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Information Page of SAS Organisation

Project

Institute of Construction and Architecture

National Projects

DIFFUSE - Diffuse light in urban environment: A new model which embraces the optical properties of a local urban atmosphere

Difúzne svetlo v mestskom prostredí: nový model zohľadňujúci vlastnosti lokálnej atmosféry

Duration: 1. 1. 2020 - 31. 12. 2023
Program: VEGA
Project leader: Mgr. Kocifaj Miroslav DrSc.
Annotation:Due to elevated contamination by aerosols the diffuse light field in an urban environment differs from what we observe in city surroundings. The impacts on indoor daylight climate from different atmospheric turbidity conditions are also linked to emission sources in a city. Specifically, industry, public transportation, or construction work can produce particles that remain suspended in urban air for days or weeks and change the diffuse-light signatures. No quantification of the phenomena exists, no designed experiments have been performed and the theoretical development is in its infancy. Predictions from the present models are not accurate enough, so it is a great challenge of this project to develop a new optical model of urban atmosphere that 1) accounts for local scale parameters, 2) is applicable to arbitrary conditions, 3) can improve predictions of the diffuse-light patterns in a city, and 4) can be used by experts who deal with daylight and daylighting technologies.

Termomechanics - Effect of nano-, micro-, and meso-nonhomogeneities in the macroscale thermomechanical performance of composite structure members

Efekt nano-, mikro- a mezo-nehomogenít na makro termomechanické chovanie sa kompozitných konštrukcií

Duration: 1. 2. 2022 - 31. 12. 2023
Program: APVV
Project leader: Prof. Ing. Sládek Ján DrSc.
Annotation:This project is aiming to develop methods for the analysis and optimization of the thermomechanical performance of nonhomogeneous structural members operating under thermal, electrical, and mechanical loadings. By aggregating achievements of both the Ukrainian and Slovak partners in the area of thermomechanics of nonhomogeneous structures and non-classical theories of continuum mechanics, we intend to develop advanced techniques for estimating effects of accumulated nano-, micro- and meso-nonhomogeneities in the macroscale performance parameters with account for the size effect, which were failed to be captured when utilizing the homogenization methods. The linear response of the electric polarization of the solids to the temperature gradient and coupled electro-elastic fields caused by a thermal inclusion in isotropic solids is to be studied based on the relations of a local gradient theory of electro-thermo-elasticity. The results are expected to improve the estimation of the thermoelastic performance of structural members and prediction of the feasible material profiles for nonhomogeneous composites for desired operational performance based on their functional designation.

SKYGLOW - Global Characterization of Skyglow

Globálna charakterizácia svetelného znečistenia

Duration: 1. 7. 2019 - 30. 6. 2023
Program: APVV
Project leader: Mgr. Kocifaj Miroslav DrSc.
Annotation:In spite of the enormous progress in light pollution (LP) research since Garstang, subsequent theories are still limited to homogeneous skies, while the propagation of artificial light at night (ALAN) under broken cloud arrays remains largely unexamined. Due to its negative impacts, ALAN is currently one of the most pressing environmental concerns in the public eye. Thus major concerns were raised after experimental results showed that the predicted distributions and amplitudes of the ALAN differ from what we regularly observe in nature. Also, the mechanism of multiple scattering and optical distortion due to aerosols are both poorly described. This project will bring a fundamental understanding and satisfactory treatment of ALAN, while addressing the principal question: “How and to what extent the properties of both the artificially lit surface of Earth and the atmosphere can interact together, resulting in new means in the characterization and potential manipulation of ALAN”. We propose to 1) derive novel formulations and solutions to the light field in the nocturnal atmosphere with arbitrary cloud configurations; 2) uncover spectral “light-scattering and polarization fingerprints” that distinct types of clouds and aerosols can have in different parts of the sky; and 3) identify the manner in which both the atmosphere and light emissions from ground sources control ALAN. This could revolutionize the characterization of LP sources globally and have unexpected consequences in current developments in various fields. Overall, the project has great potential to open doors into a new research area with important applications in astronomy, lighting engineering, urban planning and also satellite remote sensing of aerosols at night, to which no competitive alternatives yet exist. The significance and novelty of the work will also lead to the acquisition of knowledge necessary to explain anomalous polarization features, or ALAN effects, due to compact and diffuse cities.

Material composition and properties of Self-Compacting Heavyweight Concrete

Materiálové zloženie a vlastnosti samozhutniteľných ťažkých betónov

Duration: 1. 1. 2021 - 31. 12. 2023
Program: VEGA
Project leader: Prof.Dr.Ing. Palou Martin-Tchingnabé
Annotation:The project is based on the development of heavyweight and self-compacting concretes based on cementitious composites containing admixtures (blast furnace slag, metakaolin and ground limestone), heavy aggregates (magnetite, barite or mixtures thereof) and superplasticizers. The project will determine the chemical composition of individual concrete components, including the presence of isotopes, heat during the hydration of cementitious composites, optimized grading curve of heavy aggregates and concrete composition so that the examined material has a bulk density more than 3000 kg / m3 and meets the requirements of self-compacting concretes, which means the capability to compact without any compaction force even at very dense reinforcement, without segregation and sedimentation of its constituents as determined by V-funnel and L-form. Short and long-term mechanical and physical properties of the resulting concrete will be investigated. Self-compacting heavyweight concretes have potential applications in nuclear power plants and in areas exposed to long-term nuclear radiation.

