Influence of electric discharges on bearings of electric machina

Bearing currents are one of cause’s bearings faults. The character of a lubricator belongs to main factor influencing an inception of bearing currents. We have analyzed the electric character variety kind of lubricators; the influence of lubricators on a bearing current was analyzed too. Some results from the mentioned research are introduced within this paper

The Effect of Rhodamine-Derived Superparamagnetic Maghemite Nanoparticles on the Motility of Human Mesenchymal Stem Cells and Mouse Embryonic Fibroblast Cells

Nanoparticles have become popular in life sciences in the last few years. They have been produced in many variants and have recently been used in both biological experiments and in clinical applications. Due to concerns over nanomaterial risks, there has been a dramatic increase in investigations focused on safety research. The aim of this paper is to present the advanced testing of rhodamine-derived superparamagnetic maghemite nanoparticles (SAMN-R), which are used for their nontoxicity, biocompatibility, biodegradability, and magnetic properties. Recent results were expanded upon from the basic cytotoxic tests to evaluate cell proliferation and migration potential. Two cell types were used for the cell proliferation and tracking study: mouse embryonic fibroblast cells (3T3) and human mesenchymal stem cells (hMSCs). Advanced microscopic methods allowed for the precise quantification of the function of both cell types. This study has demonstrated that a dose of nanoparticles lower than 20 microg-cm -2 per area of the dish does not negatively affect the cells’ morphology, migration, cytoskeletal function, proliferation, potential for wound healing, and single-cell migration in comparison to standard CellTracker Green CMFDA (5-chloromethylfluorescein diacetate). A higher dose of nanoparticles could be a potential risk for cytoskeletal folding and detachment of the cells from the solid extracellular matrix

High-Resolution Quantitative Phase Imaging of Plasmonic Metasurfaces with Sensitivity down to a Single Nanoantenna

Optical metasurfaces have emerged as a new generation of building blocks for multifunctional optics. Design and realization of metasurface elements place everincreasing demands on accurate assessment of phase alterations introduced by complex nanoantenna arrays, a process referred to as quantitative phase imaging. Despite considerable effort, the widefield (nonscanning) phase imaging that would approach resolution limits of optical microscopy and indicate the response of a single nanoantenna still remains a challenge. Here, we report on a new strategy in incoherent holographic imaging of metasurfaces, in which unprecedented spatial resolution and light sensitivity are achieved by taking full advantage of the polarization selective control of light through the geometric (PancharatnamBerry) phase. The measurement is carried out in an inherently stable common-path setup composed of a standard optical microscope and an add-on imaging module. Phase information is acquired from the mutual coherence function attainable in records created in broadband spatially incoherent light by the self-interference of scattered and leakage light coming from the metasurface. In calibration measurements, the phase was mapped with the precision and spatial background noise better than 0.01 and 0.05 rad, respectively. The imaging excels at the high spatial resolution that was demonstrated experimentally by the precise amplitude and phase restoration of vortex metalenses and a metasurface grating with 833 lines/mm. Thanks to superior light sensitivity of the method, we demonstrated for the first time to our knowledge the widefield measurement of the phase altered by a single nanoantenna while maintaining the precision well below 0.15 rad

Friction and lubrication of fascia

Diplomová práce byla součástí projektu „Regenerace a lubrikace fascií hyaluronanem“ společnosti Contipro a.s., jehož hlavním cílem je vývoj injekčního léčebného přípravku. Přibývá počet pacientů trpící tzv. bolestí myofasciálního původu v dolní části zad. Příčinou bolesti je zvýšená viskozita kyseliny hyaluronové, která je produkována mezi vrstvami fascií. Pokud je viskozita nízká, tak nedochází k ovlivňování vrstev fascií a součinitel tření je nízký. Úkolem přípravku je zlepšit klouzavý pohyb fascií a ulevit pacientovi od bolesti. Hlavní složkou léčebného přípravku je kyselina hyaluronová. Součástí projektu byla reologická a tribologická analýza vzorků kyseliny hyaluronové. Pro analýzu součinitele tření byl vytvořen tribologický model fascií v konfiguraci pin-on-plate. Na základě použitých modelů fascií byla zjištěna závislost mezi součinitelem tření a viskozitou u nativních roztoků kyseliny hyaluronové. U modelů a reálných fascií se zjistilo, že nativní roztok (Bonharen) dosahoval lepších třecích vlastností nežli roztoky derivátů kyseliny hyaluronové. Tyto analýzy přispěly nejen k vývoji léčebného přípravku, ale i pro vznik dalších studií, které by se chtěly zabývat biotribologií fascií.The diploma thesis was part of the project "Regeneration and lubrication of fascia with hyaluronan" of the company Contipro a.s., whose main goal is the development of an injectable medicinal product. The number of patients suffering from so-called myofascial lower back pain is increasing. The cause of the pain is increased hyaluronic acid, which is produced between the layers of the fascia. If the viscosity is low, the fascia layers are not affected and the coefficient of friction is low. The purpose of the product is to improve the sliding movement of the fascia and relieve patients of pain. The main component of the medicine is hyaluronic acid. The project included rheological and tribological analysis of hyaluronic acid samples. A tribological model of fascia in a pin-on-plate configuration was created for the analysis of the coefficient of friction. Based on the fascia models used, the dependence between the coefficient of friction and viscosity of native hyaluronic acid solutions was found. For models and real fascias, the native solution (Bonharen) was found to have better friction properties than hyaluronic acid derivatives. These analyzes have contributed not only to the development of the drug, but also to the emergence of other studies that would like to address the biotribology of fascia.