2021 - Repozytorium publikacji - Politechnika Gdańska

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Manganese–Cobalt Based Spinel Coatings Processed by Electrophoretic Deposition Method: The Influence of Sintering on Degradation Issues of Solid Oxide Cell Oxygen Electrodes at 750 °C
- Elisa Zanchi
- Justyna Ignaczak
- Bartosz Kamecki
- Piotr Jasiński
- Sebastian Molin
- A Boccaccini
- Federico Smeacetto
2021 Pełny tekst Materials
This paper seeks to examine how the Mn–Co spinel interconnect coating microstructure can influence Cr contamination in an oxygen electrode of intermediate temperature solid oxide cells, at an operating temperature of 750 °C. A Mn–Co spinel coating is processed on Crofer 22 APU substrates by electrophoretic deposition, and subsequently sintered, following both the one-step and two-step sintering, in order to obtain significantly different densification levels. The electrochemical characterization is performed on anode-supported cells with an LSCF cathode. The cells were aged prior to the electrochemical characterization in contact with the spinel-coated Crofer 22 APU at 750 °C for 250 h. Current–voltage and impedance spectra of the cells were measured after the exposure with the interconnect. Post-mortem analysis of the interconnect and the cell was carried out, in order to assess the Cr retention capability of coatings with different microstructures.
Manufacturing and Recycling Impact on Environmental Life Cycle Assessment of Innovative Wind Power Plant Part 1/2
- Krzysztof Doerffer
- Patrycja Bałdowska-Witos
- Michał Pysz
- Piotr Doerffer
- Andrzej Tomporowski
2021 Pełny tekst Materials
Wind power plants are considered as ecologically-clean source of energy. However, manufacturing processes cannot be treated that way. Manufacturing processes consume huge amount of electrical and thermal energy and significant amount of materials, e.g. steel, polymers, oils and lubricants. All of the above could be potentially harmful for environment. There are not many works and publications regarding life-cycle analysis of wind power plants. This study objective is to use LCA to the manufacturing and utilization of a specific drag force driven wind turbine. The discussed innovative wind turbine is of the type which assures safety for prosumer application. Drag force driven turbines become more heavy than other types of lift driven turbines but in the same time their characteristic provides opportunity to use easily recyclable materials instead of materials like plastics or composites. The wider look through LCA tools, may change the perspective of view at that type of wind turbines.. Analyzed turbine has capacity of 15 kW and is located in Poland. LCA was carried out using Eco-indicator 99 method in eleven impact categories. Among all of the turbine components the highest negative impact was noted in the case of the tower. Wind turbine under consideration is characterized by high recycling potential. According to presented research recycling provides around 30% reduction of environmental impact.
Manufacturing and Recycling Impact on Environmental Life Cycle Assessment of Innovative Wind Power Plant Part 2/2
- Patrycja Bałdowska-Witos
- Krzysztof Doerffer
- Michał Pysz
- Piotr Doerffer
- Andrzej Tomporowski
- Marek Opielak
2021 Pełny tekst Materials
The process of conversion of wind kinetic energy into electricity in innovative wind power plant emits practically no harmful substances into the environment. However, the production stage of its components requires a lot of energy and materials. The biggest problem during production plan-ning process of an innovative wind power plant is selection of materials and technologies and, consequently, the waste generated at this stage. Therefore, the aim of this publication was to conduct an environmental analysis of the life cycle of elements of a wind turbine by means of life cycle assessment (LCA) method. The object of the research was a wind power plant divided into five sets of components (tower, turbine structure, rotors, generators, and instrumentation), made mainly of steel and small amounts of polymer materials. Eco-indicator 99 was used as an analytical procedure. The impact of the subjects of analysis on human health, ecosystem quality and re-sources was assessed. Among the analyzed components, the highest level of negative impact on the environment was characterized by the life cycle of the wind turbine tower. The application of recycling processes is reducing the negative impact on the environment in the perspective of the entire life cycle of all studied elements of the wind power plant construction.
