Characterization of Unsaturated Particulate Materials Using Elastic and Electromagnetic Waves

2004 ◽  
Vol 270-273 ◽  
pp. 1653-1658 ◽  
Author(s):  
Jun Su Choi ◽  
Ki Il Song ◽  
Gye Chun Cho ◽  
Seok Won Lee
Keyword(s):  
Electromagnetic Waves ◽  
Particulate Materials

scholarly journals SEARCHING AND MEASUREMENT OF FUNCTIONAL VOIDS BY MEANS OF GPR TOMOGRAPHY BY THE EXAMPLE OF TWO COLUMNS

2017 ◽  
Vol 13 (1) ◽  
pp. 94-109 ◽  
Author(s):  
Marina S. Sudakova ◽  
Eugeniya B. Terentieva ◽  
Alexey Yu. Kalashnikov
Keyword(s):  
Electromagnetic Waves ◽  
High Quality ◽  
Spherical Void ◽  
Engineering Structures ◽  
Measured Velocity ◽  
Inversion Result ◽  
Single Fold ◽  
Solid Part ◽  
Tomography Method

he present article focuses on GPR tomography method potential aimed at the search of functional voids and estimation of their sizes in engineering structures. The size of voids is assumed to be greater than the wavelength for usable frequency. Two examples of the GPR tomographic survey are examined: 1) a square con-crete pillar with granite coating and a square void in the center, 2) cylindrical granite column with functional spherical void which has iron walls. The following issues are considered in the article: the method, the structure of the acquired data, the picking of wanted waves, the analysis of tomographic inversion result, compared with the result of commonly used single-fold antenna geometry GPR. As a result of the research performed it was demonstrated that GPR tomography represents a good solution for the problem of detection, delineation and characterization of voids inside engineering structures. The velocity of electromagnetic waves propagated within the solid part of the column (concrete and granite) was accurately measured. The measured velocity can be con-sidered to the basis for physical properties estimation, for example humidity, voids ratio etc. The acquired quan-titative results are characterized by high quality and are more reliable compared to the results of single-fold GPR survey.

scholarly journals Sequential Collective Microanalysis (SCM) Applied on the Characterization of Atmospheric Carbonaceous Particulate Materials Collected in the Metropolitan Area of Monterrey, in México

2019 ◽  
Vol 25 (S2) ◽  
pp. 820-821
Author(s):  
Lucy T. González ◽  
F. E. Longoria Rodríguez ◽  
C. Leyva-Porras ◽  
I.A Estrada-Moreno ◽  
Yasmany Mancilla ◽  
...  
Keyword(s):  
Metropolitan Area ◽  
Particulate Materials

scholarly journals Antenna surface plasmon emission by inelastic tunneling

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Cheng Zhang ◽  
Jean-Paul Hugonin ◽  
Anne-Lise Coutrot ◽  
Christophe Sauvan ◽  
François Marquier ◽  
...  
Keyword(s):  
Surface Plasmons ◽  
Electromagnetic Waves ◽  
Electron Tunneling ◽  
Inelastic Electron ◽  
Antenna Surface ◽  
Surface Plasmons Polaritons ◽  
Inelastic Electron Tunneling ◽  
Electrical Source ◽  
Good Agreement

Abstract Surface plasmons polaritons are mixed electronic and electromagnetic waves. They have become a workhorse of nanophotonics because plasmonic modes can be confined in space at the nanometer scale and in time at the 10 fs scale. However, in practice, plasmonic modes are often excited using diffraction-limited beams. In order to take full advantage of their potential for sensing and information technology, it is necessary to develop a microscale ultrafast electrical source of surface plasmons. Here, we report the design, fabrication and characterization of nanoantennas to emit surface plasmons by inelastic electron tunneling. The antenna controls the emission spectrum, the emission polarization, and enhances the emission efficiency by more than three orders of magnitude. We introduce a theoretical model of the antenna in good agreement with the results.

