154 research outputs found

    Small digital oscilloscope

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    Náplní tohoto projektu je návrh a realizace digitálního paměťového osciloskopu, založeného na osobním počítači, a jeho ovládacího programu. Modul osciloskopu komunikuje s ovládacím programem, nainstalovaným na osobním počítači, pomocí USB sběrnice. Modul osciloskopu disponuje 2 analogovými a 22 digitálními vstupy.This project deals with a design and prototyping of personal computer-based digital storage oscilloscope and its control software. Oscilloscope module communicates with installed control software touch the Universal Serial Bus interface. Oscilloscope module contains 2 analog and 22 digital inputs.

    CNC milling machine driving interface

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    Tato diplomová práce se zabývá návrhem a stavbou portálové CNC frézky určené primárně pro obrábění součástí z lehkých kovů a jejich slitin. V tomto dokumentu je popsán výběr mechanických komponent, návrh rámu frézky a průběh její stavby, návrh a stavba USB interpolační jednotky a vytvořený ovládací software.This project deals with portal-type CNC milling machine design and construction. CNC milling machine should be able to machining light metals and alloys. This document contains description of mechanical components selection, machine frame design and building, design and construction of USB motion control unit and also contains control software description and user manual.

    Development of vascular substitues for low flow peripheral vascular reconstructions

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    SOUHRN Vývoj cévní náhrady pro nízké průtoky je aktuální otázkou. Model hledání vývoje náhrady optimálních vlastností, který vychází z myšlenky převzetí charakteristiky biologického modelu - veny safeny, a naprogramování těchto vlastností do modelu konstruované náhrady, je jedním z možných směrů vývoje. Představovaná náhrada, která je výsledkem práce autorského kolektivu doktoranda, se skládá ze tří částí - nevstřebatelného scaffoldu představujícího medii, a dvou vstřebatelných kolagenních vrstev - pseudointimy a pseudoadventicie. Cílové parametry protézy byly určeny výsledky testů základní metody fyzikálního testování - jednoosou tahovou zkoušku a inflačně-extenzní test, stejně jako další postupy, u humánních vzorků safeny. Klíčovou otázkou je technologie výroby kolagenní vrstvy protézy. I další postupy výroby však mohou mít nezanedbatelný vliv na vlastnosti cévní protézy - mezi takové patří tvrzení kolagenu, antitrombogenní ošetření vnitřního povrchu cévní náhrady a použití metody sterilizace. Autor se zabývá problematikou vývoje nové kolegenní složky třívrstvé cévní protézy z českého kapra, který se vyznačuje nižší antigenicitou ve srovnání s kolagenem bovinním. Porovnává standardní a purifikovaný kapří kolagen, který má nižší zastoupení reziduálního tuku s otázkou porovnání průchodnosti při...The development of vascular replacement for low flow rates is a topical issue. The model for developing the development of replacement properties, which are based on the idea of assuming the characteristics of the biological model - vena saphena and programming these properties into a model of constructed replacement is one of the possible directions of development. The presented replacement, which is the result of the work of the author's team, consists of three parts - a non-absorbable scaffold representing the media, and two absorbable collagen layers - pseudointima and pseudoadventice. Target parameters of the prosthesis were determined by test results of the basic physical testing method - uniaxial tensile test and inflation-extension test, as well as other procedures in human saphenous specimens. The key issue is the technology of producing the collagen layer of the prosthesis. However, other manufacturing processes can also have a significant impact on vascular prosthesis properties, such as collagen hardening, antithrombogenic treatment of the inner surface of the vascular replacement, and the use of a sterilization method. Furthermore, the author deals with the development of a new female component of the three- layer vascular prosthesis of the Czech carp, which is characterized by lower...II. chirurgická klinika - kardiovaskulární chirurgie 1. LF UK a VFN2nd Department of Surgery-Clinical Department of Cardiovascular Surgery First Faculty of Medicine1. lékařská fakultaFirst Faculty of Medicin

    Analysis of GMR heterostructures by SIMS

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    Studium vlivu depozičních parametrů na GMR heterostruktury metodou SIMS.Studies of influence deposition parameters on heterostructures by SIMS

    Diffusion Quantum Monte Carlo Calculations of Excited States of Silicon

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    The band structure of silicon is calculated at the Gamma, X, and L wave vectors using diffusion quantum Monte Carlo methods. Excited states are formed by promoting an electron from the valence band into the conduction band. We obtain good agreement with experiment for states around the gap region and demonstrate that the method works equally well for direct and indirect excitations, and that one can calculate many excited states at each wave vector. This work establishes the fixed-node DMC approach as an accurate method for calculating the energies of low lying excitations in solids.Comment: 5 pages, 1 figur

    The effect of blinds on workplace illuminance

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    The paper explores the effect of blinds on the workplace illuminance. The blinds are used to reduce solar load from the sunshine and decrease energy consumption for cooling in the overheated room. With blinds reducing inside illuminance the standards may not be fit and it is necessary add artificial lighting in this cases. It is important to correctly regulate daylight and eventually supplement it with artificial lighting to set the system for minimum energy consumption to meet all standard requirements. This paper presents the basic effect of the blinds on the internal illuminance of the workplace in the laboratory of lighting systems. This paper indicates that with increasing angles of blinds inside illuminance is decreasing. © The Authors, published by EDP Sciences, 2017

    Finite size errors in quantum many-body simulations of extended systems

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    Further developments are introduced in the theory of finite size errors in quantum many-body simulations of extended systems using periodic boundary conditions. We show that our recently introduced Model Periodic Coulomb interaction [A. J. Williamson et al., Phys. Rev. B 55, R4851 (1997)] can be applied consistently to all Coulomb interactions in the system. The Model Periodic Coulomb interaction greatly reduces the finite size errors in quantum many-body simulations. We illustrate the practical application of our techniques with Hartree-Fock and variational and diffusion quantum Monte Carlo calculations for ground and excited state calculations. We demonstrate that the finite size effects in electron promotion and electron addition/subtraction excitation energy calculations are very similar.Comment: 15 pages, 6 figures. To appear in Phys. Rev.

    The Concept of the Implementation of Present Evidence-based Knowledge and Technology into the Preparation of Sport Professionals

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    AbstractThe study assesses the feasibility of the concept of professional preparation of sport teachers and instructors that attempts to connect education and research activities with the emphasis on presenting evidence-based knowledge and new technologies. The seven-year-long international study involved 670-850 university students annually. Students participated directly in the research activities that were in compliance with the curricula of sport education study programs. The presented educational model describes possibilities and major limits how to provide dozens evidence-based knowledge of prospective sport professionals in the areas of physical activity monitoring, self-assessment of physical fitness and evaluation of sport preferences

    Quantum Monte Carlo calculation of Compton profiles of solid lithium

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    Recent high resolution Compton scattering experiments in lithium have shown significant discrepancies with conventional band theoretical results. We present a pseudopotential quantum Monte Carlo study of electron-electron and electron-ion correlation effects on the momentum distribution of lithium. We compute the correlation correction to the valence Compton profiles obtained within Kohn-Sham density functional theory in the local density approximation and determine that electronic correlation does not account for the discrepancy with the experimental results. Our calculations lead do different conclusions than recent GW studies and indicate that other effects (thermal disorder, core-valence separation etc.) must be invoked to explain the discrepancy with experiments.Comment: submitted to Phys. Rev.
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