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Colloidal probes are often used in force microscopy when the geometry of the tip–sample interaction should be well controlled. Their calibration requires an understanding of their mechanical response, which is very sensitive to the details of the force sensor consisting of a cantilever and the attached colloid. We present some analytical models to describe the dynamics of the cantilever and its load positioned anywhere along its length. The thermal noise calibration of such probes is then studied from a practical point of view, leading to correction coefficients that can be applied in standard force microscope calibration routines. Experimental measurements of resonance frequencies and thermal noise profiles of raw and loaded cantilevers demonstrate the validity of the approach. [ABSTRACT FROM AUTHOR]

H−T phase diagrams for chromium oxide chloride (CrOCl) are usually obtained using data from the measurements of magnetization and specific heats. Recent works suggest that magnetic anisotropy exists in CrOCl. In this work, we use dynamic cantilever magnetometry, which is sensitive to both magnetization and magnetic anisotropy, to probe phase transitions in CrOCl flakes. Together with magnetization measurements from a Superconducting Quantum Interference Device, four major regions of the CrOCl H−T phase diagram along its c-axis are obtained, which is consistent with the previously reported works. Then, we studied magnetic field induced transitions in CrOCl flakes under four different temperatures. Several transitions in antiferromagnetic state and in incommensurate state, which have not been reported before, were recognized. We believe these transitions probably originate from magnetic anisotropy due to magnetoelastic coupling and lattice reconstruction in CrOCl. Our work provides intriguing experimental results on the intricate magnetic structure of CrOCl, making progress in understanding the rich magnetic states of CrOCl. [ABSTRACT FROM AUTHOR]

Photothermal excitation at frequencies below the mechanical resonance of the atomic force microscopy (AFM) microcantilever can be utilized in force modulation microscopy, fast force displacement curve acquisition, and tip-based mass spectroscopy. To understand the microcantilever bending response in these modes, accurate models of the thermoelastic response of the AFM microcantilever are needed. We study the sub-resonance photothermal vibrational response of coated and uncoated AFM microcantilevers as a function of laser modulation frequency and spot location. The sub-resonance microcantilever response shows distinct thermoelastic regimes. Below the microcantilever's thermal roll-off frequency, the vibration amplitude is mostly constant. Past this frequency, the vibration amplitude decreases with increasing frequency. At modulation frequencies below the thermal roll-off frequency, the most efficient photothermal laser spot to excite harmonic motion is near the free end of both coated and uncoated microcantilevers. For the tested coated microcantilevers, the most efficient photothermal laser location migrates from near the free end of the microcantilever to near the fixed end as modulation frequency increases. For the tested uncoated microcantilever, the most efficient photothermal laser location remains unchanged at the tested frequencies. To predict the bending response of the coated microcantilever, a bilayer bending model is implemented. At low frequencies, this model underpredicts the bending response compared to experiments by up to 90%. This may be due to neglecting microcantilever bending contributed by a through-thickness temperature gradient. Our results illustrate different aspects of the frequency-dependent photothermal laser spot optimization that can guide users to maximizing microcantilever response to a given input power. [ABSTRACT FROM AUTHOR]

Lateral-torsional buckling (LTB) is the primary failure mode for thin-walled steel members where the cantilever beams experience nonuniform twisting and buckling about their weak axes. Much research exists in the literature, and modern codes have presented simple formulations for calculating of elastic LTB load of simply-supported beams. However, there are limited numbers of treatments for predicting of elastic LTB load of cantilevers, most of which are numerical, because as different from the simply supported beams, the LTB failure mode of the thin-walled cantilevers is much more complicated. The present study aims to develop a simplified equation for calculating the elastic LTB of the cantilevers with the European standard I-section. First, an analytical model considering first-order bending distribution, load height level, and monosymmetry property of the section has been introduced. Then, a simplified formula for cantilevers has been introduced utilizing the analytical model and two dimensionless coefficients called the slenderness and the load case parameters. The presented analytical solutions were verified with the finite element analysis (FEA), and the effects of slenderness and loading positions on the LTB behavior of cantilevers with European standard I-section have been investigated. It is found analytical solutions are quite compatible with FEA, and the proposed equation could be safely used for calculating the elastic LTB of the cantilevers. [ABSTRACT FROM AUTHOR]

"The Abuse of Conscience: A Century of Catholic Moral Theology" by Matthew Levering is a sourcebook that explores the thoughts of twentieth-century thinkers on the topic of conscience in Catholic moral theology. Levering responds to three starting points: the Pinckaers-Dominican tradition, the failure of thinkers outside of that tradition to revitalize moral theology, and Brian Besong's challenge to denigrate moral manuals. The book consists of four chapters that cover various perspectives on conscience, including its relationship to the Bible, moral manuals, Thomism, and German thought. Levering concludes by presenting two contrasting visions of morality: one emphasizing conscience and the other emphasizing an integrative theology of morals and Christological-Trinitarian mystery. [Extracted from the article]

Natural vibration characteristics of a cantilever beam that is parametrically excited by pitch motion are theoretically investigated in this work. A partial differential equation governing the parametrically excited bending vibration of the beam is established by employing the generalized Hamiltonian principle. Normal modal functions of the bending vibration are obtained based on the method of separation of variables. It reveals that the dynamic pitch motion cannot change the modal shapes of the bending vibration of a uniform beam. Principal vibrations of the beam are studied by taking into account two cases of E I 1 = E I 2 and E I 1 ≠ E I 2 , where E I 1 and E I 2 are the first and second principal bending stiffness, respectively. The bending stiffness is considered as the superposition of a constant stiffness with a small perturbation. With the aid of the Fourier series theory and the method of multiple scales, the principal vibrations of the parametrically excited system at non-resonant and resonant cases are analyzed by introducing a small natural parameter , while natural vibration characteristics of the beam are obtained and the orthogonal properties of modal functions are illustrated. Theoretical methods provided in this work are verified by using the finite element method, assumed modes method and direct numerical integrations to the governing equation based on a rectangular beam model. It reveals that theoretical results coincide with numerical results very well. Finally, the influences of design parameters including the beam height, beam width, beam length, slender ratio, aspect ratio, pitch amplitude, pitch frequency and pitch phase on natural frequencies of a harmonic pitching beam are discussed. It shows that the width, height, length, slender ratio, aspect ratio and pitch amplitude have dramatic influences on the natural frequencies of the pitching beam, while the pitch frequency and pitch phase have little effect on natural frequencies. [ABSTRACT FROM AUTHOR]

