Protection against the Effects of the Asynchronous Operation of Synchronous Motors Based on the Principle of Comparison of the Machine Power Factor

This paper deals with the possibility of using the principle of comparison of the operational power factor for evaluation of the asynchronous operation of synchronous motors. This way of definition of the asynchronous operation is possible to use for motors protection and other protective systems of drives with synchronous motors

Long-range surface plasmons supported by the disordered nanowire metamaterials

Considering the losses of metal and semiconductor and by obtaining exact dispersion relations of the modes, we theoretically study the propagation characteristics of surface plasmons supported by disordered nanowire metamaterials. The metamaterials are composed of disordered nanowires made of metal or semiconductor embedded into the dielectric material. In the case of the semiconductor nanowires, it is possible to considerably improve the propagation characteristics of surface plasmons supported by the system, as compared to the metallic nanowires

Investigation of the Nanostructured Semiconductor Metamaterials

The presence of electromagnetic waves on two-dimensional interfaces has been extensively studied over the last several decades. Surface plasmonic polariton (SPP), which normally exists at the interface between a noble metal and a dielectric, is treated as the most widely investigated surface wave. SPPs have promoted new applications in many fields such as microelectronics, photovoltaics, etc. Recently, it has been shown that by nanostructuring the metal surface, it is possible to modify the dispersion of SPPs in a prescribed manner. Herein, we demonstrate the existence of a new kind of surface wave between two anisotropic meta-materials. In contrast to extensively studied surface waves such as SPPs and Dyakonov waves, the surface waves supported by the nanostructured semiconductor metamaterial cross the light line, and a substantial portion at lower frequencies lies above the free-space light line. Consequently, the proposed structure will interact with the material via leaky waves

Analysis of cantilever of commercial building

Diplomová práce se zabývá analýzou dodatečně předpjatého železobetonového nosníku, jež je součástí vyložené části konstrukce administrativního objektu. Předmětem analýzy je zhodnocení chování konstrukce v čase a stanovení vhodného způsobu výstavby. Součástí práce je dále návrh a posouzení železobetonové desky a nosníku.This diploma thesis is about analysis of post-tensioned cantilever beam, which is part of cantilever of commercial building. The main part of thesis is evaluation of behavior of building structure in time and determination of the most suitable staging. Next part of thesis is design and evaluation of reinforced slab and beam.

Concrete retaining wall

Tato bakalářská práce se zabývá návrhem a posouzením železobetonové úhlové opěrné stěny. Jsou zde rozebrány účinky zatížení od jednotlivých návrhových přístupů uvedených v normě ČSN EN 1997. Posouzení samotné konstrukce je provedeno dle normy ČSN EN 1992.This thesis is about design and assessment of angular retaining wall from reinforced concrete. There are analyzed effects of loads from each design approach listed in standard ČSN EN 1997. The retaining wall is designed according to the standard ČSN EN 1992.

A systematic insight into the surface plasmon polaritons guided by the graphene based heterostructures

Graphene paves the way for the outstanding applications as it is one-atom thick and possesses perfect tunability properties. The main goal of this work is to study mode patterns of surface waves propagating in the graphene-based structures in the far-infrared region. Herein, we study a broad variety of graphene structures starting with the simplest graphene/dielectric interface guiding conventional surface plasmon polaritons (SPPs) and ending up with more complicated cases allowing to have a deeper insight into the complexity of the mode patterns tunability features provided by graphene paving the way for the hybridized waves. Thus, the hybridized surface-phonon-plasmon-polaritons (SPPPs) guided by graphene/LiF/glass compounds are theoretically studied. By constructing a heterostructure comprising graphene and LiF one may benefit from the advantages of both, resulting in engineerable hybridized SPPPs propagating in both directions, i.e. either forwardly or backwardly. Moreover, we conclude with presentation of the metamaterial composed of graphene and LiF building blocks allowing for an enhanced degree of freedom

Metamaterial formalism approach for advancing the recognition of glioma areas in brain tissue biopsies

Early detection of a tumor makes it more probable that the patient will, finally, beat cancer and recover. The main goal of broadly defined cancer diagnostics is to determine whether a patient has a tumor, where it is located, and its histological type and severity. The major characteristic of the cancer affected tissue is the presence of the glioma cells in the sample. The current approach in diagnosis focuses mainly on microbiological, immunological, and pathological aspects rather than on the “metamaterial geometry” of the diseases. The determination of the effective properties of the biological tissue samples and treating them as disordered metamaterial media has become possible with the development of effective medium approximation techniques. Their advantage lies in their capability to treat the biological tissue samples as metamaterial structures, possessing the well-studied properties. Here, we present, for the first time to our knowledge, the studies on metamaterial properties of biological tissues to identify healthy and cancerous areas in the brain tissue. The results show that the metamaterial properties strongly differ depending on the tissue type, if it is healthy or unhealthy. The obtained effective permittivity values were dependent on various factors, like the amount of different cell types in the sample and their distribution. Based on these findings, the identification of the cancer affected areas based on their effective medium properties was performed. These results prove the metamaterial model capability in recognition of the cancer affected areas. The presented approach can have a significant impact on the development of methodological approaches toward precise identification of pathological tissues and would allow for more effective detection of cancer-related changes

Enhancing the properties of plasmonic nanowires

In this paper, we show the approach to enhance the optical properties of the plasmonic nanowires from the perspectives of both field enhancement and tunability. Two different cases have been suggested for the consideration: the first one uses hollow-core metamaterial interface, while the other involves metallic nanowire metamaterial interface. It has been outlined, that the use of nanowire metamaterial interface allows for stretching the frequency range of surface wave existence from 500 THz (600 nm) to approximately 1000 THz (300 nm). Moreover, the nanowire metamaterial interface demonstrates better field confinement