Journal articles: 'Beam family'

1

Tjong, Wong Foek, Nelvin Tanoyo, and Tonny C. Gosaria. "Free-Vibration and Buckling Analyses of Beams using Kriging-Based Timoshenko Beam Elements with the Discrete Shear Gap Technique." Civil Engineering Dimension 26, no. 1 (March 4, 2024): 21–31. http://dx.doi.org/10.9744/ced.26.1.21-31.

Full text

Abstract:

A family of locking-free Kriging-based Timoshenko beam elements with a new implementation of the discrete shear gap technique was recently developed (referred to as K-beam-DSG1 elements). Performance of the K-beam-DSG1 elements has been shown to be very satisfactory in the linear static analysis of beams for a wide variety of thicknesses. This paper presents further development of the K-beam-DSG1 elements to free vibration and bifurcation buckling analyses of prismatic and non-prismatic beams. Consistent Kriging-based mass matrices are used for free vibration analysis and similarly, consistent Kriging-based geometric stiffness matrices are used for buckling analysis. The results show that for most of the cases, the K-beam-DGS1 elements yield remarkably accurate natural frequencies and critical compressive loads using a reasonable number of elements to discretize the beam. For an axially functionally graded fixed-fixed supported beam, however, the elements fail to predict the critical load accurately.

APA, Harvard, Vancouver, ISO, and other styles

2

Alababneh, Nedal K. "Bessel Beams and Gaussian Beams as information carriers in free space optical interconnects systems: A comparison study." International Journal of Electrical and Computer Engineering (IJECE) 9, no. 5 (October 1, 2019): 3488. http://dx.doi.org/10.11591/ijece.v9i5.pp3488-3494.

Full text

Abstract:

<p><span style="font-family: Times New Roman;">We introduce a comparison study for the performance of a lens-based free space optical interconnects system assuming Bessel Beams and Gaussian Beams as information carriers. The optical field at the detector plane was derived for the two beam profiles. In both cases the expressions for the output optical filed are expressed in terms of complex Gaussian functions. The performance of the system for the two beams is evaluated and compared. Using simulation results we show that the use of Bessel beam gives superior results to that of using Gaussian beam for large interconnects distance.</span></p>

APA, Harvard, Vancouver, ISO, and other styles

3

Driessen, Koen, Pybe Faber, Kees Kooijman, Pepijn Kramer, Hugo van Leeuwen, and Pieter Schröder. "The FEI Small Dual Beam Product Family." Systems Research Forum 01, no. 01 (January 2006): 73–87. http://dx.doi.org/10.1142/s1793966606000138.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Hu, Zhongtao, Yaoheng Yang, Lu Xu, Yun Jing, and Hong Chen. "Airy beam-enabled binary acoustic metasurfaces (AB-BAM)." Journal of the Acoustical Society of America 153, no. 3_supplement (March 1, 2023): A140. http://dx.doi.org/10.1121/10.0018434.

Full text

Abstract:

Airy beams have offered great opportunities for ultrasound beam manipulation. However, one critical barrier that limits the broad applications of Airy beams in ultrasound is the lack of simply built device to generate Airy beams in water. This work presents a family of Airy beam-enabled binary acoustic metasurfaces (AB-BAMs) for underwater ultrasound beam manipulation. AB-BAMs are designed and fabricated by 3D printing with two coding bits: a polylactic acid unit acting as a bit “1” and a water unit acting as a bit “0.” The distribution of the binary units is determined by the pattern of Airy beam. We demonstrate the capability of AB-BAMs in flexibly tuning the focal region size and beam focusing in 3D space. The focal depth of AB-BAMs can be continuous and electronical tuned by adjusting the operating frequency of the planar transducer without replacing the AB-BAMs. The superimposing method is leveraged to enable the generation of complex acoustic fields. Furthermore, the proposed 3D-printed AB-BAMs are simple to design, easy to fabricate, and low-cost to produce with the capabilities to achieve tunable focal size, flexible 3D beam focusing, arbitrary multipoint focusing, and continuous steerability, which creates unprecedented potential for ultrasound beam manipulation.

APA, Harvard, Vancouver, ISO, and other styles

5

Bernardini, Giovanni, Fabio Cetta, and Luigi Morino. "A Novel Highly Accurate Finite-Element Family." International Journal of Aerospace Engineering 2017 (2017): 1–20. http://dx.doi.org/10.1155/2017/7293682.

Full text

Abstract:

A novel Nth order finite element for interior acoustics and structural dynamics is presented, with N arbitrarily large. The element is based upon a three-dimensional extension of the Coons patch technique, which combines high-order Lagrange and Hermite interpolation schemes. Numerical applications are presented, which include the evaluation of the natural frequencies and modes of vibration of (1) air inside a cavity (interior acoustics) and (2) finite-thickness beams and plates (structural dynamics). The numerical results presented are assessed through a comparison with analytical and numerical results. They show that the proposed methodology is highly accurate. The main advantages however are (1) its flexibility in obtaining different level of accuracy (p-convergence) simply by increasing the number of nodes, as one would do for h-convergence, (2) the applicability to arbitrarily complex configurations, and (3) the ability to treat beam- and shell-like structures as three-dimensional small-thickness elements.

APA, Harvard, Vancouver, ISO, and other styles

6

Ding, Chaoliang, Olga Korotkova, Dmitri Horoshko, Zhiguo Zhao, and Liuzhan Pan. "Evolution of Spatiotemporal Intensity of Partially Coherent Pulsed Beams with Spatial Cosine-Gaussian and Temporal Laguerre–Gaussian Correlations in Still, Pure Water." Photonics 8, no. 4 (April 2, 2021): 102. http://dx.doi.org/10.3390/photonics8040102.