The cantilevered micro-beam is an important component in the field of Atomic Force Microscope (AFM) and its behavior is governed by chaotic dynamics. To better understand these dynamics, a theoretical model based on the Euler–Bernoulli beam model has been developed and experiments have been conducted. The model incorporates both the modified couple stress theory (MCST) and external forces to account for the size-dependent effect and electrostatic load. The reduced model in one degree of freedom is obtained by the Galerkin method. The validity of the reduced model is tested by comparing the results from simulations and published results and experiments. The Melnikov method is then used to detect the chaotic threshold the cantilevered micro-beam. The numerical results test the effects of MCST on the complex responses of the micro-cantilever. Implications of the research can extend to the design and optimization of MEMS devices. [ABSTRACT FROM AUTHOR]

Measuring viscosity in volumes smaller than a microliter is a challenging endeavor. A new type of microscopic viscometers is presented to assess the viscosity of Newtonian liquids. Micron-sized flexible polymer cantilevers are created by two-photon polymerization direct laser writing. Because of the low stiffness and high elasticity of the polymer material the microcantilevers exhibit pronounced Brownian motion when submerged in a liquid medium. By imaging the cantilever's spherically shaped end, these fluctuations can be tracked with high accuracy. The hydrodynamic resistance of the microviscometer is determined by fitting the power spectral density of the measured fluctuations with a theoretical frequency dependence. Validation measurements in water-glycerol mixtures with known viscosities reveal excellent linearity of the hydrodynamic resistance to viscosity, allowing for a simple linear calibration. The stand-alone viscometer structures have a characteristic size of a few tens of microns and only require a very basic external instrumentation in the form of microscopic imaging at moderate framerates (~ 100 fps). Thus, our results point to a practical and simple to use ultra-low volume viscometer that can be integrated into lab-on-a-chip devices. [ABSTRACT FROM AUTHOR]

Electromechanical transduction gain of 21 dB is realized in a micro-cantilever resonant force sensor operated in the unresolved-sideband regime. Strain-dependent kinetic inductance weakly couples cantilever motion to a superconducting nonlinear resonant circuit. A single pump generates motional sidebands and parametrically amplifies them via four-wave mixing. We study the gain and added noise, and we analyze potential benefits of this integrated amplification process in the context force sensitivity. [ABSTRACT FROM AUTHOR]

Piezoelectric hydraulic pumps play a pivotal role in more electric aircraft and all-electric aircraft utilizing power-by-wire technology, owing to their high power density and reliability. The cantilever reed valve (CRV) serves as a crucial component within these pumps, and its dynamic behavior within the fluid directly impacts the pumps' output power. A precise mathematical model of the CRV is essential for understanding its motion mechanisms. However, existing models for the CRV inadequately capture its dynamics and fail to explain the observed motion phenomena. Further exploration into dynamic modeling of the CRV is warranted. This paper employs finite element analysis to investigate CRV's dynamics, revealing the significant impact of squeeze flow on CRV's dynamics and identifying the cause of slow closure. Based on this, a novel lumped parameter model incorporating squeeze force is proposed to accurately depict CRV's dynamics, particularly focusing on the phenomenon of slow closure. To validate the proposed model's accuracy, an experimental system capable of independently driving the CRV is constructed to eliminate interference resulting from integrating the CRV into the pumps. The results show that the dynamic response during closure, as predicted by the proposed model, is in good agreement with the outcomes from finite element analysis. Notably, the proposed model exhibits an 11.11% higher prediction accuracy for experimental closing times compared to the traditional model that neglects squeeze forces. This study offers guidance for optimizing CRV's dynamics and improving the performance of piezoelectric hydraulic pumps in future applications. [ABSTRACT FROM AUTHOR]

The aviation ecosystem is increasingly coming under pressure to decarbonise from the public and governments. Airports are at the leading edge of transforming their operations, alongside airlines and aerospace companies. While, however, the levers to reduce Scope 1 and 2 airport emissions are well understood, how to address Scope 3 emissions (which account for the bulk of an airport's emissions) remains a major challenge. This paper provides an overview of potential Scope 3 decarbonisation levers across aircraft operations, ground transport and infrastructure construction. The paper then assesses the potential impact on emissions, and ease of implementation of these levers, highlighting aircraft operations as the area with highest potential to reduce ecosystem emissions. Next, the paper looks at how some of these levers have been implemented in practice, based on the case study of Geneva Airport, focusing on supporting sustainable mobility, energy support for aircraft and financial incentives for airlines to use latest-generation aircraft. The paper then identifies and discusses key barriers that must be overcome, including the ability of airports to influence domains outside their direct control, competing governmental policies and need for investment, highlighting the need for collaboration between a wide range of stakeholders. Based on this, the paper suggests a number of actions that airports should take to satisfy stakeholders and catalyse the aviation ecosystem towards its goal of achieving net zero. [ABSTRACT FROM AUTHOR]

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

Meshless methods are a type of numerical method used to simulate continuum mechanics problems. These methods have been applied to several types of problems, there are a few works using meshless method focused on dynamic problems, but most works study static loading conditions. The current work aims at using two different meshless methods, the Radial Point Interpolation Method (RPIM) and the Natural Neighbours RPIM (NNRPIM), in a dynamic problem, specifically forced vibrations. This problem requires time integration, therefore three different time integration methods have also been tested, namely: the Central Difference Method (CDM), the Wilson method, and the Newmark method. The CDM is an explicit method, while the other two are implicit. A discretization study was performed to assess the ideal nodal discretization before the numerical and time integration methods are validated. For the implicit methods, different time step lengths were also tested. In the final example damping was introduced. The results prove the validity of the two meshless methods by having similar results to the Finite Element Method (FEM) using the three distinct time integration methods, different loading conditions, and damping. [ABSTRACT FROM AUTHOR]

