Wyniki wyszukiwania - Biblioteka Nauki

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Thermovisual measurements of 3D printing of ABS and PLA filaments

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Zgryza Ł. , Raczyńska A. , Paśnikowska-Łukaszuk M.

Advances in Science and Technology. Research Journal

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2018

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tom Vol. 12, no 3

266--271

EN

This paper presents the use of 3D printing and discusses two types of materials used in 3D printing, i.e. ABS (Acrylonitrile Butadiene Styrene) and PLA (Polylactide). Next, it presents the thermovisual measurementscarried out on 3D printed samples (FDM method - fused deposition modelling) of these materials. The temperature zones that occurred during printing were determined. The geometrical dimensions of samples from the same material that were printed under different conditions were compared. The height of the printed object has a large influence on temperature distribution on its surface and the printing time does not differ significantly when printing with PLA or ABS.

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Analysis of heat transfer in building partitions with the use of computational fluid dynamics tools

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Urzędowski A. , Styczeń J. , Paśnikowska-Łukaszuk M.

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tom T. 10, nr 3

48--51

EN

The article presents the mechanisms of heat exchange in building partitions along with a description of the phenomena occurring there.The methods of heat transport on selected examples of the construction of sandwich building walls were presented and discussed. A review of the methods allowing to determine the heat fluxvalue by means of analytical methods and simulations based on numerical analyzes was carried out. The methodology of solving thermal problems has been presented, indicating the complexity of the phenomena occurring at the contact points of surfaces, for which the correct characteristics should be selected in more than one selected form of determining temperature distributions.Heat transport simulation was performed in ANSYS Fluent 2020 R2 software. The value of the heat flux density flowing through the outer wall of a single-family house located in Lublin, Poland was analytically determined. Three different structural wall solutions were adopted: one, two and three-layer. The obtained results were presented in a tabular manner, allowing for a clear verification of the correctness of the calculations performed with both selected methods.

PL

W artykule przedstawiono mechanizmy wymiany ciepła w przegrodach budowlanych wraz z opisem zjawisk tam zachodzących. Przybliżonoi omówiono sposoby transportu ciepła na wybranych przykładach konstrukcji warstwowych ścian budowlanych. Przeprowadzono przegląd metod pozwalających na wyznaczenie wartości gęstości strumienia ciepłana drodze metod analitycznych oraz symulacji opartych na analizach numerycznych. Przedstawiono metodologięrozwiązywania zagadnień cieplnych wskazując na złożoność zjawisk zachodzących w miejscach kontaktu powierzchnidla których poprawnej charakterystyki należy przyjąć więcej niż jedną wybraną formę wyznaczenia rozkładów temperatury. Wykonano symulację transportu ciepła w oprogramowania ANSYS Fluent 2020 R2 oraz wyznaczono analitycznie wartość gęstości strumienia ciepła przepływającego przez ścianę zewnętrzną domu jednorodzinnego posadowionego w Lublinie w Polsce. Przyjęto trzy różne pod względem konstrukcyjnym rozwiązania ścian: jedno, dwu i trój warstwowe. Otrzymane wyniki przedstawione zostały w sposób tabelaryczny umożliwiając przejrzystą weryfikację poprawności wykonanych obliczeń obydwoma wybranymi metodami.

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Improving the Calibration of Surface Time Domain Reflectometry Sensors for Moisture Evaluation of Building Materials Using the Analysis of Covariance Method

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Futa A. , Jastrzębska M. , Paśnikowska-Łukaszuk M. , Wośko E. , Suchorab Z.

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tom Vol. 17, no 5

326--336

EN

The paper presents the models for moisture evaluation using a set of the reflectometric sensors in some types of building materials. The readouts reveal the relationship between the building material moisture, being assessed gravimetrically and the apparent permittivity values obtained by the TDR (Time Domain Reflectometry) method and surface sensors. Based on the readouts, equations describing this relationship were derived. These types of equations function as calibration equations and are used to calibrate the sensors. Most of the equations used to describe the examined relationships are linear regression. These equations very often refer to specific materials and cannot be applied to others that differ in density or chemical composition, which is the cause of many incorrect measurements. In this article, we propose the use of the analysis of covariance method (ANCOVA) for the analysis of reflectometric data. Using this method, it will be possible to determine the moisture content of materials, regardless of their type and construction of the sensor, which can significantly improve moisture measurements using the reflectometric method. For comparative aims data achieved in conducted research were analyzed using both traditional linear regression models and using the analysis of covariance method (ANCOVA). Both types of fitting models are discussed and their quality was compared in terms of accuracy expressed by the Residual Standard Error (RSE), the Root Mean Square Error (RMSE) and the determination coefficient (R2) values. The paper showed that the use of the ANCOVA method allows for improvement the fit of the model in terms of the determination coefficient by 0.0174. Moreover, the average RSE and RMSE value in the ANCOVA models are smaller about 1.24 vol.% and 1.25 vol.% than the ones in the regression model, respectively, which means that the models obtained using ANCOVA more accurately describe the examined relationship.

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Analysis of the Solubility of a Support Filament Made of a Copolymer of Vinyl Alcohol and Butanediol in Aqueous Solutions with Variable pH

88%

Paśnikowska-Łukaszuk M. , Urzędowski A. , Wlazło M. , Mikušová D. , Zaburko J.

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2023

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tom Vol. 24, nr 12

201--207

EN

3D printing is a modern technology that enables the creation of three-dimensional objects from various thermoplastic copolymers. One of the challenges of 3D printing is providing adequate support for complex shapes that may fall apart or deform during the printing process. Traditionally, support materials are used for this purpose, which are difficult to remove after printing and difficult to dispose of. This work focuses on the analysis of the solubility of the BVOH support filament in solutions with different pH values. In particular, the influence of pH on the dissolution time of the BVOH (Butenediol Vinyl Alcohol Co-polymer) copolymer in aqueous solutions and its influence on changes in the PETG base material from which the samples were printed were examined. It was found that the BVOH material combined with PETG is easily soluble in an alkaline environment.