The suppresion of mechanical stress impacts in fiber optic transmission systems

Práce se zabývá problematikou potlačení mechanických vlivů při přenosu optickým vláknem. V práci je proveden rozbor vlivů, které mají největší vliv na polarizaci v optickém vlákně. Jsou navrženy metody pro zachování polarizace v optickém vlákně. Teoreticky jsou analyzovány metody pro zachování stavu polarizace v optickém vlákně. Vybraná metoda je teoreticky analyzována a experimentálně realizována. Na základě získaných výsledků se tato metoda ukázala jako vhodná pro řešení tohoto problému.This bachelors project deals with the suppresion of mechanical stress impacts in fiber optic transmission systems. Factors that have major influence on the polarization state distortion in optical fiber are discussed. It has been propřed the utilization of orthoconjugate retroreflector (OKR) for the compensation of polarization state degeneration. The theoretical analysis of this method is performed. The OKR method has been experimentally verified in the fiber optic current sensor. On the basis of results which were obtained by experimental verification the experimental results show evidence konvenience of the designed method.

What Is the Effect of Long-Term Cutting versus Abandonment on the Vegetation and Chemical Properties in the Soil and the Herbage of a Mountain Hay Meadow (\u3cem\u3ePolygono-Trisetion\u3c/em\u3e)?

Polygono-Trisetion meadow communities are endangered in Europe. These meadows are common in the Alps, but in the past, such meadows were also common in the western alpine regions of Central Europe. The aim of our experiment was to find a suitable management regime for the maintenance of these Polygono-Trisetion grasslands and its effect on the vegetation and chemical properties of the soil and in the herbage

The Effect of Different Grazing Managements on Upland Grassland

A transformation process in the Czech economy led to a rapid decrease in livestock numbers in the Czech Republic and an enlarged area of grasslands at the beginning of 1990’s. The result was extensification of grassland management and also abandonment in marginal areas. The main purpose of this study was to reveal how different managements affect plant species diversity of previously abandoned grassland

Degradation mechanisms of lead-acid batteries

Tato práce se zabývá problematikou degradačních mechanismů olověných akumulátorů. K bližšímu pochopení jednotlivých vlivů způsobujících degradaci je proveden rozbor a fyzikální objasnění každého z degradačních mechanismů. V práci je popsána měřící metoda, pomocí které budou zkoumány jednotlivé projevy degradačních mechanismů. Na závěr práce jsou provedena měření, ve kterých je možno vysledovat projevy jednotlivých degradačních mechanismů v olověném akumulátoru odehrávajících se především na aktivním povrchu elektrod.This work deals with problems of degradation mechanisms of lead-acid batteries. For a better understanding of the diverse effects that cause the degradation are analyzed and the physical explanation of each of the degradation mechanisms. The paper describes the measuring method by which they examined the different manifestations of degradation mechanisms. At the conclusion of works are carried out measurements in which it is possible to trace the manifestations of the various degradation mechanisms in lead battery taking place mainly on the active surface electrodes.

REMEDIATION TECHNOLOGY OF CLOCHE REPLACEMENT FOR WW2 FORTIFICATION IN THE CZECH REPUBLIC

Nowadays many parts of the Czechoslovak border fortification built in 1935 – 1938 have been sold to the private owners who want to reconstruct it. One of the biggest problems while reconstructing these objects is missing cloches. The aim of this study is to find solution of this problem. Authors wanted to offer the owners (usually clubs of military history) authentic design of the cloche for low cost, high durability and full functionality of the cloche that enables installation of original weapons.A result of the work was a development of a technical solution of the cloche consisting of a replica of the upper part made of reinforced concrete in combination with lower part made of concrete. This unique technical solution was confirmed as an utility model CZ32920(U1). Remediation measure was approved by the team at the pillbox T-S 20 in Červený Kostelec in 2019

Modeling of the multichannel optical wireless link

Tato práce se zabývá problematikou vícekanálových bezkabelových spojů s vyšším dosahem určeným pro komunikaci ve volném atmosférickém prostředí. Je proveden rozbor šíření optického svazku atmosférickým prostředím a popsány různé vlivy, které působí na kvalitu přenášeného signálu. V práci je provedena simulace duálního optického spoje, kterou jsou zjištěny energetické bilance optických zdrojů pracujících na vlnových délkách v atmosférických oknech v oblasti 850 a 1550nm. Je také zkoumáno rozložení optické intenzity ve vysílací části. Na závěr práce jsou proveden měření, která ověřují správnost simulací a také použitých komponent bezdrátového spoje.This thesis deals with multi-channel wireless links with a higher range designated for free-space communications in an atmospheric media. Propagation of the optical beam in an atmosphere is analysed and various influences affecting the quality of the transmitted signal are described. The simulation is carried out for dual optical link. Link budget of individual paths working at the wavelengths in the atmospheric windows – 850 nm and 1550nm. It also examined optical intensity distribution of the transmitted beam. At the end of the work performed measurements and simulations verify the accuracy of the components used in wireless link.

Management of permanent grasslands in relation to agri-environmental measures:Questions and answers

This methodology simplified results from research project “Functional plant traits and their diversity as indicators of various permanent grassland management” for nature conservation authority. It is based on long term grassland experiments. There are important data for preparing of some agro-environmental provision in the practical part. This work summarises the results of long-term experiments with the different management treatments. It is intended especially for employers of administration of nature conservation, and also it can be used for students and pedagogues of secondary schools and universities concerning nature conservation

Regeneration of Nardus stricta subalpine grasslands in the Giant Mountains (Krkonoše)

The origin of Nardus stricta dominated subalpine grassland (Nardo-Caricion rigidae alliance) is a frequently discussed topic in the Giant Mountains (Karkonosze in the Czech Republic). Many researchers considered them, as secondary stands arisen after Pinus mugo removal and by consequent oligotrophization of original plant communities, caused by long-term rough grazing and hay making activities without manuring. On the contrary, they are recognized as natural due to inability of generative reproduction of N. stricta and the very slow vegetative spread there. The aim of this study was to find proofs for generative reproduction of mat grass in subalpine conditions of the Giant Mountains. We identified a Pinus mugo nursery with arable land abandoned in 1956 and compared its vegetation with that of the surrounding area. Dense and homogenous sward dominated by N. stricta developed during the succession on the old arable land for 48 years, and it is an indisputable proof of generative reproduction of N. stricta there. Synthesizing historical facts on human activities in the past and the results of our contemporary vegetation analysis, we conclude that the Nardo-Caricion rigidae grassland was capable to spread relatively quickly, when agricultural activities above the upper timber line were introduced