Full text

Abstract:

A new family of partially coherent pulsed beams with spatial cosine-Gaussian and temporal Laguerre–Gaussian correlations, named spatial cosine-Gaussian and temporal Laguerre–Gaussian correlated Schell-model (SCTLGSM) pulsed beams, is introduced. An analytic propagation formula is derived for the SCTLGSM pulsed beam through the spatiotemporal ABCD optical system characterizing a continuous dispersive medium. As an example, the evolution of spatiotemporal intensity of the SCTLGSM pulsed beam in a still, pure water column is then investigated. It is found that the SCTLGSM pulsed beams simultaneously exhibit spatiotemporal self-splitting and self-focusing phenomena, which can be attributed to the special spatial/temporal coherence structures and the presence of pulse chirper in the source plane. The physical interpretation of the obtained phenomena is given. The results obtained in this paper will be of interest in underwater optical technologies, e.g., directed energy and communications.

APA, Harvard, Vancouver, ISO, and other styles

7

Pietro, Gabriele De, Gaetano Giunta, Salim Belouettar, and Erasmo Carrera. "A static analysis of three-dimensional sandwich beam structures by hierarchical finite elements modelling." Journal of Sandwich Structures & Materials 21, no. 7 (September 27, 2017): 2382–410. http://dx.doi.org/10.1177/1099636217732907.

Full text

Abstract:

A static analysis of three-dimensional sandwich beam structures using one-dimensional modelling approach is presented within this paper. A family of several one-dimensional beam elements is obtained by hierarchically expanding the displacements over the cross-section and letting the expansion order a free parameter. The finite element approximation order over the beam axis is also a formulation free parameter (linear, quadratic and cubic elements are considered). The principle of virtual displacements is used to obtain the problem weak form and derive the beam stiffness matrix and equivalent load vectors in a nuclear, generic form. Displacements and stresses are presented for different load and constraint configurations. Results are validated towards three-dimensional finite element solutions and experimental results. Sandwich beams present a three-dimensional stress state and higher-order models are necessary for an accurate description. Numerical investigations show that fairly good results with reduced computational costs can be obtained by the proposed finite element formulation.

APA, Harvard, Vancouver, ISO, and other styles

8

Topko, B., M. Balzer, A. Dierlamm, F. Ehrler, U. Husemann, R. Koppenhöfer, I. Perić, M. Pittermann, and J. Naumann. "Monolithic HV-CMOS sensors for a beam monitoring system of therapeutic ion beams." Journal of Instrumentation 19, no. 03 (March 1, 2024): C03043. http://dx.doi.org/10.1088/1748-0221/19/03/c03043.

Full text

Abstract:

Abstract Nowadays, cancer treatment with ion beam is well established and studied. This method allows to deposit the maximum dose to the tumor and minimize the damage to healthy tissue, due to the Bragg peak of the ion energy deposition near the end of the particle range. During the treatment, it is possible to provide volumetric dose delivery by changing the particle energy (penetration depth) and adjusting the beam position via a magnetic system. For the beam monitoring system, the precise measurement of the beam direction, shape and fluence in real time becomes crucial to provide effective and safe dose delivery to the tumor. Additionally, the system should work for beam intensities up to 1010 s-1 for protons, be tolerant to 1 MeV neutron equivalent fluences up to 1015 cm-2 per year and be to tolerant to magnetic fields (for MR-guided ion beam). The studies presented in this article are focused on the application of the HitPix sensor family with counting electronics and frame-based readout for such a beam monitoring system. The HitPix sensors are monolithic pixelated silicon sensors based on HV-CMOS technology and have been developed at the ASIC and Detector Lab (ADL, KIT). Recent measurements with ion beams and a multi-sensor readout as well as future developments are discussed.

APA, Harvard, Vancouver, ISO, and other styles

9

Bake, Abdulhakim, Weiyao Zhao, David Mitchell, Xiaolin Wang, Mitchell Nancarrow, and David Cortie. "Lamellae preparation for atomic-resolution STEM imaging from ion-beam-sensitive topological insulator crystals." Journal of Vacuum Science & Technology A 40, no. 3 (May 2022): 033203. http://dx.doi.org/10.1116/6.0001771.

Full text

Abstract:

Good specimen quality is a key factor in achieving successful scanning transmission electron microscope analysis. Thin and damage-free specimens are prerequisites for obtaining atomic-resolution imaging. Topological insulator single crystals and thin films in the chalcogenide family such as Sb2Te3 are sensitive to electron and ion beams. It is, therefore, challenging to prepare a lamella suitable for high-resolution imaging from these topological insulator materials using standard focused ion-beam instruments. We have developed a modified method to fabricate thin focused ion-beam (FIB) lamellae with minimal ion-beam damage and artifacts. The technique described in the current study enables the reliable preparation of high-quality transmission electron microscope (TEM) specimens necessary for studying ultra-thin surface regions. We have successfully demonstrated that the careful selection of FIB milling parameters at each stage minimizes the damage layer without the need for post-treatment.

APA, Harvard, Vancouver, ISO, and other styles

10

Magnucki, Krzysztof, and Ewa Magnucka-Blandzi. "Dynamic Stability of a Three-Layer Beam – Generalisation of the Sandwich Structure Theory." Acta Mechanica et Automatica 18, no. 1 (December 30, 2023): 1–7. http://dx.doi.org/10.2478/ama-2024-0001.

Full text

Abstract:

Abstract The work focuses on the dynamic stability problem of a simply supported three-layer beam subjected to a pulsating axial force. Two analytical models of this beam are developed: one model takes into account the non-linear hypothesis of cross-section deformation, and the other takes into account the standard “broken line” hypothesis. Displacements, strains and stresses for each model are formulated in detail. Based on the Hamilton principle, equations of motion are determined for each of these models. These systems of two differential equations for each model are approximately solved with the consideration of the axial pulsating force, and the fundamental natural frequencies, critical forces and the Mathieu equation are determined. Detailed studies are performed for an exemplary family of beams. The stable and unstable regions are calculated for the three pulsating load cases. The values of fundamental natural frequencies and critical forces of exemplary beams calculated from two models are compared.

