Igor Štubňa
YOU?
Author Swipe
View article: Correction: Húlan et al. The Influence of Fly Ash on Mechanical Properties of Clay-Based Ceramics. Minerals 2020, 10, 930
Correction: Húlan et al. The Influence of Fly Ash on Mechanical Properties of Clay-Based Ceramics. Minerals 2020, 10, 930 Open
In the original publication [...]
View article: Extension of the kinematics problem about the meeting of two bodies
Extension of the kinematics problem about the meeting of two bodies Open
The well-known problem about the meeting of two bodies starting from two different points and moving along their line is extended by the general case when the bodies move in a plane at a non-zero angle to the given line. The task is solved…
View article: Thermodilatometry of Quartz Porcelain Mixture Under Tensile Loading
Thermodilatometry of Quartz Porcelain Mixture Under Tensile Loading Open
Specimens composed of 50 wt.% kaolin, 25 wt.% quartz, and 25 wt.% feldspar were subjected to constant tensile stress during linear heating at 5 °C/min rate to measure their tensile deformation behavior. Deformation occurs at temperatures a…
View article: The Apparatus for Thermomechanical Analysis of Clay-based Ceramics
The Apparatus for Thermomechanical Analysis of Clay-based Ceramics Open
A dynamic thermomechanical analysis (D-TMA) apparatus is described for measuring the resonant frequency of the flexural vibration and the internal damping of the sample using the impulse excitation technique (IET). Since the measurement is…
View article: Electric properties of anorthite ceramics prepared from illitic clay and oil shale ash
Electric properties of anorthite ceramics prepared from illitic clay and oil shale ash Open
Electrical properties during firing of anorthite ceramic prepared from mixtures of illitic clay (from Northeastern Hungary) and fly ashes (obtained from circulating fluidized bed combustion – IA4 and pulverized firing – ID4) with high cont…
View article: Thermal Behavior of Ceramic Bodies Based on Estonian Clay from the Arumetsa Deposit with Oil Shale Ash and Clinker Dust Additives
Thermal Behavior of Ceramic Bodies Based on Estonian Clay from the Arumetsa Deposit with Oil Shale Ash and Clinker Dust Additives Open
The thermal behavior of green clay samples from the Arumetsa and Füzérradvány deposits (Hungary) and the influence of two new types of Estonian oil shale (OS) ashes and cement bypass dust (clinker dust) additives on it were the objectives …
View article: The Sonic Resonance Method and the Impulse Excitation Technique: A Comparison Study
The Sonic Resonance Method and the Impulse Excitation Technique: A Comparison Study Open
In this study, resonant frequencies of flexurally vibrating samples were measured using the sonic resonant method (SRM) and the impulse excitation technique (IET) to assess the equivalency of these two methods. Samples were made from diffe…
View article: Study of Thermooxidation of Oil Shale Samples and Basics of Processes for Utilization of Oil Shale Ashes
Study of Thermooxidation of Oil Shale Samples and Basics of Processes for Utilization of Oil Shale Ashes Open
A circular economy becomes an object of actual discussions as a real alternative to the existing linear economy system. The problem is actually in Estonia also, first of all in the sector of heat and power production which based mainly on …
View article: Young’s Modulus of Different Illitic Clays during Heating and Cooling Stage of Firing
Young’s Modulus of Different Illitic Clays during Heating and Cooling Stage of Firing Open
Dynamical thermomechanical analysis of 5 illite-based clays from deposits in Slovakia, Estonia, Latvia, and Hungary is presented. The clays consist of illite (37–80 mass%), quartz (12–48 mass%), K-feldspar (4–13 mass%), kaolinite (0–18 mas…
View article: The Influence of Fly Ash on Mechanical Properties of Clay-Based Ceramics
The Influence of Fly Ash on Mechanical Properties of Clay-Based Ceramics Open
Elastic properties of mixtures of illitic clay, thermal power plant fly ash (fluidized fly ash—FFA and pulverized fly ash—PFA), and grog were investigated during the heating and cooling stages of the firing. The grog part in the mixtures w…
View article: Contents
Contents Open
Room temperature impact consolidation and application to ceramic coatings
View article: Development of stress on quartz grain in illite ceramics during cooling stage of firing
Development of stress on quartz grain in illite ceramics during cooling stage of firing Open
If the volume fraction of quartz in traditional ceramics is higher than 10% then the use of Selsing's formula is questionable. A model of two concentric spheres, in which the inner sphere is a quartz grain and its spherical cladding is gla…
View article: Influence of Glass Additions on Illitic Clay Ceramics
Influence of Glass Additions on Illitic Clay Ceramics Open
A mixture of an illitic clay and waste glass was prepared and studied during the sintering process. The illitic clay, from the Liepa deposit (Latvia), and green glass waste (GW) were disintegrated to obtain a homogeneous mixture. The addit…
View article: Young’s modulus of prefired quartz porcelain in a temperature range of 20–1200 °C
Young’s modulus of prefired quartz porcelain in a temperature range of 20–1200 °C Open
Green samples (50 w/% of kaolin, 25 w/% of quartz and 25 w/% of feldspar) are prefired up to 400-1200 °C and analyzed during their second firing.Thermogravimetry, thermodilatometry and dynamic thermomechanical analyses are performed in a r…
View article: Evolution of AC conductivity of wet illitic clay during drying
Evolution of AC conductivity of wet illitic clay during drying Open
The evolution of the AC electrical conductivity during drying as well as the relationship between sample volume and moisture of green illite samples were investigated. The samples were prepared from illitic clay (80 mass % illite, 4 mass %…
View article: Acoustic Emission During Firing of the Illite-Based Ceramics with Fly Ash Addition
Acoustic Emission During Firing of the Illite-Based Ceramics with Fly Ash Addition Open
In this work, illite-based ceramic body with power plant y ash addition (60 wt.% of illite, 30 wt.% of y ash and 10 wt.% of illite red at 1100 • C) was investigated by the thermal analysis techniques (dierential thermal analysis, thermodil…
View article: THERMOMECHANICAL ANALYSIS OF ILLITE FROM FÜZÉRRADVÁNY
THERMOMECHANICAL ANALYSIS OF ILLITE FROM FÜZÉRRADVÁNY Open
Young’s modulus of green illite from Füzérradvány (Hungary) was measured in-situ in the temperature interval 20 °C – 1100 °C and auxiliary analyses DTA, TG and TDA, XRD and EGA, were also performed. It was found that a removal of the physi…
View article: DC CONDUCTIVITY OF CERAMICS WITH CALCITE WASTE IN THE TEMPERATURE RANGE 20 - 1050C
DC CONDUCTIVITY OF CERAMICS WITH CALCITE WASTE IN THE TEMPERATURE RANGE 20 - 1050C Open
The temperature dependences of the electrical DC conductivity of calcite waste, kaolinite and illite based ceramics were measured in the temperature range of 20 - 1050oC. The ceramic mass that was used was a mixture of 60 wt. % kaolinitic-…
View article: Uncertainty Of The Measurement Of DC Conductivity Of Eramics At Elevated Temperatures
Uncertainty Of The Measurement Of DC Conductivity Of Eramics At Elevated Temperatures Open
The electrical DC conductivity is measured at room and elevated temperatures on green ceramic samples prepared from kaolin. The arrangement of the sample, with two platinum wire electrodes inserted in the kaolin prism that was used is suit…