scholarly journals Propagation and scattering effects in temporal metastructures

2021 ◽  
Vol 2015 (1) ◽  
pp. 012120
Author(s):  
D. Ramaccia ◽  
A. Alù ◽  
A. Toscano ◽  
F. Bilotti
Keyword(s):  
New Media ◽  
Electromagnetic Scattering ◽  
Material Properties ◽  
Design Strategies ◽  
Multilayered Structures ◽  
Analysis And Design ◽  
Electromagnetic Devices ◽  
Scattering Effects ◽  
Scattering Response ◽  
Transmission And Reflection

Abstract Electromagnetic scattering typically occurs when a change in the material properties is perceived by the propagating wave, that inevitably splits into a reflected and refracted wave to maintain the continuity of the field components at the interface between the two media. However, such a scattering phenomenon occurs also when the entire media suddenly switches its properties to other values at a certain instant of time, realizing the so-called temporal interface. After a temporal interface, a couple of waves, one reflected and one transmitted, starts to propagate in the new media with the same wavelength but at a different frequency. Exploiting the analogies and differences between spatial and temporal interfaces, in this contribution we present the temporal counterparts of conventional electromagnetic devices based on dielectric slabs and a cascade of them, i.e., the multilayered structures. We discuss about the analysis and design strategies for synthetizing the desired scattering response in both transmission and reflection and present the possible families of devices based on multi-switched temporal metamaterials that can be conceived.

Analysis and design of thermo-mechanical interfaces

2012 ◽  
Vol 60 (2) ◽  
pp. 205-213
Author(s):  
K. Dems ◽  
Z. Mróz
Keyword(s):  
Optimality Conditions ◽  
Mechanical Loading ◽  
Material Properties ◽  
Structural Response ◽  
External Boundary ◽  
Mechanical Loads ◽  
Internal Interface ◽  
Analysis And Design ◽  
First Order ◽  
Mechanical Nature

Abstract. An elastic structure subjected to thermal and mechanical loading with prescribed external boundary and varying internal interface is considered. The different thermal and mechanical nature of this interface is discussed, since the interface form and its properties affect strongly the structural response. The first-order sensitivities of an arbitrary thermal and mechanical behavioral functional with respect to shape and material properties of the interface are derived using the direct or adjoint approaches. Next the relevant optimality conditions are formulated. Some examples illustrate the applicability of proposed approach to control the structural response due to applied thermal and mechanical loads.

Development of CEM in Relation to Subsurface Electromagnetic Scattering

2012 ◽  
Vol 588-589 ◽  
pp. 2166-2170
Author(s):  
Ajaz Amna ◽  
Jia Dong Xu ◽  
Abdul Mueed
Keyword(s):  
Design Process ◽  
Electromagnetic Scattering ◽  
Problem Area ◽  
Subsurface Scattering ◽  
Em Scattering ◽  
Scattering Problems ◽  
Analysis And Design ◽  
Modeling Analysis ◽  
Terrestrial Environments ◽  
Indispensable Tool

Computational Electromagnetic (CEM) techniques have become an indispensable tool in efficient EM modeling, analysis and design process. EM subsurface scattering is a broad field of research with varying degree of complexity. Due level of the obscurity involved in the subsurface scattering investigation, it is therefore considered imperative to explore this problem area of EM for better insight through CEM-based study and models. In this paper, frequency domain CEM techniques are studied which have been tested to provide solution for subsurface scattering problems in terrestrial environments. The development of CEM methods for comparatively more complex problems of scattering from embedded non-metallic inhomogeneity in lossy, rough and layered media remains the focus of this article. The objective here is to provide an overview of CEM development by selecting few examples from the wide area of subsurface EM scattering.

Design of Stealthy Devices Made of Metamaterials with Material Properties

2013 ◽  
Vol 661 ◽  
pp. 95-98 ◽  
Author(s):  
Ye Liu ◽  
Zhu Ying Li ◽  
Wang Zhou Zhang ◽  
Yu Hong Sun
Keyword(s):  
Material Properties ◽  
Coordinate Transformation ◽  
Plane Electromagnetic Wave ◽  
Electromagnetic Devices ◽  
Specific Distribution ◽  
Permittivity And Permeability ◽  
Permeability Distribution ◽  
Electromagnetic Characteristics ◽  
Forming Condition

