Log in

Relevant bibliographies by topics / Guided wave mixing / Journal articles

Journal articles on the topic 'Guided wave mixing'

To see the other types of publications on this topic, follow the link: Guided wave mixing.

Author: Grafiati

Published: 10 December 2022

Last updated: 28 January 2023

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

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Guided wave mixing.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Stegeman, G., C. Seaton, and C. Karaguleff. "Degenerate four-wave mixing with guided waves." IEEE Journal of Quantum Electronics 22, no. 8 (August 1986): 1344–48. http://dx.doi.org/10.1109/jqe.1986.1073117.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Pineda Allen, Juan Carlos Pineda, and Ching Tai Ng. "Mixing of Non-Collinear Lamb Wave Pulses in Plates with Material Nonlinearity." Sensors 23, no. 2 (January 8, 2023): 716. http://dx.doi.org/10.3390/s23020716.

Full text

Abstract:

Guided waves have been extensively studied in the past few years, and more recently nonlinear guided waves have attracted significant research interest for their potential for early damage detection and material state characterization. Combined harmonic generation due to wave mixing can offer some advantages over second harmonic generation. However, studies focused on Lamb wave mixing are still very limited, and have mainly focused on collinear wave mixing and used plane wave assumption. In this paper, numerical simulations and experiments are conducted to understand the interaction of mixing non-collinear Lamb wave pulses with non-planar wavefronts. The results demonstrate that the generated secondary wave is cumulative under internal resonance conditions and the sum-frequency component of the combined harmonics is useful for characterizing material nonlinearities.

APA, Harvard, Vancouver, ISO, and other styles

3

Trutschel, U., U. Langbein, F. Lederer, and H. Ponath. "Optical bistability in three-wave-mixing processes with guided waves." IEEE Journal of Quantum Electronics 21, no. 10 (October 1985): 1639–43. http://dx.doi.org/10.1109/jqe.1985.1072558.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Pineda Allen, Juan Carlos, and Ching Tai Ng. "Nonlinear Guided-Wave Mixing for Condition Monitoring of Bolted Joints." Sensors 21, no. 15 (July 27, 2021): 5093. http://dx.doi.org/10.3390/s21155093.

Full text

Abstract:

Bolted joints are fundamental to numerous structural components in engineering practice. Nevertheless, their failure or even their loosening can lead to insufficient performance and reduced structural safety. This study presents a theoretical development and experimental investigation into nonlinear guided-wave mixing for integrity monitoring of bolted joints in plates. Combinational harmonics generated due to nonlinear Lamb wave mixing and contact acoustic nonlinearity at the bolted joints were used to evaluate the applied torque level in the joint. The area of the power spectral density in the region of the sum combinational harmonic bandwidth is found to be highly correlated to the applied torque level at the joint. Moreover, the effect of the number of cycles and thus the time duration of the excitation is investigated. The results show that the combinational harmonics remain robust for different numbers of cycles in detecting bolt loosening. The findings presented in this study also provide physical insight into the phenomena of nonlinear Lamb wave mixing for evaluating applied torque in bolted joints, and the results help further advance the use of nonlinear guided waves for damage detection.

APA, Harvard, Vancouver, ISO, and other styles

5

Park, Junpil, Jeongseok Choi, and Jaesun Lee. "A Feasibility Study for a Nonlinear Guided Wave Mixing Technique." Applied Sciences 11, no. 14 (July 16, 2021): 6569. http://dx.doi.org/10.3390/app11146569.

Full text

Abstract:

Ultrasonic non-destructive testing is an effective means of examining objects without destroying them. Among such testing, ultrasonic nonlinear evaluation is used to detect micro-damage, such as corrosion or plastic deformation. In terms of micro-damage evaluation, the data that comes from amplitude comparison in the frequency domain plays a significant role. Its technique and parameter are called ultrasonic nonlinear technique and nonlinearity. A certain portion of nonlinearity comes from the equipment system, while the other portion of nonlinearity comes from the material. The former is system nonlinearity, while the latter is material nonlinearity. System nonlinearity interferes with interpretation, because its source is not from the material. In this study, in order to minimize system effects, a mixing technique is implemented. To use the large area inspection ability of the guided wave, the main research issue in this paper is focused on the guided wave mixing technique. Moreover, several bulk wave mixing theory equations become good concepts for guided wave mixing theoretical study, and the conventional nonlinear technique and guided wave mixing experimental results are compared in this study to confirm the reliability. This technique can play an important role in quantitatively discriminating fine damage by minimizing the nonlinearity of the equipment system.

APA, Harvard, Vancouver, ISO, and other styles

6

DURFEE III, C. G., A. RUNDQUIST, S. BACKUS, Z. CHANG, C. HERNE, H. C. KAPTEYN, and M. M. MURNANE. "GUIDED-WAVE PHASE-MATCHING OF ULTRASHORT-PULSE LIGHT." Journal of Nonlinear Optical Physics & Materials 08, no. 02 (June 1999): 211–34. http://dx.doi.org/10.1142/s0218863599000151.

Full text

Abstract:

We review the use of hollow waveguides for frequency conversion of ultrafast laser pulses the ultraviolet and extreme ultraviolet. Phase-matching of these processes is reached through a balance of gas and waveguide dispersion. By mixing 400 nm with 800 nm light, ultrashort (8 fs) pulses are generated near 270 nm with high efficiency > 20%. Tuning of the longer-wavelength component in the mixing process allows tuning of the output from 215–308 nm. In the XUV, this guided-wave phase-matching has allowed an increase of conversion efficiency of high-order harmonic generation of 100–1000x over that obtained with a gas jet, in an experimentally-convenient geometry.

