter. In the nine-pile model, when the load is loaded to the 20-step level, the displacement value of the central pile is −72.278 mm, while the displacement values of the edge pile and corner pile are −69.012 mm and −66.806 mm. It is shown that increasing the pile spacing can effectively reduce the pile group effect and improve the bearing capacity of the pile foundation. At present, CEP pile groups are gradually being applied in practical engineering, but research on the influence of pile spacing on the compressive bearing performance of CEP pile groups is still at a very early stage. This article reinforces the influence of pile spacing on the compressive bearing performance of CEP pile groups. It provides theoretical support for its application in practical engineering.

Study on ultimate capacity and design method of cold-formed steel equal lipped angle components under axial compression

This study focuses on evaluating the load-bearing capacity of cold-formed steel (CFS) equal lipped angle components. It delves into the structural behavior and design methods, taking into account various edge conditions and buckling modes. By considering the key parameters, which are component length, component thickness, total lip length, and lip bending angle, a total of 555 numerical models are developed for a systematic analysis on the components with two types of cross-sectional shapes. Since the coefficients within the direct strength method (DSM) inadequately capture the ultimate load-bearing capacity of lipped angle components, we introduce a design methodology rooted in the DSM framework to address global and global-local coupling buckling modes while imposing constraints to prevent local-distortion coupling buckling modes. The machine learning models (XGBoost, BPNN, and 1D-CNN) are adopted to predict the structural behavior of the two types of lipped angle components. These models can integrate the analysis of the components with two types of cross-section shapes in predictions of ultimate load capacity, axial deformation, and buckling modes. Meanwhile, the prediction accuracy of the machine learning models surpasses that of the analytical design methodology, offering more accurate prediction for ultimate load capacity, axial deformation and buckling modes.