scholarly journals The role of normal polarization in far-field subwavelength imaging by a dielectric microsphere or microcylinder

2020 ◽  
Vol 22 (7) ◽  
pp. 075002
Author(s):  
R Heydarian ◽  
C R Simovski
Keyword(s):  
Far Field ◽  
Subwavelength Imaging

scholarly journals Incorporating cumulative environmental effects of finfish mariculture into Canadian environmental assessment

2021 ◽  
Author(s):  
Sarah Coldwell King
Keyword(s):  
Decision Support ◽  
New Brunswick ◽  
Field Component ◽  
Far Field ◽  
Traffic Light ◽  
Environmental Assessments ◽  
Potential Site ◽  
Acceptability Criteria ◽  
New Criteria

A Traffic Light Decision Support System (DSS) used in marine finfish federal environmental assessments was expanded to include regional and cumulative environmental impacts. A retrospective review of 23 existing mariculture farms in southwestern New Brunswick indicated whether cumulative interactions would have justified site approvals. Six new criteria were added to the far-field component and other existing criteria were amended. Scores of A, B+, B⁻, C and pre-emptive C were based on acceptability criteria. Calculations of cumulative ecosystem indices and potential site indices revealed site acceptability, and the index combinations suggested potential site approvals predicted using Hargrave's (2002) three-colour Traffic Light scheme. Before mitigation was considered, 19 of 23 sites failed the amended set of criteria and after considering mitigation, 8 sites failed. Combining the site and ecosystem indices yielded varying site acceptability scores. The role of mitigation and other factors in hindering sustainable siting was discussed

scholarly journals Effect of interfacial slippage on the near-tip fields of an interface crack between a soft elastomer and a rigid substrate

2014 ◽  
Vol 470 (2170) ◽  
pp. 20140497 ◽  
Author(s):  
T. H. Lengyel ◽  
Rong Long ◽  
P. Schiavone
Keyword(s):  
Interface Crack ◽  
Wedge Angle ◽  
The Body ◽  
Far Field ◽  
Cauchy Stress ◽  
Rigid Substrate ◽  
Interfacial Cracks ◽  
Friction Surfaces ◽  
Interfacial Slippage

We consider the role of interfacial slippage in the deformation and stress fields near the tip of a plane interface crack occurring between a compressible hyperelastic material and a rigid substrate. Specifically, we draw comparisons between the two limiting cases of ‘no-slip’ (infinitely high friction) and ‘frictionless’ (zero friction) surfaces by performing corresponding asymptotic analyses in the crack-tip region. Our results indicate that for the no-slip case, when the body is subjected to far-field loading, the crack deforms to a wedge-like shape consistent with experimental observations reported in the literature. Moreover, in this case, the wedge angle is shown to be directly related to ratios of various Cauchy stress components on the bonded surface in the near-tip region. Finite-element simulations reveal that the wedge angle also depends on material compressibility and the far-field loading conditions. By contrast, the analysis of the frictionless case reveals that the crack consistently opens into a smooth parabolic shape with a right wedge angle and near-tip stress field dominated by the normal stress at the surface. The results established here can be used as a basis for the understanding of the role of varying degrees of slippage on interfacial cracks.

Robust far-field subwavelength imaging of scatterers by an acoustic superlens

2019 ◽  
Vol 146 (6) ◽  
pp. 4131-4143
Author(s):  
Yongkang Dong ◽  
Gaokun Yu ◽  
Ning Wang
Keyword(s):  
Far Field ◽  
Subwavelength Imaging

Conclusions from an Nea Workshop: The Role of Phenomenological Sorption Modelling in Performance Assessment of RadioactiveWaste Disposal Systems

1983 ◽  
Vol 26 ◽  
Author(s):  
A.B. Muller ◽  
D. Langmuir ◽  
I. Neretnieks
Keyword(s):  
Performance Analysis ◽  
Performance Assessment ◽  
Systems Design ◽  
Sorption Process ◽  
Surface Ionization ◽  
Natural Environments ◽  
Far Field ◽  
Degree Of Confidence ◽  
Site Characterisation