APA, Harvard, Vancouver, ISO, and other styles

7

Sottini, Stefano, Emilia Giorgetti, Alessandro Gignoli, Luca Palchetti, and Daniela Grando. "Guided-light two-wave-mixing on a spherical surface." Optics Communications 173, no. 1-6 (January 2000): 389–95. http://dx.doi.org/10.1016/s0030-4018(99)00602-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Lissenden, Cliff J., Yang Liu, Vamshi K. Chillara, Gloria Choi, and Hwanjeong Cho. "Nonlinear Guided Wave Mixing for Localized Material State Characterization." Physics Procedia 70 (2015): 668–71. http://dx.doi.org/10.1016/j.phpro.2015.08.074.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Stegeman, G. I., E. M. Wright, and C. T. Seaton. "Degenerate four‐wave mixing from a waveguide with guided wave pump beams." Journal of Applied Physics 64, no. 9 (November 1988): 4318–22. http://dx.doi.org/10.1063/1.341306.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Yeung, Carman, and Ching Tai Ng. "Nonlinear guided wave mixing in pipes for detection of material nonlinearity." Journal of Sound and Vibration 485 (October 2020): 115541. http://dx.doi.org/10.1016/j.jsv.2020.115541.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Li, Weibin, Yaru Xu, Ning Hu, and Mingxi Deng. "Impact damage detection in composites using a guided wave mixing technique." Measurement Science and Technology 31, no. 1 (October 18, 2019): 014001. http://dx.doi.org/10.1088/1361-6501/ab382e.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Ng, Ching Tai, Carman Yeung, Tingyuan Yin, Yuncheng He, and Liujie Chen. "Investigation of nonlinear torsional guided wave mixing in pipes buried in soil." Engineering Structures 273 (December 2022): 115089. http://dx.doi.org/10.1016/j.engstruct.2022.115089.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Hu, Xianwen, Tingyuan Yin, Hankai Zhu, Ching-Tai Ng, and Andrei Kotousov. "Structural health monitoring of partially immersed metallic plates using nonlinear guided wave mixing." Construction and Building Materials 346 (September 2022): 128381. http://dx.doi.org/10.1016/j.conbuildmat.2022.128381.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Giorgetti, E., G. Margheri, L. Palchetti, S. Sottini, and M. Mennig. "A guided-wave configuration for two-wave-mixing-based devices containing highly absorbing Au-doped sol-gels." Applied Physics B: Lasers and Optics 67, no. 5 (November 1, 1998): 587–91. http://dx.doi.org/10.1007/s003400050551.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

Zeng, Lunwu, Zhongliang Tang, Hua Li, Yanyan Zhao, Cunli Dai, and Runxia Song. "Experimental observation of heat wave cloak." Modern Physics Letters B 28, no. 12 (May 19, 2014): 1450098. http://dx.doi.org/10.1142/s0217984914500985.

Full text

Abstract:

According to the heat conduction theory and effective medium theory, we fabricated a six-layer cylinder heat diffusion cloak by mixing heat conduction materials. We measured the time-dependant heat wave at the iso-temperature lines and the heat flux lines with a self-made heat wave device. The experiment results show that the iso-temperature lines are parallel outside the outer circle, the heat fluxes are parallel and equal outside the outer circle, and the heat fluxes in the inner circle are much smaller than those outside the outer circle, namely, the heat fluxes are guided outside the cloaking region.

APA, Harvard, Vancouver, ISO, and other styles

16

Zheltikov, Aleksei. "Phase-matched four-wave mixing of guided and leaky modes in an optical fiber." Optics Letters 33, no. 8 (April 14, 2008): 839. http://dx.doi.org/10.1364/ol.33.000839.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Ihn, Yong Sup, Zaeill Kim, and Su-Yong Lee. "Optical Wave Guiding and Spectral Properties of Micro/Nanofibers Used for Quantum Sensing and Quantum Light Generation." Applied Sciences 10, no. 2 (January 20, 2020): 715. http://dx.doi.org/10.3390/app10020715.

Full text

Abstract:

Subwavelength optical micro/nanofibers have been widely used as basic building blocks in the field of quantum sensing and quantum light source by virtue of their properties which include pronounced evanescent field, large surface area, and small optical mode area. This paper presents theoretical studies on the propagation properties of the guided optical wave and the spectral properties of entangled photons from spontaneous four-wave mixing in micro/nanofibers. We first analyze numerically single-mode propagation, field distribution, fraction of power, and group-velocity-dispersions by solving Maxwell’s equations with boundary conditions in cylindrical coordinates. Then, optical wave guiding properties of micro/nanofibers are applied to estimate the spectral properties such as central wavelengths and bandwidths of the created photons via spontaneous four-wave mixing that can be tailored by controlling diameter and length of micro/nanofibers. This theoretical work provides useful guidelines to design micro/nanofiber-based quantum sensing and quantum light sources for quantum technologies.

APA, Harvard, Vancouver, ISO, and other styles

18

Zhu, Hankai, Ching Tai Ng, and Andrei Kotousov. "Frequency selection and time shifting for maximizing the performance of low-frequency guided wave mixing." NDT & E International 133 (January 2023): 102735. http://dx.doi.org/10.1016/j.ndteint.2022.102735.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Shan, Shengbo, Mostafa Hasanian, Hwanjeong Cho, Cliff J. Lissenden, and Li Cheng. "New nonlinear ultrasonic method for material characterization: Codirectional shear horizontal guided wave mixing in plate." Ultrasonics 96 (July 2019): 64–74. http://dx.doi.org/10.1016/j.ultras.2019.04.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

20

Cho, Hwanjeong, Mostafa Hasanian, Shengbo Shan, and Cliff J. Lissenden. "Nonlinear guided wave technique for localized damage detection in plates with surface-bonded sensors to receive Lamb waves generated by shear-horizontal wave mixing." NDT & E International 102 (March 2019): 35–46. http://dx.doi.org/10.1016/j.ndteint.2018.10.011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

De Leonardis, Francesco, Richard Soref, Martino De Carlo, and Vittorio M. N. Passaro. "On-Chip Group-IV Heisenberg-Limited Sagnac Interferometric Gyroscope at Room Temperature." Sensors 20, no. 12 (June 19, 2020): 3476. http://dx.doi.org/10.3390/s20123476.