MEMOLIPO - Measuring and Modelling Light Pollution

Meranie and modelovanie svetelného znečistenia

Duration: 1. 9. 2022 - 31. 8. 2025
Program: SASPRO
Project leader: Dr. Wallner Stefan BSc MSc
Annotation:This project aims to investigate various approaches in measuring and modelling of the global phenomenon of light pollution, artificial light at night which is misdirected, overilluminated and/or makes use of harmful light. The ever-worsening phenomenon impairs not only the visibility of objects on the night sky, furthermore it is a major threat for all organisms worldwide, including human health suffering from impacts. Research goals of MEMOLIPO include a greater understanding of atmospheric impacts on the night sky brightness and how currently used measurement devices can show new approaches in their application. Firstly, light monitoring network data underly strong seasonal variations which can potentially falsify long-term analyses of light pollution development. Such must be included in order to rightly give statements about increases or decreases in night sky brightness values. Another research issue is the impact caused by atmospheric elements like the aerosol optical depth. Latter will be investigated by meteorological ceilometer backscatter data, providing data for this issue in an unprecedented accuracy. Furthermore, airborne vehicles will be tested as potential devices to characterize atmospheric layers. Moreover, it will be tested if easy retrievable ground-based measurements can approximate the city emission function, a very important input for theoretical modelling. And finally, allsky measurements will show, how far light domes from light emitting cities are visible and could influence night skies above natural protected areas. Results from this project lead to important insights in the understanding of skyglow phenomena and serve as inputs for modelling approaches in the future. Outcomes shall also be used for research disciplines of other fields, since it creates new fundaments for nature related studies in, e.g., ecology, biology and environmental physics, or technical studies like lighting management, sustainability and energy saving purposes.

Multiscale study and modelling of composite macrostructures

Multiškálové štúdium a modelovanie kompozitných makrokonštrukcií

Duration: 1. 1. 2020 - 31. 12. 2023
Program: VEGA
Project leader: Prof. RNDr. Sládek Vladimír DrSc.
Annotation:The research project deals with the 2nd order two-scale computational homogenization procedure for modelling composite structures responses. Using the 2nd order homogenization approach, the multiscale analysis may describe more complex deformation modes than the standard 1st order homogenization. The determination of effective material coefficients including those staying at higher-order derivatives of field variables are needed in gradient theory. This can be done by comparing the solutions of certain appropriate boundary value problems (BVP) on the macro- and micro-level. In the microstructural analysis, the microstructural inhomogeneity is modelled and the BVP on the RVE are solved using ordinary local continuum theory. The higher-order continuity requirements in the macro-level formulation can be met by applying C0 continuous approximation independently to primary fields and their gradients, with obeying the kinematic constraints between approximations by collocation at some internal points of elements.

Metamaterial - Optimal design of micro/nano structures for metamaterials

Optimálny návrh mikro/nano konštrukcii pre metamateriály

Duration: 1. 7. 2019 - 30. 6. 2023
Program: APVV
Project leader: Prof. Ing. Sládek Ján DrSc.
Annotation:Advanced metamaterials for health monitoring of structures are analysed in the project for optimal design. The piezoelectric response is observed in metamaterials if large strains are occurred in structures. Large strains are observed mainly in nano-sized structures. The classical continuum mechanics cannot be applied for such structures, since it is indifferent to the material microstructure. The intrinsic limitations of classical elasticity are overcome in advanced continuum models. The nano-sized structures with flexoelectric properties can be analysed successfully. For this purpose, the key task is to determine the higher-order elastic and flexoelectric coefficients in flexoelectric gradient theory. Due to missing experimental methods to obtain these coefficients, a numerical experiments are employed. Unknown flexoelectric coefficient is obtained by fitting the results by gradient theory with microsctructural analysis. Microstructure is not modelled in the gradient theory. The variational principle is applied to derive the governing equations with bearing in mind the constitutive equations leading to both the direct and converse flexoelectricity phenomena. The finite element method (FEM) and meshless formulations are developed to solve problems of flexoelectricity. The mixed FEM is developed in theproject, where the C0 continuous interpolation is applied independently for displacement and displacement gradients. Similarly the electric potential and electric intensity vector are approximated by C0 elements. The kinematic constraints between strains and displacements are satisfied by collocation at some cleverly chosen internal points in elements. The attention is paid also to treatment of surface stress effect important in nano-sized structures. The former elegant mathematical theory incorporating surface stresses in elasticity given by Gurtin and Murdoch is extended here to piezoelectricity.

