scholarly journals Partial Energy Transfer Model of Lamb Waves Scattering in Materially Isotropic Waveguides

2021 ◽  
Vol 11 (10) ◽  
pp. 4508
Author(s):  
Pavel Šofer ◽  
Michal Šofer ◽  
Marek Raček ◽  
Dawid Cekus ◽  
Paweł Kwiatoń
Keyword(s):  
Energy Transfer ◽  
Lamb Waves ◽  
Hybrid Approach ◽  
Wave Mode ◽  
Transfer Model ◽  
Material Interface ◽  
Modal Expansion ◽  
Scattering Coefficients ◽  
Expansion Technique ◽  
Partial Energy

The scattering phenomena of the fundamental antisymmetric Lamb wave mode with a horizontal notch enabling the partial energy transfer (PET) option is addressed in this paper. The PET functionality for a given waveguide is realized using the material interface. The energy scattering coefficients are identified using two methods, namely, a hybrid approach, which utilizes the finite element method (FEM) and the general orthogonality relation, and the semi-analytical approach, which combines the modal expansion technique with the orthogonal property of Lamb waves. Using the stress and displacement continuity conditions on the present (sub)waveguide interfaces, one can explicitly derive the global scattering matrix, which allows detailed analysis of the scattering process across the considered interfaces. Both methods are then adopted on a simple representation of a surface breaking crack in the form of a vertical notch, of which a certain section enables not only the reflection of the incident energy, but also its nonzero transfer. The presented results show very good conformity between both utilized approaches, thus leading to further development of an alternative technique.

Luminescence Linewidth Broadening and Nonradiative Energy Transfer Studies of Solid UO2+2-Datura

1992 ◽  
Vol 46 (9) ◽  
pp. 1376-1381 ◽  
Author(s):  
Huei-Yang D. Ke ◽  
Gary D. Rayson
Keyword(s):  
Energy Transfer ◽  
Emission Spectra ◽  
Blue Shift ◽  
Liquid Nitrogen Temperature ◽  
Peak Position ◽  
Nonradiative Energy Transfer ◽  
Wall Material ◽  
Transfer Model ◽  
Solution Ph ◽  
Linewidth Broadening

The emission spectra and fluorescence decay curves of solid UO2+2- Datura at liquid nitrogen temperature have been measured. The linewidth of the emission peaks of UO2+2 ions in UO2+2- Datura decreases with the UO2+2 concentration. This linewidth broadening phenomenon can be explained by the existence of resonance interactions between adjacent UO2+2- Datura species. The analysis of the emission peak position of the bound ions has been used to provide a measure of the electronic factors contributing to the interaction between the uranyl ion and phosphoryl and dicarboxyl moieties on the cell wall material. An observed blue shift of the uranyl fluorescence spectrum as a function of solution pH has been ascribed to a distortion of the normally linear O-U-O bond. An inter- and intra-molecular nonradiative energy transfer model has been successfully used to interpret the measured lifetime data of UO2+2- Datura.

Cooperative Pair Driven Quenching of Yb3+ Emission in Nanocrystalline ZrO2:Yb3+

2009 ◽  
Vol 5 ◽  
pp. 121-134 ◽  
Author(s):  
O. Meza ◽  
L.A. Diaz-Torres ◽  
P. Salas ◽  
E. De la Rosa ◽  
C. Ángeles-Chávez ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Crystalline Phase ◽  
Luminescence Quenching ◽  
Interaction Parameters ◽  
Transfer Model ◽  
Geometrical Construction ◽  
Transfer Processes ◽  
Nir Emission ◽  
Energy Transfer Model ◽  
Cooperative Energy

The concentration luminescence quenching of the NIR emission of Yb3+ in nanocrystalline ZrO2 is studied. It is found that the quenching is dominated by cooperative energy transfer processes from isolated Yb3+ ions to Yb-Yb pairs (Yb dimers). The Yb dimer concentration depends on the crystallite phase and size, which on time depends on Yb concentration. An extended energy transfer model was developed to predict the IR and cooperative visible fluorescence emissions by taking in to account the crystalline phase, the nanocrystals size, and the geometrical construction of Yb dimers. Our model succeeds to fit simultaneously both experimental VIS and NIR emissions, and the corresponding interaction parameters are reported.

scholarly journals Leaky Lamb Wave Radiation from a Waveguide Plate with Finite Width

2020 ◽  
Vol 10 (22) ◽  
pp. 8104
Author(s):  
Sang-Jin Park ◽  
Hoe-Woong Kim ◽  
Young-Sang Joo
Keyword(s):  
Lamb Wave ◽  
Lamb Waves ◽  
Wave Mode ◽  
Wave Radiation ◽  
Finite Width ◽  
Propagation Characteristics ◽  
Radiation Characteristics ◽  
Radiation Beam ◽  
Leaky Lamb Wave ◽  
Waveguide Sensor

