Počet nalezených dokumentů: 979
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Nanopatterning of Silicon Nitride Membranes
Matějka, Milan; Krátký, Stanislav; Řiháček, Tomáš; Kolařík, Vladimír; Chlumská, Jana; Urbánek, Michal
2017 - anglický
Membranes are typically created by a thin silicon nitride (SIN) layer deposited on a silicon wafer. Both, top and bottom side of the wafer is covered by a thin layer of the silicon nitride. The principle of silicon nitride membranes preparation is based on the wet anisotropic etching of the bottom side of the silicon wafer with crystallographic orientation (100). While the basic procedure for the preparation of such membranes is well known, the nano patterning of thin membranes presents quite important challenges. This is partially due to the mechanical stress which is typically presented within such membranes. The resolution requirements of the\nmembrane patterning have gradually increased. Advanced lithographic techniques and etching procedures had to be developed. This paper summarizes theoretical aspects, technological issues and achieved results. The application potential of silicon nitride membranes as a base for multifunctional micro system (MMS) is also\ndiscussed. Klíčová slova: e-beam writer; silicon nitride membranes; nano patterning; anisotropic etching Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Nanopatterning of Silicon Nitride Membranes

Membranes are typically created by a thin silicon nitride (SIN) layer deposited on a silicon wafer. Both, top and bottom side of the wafer is covered by a thin layer of the silicon nitride. The ...

Matějka, Milan; Krátký, Stanislav; Řiháček, Tomáš; Kolařík, Vladimír; Chlumská, Jana; Urbánek, Michal
Ústav přístrojové techniky, 2017

Effect of gold coating on emissivity and absorptivity of Ti-6Al-4V alloy
Frolec, Jiří; Králík, Tomáš; Musilová, Věra; Urban, Pavel
2017 - anglický
The article provides experimental analysis of total hemispherical emissivity and absorptivity of Ti-6Al-4V alloy before and after deposition of 1-2 .pí.m gold layer. We measured their dependences on the temperature of thermal radiation (varying from 20 K to 320 K) and confronted these results with mechanically polished copper, i.e. with material known for extremely low emissivity and absorptivity. Galvanic deposition of pure gold resulted in significant lowering of original emissivity of Ti-6Al-4V bare surfaces from 15.8 percent to 3.4 percent at 300 K and from 4.1 percent to 1.1 percent at 20 K. Our findings about thermal-radiative properties have practical relevance for an improvement of a low temperature part of an ultra-high vacuum scanning probe microscope\n(UHV-SPM) designed by our group and could also be useful for other applications and low temperature systems. Klíčová slova: cryogenics; gold films; heat transfer; thermal radiation Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Effect of gold coating on emissivity and absorptivity of Ti-6Al-4V alloy

The article provides experimental analysis of total hemispherical emissivity and absorptivity of Ti-6Al-4V alloy before and after deposition of 1-2 .pí.m gold layer. We measured their dependences on ...

Frolec, Jiří; Králík, Tomáš; Musilová, Věra; Urban, Pavel
Ústav přístrojové techniky, 2017

Role of the superconductivity in radiative heat transfer
Králík, Tomáš; Musilová, Věra; Srnka, Aleš; Fořt, Tomáš; Frolec, Jiří
2017 - anglický
The absorption and emission of thermal radiation by metals is related to their electrical properties that are influenced by impurities, defects and temperature. We show by some examples of measurements on common metals how different can be the thermal radiative properties. When the heat is transferred across a microscopic vacuum gap in the near field regime, it is possible to achieve a step-like change of the heat\ntransfer based on a superconducting transition. An interesting feature of this effect is the nonlinear thermal conductivity effecting a change of the sign of the differential thermal conductivity across the vacuum gap. Klíčová slova: thermal radiation; near field; superconductivity Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Role of the superconductivity in radiative heat transfer

The absorption and emission of thermal radiation by metals is related to their electrical properties that are influenced by impurities, defects and temperature. We show by some examples of ...

Králík, Tomáš; Musilová, Věra; Srnka, Aleš; Fořt, Tomáš; Frolec, Jiří
Ústav přístrojové techniky, 2017

Vliv aktuní dávky a chronického podání olanzapinu na funkční změny mozku u potkana
Dražanová, Eva; Rudá-Kučerová, J.; Krátká, Lucie; Horská, K.; Kotolová, H.; Štark, T.; Babinská, Z.; Micale, V.; Starčuk jr., Zenon
2017 - český
Olanzapin patří do skupiny atypických antipsychotik a běžně se používá při terapii schizofrenie. Zaměřili jsme se na změny perfuze mozkové tkáně u zdravých a MAM upravených zvířat. Detekovali jsme významně nižší prokrvení mozkové kůry při akutních a chronických olanzapinem léčených zvířat. Olanzapine belongs to the first choice drug in treatment of schizophrenia. We focused on blood perfusion changes inducted by acute and chronic application of olanzapine in healthy animals and MAM altered animals. We detectet significant lower perfusion of cerebral cortex in acute and chronic olanzapine treated animals. We susspect that it could be due to altered neurotransmiter regulation caused by olanzapine. Klíčová slova: olanzapine; ASL; MAM Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Vliv aktuní dávky a chronického podání olanzapinu na funkční změny mozku u potkana

Olanzapin patří do skupiny atypických antipsychotik a běžně se používá při terapii schizofrenie. Zaměřili jsme se na změny perfuze mozkové tkáně u zdravých a MAM upravených zvířat. Detekovali jsme ...