Study of multicomponent cement material degradation under conditions simulating CO2 enriched geothermal environment

Štúdium degradácie viaczložkových cementových materiálov v dôsledku uhličitej korózie v podmienkach simulujúcich geotermálne vrty

Duration: 1. 1. 2021 - 31. 12. 2024
Program: VEGA
Project leader: Ing. Kuzielová Eva PhD.
Annotation:Justness of detailed study of degradation due to CO2 enriched geothermal environment is conditioned by development of new multicomponent, even lightweight, cementitious materials, which can be used for cementing in geothermal wells as well as by potential of geological sequestration of CO2. The project is focused on complex investigation of degradation mechanism at high temperatures and pressures, which is simultaneously affected by composition of geothermal water, hydration, pozzolanic and latent hydraulic reactions, but also by high-temperature transformations of primary reaction products. It is important to study carbonic corrosion from initial stage of hydration and to focus on synergism of different types of reactions in dependence on composition, physical and chemical basis of the used additives. The investigation under the conditions affecting kinetics and thermodynamics of reactions and evaluation of their impact on utility properties will allow the optimization of multicomponent cement compositions.

MULCEM - Research and development of multi-component cementitious blends for special construction materials

Výskum a vývoj mnohozložkových cementových zmesí pre špeciálne konštrukčné materiály

Duration: 1. 7. 2020 - 30. 6. 2024
Program: APVV
Project leader: Prof.Dr.Ing. Palou Martin-Tchingnabé
Annotation:The study of chemistry, phase evolution, and phase equilibrium during the hydration of multicomponent cementitious materials is a key challenge in the development of construction materials with high performance. Therefore, 1. the present project deals with the complex study of the effect of normal and hydrothermal curing conditions on hydration reaction of multicomponent cementitious binders for the objective of optimizing the composition of cementitious composites for high-temperature hydrothermal wells; 2. the project will develop heavyweight concrete based on the optimized composition of multicomponent cementitious binders and high-density aggregates. The concrete design will take into consideration the radioactive isotopes, in order to minimize the activation effect of gamma and neutron radiations, when it comes to being used as biological shielding in power nuclear plants; 3. the purpose of the present project is the development of advanced concrete materials, unique in its kind; Fiber-Reinforced Heavyweight Self-Compacting Mortars with special protection properties against ballistic missiles. The common denominator of these objectives is the chemistry of hydration reaction, including kinetics and mechanisms, phase evolution, and equilibrium of composites comprising Ordinary Portland (OPC) cement and Supplementary Cementitious Materials (SCMs). Different curing regimes (ordinary, hydrothermal), complex chemical analysis including radioactive isotopes of each ingredient, the particle size distribution of binders and aggregates are some of the main factors which are the driving forces for the implementation of the submitted project.

The energy efficiency of an innovative BIPV/T-TE-PCM module with PCM passive cooling

Výskum energetickej účinnosti inovatívnych BIPV/T článkov chladených PCM technológiou.

Duration: 1. 1. 2020 - 31. 12. 2023
Program: VEGA
Project leader: RNDr. Kómar Ladislav PhD.
Annotation:The objective of the presented proposal is to evaluate the efficiency of an innovative BIPV/T-TE-PCM (TE, thermoelectric; PCM, phase change material) for which little or no information is available. The emphasis is the operational performance assessment of proposed BIPV/T-TE-PCM module under practical conditions. The application of an integration model requires its coupling the building energy simulation with solar radiation availability models. The integration of PCM into a photovoltaic cell is important in terms of passive cooling of the panel, whose efficiency decreases with increasing temperature and also because of its prolonged service life, as thermal expansion can cause mechanical stress to the individual cell layers. In addition, the energy stored in the PCM will allow it to be used in the next phase, e.g. for water heating. The results will be structured in terms of the assessment analysis of this innovative BIPV/T-TE-PCM façade toward improving thermal comfort and energy efficiency of buildings.

ReDirCom - Research of direct component of daylighting in architectural and interior environment

Výskum priamej zložky dennej osvetlenosti v architektonickom a interiérovom prostredí

Duration: 1. 1. 2020 - 31. 12. 2022
Program: VEGA
Project leader: doc. Ing. Darula Stanislav CSc.
Annotation:Development in daylighting research is directed to better utilization of skylight and sunlight.Evaluation according to the most unfavourable condition is reasing and climatic approach of annual daylight utilization is introduced.Research of diffuse aylight availability has brought methodology of the standard interior daylighting evaluation.The availability of the direct component of the global illuminance which contributes to the dynamics of visual environment and influences physiological functions of human body is not yet explored. Sun radiation is the main source of life on the Earth.In the urban area the important role plays architectural formation of environment.The building and architecture are seen as a static element with given attributes.New approach requires solutions of adaptable and flexible forms based on the diversity. Project will search availability of direct illuminance, influence of sun radiation on the quality of the interior environment and adaptable and flexible architectural forms.

Projects total: 11