Elastic Form Research Articles

Accurate and efficient analytical simulation of free vibration for embedded nonlocal CNTRC beams with general boundary conditions

This study aims to evaluate the free vibrational response of embedded restrained nanobeams enriched by nanocomposites based on an exact Fourier series approach. In order to capture the small-scale effects on the dynamical response, Eringen's differential form of nonlocal elasticity is used which employs a scale (nonlocal) parameter. Within the framework of Rayleigh and Bernoulli-Euler beam theories, including the effect of nonlocality and employing the Fourier sine series together with Stokes' transformation, systems of linear equations are obtained and solved using the coefficient matrices. The combined effects of elastic boundary conditions, elastic foundation, dispersion patterns and volume fractions of carbon nanotubes, and nonlocal parameter are examined by solving eigenvalue problems constructed with Fourier infinite series. Free vibration frequencies are calculated for carbon nanotube-reinforced nanobeams under different rigid or restrained boundary conditions, including Winkler-Pasternak type elastic foundation. A comprehensive parametric study is performed, focusing on various effects for the free vibrational response of the composite nanobeam reinforced with carbon nanotubes. It is concluded that adding a small amount of carbon nanotube material can reinforce the stiffness of the composite nanobeam, and its free vibration performance is significantly affected by the distribution patterns, elastic medium, and boundary conditions.

Charge distributions of pseudoscalar and vector mesons from Dyson-Schwinger equations

We combine the Dyson-Schwinger/Bethe-Salpeter equations framework with modern numerical reconstruction methods to derive the three-dimensional and transverse two-dimensional charge distribution of an array of ground-state pseudoscalar and vector mesons from their elastic electromagnetic form factor in the low-momentum region. The charge radii obtained by averaging over the reconstructed charge distributions have been checked to be consistent with those calculated from the slope of the elastic electromagnetic form factor at zero transferred momentum. The capability of the reconstruction procedure for capturing a reliable low-distance charge distribution is discussed and argued to work down to distances of around 0.1 fm, such that it might be potentially applied to extract, e.g., mass densities from gravitational form factors. Published by the American Physical Society 2024

Nuclear medium meson structures from the Schwinger proper-time Nambu–Jona-Lasinio model

In this paper, we report the results of our study on the nuclear medium modifications of the meson electromagnetic form factors in the framework of the Nambu–Jona-Lasinio model with the help of the Schwinger proper-time regularization scheme to tame the loop divergence and simulate the effect of QCD confinement. In our current approach, the meson structure and nuclear medium are constructed in the same Nambu–Jona-Lasinio model at the quark level. We examine the free-space and in-medium charge radii of kaon and pion, the spacelike elastic electromagnetic form factors of kaon and pion, and their quark-sector form factors, which reflect their internal structures. By comparing our result to experimental data, we found that the free-space elastic electromagnetic form factors of the mesons are consistent with the data, while the in-medium elastic electromagnetic form factors of the mesons are found to decrease as the nuclear matter density increases, leading to a rise of meson charge radius, which is consistent with the prediction of other theoretical calculations. We also predict the axial nucleon coupling constant gA in nuclear medium computed via the Goldberger-Treiman relation, which is crucial for searching the neutrinoless double beta decay (0νββ). Published by the American Physical Society 2024

Onset of scaling violation in pion and kaon elastic electromagnetic form factors

Using a symmetry-preserving truncation of the quantum field equations describing hadron properties, parameter-free predictions are delivered for pion and kaon elastic electromagnetic form factors, FP=π,K, thereby unifying them with kindred results for nucleon elastic electromagnetic form factors. Regarding positive-charge states, the analysis stresses that the presence of scaling violations in QCD entails that Q2FP(Q2) should exhibit a single maximum on Q2>0. Locating such a maximum is both necessary and sufficient to establish the existence of scaling violations. The study predicts that, for charged π, K mesons, the Q2FP(Q2) maximum lies in the neighbourhood Q2≃5 GeV2. Foreseeable experiments will test these predictions and, providing their Q2 reach meets expectations, potentially also provide details on the momentum dependence of meson form factor scaling violation.

