oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 38 )

2018 ( 364 )

2017 ( 372 )

2016 ( 407 )

Custom range...

Search Results: 1 - 10 of 210772 matches for " L. Raczyński "
All listed articles are free for downloading (OA Articles)
Page 1 /210772
Display every page Item
Analysis of Bearing System of Three-Bearing Shafts with Respect to Elastic Shifts in Bearings
Andrzej Raczyński , Jaros aw Kaczor
Archive of Mechanical Engineering , 2010, DOI: 10.2478/v10180-010-0005-z
Abstract: Bearings of three-bearing shafts are usually treated as ideally-rigid articulated supports. In literature, the reactions of supports and bending moments of multibearing shafts are calculated taking into consideration only shaft elasticity. In fact, also deformation is present in these bearings, and it changes the shaft bending line. The deformation thus influences distribution of bending moment and reaction of supports. It is the most important difference when comparing two-bearing with three-bearing shafts. Moreover, in most types of bearings, a reactive bending moment is the response of bearing to unparallel position of inner bearing rings in relation to outer rings, that is to the tilt angle. As a result, real loads of rolling elements differ from theoretical ones. The aim of the paper is to develop a method of calculating generalized loads in rolling bearings of a three-bearing shaft taking into consideration shaft deformation, deformations in bearings and reactive moments of bearings caused by tilt angle.
System Response Kernel Calculation for List-mode Reconstruction in Strip PET Detector
P. Bia?as,J. Kowal,A. Strzelecki,T. Bednarski,E. Czerwiński,?. Kap?on,A. Kochanowski,G. Korcyl,P. Kowalski,T. Kozik,W. Krzemień,M. Molenda,P. Moskal,Sz. Nied?wiecki,M. Pa?ka,M. Pawlik,L. Raczyński,Z. Rudy,P. Salabura,N. G. Sharma,M. Silarski,A. S?omski,J. Smyrski,W. Wi?licki,M. Zieliński
Physics , 2013, DOI: 10.5506/APhysPolBSupp.6.1027
Abstract: Reconstruction of the image in Positron Emission Tomographs (PET) requires the knowledge of the system response kernel which describes the contribution of each pixel (voxel) to each tube of response (TOR). This is especially important in list-mode reconstruction systems, where an efficient analytical approximation of such function is required. In this contribution, we present a derivation of the system response kernel for a novel 2D strip PET.
Application of Compressive Sensing Theory for the Reconstruction of Signals in Plastic Scintillators
L. Raczyński,P. Kowalski,T. Bednarski,P. Bia?as,E. Czerwiński,?. Kap?on,A. Kochanowski,G. Korcyl,J. Kowal,T. Kozik,W. Krzemień,M. Molenda,P. Moskal,Sz. Nied?wiecki,M. Pa?ka,M. Pawlik,Z. Rudy,P. Salabura,N. G. Sharma,M. Silarski,A. S?omski,J. Smyrski,A. Strzelecki,W. Wi?licki,M. Zieliński
Physics , 2013, DOI: 10.5506/APhysPolBSupp.6.1121
Abstract: Compressive Sensing theory says that it is possible to reconstruct a measured signal if an enough sparse representation of this signal exists in comparison to the number of random measurements. This theory was applied to reconstruct signals from measurements of plastic scintillators. Sparse representation of obtained signals was found using SVD transform.
Computing support for advanced medical data analysis and imaging
W. Wi?licki,T. Bednarski,P. Bia?as,E. Czerwiński,?. Kap?on,A. Kochanowski,G. Korcyl,J. Kowal,P. Kowalski,T. Kozik,W. Krzemień,M. Molenda,P. Moskal,S. Nied?wiecki,M. Pa?ka,M. Pawlik,L. Raczyński,Z. Rudy,P. Salabura,N. G. Sharma,M. Silarski,A. S?omski,J. Smyrski,A. Strzelecki,A. Wieczorek,M. Zieliński,N. Zoń
Physics , 2014, DOI: 10.1515/bams-2014-0001
Abstract: We discuss computing issues for data analysis and image reconstruction of PET-TOF medical scanner or other medical scanning devices producing large volumes of data. Service architecture based on the grid and cloud concepts for distributed processing is proposed and critically discussed.
Database and data structure for the novel TOF-PET detector developed for J-PET project
E. Czerwiński,M. Zieliński,T. Bednarski,P. Bia?as,?. Kap?on,A. Kochanowski,G. Korcyl,J. Kowal,P. Kowalski,T. Kozik,W. Krzemień,E. Kubicz,M. Molenda,P. Moskal,Sz. Nied?wiecki,M. Pa?ka,M. Pawlik,L. Raczyński,Z. Rudy,P. Salabura,N. G. Sharma,M. Silarski,A. S?omski,J. Smyrski,A. Strzelecki,A. Wieczorek,W. Wi?licki,N. Zoń
Physics , 2014, DOI: 10.1515/bams-2014-0003
Abstract: The complexity of the hardware and the amount of data collected during the PET imaging process require application of modern methods of efficient data organization and processing. In this article we will discuss the data structures and the flow of collected data from the novel TOF-PET medical scanner which is being developed at the Jagiellonian University. The developed data format reflects: registration process of the gamma quanta emitted from positron-electron annihilation, Front-End Electronic (FEE) structure and required input information for the image reconstruction. In addition, the system database fulfills possible demands of the evolving J-PET project.
A novel method for calibration and monitoring of time synchronization of TOF-PET scanners by means of cosmic rays
