Determination of the maximum bandwidth of a single-layer ferrite absorber of electromagnetic waves from the magnetic susceptibility spectrum

1987 ◽  
Vol 30 (11) ◽  
pp. 963-967
Author(s):  
A. S. Khlystov ◽  
A. M. Timoshenko
2015 ◽  
Vol 1117 ◽  
pp. 39-43
Author(s):  
I.A. Faniayeu ◽  
I.V. Semchenko ◽  
S.A. Khakhomov ◽  
Tatsiana Dziarzhauskaya

The electrically thin absorber of electromagnetic waves is under study. We proposed a new concept of the perfect absorber which consists from a single layer of the smooth double-turn helices. This allows one to design an absorber with unprecedentedly small thickness. Simple and smooth shape of the helices makes them more preferable from experimental point of view in comparison to other chiral particles. The absorber implies absence of a ground plane. High efficiency of the realized structure in the S band is demonstrated.


1991 ◽  
Vol 45 (2) ◽  
pp. 173-190 ◽  
Author(s):  
Maurizio Lontano ◽  
Nicolai Lunin

The properties of electromagnetic wave propagation in a uniformly densitymodulated plasma are studied, starting from a unidimensional scalar wave (Hill) equation for the wave electric field. Introduction of the formalism of the spatial propagator Q(z2, z1), from the point z1 to the point z2 allows reduction of the problem to determination of the propagator relevant to a single plasma layer that constitutes the entire periodic structure. The transmission coefficient of a single layer can be computed for any kind of density profile by means of the Magnus approximation, satisfying energy flux conservation at each order in the relevant expansion. The appearance of ‘forbidden zones’ in parameter space leads to the possibility that the incident electromagnetic wave can be partially or completely reflected if a sufficient number of periods are present. The explicit computation of the transmission coefficient for a series of n successive layers confirms this effect as the result of a ‘resonant’ interaction of the incident wave and the ‘periodicity’ of the medium.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Zaoli ◽  
Piero Mazzarisi ◽  
Fabrizio Lillo

AbstractBetweenness centrality quantifies the importance of a vertex for the information flow in a network. The standard betweenness centrality applies to static single-layer networks, but many real world networks are both dynamic and made of several layers. We propose a definition of betweenness centrality for temporal multiplexes. This definition accounts for the topological and temporal structure and for the duration of paths in the determination of the shortest paths. We propose an algorithm to compute the new metric using a mapping to a static graph. We apply the metric to a dataset of $$\sim 20$$ ∼ 20 k European flights and compare the results with those obtained with static or single-layer metrics. The differences in the airports rankings highlight the importance of considering the temporal multiplex structure and an appropriate distance metric.


2012 ◽  
Vol 2 (1) ◽  
Author(s):  
R. Angelova

AbstractThe paper presents an experimental procedure developed for determination of the pore size, shape and distribution in a single layer woven fabric, for the construction of a virtual model to be incorporated in a future CFD software package. The procedure is based on non-destructive observation and analysis of woven samples. 14 different samples of gray fabrics of 100 % cotton in plain and twill weaves are investigated. The results obtained allow the creation of reality more realistic virtual model of the woven structure, and theoretical investigation of its porosity and permeability through computer simulation.


Author(s):  
Vitaly Zholtikov ◽  
Vladimir Golovatinskii ◽  
Riadh Ouerghi ◽  
Rollin K Daniel

Abstract Background Camouflage of nasal dorsum, aesthetic augmentation and highlighting the dorsal aesthetic lines are essential elements in modern rhinoplasty. Numerous techniques have been utilized including deep temporal fascia, rectus abdominis fascia, and diced cartilage in fascia (DC-F). Despite their wide spread adoption, technical challenges remained, especially when utilized for aesthetic purposes. Objectives The paper details the use of fascia (F) and diced cartilage in fascia grafts (DC-F) for aesthetic dorsal refinement in primary and secondary cases. One of the main goals was to achieve ideal dorsal aesthetic dorsal lines rather than just volume augmentation. Methods We used grafts from the deep temporalis fascia (F) and rectus abdominis fascia (RF) in 4 configurations: 1) single layer, 2) double layer, 3) full length diced cartilage in fascia grafts (DC-F), and 4) partially filled – segmental DC-F grafts. Technical refinements included careful determination of dimensions and meticulously suturing to the dorsum at appropriately 10 points to prevent graft displacement. Results We report our experience: 146 clinical cases over 35 months from January 2017 to December 2019. The patients were divided for 4 groups depending on which type of graft was used. Conclusions Use of autogenous deep temporal fascia, rectus abdominis fascia, and diced cartilage in fascia (DC-F) to camouflage dorsal irregularities, to highlight dorsal aesthetic lines, and to aesthetically augment either the entire nasal dorsum or its individual parts. Optimization of cutting, stitching, filling the graft, careful fixation of these grafts on the nasal dorsum, significantly increases the predictability of these techniques and minimizes problems.


2020 ◽  
Vol 42 (6) ◽  
pp. 856-856
Author(s):  
Sehrish Qazi Sehrish Qazi ◽  
Huma Shaikh Huma Shaikh ◽  
Ayaz Ali Memon Ayaz Ali Memon ◽  
and Shahabuddin Memon and Shahabuddin Memon

Among all psychotropic alkaloids, nicotine is more addictive, carcinogenic and capable of causing many health problems. This work is based on the development of highly robust, cheap, reliable, selective and sensitive nicotine imprinted graphene oxide nanocomposite (ImpGO nanocomposite) based optical sensor for determination of nicotine in human plasma. The ImpGO nanocomposite has been thoroughly characterized using different techniques i.e. FT-IR, SEM, TEM, Raman, etc. These characterizations revealed that ImpGO nanocomposite is comprised of single layer of graphene oxide successfully modified with imprinted polymer. The synthesized material was utilized to selectively determine nicotine using UV-vis spectrophotometer in BR buffer of 0.1 M at pH 3 and diluted human plasma. The effect of parameters such as buffer concentration, pH, amount of nanocomposite, etc on determination of nicotine using ImpGO nanocomposite were studied thoroughly. Thus, a sensitive optical method was developed for determination of nicotine in human plasma with linear range of 22-370 pM along with LOD and LOQ of 7 pM and 22 pM, respectively. The selectivity of sensor was evaluated using homologues of nicotine such as nicotine amide, caffeine and cotinine. The results obtained from biological samples showed that developed optical sensor is efficient in complex matrices of real sample.


2015 ◽  
Vol 24 (3) ◽  
pp. 209-231 ◽  
Author(s):  
Hyeongseong Cho ◽  
Jong-Sun Kim ◽  
Kun-Ki Kim ◽  
Moo-Hwan Kang ◽  
Young Kwan Sohn ◽  
...  

A new measurement of the velocity of electromagnetic radiation is described. The result has been obtained, using micro-waves at a frequency of 24005 Mc/s ( λ = 1∙25 cm), with a form of interferometer which enables the free-space wave-length to be evaluated. Since the micro-wave frequency can also be ascertained, phase velocity is calculated from the product of frequency and wave-length. The most important aspect of the experiment is the application to the measured wave-length of a correction which arises from diffraction of the micro-wave beam. This correction is new to interferometry and is discussed in detail. The result obtained for the velocity, reduced to vacuum conditions, is c 0 = 299792∙6 ± 0∙7 km/s.


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