Measurement of Viscoelastic Properties by Free Loading-Mass Method

Background: A procedure for determining the elastic and viscous properties of the sample material on the basis of the forced vibrations of a sample of mass m loaded with a certain mass M is developed. One of advantages of using the top mass instead of a rigid fixation is the appearance of an additional deformation resonance, the frequency of which is < √ M / m times smaller than the resonance frequency of the fixed sample. Method: The experimental setup implementing the free mass method is described. Notably, the proposed scheme does not require any adjustment and is assembled from standard devices. By changing the design of the sample only, both shear and compression-tension strains can be measured. The combination of these methods allows measuring the complex Poisson’s ratio, in addition to modulus of elasticity and loss factor. Results: One-dimensional (1D) and two-dimensional (2D) models of specimen deformation are considered. For the 1D deformation model, approximate formulas for calculating the modulus of elasticity and the loss factor are substantiated and the limits of validity these formulas are outlined. Improving the accuracy of measurements is also considered. To do this, it is necessary to fully describe the boundary conditions on the deformable sample. The developed 2D model of sample deformation made it possible to calculate the elastic modulus form factors for various samples with axial symmetry. Conclusion: The method may become a Standard for measuring viscoelastic properties of materials (complex elastic and shear modulus, as well as complex Poisson's ratio).

WITHDRAWN: Accurate and efficient analytical simulation of free vibration for embedded nonlocal CNTRC beams with general boundary conditions

This study aims to evaluate the free vibrational response of restrained nanobeam enriched by nanocomposites based on an exact Fourier series approach. In order to capture the small size effects on the dynamical response, Eringen’s differential form of nonlocal elasticity is used which employs the one size (nonlocal) parameter. Within the framework of Rayleigh and Bernoulli-Euler beam theories to include the effect of nonlocality and by employing Fourier sine series together with Stokes’ transformation, a system of linear equations is obtained then solved by using the coefficient matrix. The combined effects of elastic boundary conditions, elastic medium, dispersion patterns and nonlocal effects are examined by solving this eigen-value problem constructed with Fourier infinite series. Free vibration frequencies are calculated for carbon nanotube reinforced nanobeam under different rigid or restrained boundary conditions, including an elastic medium Winkler-Pasternak type. A comprehensive parametric study is performed, with the particular focus on the influences of distribution pattern, elastic boundary and medium parameter on the free vibrational response of the composite nanobeam with different graded distributions. It is concluded that the addition of a small amount of carbon nanotube material can reinforce the stiffness of the nanobeam, and its free vibration performance is significantly affected by the distribution patterns, elastic medium and boundary conditions.

Indications for the Substantial Predominance of Short-Range Effects on Inelastic Coulomb Form Factors for Various States in the 26Mg Nucleus

Short-range effects on C2, C3, as well as C4 form factors in the 26Mg nucleus, were examined. The charge density distribution in this nucleus was also tested by means of one and two body fragments of cluster enlargement in cooperation with single-particle wave functions of harmonic potential. The correlation of Jastrow form was employed to inset the influence of short-range into the two body fragment of cluster enlargement. The nucleus of 26Mg was assumed to own a 16O-core with (A-16) nucleons dispersed over the sd-model space. The form factors in 26Mg nucleus ascend from the core-polarization and model space involvements. The form of Tassie model, subject to the charge density, was used to determine the transition density of core polarization. The one body density matrix elements required for determining the transition density of model space for various transitions in 26Mg were found via carrying out shell model computations using the OXBASH program with the universal-sd interaction of Wildenthal. The present calculations were subjected to the oscillator and correlation parameters symbolized by and respectively. These parameters are self-sufficiently generated for every specific nucleus by fitting between the calculated and observed elastic form factors. For determining the charge density, elastic form factors and inelastic Coulomb form factors for dissimilar excited states in 26Mg, one value is needed for and This study shows indications for the substantial predominance of short-range influences on current computations, where considering these influences look to be requisite for carrying out a distinguished adjustment in calculated results which ultimately leads to a remarkable explication of the data throughout all the considered momentum transfers.

Study of Nuclear Structure and Elastic Electron Scattering Form Factors for Neutron Halo Nuclei (22N ,23O and 24F) Using Full Correlation Functions with Two Size Parameters

The study of neutron-rich nuclei's form factors, root-mean-square radius (rms), and nuclear density distributions is the focus of this work for the nuclei (22N,23 O and 24F). With the use of a strong short-range effect and a strong tensor force, the nucleons distribution function of the two oscillating harmonic particles in a two-frequency shell model operates with two different parameters: the first (bcore), for the inner (core) orbits, and the second (bvalence) for the outer (halo) orbits. This work demonstrated the existence of neutron halo nuclei for the nuclei (22N, 23O and 24F) in the (2s1/2) shell. The computed density distribution of neutron, proton and matter for these nuclei displayed the long tail performance. Using the Borne approximation of the plane wave, the elastic form factor of the electron scattering from the alien nucleus was calculated, this form factor is independent of the neutrons that make up the halo, but rather it results from a difference in the proton density distribution of the last proton in the nuclei. Fortran 95 power station program was used to the neutron, proton and matter density, elastic electron scattering form factor, and rms radii. The calculated outcomes for these exotic nuclei were in good agreement with the experimental data.

