Wyniki wyszukiwania - Biblioteka Nauki

1

Modeling of the crystalline structure of the complex system containing doped polyaniline by use of genetic algorithms

100%

Kozik T. , Luzny W.

Journal of Education and Technical Sciences

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2015

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tom Vol. 2, nr 1

9--14

EN

The structure of polyaniline (PANI) protonated with camphorsulphonic acid (CSA) has been subject to research for a long time. Despite several, various models being proposed throughout the years, there is still no model widely accepted as the only correct and final one of its crystalline phase. In this paper a computer program named MoleculeEditor is described. Created basing on the concepts of an existing but significantly different program named CrystalFinder, it is a software dedicated to finding a model of the crystalline regions of the PANI/CSA system based on an input X-ray diffraction pattern. In its search it takes advantage of the genetic algorithm technique for optimizing the model parameters to fit the computed diffraction pattern to the one loaded as input. A successful example of it being employed to find the parameters of a prepared beforehand, fictional structure of the system, is presented. Conclusions drawn from this application of the prepared software cannot be ignored in the further search for the actual model of this complex system using this program. Obtaining results from MoleculeEditor for actual, experimental data is however still in progress.

2

Effect of solvents on structural anisotropy of polyaniline thin films

80%

Śniechowski M. , Kozik T. , Łużny W.

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2017

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tom T. 62, nr 11-12

855--860

EN

X-ray surface diffraction experiments performed on polyaniline/camphorsulfonic acid (PANI/CSA) thin films reveal high anisotropy of the five main crystalline peaks. This anisotropy is different for samples cast from m-cresol and cast from trifluoroacetic acid (TFA). Taking advantage of a recently published crystalline unit cell model, intensity distribution maps are calculated for these two types of samples. The anisotropy is in agreement with experiment, further validating the PANI/CSA model and showing that solvent molecules are not present in the unit cell.

PL

Cienkowarstwowe, wykazujące silną anizotropię próbki polianilina/kwas kamforosulfonowy (PANI/CSA) zbadano metodą dyfrakcji powierzchniowej promieniowania rentgenowskiego. Wyniki pomiarów w geometriach: transmisyjnej, odbiciowej i pośrednich wykazały różnice między natężeniami pięciu głównych maksimów krystalicznych. Anizotropia próbek była różna w wypadku użycia różnych rozpuszczalników (m-cresol, kwas trifluorooctowy). Niedawno opublikowany model struktury PANI/CSA wykorzystano do obliczenia map natężeń, a następnie do porównań z wynikami pomiarów. Proponowany model poprawnie opisuje uporządkowanie w próbkach folii z PANI/CSA wylanych z różnych rozpuszczalników, bez konieczności uwzględniania w nim cząsteczek rozpuszczalnika. Świadczy to o tym, że cząsteczki rozpuszczalnika nie występują w strukturze PANI/CSA jako składniki komórki elementarnej.

3

Rekonstrukcja kół zębatych z zastosowaniem systemów CMM/CAD/RP

80%

Budzik G. , Dziubek T. , Kozik T. , Zaborniak M.

Mechanik

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2015

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tom R. 88, nr 12CD2

18--21

PL

W artykule przedstawiono metodykę rekonstrukcji kół zębatych przekładni lotniczych z zastosowaniem powiązanych systemów CMM/CAD/RP. Współrzędnościowe techniki pomiarowe (CMM) oraz systemy CAD umożliwia identyfikację i odtwarzanie geometrii kół zębatych, natomiast systemy RP dają możliwość wykonania prototypu zrekonstruowanego koła zębatego.

EN

This paper presents a reconstruction methodology of the transmission airline gears connected systems using CMM/CAD/RP. The use of coordinate measuring techniques (CMMs) and CAD systems enables to identify and reconstruct gear geometry. In contrast, while the RP systems make it possible to create a prototype with the reconstructed gear.

4

Elektroda interkalacyjna w ogniwie litowym z niewodnym roztworem elektrolitu. [Cz.] 1. Dwutlenek manganu i tlenki litowo-manganowe

80%

Bełtowska-Brzezińska M. , Kozik T. , Jaworska H.