Dražanová, Eva; Rudá-Kučerová, J.; Krátká, Lucie; Horská, K.; Kotolová, H.; Štark, T.; Babinská, Z.; Micale, V.; Starčuk jr., Zenon
Ústav přístrojové techniky, 2017

Parameter Optimization of Multi-Level Diffraction Gratings
Matějka, Milan; Kolařík, Vladimír; Horáček, Miroslav; Král, Stanislav
2017 - anglický
Originally, the e-beam lithography (EBL) is a technique for creating high-resolution black and white masks for the optical lithography. Multi-level relief structures can be also prepared using EBL patterning. Their preparation is based on the image patterning with a gradient of exposure doses. Large-area multi-level structures can be effectively prepared using the electron beam pattern generator with a variable shaped beam. We present several writing strategies. Basically, the main writing strategy uses one stamp (i.e. one elementary exposure of the shaped electron beam) per one elementary area with the same exposure dose. This simple approach is fast and flexible, however it does not guarantee optimal results. The main problem is an imperfection of the stamps (size, shape, and homogeneity). Advanced algorithms are based on multiple\nexposure of the same elementary area, the total local exposure dose is a sum of several different elementary exposures (stamps). Using these algorithms, a smoother surface of the structure can be achieved. On the other hand, the writing speed is considerably decreased. Tradeoff between the achieved parameters and the writing speed is discussed for selected set of writing strategy algorithms. Klíčová slova: e-beam pattern generator; variable shaped beam; grayscale lithography; multi-level grating Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Parameter Optimization of Multi-Level Diffraction Gratings

Originally, the e-beam lithography (EBL) is a technique for creating high-resolution black and white masks for the optical lithography. Multi-level relief structures can be also prepared using EBL ...

Matějka, Milan; Kolařík, Vladimír; Horáček, Miroslav; Král, Stanislav
Ústav přístrojové techniky, 2017

Nežádoucí metabolické účinky aripiprazolu v poly I:C modelu schizofrenie u potkana
Horská, K.; Rudá-Kučerová, J.; Dražanová, Eva; Pistovčáková, J.; Karpíšek, M.; Kotolová, H.; Demlová, R.; Kašpárek, T.
2017 - anglický
The aim of this study was to evaluate metabolic phenotype of poly I:C rat model and asses metabolic effects of chronic aripiprazole treatment with regard to complex neuroendocrine regulations of energy homeostasis. Altered lipid profile in poly I:C model was observed. Leptin and GLP-1 serum levels were significantly reduced, while ghrelin level was elevated. Our data indicate that dysregulation of adipose tissue endocrine function and gastrointestinal hormones is implicated in metabolic adverse effects of antipsychotics. Klíčová slova: metabolic syndrome; aripiprazole; rat; poly I:C animal model Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Nežádoucí metabolické účinky aripiprazolu v poly I:C modelu schizofrenie u potkana

The aim of this study was to evaluate metabolic phenotype of poly I:C rat model and asses metabolic effects of chronic aripiprazole treatment with regard to complex neuroendocrine regulations of ...

Horská, K.; Rudá-Kučerová, J.; Dražanová, Eva; Pistovčáková, J.; Karpíšek, M.; Kotolová, H.; Demlová, R.; Kašpárek, T.
Ústav přístrojové techniky, 2017

Phyllotactic Model Linking Nano and Macro World
Horáček, Miroslav; Meluzín, Petr; Krátký, Stanislav; Urbánek, Michal; Bok, Jan; Kolařík, Vladimír
2017 - anglický
Recently, the arrangement of diffraction primitives according to a phyllotactic model was presented. This arrangement was used to benchmarking purposes of the e-beam writer nano patterning. The phyllotactic arrangement has several interesting properties. One of them is related with the coherence between the nanoor microscopic domain of individual optical primitives and the properties of visually perceived images crated by these structures in the macro domain. This paper presents theoretical analysis of the phyllotactic arrangement in the referred context. Different approaches enabling the creation of diffractive optically variable images are proposed. The practical part of the presented work deals with the nano patterning of such structures using two different types of the e-beam pattern generators. One of them is a system with a variable shaped beam of electrons, while the other one is a system with a Gaussian-shaped beam. E-beam writing strategies and the use of inherent spiral patterns for exposure ordering and partitioning are also discussed. Klíčová slova: nano patterning; spiral grating structure; phyllotactic pattern; e-beam writer Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Phyllotactic Model Linking Nano and Macro World

Recently, the arrangement of diffraction primitives according to a phyllotactic model was presented. This arrangement was used to benchmarking purposes of the e-beam writer nano patterning. The ...