Comparative experimental study of biomechanical features of suture materials in tendon repair

Introduction Many different suture configurations and pathomorphology of tendon repair have been described for tendon repair over the past 20 years. However, the biomechanical properties of suture material at primary flexor tendon repair have not been sufficiently explored. A cyclic loading test is performed to evaluate the performance of the different sutures under repeated loading conditions simulating dynamic conditions in postoperative rehabilitation procedures.The objective was to compare the strength of suture materials under cyclic loading on a biological model of a tendon.Material and methods Eighty porcine digital flexor tendons were examined in a pilot study. The sutured tendons were tested with a universal testing machine. Tendon repair was produced using polypropylene in group I, braided polyamide suture in group II, complex polytetrafluoroethylene thread in group III and a thread of superelastic titanium nickelide in group IV. The standard Chang protocol was used for cyclic loading.Results The percentage of intact sutures was 25 % in group I and in group II, 80 % in group III and 85 % in group IV after completing the entire load cycle. A pairwise comparison showed suture disruption being more common for group I and group II as compared to group III and group IV. Irreversible gap was more common for group 1 as compared to group IV. Neither knot ruptures nor tissue cutting were seen in the groups.Discussion The topic of biomechanical properties of suture material remains poorly understood. Although static load testing is commonly used in current experimental studies and cyclic testing is suitable for simulating postoperative conditions. The search continues for the “ideal” suture material for flexor tendon repair to prevent tears and retain tensile properties until the repair reaches strength.Conclusion The threads of polytetrafluoroethylene and nickelide-titanium showed the best biomechanical properties for tendon repair in the form of linear strength, good elasticity and low plasticity of the suture material. There were no significant differences between polypropylene and braided polyamide threads.

Multi-time scale dynamic operation optimization method for industrial park electricity-heat-gas integrated energy system considering demand elasticity

This study proposes a multi-time scale dynamic optimization (MSDO) method for ultra-short-term scheduling in industrial electricity-heat-gas integrated energy systems. The aim is to enhance the feasibility of scheduling schemes and to utilize flexibility potential. The MSDO method considers equipment response differences and demand fulfillment time disparities. The dynamic aspect is reflected in the supply-demand matching within the scheduling time window. A single-layer model with unified temporal granularity is constructed based on lag parameter identification. The study proposes various forms of energy demand elasticity, including steam networks and cumulative demand, and investigates the optimal minimum temporal granularity for scheduling. Case results demonstrate that the MSDO method effectively characterizes the multi-energy time lag of equipment. Compared with methods disregarding lag parameters, the MSDO method enhances total profit by ¥ 120711.42 and improves operation stability by 2.96%. The MSDO method outperforms baseline methods in cost and stability, accommodating a 160% increase in renewable energy growth. Under different elasticity spaces, the profit of the cumulative demand method exceeds that of the average method. The time lag of different equipment impacts scheduling profits. An optimal choice exists for the minimum temporal granularity to strike a balance between computational efficiency, economy, and feasibility.

Way to a Library of Ti-Series Oxide Nanofiber Sponges that are Highly Stretchable, Compressible, and Bendable.

Ti-series oxide ceramics in the form of aerogels, such as TiO2, SrTiO3, BaTiO3, and CaCu3Ti4O12, hold tremendous potential as functional materials owing to their excellent optical, dielectric, and catalytic properties. Unfortunately, these inorganic aerogels are usually brittle and prone to pulverization owing to weak inter-particulate interactions, resulting in restricted application performance and serious health risks. Herein, a novel strategy is reported to synthesize an elastic form of an aerogel-like, highly porous structure, in which activity-switchable Ti-series oxide sols transform from the metastable state to the active state during electrospinning, resulting in condensation and solidification at the whipping stage to obtain curled nanofibers. These curled nanofibers are further entangled when flying in the air to form a physically interlocked, elastic network mimicking the microstructure of high-elasticity hydrogels. This strategy provides a library of Ti-series oxide nanofiber sponges with unprecedented stretchability, compressibility, and bendability, possessing extensive opportunities for greener, safer, and broader applications as integrated or wearable functional devices. As a proof-of-concept demonstration, a new, elastic form of TiO2, composed of both "white" and "black" TiO2 nanofiber sponges, is constructed as spontaneous air-conditioning textiles in smart clothing, buildings, and vehicles, with unique bidirectional regulation of radiative cooling in summer and solar heating in winter.

