On the Classification of the Electric Field Spectroscopies:  Application to Raman Scattering

2000 ◽  
Vol 104 (18) ◽  
pp. 4167-4173 ◽  
Author(s):  
Jason C. Kirkwood ◽  
Darin J. Ulness ◽  
Albrecht
Keyword(s):  
Electric Field ◽  
Raman Scattering

scholarly journals Study on surface enhanced Raman scattering of Au and Au@Al2O3 spherical dimers based on 3D finite element method

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bao-xin Yan ◽  
Yan-ying Zhu ◽  
Yong Wei ◽  
Huan Pei
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Electric Field ◽  
Raman Scattering ◽  
Enhancement Factor ◽  
Field Enhancement ◽  
Electric Field Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

AbstractIn this paper, the surface enhanced Raman scattering (SERS) characteristics of Au and Au@Al2O3 nanoparticle dimers were calculated and analyzed by using finite element method (3D-FEM). Firstly, the electric field enhancement factors of Au nanoparticles at the dimer gap were optimized from three aspects: the incident angle of the incident light, the radius of nanoparticle and the distance of the dimer. Then, aluminum oxide is wrapped on the Au dimer. What is different from the previous simulation is that Al2O3 shell and Au core are regarded as a whole and the total radius of Au@Al2O3 dimer is controlled to remain unchanged. By comparing the distance of Au nucleus between Au and Au@Al2O3 dimer, it is found that the electric field enhancement factor of Au@Al2O3 dimer is much greater than that of Au dimer with the increase of Al2O3 thickness. The peak of electric field of Au@Al2O3 dimer moves towards the middle of the resonance peak of the two materials, and it is more concentrated than that of the Au dimer. The maximum electric field enhancement factor 583 is reached at the shell thickness of 1 nm. Our results provide a theoretical reference for the design of SERS substrate and the extension of the research scope.

scholarly journals Dielectrophoretic classification of fibres: principles and application to glass fibres suspended in air

2019 ◽  
Vol 213 ◽  
pp. 02053
Author(s):  
Frantisek Lizal ◽  
Milan Maly ◽  
Jakub Elcner ◽  
Arpad Farkas ◽  
Ondrej Pech ◽  
...  
Keyword(s):  
Electric Field ◽  
High Speed ◽  
Deposition Velocity ◽  
Uniform Electric Field ◽  
Electrical Mobility ◽  
Mobility Separation ◽  
Neutral Particles ◽  
Naturally Occurring ◽  
Two Parameters

Particles exposed to an electric field experience forces that influence their movement. This effect can be used for filtration of air, or for size classification of aerosols. The motion of charged particles in a non-uniform electric field is called electrophoresis. Two processes are involved in this phenomenon: 1) charging of particles and 2) electrical mobility separation. If fibres are exposed to electrophoresis, they are separated on the basis of two parameters: diameter and length. Regrettably, as naturally occurring fibres are polydisperse both in diameter and length, the electrophoresis is not very efficient in length classification. In contrast, dielectrophoresis is the motion of electrically neutral particles in a non-uniform electric field due to the induced charge separation within the particles. As deposition velocity of fibres induced by dielectrophoretic force strongly depends on length and only weakly on diameter, it can be used for efficient length classification. Principles of length classification of conducting and non-conducting fibres are presented together with design of a fibre classifier. Lastly, images of motion of fibres recorded by high-speed camera are depicted.

scholarly journals Concepts and Capabilities of In-House Built Nanosecond Pulsed Electric Field (nsPEF) Generators for Electroporation: State of Art

2020 ◽  
Vol 10 (12) ◽  
pp. 4244
Author(s):  
Paulius Butkus ◽  
Arūnas Murauskas ◽  
Sonata Tolvaišienė ◽  
Vitalij Novickij
Keyword(s):  
Electric Field ◽  
High Frequency ◽  
Pulsed Electric Field ◽  
Cell Permeabilization ◽  
Pulse Generators ◽  
Nanosecond Pulsed Electric Field ◽  
Forming Characteristics ◽  
State Of Art ◽  
Frequency Pulse

Electroporation is a pulsed electric field triggered phenomenon of cell permeabilization, which is extensively used in biomedical and biotechnological context. There is a growing scientific demand for high-voltage and/or high-frequency pulse generators for electropermeabilization of cells (electroporators). In the scope of this article we have reviewed the basic topologies of nanosecond pulsed electric field (nsPEF) generators for electroporation and the parametric capabilities of various in-house built devices, which were introduced in the last two decades. Classification of more than 60 various nsPEF generators was performed and pulse forming characteristics (pulse shape, voltage, duration and repetition frequency) were listed and compared. Lastly, the trends in the development of the electroporation technology were discussed.

