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This work presents basic information associated with markets of selected alternative fuels used in transport, such as methyl esters, conventional bioethanol and lignocellulosic bioethanol, and the market of electrical vehicles. Legal conditions, which stimulate development and regulate the mode of functioning of the liquid biofuel market until 2020 are discussed, based on provisions of EU directives. Data on biofuel production in Poland are presented, as well as biofuel consumption in the EU, the USA and Brazil in 2017. The most important conclusions of the proposal for a directive on the promotion of renewable energy sources in transport in EU member states in years 2021–2030 are discussed. The authors have also indicated the key legal and territorial conditions associated with the development of electromobility and present basic information on electric vehicles in Poland and Europe. The results of the research on the attractiveness of these sectors in 2018 are presented and compared with the results obtained in years 2007–2017. A score-based sector attractiveness method was used in the research.
2019
Adam Kupczyk,
Joanna Mączyńska,
Grzegorz Redlarski,
Karol Tucki,
Anna Bączyk,
Dominik Rutkowski
This paper presents results of investigations on a three-dimensional (3-D) isotropic periodic beam. The beam can represent a vibroacoustic isolator of optimised dynamic characteristics in the case of its longitudinal, flexural and torsional behaviour. The optimisation process concerned both the widths as well as the positions of particular frequency band gaps that are present in the frequency spectrum of the beam. Since the dynamic behaviour of the beam is directly related to its geometry, through an optimisation process of the beam geometry, desired dynamic characteristics of the beam were successfully obtained. For the purpose of the optimisation process a new numerical model of the beam, based on the spectral finite element method in the time domain (TD-SFEM), was developed by the authors. This model enabled the authors to investigate the beam behaviour not only in a wide frequency spectrum, but also ensured a high accuracy of the model predictions. The accuracy of this modelling approach was checked against well-known analytical formulas. However, in the case of the optimised geometry of the beam for the verification of the correctness of the modelling approach a commercial finite element method (FEM) package was used. Finally, based on the results of numerical predictions and optimised geometry of the beam a sample for experimental verification was prepared.Experimental measurements were carried out by the authors by the application of one-dimensional (1-D) laser Doppler scanning vibrometry (LDSV). The results of experimental measurements obtained by the authors confirmed the correctness of the numerical predictions, showing a high degree of correspondence.
2019
Arkadiusz Żak,
Marek Krawczuk,
Grzegorz Redlarski,
Łukasz Doliński,
Slawomir Koziel
This paper deals with certain aspects related to the dynamic behaviour of isotropic shell-like structures analysed by the use of a higher order transversely deformable shell-type spectral finite element newly formulated and the approach known as the Time-domain Spectral Finite Element Method (TD-SFEM). Although recently this spectral approach is reported in the literature as a very powerful numerical tool used to solve various wave propagation problems, its properties make it also very well suited to solve static and dynamic modal problems. The robustness and effectiveness of the current spectral approach has been successfully demonstrated by the authors in the case of thin-walled spherical shell structures through a series of numerical tests comprising the analysis of natural frequencies and modes of vibration of an isotropic spherical shell as well as the wave propagation analysis in the case of the same spherical shell and a half-pipe shell-like structure.
2018
Arkadiusz Żak,
Marek Krawczuk
This paper demonstrates the effectiveness of a nondestructive diagnostic technique used to determine the location and size of delamination in laminated coatings of wind turbine blades. This is realized based on results of numerical and experimental investigations obtained by the use of the finite element method (FEM) and laser scanning vibrometry (LSV). The proposed method is based on the one-dimensional continuous wavelet transform of vibration parameters of a wind turbine blade. The investigations were conducted for a 1 : 10 scaled-down blade of a 36m rotor wind turbine. Glass fibres and epoxy resin were used as laminate components. For numerical studies, a simple delamination model was proposed. The results obtained by the authors were used to determine the optimal set of parameters of the continuous wavelet transform.The application of high-quality LSV for experimental measurements allowed determining the optimal conditions of measuring procedures.At the same time the capabilities and limitations, resulting from the nature of the measurement method, were identified. In order to maximize the effectiveness of the detection method, preliminary signal processing was performed. Beside base wavelets also different waveform families were tested.The results obtained by the authors showed that it is possible to identify and localize even relatively small damage.
2018
Łukasz Doliński,
Marek Krawczuk,
Arkadiusz Żak
Currently used body surface area (BSA) formulas give satisfactory results only for individuals with typical physique, while for elderly, obese or anorectic people accurate results cannot be expected. Particularly noteworthy are the results for individuals with severe obesity (body-mass index greater than 35 kg/m2), for which BSA estimation errors reached 80%. The main goal of our study is the development of precise BSA models for specific body parts. We have achieved satisfactory results for a wide range of patients. Using regression models, such as: support vector regression, multilayer perceptron regressor, stochastic gradient descent, or ridge regression, a fourfold decrease in errors proportion is achieved. Machine learning algorithms led to reduction from 1.2 to 8 times for mean estimation error.
2018
Gustaw Rzyman,
Grzegorz Redlarski,
Aleksander Pałkowski,
Piotr Tojza,
Marek Krawczuk,
Janusz Siebert
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