We numerically and experimentally developed a cantilever that provided both fast and analog actuation for THz metamaterials (MMs) by properly geometrizing a dimpled tip. Owing to its small size and light mass, the cantilever had a high mechanical resonance at 705 kHz. Cantilever arrays were fabricated with different tip gaps and integrated into a ladder-shaped MM (LS-MM). By changing the tip gap from 0.80 to 0.32 μm, the resonance of the transmittance spectrum changed from 1.235 to 0.795 THz, indicating that the reconfigurable LS-MM was capable of continuously tuning the resonance of the THz wave transmission with the tip gap. Additionally, the dimple served as an anti-stiction structure, providing the cantilever with a fabrication yield of 99.8%. This work shows a practical pathway to high-performance active metamaterials, which holds potential in advanced THz technologies such as 6G communications and fast imaging. [ABSTRACT FROM AUTHOR]

This study investigated the force–frequency characteristics of quartz wafers inside a cantilever beam frame. Firstly, the force–frequency coefficient formula of quartz wafers with fixed ends under axial force was analyzed. Firstly, the formula for the force–frequency coefficient of quartz wafers with fixed ends under axial force was analyzed. A force–frequency coefficient formula suitable for cantilever beam structures was derived by considering the changes in surface stress and stiffness of quartz wafers with fixed ends and one end under force on the other. Subsequently, the formula's accuracy was verified by experiments, and the accuracy was more than 92%. In addition, strain simulation analysis was performed on three different shapes of quartz wafers, and experimental verification was carried out on two of them. The results revealed that trapezoidal quartz wafers and cantilever beam structures exhibited superior stress distribution to rectangular chips. Furthermore, by positioning electrodes at various locations on the surface of the quartz chip, it was observed that, as the electrodes moved closer to the fixed end, the force–frequency coefficient of the rectangular quartz chip increased, along with an increase in chip strain under the cantilever structure. In summary, this study provides a new approach for designing cantilever quartz resonator sensors in the future. [ABSTRACT FROM AUTHOR]

New chiral targets of orientational chirality have been designed and asymmetrically synthesized by taking advantage of N‐sulfinyl imine‐directed nucleophilic addition/oxidation, Suzuki‐Miyaura, and Sonogashira cross‐coupling reactions. Orientation of single isomers has been selectively controlled by using aryl/alkynyl levers [C(sp2)‐C(sp) axis] and tBuSO2‐ protecting group on nitrogen as proven by X‐ray diffraction analysis. The key structural characteristic of resulting orientational products is shown by remote through‐space blocking manner. Seventeen examples of multi‐step synthesis were obtained with modest to good chemical yields and complete orientational selectivity. [ABSTRACT FROM AUTHOR]

Atomic force microscopy (AFM) is a technique that relies on detecting forces at the nanonewton scale. It involves using a cantilever with a tiny tip at one end. This tip interacts with the short- and long-range forces of material surfaces. These cantilevers are typically manufactured with Si or Si3N4 and synthesized using a lithography technique, which implies a high cost. On the other hand, through simple chemical methods, it is possible to synthesize a magneto-dielectric composite made up of artificial SiO2 opals infiltrated with superparamagnetic nanoparticles of Fe3O4. From these materials, it is possible to obtain tipless cantilevers that can be used in AFM analysis. Tipless cantilevers are an alternative tool in nanoscale exploration, offering a versatile approach to surface analysis. Unlike traditional AFM probes, tipless versions eliminate the challenges associated with tip wear, ensuring prolonged stability during measurements. This makes tipless AFM particularly valuable for imaging delicate or soft samples, as it prevents sample damage and provides precise measurements of topography and mechanical and electromechanical properties. This study presents the results of the characterization of known surfaces using magneto-dielectric cantilevers and commercial cantilevers based on Si. The characterization will be carried out through contact and non-contact topography measurements. [ABSTRACT FROM AUTHOR]

In this paper, an energy harvester consisting of a cantilever beam, magnets, and magnetic springs embedded on its structure is proposed to harvest electricity energy. In order to extract energy from the system permanently, an adaptive controller is proposed. With the help of the proposed controller, it is prevented from damping the oscillations of the beam or excessive increasing in the amplitude of these oscillations. Also, the use of the proposed controller provides the possibility that despite the presence of unknown external disturbances such as wind waves and sudden changes of sea waves, as well as the uncertainty of the parameters of the cantilever beam, a permanent energy is harvested from the proposed mechanism. The equations describing the electromechanical behavior of the proposed mechanism are derived from Lagrange equations. On the other hand, dynamic surface control technique is employed to design the adaptive and control laws. The stability of the closed-loop system is shown using Lyapunov stability theory, and the tracking error converges to a small neighborhood around the origin. Numerical simulation for cantilever beam is investigated to clarify the effectiveness of the proposed mechanism and controller. [ABSTRACT FROM AUTHOR]

In this study, the bending-bending coupled static behavior of functionally graded and porous pretwisted cantilever Timoshenko beams is reported. Symmetric power-law distribution is employed as the material profile and it is assumed that porosity can disperse over the cross-section in two forms namely, even and uneven distributions. Two different yet equivalent forms of governing equations are obtained by formulating the problem in the fixed and curvilinear coordinate systems, respectively. The initial values method is adopted as the solution methodology. While the fundamental matrix is computed numerically by using the multiplicative integral of Volterra to obtain the solution in the fixed coordinate formulation, the matrix exponential which allows for obtaining exact expressions is utilized in the curvilinear coordinate formulation. Exact analytical deflection expressions are presented for space-fixed vertical tip force and body-fixed uniform distributed force cases. It is shown that both formulation approaches yield consistent results with each other and those obtained from the finite element analyses. In addition, several parametric studies that investigate the effects of the volume fraction index, porosity coefficient, and porosity distribution on the tip deflections are presented. [ABSTRACT FROM AUTHOR]