APA, Harvard, Vancouver, ISO, and other styles

11

Soleymani, Atefeh, Hashem Jahangir, Maria Rashidi, Farid Fazel Mojtahedi, Michael Bahrami, and Ahad Javanmardi. "Damage Identification in Reinforced Concrete Beams Using Wavelet Transform of Modal Excitation Responses." Buildings 13, no. 8 (July 31, 2023): 1955. http://dx.doi.org/10.3390/buildings13081955.

Full text

Abstract:

This study focuses on identifying damage in reinforced concrete (RC) beams using time-domain modal testing and wavelet analysis. A numerical model of an RC beam was used to generate various damage scenarios with different severities and locations. Acceleration time histories were recorded for both damaged and undamaged structures. Two damage indices, DI_MW and DI_SW, derived from the wavelet analysis, were employed to determine the location and severity of the damage. The results showed that different wavelet families and specific mother wavelets had varying effectiveness in detecting damage. The Daubechies wavelet family (db2, db6, and db9) detected damage at the center and sides of the RC beams due to good time and frequency localization. The Biorthogonal wavelet family (bior2.8 and bior3.1) provided improved time–frequency resolution. The Symlets wavelet family (sym2 and sym7) offered a balanced trade-off between time and frequency localization. The Shannon wavelet family (shan1-0.5 and shan1-0.1) exhibited good time localization, while the Frequency B-Spline wavelet family (fbsp2-1-0.1) excelled in frequency localization. Certain combinations of mother wavelets, such as shan1-0.5 with the DI_SW index, were highly effective in detecting damage. The DI_SW index outperformed DI_MW across different numerical models. Selecting appropriate wavelet analysis techniques, particularly utilizing shan1-0.5 in the DI_SW, proved effective for detecting damage in RC beams.

APA, Harvard, Vancouver, ISO, and other styles

12

Chen, Chengshang, Yuhan Fang, Chichen Jang, Wenchi Chen, Hui-Chi Lin, and Hsingchih Liang. "Systematically Investigating the Structural Variety of Crystalline and Kaleidoscopic Vortex Lattices by Using Laser Beam Arrays." Applied Sciences 11, no. 17 (August 30, 2021): 8018. http://dx.doi.org/10.3390/app11178018.

Full text

Abstract:

We theoretically demonstrate that a family of vortex-lattice structures can be flexibly generated using a multi-beam interference approach. Numerical calculation presents a variety of crystalline and kaleidoscopic patterns. Based on the numerical analysis, we experimentally realized these structure beams by combining an amplitude mask with multiple apertures and a spiral phase plate. The excellent agreement between the experimental and theoretical results not only validates the presented method, but also manifests the structure of vortex lattices.

APA, Harvard, Vancouver, ISO, and other styles

13

Abramochkin, Eugeny G., Svetlana N. Khonina, and Roman V. Skidanov. "Three-Airy Beams, Their Propagation in the Fresnel Zone, the Autofocusing Plane Location, as Well as Generalizing Beams." Photonics 11, no. 4 (March 28, 2024): 312. http://dx.doi.org/10.3390/photonics11040312.

Full text

Abstract:

A family of 2D light fields consisting of the product of three Airy functions with linear arguments has been studied theoretically and experimentally. These fields, called three-Airy beams, feature a parameter shift and have a cubic phase and a super-Gaussian circular intensity in the far zone. Transformations of three-Airy beams in the Fresnel zone have been studied using theoretical, numerical, and experimental means. It has been shown that the autofocusing plane of a three-Airy beam is similar to the square root of the shift parameter. We also introduce generalized three-Airy beams containing nine free parameters, and obtain their Fourier transform in a closed form.

APA, Harvard, Vancouver, ISO, and other styles

14

Wang, Fosheng. "Bifurcation Problems for Generalized Beam Equations." Advances in Mathematical Physics 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/635731.

Full text

Abstract:

We investigate a class of bifurcation problems for generalized beam equations and prove that the one-parameter family of problems have exactly two bifurcation points via a unified, elementary approach. The proof of the main results relies heavily on calculus facts rather than such complicated arguments as Lyapunov-Schmidt reduction technique or Morse index theory from nonlinear functional analysis.

APA, Harvard, Vancouver, ISO, and other styles

15

Hjaji, Mohammed A., Hasan M. Nagiar, Moftah M. Krar, and Ezedine G. Allaboudi. "Exact finite beam element for open thin walled doubly symmetric members under torsional and warping moments." Journal of Structural Engineering & Applied Mechanics 4, no. 4 (December 31, 2021): 267–81. http://dx.doi.org/10.31462/jseam.2021.04267281.

Full text

Abstract:

Starting with total potential energy variational principle, the governing equilibrium coupled equations for the torsional-warping static analysis of open thin-walled beams under various torsional and warping moments are derived. The formulation captures shear deformation effects due to warping. The exact closed form solutions for torsional rotation and warping deformation functions are then developed for the coupled system of two equations. The exact solutions are subsequently used to develop a family of shape functions which exactly satisfy the homogeneous form of the governing coupled equations. A super-convergent finite beam element is then formulated based on the exact shape functions. Key features of the beam element developed include its ability to (a) eliminate spatial discretization arising in commonly used finite elements, and (e) eliminate the need for time discretization. The results based on the present finite element solution are found to be in excellent agreement with those based on exact solution and ABAQUS finite beam element solution at a small fraction of the computational and modelling cost involved.