Full text

Abstract:

A room-temperature strip-guided “manufacturable” Silicon-on-Insulator (SOI)/GeSn integrated-photonics quantum-gyroscope chip operating at 1550 nm is proposed and analysed. We demonstrate how the entangled photons generated in Si Spontaneous Four Wave Mixing (SFWM) can be used to improve the resolution of a Sagnac interferometric gyroscope. We propose different integrated architectures based on degenerate and non-degenerate SFWM. The chip comprises several beam splitters, two SFWM entangled photon sources, a pump filter, integrated Mach–Zehnder interferometric gyro, and an array of waveguide coupled GeSn/Ge/Si single-photon avalanche detectors. The laser pumped SWFM sources generate the signal-idler pairs, which, in turn, are used to measure the two-photon, four-photon, and higher order coincidences, resulting in an increasing of the gyro resolution by a factor of two and four, with respect to the classical approach.

APA, Harvard, Vancouver, ISO, and other styles

22

Yang, Joseph, Toshi Kubota, and Edward E. Zukoski. "A model for characterization of a vortex pair formed by shock passage over a light-gas inhomogeneity." Journal of Fluid Mechanics 258 (January 10, 1994): 217–44. http://dx.doi.org/10.1017/s0022112094003307.

Full text

Abstract:

This work investigates the two-dimensional flow of a shock wave over a circular light-gas inhomogeneity in a channel with finite width. The pressure gradient from the shock wave interacts with the density gradient at the edge of the inhomogeneity to deposit vorticity around the perimeter, and the structure rolls up into a pair of counter-rotating vortices. The aim of this study is to develop an understanding of the scaling laws for the flow field produced by this interaction at times long after the passage of the shock across the inhomogeneity. Numerical simulations are performed for various initial conditions and the results are used to guide the development of relatively simple algebraic models that characterize the dynamics of the vortex pair, and that allow extrapolation of the numerical results to conditions more nearly of interest in practical situations. The models are not derived directly from the equations of motion but depend on these equations and on intuition guided by the numerical results. Agreement between simulations and models is generally good except for a vortex-spacing model which is less satisfactory.A practical application of this shock-induced vortical flow is rapid and efficient mixing of fuel and oxidizer in a SCRAMJET combustion chamber. One possible injector design uses the interaction of an oblique shock wave with a jet of light fuel to generate vorticity which stirs and mixes the two fluids and lifts the burning jet away from the combustor wall. Marble proposed an analogy between this three-dimensional steady flow and the two-dimensional unsteady problem of the present investigation. Comparison is made between closely corresponding three-dimensional steady and two-dimensional unsteady flows, and a mathematical description of Marble's analogy is proposed.

APA, Harvard, Vancouver, ISO, and other styles

23

Petcher, P. A., and S. Dixon. "Mode mixing in shear horizontal ultrasonic guided waves." Nondestructive Testing and Evaluation 32, no. 2 (July 22, 2016): 113–32. http://dx.doi.org/10.1080/10589759.2016.1184268.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Blanloeuil, P., L. R. F. Rose, M. Veidt, and C. H. Wang. "Nonlinear mixing of non-collinear guided waves at a contact interface." Ultrasonics 110 (February 2021): 106222. http://dx.doi.org/10.1016/j.ultras.2020.106222.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Guo, Quanbing, Zhenwei Ou, Jibo Tang, Jing Zhang, Fengya Lu, Ke Wu, Douguo Zhang, Shunping Zhang, and Hongxing Xu. "Efficient Frequency Mixing of Guided Surface Waves by Atomically Thin Nonlinear Crystals." Nano Letters 20, no. 11 (October 14, 2020): 7956–63. http://dx.doi.org/10.1021/acs.nanolett.0c02736.

Full text

APA, Harvard, Vancouver, ISO, and other styles

26

Guo, Qi-Zhi, Yi-Chao Meng, Chao-Ying Zhao, and Wei-Han Tan. "Analogy between the four-wave mixing in atom gas system and that in optical fiber and double micro-ring system." Canadian Journal of Physics 97, no. 2 (February 2019): 216–21. http://dx.doi.org/10.1139/cjp-2017-0535.

Full text

Abstract:

The correspondence relation between the parameters of optical four-wave mixing (FWM) in atom system and that of the optical fiber and double-ring system is found out theoretically. Based on this relation, the transmission spectra for two systems are calculated numerically and the obtained results are essentially the same. Finally, a scheme of generation of Stokes and anti-Stokes photon pairs in the wave-guide and double-ring system corresponding to FWM in atom system is proposed.

APA, Harvard, Vancouver, ISO, and other styles

27

Whitehead, N. J., W. P. Gillin, I. V. Bradley, B. L. Weiss, and P. Claxton. "Disorder-induced mixing of InGaAs/InP multiple quantum wells by phosphorus implantation for optical wave-guides." Semiconductor Science and Technology 5, no. 11 (November 1, 1990): 1146. http://dx.doi.org/10.1088/0268-1242/5/11/515.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Kara, Farid, Fadhéla Otmane, Samir Bellal, Amira Djenet Guerfi, and S. Triaa. "Elaboration and Characterization of Cu Based Nanocomposites for Electromagnetic Interferences Shielding." Defect and Diffusion Forum 412 (November 12, 2021): 177–84. http://dx.doi.org/10.4028/www.scientific.net/ddf.412.177.