Mapping negative unintended consequences of disruptive technologies use in smart cities
- Nina Rizun
- Magdalena Ciesielska
- Gabriela Viale Pereira
- Charalampos Harris Alexopoulos
2021
Smart cities governance (SCG) consists of both to foster technology-enabled innovation, and to utilize disruptive technologies (DT) outcomes and impacts to increase public value of urban services. Despite widespread discussion of DT benefits, scientific literature identifies multiple determinants of unintended negative consequences (UC) of DT deployment in smart city initiatives. By considering UC as the negative aspects resulting from underestimating or ignoring the scale of such consequences, this study analyses the objectives of SCG and the negative unintended effects of five selected DT initiatives on these objectives’ implementation. The main contribution of this paper is the identification of determinants of negative UC of Smart City disruptive technologies initiatives and identifying the structure of their impact on the SCG objectives. The results indicate the need to establish a new governance framework of UC in smart cities as a tool to support local governments dealing with the changes caused by DT use in the smart city ecosystem
Mapping of the Covid-19 Vaccine Uptake Determinants From Mining Twitter Data
- Anna Baj-Rogowska
2021 Pełny tekst IEEE Access
Opinion polls on vaccine uptake clearly show that Covid-19 vaccine hesitancy is increasing worldwide. Thus, reaching herd immunity not only depends on the efficacy of the vaccine itself, but also on overcoming this hesitancy of uptake in the population. In this study, we revealed the determinants regarding vaccination directly from people’s opinions on Twitter, based on the framework of the 6As taxonomy. Covid-19 vaccine acceptance depends mostly on the characteristics of new vaccines (i.e. their safety, side effects, effectiveness, etc.), and the national vaccination strategy (i.e. immunization schedules, quantities of vaccination points and their localization, etc.), which should focus on increasing citizens' awareness, among various other factors. The results of this study point to areas for potentially improving mass campaigns of Covid-19 immunization to increase vaccine uptake and its coverage and also provide insight into possible directions of future research.
Marian Żerebecki – saper, inżynier, wykładowca Politechniki Gdańskiej – mało znany, ale czy zapomniany?
- Witold Parteka
2021 Pismo PG
Artykuł przedstawia sylwetkę Mariana Żerebeckiego – sapera, inżyniera, wykładowcy Politechniki Gdańskiej
Marine and Cosmic Inspirations for AI Algorithms
- Marek Galewski
- Piotr Duba
2021 Pełny tekst Per mare ad astra
Artificial Intelligence (AI) is a scientific area that currently sees an enormous growth. Various new algorithms and methods are developed and many of them meets practical, successful applications. Authors of new algorithms draw different inspirations. Probably the most common one is the nature. For example, Artificial Neural Networks were inspired by the structure of human brain and nervous system while the classic Genetic Algorithm was inspired by the biological evolution process. One of the important areas of AI algorithms applications are optimization problems which can be encountered in practically all fields of science, technology, and everyday life. Amongst AI algorithms used to solve optimization problems, especially large, and still broadening group are swarm intelligence algorithms. They are nature-inspired, meta-heuristic algorithms which usually solve optimization problems by mimicking biological or physical phenomena. They are based mainly on observations of behaviours of various species of animals for example birds , ants , grasshoppers , bees , bats , wolves , fish , dolphins and many other or implement physics laws or environmental phenomena like laws of gravity , motion of galaxies , lightning formation , hydrologic cycle , water evaporation , etc. The general advantages of swarm optimization are: simplicity, easy implementation and the lack of the objective function gradient information requirement. They are usually fast converging and can bypass local optima. Despite large number of algorithms there is no one, ultimate algorithm that solves all types of problems (single- and multi-objective, uni- and multi-modal, with and without boundaries, etc.). Thus, there is a permanent need for more algorithms with new, original inspirations. The paper presents general advantages of swarm intelligence algorithms and a short review of selected, interesting optimization algorithms that draw inspirations from marine nature and cosmic space. These are Gravitational Search Algorithm, Artificial Fish Swarm Optimization, Krill Herd, Whale Optimization Algorithm and Salp Swarm Algorithm
Marine Fuel Sulphur Limit Impact on Air Pollution
- Dominik Kreft
2021 International Journal of Ecology and Development
The article presents calculation of Sulphur oxides percentage drop rate in marine industry recorded after 01.01.2020 when new limits, provided by International Maritime Organizations legislation, became effective. Ships’ SOx global emission was estimated and compared between 4th quarter 2019 and 1st quarter 2020. For more accurate estimation 3 seaside cities with big harbors were selected for statistical analysis. Noticeable SOx decrease was observed. In one case the drop was at similar level to theoretical. There were found significant correlations between heavy fuel oil bunker and SOx level in the air.