APA, Harvard, Vancouver, ISO, and other styles

16

Wstawska, Iwona. "The influence of geometric imperfections on the stability of three-layer beams with foam core." Archives of Mechanical Technology and Materials 37, no. 1 (January 26, 2017): 65–69. http://dx.doi.org/10.1515/amtm-2017-0010.

Full text

Abstract:

Abstract The main objective of this work is the numerical analysis (FE analysis) of stability of three-layer beams with metal foam core (alumina foam core). The beams were subjected to pure bending. The analysis of the local buckling was performed. Furthermore, the influence of geometric parameters of the beam and material properties of the core (linear and non-linear model) on critical loads values and buckling shape were also investigated. The calculations were made on a family of beams with different mechanical properties of the core (elastic and elastic-plastic material). In addition, the influence of geometric imperfections on deflection and normal stress values of the core and the faces has been evaluated.

APA, Harvard, Vancouver, ISO, and other styles

17

Zhang, Yong, Guo Ning Qi, Yang Jian Ji, Li Wei Song, and Peng Jiang. "Modular Product Family Design for Pumping Unit Based on Design Structure Matrix." Advanced Materials Research 479-481 (February 2012): 2420–23. http://dx.doi.org/10.4028/www.scientific.net/amr.479-481.2420.

Full text

Abstract:

A new method was introduced in this paper, which would help to build the modular product family for pumping unit. Design Structure Matrix (DSM) was used in the process of the pumping unit’s module planning avoiding from the disadvantages of inconsistent rules and improper scale. Taking the case of the beam-pumping unit, some specific techniques were discussed in this paper such as DSM’s building, tearing and clustering as well as the analysis of their results. And the product family of this kind of beam-pumping unit was designed under the result of the modules and the principle of tabular layouts of article characteristics. This study could be widely used as a kind of quantitative method for modular design of other products.

APA, Harvard, Vancouver, ISO, and other styles

18

Barrios, Ricardo, and Federico Dios. "Exponentiated Weibull distribution family under aperture averaging for Gaussian beam waves." Optics Express 20, no. 12 (May 25, 2012): 13055. http://dx.doi.org/10.1364/oe.20.013055.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Yura, H. T., and T. S. Rose. "Exponentiated Weibull distribution family under aperture averaging Gaussian beam waves: comment." Optics Express 20, no. 18 (August 23, 2012): 20680. http://dx.doi.org/10.1364/oe.20.020680.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Lin, Guoguang, and Boshi Chen. "A Family of Global Attractors for the Generalized Kirchhoff-Beam Equations." Journal of Applied Mathematics and Physics 11, no. 07 (2023): 1945–63. http://dx.doi.org/10.4236/jamp.2023.117126.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

CHESSA, P., M. GALIMBERTI, A. BARBINI, C. N. DANSON, A. GIULIETTI, D. GIULIETTI, and L. GIZZI. "Phase measurements without interferometry: 2D transverse phase detection by numerical beam intensity analysis." Laser and Particle Beams 17, no. 4 (October 1999): 681–92. http://dx.doi.org/10.1017/s0263034699174135.

Full text

Abstract:

A whole family of laser-plasma interaction experiments is based on the phase analysis of the laser pulse after the propagation in a plasma. Typically, this phase is obtained by means of interferometry. As pulsed interferometry is a much more difficult task than taking simple images of the beam, we developed a numerical code for extracting phase information from images. The technique, based on the algorithm of Gerchberg–Saxton, showed to be very effective in retrieving 2D phase distributions of simulated as well as real beams. The convergence of the algorithm is fast (some minutes on a personal computer). The electronic noise in real images is intrinsically discarded by the algorithm.

APA, Harvard, Vancouver, ISO, and other styles

22

Zuyev, Alexander, and Oliver Sawodny. "Stabilization and Observability of a Rotating Timoshenko Beam Model." Mathematical Problems in Engineering 2007 (2007): 1–19. http://dx.doi.org/10.1155/2007/57238.

Full text

Abstract:

A control system describing the dynamics of a rotating Timoshenko beam is considered. We assume that the beam is driven by a control torque at one of its ends, and the other end carries a rigid body as a load. The model considered takes into account the longitudinal, vertical, and shear motions of the beam. For this distributed parameter system, we construct a family of Galerkin approximations based on solutions of the homogeneous Timoshenko beam equation. We derive sufficient conditions for stabilizability of such finite dimensional system. In addition, the equilibrium of the Galerkin approximation considered is proved to be stabilizable by an observer-based feedback law, and an explicit control design is proposed.

APA, Harvard, Vancouver, ISO, and other styles

23

Wilt, Christopher, Jordan Thayer, and Wheeler Ruml. "A Comparison of Greedy Search Algorithms." Proceedings of the International Symposium on Combinatorial Search 1, no. 1 (August 25, 2010): 129–36. http://dx.doi.org/10.1609/socs.v1i1.18182.

Full text

Abstract:

We discuss the relationships between three approaches to greedy heuristic search: best-first, hill-climbing, and beam search. We consider the design decisions within each family and point out their oft-overlooked similarities. We consider the following best-first searches: weighted A*, greedy search, ASeps, window A* and multi-state commitment k-weighted A*. For hill climbing algorithms, we consider enforced hill climbing and LSS-LRTA*. We also consider a variety of beam searches, including BULB and beam-stack search. We show how to best configure beam search in order to maximize robustness. An empirical analysis on six standard benchmarks reveals that beam search and best-first search have remarkably similar performance, and outperform hill-climbing approaches in terms of both time to solution and solution quality. Of these, beam search is preferable for very large problems and best first search is better on problems where the goal cannot be reached from all states.