Full text

Abstract:

An electromagnetic interferences (EMI) shielding is a material that attenuates radiated electromagnetic energy. Polymer nanocomposites is a class of materials that combine electrical, thermal, dielectric, magnetic and/ or mechanical properties, which are useful for the suppression of electromagnetic interferences. In this work, we looked over the effectiveness of the electromagnetic interferences shielding of polymer-based nanocomposites. These are thin samples of epoxy resin strengthened with nanostructured Cu powders. Nanostructured Cu powders were obtained by mechanical milling using the high-energy RETSCH PM400 ball mill (200 rpm). A powder sampling was conducted after 3h, 6h, 12h, 24h, 33h, 46h and 58h milling for characterization requirements. XRD analysis via the Williamson-Hall method shows that the mean crystallites size decreases from 151.6 nm (pure Cu phase) to 13.8 nm (58 h milling). Simultaneously, the lattice strain increases from 0.1% (pure Cu phase) to 0.59% (58 h milling). The elaboration of thin samples was performed by mixing a vol./3 fractions of nanostructured Cu powder, epoxy resin and hardener. Thin slabs of 1 mm thickness were moulded for use in a rectangular wave-guide. The EMI shielding experimental involved a two ports S parameters cell measurement made of R120 metallic wave-guides of rectangular section (19.05x9.525 mm2) and operational over the frequency band of 9.84 to 15 GHz associated to a network analyser. Obtained results show moderate EMI shielding effectiveness for the milled Cu-based slabs.

APA, Harvard, Vancouver, ISO, and other styles

29

Sudiana, I. Nyoman, Muhammad Zamrun Firihu, La Aba, La Ode Ngkoimani, Prima Endang Susilowati, Seitaro Mitsudo, Bambang Sunendar Purwasasmita, Komang Gde Suastika, Lina Lestari, and Haji Aripin. "Characterization of Silica Extracted from Rice Husk Ash Wastes Doped by Tin Dioxide for Wave Guide Material." Solid State Phenomena 266 (October 2017): 148–52. http://dx.doi.org/10.4028/www.scientific.net/ssp.266.148.

Full text

Abstract:

A series of experiments is made to produce silica, mixing with tin dioxide (SnO2), and characterizing for application of waveguide device. Silica xerogels (SX) are prepared from raw materials derived from rice husks ash (RHA), which abundant in South East Sulawesi. The synthesis conditions have been optimized to obtain the ash of rice husks with the maximum silica content. SnO2 are prepared from a commercial powder. The ceramic waveguide materials are produced by mixing SX and SnO2 with various composition. The mixtures are molded to form the rectangular shape of 20 mm, 40 mm, and 5 mm in size. The samples will be sintered at different level of temperatures (from 300°C to 1200°C) by using microwave heating system as well as electric furnace. The microstructural of sintered samples were characterized on the basis of the experimental data obtained using densification measurement method (Archimedes method), crystallization (X-ray diffraction, XRD), microstructure (Scanning electron microscope, SEM). Optical and related properties such as the functional groups, structure, and absoption were characterized by using FTIR, Infrared and Raman Spectroscopy and absorption (UVVis). The permittivity and permeability will be calculated from S-parameters determined by using Vector Network Analyzer (VNA). Characterization results are presented in this paper and the others are will be published in another separated papers. Furthermore, the relationship between properties with SnO2 content and sintering temperature is also studied.

APA, Harvard, Vancouver, ISO, and other styles

30

Sieverding, C. H., T. Arts, R. De´nos, and F. Martelli. "Investigation of the Flow Field Downstream of a Turbine Trailing Edge Cooled Nozzle Guide Vane." Journal of Turbomachinery 118, no. 2 (April 1, 1996): 291–300. http://dx.doi.org/10.1115/1.2836639.

Full text

Abstract:

A trailing edge cooled low aspect ratio transonic turbine guide vane is investigated in the VKI Compression Tube Cascade Facility at an outlet Mach number M2, is = 1.05 and a coolant flow rate m˙c/m˙g = 3 percent. The outlet flow field is surveyed by combined total-directional pressure probes and temperature probes. Special emphasis is put on the development of low blockage probes. Additional information is provided by oil flow visualizations and numerical flow visualizations with a three-dimensional Navier–Stokes code. The test results describe the strong differences in the axial evolution of the hub and tip endwall and secondary flows and demonstrate the self-similarity of the midspan wake profiles. According to the total pressure and temperature profiles, the wake mixing appears to be very fast in the near-wake but very slow in the far-wake region. The total pressure wake profile appears to be little affected by the coolant flow ejection.

APA, Harvard, Vancouver, ISO, and other styles

31

Aerts, C., K. Augustson, S. Mathis, M. G. Pedersen, J. S. G. Mombarg, V. Vanlaer, J. Van Beeck, and T. Van Reeth. "Rossby numbers and stiffness values inferred from gravity-mode asteroseismology of rotating F- and B-type dwarfs." Astronomy & Astrophysics 656 (December 2021): A121. http://dx.doi.org/10.1051/0004-6361/202142151.

Full text

Abstract:

Context. Multi-dimensional (magneto-)hydrodynamical simulations of physical processes in stellar interiors depend on a multitude of uncalibrated free parameters, which set the spatial and time scales of their computations. Aims. We aim to provide an asteroseismic calibration of the wave and convective Rossby numbers, and of the stiffness at the interface between the convective core and radiative envelope of intermediate-mass stars. We deduce these quantities for rotating dwarfs from the observed properties of their identified gravity and gravito-inertial modes. Methods. We relied on near-core rotation rates and asteroseismic models of 26 B- and 37 F-type dwarf pulsators derived from 4-year Kepler space photometry, high-resolution spectroscopy, and Gaia astrometry in the literature to deduce their convective and wave Rossby numbers. We computed the stiffness at the interface of the convective core and the radiative envelope from the inferred maximum buoyancy frequency at the interface and the convective turnover frequency in the core. We use those asteroseismically inferred quantities to make predictions of convective penetration levels, local flux levels of gravito-inertial waves triggered by the convective core, and of the cores’ potential rotational and magnetic states. Results. Our sample of 63 gravito-inertial mode pulsators covers near-core rotation rates from almost zero up to the critical rate. The frequencies of their identified modes lead to models with stiffness values between 102.69 and 103.60 for the B-type pulsators, while those of F-type stars cover the range from 103.47 to 104.52. The convective Rossby numbers derived from the maximum convective diffusion coefficient in the convective core, based on mixing length theory and a value of the mixing length coefficient relevant for these pulsators, vary between 10−2.3 and 10−0.8 for B-type stars and 10−3 and 10−1.5 for F-type stars. The 17 B-type dwarfs with an asteroseismic estimate of the penetration depth reveal it to be in good agreement with recent theory of convective penetration that takes rotation into account. Theoretical estimates based on the observationally inferred convective Rossby numbers and stiffness values lead to local stochastically-excited gravito-inertial wave fluxes which may exceed those predicted for non-rotating cores, in agreement with observations. Finally, the convective core of rapid rotators is expected to have cylindrical differential rotation causing a magnetic field of 20–400 kG for B-type stars and of 0.1–3 MG for F-type stars. Conclusions. Our results provide asteroseismic calibrations to guide realistic (magneto-)hydrodynamical simultations of rotating (magnetised) core convection in stellar interiors of dwarfs and future modelling of transport and mixing processes in their interiors.

