Národní úložiště šedé literatury Nalezeno 67 záznamů.  1 - 10dalšíkonec  přejít na záznam: Hledání trvalo 0.00 vteřin. 
Behaviour of Objects in Structured Light Fields and Low Pressures
Flajšmanová, Jana ; Čižmár, Tomáš (oponent) ; Marago, Onofrio (oponent) ; Zemánek, Pavel (vedoucí práce)
A deeper understanding of behaviour of optically trapped particles reveals underlying physical phenomena arising from the light-matter interaction. We present an explanation of the enhancement of the pulling force acting on optically bound particles in the structured optical field, so--called tractor beam. It is demonstrated that the motion of two optically bound objects in a tractor beam strongly depends on their mutual distance and spatial orientation, which adds an extra flexibility to our ability to control matter with light.\newline Subsequently, the thesis is focused on the optical levitation of a particle in a vacuum. We propose a novel methodology for a characterization of properties of a weakly nonlinear Duffing oscillator represented by an optically levitated nanoparticle. The method is based on averaging recorded trajectories with defined initial positions in the phase space of nanoparticle position and momentum and provides us with the oscillator parameters directly from the recorded motion. Our innovative approach is compared with the commonly used power--spectral--density fitting, and exploiting numerical simulations, we show its applicability even at lower pressures where the nonlinearity starts to play a~significant role.
Dětská léčebna Ostrov u Macochy
Zemánek, Pavel ; Vostrejž, Dušan (oponent) ; Odvárka, Antonín (vedoucí práce)
Architektonická studie se zabývá návrhem Dětské léčebny se speleoterapií v Ostrově u Macochy. Návrh pracuje s myšlenkou propojení s okolní přírodou, reaguje na svažitý terén a snaží se naplnit obsáhlý stavební program. Charakteristickým prvek je využití přírodního materiálu – dřeva v rámci obvodového pláště, který definuje architektonický výraz objektu. Je kladen důraz na obnovitelné zdroje energie.
SMV-2019-67: Vektorový režim
Jákl, Petr ; Zemánek, Pavel
Příprava experimentální aparatury a ovládacího software na fotopolymeraci nanostruktur ve vektorovém režimu. Nanostruktury jsou vytvářeny pomocí plynulého pohybu vzorku po zadané trajektorii se zapnutým laserovým svazkem.
Imaging via multimode optical fiber: recovery of a transmission matrix using internal references
Šiler, Martin ; Jákl, Petr ; Traegaardh, Johanna ; Ježek, Jan ; Uhlířová, Hana ; Tučková, Tereza ; Zemánek, Pavel ; Čižmár, Tomáš
Current research of life shows a great desire to study the mechanics of biological processes\ndirectly within the complexity of living organisms. However, majority of practical techniques\nused nowadays for tissue visualization can only reach depths of a few tens of micrometres as\nthe issue obscures deep imaging due to the random light scattering. Several imaging\ntechniques deal with this problems from different angels, such as optical coherence\ntomography, light sheet microscopy or structured light illumination A different and promising strategy to overcome the turbid nature of scattering tissues is to employ multimode optical fibers (MMF) as minimally invasive light guides or endoscopes to provide optical access inside. Although the theoretical description of light propagation through such fibers has been developed a long time ago it is frequently considered inadequate to describe real MMF. The inherent randomization of light propagating through MMFs is typically attributed to undetectable deviations from the ideal fiber structure. It is a commonly believed that this\nadditional chaos is unpredictable and that its influence grows with the length of the fiber.\nDespite this, light transport through MMFs remains deterministic and can be characterized by a transmission matrix (TM) which connects the intensity and phase patterns on the fiber input and output facets. Once the TM is known it can be used to create focus in any desired 3D\ncoordinates beyond the distal fiber facet, see figure 1, and perform e.g. fluorescence based\nlaser scanning microscopy or optical trapping.