Wiadomości Chemiczne

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2001

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tom [Z] 55, 3-4

289--329

EN

Lithium batteries of various types have found use in portable electronic devices and are also considered for application in electric or hybrid vehicles because of their high operating voltage and energy density. Among a number of materials examined as the positive electrode in lithium batteries with organic electrolyte solution, much attention has been paid to transition metal oxides, in particular to manganese dioxide and its lithiated derivatives. Electrochemical studies have proved that these compounds are able to accommodate or remove Li+ ions in parallel with the electron injection or extraction thus changing the oxidation state of manganese (IV/III) upon the solid state redox reaction. The capacity and power density of intercalation electrodes varies with the crystallographic and electronic structure of their solid phase, electrode thickness and porosity as well as the chemical nature and conductivity of the electrolyte solution. The kinetics of the electrochemical intercalation-deintercalation of Li+ ions is mostly limited by the diffusion of these ions into or from the host matrix. Another limitation comes from an electrolyte depletion in pores of the electrode material during the discharge, as the rate of the Li+ ions transport from the bulk electrolyte is lower in comparison with the charge transfer rate at the electrode/electrolyte interface. The diffusion model for nonporous and porous intercalation electrodes quite well describes the surface and bulk distribution of Li+ ions in the solid phase as well as in the pore electrolyte, as a function of the discharge rate and discharge degree. The experimental characteristics of MnO2 and compounds of the Li-Mn-O system, obtained at various electrode thickness, particle size and charge-discharge density has confirmed the theoretical predictions. Manganese dioxide (g-MnO2) electrodes having discharge capacity of 220-270 Ah/kg at Eť3 V vs. Li/Li+ show a limited rechargeability on charge-discharge cycling in secondary lithium cells. As evidenced by XRD-ray patterns this is due to anisotropic expansion and contraction of the crystallographic unit cell at the average manganese valence of about +3.5. A significantly higher cycling efficiency can be achieved with MnO2(CDMO) and Li-Mn-O spinel phases, providing a three-dimensional interstitial space for Li+ ions transport. The cubic close-packed structure of the stoichiometric LiMn2O4 remains almost unchanged upon deintercalation to l-MnO2 and subsequent reintercalation to x ť 1 in the potential range E ť 4 V (vs. Li/Li+). One can obtain the rechargeable capacity of 125 Ah/kg at moderate current rates owing to the relatively fast solid state diffusion of Li+ ions for 0< x <1. Two further potential plateau's at E ť 3 V and E ť 1 V correspond to the intercalation degree of 1< x <2 and 2< x <4 upon a cubic-tetragonal and tetragonal-trygonal phase transition, respectively. The identification of three distinct regions in the potential-composition (E-x) curves at makes the basis for spinel electrodes application in energy storage devices. In the last years, several overlithiated and defect spinel phases of the general formula (...) have been used in the so-called "lithium-ion" batteries with the carbon based negative electrode. Alternative lihium-ion batteries contain two transition metal oxides having different intercalation potentials. Quite recently, a family of mixed spinel oxides Li (...) has been proposed for the positive electrode, Li[Li0,33Ti1,67]O4 as the negative electrode. Future improvement of the charge-discharge performance of spinel electrodes for primary and secondary lithium batteries can be expected under a complex optimisation of the synthesis methods, the electrode mophology, porosity and thickness. Furthermore, the advanced batteries require the high conductivity electrolyte-solvent systems, stable in the potential range of at least 0 to 5V.

5

Challenge and adventure: twenty years of searching for the model structure of the polyaniline/camphorsulfonic acid conducting polymer system leading to an artificial intelligence approach

80%

Kozik T. , Śniechowski M. , Łużny W.

|

2017

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tom T. 62, nr 11-12

800--805

EN

The search for the model structure of polyaniline/camphorsulfonic acid (PANI/CSA) began approximately twenty years ago and remained an unsolved problem. Recently, a new molecular dynamics based model was published in which the system forms a structure of alternating double layers. Having brought together all available information regarding the system, an artificial intelligence approach was formulated, which resulted in finding a model of the crystalline regions of the polymer system in agreement with various experimental results. The approach is thoroughly described due to its versatility.

PL

Poszukiwania modelu struktury systemu polianilina/kwas kamforosulfonowy (PANI/CSA) rozpoczęły się przed ok. dwudziestu laty, nadal jednak problem pozostaje nierozwiązany. W minionych latach opublikowano nowy model otrzymany w wyniku symulacji metodą dynamiki molekularnej. Zgodnie z jego przewidywaniami w systemie PANI/CSA powstaje struktura naprzemiennych dwuwarstw. Na podstawie dostępnej wiedzy sformułowano wykorzystującą algorytmy sztucznej inteligencji metodę, która doprowadziła do znalezienia modelu wykazującego zgodność z różnego rodzaju doświadczeniami. Ze względu na uniwersalność opracowanej metody, szczegółowo ją opisano.