M. Silarski,E. Czerwiński,T. Bednarski,P. Moskal,P. Bia?as,?. Kap?on,A. Kochanowski,G. Korcyl,J. Kowal,P. Kowalski,T. Kozik,W. Krzemień,M. Molenda,Sz. Nied?wiecki,M. Pa?ka,M. Pawlik,L. Raczyński,Z. Rudy,P. Salabura,N. G. Sharma,A. S?omski,J. Smyrski,A. Strzelecki,W. Wi?licki,M. Zieliński,N. Zoń
Physics , 2013, DOI: 10.1515/bams-2013-0105
Abstract: All of the present methods for calibration and monitoring of TOF-PET scanner detectors utilize radioactive isotopes such as e.g. $^{22}$Na or $^{68}$Ge, which are placed or rotate inside the scanner. In this article we describe a novel method based on the cosmic rays application to the PET calibration and monitoring methods. The concept allows to overcome many of the drawbacks of the present methods and it is well suited for newly developed TOF-PET scanners with a large longitudinal field of view. The method enables also monitoring of the quality of the scintillator materials and in general allows for the continuous quality assurance of the PET detector performance.
A novel method based solely on FPGA units enabling measurement of time and charge of analog signals in Positron Emission Tomography
M. Pa?ka,T. Bednarski,P. Bia?as,E. Czerwiński,?. Kap?on,A. Kochanowski,G. Korcyl,J. Kowal,P. Kowalski,T. Kozik,W. Krzemień,M. Molenda,P. Moskal,Sz. Nied?wiecki,M. Pawlik,L. Raczyński,Z. Rudy,P. Salabura,N. G. Sharma,M. Silarski,A. S?omski,J. Smyrski,A. Strzelecki,W. Wi?licki,M. Zieliński,N. Zoń
Physics , 2013, DOI: 10.1515/bams-2013-0104
Abstract: This article presents a novel technique for precise measurement of time and charge based solely on FPGA (Field Programmable Gate Array) device and few satellite discrete electronic components used in Positron Emission Tomography (PET). Described approach simplifies electronic circuits, reduces the power consumption, lowers costs, merges front-end electronics with digital electronics and also makes more compact final design. Furthermore, it allows to measure time when analog signals cross a reference voltage at different threshold levels with a very high precision of $\sim$ 10ps (rms) and thus enables sampling of signals in a voltage domain.
Application of WLS strips for position determination in Strip PET tomograph based on plastic scintillators
J. Smyrski,P. Moskal,T. Bednarski,P. Bia?as,E. Czerwiński,?. Kap?on,A. Kochanowski,G. Korcyl,J. Kowal,P. Kowalski,T. Kozik,W. Krzemień,M. Molenda,Sz. Nied?wiecki,M. Pa?ka,M. Pawlik,L. Raczyński,Z. Rudy,P. Salabura,N. G. Sharma,M. Silarski,A. S?omski,A. Strzelecki,W. Wi?licki,M. Zieliński,N. Zoń
Physics , 2013, DOI: 10.1515/bams-2013-0103
Abstract: A method of determination of a gamma quantum absorption point in a plastic scintillator block using a matrix of wavelength-shifting (WLS) strips is proposed. Application of this method for improvement of position resolution in newly proposed PET detectors based on plastic scintillators is presented. The method enables to reduce parallax errors in reconstruction of images which occurs in the presently used Positron Emission Tomography scanners.
J-PET analysis framework for the prototype TOF-PET detector
W. Krzemień,M. Silarski,K. Stola,D. Trybek,T. Bednarski,P. Bia?as,E. Czerwiński,?. Kap?on,A. Kochanowski,G. Korcyl,J. Kowal,P. Kowalski,T. Kozik,M. Molenda,P. Moskal,Sz. Nied?wiecki,M. Pa?ka,M. Pawlik,L. Raczyński,Z. Rudy,P. Salabura,N. G. Sharma,A. S?omski,J. Smyrski,A. Strzelecki,W. Wi?licki,M. Zieliński,N. Zoń
Physics , 2013, DOI: 10.1515/bams-2013-0109
Abstract: Novel TOF-PET scanner solutions demand, apart from the state of the art detectors, software for fast processing of the gathered data, monitoring of the whole scanner and reconstruction of the PET image. In this article we present an analysis framework for the novel STRIP-PET scanner developed by the J-PET collaboration in the Institute of Physics of the Jagiellonian University. This software is based on the ROOT package used in many particle physics experiments.
Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector
D. Kamińska,T. Bednarski,P. Bia?as,E. Czerwiński,A. Gajos,M. Gorgol,B. Jasińska,?. Kap?on,G. Korcyl,P. Kowalski,T. Kozik,W. Krzemień,E. Kubicz,Sz. Nied?wiecki,M. Pa?ka,L. Raczyński,Z. Rudy,O. Rundel,N. G. Sharma,M. Silarski,A. S?omski,A. Strzelecki,A. Wieczorek,W. Wi?licki,M. Zieliński,B. Zgardzińska,P. Moskal
Physics , 2015,
Abstract: In this paper we present prospects for using the J-PET detector to search for discrete symmetries violations in a purely leptonic system of the positronium atom. We discuss tests of CP and CPT symmetries by means of ortho-positronium decays into three photons. No zero expectation values for chosen correlations between ortho-positronium spin and momentum vectors of photons would imply the existence of physics phenomena beyond the Standard Model. Previous measurements resulted in violation amplitude parameters for CP and CPT symmetries consistent with zero, with an uncertainty of about 10-3. The J-PET detector allows to determine those values with better precision thanks to a unique time and angular esolution combined with a high geometrical acceptance. Achieving the aforementioned is possible due to application of polymer scintillators instead of crystals as detectors of annihilation quanta.
Page 1 /210772
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.