APA, Harvard, Vancouver, ISO, and other styles

24

Li, Tianyu. "A (3,2) high order zigzag beam element: A unified zigzag function family." Composite Structures 208 (January 2019): 847–64. http://dx.doi.org/10.1016/j.compstruct.2018.09.079.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Peter Marius, Lina Stephanie Winnie. "Conceptual Framework of B40 Women’s Entrepreneurial Intention in Malaysia using Theory of Planned Behavior." International Student Conference on Business, Education, Economics, Accounting, and Management (ISC-BEAM) 1, no. 1 (March 9, 2024): 910–19. http://dx.doi.org/10.21009/isc-beam.011.63.

Full text

Abstract:

Despite Malaysia's rapid economic growth, a substantial income gap persists, and women-owned businesses remain a minority. The study employs the Theory of Planned Behavior to create a conceptual framework for understanding the factors that influence B40 women's entrepreneurial intentions. It examines the effect of attitude towards entrepreneurship, family support, and entrepreneurial self-efficacy as crucial drivers of women's decisions to engage in entrepreneurship. The research methodology will involve using questionnaires that will be distributed to a diverse sample of B40 women in Malaysia. The implications of the study include contributing to Malaysia's National Entrepreneurship Policy, enhancing support for women entrepreneurs, and motivating more women, particularly those with unstable incomes, to pursue entrepreneurship, thereby fostering greater gender equality and economic development.

APA, Harvard, Vancouver, ISO, and other styles

26

Giunta, Gaetano, Salim Belouettar, Olivier Polit, Laurent Gallimard, Philippe Vidal, and Michele D’ottavio. "Hierarchical Beam Finite Elements Based Upon a Variables Separation Method." International Journal of Applied Mechanics 08, no. 02 (March 2016): 1650026. http://dx.doi.org/10.1142/s1758825116500265.

Full text

Abstract:

A family of hierarchical one-dimensional beam finite elements developed within a variables separation framework is presented. A Proper Generalized Decomposition (PGD) is used to divide the global three-dimensional problem into two coupled ones: one defined on the cross-section space (beam modeling kinematic approximation) and one belonging to the axis space (finite element solution). The displacements over the cross-section are approximated via a Unified Formulation (UF). A Lagrangian approximation is used along the beam axis. The resulting problems size is smaller than that of the classical equivalent finite element solution. The approach is, then, particularly attractive for higher-order beam models and refined axial meshes. The numerical investigations show that the proposed method yields accurate yet computationally affordable three-dimensional displacement and stress fields solutions.

APA, Harvard, Vancouver, ISO, and other styles

27

Parker, Kevin J., and Miguel A. Alonso. "The Spherical Harmonic Family of Beampatterns." Acoustics 4, no. 4 (November 15, 2022): 958–66. http://dx.doi.org/10.3390/acoustics4040059.

Full text

Abstract:

The free space solution to the wave equation in spherical coordinates is well known as a separable product of functions. Re-examination of these functions, particularly the sums of spherical Bessel and harmonic functions, reveals behaviors which can produce a range of useful beampatterns from radially symmetric sources. These functions can be modified by several key parameters which can be adjusted to produce a wide-ranging family of beampatterns, from the axicon Bessel beam to a variety of unique axial and lateral forms. We demonstrate that several special properties of the simple sum over integer orders of spherical Bessel functions, and then the sum of their product with spherical harmonic functions specifying the free space solution, lead to a family of useful beampatterns and a unique framework for designing them. Examples from a simulation of a pure tone 5 MHz ultrasound configuration demonstrate strong central axis concentration, and the ability to modulate or localize the axial intensity with simple adjustment of the integer orders and other key parameters related to the weights and arguments of the spherical Bessel functions.

APA, Harvard, Vancouver, ISO, and other styles

28

XIA, HUI, GANG TANG, KUI HAN, DA-PENG HAO, HUA CHEN, and LEI-MING ZHANG. "SCALING APPROACH TO ANOMALOUS SURFACE ROUGHENING OF THE (d+1)-DIMENSIONAL MOLECULAR-BEAM EPITAXY GROWTH EQUATIONS." Modern Physics Letters B 20, no. 30 (December 30, 2006): 1935–41. http://dx.doi.org/10.1142/s0217984906012249.

Full text

Abstract:

To determine anomalous dynamic scaling of continuum growth equations, López12 proposed an analytical approach, which is based on the scaling analysis introduced by Hentschel and Family.15 In this work, we generalize this scaling analysis to the (d+1)-dimensional molecular-beam epitaxy equations to determine their anomalous dynamic scaling. The growth equations studied here include the linear molecular-beam epitaxy (LMBE) and Lai–Das Sarma–Villain (LDV). We find that both the LMBE and LDV equations, when the substrate dimension d>2, correspond to a standard Family–Vicsek scaling, however, when d<2, exhibit anomalous dynamic roughening of the local fluctuations of the growth height. When the growth equations exhibit anomalous dynamic scaling, we obtain the local roughness exponents by using scaling relation α loc =α-zκ, which are consistent with the corresponding numerical results.

APA, Harvard, Vancouver, ISO, and other styles

29

Bellucci, Valerio, Gianfranco Paternò, Riccardo Camattari, Vincenzo Guidi, Michael Jentschel, and Pierre Bastie. "High-efficiency diffraction and focusing of X-rays through asymmetric bent crystalline planes." Journal of Applied Crystallography 48, no. 1 (January 30, 2015): 297–300. http://dx.doi.org/10.1107/s1600576714024960.

Full text

Abstract:

The grooving technique was employed for manufacturing a self-standing curved Ge crystal. The crystal focuses hard X-rays with high efficiency by diffraction in Laue geometry through asymmetric bent planes. The sample was tested at the Institut Laue–Langevin (Grenoble, France), undergoing two types of characterization. A monochromatic and low-divergence γ-ray beam was used to test the curvature of asymmetric planes, showing a diffraction performance better than for any mosaic crystal under equal conditions. Then, the focusing capability of the crystal was probed through a polychromatic and fine-focus hard X-ray beam. Asymmetric (220) planes were chosen for analysis because of the impossibility of obtaining a curvature along this family of planesviaany symmetric configuration in focusing crystals. A method for calculating the curvatures induced in any family of lattice planes is also presented.

