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Innovation Strategy of DPMB Tram Vehicles
Šiler, Martin ; Chaloupecký, Tomáš (referee) ; Bartes, František (advisor)
The diploma thesis proposes new innovation strategy for The Brno Public Transport Authority (DPMB) tram vehicles. The thesis reviews different approaches to transport innovation strategy. Analyse current strategy in Transport Authority and finally is proposed original innovation strategy of DPMB tram vehicles. The proposal aims to serve as strategical document for the management and stakeholders in tramway fleet renewal.
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Visualization of cryogenic helium flow using of laser-induced-fluorescence
Drahotský, Jakub ; Šiler, Martin (referee) ; Urban, Pavel (advisor)
This work evaluates the laser induced fluorescence method (LIF) for the vizualization of the cryogenic helium flows for experimental study of the Rayleigh–Bénard convection at the Institute of Scientific Instruments (ISI) in Brno in the labs of Cryogenics and Superconductivity group. As the tracer particles, we considered the metastable molecules He2*, that are created by the ionization of helium with themfemtosecond laser pulse and then they are excited by the lasers with appropriate wavelengths for the invocation of the fluorescence. On the basis of the research study, I have evaluated the current laser equipment at the ISI as insufficient for the experiment realization. At the end of this work, there is a list of a laser technique and other devices which are necessary for the adaptation of the LIF method in the experiments at ISI.
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Multimode optical fiber based endoscopy
Jákl, Petr ; Tučková, Tereza ; Pikálek, Tomáš ; Stibůrek, Miroslav ; Ondráčková, Petra ; Cifuentes, Angel S. ; Šiler, Martin ; Uhlířová, Hana ; Traegaardh, Johanna ; Čižmár, Tomáš
Optical microscopy is a technique for microworld investigation using light waves scattered on particles in sample space. Its main disadvantage in the area of medicine, microbiology and neurology is its low penetration depth - it is very difficult to image structures deeper than approximately 1 mm inside tissue. Conventional endoscopes use refractive or GRIN lens with cross-section of several milimeters in diameter. Therefore, it is necessary to find less invasive probes to perform imaging in living organisms. Favourable alternative is to use multimode optical fiber probe with 100 micrometer diameter. This approach, however, requires advanced shaping of the wavefront in order to achieve diffraction limited imaging.
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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.
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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.
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Innovation Strategy of DPMB Tram Vehicles
Šiler, Martin ; Chaloupecký, Tomáš (referee) ; Bartes, František (advisor)
The diploma thesis proposes new innovation strategy for The Brno Public Transport Authority (DPMB) tram vehicles. The thesis reviews different approaches to transport innovation strategy. Analyse current strategy in Transport Authority and finally is proposed original innovation strategy of DPMB tram vehicles. The proposal aims to serve as strategical document for the management and stakeholders in tramway fleet renewal.
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Visualization of cryogenic helium flow using of laser-induced-fluorescence
Drahotský, Jakub ; Šiler, Martin (referee) ; Urban, Pavel (advisor)
This work evaluates the laser induced fluorescence method (LIF) for the vizualization of the cryogenic helium flows for experimental study of the Rayleigh–Bénard convection at the Institute of Scientific Instruments (ISI) in Brno in the labs of Cryogenics and Superconductivity group. As the tracer particles, we considered the metastable molecules He2*, that are created by the ionization of helium with themfemtosecond laser pulse and then they are excited by the lasers with appropriate wavelengths for the invocation of the fluorescence. On the basis of the research study, I have evaluated the current laser equipment at the ISI as insufficient for the experiment realization. At the end of this work, there is a list of a laser technique and other devices which are necessary for the adaptation of the LIF method in the experiments at ISI.
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Principal component analysis of Raman spectroscopy data for determination of biofilm forming bacteria and yeasts
Šiler, Martin ; Samek, Ota ; Bernatová, Silvie ; Mlynariková, K. ; Ježek, Jan ; Šerý, Mojmír ; Krzyžánek, Vladislav ; Hrubanová, Kamila ; Holá, M. ; Růžička, F. ; Zemánek, Pavel
Many microorganisms (e.g., bacteria, yeast, and algae) are known to form a multi-layered structure composed of cells and extracellular matrix on various types of surfaces. Such a formation is known as the biofilm. Special attention is now paid to bacterial biofilms that are formed on the surface of medical implants, surgical fixations, and artificial tissue/vascular\nreplacements. Cells contained within such a biofilm are well protected against antibiotics and phagocytosis and, thus, effectively resist antimicrobial attack.\nA method for in vitro identification of individual bacterial cells as well as yeast colonies is presented. Figure 1 shows an an example of the biofilm formed by Staphylococcus epidermidis bacteria and Candida parapsilosis yeasts known for forming biofilms. The\npresented method is based on analysis of spectral “Raman fingerprints” obtained from the single cell or whole colony, see figure 2(top). Here, Raman spectra might be taken from the biofilm-forming cells without the influence of an extracellular matrix or directly form the bacterial/yeast colony.
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Golden nanoparticle in optical tweezers: influence of shape and orientation on optical trapping
Šiler, Martin ; Brzobohatý, Oto ; Chvátal, Lukáš ; Karásek, Vítězslav ; Paták, Aleš ; Pokorná, Zuzana ; Mika, Filip ; Zemánek, Pavel
Noble metal nanoparticles (NPs) have attracted increased attention in recent years due to various applications of resonant collective oscillations of free electrons excited with light (plasmon resonance). In contrast to bulk metal materials, where this plasmon resonance frequency depends only on the free electron number density, the optical response of gold and silver NPs can be tuned over the visible and near-infrared spectral region by the size and shape of the NP. Precise and remote placement and orientation of NPs inside cells or tissue would provide another degree of control for these applications. A single focused laser beam – optical tweezers – represents the most frequently used arrangement which provides threedimensional (3D) contact-less manipulation with dielectric objects or living cells ranging in size from tens of nanometers to tens of micrometers. It was believed that larger metal NPs behave as tiny mirrors that are pushed by the light beam radiative force along the direction of beam propagation, without a chance to be confined. However, recently several groups have reported successful optical trapping of gold and silver particles as large as 250 nm. We\noffer an explanation based on the fact that metal nanoparticles naturally occur in various nonspherical\nshapes, and their optical properties differ significantly due to changes in localized plasmon excitation.
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