Massively parallel linear-scaling Hartree–Fock exchange and hybrid exchange–correlation functionals with plane wave basis set accuracy
- Jacek Dziedzic
- James C. Womack
- Rozh Ali
- Chris-Kriton Skylaris
2021 Pełny tekst JOURNAL OF CHEMICAL PHYSICS
We extend our linear-scaling approach for the calculation of Hartree–Fock exchange energy using localized in situ optimized orbitals [Dziedzic et al., J. Chem. Phys. 139, 214103 (2013)] to leverage massive parallelism. Our approach has been implemented in the ONETEP (Order-N Electronic Total Energy Package) density functional theory framework, which employs a basis of non-orthogonal generalized Wannier functions (NGWFs) to achieve linear scaling with system size while retaining controllable near-complete-basis-set accuracy. For the calculation of Hartree–Fock exchange, we use a resolution-of-identity approach, where an auxiliary basis set of truncated spherical waves is used to fit products of NGWFs. The fact that the electrostatic potential of spherical waves (SWs) is known analytically, combined with the use of a distance-based cutoff for exchange interactions, leads to a calculation cost that scales linearly with the system size. Our new implementation, which we describe in detail, combines distributed memory parallelism (using the message passing interface) with shared memory parallelism (OpenMP threads) to efficiently utilize numbers of central processing unit cores comparable to, or exceeding, the number of atoms in the system. We show how the use of multiple time-memory trade-offs substantially increases performance, enabling our approach to achieve superlinear strong parallel scaling in many cases and excellent, although sublinear, parallel scaling otherwise. We demonstrate that in scenarios with low available memory, which preclude or limit the use of time-memory trade-offs, the performance degradation of our algorithm is graceful. We show that, crucially, linear scaling with system size is maintained in all cases. We demonstrate the practicability of our approach by performing a set of fully converged production calculations with a hybrid functional on large imogolite nanotubes up to over 1400 atoms. We finish with a brief study of how the employed approximations (exchange cutoff and the quality of the SW basis) affect the calculation walltime and the accuracy of the obtained results.
Matematyka na zajęciach z arkuszy kalkulacyjnych
- Agnieszka Bartłomiejczyk
- Dawid Ptach
- Marcin Wata
2021 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Na zajęciach, zarówno w szkole, jak i na uczelni, do pokazania technicznej strony użycia arkusza kalkulacyjnego, tj.dostępnych funkcjonalności oraz organizacji danych, często wykorzystuje się proste zadania matematyczne. W naszym artykule zwracamy uwagę na potrzebę rozumienia przez użytkowników arkuszy kalkulacyjnych pojęć matematycznych, które umożliwiają odpowiednie przygotowanie danych oraz zinterpretowanie uzyskanych za pomocą narzędzi arkusza wyników. Zajęcia z Technologii informacyjnych, Arkuszy kalkulacyjnych czy z Zarządzania projektami są okazją do pokazania wagi interdyscyplinarności w nauce, w tym do motywowania, głębszego poznania i zrozumienia matematyki.
Materiały sorpcyjne wykorzystywane w maskach ochronnych
- Paulina Nowicka
- Marta Orciuch
- Sandra Orylska
- Sandra Rosa
- Dominika Sołtyszewska
- Natalia Łukasik
2021 Pełny tekst Analityka: Nauka i Praktyka
Od zarania dziejów ludzie starają się chronić przed chorobami zakaźnymi, stosując środki ochrony osobistej, do których należą maski ochronne. Z uwagi na obecnie panującą pandemię wirusa SARS-CoV-2, noszenie masek stało się normą w walce z koronawirusem. Jednak zagrożenia dla górnych dróg oddechowych nie stanowią wyłącznie wirusy, lecz również cząstki stałe zawieszone w powietrzu. Szczególnie w krajach wysoko uprzemysłowionych, narażenie na duże stężenie pyłów może przyczynić się nawet do śmierci, gdy dostaną się one do krwioobiegu. Z tego względu, noszenie masek może znacząco poprawić jakość zdrowia i życia. W tym artykule scharakteryzowano dostępne filtry w maskach ochronnych, do których należą membrany z nanowłókien polimerowych, filtry na bazie węgla aktywnego oraz filtry na bazie struktur metaloorganicznych (MOF). Przedstawiono także nowe rozwiązania, takie jak maski na bazie antybakteryjnych materiałów, które mają uskutecznić ochronę przed patogenami.