This paper describes an improved process for controlling the initial deflection structure of cantilever‐type MEMS tactile sensors. By using residual stress, deposition sequence, and metal layer patterns, the initial deflection of the cantilever was successfully aligned to the same initial deflection with micron accuracy and 97% yield in a simpler and easier process than previous processes. This enables a reduction in the number of processes and flexible control of deflection, which is expected to improve yield and shorten fabrication time. © 2024 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Research summary: The primary outcome desired for juvenile delinquency programs is the cessation of delinquent and related problematic behaviors. However, this outcome is almost always pursued by attempting to change intermediate outcomes, such as family functioning, improved mental health, or peer relations. We can conceptualize intermediate outcomes that are related to reduced delinquency as change levers for effective intervention. A large meta‐analysis identified several school‐related change levers, including school engagement (i.e., improved attendance and reduced truancy), nondelinquent problem behaviors, and attitudes about school and teachers. In addition, family functioning and reducing substance use were also effective change levers. In contrast, effects on youth getting/keeping a job, peer relationships, and academic achievement were not associated with reduced delinquency. Policy implications: Only a small percentage of rehabilitative programs provided to youth involved in the juvenile justice system have been established as evidence based. Moreover, there are constraints on what local policy makers and practitioners can do regarding the selection, adoption, and implementation of programs from the available lists of evidence‐based programs. Adopting programs that focus on effective change levers and avoiding those that concentrate on ineffective ones has the potential to increase the likelihood that a local agency is engaged in effective programming. Based on our data, programs known to improve family functioning, attachment to and involvement in schooling, and reducing substance use are justified by the change lever evidence, even if these programs' effectiveness in reducing delinquency has not been directly proven. In contrast, programs focusing on vocational skills, academic achievement, and peer relations are less likely to be beneficial. Furthermore, a change lever perspective can help frontline staff select appropriate programs for different juvenile offenders and focus their quality control efforts on those aspects of a program that are likely to be essential to maintaining effectiveness. [ABSTRACT FROM AUTHOR]

The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches. An improved experimental specimen is designed in order to satisfy the cantilever support boundary condition, which is composed of an asymmetric region and a symmetric region. The symmetric region of the experimental specimen is entirely clamped, which is rigidly connected to an electromagnetic shaker, while the asymmetric region remains free of constraint. Different motion paths are realized for the bistable cantilever shell by changing the input signal levels of the electromagnetic shaker, and the displacement responses of the shell are collected by the laser displacement sensors. The numerical simulation is conducted based on the established theoretical model of the bistable composite laminated cantilever shell, and an off-axis three-dimensional dynamic snap-through domain is obtained. The numerical solutions are in good agreement with the experimental results. The nonlinear stiffness characteristics, dynamic snap-through domain, and chaos and bifurcation behaviors of the shell are quantitatively analyzed. Due to the asymmetry of the boundary condition and the shell, the upper stable-state of the shell exhibits an obvious soft spring stiffness characteristic, and the lower stable-state shows a linear stiffness characteristic of the shell. [ABSTRACT FROM AUTHOR]

An efficient treatment plan using a temporary anchorage device should be built following the principle of reducing the number of tads to obtain a multiple biomechanical advantage. The following case report concerns the Biga system, a strategy that supports orthodontists during class II corrections and vertical control through treatment. A 12-year-old girl with a high angle of skeletal class II was selected. A novel biomechanical strategy was effectively applied using two tads on the upper arch to obtain sequential distalization of the upper teeth and to correct the lower arch spee curve using third-class elastics. Eventually, on the same tads, a double cantilever was applied to control the overbite and intrusion during incisors' retraction. The Biga system is an easy biomechanical strategy that ensures the three-dimensional control of treatment mechanics in class II patients. [ABSTRACT FROM AUTHOR]

We propose a novel high‐performance dual‐resonance enhanced photoacoustic spectroscopy (DRE‐PAS) gas sensor based on a highly sensitive fiber optic cantilever beam microphone and a high‐Q spherical photoacoustic cell (PAC). The first‐order resonant frequency (FORF) of the spherical PAC is analyzed by finite element analysis to match the FORF of the cantilever microphone for the double resonance enhancement of the photoacoustic signal. The photoacoustic spectroscopy (PAS) system, including the DRE‐PAS sensor, a 1532.8 nm distributed feedback laser, and a high‐speed spectrometer, has been successfully exploited for trace acetylene (C2H2) detection. The experimental results show that the limit of detection (LOD) is 106.8 parts‐per‐billion (ppb) with an integral time of 1 s, and the LOD can be further reduced to 11.03 ppb by Allan‐Werle deviation for 100 s integral time. The normalized noise equivalent absorption coefficient can be obtained as 2.44 × 10−8 cm−1 WHz−1/2. The reported DRE‐PAS gas sensor has the superior characteristics of photoacoustic signal enhancement, high sensitivity, and strong antielectromagnetic interference capability, which can provide a new solution for PAS development. [ABSTRACT FROM AUTHOR]

A novel two‐parameter sensor is proposed based on the abrupt taper and micro‐arc Michelson interferometer (MI) in single‐mode fiber. When there is a regular change in the liquid level or temperature, the phase difference changes, and the spectral intensity or wavelength of the interfering valleys of this sensor is directionally shifted. This study enriches the construction of MI and provides a new perspective on liquid level measurement. We experimentally explored the sensor's sensing performance over temperature and liquid level: this sensor's temperature sensitivity and liquid level sensitivity were up to 62.9 pm/°C and 0.2896 dB/mm, respectively. In addition, this sensor is characterized by compactness, simplicity, low cost, and high reliability, and it is suitable for measurement of liquid level and temperature, expanding the application field of MI. [ABSTRACT FROM AUTHOR]

