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The presented study is focused on a novel approach in the design of composites based on magnesium oxychloride cement (MOC) material as alternative to construction materials widely used in building industry. The base of this approach lies in the enhancement of the MOC-matrix using tannic acid and carbon-based nanomaterials, namely graphene nanoplatelets and multi-walled carbon nanotubes. The use of the carbon nanomaterials in very low content is beneficial for the mechanical and macrostructural parameters of the composite, whereas the tannic acid was added for its possible ability to improve not only mechanical performance, but also the water resistance of the composite. A reference MOC sample, MOC with tannic acid sample and MOC with tannic acid and combination of graphene nanoplatelets and multi-walled carbon nanotubes were prepared and studied. All of the additives proved themselves beneficial for the matrix, resulting in a formation of composite applicable e.g., in construction industry. [ABSTRACT FROM AUTHOR]

REBCO bulk superconductors fabricated in large diameters or complicated geometries are desirable for a variety of engineering applications. Initiating crystal growth from multiple seed arrangements reduces the time of the melt-growth process of individual samples and can reduce the problems with microstructure further away from the seed. However, grain boundaries between regions introduced by multi-seeding can significantly reduce the flow of current due to crystallographic misalignment and the agglomeration of impurity phases. Unfortunately, REBCO single grains have intrinsically very low growth rates, which limits the sample size that can be achieved through the top-seeded melt growth process. A melting process based on the use of two or more seeds (so-called multiseeding) to control the nucleation and subsequent growth of bulk REBCO superconductors has been developed to fabricate larger samples. [ABSTRACT FROM AUTHOR]

This contribution deals with design and development of magnesium oxychloride cement (MOC) composites for extraterrestrial application. For the design of the composite, Martian soil simulant MGS-1 was used as a filler, in order to form a composite, which uses materials available at the locality of application. The designed composite contained 5 wt. % of MGS-1 (relatively to the content of MgO) and was prepared with two types of raw MgO powder with different purity. Overall four types of MOC-based material were prepared, analyzed using multiple types of analytical methods and mechanical tests and compared with each other. The influence of the Martian soil simulant on the MOC matrix was assessed, showing the high potential of such material in its intended environment of application. [ABSTRACT FROM AUTHOR]

Requirements for the production and properties of superconductors are constantly increasing, and currently, it is necessary to prepare these materials not only in larger diameters but also in large series. It is important to know what type of superconductor to choose for a particular type of application. The trapped field is a property that can be used in NMR/MRI devices, super strong hybrid electromagnets or vibration stabilizers. The levitation force of superconductors can be used in devices such as high-speed bearings, horizontal or vertical conveyors and high-speed trains. Preparing superconductors in larger series reduces the total required time and energy consumption. I this work the two larger batches of single-domain superconductors with diameter 28 mm based on YBCO and EuBCO were prepared and their superconducting properties such as levitation force and trapped magnetic field were measured and compared. [ABSTRACT FROM AUTHOR]

In this paper, the reference sample of Magnesium oxychloride cement (MOC) and a MOC-based composite with graphene and Lunar regolith simulant were prepared and analyzed. Graphene was added to the prepared composite in order to increase the strength, while the Lunar regolith simulant was used as a filler. The regolith simulant was analyzed using X-ray diffraction, X-ray fluorescence, sorption analyzer, laser diffraction, scanning electron microscopy and energy dispersive spectroscopy. The composite and the reference sample were analyzed with X-ray diffraction, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. Moreover, the mechanical properties and porosity were also determined. Despite a significant decrease in the mechanical properties, such material can find application on the lunar surface. [ABSTRACT FROM AUTHOR]

In this paper, a new construction material for extraterrestrial use is presented. As a base material for this novel composite, magnesium oxychloride cement (MOC), as a new eco-friendly alternative to Portland cement (PC) was used. To improve the mechanical properties of the composite, graphene nanoplatelets were used in a small amount. To make the composite as environmentally sustainable as possible a filler, simulant of the Martian soil, was used. This material had to be analyzed in order to determine its basic properties, such as chemical and phase composition, surface area particle size, and morphology. The designed composite was characterized using various methods to determine its chemical and mechanical properties. Also, a sample, which did not contain the Martian soil simulant was prepared in order to have a reference, to which the MOC-Martian soil simulant composite was compared. [ABSTRACT FROM AUTHOR]

In this paper, the 5Mg(OH)2·MgCl2·8H2O also known as magnesium oxychloride cement phase 5 (MOC-518) was prepared from pure MgO and MgCl2·6H2O. Before the synthesis, pure MgO was characterized by X-ray diffraction, X-ray fluorescence, sorption analyzer (BET) and laser diffraction. The kinetics of MOC-518 formation was analyzed by X-ray diffraction and by means of isothermal calorimetry. When the reaction was over, the sample was characterized in detail by scanning electron microscopy and energy dispersive spectroscopy. In addition, mechanical properties in time relation such as compressive and flexural strength, were determined. Results confirmed that the particle size as well as surface area of starting MgO significantly influence the phase formation rate of MOC-518. [ABSTRACT FROM AUTHOR]