Orbital motion from optical spin: the extraordinary momentum of circularly polarized light beams
Svak, Vojtěch ; Brzobohatý, Oto ; Šiler, Martin ; Jákl, Petr ; Zemánek, Pavel ; Simpson, Stephen Hugh
We provide a vivid demonstration of the mechanical effect of transverse spin momentum in an\noptical beam in free space. This component of the Poynting momentum was previously thought\nto be virtual, and unmeasurable. Here, its effect is revealed in the inertial motion of a probe\nparticle in a circularly polarized Gaussian trap, in vacuum. Transverse spin forces combine with\nthermal fluctuations to induce a striking range of non-equilibrium phenomena. With increasing\nbeam power we observe (i) growing departures from energy equipartition, (ii) the formation of\ncoherent, thermally excited orbits and, ultimately, (iii) the ejection of the particle from the trap.\nOur results complement and corroborate recent measurements of spin momentum in evanescent\nwaves, and extend them to a new geometry, in free space. In doing so, we exhibit fundamental,\ngeneric features of the mechanical interaction of circularly polarized light with matter. The work\nalso shows how observations of the under-damped motion of probe particles can provide detailed\ninformation about the nature and morphology of momentum flows in arbitrarily structured light\nfields as well as providing a test bed for elementary non-equilibrium statistical mechanics.
Optofluidic techniques for directed evolution of enzymes
Pilát, Zdeněk ; Ježek, Jan ; Samek, Ota ; Zemánek, Pavel ; Buryška, T. ; Damborský, J. ; Prokop, Z.
Enzymes are highly versatile and ubiquitous biological catalysts. They can greatly accelerate\nlarge variety of reactions, while ensuring appropriate catalytic activity and high selectivity.\nThese properties make enzymes attractive biocatalysts for a wide range of industrial and\nbiomedical applications. Over the last two decades, directed evolution of enzymes has\ntransformed the field of protein engineering.
Optical binding of polystyrene particles in tractor beam
Damková, Jana ; Chvátal, Lukáš ; Oulehla, Jindřich ; Ježek, Jan ; Brzobohatý, Oto ; Zemánek, Pavel
The motion of a particle illuminated by a laser beam is usually driven by the photon flow due\nto the radiation pressure and therefore for particle trapping, one has to employ gradient forces. But in a tractor beam, objects are illuminated by the uniform light intensity and even so they can be pulled against the beam propagation. There have been developed several techniques how to create such a tractor beam. In our case, the tractor beam is created by two identical Gaussian beams that interfere under the defined angle. It creates the\nstanding wave, where in the transversal plane the particle is trapped by means of the gradient\nforce, but in the total beam propagation direction, the particle manipulation is driven by the non-conservative force. It is remarkable that this force can for the specific combinations of\nparameters pull the micro-particle against the beam propagation. This kind of behavior is\nbecause of the particle scattering where the majority of the incident photons is scattered in the forward direction and, based on the principle of action and reaction, the transfer of\nmomentum leads to a backward movement of the object. The pushing and pulling force is\nsensitive to the polarization of the laser beam, its incident angle and the particle size so this\ntechnique can be used for example for sorting of objects of different sizes.
Polyfunkční dům Brno - Líšeň
Zemánek, Pavel ; Fišer, Jiří (oponent) ; Odvárka, Antonín (vedoucí práce) ; Pěnčík, Jan (vedoucí práce)
Předmětem bakalářské práce je vypracování projektové dokumentace polyfunkčního domu v Brně – Líšni. Objekt má 2 nadzemní podlaží a 2 podzemní podlaží. V prvním nadzemním podlaží se nachází pronajímatelné prostory (obchody). Ve druhém nadzemním a prvním podzemním podlaží se nachází pronajímatelné prostory (doktoři, administrativa). Ve druhém podzemním podlaží se nachází podzemní garáže. Vjezd do garáže je zajištěn venkovní rampou. Nosným systémem je železobetonový skelet. Objekt je založen na železobetonových patkách a pasech. Vnitřní schodiště je monolitické železobetonové. Střechy jsou navrženy jako ploché jednoplášťové.
SMV-2017-24: Zrychlení plošné fotopolymerace
Jákl, Petr ; Zemánek, Pavel
Rozšíření softwarového vybavení fotopolymerační aparatury o režim rychlejšího procesu.
Fluorescence a povrchem zesílená Ramanova spektroskopie v mikrofluidice pro monitorování enzymatických reakcí
Pilát, Zdeněk ; Šmatlo, Filip ; Ježek, Jan ; Krátký, Stanislav ; Zemánek, Pavel
Realizovali jsme dva různé systémy detekce koncentrace molekul v mikrofluidních systémech. První způsob využívá optická vlákna a detekuje intenzitu fluorescence, zatímco druhá metoda spočívá v užití povrchem zesílené Ramanovy spektroskopie (surface enhanced Raman spectroscopy, SERS).

Národní úložiště šedé literatury : Nalezeno 67 záznamů.   1 - 10dalšíkonec  přejít na záznam:
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