Gain scheduled task space control of multi DOF machine tools with non-linear parallel kinematics

Machine tools with multiple degrees of freedom and parallel kinematics offer tremendous opportunities for new kind of processes but at the same time also a lot of control challenges. They are subject to uncertainties in the form of kinematic errors, elasticities and thermal deflections. Their kinematic non-linearity requires the application of model-based control concepts whose full effectiveness can only be unlocked through controls in the task space. In particular, kinematic singularities occur in forming machines such as presses, which make closed-loop control at corresponding operating points considerably more difficult. In this paper, we use the example of a servo-driven press with three ram degrees of freedom to show how parallel kinematic machine tools can be controlled via inverse differential kinematics models in task space and to what extent the controls can benefit from scheduled gain factors. The results are validated both simulatively and experimentally. In the experimental tests, three-dimensional tool paths are traced that can be used to carry out orbital forging processes. Furthermore, the example of a punch hole rolling process demonstrates that the ram pose is controlled more accurately, which also has positive effects on the resulting workpiece geometry. The performance of the developed gain scheduling task space control is compared with that of a robust and non-robust control with static gains.

Anisotropic mechanical properties of β-Ga2O3 single-crystal measured via angle-dependent nanoindentation using a Berkovich indenter

Load-dependent and angle-dependent nanoindentation tests were performed on a (2¯01)-oriented single-crystal β-Ga2O3 substrate to study the mechanical properties of the material. The anisotropy of the mechanical properties was examined, especially with regard to the dependence of the elastic modulus (E), hardness (H), and form of plastic deformation on the rotation angle of a Berkovich indenter with respect to the monoclinic structure. E reached a maximum value and H a minimum value when the sample was rotated to such an angle that one of the three facets of the Berkovich indenter was parallel to the [010] direction. To compare our experimental results with the theoretical calculation based on the monoclinic structure, the elastic surface of β-Ga2O3 was calculated using fourth-rank stiffness and compliance tensors and visualized in three-dimensional space. Two-dimensional sectional maps of the elastic surface were obtained for a range of crystal planes, and good agreement was obtained between the experimental observations and calculations. Plastic deformation at the indenter impressions was evaluated using scanning and transmission electron microscopy, and dislocations, cleavage, and cracks were observed. Their structure and density depended on the rotation angle. Our results clearly show a strong anisotropy of the mechanical properties of β-Ga2O3, which is very different from what is found in other compound semiconductors for power-device applications, such as GaN and 4H-SiC. This emphasizes the importance of customizing the machining process for β-Ga2O3, rather than simply using “machining recipes” for other materials.

Electromagnetic radii of the nucleon in soft-wall holographic QCD

We revisit the electromagnetic form factors of the proton and neutron in the original-minimal soft-wall holographic QCD, which has only two parameters, i.e., the mass scale κ and the twist parameter of the nucleon τ. We first fix τ=3 by the hard scattering rule, and extract κ=0.402 GeV from the world data (including the Mainz A1 data) of the Sachs magnetic form factor of the proton GMp. We then predict among others, the charge radius of the proton to be rp=0.831±0.008 fm, in perfect agreement with the recent charge radius of the proton measured by the PRad collaboration at Jefferson Lab, and in agreement with the muonic hydrogen experiments. Our prediction for the proton elastic form factor ratio μpGEp/GMp is also in very good agreement with the recent high precision Jefferson Lab recoil polarization experiment E08-007 for Q2=0.3−0.6 GeV2, and with the recent high precision Mainz A1 experiment for Q2<0.13 GeV2.

Electromagnetic form factors for nucleons in short-range correlations

Recent experimental studies have led to the suggestion that short-range correlations may be a major contributor to the nuclear EMC effect. This hypothesis requires that the structure function for nucleons involved in short-range correlations should be heavily suppressed compared to that of a free nucleon. Based on calculations performed within an AdS/QCD motivated, light-front quark-diquark model, we find that this large suppression of the nucleon structure function leads to a strong suppression of the nucleon elastic form factors.

METODOLOGI TEOLOGI AL ASY’ARY DAN PENGARUHNYA TERHADAP PENDIDIKAN ISLAM DI INDONESIA

The Indonesian understanding of Ahlus Sunnah Islam rests on the understanding of Asyariyah theology which is the basis for building the religious beliefs of the majority of Indonesian Muslims. This understanding of kalam or theology that was taught by Imam Ash'ari has given birth to a methodology of thinking that has a strong influence on various fields of Islamic religion, especially in the field of education. Al Asy'ari's moderate thinking style in translating the core teachings of Islam has influenced how traditional Islamic education in Indonesia takes an elastic and moderate form in responding to various social religious religious issues that are developing in Indonesia. Al Asyari's moderate style of thinking in time will also influence the development of educational institutions in Indonesia, especially madrasas which seek to eclecticly combine the Islamic scientific approach which is "turats al qadim" or old scientific traditions with western scientific approaches which are "turats al hadith" or a new scientific tradition. This study is intended to discuss the influence of the methodology of Islamic thought or Asyari theology in the field of education, especially its effect on traditional Islamic education in Indonesia, both in terms of teaching materials on aqeedah which are the subject matter of religious teachings and in terms of its institutional development in adapting to changing times in the present.