This work proposes a monostable symmetric piezoelectric energy harvester based on the cantilever structure and magnetic excitation action (M-PEH). The governing equations of M-PEH are derived based on its kinematic properties. The intrinsic frequency of the piezoelectric cantilever beam was obtained by modal simulation. It has been demonstrated that the mode of arrangement of the magnetic poles has a significant effect on the output voltage of the energy harvester. The proposed M-PEH has four driving magnets with a mass of 6 g and a radial driving distance of 15 mm for more efficient energy harvesting. The experimental results show that the maximum voltage of the M-PEH with the double U-type rotor was 31.2 V at 240 rpm and 110 kΩ external resistance. The average power of the PEH with the double U-type rotor was 16.562 mW at a speed of 240 rpm with an outer resistance of 20 kΩ. The energy harvester with a double U-type rotor can realize a voltage output of not less than 10 V in the range of 60–300 rpm when the same poles of the tip magnets are arranged outward. The M-PEH can also easily light up LEDs or miniature electronic watches with speeds of 120 rpm and 240 rpm. This further proves that the proposed piezoelectric energy harvester (M-PEH) has a better energy harvesting effect and great potential for practical applications. [ABSTRACT FROM AUTHOR]

The effects of different shorter to longer section length ratio on the performance of dual section transistor laser is analyzed numerically by solving the coupled rate equations. Dual section transistor laser is configured in common emitter configuration and biased in the active region. The DC and gain levering characteristics of bisection transistor laser is analyzed for different shorter to longer section length ratio ranging from 3:97 to 30:70. The shorter and longer section threshold current are found increase with increase in the shorter to longer section length ratio. A minimum shorter section threshold current of 3 µA is estimated for longer section bias current of 1.6 mA with shorter to longer section length ratio of 3:97. Higher slope efficiency is observed between an optical power and bias current of bisection transistor laser. A maximum gain lever of 9.87 dB is predicted for the shorter to longer section length ratio of 3:97 and gain levering decreases for increase in the ratio. [ABSTRACT FROM AUTHOR]

To measure the interfacial fracture toughness of ceramic/metal interfaces such as thermal spray coatings, a novel modified cantilever beam bending method is proposed. Finite element simulations are used to determine the energy release rate and phase angle for an interfacial crack in a bi-layered cantilever for varying modulus, thickness and beam aspect ratios. A high-throughput experimental procedure for the new test geometry is presented to extract a large number of measurements of interface fracture energy from the same sample, using digital image correlation. Interfacial fracture energies G C , determined using this method are compared for thermal spray coatings of Alumina and YSZ on steel substrates. G C of these coating-substrate combinations follow the same trend as measured from four-point bending or modified clamped beam bend techniques. Advantages and limitations of the technique in comparison to other methods in practice are discussed. [ABSTRACT FROM AUTHOR]

A new technique is assessed in order to measure, at the wafer scale, direct bonding energies. It is derived from the standard Double Cantilever Beam (DCB) method and uses interferometry in confocal IR laser source microscopy to measure crack openings. Such a bonding energy measurement protocol has better accuracy compared to other techniques. This is due to a better confocal microscopy resolution and the high intensity of the laser source. The elastic energy stored in bent wafers is obtained by measuring the beam curvature. DCB deformation models are discussed from the short-range crack opening theory to long distance beam-bending theories. Comparison is made between models, experimental results, and FEM simulations. Finally, the bonding energy error during standard measurements is estimated. [ABSTRACT FROM AUTHOR]

The double cantilever beam (DCB) specimen is widely used to characterise the mode I fracture of adhesive joints. This paper analyses some particular characteristics of adhesively bonded composite DCB specimens which could affect test results. Three-dimensional (3D) and two-dimensional (2D) finite element analyses (FEA) were conducted in order to evaluate the effects bondline constraint and adherend through-thickness flexibility on the specimen response. Since beam theory-based data reduction schemes are widespread, beam models were also employed to analyze the effects of adherend through-thickness flexibility and fracture process zone relative size. It is shown that, although composite adherends are usually thinner and have much lower transverse moduli than metal adherends, the level of bondline constraint is similarly high. This may: limit the level of adhesive plastic deformations in the fracture process zone; generate high bondline tractions that increase the likelihood of interface failure and interlaminar damage in the composite adherends. The present analyses also show relevant effects of adherend through-thickness flexibility in the adhesive elastic loading stage. Finally, smaller fracture process zones relative to metal adherend DCB specimens were predicted by a beam cohesive zone model. This may explain lower fracture energy values reported with composite adherends in some studies. [ABSTRACT FROM AUTHOR]

Vibration of aircraft wings and the dynamic stress concentration at the clamped edge are important research topics due to concerns on the safety of aircrafts. To have a better understanding of the problem, the free and forced vibration response of a ribbed rectangular cantilever plate representing a section of an aircraft wing is investigated in this study. A new analytical solution is developed for the vibration analysis of rib stiffened cantilever plates using Mindlin plate and Timoshenko beam theories alongside the finite integral transform technique. The one- and two-dimensional integral transforms are applied to the governing equations of beams and plates, respectively, where the coupling force components at the interface between the base plate and the beam(s) can be automatically defined during the integral transform. Eventually, the partial differential equations are transformed into a system of linear algebraic equations in which its derivation is rigorous and easily implemented. Good agreements are found between the results of analytical solution, finite element analysis (FEA) and related literature. The solution is then employed to study the vibration suppression of cantilever plates and the shear force at the clamped edge. It is found that the insertion of a pair of orthogonal ribs in the plate can effectively reduce its vibration. An optimum orthogonal ribbing pattern is obtained using multi-objective particle swarm optimization (MOPSO) algorithm, taking into consideration both the vibration suppression of the plate and the maximum induced shear force at the corners of the clamped edge. [ABSTRACT FROM AUTHOR]