APA, Harvard, Vancouver, ISO, and other styles

30

Kotlyar, Victor V., Sergey S. Stafeev, Vladislav D. Zaitsev, and Alexey M. Telegin. "Poincaré Beams at the Tight Focus: Inseparability, Radial Spin Hall Effect, and Reverse Energy Flow." Photonics 9, no. 12 (December 11, 2022): 969. http://dx.doi.org/10.3390/photonics9120969.

Full text

Abstract:

The family of Poincaré beams has three parameters, including two real-valued angular parameters, which specify a definite polarization state on the Poincaré sphere, and a third integer parameter n specifying the beam singularity order. We show theoretically and through a numerical simulation that, while being inseparable and not allowing for the separation of polarization and orbital degrees of freedom in the general case, the Poincaré beams display remarkable properties when tightly focused. We find that at n = 2, a reverse energy flow occurs near the optical axis, which is mathematically expressed as the negative projection of the Poynting vector. We also reveal that given certain parameters of the Poincaré beams, the energy flow rotates around the optical axis due to spin–orbital conversion. We also reveal a radial optical Hall effect that occurs at the tight focus of Poincaré beams, when the on-axis components of the spin angular momentum vector have different signs on certain different-radius circles centered at the focal spot center.

APA, Harvard, Vancouver, ISO, and other styles

31

McKibben, Mark A. "Measure-Dependent Stochastic Nonlinear Beam Equations Driven by Fractional Brownian Motion." International Journal of Stochastic Analysis 2013 (December 31, 2013): 1–16. http://dx.doi.org/10.1155/2013/868301.

Full text

Abstract:

We study a class of nonlinear stochastic partial differential equations arising in the mathematical modeling of the transverse motion of an extensible beam in the plane. Nonlinear forcing terms of functional-type and those dependent upon a family of probability measures are incorporated into the initial-boundary value problem (IBVP), and noise is incorporated into the mathematical description of the phenomenon via a fractional Brownian motion process. The IBVP is subsequently reformulated as an abstract second-order stochastic evolution equation driven by a fractional Brownian motion (fBm) dependent upon a family of probability measures in a real separable Hilbert space and is studied using the tools of cosine function theory, stochastic analysis, and fixed-point theory. Global existence and uniqueness results for mild solutions, continuous dependence estimates, and various approximation results are established and applied in the context of the model.

APA, Harvard, Vancouver, ISO, and other styles

32

Liao, Yuhuai, Guoguang Lin, and Jie Liu. "A Family of Inertial Manifolds for a Class of Generalized Kirchhoff-Beam Equations." Journal of Applied Mathematics and Physics 10, no. 07 (2022): 2153–63. http://dx.doi.org/10.4236/jamp.2022.107147.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Liao, Yuhuai, Guoguang Lin, and Jie Liu. "A Family of Global Attractors for a Class of Generalized Kirchhoff-Beam Equations." Journal of Applied Mathematics and Physics 10, no. 03 (2022): 930–51. http://dx.doi.org/10.4236/jamp.2022.103064.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Lin, Guoguang, and Jie Liu. "A Random Attractor Family of the High Order Beam Equations with White Noise." International Journal of Modern Nonlinear Theory and Application 09, no. 03 (2020): 51–61. http://dx.doi.org/10.4236/ijmnta.2020.93004.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Rychter, Zenon. "A family of shear-deformation beam theories and a refined Bernoulli-Euler theory." International Journal of Engineering Science 31, no. 4 (April 1993): 559–67. http://dx.doi.org/10.1016/0020-7225(93)90049-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Ray, Michael E., Rodney L. Dunn, Kathleen A. Cooney, and Howard M. Sandler. "Family history of prostate cancer and relapse after definitive external beam radiation therapy." International Journal of Radiation Oncology*Biology*Physics 57, no. 2 (October 2003): 371–76. http://dx.doi.org/10.1016/s0360-3016(03)00504-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Tayşi, N., M. T. Göĝüş, and M. Özakça. "Structural Analysis of Arches in Plane with a Family of Simple and Accurate Curved Beam Elements Based on Mindlin-Reissner Model." Journal of Mechanics 27, no. 1 (March 2011): 129–38. http://dx.doi.org/10.1017/jmech.2011.14.

Full text

Abstract:

ABSTRACTIn this paper, the basic finite element formulation of a newly developed family of variable thickness, curved,C(0) continuity Mindlin-Reissner model curved beam elements which include shear deformation and rotatory inertia effects is presented. The accuracy, convergence and efficiency of these newly developed curved beam elements are explored through a series of analyses of arch structures and the results are compared with those obtained by other analytical and numerical methods. The comparisons show that the method yields very good results with a relatively small number of elements.

APA, Harvard, Vancouver, ISO, and other styles

38

Aouadi, Moncef. "Regularity and upper semicontinuity of pullback attractors for non-autonomous Rao–Nakra beam." Nonlinearity 35, no. 4 (February 18, 2022): 1773–809. http://dx.doi.org/10.1088/1361-6544/ac5098.

Full text

Abstract:

Abstract In this paper we study the long-time dynamics of a non-autonomous Rao–Nakra sandwich beam. The governing equations of Rao–Nakra sandwich beam consist of two wave equations for the longitudinal displacements of the top and bottom layers, and one Euler–Bernoulli beam equation for the transversal displacement. Under quite general assumptions on nonlinear damping and sources terms and based on nonlinear semigroups and the theory of monotone operators, we establish existence and uniqueness of weak and strong solutions. We also establish a Lipschitz stability result. We prove the existence of pullback attractors in natural space energy. Finally, we prove the regularity of the family of pullback attractors and its upper semicontinuous with respect to the fractional exponent γ ∈ (0, 1/2).