APA, Harvard, Vancouver, ISO, and other styles

32

Niu, Xiaochuan, Liqiang Zhu, and Zujun Yu. "The Effects of Stress on Second Harmonics in Plate-Like Structures." Applied Sciences 10, no. 15 (July 26, 2020): 5124. http://dx.doi.org/10.3390/app10155124.

Full text

Abstract:

Cumulative second harmonic of ultrasonic guided waves is considered to have great application potential in evaluating internal stress of structures. One difficulty with the application is the diversity and complexity of modal response to the stress change in waveguide. At present, there is a lack of relevant theoretical studies and experimental results to guide the applications. In this article, a method is proposed to characterize the amplitude change of cumulative second harmonic mode in a plate under stress through calculating the amplitude coefficient, which can be acquired based on mode shape analysis. The steel plate is taken as an example to demonstrate the analysis method. Experimental studies are presented with results consistent with the theoretical predictions. The results of this study indicate that the amplitudes of different cumulative second harmonic modes may increase or decrease monotonically with the change of stress. Therefore, when the phenomenon of modes mixing occurs in the waveguide, it is necessary to analyze and predict the amplitude of selected cumulative second harmonic mode with the change of stress in advance; otherwise, wrong results may be obtained. The method and conclusions proposed in this paper can also be applicable to waveguide of arbitrary cross-section and have universality.

APA, Harvard, Vancouver, ISO, and other styles

33

Li, Y. S., and N. A. Cumpsty. "Mixing in Axial Flow Compressors: Part II—Measurements in a Single-Stage Compressor and a Duct." Journal of Turbomachinery 113, no. 2 (April 1, 1991): 166–72. http://dx.doi.org/10.1115/1.2929076.

Full text

Abstract:

This paper follows directly from Part I, which contains not only the description of the facilities and the results for the C106 four-stage compressor, but also the background, list of nomenclature, acknowledgments, and references. The discussion and conclusions for Parts I and II are given here. The single-stage compressor results show the significant effects of inlet guide vane (IGV) wakes on mixing across the stage in the so-called “free-stream” region; in the casing region tip clearance flow is shown to play an important role in mixing. Explanations for these results are given. Investigations were also carried out in a two-dimensional rectangular duct flow to reveal the mixing mechanism in the corner region similar to those formed by blade surfaces and endwalls in a compressor. Turbulent diffusion has been found to be the dominant mechanism in spanwise mixing; anisotropic inhomogeneous turbulent diffusion is mainly responsible for the nonuniform mixing in the corner region. The larger spread of tracer gas in the tangential direction than in the radial direction is mainly caused by the wake dispersion and relative flow motions within the blade wakes as well as secondary flow contributions in the end-wall regions.

APA, Harvard, Vancouver, ISO, and other styles

34

Gupta, V. K., R. A. Jangid, and Seema Yadav. "Dielectric studies and microwave emissivity of alkaline soil of Alwar with mixing of gypsum." Material Science Research India 7, no. 2 (February 8, 2010): 519–24. http://dx.doi.org/10.13005/msri/070227.

Full text

Abstract:

The real and imaginary parts of dielectric constant (ε' and ε") of alkaline soil of Alwar with mixing of gypsum (0.0% to 10.0%, gravimetrically) determined at 34.50C temperature and at a single microwave frequency 9.78 GHz by wave guide cell method. Mixture of soil and gypsum is prepared at various moistness of soil varying from 0.0% to 12.0%. The ε' and ε" of gypsum are also determined. It was observed that ε' and ε" increases as percentage concentration of gypsum in the soil increase. It was observed that the effect of gypsum mixing on dielectric properties is more significant at higher level of soil moisture content. Further, microwave emissivities are estimated from measured values of ε' and ε" for dry and wet mixture of, soil and gypsum at various observation angles (00-800) for horizontal polarization. It was observed that emissivity of soil decreases as the percentage concentration of gypsum in the soil increases.

APA, Harvard, Vancouver, ISO, and other styles

35

Shubert, V. Alvin, David Schmitz, Chris Medcraft, Anna Krin, David Patterson, John M. Doyle, and Melanie Schnell. "Rotational spectroscopy and three-wave mixing of 4-carvomenthenol: A technical guide to measuring chirality in the microwave regime." Journal of Chemical Physics 142, no. 21 (June 7, 2015): 214201. http://dx.doi.org/10.1063/1.4921833.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Elefante, Arianna, Stefano Dello Russo, Fabrizio Sgobba, Luigi Santamaria Amato, Deborah Katia Pallotti, Daniele Dequal, and Mario Siciliani de Cumis. "Recent Progress in Short and Mid-Infrared Single-Photon Generation: A Review." Optics 4, no. 1 (January 12, 2023): 13–38. http://dx.doi.org/10.3390/opt4010003.