The Frenet–Serret (FS) framework stands as a pivotal tool in shape sensing for various infrastructures. However, this tool suffers from accumulative errors, particularly at inflection points where the normal vector undergoes sign changes. To minimize the error, the traditional FS framework is modified by incorporating the homogeneous matrix transformation (HMT) method for segments containing inflection points. Additionally, inclination information is also used to calculate the unit tangent vector and the unit norm vector at the start point of each segment. This novel approach, termed the FS-HMT method, aims to enhance accuracy. To validate the effectiveness of the proposed method, a simulation of a cantilever column was conducted using finite element software ANSYS 19.2. The numerical results demonstrate the capability of the proposed method to accurately predict curves with inflection points, yielding a maximum error of 1.1%. Subsequently, experimental verification was performed using a 1 m long spring steel sheet, showcasing an error of 4.9%, which is notably lower than that of the traditional FS framework. Our proposed modified FS framework exhibits improved accuracy, especially in scenarios involving inflection points. These findings underscore its potential as a valuable tool for enhanced shape sensing in practical applications. [ABSTRACT FROM AUTHOR]

The J-integral is applied to the single cantilever beam (SCB) and double cantilever beam (DCB) test specimens subjected to both mixed-mode I and II loading and large displacements. The methods proposed and resulting closed-form theoretical equations allow for the instantaneous evaluation of J during laboratory tests, requiring only the applied load and angular rotation of the specimen loading link, loading points, and remaining ligament. These measurands can be acquired using a common load cell and markers, a digital video camera, and image analysis software. In general, the equations do require knowledge of the specimen elastic moduli and shear moduli, as well as the specimen linear dimensions. Since the test data can be analyzed and J determined throughout the test instantaneously, and since, due to geometric nonlinearities, the ratio of mode I and mode II loading will likely vary significantly throughout the test, each specimen can be used to generate multiple data points. If crack length is determined throughout the test, presumably by directly measuring the crack length optically, or if the load drops abruptly due to crack growth, then when the crack advances, critical values of J for mixed-mode loading can be determined using the methods and results presented. It is noted that moderate to large translational and rotational displacements may improve the accuracy of the results using these methods. The results are applicable to standard pure mode I or pure mode II SCB and DCB tests as well and reduce to known equations in those special cases. [ABSTRACT FROM AUTHOR]

This paper presents the findings of a large‐scale experimental study that focus on assessing structural behavior of reinforced concrete (RC) cantilever slabs with carbon/epoxy fiber‐reinforced polymer (CFRP) composite strips using a near‐surface‐mounted (NSM) approach. The NSM/CFRP system evaluated in this study was implemented in strengthening the shoulders of the Slide Canyon Bridge in California, USA. The experimental phase is divided into two main parts: (i) determining the design parameters for NSM, including the bondline strength through pull‐out tests, and (ii) conducting a practical evaluation of the bending behavior of original and retrofitted RC cantilever slabs, each with varying NSM reinforcement and three different development lengths. Results of this study indicated that the use of NSM‐CFRP has a considerable benefit in that it significantly improves ductility and changes the failure mode of the unstrengthened RC slab from the typical brittle shear‐based failure mode to a more ductile flexural‐based failure mode. The large‐scale slab specimens' performances, which had different development lengths, showed little variance, except for the slab specimen with a development length of 457.0 mm that exhibited an appreciable flexural stiffness as compared to other specimens evaluated in this study. In order to simulate the serviceability and ultimate behavior of the RC slab specimens, linear and nonlinear finite element analyses were performed. A satisfactory agreement between numerical and experimental results was achieved especially at load level prior the initiation of large‐size cracks. [ABSTRACT FROM AUTHOR]

In this study, cantilever retaining walls constructed near the highways were investigated according to real project values. Twenty-eight retaining wall projects applied in the site at different regions of Turkey such as Central Anatolia, Marmara and Black Sea were considered. The value of surcharge load, depth of foundation, ground water level, surface slope of soil and wall height were chosen as variable parameters, although properties of base soil, granular backfill and natural soil were considered as constant parameters. Theoretical calculations of factor of safeties were completed against overturning, sliding and bearing capacity according to each case as well as twodimensional finite element models were solved in Plaxis software to find the maximum horizontal deformations. Rankine active and passive earth pressure theories were used to make static analysis of cantilever walls. If the surcharge load, surface slope of soil, height of wall and ground water level increases, the stability conditions depending on factor of safeties decreases due to results. In addition, a deeper depth of foundation increases the factor of safeties against sliding and bearing capacity, while it does not affect the overturning behavior. The location of ground water stands out as a dominant parameter rather than other external factors. Therefore, the design height of reinforced concrete cantilever retaining wall is not proposed in which taller than 15m due to unsecure and uneconomical conditions, even if other criteria are met. [ABSTRACT FROM AUTHOR]

The aim of this study is to parametrically analyze the vibration characteristics of weaving needles during the feeding motion, providing effective references for the selection of parameters in the three-dimensional weaving process. To control the degree of carbon fiber wear during the manufacturing process and maximize its maximum forming height, we have established a systematic dynamic model based on Hamilton's principle. The state equation was solved using the Runge-Kutta method. The influence of different weaving parameters on the weaving needle's free-end vibration response and equilibrium position of was studied. The results indicate that the weaving velocity and height of the cross-section have a significant impact on the vibration amplitude of the free end of the weaving needle and the deflection of the equilibrium position. Moreover, the increase in deflection exhibits a certain inhibitory effect on the amplitude. [ABSTRACT FROM AUTHOR]

With the wide application of cantilever roadheader in urban subway tunnel construction, accurate prediction of excavation performance of cantilever roadheader in rock stratum has become a research hotspot. Accurate prediction of tunneling performance of cantilever roadheader in rock stratum is the key to its successful application in tunnel engineering. Based on Guiyang Rail Transit Line 1 and Line 3, this paper conducts field investigation and statistical analysis of data on the construction performance and tunneling characteristics of roadheader, and establishes a prediction database of tunneling performance of hard rock cantilever roadheader. The principal component analysis (PCA) was introduced into the deep belief network (DBN) to optimize the input parameters of the DBN model, and the PCA–DBN model for the performance prediction of hard rock cantilever roadheader was proposed. The new model is trained and predicted based on the data of Guiyang Rail Transit Line 1, and the rationality and feasibility of the model are verified through the field data test and analysis of Guiyang Rail Transit Line 3. The results show that the performance prediction model of hard rock cantilever roadheader based on PCA–DBN can realize real-time and continuous prediction of tunneling performance of ground roadheader in front of tunnel face according to engineering measured data. The comparative analysis with the DBN model shows that the accuracy of the PCA–DBN prediction model is better than that of the DBN model, which can better adapt to complex and changeable geological conditions. The new model provides a new method and possibility for accurately predicting the tunneling performance of cantilever roadheader in hard rock. Highlights: A prediction database of hard rock cantilever roadheader tunneling performance was established. The performance prediction model of hard rock cantilever roadheader based on PCA–DBN was established. The performance prediction model realizes real-time and continuous prediction of tunneling performance of ground roadheader. The prediction accuracy of PCA–DBN is higher than DBN in predicting the performance of cantilever roadheader. [ABSTRACT FROM AUTHOR]