In this paper, leaky Lamb wave radiation from a waveguide plate with finite width is investigated to gain a basic understanding of the radiation characteristics of the plate-type waveguide sensor. Although the leaky Lamb wave behavior has already been theoretically revealed, most studies have only dealt with two dimensional radiations of a single leaky Lamb wave mode in an infinitely wide plate, and the effect of the width modes (that are additionally formed by the lateral sides of the plate) on leaky Lamb wave radiation has not been fully addressed. This work aimed to explain the propagation behavior and characteristics of the Lamb waves induced by the existence of the width modes and to reveal their effects on leaky Lamb wave radiation for the performance improvement of the waveguide sensor. To investigate the effect of the width modes in a waveguide plate with finite width, propagation characteristics of the Lamb waves were analyzed by the semi-analytical finite element (SAFE) method. Then, the Lamb wave radiation was computationally modeled on the basis of the analyzed propagation characteristics and was also experimentally measured for comparison. From the modeled and measured results of the leaky radiation beam, it was found that the width modes could affect leaky Lamb wave radiation with the mode superposition and radiation characteristics were significantly changed depending on the wave phase of the superposed modes on the radiation surface.

scholarly journals Toward Multistate Pharmacy Practice: Enhancing Mobility and Portability of Pharmacist Licensure

2020 ◽  
pp. 106002802094525
Author(s):  
Alex J. Adams
Keyword(s):  
Lower Cost ◽  
Mutual Recognition ◽  
Hybrid Approach ◽  
Pharmacy Practice ◽  
Nursing Profession ◽  
Transfer Model ◽  
Recognition Model ◽  
Administrative Burden ◽  
Current State ◽  
Pharmacy Profession

Pharmacists are licensed in all 50 states. As society becomes increasingly mobile and interconnected, several models of cross-state pharmacy practice have emerged, straining the current state-based system of licensure. The nursing profession has provided a model for license portability that offers 3 primary advantages over the current pharmacist licensure model while still protecting safety: (1) faster speed, (2) lower cost, and (3) reduced administrative burden. A hybrid approach for the pharmacy profession that builds off of the expedited license transfer model and adds a mutual recognition model is ideal.

scholarly journals Supporting Students in Using Energy Ideas to Interpret Phenomena: The Role of an Energy Representation

2019 ◽  
Vol 18 (8) ◽  
pp. 1635-1654
Author(s):  
Marcus Kubsch ◽  
Jeffrey Nordine ◽  
David Fortus ◽  
Joseph Krajcik ◽  
Knut Neumann
Keyword(s):  
Energy Transfer ◽  
Qualitative Content Analysis ◽  
Transfer Model ◽  
School Students ◽  
Making Sense ◽  
8Th Grade ◽  
Quasi Experimental ◽  
Important Idea ◽  
Support Students

AbstractIn the sciences, energy is an important idea to get insight into phenomena, as energy can help to reveal hidden systems and processes. However, students commonly struggle to use energy ideas to interpret and explain phenomena. To support students in using energy ideas to interpret and explain phenomena, a range of different graphical representations are commonly used. However, there is little empirical research regarding whether and how these representations actually support students’ ability to use energy ideas. Building on common ways of representing energy transfer, we address this issue by exploring whether, and if so how, a specific representation called the energy transfer model (ETM) supports middle school students’ interpretation of phenomena using the idea of energy transfer. We conducted an interview study with N = 30 8th grade students in a quasi-experimental setting and used qualitative content analysis to investigate student answers. We found evidence that students who construct an ETM when making sense of phenomena consider the role of energy transfers between systems more comprehensively, i.e., they reason about hidden processes and systems to a larger extent than students who do not construct an ETM.

Suppressing Technique of the Antisymmetric Mode by the Superposition of Lamb Waves Generated by Two Laser Beams in a Thin Plate

2006 ◽  
Vol 321-323 ◽  
pp. 103-107
Author(s):  
Seung Seok Lee ◽  
Sang Whoe Dho
Keyword(s):  
Thin Plate ◽  
Opposite Direction ◽  
Lamb Wave ◽  
Lamb Waves ◽  
Wave Mode ◽  
Laser Beams ◽  
Symmetric Mode ◽  
Antisymmetric Mode

We present a suppressing technique of the antisymmetric mode by superposition of Lamb waves generated by two laser beams in a thin plate. Two Lamb waves of the same frequency propagating from the opposite direction simultaneously arrive at the point of measurement and are superposed to compose one Lamb wave. The amplitude of the superposed Lamb wave depends on the distance between two laser beams. The suppressing of antisymmetric Lamb wave mode is accomplished by selecting the distance between two beams which simultaneously satisfies the condition of the anti-node(maximum) for the symmetric mode and the minimum for the antisymmetric mode. By this method, the antisymmetric Lamb wave mode is suppressed to the degree of 1.4% of the amplitude measured at zero distance between two beams.

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