A new method for acoustic characterization of particulate materials: preliminary results

2013 ◽  
Vol 56 (3) ◽  
pp. 135-156 ◽  
Author(s):  
V. S. Averbakh ◽  
A. V. Lebedev ◽  
S. A. Manakov ◽  
V. V. Bredikhin
Keyword(s):  
New Method ◽  
Particulate Materials ◽  
Preliminary Results ◽  
Acoustic Characterization

scholarly journals Coherent backscatter enhancement in bistatic Ku-/X-band radar observations of dry snow

2021 ◽  
Author(s):  
Marcel Stefko ◽  
Silvan Leinss ◽  
Othmar Frey ◽  
Irena Hajnsek
Keyword(s):  
Electromagnetic Waves ◽  
Bistatic Radar ◽  
Water Ice ◽  
Enhanced Backscattering ◽  
Radar Systems ◽  
X Band ◽  
Solar System Bodies ◽  
Coherent Backscatter ◽  
Ku Band

Abstract. The coherent backscatter opposition effect (CBOE) enhances the backscatter intensity of electromagnetic waves by up to a factor of two in a very narrow cone around the direct return direction when multiple scattering occurs in a weakly absorbing, disordered medium. So far, this effect has not been investigated in terrestrial snow in the microwave spectrum. It has also received little attention in scattering models. We present the first characterization of the CBOE in dry snow using ground-based and space-borne bistatic radar systems. For a seasonal snow pack in Ku-band (17.2 GHz), we found backscatter enhancement of 50–60 % (+1.8–2.0 dB) at zero bistatic angle and a peak half-width-at-half-maximum (HWHM) of 0.25°. In X-band (9.65 GHz), we found backscatter enhancement of at least 35 % (+1.3 dB) and an estimated HWHM of 0.12° in the accumulation areas of glaciers in the Jungfrau-Aletsch region, Switzerland. Sampling of the peak shape at different bistatic angles allows estimating the scattering and absorption mean free paths, ΛT and ΛA. In the VV polarization, we obtained ΛT = 0.4 ± 0.1 m and ΛA = 19 ± 12 m at Ku-band, and ΛT = 2.1 ± 0.4 m, ΛA = 21.8 ± 2.7 m at X-band. The HH polarization yielded similar results. The observed backscatter enhancement is thus significant enough to require consideration in backscatter models describing monostatic and bistatic radar experiments. Enhanced backscattering beyond the Earth, on the surface of solar system bodies, has been interpreted as being caused by the presence of water ice. In agreement with this interpretation, our results confirm the presence of the CBOE at X- and Ku-band frequencies in terrestrial snow.

Self-Assembly and Electrochemical Characterization of Ferrocene-based Molecular Diodes for Solar Rectenna Device

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3185-3194
Author(s):  
Vikas Jangid ◽  
Damien Brunel ◽  
Chrystelle Lebouin ◽  
Clement A. Reynaud ◽  
Esteban Sanchez-Adaime ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electromagnetic Waves ◽  
Terahertz Frequency ◽  
Self Assembled Monolayer ◽  
Molecular Diodes ◽  
Antenna Miniaturization ◽  
Molecular Diode ◽  
Dc Power ◽  
Absorption Of Light

AbstractBailey [1] proposed in 1972 that a nanoscale antenna coupled with a rectifier can harvest broad range electromagnetic radiation from visible to infrared. To incorporate this concept in practical systems, there were two main technological bottle necks that have to be overcome: antenna miniaturization and rectification in terahertz frequency. With current technology and equipment [2], we are proposing a third-generation rectenna-based solar cells composed of Ag nanocubes to harvest ambient visible and infrared electromagnetic waves coupled to ferrocene-based molecular diodes [3] capable of switching at terahertz frequency to convert this received energy into DC power. The function of these molecular diodes is two-fold: they rectify and provide an uniform nano-cavity between silver top electrode and gold bottom electrode. These nano-cavities are capable to support gap plasmon modes and absorption of light in both narrow and broad range, depending on the nanocube size and dispersion. A self-assembled monolayer (SAM) of ferrocene alkane-dithiol is deposited in this nano-cavity making it possible to form molecular sized nano-gaps well below the usual 3 nm, and this structure is robust and reproducible [4]. This SAM can be deposited directly or via a two-step click chemistry on the surface to have along with control over the orientation of the molecule. By tuning the orientation and position of the ferrocene moiety, the direction of rectification can be controlled [3]. Hence, the SAM does not only act as a rectifier but also provides mechanical support combining photonic and electrical properties. This paper focuses on studying the electrical and supramolecular structure of these molecular diode based SAMs.

Sign in / Sign up

Export Citation Format

Share Document