To put frameworks of Responsible Innovation and Responsible Research and Innovation (R(R)I) into practice, engagement methods have been developed to study and enhance technoscientific experts' capacities to reflexively address value considerations in their work. These methods commonly rely on engagement between technoscientific experts and social scholars, which makes them vulnerable to structural barriers to interdisciplinary collaboration. To circumvent these barriers, we adapt Socio-Technical Integration Research (STIR) for broader use within technoscientific communities. We call this adaptation: reflexive practitioner dialogues. While the primary aim of this article is to introduce and explain the methodological adaptation, we also analyze results from a pilot study with participants who are involved in research on contemplative practices such as mindfulness meditation. The analysis is guided by research questions that sought to assess whether and under what conditions the practitioner dialogues support reflexive and practical engagement with value considerations in participants' work. The results indicate that reflexive practitioner dialogues can stimulate reflexive awareness of value conflicts and help re-direct decision-making responsively. We characterize the conditions facilitating such responsiveness as "value exnovators," highlighting the oft-unacknowledged interpersonal relational practices that support collaborative engagement with value considerations. We suggest that "exnovation"—exposing the strengths of given practices for their improvement—can support R(R)I practices by directing analytical attention to their micro-level carriers. [ABSTRACT FROM AUTHOR]

Objectives: To simulate the replacement of a premolar with an implant‐supported cantilever fixed dental prosthesis (ICFDP) and how the fracture load is affected by implant type, positioning within the zirconia blank, and aging protocol. Materials and Methods: Seventy‐two ICFDPs were designed either within the enamel‐ or dentin layer of a 4Y‐PSZ blank for bone‐level and tissue‐level titanium‐zirconium implants. Fracture load was obtained on the cantilever at baseline (no aging) or after aging in a chewing simulator with the load applied within the implant axis (axial aging) or on the cantilever (12 groups with n = 6). A three‐way ANOVA was applied (α =.05). Results: A three‐way ANOVA revealed a significant effect on fracture load values of implant type (p =.006) and aging (p <.001) but not for the position within the zirconia blank (p =.847). Fracture load values significantly increased from baseline bone level (608 ± 118 N) and tissue level (880 ± 293 N) when the implants were aged axially, with higher values for tissue level (1065 ± 182 N) than bone level (797 ± 113 N) (p <.001). However, when the force was applied to the cantilever, fracture load values decreased significantly for tissue‐level (493 ± 70 N), while values for bone‐level implants remained stable (690 ± 135 N). Conclusions: For ICFDPs, the use of bone‐level implants is reasonable as catastrophic failures are likely to be restricted to the restoration, whereas with tissue‐level implants, the transmucosal portion of the implant is susceptible to deformation, making repair more difficult. [ABSTRACT FROM AUTHOR]

The kinetics and durability of conversion‐based anodes greatly depend on the intrinsic stress regulating ability of the electrode materials, which has been significantly neglected. Herein, a stress dissipation strategy driven by multi‐interface built‐in electric fields (BEFs) and architected structure, is innovatively proposed to design ultrafast and long‐term sodium ion storage anodes. Binary Mo/Fe sulfide heterostructured nanorods with multi‐interface BEFs and staggered cantilever configuration are fabricated to prove our concept. Multi‐physics simulations and experimental results confirm that the inner stress in multiple directions can be dissipated by the multi‐interface BEFs at the micro‐scale, and by the staggered cantilever structure at the macro‐scale, respectively. As a result, our designed heterostructured nanorods anode exhibits superb rate capability (332.8 mAh g−1 at 10.0 A g−1) and durable cyclic stability over 900 cycles at 5.0 A g−1, outperforming other metal chalcogenides. This proposed stress dissipation strategy offers a new insight for developing stable structures for conversion‐based anodes. [ABSTRACT FROM AUTHOR]

The kinetics and durability of conversion‐based anodes greatly depend on the intrinsic stress regulating ability of the electrode materials, which has been significantly neglected. Herein, a stress dissipation strategy driven by multi‐interface built‐in electric fields (BEFs) and architected structure, is innovatively proposed to design ultrafast and long‐term sodium ion storage anodes. Binary Mo/Fe sulfide heterostructured nanorods with multi‐interface BEFs and staggered cantilever configuration are fabricated to prove our concept. Multi‐physics simulations and experimental results confirm that the inner stress in multiple directions can be dissipated by the multi‐interface BEFs at the micro‐scale, and by the staggered cantilever structure at the macro‐scale, respectively. As a result, our designed heterostructured nanorods anode exhibits superb rate capability (332.8 mAh g−1 at 10.0 A g−1) and durable cyclic stability over 900 cycles at 5.0 A g−1, outperforming other metal chalcogenides. This proposed stress dissipation strategy offers a new insight for developing stable structures for conversion‐based anodes. [ABSTRACT FROM AUTHOR]

For the cantilever beam vibration model without damping and forced terms, the corresponding differential system is a planar dynamical system with some singular straight lines. In this paper, by using the techniques from dynamical systems and singular traveling wave theory developed by [Li & Chen, 2007] to analyze its corresponding differential system, the bifurcations and the dynamical behaviors of the corresponding phase portraits are identified and analyzed. Under different parameter conditions, exact homoclinic and heteroclinic solutions, periodic solutions, compacton solutions, as well as peakons and periodic peakons, are all found explicitly. [ABSTRACT FROM AUTHOR]