Full text

Abstract:

The generation of single photons in the mid-infrared spectral region is attracting the interest of scientific and technological research, motivated by the potential improvements that many important and emerging applications, such as quantum sensing, metrology and communication, could benefit from. This review reports the progress in short and mid-infrared single photon generation, focusing on probabilistic sources based on the two non-linear processes of spontaneous parametric downconversion (SPDC) and four wave mixing (FWM). On one hand, numerical simulations of mid-infrared SPDC are described as a powerful tool to assist and guide the experimental realization, along with the implementation and engineering of novel non-linear materials. On the other hand, the advantages offered by FWM in silicon waveguides in terms of integration, miniaturization and manufacturability are presented, providing an optimal technology for integrated quantum applications.

APA, Harvard, Vancouver, ISO, and other styles

37

Boujo, E., M. Bauerheim, and N. Noiray. "Saturation of a turbulent mixing layer over a cavity: response to harmonic forcing around mean flows." Journal of Fluid Mechanics 853 (August 23, 2018): 386–418. http://dx.doi.org/10.1017/jfm.2018.568.

Full text

Abstract:

Turbulent mixing layers over cavities can couple with acoustic waves and lead to undesired oscillations. To understand the nonlinear aspects of this phenomenon, a turbulent mixing layer over a deep cavity is considered and its response to harmonic forcing is analysed with large-eddy simulations (LES) and linearised Navier–Stokes equations (LNSE). The Reynolds number is $Re=150\,000$. As a model of incoming acoustic perturbations, spatially uniform time-harmonic velocity forcing is applied at the cavity end, with amplitudes spanning the wide range 0.045–8.9 % of the main channel bulk velocity. Compressible LES provide reference nonlinear responses of the shear layer, and the associated mean flows. Linear responses are calculated with the incompressible LNSE around the LES mean flows; they predict well the amplification (both measured with kinetic energy and with a proxy for vortex sound production in the mixing layer) and capture the nonlinear saturation observed as the forcing amplitude increases and the mixing layer thickens. Perhaps surprisingly, LNSE calculations based on a monochromatic (single-frequency) assumption yield a good agreement even though higher harmonics and their nonlinear interaction (Reynolds stresses) are not negligible. However, it is found that the leading Reynolds stresses do not force the mixing layer efficiently, as shown by a comparison with the optimal volume forcing obtained from a resolvent analysis. Therefore they cannot fully benefit from the potential for amplification available in the flow. Finally, the sensitivity of the optimal harmonic forcing at the cavity end is computed with an adjoint method. The sensitivities to mean flow modification and to a localised feedback (structural sensitivity) both identify the upstream cavity corner as the region where a small-amplitude modification has the strongest effect. This can guide in a systematic way the design of strategies aiming at controlling the amplification and saturation mechanisms.

APA, Harvard, Vancouver, ISO, and other styles

38

Li, Weibin, Zifeng Lan, Ning Hu, and Mingxi Deng. "Modeling and simulation of backward combined harmonic generation induced by one-way mixing of longitudinal ultrasonic guided waves in a circular pipe." Ultrasonics 113 (May 2021): 106356. http://dx.doi.org/10.1016/j.ultras.2021.106356.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Yu, Meihong, Chen Wang, Lei Wang, and Hongxia Zhao. "Optimization Design and Performance Evaluation of R1234yf Ejectors for Ejector-Based Refrigeration Systems." Entropy 24, no. 11 (November 10, 2022): 1632. http://dx.doi.org/10.3390/e24111632.

Full text

Abstract:

With the increasingly serious energy and environmental problems, the R1234yf ejector refrigeration system (ERS) shows great development potential in the refrigeration industry due to its simplicity, low maintenance costs and environmentally friendly nature. However, poor ejector performance has always been the main bottleneck for system applications. In order to overcome this problem, this paper proposes a design method for R1234yf ejectors based on the gas dynamic method and optimizes the geometrical parameters including the area ratio (AR) and nozzle exit position (NXP) to improve its performance through the control variable optimization algorithms. Based on the validated simulation model, the results show that the entrainment ratio increases initially and then decreases with the increase in AR and NXP, respectively; the AR has a significant effect on the shock wave position in the mixing chamber and the NXP can directly influence the expansion state of motive fluid; the ejector performance increases by about 17% over the initial entrainment ratio by the control variable optimization algorithms. This work can guide the R1234yf ejector design and promote the development of the ERS with environmentally friendly working fluids.

APA, Harvard, Vancouver, ISO, and other styles

40

Otmane, Fadhéla, Salim Triaa, A. Maali, and B. Rekioua. "Synthesis and Characterization of Fe-Based Nanocomposites." Diffusion Foundations 22 (May 2019): 39–47. http://dx.doi.org/10.4028/www.scientific.net/df.22.39.

Full text

Abstract:

This study reports on the elaboration and characterization of bulk nanocomposites samples obtained by dispersion of metallic powders at the nanoscale as reinforcements in a polymer matrix. Elemental Fe powders were successfully nanostructured via high-energy ball milling. Structural characterization of the produced powders was conducted using X-Ray Diffraction (XRD) analysis and Scanning Electron Microscopy (SEM). The Halder-Wagner approach was adopted to determine the powder’s average grain size, internal strain, lattice parameters and the mixing factors. Structural parameters evolution and morphological changes according to milling progression are discussed. Bulk nanocomposites samples were shaped in a home moulder by dispersion of coarse Fe and nanostructured Fe powders in a continuous matrix of commercial epoxy resin. The obtained bulk samples match the metallic X-band wave-guide WR-90 dimensions used for electromagnetic characterization. The two-port Sij scattering parameters were measured via an Agilent 8791 ES network analyzer. The measured scattering parameters served to calculate the loss factor of samples and to extract the dielectric permittivity via the Nicholson-Ross-Weir conversion. Spectra evolution of the scattering parameters, the loss factor and the dielectric constant for epoxy resin with coarse Fe and nanostructured Fe reinforcements are commented.