Mathematical approach to design 3D scaffolds for the 3D printable bone implant
- Wiktoria Wojnicz
- Marek Augustyniak
- Piotr Borzyszkowski
2021 Pełny tekst Biocybernetics and Biomedical Engineering
This work demonstrates that an artificial scaffold structure can be designed to exhibit mechanical properties close to the ones of real bone tissue, thus highly reducing the stress-shielding phenomenon. In this study the scan of lumbar vertebra fragment was reproduced to create a numerical 3D model (this model was called the reference bone sample). New nine 3D scaffold samples were designed and their numerical models were created. Using the finite element analysis, a static compression test was performed to assess the effective Young modulus of each tested sample. Also, two important metrics of each sample were assessed: relative density and surface area. Each new designed 3D scaffold sample was analyzed by considering two types of material properties: metal alloy properties (Ti-6Al-4V) and ABS polymer properties. Numerical analysis results of this study confirm that 3D scaffold used to design a periodic structure, either based on interconnected beams (A, B, C, D, E and F units) or made by removing regular shapes from base solid cubes (G, H, I units), can be refined to obtain mechanical properties similar to the ones of trabecular bone tissue. Experimental validation was performed on seven scaffolds (A, B, C, D, E, F and H units) printed from ABS material without any support materials by using Fused Deposition Modeling (FMD) technology. Results of experimental Young modulus of each printed scaffold are also presented and discussed.
Mathematical model of the energy consumption calculation during the pine sawn wood (Pinus sylvestris L.) drying process
- Aleksandra Konopka
- Jacek Barański
- Kazimierz Orłowski
- Dariusz Mikielewicz
- Ladislav Dzurenda
2021 Pełny tekst WOOD SCIENCE AND TECHNOLOGY
The article presents the modification of the existing mathematical model to calculate energy consumption during conventional drying process. Apart from energy consumption the model permits to estimate the time of high-temperature drying process. The drying medium is air and superheated steam mixture. The obtained calculation results were compared with conducted experimental tests of drying square-edged sawn sapwood timber (Pinus sylvestris L.). The pine sawn wood samples were dried according to three different drying modes, namely mild, normal and intense. The experiments were performed in a semi-industrial scale drying chamber. On the basis of the experimental research available, existing mathematical models of drying wood have been improved. The developed model included the following changes: a different drying time for each mode and type of drying medium (moisturized air or air and superheated steam mixture). The use of an intensive drying mode significantly reduced the drying process time. The developed mathematical model revealed that the energy consumption of the drying process increases with the intensity of the mode used.
Measured and predicted freeze-thaw days frequencies in climate change conditions in central Poland
- Arkadiusz Bartczak
- Halina Kaczmarek
- Michał Badocha
- Michał Krzemiński
- Sebastian Tyszkowski
2021 Pełny tekst PeerJ
The rate of progression of geomorphological phenomena is greatly influenced by freeze-thaw processes. In the face of air temperature increasing over the past few decades, a question of the future impact of these processes arises, notably in the temperate and cold climate zones. Using the mean, maximum and minimum daily air temperature data in the period 1951–2018 obtained from three weather stations located in the vicinity of Jeziorsko reservoir (central Poland), we have determined the mathematical correlation, described with a polynomial function, between the mean monthly air temperature and the monthly number of freeze-thaw days (FTD). A freeze-thaw day is a day when the maximum air temperature is above 0 C while the minimum air temperature equals or is below this threshold. The number of FTDs within the study area averaged 64–71 and demonstrated a downward trend of 2–4 FTDs/10 years. The study period (1951–2018), includes a clearly marked distinct sub-period (1991–2018), when the reservoir was in operation, which experienced 58–68 FTDs. Considering the assumed rise in temperature, one should expect a further, though slightly slower, decline in the future number of FTDs. Depending on the accepted model of the temperature increase, which for the area of Poland (Central Europe) in the perspective of 30 years oscillates between +1.1 to +1.3 C, the number of FTDs within the study area is expected to decline by −4.5 to −5.3 FTD, i.e. 6–7% and 5.4–5.5 FTD i.e. 8–9% respectively.