APA, Harvard, Vancouver, ISO, and other styles

39

Romero, P. C., and A. S. Ostrovsky. "Goos-Hänchen effect on a one transverse dimensional Hermite-Gaussian Beam." Revista Mexicana de Física 65, no. 2 (March 26, 2019): 175. http://dx.doi.org/10.31349/revmexfis.65.175.

Full text

Abstract:

We study the lateral displacement (Goos-H\"{a}nchen effect) of a Hermite-Gaussian beam incident on a dielectric interface of lower index of refraction than the incident media. Unlike previous results on the same subject, the present result can be applied to an infinite family of higher order solutions (or modes) of the Huygens-Fresnel integral. The final theoretical expression is valid for values that are close to the critical angle $\theta_{c}$. Discussion is made for the behavior of the lateral displacement for different modes of the Hermite-Gaussian beam.

APA, Harvard, Vancouver, ISO, and other styles

40

Newbury, Dale E., and Nicholas W. M. Ritchie. "Quantitative Electron-Excited X-Ray Microanalysis of Borides, Carbides, Nitrides, Oxides, and Fluorides with Scanning Electron Microscopy/Silicon Drift Detector Energy-Dispersive Spectrometry (SEM/SDD-EDS) and NIST DTSA-II." Microscopy and Microanalysis 21, no. 5 (September 14, 2015): 1327–40. http://dx.doi.org/10.1017/s1431927615014993.

Full text

Abstract:

AbstractA scanning electron microscope with a silicon drift detector energy-dispersive X-ray spectrometer (SEM/SDD-EDS) was used to analyze materials containing the low atomic number elements B, C, N, O, and F achieving a high degree of accuracy. Nearly all results fell well within an uncertainty envelope of ±5% relative (where relative uncertainty (%)=[(measured−ideal)/ideal]×100%). Quantification was performed with the standards-based “k-ratio” method with matrix corrections calculated based on the Pouchou and Pichoir expression for the ionization depth distribution function, as implemented in the NIST DTSA-II EDS software platform. The analytical strategy that was followed involved collection of high count (>2.5 million counts from 100 eV to the incident beam energy) spectra measured with a conservative input count rate that restricted the deadtime to ~10% to minimize coincidence effects. Standards employed included pure elements and simple compounds. A 10 keV beam was employed to excite the K- and L-shell X-rays of intermediate and high atomic number elements with excitation energies above 3 keV, e.g., the Fe K-family, while a 5 keV beam was used for analyses of elements with excitation energies below 3 keV, e.g., the Mo L-family.

APA, Harvard, Vancouver, ISO, and other styles

41

Khoury, A., J. H. Siewerdsen, C. M. Whyne, M. J. Daly, H. J. Kreder, D. J. Moseley, and D. A. Jaffray. "Intraoperative cone-beam CT for image-guided tibial plateau fracture reduction." Computer Aided Surgery 12, no. 4 (July 2007): 195–207. http://dx.doi.org/10.1080/10929080701526872.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Balch, C. D., and C. R. Steele. "Asymptotic Solutions for Warping and Distortion of Thin-Walled Box Beams." Journal of Applied Mechanics 54, no. 1 (March 1, 1987): 165–73. http://dx.doi.org/10.1115/1.3172953.

Full text

Abstract:

The equations of conventional thin plate theory are used to formulate an eigenvalue problem for effects of self-equilibrating end loads in thin-walled rectangular cross section tubes, or box beams. The problem is analyzed by a perturbation procedure, which is based on a small parameter proportional to the square root of the ratio of wall thickness to cross section width. Solution of the unperturbed problem yields a family of membrane and inextensional end-effect eigenfunctions which are found to have decay distances on the order of the beam width or shorter. The perturbation procedure is carried out to obtain closed form asymptotically valid solutions for warping and distortional effects which decay much more slowly. These asymptotic solutions compare favorably with previous analytical and experimental results.

APA, Harvard, Vancouver, ISO, and other styles

43

Akram, Saima, Faiza Akram, Moin-ud-Din Junjua, Misbah Arshad, and Tariq Afzal. "A Family of Optimal Eighth Order Iteration Functions for Multiple Roots and Its Dynamics." Journal of Mathematics 2021 (March 15, 2021): 1–18. http://dx.doi.org/10.1155/2021/5597186.

Full text

Abstract:

In this manuscript, we present a new general family of optimal iterative methods for finding multiple roots of nonlinear equations with known multiplicity using weight functions. An extensive convergence analysis is presented to verify the optimal eighth order convergence of the new family. Some special cases of the family are also presented which require only three functions and one derivative evaluation at each iteration to reach optimal eighth order convergence. A variety of numerical test functions along with some real-world problems such as beam designing model and Van der Waals’ equation of state are presented to ensure that the newly developed family efficiently competes with the other existing methods. The dynamical analysis of the proposed methods is also presented to validate the theoretical results by using graphical tools, termed as the basins of attraction.

APA, Harvard, Vancouver, ISO, and other styles

44

Rocha, J. C. A., D. G. Pires, M. R. L. Motta, N. M. Litchinitser, S. S. Vianna, E. J. S. Fonseca, and J. Ferraz. "Controlled conversion of transverse symmetries in a four-wave mixing process." Journal of Optics 24, no. 4 (March 10, 2022): 045505. http://dx.doi.org/10.1088/2040-8986/ac57b2.

