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Wyszukujesz frazę "Strzelecki, T." wg kryterium: Autor


Tytuł:
Fatigue life prediction for acid-resistant steel plate under operating loads
Autorzy:
Tomaszewski, T.
Strzelecki, P.
Wachowski, M.
Stopel, M.
Powiązania:
https://bibliotekanauki.pl/articles/200215.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
reliability
macrofractography
finite element analysis
S-N curve
acid-resistant steel
Opis:
The paper evaluates the causes related to the fatigue damage in a conveyor slide plate, exposed to high-frequency cyclic loads. The plate was made of 1.4301 acid-resistant steel. The fractography showed that the plate failure was caused by fatigue crack. A nonlinear analysis of plate deformation was conducted using the finite element method (FEA) in LS-Dyna software. The maximum normal stresses in the plate fracture were used in further analysis. A “fatigue limit” calculated initially using a FITNET procedure was above the maximum stress calculated using FEA. It indicates that the structural features of the plate were selected correctly. The experimental test results for 1.4301 acid-resistant steel were described using a probabilistic Weibull distribution model. Reliability was determined for the obtained S-N curve at 50% and 5% failure probability allowing for the selected coefficients (cycle asymmetry, roughness, variable load) and the history of cyclic loading. Cumulative damage was determined using the Palmgren-Miner hypothesis. The estimated fatigue life was similar to the actual value determined in the operating conditions for the S-N curve at 5% failure probability. For engineering calculations, the S-N curve at max. 5% failure probability is recommended.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 4; 913-921
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of genetic algorithms for the estimation of hydraulic conductivity
Autorzy:
Bartlewska-Urban, M.
Strzelecki, T.
Powiązania:
https://bibliotekanauki.pl/articles/178471.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
genetic algorithms
hydraulic conductivity
Biot consolidation model
Opis:
In the study described here model calibration was performed employing the inverse analysis using genetic algorithms (GA). The objective of analysis is to determine value of the coefficient of hydraulic conductivity, k. The commonly used method for the determination of coefficient of hydraulic conductivity based on Terzaghi consolidation leads to an underestimation of the value of k as the Terzaghi model does not take into account the deformation of soil skeleton. Here, an alternative methodology based on genetic algorithms is presented for the determination of the basic parameters of Biot consolidation model. It has been demonstrated that genetic algorithms are a highly effective tool enabling automatic calibration based on simple rules. The values of the coefficient of hydraulic conductivity obtained with GA are of at least one order smaller than values obtained with the Terzaghi model.
Źródło:
Studia Geotechnica et Mechanica; 2018, 40, 2; 140-146
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical 3D simulations of seepage and the seepage stability of the right-bank dam of the Dry Flood Control Reservoir in Racibórz
Autorzy:
Strzelecki, T.
Uciechowska-Grakowicz, A.
Strzelecki, M.
Sawicki, E.
Maniecki, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/178251.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
seepage
3D simulation
anisotropy
gravel columns
Opis:
This article presents the results of numerical simulations of seepage through the body of the dam and the reservoir bed. The purpose of this study was to analyse the seepage stability during a flood as well as the impact on seepage stability of the diaphragm wall and gravel columns, on which the dam body is founded in selected segments. Simulations were conducted for three different locations, and the following 3D models of the dum were prepared: – a model containing the front and right-bank part of the dam, for which no diaphragm wall, gravel columns and drainage ditch were provided for – a model of a segment of the right-bank dam including a diaphragm wall, drainage ditch and gravel columns under the dam (two variants with differing diaphragm wall lengths) – a model of the water dam segment accounting for gravel columns and a drainage ditch, but without a diaphragm wall. In the case of founding on gravel columns, the base was modelled as an anisotropic medium in terms of seepage properties, macroscopically equivalent to the actual soil medium. The numerical model utilises the finite element method. The geometry of the dam and geological substrate was defined in the GIS tools in the form of a 3D model of the terrain and geology of the substrate.
Źródło:
Studia Geotechnica et Mechanica; 2018, 40, 1; 11-20
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of selected mathematical models of high-cycle S-N characteristics
Autorzy:
Strzelecki, P.
Sempruch, J.
Tomaszewski, T.
