Određivanje pomaka opterećenoga drvenog stolca primjenom korelacije digitalne slike

The subject of the research is a ready to assemble (RTA) chair constructed of plywood by a CNC machine. The standard test of seat and back of the chair according to the Czech Standard CSN EU 1728 was supplemented with an optical method of digital image correlation (DIC). The aim of the research was to discover mechanical principles of the construction and to develop a methodology of standardized furniture testing. Results of experimental measurement show the response of the chair construction in a form of displacement fields, strain fields, charts and vectors depicting displacement of the observed points. The results can be used to improve mechanical properties of the construction, as well as to develop a shape of the product or specific parts of the product. Besides furniture testing laboratories and research institutes, engineers from development departments of furniture making companies or industrial designers can easily use the presented method.Predmet istraživanja bio je stolac spreman na sklapanje (RTA), izrađen od uslojenog drva na CNC stroju. Standardni test sjedala i naslona stolca prema češkom standardu CSN EU 1728 dopunjen je optičkom metodom korelacije digitalne slike (DIC). Cilj istraživanja bio je otkriti mehanička načela konstrukcije te obogatiti metodologiju standardiziranog ispitivanja namještaja. Rezultati eksperimentalnih mjerenja prikazuju reakciju konstrukcije stolca u obliku polja pomaka, polja naprezanja te grafikona i vektora koji predočuju pomake promatranih točaka. Rezultati se mogu iskoristiti za poboljšanje mehaničkih svojstava konstrukcije, kao i za razvoj oblika proizvoda ili ispitivanih dijelova. Osim u laboratoriju za ispitivanje namještaja ili u istraživačkim institutima, prikazanom se metodom lako mogu koristiti inženjeri razvojnih odjela u tvrtkama za proizvodnju namještaja li industrijski dizajneri

Mn DOPING OF GaN LAYERS GROWN BY MOVPE

In this contribution we present a growth of Ga1-xMnxN layers by MOVPE. Mn doped GaN layers were grown with and without undoped GaN templates on (0001) sapphire substrates in a quartz horizontal reactor. For the deposition of Ga1-xMnxN layers (MCp)2Mn was used as a Mn – precursor. The flow of the Mn precursor was 0.2-3.2 μmol.min-1. The deposition of Ga1-xMnxN layers was carried out under the pressure of 200 mbar, the temperature 1050 °C and the V/III ratio of 1360. For the growth of high quality GaN:Mn layers it was necessary to grow these layers on a minimally partially coalesced layer of pure GaN. The direct deposition of GaN:Mn layer on the low temperature GaN buffer layer led to a three-dimensional growth during the whole deposition process. Another investigated parameter was the influence of nitrogen on the layer’s properties. A nearly constant ferromagnetic moment persisting up to room temperature was observed on the synthesized thin films

Pozitivizmus jako společenský jev

This entry entraps 1) crucial moments of existence of philosophy and science in the recent society; 2) problems of contraposition of philosophy and science in the contemporary western society; 3) problems of consolidation of results of science and philosophy as results of comprehensive knowledge of humanity. Philosophy of positivism does not entirely philosophical (or historical) trend, but primarily theoretical and methodological base. Important are views and doctrines too, in the western society consider by way of views and doctrines of science. Along is constantly mention about postmodern philosophy and mention about overcoming of the classical positivism

Racionalizace výroby těles ocelových šoupátek DN 200-500

PrezenčníNeuvedenoNeuveden

Identification and determination of trinitrotoluenes and their degradation products using liquid chromatography-electrospray ionization mass spectrometry

In the environs of ammunition plants and former military area, contaminations caused by explosives and their degradation products are of great environmental relevance. During the production of worldwide mostly used explosive compound - 2,4,6-trinitrotoluene its isomers were distributed into the environment. Therefore determination of 14 selected nitroaromatic compounds (trinitrotoluenes, amino dinitrotoluenes and diamino nitrotoluenes) by means of LC-MS-MS coupling utilizing electrospray ionization was developed. Therewith, these compounds were identified and quantified on the basis of specific precursor/product ion traces using the high selectivity and sensitivity of multiple reaction monitoring mode (MRM) of a triple quadrupole mass spectrometer. A new stationary phase designed especially for separation of EPA explosive mixture was used for separation of specific mixture of nitroaromatics compounds. Modification of HPLC properties enables base-line separation of all analytes and therefore improving of their MS identification and quantification. Limits of detection obtained using highly specific mass spectrometric detection MRM mode were in range 4-114 pg/μL. MS-MS qualification and quantification of explosives and their biodegradation products is feasible also in case of samples with complex matrix and high amount of co-eluting compounds. © 2010 Elsevier B.V. All rights reserved

Extraction and determination of trinitrotoluenes and products of their biotransformation in soil samples

The separation of a mixture of trinitrotoluenes (TNTs) and their metabolites by reverse phase liquid chromatography using different columns with octadecyl stationary phase is presented. The retention behaviour of a mixture of TNTs and their metabolites was studied under different chromatographic conditions. The mixture of methanol/water was used as a mobile phase in isocratic and gradient modes. The effect of content of organic modifier and temperature of mobile phase has been investigated. Very good RP-HPLC separation of 14 nitroaromatic compounds was obtained using stepped gradient elution. Different properties of extraction procedures for isolation of trinitrotoluenes and their metabolites from soil were tested. Experimental conditions of Soxhlet warm extraction (extractant type, extraction time) suitable for efficient extraction of individual analytes were studied. Recoveries over 80% for all studied compounds and over 90% for almost all (11 compounds) were obtained in short extraction time (1 hour). The formation of precipitate during the Soxhlet extraction was observed and the further treatment of extract was necessary. The amount of precipitate formed from an artificial soil was higher than that from a natural one. THF was found as the best solvent suitable for total dissolution of precipitate. © 2009 Taylor & Francis

The construction joint analysis of the villa Tugendhat interior furnishing

The functionalist villa Tugendhat in Brno is a first monument of modern architecture in the Czech Republic. This monument was registered in 2001 to the list of World Cultural and Natural Heritage by UNESCO. Among the most experts this building is usually regarded as a greatest work of German architect and designer Ludwig Mies van der Rohe. The complete renewal of this monument was ini­tia­ted due to unsatisfactory technical condition and because of the higher operational requirements. In this work we deal with the technical analysis of the villa Tugendhat interior furnishing, or more precisely with the structural analysis of its furniture joints. The goal of this work is to highlight the original construction and material solutions of the furniture in connection with the creation of production-technical documentation for the renewal. Project scope includes the complete constructional drawing documentation of the 53 pieces of furniture, documents relating to the surface treatment of the furniture, as well as documentation of manufacturing and constructional details. Described part of the project was prepared a few years ago by the Department of furniture, design and habitation. Nowadays, the project documentation is completed. Protracted legal disputes concerning this state contract still postpone the beginning of reconstruction of this monument

Methodology for creation of enlarged records of national authority files

Součástí grantového projektu „Tisky 16. století v zámeckých knihovnách České republiky“ (řešený v rámci programu NAKI) byl i úkol připravit metodiku pro tvorbu autorit, které bude možné využívat při zpracování tisků 16. století. Řešitelský tým projektu za NK ČR připravil tuto metodiku s ohledem na specifika tisků 16. století a v návaznosti na platnou (obecnou) metodiku tvorby autorit