Using the method of electromagnetic coordinate transformation, through determination of the relation of permittivity and permeability distribution in different spaces, the forming condition of electromagnetic stealthy cloak made of metamaterial is discussed. On the specific distribution of permittivity and permeability, finite element method is used to analyze the electromagnetic characteristics of stealthy cloak which is radiated by plane electromagnetic wave. And the cloak shows excellent stealthy characteristic in theory at certain frequency of the wave. The result shows that the artificial metamterials, which are not found in nature, have the ability of controlling the electromagnetic field and changing the transmission path of wave. Besides stealthy cloak, new electromagnetic devices such as transparent device and concentrator, which are made of metamaterials designed by the coordinate transformation, are preliminarily discussed. They all have excellent stealthy characteristics.

X-ray diffuse scattering effects from Coulomb-type defects in multilayered structures

2009 ◽  
Vol 206 (8) ◽  
pp. 1790-1794 ◽  
Author(s):  
S. I. Olikhovskii ◽  
V. B. Molodkin ◽  
E. S. Skakunova ◽  
E. N. Kislovskii ◽  
I. M. Fodchuk
Keyword(s):  
Diffuse Scattering ◽  
Multilayered Structures ◽  
X Ray ◽  
Scattering Effects ◽  
Coulomb Type

scholarly journals Seismic Analysis of Steel Structures with and Without Bracings in Different Seismic Zones

2019 ◽  
Vol 8 (10) ◽  
pp. 4491-4494
Keyword(s):  
Material Properties ◽  
Seismic Analysis ◽  
Steel Structures ◽  
Seismic Loads ◽  
Rolled Steel ◽  
Analysis And Design ◽  
Seismic Zones ◽  
Steel Sections ◽  
Design Software ◽  
Support Conditions

In the present study four G+5 steel structures were modeled without bracings and having X, V bracings and diagonal bracings with foundation depth of 2m support conditions are assumed to be pinned at the bottom or at the supports/footings, seismic loads are applied as per IS:1893-2002 The structures having length = 28.2 m, width = 17m and height = 20m. The structures modeled in STAAD.Pro“structural analysis and design software by considering various loads and load combinations by their relative occurrence are considered the material properties considered are” Fe250 rolled steel sections structures were considered in seismic zones 2, 3, 4 and 5 X type bracings systems are observed to better in high seismic zones.

scholarly journals Traversing physical barriers and activating social voids

2021 ◽  
Author(s):  
Sara Ruffolo
Keyword(s):  
Design Research ◽  
Design Strategies ◽  
Social Barriers ◽  
Analysis And Design ◽  
Visible Minorities ◽  
Community Ties ◽  
Physical Barriers ◽  
Psychological Influences ◽  
The Individual ◽  
The Relationship

The following body of work is a culmination of theoretical analysis and design research that emerges on the recognition that within Toronto’s priority neighbourhoods exists both physical and social barriers that weaken community ties and social resiliency. The physical barriers it refers to are the city’s infrastructure and natural geographic features that commonly divide such neighbourhoods and create mobility issues for those residing within. At the same time they fracture social connections. This thesis investigates environmental psychology to better understand the relationship between the physical environment and its effect of human behaviour so that architecture can be conceived of as designed environments that indirectly influence the mood and behaviours of those occupying the space. The outcome is a complex system of applied architectural strategies that respond to physical, social, and psychological influences regarding the individual and the built environment. Collectively, the design strategies aim to reduce physical barriers, activate social voids, and create environments that enhance social behaviour among socially hesitant individuals and the development of community ties. This becomes a larger internal issue as the majority of the population within priority neighbourhoods being new immigrants and visible minorities share mutual feelings of social isolation, segregation and discomfort

Synthetic bioresorbable poly-α-hydroxyesters as peripheral nerve guidance conduits; a review of material properties, design strategies and their efficacy to date

2019 ◽  
Vol 7 (12) ◽  
pp. 4912-4943 ◽  
Author(s):  
Patrick Duffy ◽  
Seán McMahon ◽  
Xi Wang ◽  
Shane Keaveney ◽  
Eoin D. O'Cearbhaill ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Material Properties ◽  
Peripheral Nerve Injuries ◽  
Design Strategies ◽  
Nerve Injuries

Implantable tubular devices known as nerve guidance conduits (NGCs) have drawn considerable interest as an alternative to autografting in the repair of peripheral nerve injuries.

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