6

Fragmentation and Skeletal Rearrangements of the Protonated Spiro(2H-benzimidazole-2-4'-pyrazole)-5'-one Dyes Studied by Electrospray Ionization and Liqiud Secondary Iohn Mass Spectrometry

71%

Frański R. , Kozik T. , Schroeder G. , Kucybała Z. , Pączkowski J.

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2003

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tom Vol. 77 / nr 10

1301-1312

EN

The mass spectrometric decomposition of the titled compounds was studied by using electrospray ionization (ESI) and liquid secondary ion mass spectrometry (LSIMS) as a methods for [M+H]+ ions generation. Low-energy collision induced dissociation (fragmentation "in source") mass spectra for ESI and B/E linked scan mass spectra of metastable ions for LSIMS were performed. In order to better understand the decomposition of the compounds studied, the mass spectra of isotopically labelled compounds were recorded. The fragmentation pathways of [M+H]+ ions were found to be complex and skeletal rearrangements were observed. It was deduced that subsequent loss of NH3 and H2O molecules leads to the formation of ions with polycyclic structures. The fragment ion [133]+ and its complementary fragment ion [M+H-132]+ can be considered as protonated molecules of 3-methyl-1H-indazole and 2-hydroxyquinoxaline, respectively. Loss of the CH3CN molecule also occurs and this is rather simply process. Aniline elimination (H2N-C6H5) and formation of ions at m/z 146 are complex processes and it was difficult

7

Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument

31%

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.

Nukleonika

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2016

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tom Vol. 61, No. 1

35--39

EN

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.

8

Application of WLS strips for position determination in strip PET tomograph based on plastic scintillators

31%

Smyrski J. , Moskal P. , Bednarski T. , Białas P. , Czerwiński E. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Molenda M. , Niedźwiecki S. , Pałka M. , Pawlik-Niedźwiecka M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Silarski M. , Słomski A. , Strzelecki A. , Wiślicki W. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 2

59--63

EN

A method of the determination of a γ-quantum absorption point in a plastic scintillator block using a matrix of wavelength-shifting (WLS) strips is proposed. An application of this method for the improvement of position resolution in newly proposed positron emission tomography (PET) detectors based on plastic scintillators is presented. The method enables to reduce parallax errors in the reconstruction of images, which occurs in the presently used PET scanners.

9

A novel method for calibration and monitoring of time synchronization of TOF-PET scanners by means of cosmic rays

31%

Silarski M. , Czerwiński E. , Bednarski T. , Moskal P. , Białas P. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Molenda M. , Niedźwiecki S. , Pałka M. , Pawlik M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Słomski A. , Smyrski J. , Strzelecki A. , Wiślicki W. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 1

19--25

EN

All of the present methods for calibration and monitoring of time-of-flight positron emission tomography (TOF-PET) scanner detectors utilize radioactive isotopes, such as 22Na or 68Ge, 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 the monitoring of the quality of the scintillator materials and in general allows for the continuous quality assurance of the PET detector performance.

10

Computing support for advanced medical data analysis and imaging

31%

Wiślicki W. , Bednarski T. , Białas P. , Czerwiński E. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Molenda M. , Moskal P. , Niedźwiecki S. , Pałka M. , Pawlik-Niedźwiecka M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Silarski M. , Słomski A. , Smyrski J. , Strzelecki A. , Wieczorek A. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 2

53--58

EN

We discuss computing issues for data analysis and image reconstruction of positron emission tomography based on time-of-flight medical scanner or other medical scanning devices producing large volumes of data. Service architecture based on grid and cloud concepts for distributed processing is proposed and critically discussed.

11

Plastic scintillators for positron emission tomography obtained by the bulk polymerization method

31%

Kapłon Ł. , Kochanowski A. , Molenda M. , Moskal P. , Wieczorek A. , Bednarski T. , Białas P. , Czerwiński E. , Korcyl G. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Niedźwiecki S. , Pałka M. , Pawlik M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Silarski M. , Słomski A. , Smyrski J. , Strzelecki A. , Wiślicki W. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 1

27--31

EN

This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillators, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.

12

3D PET image reconstruction based on the maximum likelihood estimation method (MLEM) algorithm

31%

Słomski A. , Rudy Z. , Bednarski T. , Białas P. , Czerwiński E. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Molenda M. , Moskal P. , Niedźwiecki S. , Pałka M. , Pawlik M. , Raczyński L. , Salabura P. , Gupta-Sharma N. , Silarski M. , Smyrski J. , Strzelecki A. , Wiślicki W. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 1

1--7

EN

A positron emission tomography (PET) scan does not measure an image directly. Instead, a PET scan measures a sinogram at the boundary of the field-of-view that consists of measurements of the sums of all the counts along the lines connecting the two detectors. Because there is a multitude of detectors built in a typical PET structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Significant improvement in PET image quality was achieved with the introduction of iterative reconstruction techniques. This was realized approximately 20 years ago (with the advent of new powerful computing processors). However, three-dimensional imaging still remains a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines of response and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.