Saleyard Bridge carries the A465 Heads of the Valleys Road over the River Clydach near Gilwern, Monmouthshire, UK. It comprises a 67 m single-span steel–concrete composite multi-girder superstructure made integral with the abutments. A full-depth precast deck was chosen to tackle site constraints and improve constructability. The alternative precast panel connection detail developed used straight laps to overcome the problems that can arise from using typical U-bar loop type connections between precast deck panels. The successful use of the precast panels proved that a deck design with straight laps was a practical alternative. The ability to increase the multi-beam centres and avoid cantilever edge formwork created a more economical solution with savings estimated at £500 000. The paper examines the detailed design and construction planning needed to realise the savings and speed up construction as well as improving site safety. The lessons learnt are also applicable to the wider use of precast panels as an alternative to in situ concreting. [ABSTRACT FROM AUTHOR]

The hydrodynamic force in a thin uniform beam cantilever is essential quantity for designing a resonator. We obtained the hydrodynamic drag forces in a uniform cantilever vibrating at the first four transverse modes using a semi-analytical boundary element method (BEM) and finite element method (FEM) in ANSYS. The present three-dimensional (3D) BEM inertial and damping forces are compared with FEM over a frequency range with less than 9.5% deviation until frequency parameter of 100; thereafter, it deviates numerically due to neglecting the non-linear convective forces. Considering the hydrodynamic damping force, the quality factor is estimated for the first four transverse modes of a uniform cantilever beam. As a result, the present 3D BEM model behaves well at the first bending mode compared to FEM. We also study the effect of the aspect ratio (ratio of width to length) of the beam for all four modes. However, the first mode quality factor sufficiently correlates with the numerical value for all aspect ratios. For uniform beams operating with higher modes, the influence of nonlinear and resonance frequency by the numerical model is more pronounced at smaller lengths. Hence, the 3D BEM approach can estimate the hydrodynamic forces on cantilever-based resonators, for example, atomic force microscopy and biosensors. [ABSTRACT FROM AUTHOR]

The influence of crystal anisotropy on the micromechanical properties of ceramic grains plays an important role in the design of the macromechanical performance of bulk polycrystalline samples. To this end, the effect of crystal orientation on fracture toughness and strength was investigated by microcantilever bending experiments combined with finite element method (FEM) simulations in grains of a polycrystalline ZrB2 sample. The sample was prepared by hot pressing and the crystal orientations were determined by electron backscatter diffraction after careful surface preparation. The bending tests were carried out on notched and unnotched microcantilevers cut from specific grains along the prismatic (⊥ to c‐axis), basal (∥ to c‐axis), and intermediate (45° to c‐axis) directions of ZrB2 crystals using focused ion beam milling. The fracture toughness and strength were determined by FEM‐derived analytical solutions. The fracture strength was similar with values of about 11–12 GPa in every direction. Enhanced plasticity was found in the intermediate direction of unnotched beams as compared to the other two brittle orientations. The fracture toughness was found to be 30% higher in the intermediate direction (4.1 MPa m0.5) than those measured for the basal (3.1 MPa m0.5) and prismatic directions (3.3 MPa m0.5). These findings were explained by the orientation dependence of slip system activations which provide a new way in the design of textured polycrystalline ZrB2 ceramics toward enhanced damage tolerance. [ABSTRACT FROM AUTHOR]

The work reported in this paper describes the design and simulation of a novel current mirror readout circuit based MOSFET integrated cantilever structure for micro-gram (μ g) mass sensing applications. The proposed mass sensing structure consist of silicon cantilever as the micromechanical structure, MOSFET as strain sensing element and current mirror as a readout circuit. In this paper, studies have been carried out on three structures (a) n-channel MOSFET based resistive loaded current mirror integrated cantilever mass sensor (b) p-channel MOSFET based resistive loaded current mirror integrated cantilever mass sensor and (c) n- and p- channel MOSFETs based dual current mirror integrated cantilever mass sensor. The input MOSFET(s) of the current mirror acts as the reference transistor(s) while the output MOSFET(s) of the mirror circuit acts as strain sensing element(s) to measure the cantilever deflection under externally applied load. The structural and the electrical characteristics of the sensors were simulated using COMSOL Multiphysics and TSPICE software respectively. Simulation results showed a sensitivity of 21.89 μ V/ μ g, 1 μ V/ μ g and 115.57 μ V/ μ g for nMOS, pMOS and dual channel cantilever mass sensor. The fabrication steps and mask layout of the proposed sensor have also been presented in this paper. The novelty of this work is emphasized by the innovative integration of a CMOS current mirror circuit with a cantilever for mass sensing. [ABSTRACT FROM AUTHOR]

To obtain high-resolution magnetic force microscopy (MFM) images, it is essential to have a cantilever with a high-quality factor. However, conventional vibrating cantilevers typically have quality factor values in the range of a few hundred, which limits their sensitivity for MFM measurements. To address this limitation, numerous studies have explored methods to enhance the quality factor in different environments, including vacuum, air, and liquid. This study introduces a novel approach for improving the quality factor using flowing helium gas. By selecting helium gas with a low viscosity coefficient, we successfully achieved a higher quality factor (Q-factor) of MFM microcantilever oscillations at room temperature in one atmosphere compared with the Q-factor in air. This provides a potential approach for achieving high-resolution MFM measurements under room temperature conditions. By optimizing the gas flow rate at room temperature in one atmosphere, we successfully obtained a higher MFM cantilever oscillation Q-factor and clearer MFM images compared with the air. The experimental results revealed a long and narrow resonant curve, and the quality factor significantly increased to 778.2, which is 3.8 times higher than that observed in air 205.4. Furthermore, systematic investigations demonstrated the capability of this approach to produce high-resolution MFM images of videotape track patterns under the optimized helium gas flow rate of 60 mm/s. [ABSTRACT FROM AUTHOR]