Measurement Campaign and Mathematical Model Construction for the Ship Zodiak Magnetic Signature Reproduction
- Jarosław Tarnawski
- Krystian Buszman
- Mirosław Wołoszyn
- Tomasz Rutkowski
- Adam Cichocki
- R. Józwiak
2021 Pełny tekst MEASUREMENT
The paper presents the partial work done within the framework of the EDA Siramis II project focused on magnetic signature reproduction of ships. Reproduction is understood here as the ability to determine the magnetic anomaly of the local Earth magnetic field in any direction and at any measurement depth due to the presence of the analysed object. The B-91 type hydrographic ship Zodiak was selected as the real case study. The work was divided into two main stages: the development of a measurement campaign taking into account physical measurements, and the development of a mathematical model on the basis of the measured values. The measurement campaign included: preparation of the measuring range, selection of equipment for the measurement of magnetic quantities and geographical location, and data recording while the ship passes the measuring point according to the designated course. As a result of the measurement campaign, magnetic flux density components were collected in different positions in relation to the measuring instruments and the ship's heading. A multi-dipole model was used to build the mathematical model in accordance with the idea of inverse modelling. The effectiveness of this model was previously checked on synthetic data of virtual ships generated using the finite element method. Experiments performed with simulation models were helpful in determining the structure of the model, the nature of the data, and the number of samples needed to properly determine the multi-dipole model parameters. The parameters were determined using the nonlinear least squares method according to the idea of data fitting. The classical Ridge and Lasso regularization methods were applied to prevent the developed multi-dipole model from overfitting. Other regularization methods based on GPS accuracy marks and modification of fitness functions were also considered. The verification was done using real data: the data generated by the model was compared with patterns recorded during the Zodiak measurement campaign. High degree of conformity of the shape of characteristics was obtained. Moreover, the correctness of model execution was confirmed by low values of quantitative indices such as RMSE and MAE representing modelling errors. The methodology presented in the paper is quite universal and can be used to determine the signatures of other ferromagnetic objects.
Measurement of Seafloor Acoustic Backscatter Angular Dependence at 150 kHz Using a Multibeam Echosounder
- Karolina Trzcińska
- Jarosław Tęgowski
- Paweł Poćwiardowski
- Łukasz Janowski
- Jakub Zdroik
- Aleksandra Kruss
- Maria Rucińska
- Zbigniew Łubniewski
- Jens Schneider von Deimling
2021 Pełny tekst Remote Sensing
Acoustic seafloor measurements with multibeam echosounders (MBESs) are currently often used for submarine habitat mapping, but the MBESs are usually not acoustically calibrated for backscattering strength (BBS) and cannot be used to infer absolute seafloor angular dependence. We present a study outlining the calibration and showing absolute backscattering strength values measured at a frequency of 150 kHz at around 10–20 m water depth. After recording bathymetry, the co-registered backscattering strength was corrected for true incidence and footprint reverberation area on a rough and tilted seafloor. Finally, absolute backscattering strength angular response curves (ARCs) for several seafloor types were constructed after applying sonar backscattering strength calibration and specific water column absorption for 150 kHz correction. Thus, we inferred specific 150 kHz angular backscattering responses that can discriminate among very fine sand, sandy gravel, and gravelly sand, as well as between bare boulders and boulders partially overgrown by red algae, which was validated by video ground-truthing. In addition, we provide backscatter mosaics using our algorithm (BBS-Coder) to correct the angle varying gain (AVG). The results of the work are compared and discussed with the published results of BBS measurements in the 100–400 kHz frequency range. The presented results are valuable in extending the very sparse angular response curves gathered so far and could contribute to a better understanding of the dependence of backscattering on the type of bottom habitat and improve their acoustic classification.