13

PALS investigations of free volumes thermal expansion of J-PET plastic scintillator synthesized in polystyrene matrix

31%

Wieczorek A. , Zgardzińska B. , Jasińska B. , Gorgol M. , Bednarski T. , Białas P. , Czerwiński E. , Gajos A. , Kamińska D. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowalski P. , Kozik T. , Krzemień W. , Kubicz E. , Niedźwiecki S. , Pałka M. , Raczyński L. , Rudy Z. , Rundel O. , Sharma N. G. , Silarski M. , Silarski A. , Strzelecki A. , Wiślicki W. , Zieliński M. , Moskal P.

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tom Vol. 60, No. 4, part 1

777--781

EN

The polystyrene doped with 2,5-diphenyloxazole as a primary fluor and 2-(4-styrylphenyl)benzoxazole as a wavelength shifter prepared as a plastic scintillator was investigated using positronium probe in wide range of temperatures from 123 to 423 K. Three structural transitions at 260, 283, and 370 K were found in the material. In the o-Ps intensity dependence on temperature, the significant hysteresis is observed. Heated to 370 K, the material exhibits the o-Ps intensity variations in time.

14

Trigger-less and reconfigurable data acquisition system for positron emission tomography

31%

Korcyl G. , Moskal P. , Bednarski T. , Białas P. , Czerwiński E. , Kapłon Ł. , Kochanowski A. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Molenda M. , Niedźwiecki S. , Pałka M. , Pawlik M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Silarski M. , Słomski A. , Smyrski J. , Strzelecki A. , Wiślicki W. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 1

37--40

EN

This article is focused on data acquisition system (DAQ) designed especially to be used in positron emission tomography (PET) or single-photon emission computed tomography. The system allows for continuous registration of analog signals during measurement. It has been designed to optimize registration and processing of the information carried by signals from the detector system in PET scanner. The processing does not require any rejection of data with a trigger system. The proposed system possesses also an ability to implement various data analysis algorithms that can be performed in real time during data collection.

15

Database and data structure for the novel TOF-PET detector developed for the J-PET project

31%

Czerwiński E. , Zieliński M. , Bednarski T. , Białas P. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Kubicz E. , Molenda M. , Moskal P. , Niedźwiecki S. , Pałka M. , Pawlik-Niedźwiecka M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Silarski M. , Słomski A. , Smyrski J. , Strzelecki A. , Wieczorek A. , Wiślicki W. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 2

79--83

EN

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 that is being developed at the Jagiellonian University. The developed data format reflects the registration process of the γ quanta emitted from positron electron annihilation, front-end electronic structure, and required input information for the image reconstruction. In addition, the system database fulfills possible demands of the evolving J-PET project.

16

Reconstruction of hit time and hit position of annihilation quanta in the J-PET detector using the Mahalanobis distance

31%

Sharma N. G. , Silarski M. , Bednarski T. , Białas P. , Czerwiński E. , Gajos A. , Gorgol M. , Jasińska B. , Kamińska D. , Kapłon Ł. , Korcyl G. , Kowalski P. , Kozik T. , Krzemień W. , Kubicz E. , Niedźwiecki S. , Pałka M. , Raczyński L. , Rudy Z. , Rundel O. , Słomski A. , Strzelecki A. , Wieczorek A. , Wiślicki W. , Zieliński M. , Zgardzińska B. , Moskal P.

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tom Vol. 60, No. 4, part 1

765--769

EN

The J-PET detector being developed at the Jagiellonian University is a positron emission tomograph composed of the long strips of polymer scintillators. At the same time, it is a detector system that will be used for studies of the decays of positronium atoms. The shape of photomultiplier signals depends on the hit time and hit position of the gamma quantum. In order to take advantage of this fact, a dedicated sampling front-end electronics that enables to sample signals in voltage domain with the time precision of about 20 ps and novel reconstruction method based on the comparison of examined signal with the model signals stored in the library has been developed. As a measure of the similarity, we use the Mahalanobis distance. The achievable position and time resolution depend on the number and values of the threshold levels at which the signal is sampled. A reconstruction method as well as preliminary results are presented and discussed.

