BOND CONNECTIONS OF HIGH PERFORMANCE CONCRETE (HPC) AND STEEL: "EXPERIMENTAL VERIFICATION OF SELECTION GLUED FOR TWO DIFFERENT SURFACES OF STEEL"

This article deals with the test of selected adhesives for glued connection of high performance concrete and steel plates with various surface treatments. Results of this experiment can be used as a basis for the possible anchoring of concrete facade elements to the steel grate, the possible bonding of steel anchors on the surface of concrete facade elements. High performance concrete is a concrete that exceeds the compressive strength 100 MPa after 28 days. The second adherent is the uncoated steel and the steel with zinc coating as a second variant. Samples were tested in two different ways. The first experiment verified the single tensile strength of bond connection. The second test verified the shear strength, which is very important for connection designing

Study of pesticide degradation using advanced oxidation processes

V práci jsou vysvětleny a přiblíženy děje a pojmy související s problematikou degradace pesticidů pomocí pokročilých oxidačních procesů a jejich možnosti stanovování. Podstatou experimentální práce bylo vyvinutí a jednoduchá validace vytvořené metody pro vybrané pesticidy. Následné pokusy degradací těchto pesticidů ve vodě za pomocí pokročilých oxidačních metod a jejich stanovení. Cílem práce bylo porovnání zvolených metod oxidačních degradací a shrnutí výsledků pro navržení nejvhodnější metody pro jejich odstranění.In the master’s thesis are expleined and described proceses and terms related by problematic degradation of pesticides using advenced oxidation proceses and their possibilities of determinations. The essence of the experimental work was development and validate created method for determination of chosen pesticides. Degradation of this pesticides by advenced oxidation proceses and their determination after degradation. The aim of the work was compare chosen oxidation methods and summary of results for designe of the most appropriate method.

Design of a centrifugal compressor stage for a hybrid propulsion system

Tématem této práce je návrh stupně odstředivého kompresoru na základě předběžného návrhu hybridního turboeletrického pohonu pro leteckou aplikaci. V teoretické části jsou rozebrány jednotlivé části stupně odstředivého kompresoru a popsány návrhové metody kola a difuzoru a to jak pro fázi jednorozměrového návrhu, tak návrhu prostorového tvaru proudové cesty. V praktické části práce byl vytvořen program v prostředí MATLAB pro návrh geometrie kola a difuzoru, který byl následně využit k samotnému návrhu stupně kompresoru pro hybridní turboelektrický pohon výkonově odpovídající motoru Rotax 912 ULS. V poslední části práce byla provedena numerická analýza proudění v navrženém stupni a vytvořen koncepční návrh zkušebního zařízení pro jeho testování.The goal of this thesis is to design a centrifugal compressor stage for a specific preliminary design of a hybrid turboelectric propulsion system. The theoretical section deals with the description of the components of a centrifugal compressor stage and the theory needed for the design of the impeller and diffuser from the one-dimensional as well as the three-dimensional perspective. In the practical section, a program was developed in the MATLAB environment allowing automated design of impeller and diffuser geometry, which was subsequently used to generate parameters of a compressor stage to be used in a hybrid turboelectric propulsion system matching the power of a Rotax 912 ULS engine. In the last part of the presented work a numerical analysis of the proposed stage was performed, and a conceptual design of a testing facility was suggested

BOND CONNECTIONS OF HIGH PERFORMANCE CONCRETE (HPC) AND STEEL: "EXPERIMENTAL VERIFICATION OF SELECTION GLUED FOR TWO DIFFERENT SURFACES OF STEEL"

This article deals with the test of selected adhesives for glued connection of high performance concrete and steel plates with various surface treatments. Results of this experiment can be used as a basis for the possible anchoring of concrete facade elements to the steel grate, the possible bonding of steel anchors on the surface of concrete facade elements. High performance concrete is a concrete that exceeds the compressive strength 100 MPa after 28 days. The second adherent is the uncoated steel and the steel with zinc coating as a second variant. Samples were tested in two different ways. The first experiment verified the single tensile strength of bond connection. The second test verified the shear strength, which is very important for connection designing

LIGHTWEIGHT UHPC FACADE PANEL WITH LED DISPLAY

This article deals with the development of lightweight UHPC facade panel which also can serve as an LED display. Combining both functions into one gives the potential ability to create a LED display on the facade of the building. The article describes the experiences of the development and production of a small-format prototype facade panel, including the installation of LEDs and their electrical connection. The result of the research is the prototype of a 16mm thick small-format lightweight facade panel with a LED display for displaying text on two parallel lines. Thanks to the waffle lightening, the total material and weight savings are approximately 58% compared with the full cross section

EXPERIMENTAL VERIFICATION OF IMPREGNATED TEXTILE REINFORCEMENT SPLICING BY OVERLAPPING

This paper presents an experimental verification of impregnated textile reinforcement splicing by overlapping using tensile test of small textile reinforced concrete slabs before its using in the product. The specimen dimensions were designed 80×360mm and thickness approximately 18 mm. This specimen was reinforced using two pieces of impregnated flat technical fabric from carbon roving and epoxy resin. Two overlap lengths were designed using data from previous cohesion tensile tests and necessary anchoring length. The purpose of this experiment was experimental verification before flat reinforcement splicing by overlapping on the final product – furniture with textile reinforcement. This paper shows possible problems and complications in the anchoring of the textile reinforcements and in splicing by overlapping, the importance of the accuracy reinforcement position in the thin concrete cross-sectional area

GLASS WASTE POWDER UTILIZATION IN HIGH PERFORMANCE CONCRETE

This paper deals with investigation of high-performance concrete (HPC) with full replacement of the silica powder by the waste glass powder. The silica powder was replaced by two types of the waste glass powder, originated from different sources (waste glass powder from grinding jewelry and milling of municipal waste glass). The properties of the waste glass powder were examined and compared with the silica powder. The mechanical and durability properties of three HPC mixtures were experimentally verified. The bulk density, flexural strength, and compressive strength were tested on beams 40 × 40 × 160mm at age 28 and 60 days and after 0, 25, 50, 75 and 100 freeze-thaw cycles. There were observed slightly worse properties of mixtures with the waste glass powder in comparison with reference HPC

Geophysical survey at archaeological sites in northeastern Syria

From August 25 to September 4, 2008, geophysical surveys were carried out at the Neolithic, Chalcolithic, Bronze and Iron Age tell- and non-tell settlements in the Khabur region in Northeastern Syria (Syrian-Polish-Czech expedition) (Fig. 1). Four sites were prospected: Tell Arbid Abyad, Tell Arbid (West-hill), Khirbet Shane, Khirbet Bezi. The Scintrex Navmag SM-5 – Caesium Magnetometer was used for the measurement of the vertical gradient of the local magnetic field. The measurement resoluti..

Geophysical Survey at archaeological site Kaszaper, Békés County, Hungary

During the spring 2008 geophysical field survey was performed in south-eastern Hungary. The geophysical survey was carried out at the Bronze Age strongholds and nearby areas in the territory of Békés county. The aim of this article is to present the results from archaeological site Kaszaper. The archaeological site Kaszaper is situated on the north bank of Száraz-ér river, ca. 20 km to south-east of Orosháza. Main goal of the prospection was investigation of some interesting areas, chosen fol..