Horáček, Miroslav; Meluzín, Petr; Krátký, Stanislav; Urbánek, Michal; Bok, Jan; Kolařík, Vladimír
Ústav přístrojové techniky, 2017

Effect of thermal radiation on low temperature measurement for various types of temperature sensor installations
Urban, Pavel; Hanzelka, Pavel; Králík, Tomáš; Vlček, Ivan; Srnka, Aleš
2017 - anglický
We investigated an effect of thermal radiation (300 K) on precision of low temperature measurement of a sample holder (or sample) in an UHV SEM/SPM microscope working at range down to 20 K for various ways of temperature sensor mounting. We designed a special copper casing for installation of Lake Shore\ntemperature sensors (CernoxTM and Si diodes) encapsulated in SD packages. The sensor body is attached direct to the casing using indium solder. The current leads pertaining to the sensor are thermally anchored but electrically insulated from the casing. Quality of sensors installation in the casing was tested for various ways of mounting on a cooled plate. Insufficient thermal anchoring of electrical wires and thermal shielding were imitated. Comparative measurement was also performed with sensors in SD package mounted without\ncasing. The experiments proved that our special design of temperature sensors casing is adequate for intended application of temperature measurement of sample holder in UHV SEM/SPM microscope. In contrary, measurement precision of unprotected sensors was absolutely unsuitable. Klíčová slova: low temperature; temperature sensor; thermal radiation Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Effect of thermal radiation on low temperature measurement for various types of temperature sensor installations

We investigated an effect of thermal radiation (300 K) on precision of low temperature measurement of a sample holder (or sample) in an UHV SEM/SPM microscope working at range down to 20 K for various ...

Urban, Pavel; Hanzelka, Pavel; Králík, Tomáš; Vlček, Ivan; Srnka, Aleš
Ústav přístrojové techniky, 2017

Structural Colors of Self-Similar Nano Patterns
Meluzín, Petr; Horáček, Miroslav; Krátký, Stanislav; Kolařík, Vladimír
2017 - anglický
E-beam lithography is a flexible technology for various diffraction gratings origination. The e-beam patterning typically allows for the creation of optical diffraction gratings in the first diffraction order. However, the very high resolution enables also the patterning of structures providing the zero-order diffraction. Recently, we presented a work on the structural colors of metallic layers covering both regular-line structures and CGH (computer generated hologram) structures. This work presents a study dealing with zero-order diffraction structures with self-similar properties. The practical part of the work is focused on two aspects: design parameters and technological issues. Variations in design parameters include the tone of the structure (positive or negative),\nthe density of filling, the filling factor, and the depth of the structures. The achieved gamut of colors may by primarily extended by the proper selection of metal deposition technology and its parameters, and further by the proper selection of the metal and the thickness of its layer; these are the technological issues. Klíčová slova: e-beam writer; nano patterning; self similarity; diffraction grating Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Structural Colors of Self-Similar Nano Patterns

E-beam lithography is a flexible technology for various diffraction gratings origination. The e-beam patterning typically allows for the creation of optical diffraction gratings in the first ...

Meluzín, Petr; Horáček, Miroslav; Krátký, Stanislav; Kolařík, Vladimír
Ústav přístrojové techniky, 2017

Blaze Gratings with a Ribbed Back Slope
Krátký, Stanislav; Meluzín, Petr; Horáček, Miroslav; Kolařík, Vladimír; Matějka, Milan; Chlumská, Jana; Král, Stanislav
2017 - anglický
Binary relief phase-modulated gratings provide symmetrical diffraction of the incoming light beam. Asymmetrical gratings, e.g. asymmetrical triangular blazed gratings, are characteristic by an asymmetrical diffraction behavior, where one of the first diffraction orders is more important than the other one. Electron beam lithography is a suitable and flexible tool for patterning of such kind of gratings. High quality results can be readily obtained when the period of the grating is relatively large and the relief depth is relatively low, this is the case of gratings with a small blaze angle. As the blaze angle increases, the quality of result suffers from several patterning-related issues. One of the problems is a reflection of the incoming light beam from the back slope (anti-blaze facet) of the blaze grating. We propose a novel configuration, with a ribbed modulation of the back slope. This modulation is perpendicular to the direction of the grating grooves. This paper presents an analysis of the proposed blazed grating configuration. E-beam pattern generators were used to prepare a few\nsamples of blaze gratings with a ribbed back slope. One part of the experiment was performed with a Gaussianshaped beam and another one with the variable-shaped beam. Results of the experiment are presented.\nFinally, we discuss the optical performance of two blaze gratings with similar parameters, one of them is with the flat back slope and another one is with the ribbed back slope. Klíčová slova: nano patterning; blazed diffraction grating; Gaussian-type beam; variable-shaped beam; electron beam writer Plné texty jsou dostupné na jednotlivých ústavech Akademie věd ČR.
Blaze Gratings with a Ribbed Back Slope

Binary relief phase-modulated gratings provide symmetrical diffraction of the incoming light beam. Asymmetrical gratings, e.g. asymmetrical triangular blazed gratings, are characteristic by an ...

Krátký, Stanislav; Meluzín, Petr; Horáček, Miroslav; Kolařík, Vladimír; Matějka, Milan; Chlumská, Jana; Král, Stanislav
Ústav přístrojové techniky, 2017

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