Powiązania:
https://bibliotekanauki.pl/articles/298416.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
high-cycle fatigue
S-N curve
fatigue tests
number of specimen
steel strength
Opis:
The paper presents two approaches of determining S-N fatigue characteristics. The first is a commonly used and well-documented approach based on the least squares method and staircase method for limited fatigue life and fatigue limit, accordingly. The other approach employs the maximum likelihood method. The analysis of the parameters obtained through both approaches exhibited minor differences. The analysis was performed for four steel construction materials, i.e. C45+C, 45, SUS630 and AISI 1045. It should be noted that the quantity of samples required in the second approach is significantly smaller than with the first approach, which translates into lower duration and costs of tests.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2017, 20(3); 227-240
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-isothermal constitutive relations and heat transfer equations of a two-phase medium
Autorzy:
Uciechowska-Grakowicz, A.
Strzelecki, T.
Powiązania:
https://bibliotekanauki.pl/articles/178714.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
heat transfer
porous media
thermal consolidation
constitutive equations
Opis:
In the case of a two-phase medium – such as the soil, which consists of an elastic skeleton and is filled with pore fluids – stress and strain within the medium are dependent on both phases. Similarly, in the case of heat transfer, heat is conducted through the two phases at different rates, with an additional heat transfer between the phases. In the classical approach to modelling a porous medium, it is assumed that the fluid filling the pore space is water, which is incompressible. In the case of gas, the volume of which is strongly dependent on temperature and pressure, one should take this behavior into account in the constitutive relations for the medium. This work defines the physical relations of a two-phase medium and provides heat transfer equations, constructed for a porous, elastic skeleton with fluid-filled pores, which may be: liquid, gas, or mixture of liquid and a gas in non-isothermal conditions. The paper will present constitutive relations derived from the laws of irreversible thermodynamics, assuming that pores are filled with either a liquid or a gas. These relations, in the opinion of the authors, may be used as the basis for the construction of a model of the medium filled partly with a liquid and partly with a gas. It includes the possibility of independent heat transfer through any given two-phase medium phase, with the transfer of heat between the phases.
Źródło:
Studia Geotechnica et Mechanica; 2017, 39, 3; 67-78
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary studies of J-PET detector spatial resolution
Autorzy:
Pawlik-Niedźwiecka, M.
Niedźwiecki, S.
Alfs, D.
Białas, P.
Curceanu, C.
Czerwiński, E.
Dulski, K.
Gajos, A.
Głowacz, B.
Gorgol, M.
Hiesmayr, B.
Jasińska, B.
Kisielewska, D.
Korcyl, G.
Kowalski, P.
Kozik, T.
Krawczyk, N.
Krzemień, W.
Kubicz, E.
Mohammed, M.
Pałka, M.
Raczyński, L.
Raj, J.
Rudy, Z.
Shivani, -
Silarski, M.
Skurzok, M.
Sharma, N.
Sharma, S.
Shopa, R.
Strzelecki, A.
Wieczorek, A.
Wiślicki, W.
Zgardzińska, B.
Zieliński, M.
Moskal, P.
Powiązania:
https://bibliotekanauki.pl/articles/1057928.pdf
Data publikacji:
2017-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
29.40.Mc
87.57.uk
87.10.Rt
34.50.-s
Opis:
The J-PET detector, based on long plastic scintillator strips, was recently constructed at the Jagiellonian University. It consists of 192 modules axially arranged into three layers, read out from both sides by digital constant-threshold front-end electronics. This work presents preliminary results of measurements of the spatial resolution of the J-PET tomograph performed with ²²Na source placed at selected position inside the detector chamber.
Źródło:
Acta Physica Polonica A; 2017, 132, 5; 1645-1648
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument
Autorzy:
Raczyński, L.
Moskal, P.
Kowalski, P.
Wiślicki, W.
Bednarski, T.
Białas, P.
Czerwiński, E.
Gajos, A.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowal, J.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, S.
Pałka, M.
Rudy, Z.
Salabura, P.
Gupta-Sharma, N.
Silarski, M.
Słomski, A.
Smyrski, J.
Strzelecki, A.
Wieczorek, A.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/146280.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
compressed sensing
positron emission tomography
time-of-flight
Opis:
Nowadays, in positron emission tomography (PET) systems, a time of fl ight (TOF) information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten signifi cantly a range along the line-of-response (LOR) where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS) theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta.
Źródło:
Nukleonika; 2016, 61, 1; 35-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical model of heat transfer in three phases of the poroelastic medium
Autorzy:
Uciechowska-Grakowicz, A.
Strzelecki, T.