Measurement report: Spatial variations in ionic chemistry and water-stable isotopes in the snowpack on glaciers across Svalbard during the 2015–2016 snow accumulation season
- Elena Barbaro
- Krystyna Koziol
- Mats P. Björkman
- Carmen P. Vega
- Christian Zdanowicz
- Tonu Martma
- Jean-Charles Gallet
- Daniel Kępski
- Catherine Larose
- Bartłomiej Luks
- Florian Tolle
- Thomas Schuler
- Aleksander Uszczyk
- Andrea Spolaor
2021 Pełny tekst ATMOSPHERIC CHEMISTRY AND PHYSICS
The Svalbard archipelago, located at the Arctic sea-ice edge between 74 and 81∘ N, is ∼60 % covered by glaciers. The region experiences rapid variations in atmospheric flow during the snow season (from late September to May) and can be affected by air advected from both lower and higher latitudes, which likely impact the chemical composition of snowfall. While long-term changes in Svalbard snow chemistry have been documented in ice cores drilled from two high-elevation glaciers, the spatial variability of the snowpack composition across Svalbard is comparatively poorly understood. Here, we report the results of the most comprehensive seasonal snow chemistry survey to date, carried out in April 2016 across 22 sites on seven glaciers across the archipelago. At each glacier, three snowpits were sampled along the altitudinal profiles and the collected samples were analysed for major ions (Ca2+, K+, Na+, Mg2+, NH+4, SO2−4, Br−, Cl−, and NO−3) and stable water isotopes (δ18O, δ2H). The main aims were to investigate the natural and anthropogenic processes influencing the snowpack and to better understand the influence of atmospheric aerosol transport and deposition patterns on the snow chemical composition. The snow deposited in the southern region of Svalbard is characterized by the highest total ionic loads, mainly attributed to sea-salt particles. Both NO−3 and NH+4 in the seasonal snowpack reflect secondary aerosol formation and post-depositional changes, resulting in very different spatial deposition patterns: NO−3 has its highest loading in north-western Spitsbergen and NH+4 in the south-west. The Br− enrichment in snow is highest in north-eastern glacier sites closest to areas of extensive sea-ice coverage. Spatial correlation patterns between Na+ and δ18O suggest that the influence of long-range transport of aerosols on snow chemistry is proportionally greater above 600–700 m a.s.l.
Measurements of the Hydraulic Fluids Compressibility
- Leszek Osiecki
2021
Performance of the hydrostatic high-pressure drive systems is affected by the changes of working fluid’s volume. Presence of air bubbles in the fluid cause this problem to be even more serious. To study this phenomenon precise measurements of fluid’s bulk modulus are necessary. Differ-ent measurement methods are applied, but they are either limited to low pressure range or give inaccurate results. To solve the problem the new measurement device was built. It allows to directly measure volume changes of both pure fluid or fluid-air mixture within the wide pressure and temperature range. Both adiabatic and isothermal module may be determined, the tested fluid may be pure or aerated.. Measurements of different fluids were made including vegetable oils (rapeseed, sunflower and linseed), mineral oil and synthetic oil.
Measurements of the optical and thermal properties of the 2D black phosphorus coating
- Paulina Listewnik
- Małgorzata Szczerska
- Paweł Jakóbczyk
2021 Pełny tekst Materials Research Express
Black phosphorus is a 2D material, which properties are still being discovered. In this paper, the sensitivity to the temperature of a few-layer black phosphorus coating deposited, on the surface of a microsphere-based fiber-optic sensor, by a dip-coating method is presented. The coating was investigated after 2, 3, and 5 deposition cycles and during temperature growth from 50 °C to 300 °C in an interferometric setup. The intensity of the reflected signal increases with each applied layer. During the investigation of the thermal properties, in the range of 50 °C–200 °C, the polynomial growth rate of the reflected signal can be observed, whereas, for the temperatures over 200 °C, the measured peak intensity of the reflected signal stabilizes at a nearly constant level.
Measurements of Thermal Conductivity of LWC Cement Composites Using Simplified Laboratory Scale Method
- Marzena Kurpińska
- Jarosław Karwacki
- Artur Maurin
- Marek Kin
2021 Pełny tekst Materials
The implementation of low-energy construction includes aspects related to technological and material research regarding thermal insulation. New solutions are sought, firstly, to reduce heat losses and, secondly, to improve the environment conditions in isolated rooms. The effective heat resistance of insulating materials is inversely proportional to temperature and humidity. Cement composites filled with lightweight artificial aggregates may be a suitable material. Selecting a proper method for measuring the thermal conductivity of concrete is important to achieve accurate values for calculating the energy consumption of buildings. The steady state and transient methods are considered the two main thermal conductivity measurement approaches. Steady state is a constant heat transfer, whereby the temperature or heat flow is time independent. In the transient method, temperature changes over time. Most researchers have measured the conductivity of cement-based materials based on transient methods. The availability and cost of equipment, time for experimental measurements and measurement ability for moist specimens may be some of the reasons for using this method. However, considering the accuracy of the measurements, the steady state methods are more reliable, especially for testing dry materials. Four types of composites were investigated that differed in filler: natural aggregate, sintered fly ash filler, sintered clay and granular foam glass aggregate. The method of preparing the samples for testing is especially important for the obtained results. The samples, with a specific surface roughness, will show a lower coefficient of thermal conductivity by 20–30%; therefore, the selection of the type of contact layer between the plate of the measuring device and the sample is of particular importance.