scholarly journals Eigenvektoren und Intensitäten der Raman- Linien von Polaritonen in ein- und zweiachsigen Ionenkristallen / Eigenvectors and Intensities of Raman Lines of Polaritons in Uniaxial and Biaxial Ionic Crystals

1973 ◽  
Vol 28 (6) ◽  
pp. 1038-1039
Author(s):  
G. Borstel ◽  
L. Merten
Keyword(s):  
Electric Field ◽  
Raman Scattering ◽  
Cross Sections ◽  
Ionic Crystals ◽  
Explicit Formulas ◽  
Normal Coordinates ◽  
Scattering Cross ◽  
Scattering Cross Sections

Explicit formulas are derived for the eigenvectors of polaritons (quasi-normal coordinates and electric field). With these eigenvectors Raman scattering cross sections can be calculated directly.

scholarly journals Classification of Tropical Oceanic Precipitation using High-Altitude Aircraft Microwave and Electric Field Measurements

2006 ◽  
Vol 63 (1) ◽  
pp. 218-233 ◽  
Author(s):  
Robbie E. Hood ◽  
Daniel J. Cecil ◽  
Frank J. LaFontaine ◽  
Richard J. Blakeslee ◽  
Douglas M. Mach ◽  
...  
Keyword(s):  
Electric Field ◽  
High Altitude ◽  
Field Measurements ◽  
Analysis Tool ◽  
Western Atlantic ◽  
Lower Altitude ◽  
Field Information ◽  
Uninhabited Aerial Vehicles ◽  
Electric Field Measurements

Abstract During the 1998 and 2001 hurricane seasons of the western Atlantic Ocean and Gulf of Mexico, the Advanced Microwave Precipitation Radiometer (AMPR), the ER-2 Doppler (EDOP) radar, and the Lightning Instrument Package (LIP) were flown aboard the NASA ER-2 high-altitude aircraft as part of the Third Convection and Moisture Experiment (CAMEX-3) and the Fourth Convection and Moisture Experiment (CAMEX-4). Several hurricanes, tropical storms, and other precipitation systems were sampled during these experiments. An oceanic rainfall screening technique has been developed using AMPR passive microwave observations of these systems collected at frequencies of 10.7, 19.35, 37.1, and 85.5 GHz. This technique combines the information content of the four AMPR frequencies regarding the gross vertical structure of hydrometeors into an intuitive and easily executable precipitation mapping format. The results have been verified using vertical profiles of EDOP reflectivity and lower-altitude horizontal reflectivity scans collected by the NOAA WP-3D Orion radar. Matching the rainfall classification results with coincident electric field information collected by the LIP readily identifies convective rain regions within the precipitation fields. This technique shows promise as a real-time research and analysis tool for monitoring vertical updraft strength and convective intensity from airborne platforms such as remotely operated or uninhabited aerial vehicles. The technique is analyzed and discussed for a wide variety of precipitation types using the 26 August 1998 observations of Hurricane Bonnie near landfall.

Local Electric Field Enhancement of Neighboring Ag Nanoparticles in Surface Enhanced Raman Scattering

2013 ◽  
Vol 760-762 ◽  
pp. 801-805 ◽  
Author(s):  
Chao Yue Deng ◽  
Gu Ling Zhang ◽  
Bin Zou ◽  
Hong Long Shi ◽  
Yu Jie Liang ◽  
...  
Keyword(s):  
Electric Field ◽  
Raman Scattering ◽  
Electric Fields ◽  
Ag Nanoparticles ◽  
Surface Enhanced Raman Scattering ◽  
Ag Nps ◽  
Sers Enhancement ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering

We used a simple low-temperature hydrothermal approach to synthesize Ag nanoparticles (NPs) and demonstrated their efficiency as organic molecule detectors in surface enhanced Raman Scattering (SERS). Using finite difference time domain simulation, we described an investigation on the distribution of electric fields amplitude of the neighboring Ag NPs. The enhanced electric field is confined at the interparticle gaps and the enhancement factor can be further increased with reducing the spacing between the NPs. The theoretical simulation demonstrated good consistency with the experimental measurement results, which predicts an electric fields amplitude enhancement of 115 at the center of NPs gap and an electromagnetic SERS enhancement of 108. The evidence of clear correlations between SERS enhancement and morphology distribution offer a route to develop more effective SERS substrates.

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