17

Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector

31%

Kamińska D. , Gajos A. , Czerwiński E. , Bednarski T. , Białas P. , Gorgol M. , Jasińska B. , Kapłon Ł. , Korcyl G. , Kowalski P. , Kozik T. , Krzemień W. , Kubicz E. , Niedźwiecki S. , Pałka M. , Raczyński L. , Rudy Z. , Rundel O. , Sharma N. G. , Silarski M. , Słomski A. , Strzelecki A. , Wieczorek A. , Wiślicki W. , Zieliński M. , Zgardzińska B. , Moskal P.

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tom Vol. 60, No. 4, part 1

729--732

EN

In this paper, we present prospects for using the Jagiellonian positron emission tomograph (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 the unique time and angular resolution combined with a high geometrical acceptance. Achieving the aforementioned is possible because of the application of polymer scintillators instead of crystals as detectors of annihilation quanta.

18

Processing optimization with parallel computing for the J-PET scanner

26%

Krzemień W. , Bała M. , Bednarski T. , Białas P. , Czerwiński E. , Gajos A. , Gorgol M. , Jasińska B. , Kamińska D. , Kapłon Ł. , Korcyl G. , Kowalski P. , Kozik T. , Kubicz E. , Niedźwiecki S. , Pałka M. , Raczyński L. , Rudy Z. , Rundel O. , Sharma N. G. , Silarski M. , Słomski A. , Stola K. , Strzelecki A. , Trybek D. , Wieczorek A. , Wiślicki W. , Zieliński M. , Zgardzińska B. , Moskal P.

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tom Vol. 60, No. 4, part 1

745--748

EN

The Jagiellonian Positron Emission Tomograph (J-PET) collaboration is developing a prototype time of flight (TOF)-positron emission tomograph (PET) detector based on long polymer scintillators. This novel approach exploits the excellent time properties of the plastic scintillators, which permit very precise time measurements. The very fast fi eld programmable gate array (FPGA)-based front-end electronics and the data acquisition system, as well as low- and high-level reconstruction algorithms were specially developed to be used with the J-PET scanner. The TOF-PET data processing and reconstruction are time and resource demanding operations, especially in the case of a large acceptance detector that works in triggerless data acquisition mode. In this article, we discuss the parallel computing methods applied to optimize the data processing for the J-PET detector. We begin with general concepts of parallel computing and then we discuss several applications of those techniques in the J-PET data processing.

19

List-mode reconstruction in 2D strip PET

26%

Białas P. , Kowal J. , Strzelecki A. , Bednarski T. , Czerwiński E. , Giergiel K. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowalski P. , Kozik T. , Krzemień W. , Molenda M. , Moskal I. , Moskal P. , Niedźwiecki S. , Pałka M. , Pawlik M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Silarski M. , Słomski A. , Smyrski J. , Szymański K. , Wiślicki W. , Witkowski P. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 1

9--12

EN

Using a theory of list-mode maximum likelihood expectation-maximization (MLEM) algorithm, in this contribution, we present a derivation of the system response kernel for a novel positron emission tomography (PET) detector based on plastic scintillators.

20

Simulations of γ quanta scattering in a single module of the J-PET detector

26%

Szymański K. , Moskal P. , Bednarski T. , Białas P. , Czerwiński E. , Giergiel K. , Kapłon Ł. , Kochanowski A. , Korcyl G. , Kowal J. , Kowalski P. , Kozik T. , Krzemień W. , Molenda M. , Moskal I. , Niedźwiecki S. , Pałka M. , Pawlik-Niedźwiecka M. , Raczyński L. , Rudy Z. , Salabura P. , Gupta-Sharma N. , Silarski M. , Słomski A. , Smyrski J. , Strzelecki A. , Witkowski P. , Wiślicki W. , Zieliński M. , Zoń N.

Bio-Algorithms and Med-Systems

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2014

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tom Vol. 10, no. 2

71--77

EN

This article describes the simulations of the scattering of annihilation γ quanta in a strip of a plastic scintillator. Such strips constitute the basic detection modules in a newly proposed positron emission tomography (PET), which utilizes plastic scintillators instead of inorganic crystals. An algorithm simulating the chain of Compton scatterings was elaborated and a series of simulations have been conducted for the scintillator strip with a cross-section of 5×19 mm. The results indicate that secondary interactions occur only in the case of about 8% of the events and only 25% of these events take place in the distance larger than 0.5 cm from the primary interaction. Also, the light signals produced at the primary and secondary interactions overlap with the delay, the distribution of which is characterized by a full width at half-maximum (FWHM) of about 40 ps.