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The list of national projects SAS

Institute of Construction and Architecture
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
Program: VEGA
Project leader: Mgr. Kocifaj Miroslav PhD.
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.
Duration: 1.1.2020 - 31.12.2023
Global Characterization of Skyglow
Globálna charakterizácia svetelného znečistenia
Program: SRDA
Project leader: Mgr. Kocifaj Miroslav PhD.
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.
Duration: 1.7.2019 - 30.6.2023
A multiscale flexoelectric theory and a new method for real-time detection of microcracks in dielectric materials
Multiškalova teória flexoelektricity a nové metódy pre detekciu mikrotrhlín v reálnom čase v dielektrických materiáloch
Program: SRDA
Project leader: Prof. Ing. Sládek Ján DrSc.
Annotation:Scientific base of the structural health monitoring (SHM) systems should be developed to prevent catastrophic failure of structures, decrease maintenance cost and guide construction. The SHM is especially important for high performance structures, where failure would lead to disasters. It requires a real-time monitoring of micro-cracks in structures. Usually piezoelectric materials are utilized in SHM as sensors. Conventional piezoelectric materials contain toxic lead and they have lower thermal stability. Therefore, the goal of the project is to design lead-free piezoelectric metamaterials with a functionality and piezoelectric response comparable to those of lead-oxide based piezoelectrics. While the piezoelectric property is non-zero only for select materials (noncentrosymmetric),the flexoelectricity is in principle non-zero for all materials. Flexoelectricity is a phenomenon widely existing in all dielectric materials. It couples the strain gradient developed in a dielectric material with its polarization. To utilize the flexoelectric effect the strain gradients have to be large and they are generated easily only at the nanoscale. A reliable computational method based on gradient theory has to be developed. Both material parameters higher order elastic and flexoelectric coefficients are determined on the base of atomistic model. The governing equations with the corresponding boundary conditions are derived from the variational principle. The FEM formulation is developed from the governing equations of gradient theory. The C1-continuous elements are applied to guarantee the continuity of variables and their derivatives in the element boundaries. Experimental methods are applied to verify new theoretical and computational approaches in flexoelectricity.
Duration: 1.10.2018 - 30.9.2021
Multiscale study and modelling of composite macrostructures
Multiškálové štúdium a modelovanie kompozitných makrokonštrukcií
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.
Duration: 1.1.2020 - 31.12.2023
The mechanisms of targeted resonant attenuation of microwave signals
Nežiadúci a cielený rezonančný útlm mikrovlnných komunikačných liniek
Program: Other projects
Project leader: Mgr. Kocifaj Miroslav PhD.
Duration: 1.4.2019 - 30.6.2021
Optimal design of micro/nano structures for metamaterials
Optimálny návrh mikro/nano konštrukcii pre metamateriály
Program: SRDA
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.
Duration: 1.7.2019 - 30.6.2023
Research and development of multi-component cementitious blends for special construction materials
Výskum a vývoj mnohozložkových cementových zmesí pre špeciálne konštrukčné materiály
Program: SRDA
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. 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 be used as biological shielding in power nuclear plant; 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 ones of the main factors which are the driving forces for the implementation of the submitted project.
Duration: 1.7.2020 - 30.6.2024
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.
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.
Duration: 1.1.2020 - 31.12.2023
Research of direct component of daylighting in architectural and interior environment
Výskum priamej zložky dennej osvetlenosti v architektonickom a interiérovom prostredí
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.
Duration: 1.1.2020 - 31.12.2022

The total number of projects: 9