Powiązania:
https://bibliotekanauki.pl/articles/178519.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
poroelasticity
Biot model
thermal consolidation
GAS
Opis:
In this paper, the results of numerical analysis of the thermal consolidation of a two phase medium, under the assumption of independent heat transfer in fluid and the solid phase of the medium, are presented. Three cases of pore fluid were considered: liquid, represented by water, and gas, represented by air and carbon dioxide. The mathematical model was derived from irreversible thermodynamics, with the assumption of a constant heat transfer between the phases. In the case of the accepted geometry of the classical dimensions of the soil sample and boundary conditions, the process leads to equalization of temperatures of the skeleton on the pore fluid. Heat transfer is associated with the fluid flow in the pores of the medium. In the case of gas as the pore fluid, a non-linear mathematical model of gas filtration through the pores of the medium was accepted. For the computing process, relationships between viscosity or density and temperature proposed by other authors were taken into account. Despite accepting mechanical constants of the solid phase that do not depend on temperature, the obtained model is nonlinear and develops the classical Biot–Darcy model.
Źródło:
Studia Geotechnica et Mechanica; 2016, 38, 2; 53-59
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Pilot Study of the Novel J-PET Plastic Scintillator with 2-(4-styrylphenyl)benzoxazole as a Wavelength Shifter
Autorzy:
Wieczorek, A.
Moskal, P.
Niedźwiecki, S.
Bednarski, T.
Białas, P.
Czerwiński, E.
Danel, A.
Gajos, A.
Gruntowski, A.
Kamińska, D.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowal, J.
Kowalski, P.
Kozik, T.
Krzemień, W.
Kubicz, E.
Molenda, M.
Pałka, M.
Raczyński, L.
Rudy, Z.
Rundel, O.
Salabura, P.
Sharma, N.
Silarski, M.
Słomski, A.
Smyrski, J.
Strzelecki, A.
Uchacz, T.
Wiślicki, W.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/1402620.pdf
Data publikacji:
2015-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.57.uk
29.40.Mc
Opis:
For the first time a molecule of 2-(4-styrylphenyl)benzoxazole containing benzoxazole and stilbene groups is applied as a scintillator dopant acting as a wavelength shifter. In this article a light yield of the plastic scintillator, prepared from styrene doped with 2 wt% of 2,5-diphenylbenzoxazole and 0.03 wt% of 2-(4-styrylphenyl)benzoxazole, is determined to be as large as 60% ± 2% of the anthracene light output. There is a potential to improve this value in the future by the optimization of the additives concentrations.
Źródło:
Acta Physica Polonica A; 2015, 127, 5; 1487-1490
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis Framework for the J-PET Scanner
Autorzy:
Krzemień, W.
Gajos, A.
Gruntowski, A.
Stola, K.
Trybek, D.
Bednarski, T.
Białas, P.
Czerwiński, E.
Kamińska, D.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowal, J.
Kowalski, P.
Kozik, T.
Kubicz, E.
Moskal, P.
Niedźwiecki, Sz.
Pałka, M.
Raczyński, L.
Rudy, Z.
Salabura, P.
Sharma, N.
Silarski, M.
Słomski, A.
Smyrski, J.
Strzelecki, A.
Wieczorek, A.
Wiślicki, W.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/1402621.pdf
Data publikacji:
2015-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.57.nf
87.57.uk
29.85.-c
Opis:
J-PET analysis framework is a flexible, lightweight, ROOT-based software package which provides the tools to develop reconstruction and calibration procedures for PET tomography. In this article we present the implementation of the full data-processing chain in the J-PET framework which is used for the data analysis of the J-PET tomography scanner. The framework incorporates automated handling of PET setup parameters' database as well as high level tools for building data reconstruction procedures. Each of these components is briefly discussed.
Źródło:
Acta Physica Polonica A; 2015, 127, 5; 1491-1494
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the foundation slab settlement of the “Africa Pavilion” facility in Wrocław
Autorzy:
Sawicki, E.
Strzelecki, T.
Powiązania:
https://bibliotekanauki.pl/articles/178401.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
soil consolidation
numerical calculations
settlement
hydraulic conduits
Opis:
This article presents the results of numerical calculations of soil consolidation underneath the “Africa Pavilion” structure in Wrocław Zoo, Poland. To determine the deformations of the baseplate of the “Africa Pavilion” and deformations of the subsoil, Biot’s consolidation theory for two-phase medium was applied. The calculations were carried out using the professional program FlexPDE v.6, which is based on the Finite Element Method. Numerical calculations performed were used to evaluate the design assumptions allowing for the laying of hydraulic conduits under the slab.