ABSTRACTTo give due credit to the barrier of the far field geologic environment in many host media it is necessary to account for sorption processes. The ultimate impact of sorption modelling will be in helping to define the degree of confidence that may be placed on geochemical retardation occurring in this barrier. For those involved in site characterisation, systems' design, design implementation and regulation, this confidence is best derived from a combination of a fundamental phenomenological understanding of the sorption process with empirical observations of sorption in natural environments. Neither alone is adequate. By performing a few additional measurements during classical Ko experiments, the data necessary for the more fundamental models, such as that of double-layer or surface ionization and complexation, may also be provided. The basis of these models and their integration into broader performance analysis are outlined in the context of how this maximises confidence in the geologic barrier of critically concerned groups.

Far-field subwavelength imaging for ultrasonic elastic waves in a plate using an elastic hyperlens

2011 ◽  
Vol 98 (24) ◽  
pp. 241912 ◽  
Author(s):  
Hyung Jin Lee ◽  
Hoe Woong Kim ◽  
Yoon Young Kim
Keyword(s):  
Elastic Waves ◽  
Far Field ◽  
Subwavelength Imaging

scholarly journals The propagation of small amplitude long waves on the surface of superfluid helium

1984 ◽  
Vol 25 (3) ◽  
pp. 311-348 ◽  
Author(s):  
R. S. Johnson
Keyword(s):  
Superfluid Helium ◽  
Small Amplitude ◽  
Long Waves ◽  
The Other ◽  
Physical Parameters ◽  
Surface Boundary ◽  
Far Field ◽  
Third Sound ◽  
Surface Boundary Conditions

AbstractVarious problems related to the propagation of small amplitude long waves on the surface of superfluid helium (helium II), usually called third sound, are studied on the basis of the appropriate governing equations. The two-fluid continuum model due to Landau is considered, with the effects of healing and relaxation incorporated, and viscosity, heat conduction and compressibility terms retained. The helium vapour is treated as a classical (Newtonian) compressible gas and the exact jump conditions across the liquid/vapour interface are employed. These liquid, vapour and jump equations constitute the exact problem although, in an effort to reduce the complexity of the equations, a simplified set of ‘model’ surface boundaiy conditions is also introduced. This full set of equations is non-dimensionalised taking care that all physical parameters are defined using only the undisturbed depth of the layer as the appropriate length scale. The ratio depth/wave-lenght (δ) is then a separate parameter as is the wave amplitude/depth ratio (ɛ). The limit which corresponds to the wave under discussion is then ɛ, δ → 0 with all the other parameters fixed.A number of analyses are presented, four of which describe various aspects of the linearised theory and two examine the nature of the far-field nonlinear problem. Using the simplified surface boundary conditions we discuss in turn: the wave motion in the absence of healing: the rôle of a second wave speed leading to a wave hierarchy; and the effects of healing. The final linearised problem makes use of the full vapour model, but again the healing terms are ignored. This latter analysis suggests that if the upper boundary of the vapour is sufficiently close to the liquid surface then third sound is suppressed.The complexity of the equations, particularly when the nonlinear terms are to be examined, is such that the incompressible limit is now taken in the absence of both healing and relaxation. Imposing the physically realistic limiting process (ɛ, δ → 0) we show that the only equation valid in the far-field is the Burgers equation. However, we also demonstrate that allowing the other parameters to be functions of e (which is not physically realisable in practice) it is easy to derive, for example, the Korteweg-de Vries equation.

Role of 5-hydroxytryptamine in the modulation of acoustic brainstem (far-field) potentials

1977 ◽  
Vol 16 (6) ◽  
pp. 447-449 ◽  
Author(s):  
Vinod K. Bhargava ◽  
Charles M. McKean
Keyword(s):  
Far Field ◽  
Field Potentials
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