APA, Harvard, Vancouver, ISO, and other styles

41

Rumpf, Raymond C., Javier J. Pazos, Jennefir L. Digaum, and Stephen M. Kuebler. "Spatially variant periodic structures in electromagnetics." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 373, no. 2049 (August 28, 2015): 20140359. http://dx.doi.org/10.1098/rsta.2014.0359.

Full text

Abstract:

Spatial transforms are a popular technique for designing periodic structures that are macroscopically inhomogeneous. The structures are often required to be anisotropic, provide a magnetic response, and to have extreme values for the constitutive parameters in Maxwell's equations. Metamaterials and photonic crystals are capable of providing these, although sometimes only approximately. The problem still remains about how to generate the geometry of the final lattice when it is functionally graded, or spatially varied. This paper describes a simple numerical technique to spatially vary any periodic structure while minimizing deformations to the unit cells that would weaken or destroy the electromagnetic properties. New developments in this algorithm are disclosed that increase efficiency, improve the quality of the lattices and provide the ability to design aplanatic metasurfaces. The ability to spatially vary a lattice in this manner enables new design paradigms that are not possible using spatial transforms, three of which are discussed here. First, spatially variant self-collimating photonic crystals are shown to flow unguided waves around very tight bends using ordinary materials with low refractive index. Second, multi-mode waveguides in spatially variant band gap materials are shown to guide waves around bends without mixing power between the modes. Third, spatially variant anisotropic materials are shown to sculpt the near-field around electric components. This can be used to improve electromagnetic compatibility between components in close proximity.

APA, Harvard, Vancouver, ISO, and other styles

42

Pojman, John A. "Mathematical modeling of frontal polymerization." Mathematical Modelling of Natural Phenomena 14, no. 6 (2019): 604. http://dx.doi.org/10.1051/mmnp/2019059.

Full text

Abstract:

Frontal polymerization is way to convert liquid resin into a solid material with a self-propagating reaction. The reaction spreads like a flame from the heat of the reaction that diffuses into neighboring regions, starting more reaction. The frontal velocity has been accurately modeled for free-radical polymerization systems. The dynamics of fronts have been studied theoretically and experimentally. If the viscosity of the initial medium is low, then fronts can become unstable due to buoyancy-driven convection. A fascinating aspect of frontal polymerization is that fronts often do not propagate as a plane waves but exhibit complex modes such as “spin modes” and chaos. The kinetics of the polymerization significantly affects the onset of these modes. Multifunctional acrylates exhibit more complex dynamics than monoacrylates. Using multifunctional acrylates and inorganic fillers, 3P LLC created “cure-on demand” systems that do not require mixing before use, have a long shelf life and can be hardened in seconds to minutes. We consider two commercial products using frontal polymerization. The first is a wood filler that can be applied to a damaged section of wood and hardened in a few seconds by the application of heat to the surface. The second product is QuickCure Clay (QCC). QCC has an unlimited working time during which it can be sculpted. QCC is then cured by heating part of the object to 100 °C, setting off the propagating curing front. The modeling of frontal polymerization helped guide the development of these products.

APA, Harvard, Vancouver, ISO, and other styles

43

Spalart, Philippe R. "On the flow field induced by a hovering rotor or a static jet." Journal of Fluid Mechanics 701 (May 10, 2012): 473–81. http://dx.doi.org/10.1017/jfm.2012.188.

Full text

Abstract:

AbstractThe flow in the far field of an isolated static momentum source is considered, taking into account the entrainment of fluid by the turbulent jet which develops far downstream irrespective of the type of device. The result is a simple analytical model for the irrotational region, which depends only on the thrust applied. This equation is implied by Stewart (J. Fluid Mech., vol. 1, 1956, pp. 593–606) for a jet. For a rotor, the model is radically different from the classical one derived from an actuator disk without turbulence or mixing in the wake, which led to a sink flow in the far field. The velocities decay like $1/ r$ rather than $1/ {r}^{2} $, where $r$ is the radius, and are everywhere directed in the direction opposite to the thrust, rather than pointing towards the origin. The momentum source drives a co-flow which converges towards the turbulent region, thus supplying the entrained fluid. This flow pattern supports the assumption that the fluid surrounding the turbulent region is irrotational, better than the sink-flow model would. The model depends only on one empirical constant, a measure of the entrainment in a fully developed jet, for which a range of values is determined from the experimental literature. If the rotor is climbing, the sink flow is recovered; however, the limit of that equation as the climb velocity tends to zero, leading to hover, is singular. For both jets and rotors, this model used in a boundary condition should eliminate extraneous parameters and reduce the computational cost of numerical simulations, and may guide the design of chambers used for experiments, following Ricou & Spalding (J. Fluid Mech., vol. 11, 1960, pp. 21–32).

APA, Harvard, Vancouver, ISO, and other styles

44

Lissenden, Cliff J., Anurup Guha, and Mostafa Hasanian. "Mutual Interaction of Guided Waves Having Mixed Polarity for Early Detection of Material Degradation." Journal of Nondestructive Evaluation, Diagnostics and Prognostics of Engineering Systems 5, no. 4 (March 18, 2022). http://dx.doi.org/10.1115/1.4053959.

Full text

Abstract:

Abstract Guided wave mixing leverages mutual wave interactions to provide sensitive diagnostics of material degradation in plates and pipes and an early warning upon which maintenance decisions can be based. In some cases, the material to be interrogated may be otherwise inaccessible for nondestructive evaluation. The distortion of the waveform in nonlinear ultrasonics is typically quite small, often making it difficult to distinguish from nonlinearities in the sensing system. Mutual wave interactions are preferred to wave self-interactions in this respect because they can be designed to occur away from frequencies corrupted by sensing system nonlinearity. Furthermore, primary waves that generate secondary waves having a different polarity also provide a means to separate the material nonlinearity from the sensing system nonlinearity. Finite element simulations of wave mixing using a hyperelastic material model are conducted as a precursor to laboratory experiments to establish realistic expectations. In one case, shear-horizontal waves are mixed with co-directional symmetric Lamb waves to generate backpropagating shear-horizontal waves at the difference frequency. In the second case, counterpropagating shear-horizontal waves mix to generate secondary standing waves at the cutoff frequency of the S1 Lamb wave mode. In both cases, the results indicate that the larger the wave mixing zone, the more measurable is the amplitude of the secondary waves. These results will be used to design experiments that demonstrate the utility of these novel wave interactions.