Źródło:
Studia Geotechnica et Mechanica; 2015, 37, 4; 47-55
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Building a numerical model of the filtration flow in the “Żelazny Most” flotation tailings disposal lake
Autorzy:
Strzelecki, T.
Maniecki, Ł.
Bartlewska-Urban, M.
Powiązania:
https://bibliotekanauki.pl/articles/178495.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
filtration flow
three-dimensional numerical models
flotation wastes
tailings disposal lake
Opis:
The paper presents results of numerical computations of the filtration flow of liquid contaminated wastes through the Żelazny Most flotation tailings disposal lake. Unlike the preceding papers [5]–[7], it takes the geological structure of the subsoil into account. A three-dimensional numerical model of the lake was created for computing purposes. Data on some of the effective model parameters were acquired from laboratory tests of the material taken from the lake site. The other data were taken from the literature for media of similar properties. The results of the computations carried out using the model can be a basis for future numerical analyses aimed at determining the consolidation of the flotation tailings disposal lake and its subsoil, and the stability of the lake.
Źródło:
Studia Geotechnica et Mechanica; 2015, 37, 1; 93-104
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GPU Accelerated Image Reconstruction in a Two-Strip J-PET Tomograph
Autorzy:
Białas, P.
Kowal, J.
Strzelecki, A.
Bednarski, T.
Czerwiński, E.
Gajos, A.
Kamińska, D.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowalski, P.
Kozik, T.
Krzemień, W.
Kubicz, E.
Moskal, P.
Niedźwiecki, Sz.
Pałka, M.
Raczyński, L.
Rudy, Z.
Rundel, O.
Salabura, P.
Sharma, N.
Silarski, M.
Słomski, A.
Smyrski, J.
Wieczorek, A.
Wiślicki, W.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/1402623.pdf
Data publikacji:
2015-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.57.nf
87.57.uk
Opis:
We present a fast GPU implementation of the image reconstruction routine, for a novel two strip PET detector that relies solely on the time of flight measurements.
Źródło:
Acta Physica Polonica A; 2015, 127, 5; 1500-1504
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hit Time and Hit Position Reconstruction in the J-PET Detector Based on a Library of Averaged Model Signals
Autorzy:
Moskal, P.
Sharma, N.
Silarski, M.
Bednarski, T.
Białas, P.
Bułka, J.
Czerwiński, E.
Gajos, A.
Kamińska, D.
Kapłon, L.
Kochanowski, A.
Korcyl, G.
Kowal, J.
Kowalski, P.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, Sz.
Pałka, M.
Raczyński, L.
Rudy, Z.
Rundel, O.
Salabura, P.
Słomski, A.
Smyrski, J.
Strzelecki, A.
Wieczorek, A.
Wiślicki, W.
Wochlik, I.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/1402622.pdf
Data publikacji:
2015-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.57.uk
07.05.Kf
Opis:
In this article we present a novel method of hit time and hit position reconstruction in long scintillator detectors. We take advantage of the fact that for this kind of detectors amplitude and shape of registered signals depend strongly on the position where particle hits the detector. The reconstruction is based on determination of the degree of similarity between measured and averaged signals stored in a library for a set of well-defined positions along the scintillator. Preliminary results of validation of the introduced method with experimental data obtained by means of the double strip prototype of the J-PET detector are presented.
Źródło:
Acta Physica Polonica A; 2015, 127, 5; 1495-1499
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multiple Scattering and Accidental Coincidences in the J-PET Detector Simulated Using GATE Package
Autorzy:
Kowalski, P.
Moskal, P.
Wiślicki, W.
Raczyński, L.
Bednarski, T.
Białas, P.
Bułka, J.
Czerwiński, E.
Gajos, A.
Gruntowski, A.
Kamińska, D.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowal, J.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, Sz.
Pałka, M.
Rudy, Z.
Salabura, P.
Sharma, N.
Silarski, M.
Słomski, A.
Smyrski, J.
Strzelecki, A.
Wieczorek, A.
Wochlik, I.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/1402625.pdf
Data publikacji:
2015-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
29.40.Mc
87.57.uk
87.10.Rt
34.50.-s
Opis:
Novel positron emission tomography system, based on plastic scintillators, is developed by the J-PET collaboration. In order to optimize geometrical configuration of built device, advanced computer simulations are performed. Detailed study is presented of background given by accidental coincidences and multiple scattering of gamma quanta.
Źródło:
Acta Physica Polonica A; 2015, 127, 5; 1505-1512
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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