The aim of this work is to design technology for recycling imperfectly grown superconducting ceramic discs of mixed copper oxides based on YBCO by dissolving in strong acid, reprecipitation and subsequent calcination of individual fractions. Unsuccessfully grown yttrium-containing crystals will first be ground and converted to a homogeneous powder. The powder is dissolved in nitric acid with an emphasis on optimizing the reaction parameters (concentration, temperature, reactant ratios) to recycle imperfectly grown crystals. In this work, the main aim is to isolate the individual components, including rare earths, and to design a procedure for the use of these materials for the preparation of new superconducting discs, which will then be investigated for mechanical and superconducting properties. YBCO discs, as well as individual fractions, will be analyzed in detail using scanning electron microscopy (SEM), X-ray fluorescence (XRF), thermogravimetry (TG), laser diffraction (LD) and X-ray powder diffraction (XRD). [ABSTRACT FROM AUTHOR]

In this contribution, the magnesium oxychloride cement was prepared using nano-MgO. The first part of this study deals with the preparation and analysis of nano-MgO. The analysis consisted of determination of its phase composition, surface area, and particle size by X-ray diffraction, laser diffraction and sorption analyzer (BET). In the second part of this study, the magnesium oxychloride phase was prepared using previously obtained nano-MgO and then analyzed by XRD, to determine its phase composition. The synthesis of highly reactive precursor was confirmed, showing the presence of Phases 3, 5 and 9. [ABSTRACT FROM AUTHOR]

Magnesium oxybromides are analogue substances to magnesium oxychlorides, commonly known as Sorel cements. In this contribution, we prepared and characterized pure Mg2(OH)3Br·4H2O. The phase composition was evaluated by X-ray diffraction. The chemical composition was analyzed using X-ray fluorescence and energy dispersive spectroscopy. Also, scanning electron microscopy and transmission electron microscopy was used to analyse the microstructure. In addition, thermal stability was tested using simultaneous thermal analysis. [ABSTRACT FROM AUTHOR]

Effects of SPS (Spark Plasma Sintering) and standard uniaxial pressing on the superconducting properties and microstructure of YBCO bulks were investigated. The pressed YBCO pellets were used for the Top-Seeded Melt Growth technique to manufacture single-domain YBCO bulks. The YBCO crystals were cut in half, polished and the microstructure was studied using scanning electron microscopy and optical microscopy. The study of the microstructure is very important for the possible improvement of mechanical and superconducting properties. In addition, the superconducting properties such as the trapped field and magnetic levitation force were measured and compared. [ABSTRACT FROM AUTHOR]

In this paper, the Mg3(OH)5Cl·4 H2O also known as magnesium oxychloride cement (MOC) phase 5 (P5) was prepared using pure MgO and MgCl2·6H2O. The sample was then characterized in terms of the phase formation kinetics, the chemical composition and its thermal behaviour. The surface morphology was analyzed using the scanning electron microscopy. The phase composition and the kinetics of formation were investigated by X-ray diffraction. The chemical composition was determined using the X-ray fluorescence and energy dispersive spectroscopy. Moreover, the simultaneous thermal analysis was used in order to characterize the thermal behaviour of Mg3(OH)5Cl·4 H2O. [ABSTRACT FROM AUTHOR]

Magnesium oxychloride cement (MOC) is an important material in building industry for its unique properties. In this contribution, we prepared and characterized pure Mg2(OH)3Cl·4H2O.. The phase composition and kinetics of formation was evaluated by X-ray diffraction, where diffractograms were observed continuously for 4 hours. The chemical composition was analyzed using X-ray fluorescence and energy dispersive spectroscopy. Also, scanning electron microscopy was used to analyse the microstructure. In addition, thermal stability was tested using simultaneous thermal analysis. [ABSTRACT FROM AUTHOR]

In this contribution, we would like to show that biomass ash coming from combustion of Miscanthus Giganteus can be used for fabrication of blended cement-based composites due to its high pozzolanic activity and suitable chemical nature. Biomass ash composition was characterized using X-ray fluorescence and energy dispersive spectroscopy. The phase composition was analyzed in detail by X-ray diffraction. Moreover, the thermal stability was analyzed using simultaneous thermal analysis. In the next step, the pozzolanic activity was analyzed using modified Chapelle test. Potentiometric method was used for pH measurement. Since the biomass ash was pozzolana active, it is potentially suitable as a pozzolana active admixture in cement, lime and alkali activated aluminosilicate composites. [ABSTRACT FROM AUTHOR]