APA, Harvard, Vancouver, ISO, and other styles

45

Klieber, Christoph, and David Linton Johnson. "Nonlinear phasing and dephasing of three-wave mixing of acoustic guided waves." Physical Review E 88, no. 3 (September 30, 2013). http://dx.doi.org/10.1103/physreve.88.033204.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Agrawal, Yamnesh, Akhilendra S. Gangwar, and D. M. Joglekar. "Localization of a Breathing Delamination Using Nonlinear Lamb Wave Mixing." Journal of Nondestructive Evaluation, Diagnostics and Prognostics of Engineering Systems 5, no. 3 (April 8, 2022). http://dx.doi.org/10.1115/1.4054100.

Full text

Abstract:

Abstract A guided wave-based method for localization of breathing delamination is presented in this investigation. The proposed technique utilizes one-way mixing of a dual-frequency fundamental antisymmetric Lamb modes with judiciously selected central frequencies. The dual-frequency interrogation signal, upon interacting with a breathing delamination, leads to additional frequency sidebands in the frequency response spectrum, strength of which is quantified in terms of the combination tone index. The numerical predictions of these sidebands are validated using an in-house experimentation. It is further exposited that the combination tone index depends strongly on the extent of the temporal overlap that the two constituent wave envelopes have as they propagate through the breathing delamination. Accordingly, for a synchronous passage (with 100% temporal overlap), the combination tone index is maximum while it reduces with the decreasing temporal overlap. By utilizing the dispersive nature of the chosen Lamb mode, a relation is then developed correlating the temporal separation of the wave envelopes at the location of the actuator, the group speeds, and the distance between the actuator and the delamination. Based on these inferences, a technique for localizing a breathing delamination is proposed, which involves interrogating the component by systematically altering the temporal overlap in the input waveform and monitoring the combination tone index for its maxima. The efficacy of the localization technique (close to 90%) is demonstrated through an illustrative case analyzed numerically as well as experimentally.

APA, Harvard, Vancouver, ISO, and other styles

47

Panchadhyayee, Pradipta, and Bibhas Kumar Dutta. "Spatially structured multi-wave-mixing induced nonlinear absorption and gain in a semiconductor quantum well." Scientific Reports 12, no. 1 (December 26, 2022). http://dx.doi.org/10.1038/s41598-022-26140-y.

Full text

Abstract:

AbstractWe have studied two-dimensional absorption and gain spectrum in an asymmetric semiconductor triple-coupled-quantum-well (TCQW) nanostructure. Four subband transitions are coupled by using four coherent fields in a close-loop configuration to introduce cross-Kerr effect and four-wave-mixing (FWM) induced nonlinearity in achieving nonlinear absorption and gain profiles. Position-dependent absorption and gain are obtained by applying one, or two coherent fields in a variety of standing wave configurations including superposed field configuration in the standing-wave regime. In addition to the control parameters like Rabi frequency and detuning, the specialty of the model is to employ double-controlled spatial phase-coherence guided by the FWM-induced phase and the phases introduced by the standing wave formation. Our results highlight the high-precision electron localization in spatial domain. The evolution of spatially modulated gain without inversion may be a substitute for obtaining gain from a traditional quantum cascade laser. The importance of the present work is to find its application in designing electro-optic modulators in semiconductor nanostructures in near future.

APA, Harvard, Vancouver, ISO, and other styles

48

Konorov, S. O., E. E. Serebryannikov, D. A. Akimov, A. A. Ivanov, M. V. Alfimov, and A. M. Zheltikov. "Phase-matched four-wave mixing of sub-100-TW∕cm2femtosecond laser pulses in isolated air-guided modes of a hollow photonic-crystal fiber." Physical Review E 70, no. 6 (December 28, 2004). http://dx.doi.org/10.1103/physreve.70.066625.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Salamin, Yannick, Ileana-Cristina Benea-Chelmus, Yuriy Fedoryshyn, Wolfgang Heni, Delwin L. Elder, Larry R. Dalton, Jérôme Faist, and Juerg Leuthold. "Compact and ultra-efficient broadband plasmonic terahertz field detector." Nature Communications 10, no. 1 (December 2019). http://dx.doi.org/10.1038/s41467-019-13490-x.

Full text

Abstract:

AbstractTerahertz sources and detectors have enabled numerous new applications from medical to communications. Yet, most efficient terahertz detection schemes rely on complex free-space optics and typically require high-power lasers as local oscillators. Here, we demonstrate a fiber-coupled, monolithic plasmonic terahertz field detector on a silicon-photonics platform featuring a detection bandwidth of 2.5 THz with a 65 dB dynamical range. The terahertz wave is measured through its nonlinear mixing with an optical probe pulse with an average power of only 63 nW. The high efficiency of the scheme relies on the extreme confinement of the terahertz field to a small volume of 10−8(λTHz/2)3. Additionally, on-chip guided plasmonic probe beams sample the terahertz signal efficiently in this volume. The approach results in an extremely short interaction length of only 5 μm, which eliminates the need for phase matching and shows the highest conversion efficiency per unit length up to date.

APA, Harvard, Vancouver, ISO, and other styles

50

Lan, Zifeng, Weibin Li, Mingxi Deng, and Yoji Okabe. "Combined harmonic generation of feature guided waves mixing in a welded joint." Wave Motion, December 2022, 103103. http://dx.doi.org/10.1016/j.wavemoti.2022.103103.

Full text

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!