Electromagnetic form factors in a contact interaction: scalar and pseudoscalar mesons

The determination of fundamental properties of hadrons is important to clearly understand the experimental measurements such as the anomalous magnetic moment of the muon. However, since a first principle approach is hard to find, several groups among the world are approaching phenomenologically to such description of hadrons. In this poster, we present a comprehensive survey of electromagnetic form factors of all light, heavy and heavy-light ground-state pseudoscalar and scalar mesons. Specifically, in this work we are interested on the determination of Elastic Meson Form Factors (EFF) for Scalar (S) and Pseudoscalar (PS) mesons. However, the calculation of all EFF requires the computation of the quark propagator, the Bethe-Salpeter (BS) equation and the Bethe-Salpeter Amplitudes (BSA) of mesons, their masses as well as the knowledge of the quark-photon interaction at different probing momenta.

Medical Assistance in Dying (MAiD): Human and Humanity in The Study of Fiqh Maqașid

This study aimed to formulate the construction of fiqh maqașid as a standardization of the concept of humanity in Medical Assistance in Dying (MAiD). This study contributes to actualizing fiqh maqașid as a standardization of values in solving humanitarian problems. This is based on the phenomenon of MAiD, which is considered controversial in the eyes of social religion and state law as in the concept of Islamic law (fiqh), which sees that the protection and realization of human existence and humanity are essential values in the study of Islamic law (fiqh). This argumentation must be elaborated in depth regarding interests and benefit elements in the MAiD phenomenon. The stages of the realization of benefits in the context of the approach to Islamic law (fiqh) are one of the representations and forms of elasticity in the study of the objectives of Islamic law (maqașid al-sharia). The relevance of maqașid shari'ah studies as a form of maqașid fiqh approach is considered to carry urgency in determining aspects of benefit in the MAiD phenomenon and representing maqașid fiqh in realizing human protection and humanity. This study uses literature research with data from various phenomena and regulations on MAiD, which are presented descriptively and then critically analyzed through the fiqh maqașid approach. This study found that the realization of the MAiD program through euthanasia has implications for the non-realization of the essential values of maqașid shari'ah in fiqh maqașid. This study confirms that fiqh maqașid has an orientation towards solving human problems based on humanity

Electroexcitation Form Factors and Deformation of 20,22Ne Isotopes Based on the Shell Model and Hartree-Fock plus BCS Calculations

Nuclear structure of 20,22Ne isotopes has been studied via the shell model with Skyrme-Hartree-Fock calculations. In particular, the transitions to the low-lying positive and negative parity excited states have been investigated within three shell model spaces; sd for positive parity states, spsdpf large-basis (no-core), and zbme model spaces for negative parity states. Excitation energies, reduced transition probabilities, and elastic and inelastic form factors were estimated and compared to the available experimental data. Skyrme interaction was used to generate a one-body potential in the Hartree-Fock calculations for each selected excited states, which is then used to calculate the single-particle matrix elements. Skyrme interaction was used to calculate the radial wave functions of the single-particle matrix elements, from which a one-body potential in Hartree-Fock theory with SLy4 parametrization can be generated. Furthermore, we have explored the interplays among neutron and proton density profiles in two dimensions, along with the deformations of 20,22Ne using Hartree-Fock plus BCS calculations.

Form factors of the nucleon by using the t dependence of parton distribution functions

This paper calculates the elastic form factors for nucleons based on generalized parton distributions using an extended new ansatz introduced in http://dx.doi.org/10.1103/PhysRevC.105.025202 (Phys. Rev. C 105, no.2, 025202 (2022)). Different parton distribution functions (PDFs) are considered, and modifications are made to the free parameters of the new ansatz. The obtained results are systematically compared among the combinations of different PDFs and ansatzes for high ranges of momentum transfer, with $-t < 35 GeV^{-2}$. The minimum suitable parameters are used to parametrize the model. After obtaining the form factors, we proceed to compute the electric radius and the transversely unpolarized densities for the nucleon. In addition, we derive the parton distribution functions (PDFs) that depend on the impact parameter. Finally, we analyze the results by comparing them with the findings from other research and experimental data.