Full text

Abstract:

Abstract Precise light manipulation in optical media has been important for developing new communication protocols, particle tracking and control, environmental sensing and quantum computing, to cite a few applications. Here, we explore the nonlinear light-matter interactions of Hermite-Gaussian (HG) beams with a rubidium vapor. We analytically and numerically predict the possibility of generating a nearly pure optical HG mode as a result of the four-wave mixing of two different HG modes. In contrast, four-wave mixing of other linear solutions of the paraxial wave equation in a third-order nonlinear medium results in the up-converted beam consisting of a superposition of multiple modes. In addition, we identify a large family of solutions of the paraxial wave equation, including cylindrical and elliptical modes, that can be generated in the process of the four-wave mixing by precisely adjusting the weights of the input HG beams. This study may find applications in the development of new classical and quantum optical sources, with more spatial versatility.

APA, Harvard, Vancouver, ISO, and other styles

45

Schellingerhout, Sander G., Eline J. de Jong, Maksim Gomanko, Xin Guan, Yifan Jiang, Max S. M. Hoskam, Jason Jung, et al. "Growth of PbTe nanowires by molecular beam epitaxy." Materials for Quantum Technology 2, no. 1 (February 22, 2022): 015001. http://dx.doi.org/10.1088/2633-4356/ac4fba.

Full text

Abstract:

Abstract Advances in quantum technology may come from the discovery of new materials systems that improve the performance or allow for new functionality in electronic devices. Lead telluride (PbTe) is a member of the group IV–VI materials family that has significant untapped potential for exploration. Due to its high electron mobility, strong spin–orbit coupling and ultrahigh dielectric constant it can host few-electron quantum dots and ballistic quantum wires with opportunities for control of electron spins and other quantum degrees of freedom. Here, we report the fabrication of PbTe nanowires by molecular beam epitaxy. We achieve defect-free single crystalline PbTe with large aspect ratios up to 50 suitable for quantum devices. Furthermore, by fabricating a single nanowire field effect transistor, we attain bipolar transport, extract the bandgap and observe Fabry–Pérot oscillations of conductance, a signature of quasiballistic transmission.

APA, Harvard, Vancouver, ISO, and other styles

46

Hui, Y., G. De Pietro, G. Giunta, S. Belouettar, H. Hu, E. Carrera, and A. Pagani. "Geometrically Nonlinear Analysis of Beam Structures via Hierarchical One-Dimensional Finite Elements." Mathematical Problems in Engineering 2018 (November 27, 2018): 1–22. http://dx.doi.org/10.1155/2018/4821385.

Full text

Abstract:

The formulation of a family of advanced one-dimensional finite elements for the geometrically nonlinear static analysis of beam-like structures is presented in this paper. The kinematic field is axiomatically assumed along the thickness direction via a Unified Formulation (UF). The approximation order of the displacement field along the thickness is a free parameter that leads to several higher-order beam elements accounting for shear deformation and local cross-sectional warping. The number of nodes per element is also a free parameter. The tangent stiffness matrix of the elements is obtained via the Principle of Virtual Displacements. A total Lagrangian approach is used and Newton-Raphson method is employed in order to solve the nonlinear governing equations. Locking phenomena are tackled by means of a Mixed Interpolation of Tensorial Components (MITC), which can also significantly enhance the convergence performance of the proposed elements. Numerical investigations for large displacements, large rotations, and small strains analysis of beam-like structures for different boundary conditions and slenderness ratios are carried out, showing that UF-based higher-order beam theories can lead to a more efficient prediction of the displacement and stress fields, when compared to two-dimensional finite element solutions.

APA, Harvard, Vancouver, ISO, and other styles

47

Adolphs, Nicolai, Weichen Liu, Erwin Keeve, and Bodo Hoffmeister. "Craniomaxillofacial surgery planning based on 3D models derived from Cone-Beam CT data." Computer Aided Surgery 18, no. 5-6 (May 10, 2013): 101–8. http://dx.doi.org/10.3109/10929088.2013.796002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Hidaka, Takako, Hideki Chuman, and Nobuhisa Nao-i. "Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy." Case Reports in Ophthalmology 7, no. 2 (June 13, 2016): 315–19. http://dx.doi.org/10.1159/000446603.

Full text

Abstract:

Herein, we report a case of nontraumatic bilateral rhegmatogenous retinal detachment (RRD) during external beam radiotherapy for nonocular tumor, presented as an observational case study in conjunction with a review of the relevant literature. A 65-year-old male was referred to our hospital due to bilateral RRD. He underwent a biopsy for a tumor of the left frontal lobe 4 months prior to presentation, and the tumor had been diagnosed as primary central nerve system B-cell type lymphoma. He received chemotherapy and external beam radiotherapy for 1 month. There were no traumatic episodes. Bilateral retinal detachment occurred during a series of radiotherapies. Simultaneous nontraumatic bilateral retinal detachment is rare. The effects of radiotherapy on ocular functionality, particularly in cases involving retinal adhesion and vitreous contraction, may include RRD. Thus, it is necessary to closely monitor the eyes of patients undergoing radiotherapy, particularly those undergoing surgery for retinal detachment and those with a history of photocoagulation for retinal tears, a relevant family history, or risk factors known to be associated with RRD.

APA, Harvard, Vancouver, ISO, and other styles

49

Forastiere, M. A., and G. C. Righini. "A family of curved Fresnel lenses for integrated optics: modelling by the beam propagation method." Pure and Applied Optics: Journal of the European Optical Society Part A 3, no. 3 (May 1994): 291–300. http://dx.doi.org/10.1088/0963-9659/3/3/013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Liu, Jian-Wei, Jie Xu, Yong Ni, Feng-Jia Fan, Chuan-Ling Zhang, and Shu-Hong Yu. "A Family of Carbon-Based Nanocomposite Tubular Structures Created by in Situ Electron Beam Irradiation." ACS Nano 6, no. 5 (May 2, 2012): 4500–4507. http://dx.doi.org/10.1021/nn301310m.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Beam family'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles