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Tytuł:
Checkerboard-Like Charge Ordering in Underdoped Cuprates
Autorzy:
Wróbel, P.
Powiązania:
https://bibliotekanauki.pl/articles/2046738.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.20.Mn
71.10.Fd
Opis:
Recent scanning tunneling microscopy measurements which indicate the formation of two-dimensional density modulations at some doping levels in cuprates were reviewed. A model of hard-core bosons which represent bound hole pairs in the two-dimensional doped antiferromagnet was discussed in the context of these experimental results. By means of an exact numerical diagonalization it was shown that the Coulomb repulsion between bosons brings about the formation of charge modulations.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 533-539
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In the Search of Electron Correlation Effects in DNA
Autorzy:
Wróbel, A.
Wróbel, P.
Powiązania:
https://bibliotekanauki.pl/articles/1537235.pdf
Data publikacji:
2010-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.14.gk
75.20.-g
71.10.Fd
Opis:
We discuss the energy scale separation induced in DNA by gaps between molecular orbital states of individual bases and by electron correlations. We also demonstrate how this separation gives rise to effective low energy models of electron transport in DNA.
Źródło:
Acta Physica Polonica A; 2010, 118, 2; 409-412
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonfrustrated Antiferromagnet in a Frustrated Lattice Due to Charge Ordering: A Scenario for Pairing in Layered Cobaltates
Autorzy:
Wróbel, P.
Suleja, W.
Powiązania:
https://bibliotekanauki.pl/articles/2047314.pdf
Data publikacji:
2007-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
74.20.Mn
75.50.Ee
Opis:
The mechanism of pairing-symmetry selection in the weakly electron doped t-J model on the honeycomb lattice has been analyzed. The discussion of that problem has been motivated by some recent suggestions that due to charge ordering which may take place in the unconventional superconductor Na$\text{}_{x}$CoO$\text{}_{2}$· yH$\text{}_{2}$O at doping levels near x=1/3 the physics of CoO$\text{}_{2}$ planes may be effectively described in terms of a model for a weakly electron doped antiferromagnet on the honeycomb lattice. In the current publication the main emphasis has been put on reviewing experimental and theoretical work, the results of which support the scenario of charge order. In the calculation, the so-called string picture has been used. It has been demonstrated that spin fluctuations may induce in the honeycomb lattice the formation of an unconventional two-particle bound state. Upon the condensation of bound particles this mechanism may give rise to unconventional pairing. The critical value of the ratio J/t which is sufficient to induce binding has not been evaluated. It has been assumed instead that in the case of cobaltates some additional isotropic attractive interaction, for example phonon mediated, is active. Despite that the exchange of spin fluctuations is not a dominating interaction, it selects the symmetry of the paired state because it is anisotropic. C$\text{}_{3v}$ is the relevant point group for the t-J model on the honeycomb lattice. It has been shown that the bound state of two additional electrons doped to the half-filled antiferromagnetically ordered system has zero total momentum and p-wave symmetry of the irreducible representation E. The expected paired state is a mixture of a singlet and a triplet because the honeycomb lattice does not possess the inversion symmetry.
Źródło:
Acta Physica Polonica A; 2007, 111, 4; 563-572
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymmetric Tunneling Conductance in Doped Antiferromagnets
Autorzy:
Maciąg, A.
Wróbel, P.
Powiązania:
https://bibliotekanauki.pl/articles/2046776.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
74.20.Mn
74.25.Fy
Opis:
We calculate the tunneling conductance in the framework of the spin polaron model, which is an effective model for the t-J model, in the limit where at least short-range antiferromagnetic correlations exist. We show that both in the normal state and in the superconducting state the asymmetry of tunneling conductance is present. This fact is the implication of the particle-hole asymmetry of the spin polaron Hamiltonian in the limit of low density of spin polarons which are quasiparticles emerging in a hole doped antiferromagnet. Experimental evidence of analogous asymmetric tunneling conductance was found in the tunneling spectroscopy measurements of high T$\text{}_{c}$ superconductors.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 607-610
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pairing-Symmetry Selection in a Weakly Doped Canted Antiferromagnet on the Triangular Lattice
Autorzy:
Wróbel, P.
Suleja, W.
Powiązania:
https://bibliotekanauki.pl/articles/1812329.pdf
Data publikacji:
2008-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
74.20.Mn
75.50.Ee
Opis:
The mechanism of superconductivity generation by spin fluctuations in the electron doped canted antiferromagnet on the triangular lattice was analyzed. The underlying assumption is that the formation of the bound state is the prerequisite of pairing. The outcome of this analysis is also valid if an additional isotropic attraction is active but the anisotropic spin-fluctuation mediated force decides on the symmetry of the two-particle bound state. When the canted antiferromagnetic state is generated, the symmetry of the point group $C_{6v}$ for the triangular lattice is lowered to the symmetry of $C_{3v}$. It is demonstrated that spin fluctuations definitely favor the p-wave bound state, which transforms according to the E representation of $C_{3v}$. Since the inversion is not an element of $C_{3v}$, the parity is not a good quantum number and thus the predicted paired state will be a mixture of singlet and triplet. Such a scenario may be relevant to physics of superconducting triangular cobaltates or organics.
Źródło:
Acta Physica Polonica A; 2008, 114, 1; 225-228
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Electronic Structure on the Phase Diagram of Weakly Doped Superconducting Cuprates
Autorzy:
Maciąg, A. M.
Wróbel, P.
Powiązania:
https://bibliotekanauki.pl/articles/2047334.pdf
Data publikacji:
2007-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
74.20.Mn
74.25.Dw
Opis:
Motivated by the difference between the experimental phase diagram of cuprates and expectations of the t-J model, we analyze the influence of the electronic structure on superconducting state generation for small levels of doping. Following some theoretical studies of the Fermi surface for hole doped superconducting cuprates we base our calculations on the t-t'-t''-J model. We construct the spin polaron model, which is an effective model for the t-J model, and we expand it by adding the new terms related to the next neighbor hopping integrals t' and t''. In the framework of this model we study evolutions of superconducting correlation functions with doping. As a result of numerical calculations we find out that superconducting state vanishes for small levels of doping and finite values of t' and t''. This is in qualitative agreement with experimental results.
Źródło:
Acta Physica Polonica A; 2007, 111, 5; 721-725
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crisis Management Model for Large Urban Agglomerations
Model zarządzania kryzysowego dużą aglomeracją miejską
Autorzy:
Szczurek, T.
Bryczek-Wróbel, P.
Powiązania:
https://bibliotekanauki.pl/articles/373504.pdf
Data publikacji:
2018
Wydawca:
Centrum Naukowo-Badawcze Ochrony Przeciwpożarowej im. Józefa Tuliszkowskiego
Tematy:
crisis management
agglomeration
public administration
security
zarządzanie kryzysowe
aglomeracja
administracja publiczna
bezpieczeństwo
Opis:
Purpose: Presentation of a model solution for a crisis management system for large urban agglomerations, assuming that such a model should form part of the current crisis management structure at the national and provincial levels. Introduction: The intensive urbanisation of areas adjacent to large urban centres poses new challenges for the crisis management system. There are two types of agglomerations in Poland, namely monocentric agglomerations consisting of smaller towns concentrated around one large city (e.g., Warsaw agglomeration) and polycentric agglomerations consisting of several or more large cities (e.g., Silesian agglomeration). In each agglomeration – regardless of its type – there is a so-called “leading city”, which is the capital city of the province and at the same time the city with the district rights. An example of such a city is Warsaw, where the crisis management system has been functioning well for several years and it is different than in other agglomerations. Therefore, it seems reasonable to examine whether it would be possible to create a crisis management system model for other Polish agglomerations based on the Warsaw practices. Methodology: A comparative analysis of selected agglomerations and crisis management frameworks across entities forming these agglomerations was used to find the baseline data for the model solution. The evaluation of the existing solutions at the Warsaw agglomeration level was obtained through a diagnostic survey conducted among the employees of local government administration. Conclusions: The results of our diagnostic survey support the crisis management model adopted in Warsaw. The model solution for the crisis management system for large urban agglomerations may be based on solutions adopted and well tried in the Capital City of Warsaw. The model takes into account the creation of the Security and Crisis Management Office for the Agglomeration (BBiZKA) directly subordinate to the Mayor of the provincial city. A strong crisis management centre of the agglomeration would be a permanent element of BBiZKA, the Agglomeration Crisis Management Team would be the advisory element for the Mayor of the city. The Security and Crisis Management Office for the Agglomeration could be established at the expense of the liquidation of dispersed crisis management centres in the cities and municipalities forming the agglomeration. In the national crisis management system, the Crisis Management Centre of the Agglomeration would – as in the case of Warsaw – be subordinated to the Provincial Crisis Management Centre.
Cel: Przedstawienie rozwiązania modelowego dla systemu zarządzania kryzysowego dużą aglomeracją miejską, przy założeniu, że model taki powinien się wpisywać w aktualnie obowiązującą strukturę zarządzania kryzysowego na szczeblu kraju i województwa. Wprowadzenie: Intensywna urbanizacja terenów przyległych do dużych ośrodków miejskich stwarza nowe wyzwania przed systemem zarządzania kryzysowego. W Polsce występują dwa rodzaje aglomeracji. Aglomeracje monocentryczne składające się z mniejszych miejscowości skupionych wokół jednego dużego miasta (np. aglomeracja warszawska) oraz aglomeracje policentryczne składające się z kilku lub kilkunastu dużych miast (np. aglomeracja śląska). W każdej aglomeracji – niezależnie od typu – występuje tzw. „miasto wiodące”, którym jest stolica województwa i jednocześnie miasto na prawach powiatu. Takim miastem jest Warszawa, w której od kilku lat dobrze funkcjonuje – inny niż w pozostałych aglomeracjach – system zarządzania kryzysowego. Wydaje się zatem zasadne zbadanie, czy w oparciu o wzorce warszawskie nie można byłoby stworzyć modelu systemu zarządzania kryzysowego dla innych polskich aglomeracji. Metodologia: W poszukiwaniu danych wyjściowych dla rozwiązania modelowego zastosowano analizę porównawczą wybranych aglomeracji i struktur zarządzania kryzysowego podmiotów tworzących te aglomeracje. Ocenę dotychczasowych rozwiązań na szczeblu aglomeracji warszawskiej uzyskano metodą sondażu diagnostycznego przeprowadzonego wśród pracowników administracji samorządowej. Wnioski: Wyniki sondażu diagnostycznego przemawiają na korzyść przyjętego w Warszawie modelu zarządzania kryzysowego. Modelowe rozwiązanie dla systemu zarządzania kryzysowego dużą aglomeracją miejską może być oparte na rozwiązaniach przyjętych i sprawdzonych w Mieście Stołecznym Warszawie. Model uwzględnia utworzenie Biura Bezpieczeństwa i Zarządzania Kryzysowego Aglomeracji (BBiZKA) podległego bezpośrednio prezydentowi miasta wojewódzkiego. Stałym elementem BBiZKA byłoby silne Centrum Zarządzania Kryzysowego Aglomeracji, a elementem opiniodawczo-doradczym prezydenta miasta byłby Zespół Zarządzania Kryzysowego Aglomeracji. Biuro Bezpieczeństwa i Zarządzania Kryzysowego Aglomeracji mogłoby powstać kosztem likwidacji rozproszonych centrów zarządzania kryzysowego w miastach i gminach tworzących tę aglomerację. W ogólnokrajowym systemie zarządzania kryzysowego, Centrum Zarządzania Kryzysowego Aglomeracji byłoby – podobnie, jak w Warszawie – podporządkowane Wojewódzkiemu Centrum Zarządzania Kryzysowego.
Źródło:
Bezpieczeństwo i Technika Pożarnicza; 2018, 49, 1; 102-110
1895-8443
Pojawia się w:
Bezpieczeństwo i Technika Pożarnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin Polarons in Weakly Doped Antiferromagnets: Experimental Evidence Obtained for Cuprates
Autorzy:
Wróbel, P.
Suleja, W.
Eder, R.
Powiązania:
https://bibliotekanauki.pl/articles/1812270.pdf
Data publikacji:
2008-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.27.+a
71.10.Fd
74.72.-h
Opis:
The mechanism of spin polaron formation in moderately doped cuprates is discussed. These objects represent holes embedded into heavy clouds formed by spin fluctuations. Wave functions of spin polarons are spatially confined due to the increase in the exchange energy which is induced by hole motion giving rise to the creation of spin fluctuations. These wave functions are eigenstates of an "unperturbed" Hamiltonian which is defined by processes responsible for the tendency toward confinement. The eigenstates transform according to different irreducible representations of the point group reflecting the symmetry of the problem. Thus, the spin polarons being local wave functions resemble orbital states. The spectrum of optical conductivity in the mid-infrared range is determined by transitions between s-wave and p-wave spin polarons. The hybridization between different spin polarons which is induced by some high order processes gives rise to the formation of energy bands. The pronounced transfer of the spectral weight between different bands is induced by the coupling between spin fluctuations created by the hopping hole and local quantum fluctuations in the empty antiferromagnetic background from which an electron has been rejected, for example during the photoemission process. The form of the energy dispersion for spin polarons gives rise to the formation of a small Fermi surface at the low hole-doping range. These three above mentioned phenomena were observed in cuprates which seems to confirm the spin polaron scenario. The discussion of related experiments is the additional objective of this paper.
Źródło:
Acta Physica Polonica A; 2008, 114, 1; 51-58
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cooper Pair in Two Nonstandard Situations
Autorzy:
Wróbel, P.
Starypan, Z.
Kaczmarczyk, J.
Spałek, J.
Powiązania:
https://bibliotekanauki.pl/articles/2046740.pdf
Data publikacji:
2006-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.20.-z
74.25.Jb
71.10.-w
Opis:
We summarize briefly our recent work on the bound states of two electrons (Cooper pairs) in two nonstandard situations: when the quasiparticle masses depend on spin and when an electron pair is localized on a two-dimensional quantum dot and placed in an applied magnetic field. In both cases we are dealing with an extension of the original Cooper approach. The applicability of the results is briefly mentioned.
Źródło:
Acta Physica Polonica A; 2006, 109, 4-5; 541-548
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unconventional Superconductivity, Spontaneous Time-Reversal Symmetry Breaking and Lowering of Kinetic Energy in Doped, Short-Range Antiferromagnets
Autorzy:
Wróbel, P.
Maciąg, A.
Eder, R.
Fulde, P.
Micnas, R.
Powiązania:
https://bibliotekanauki.pl/articles/2038385.pdf
Data publikacji:
2004-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.20.Mn
71.10.Fd
Opis:
In this paper we focus on the anomalous temperature dependence of the in-plane conductivity and symmetry mixing of the superconducting order parameter observed in various experiments on cuprates. We show that the one-band Hubbard model is not capable of describing the physics of cuprates because the kinetic energy is lowered in this model in the superconducting state, which contradicts experimental observations. The proper model to investigate doped, short-range antiferromagnets is the t-J model, for which our results agree with experiments. We analyze a spin polaron model, that is an effective model for a doped antiferromagnet. In the framework of this model we also study the superconducting order-parameter symmetry-mixing phenomenon. We show that the expected mixing of d-wave symmetry with p-wave symmetry takes place in the superconducting order-parameter at a finite value of the doping parameter. This symmetry mixing brakes the time-reversal symmetry.
Źródło:
Acta Physica Polonica A; 2004, 106, 5; 575-581
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spin Polaron-Bipolaron Scenario of Three Gap-Like Energy Scales in Superconducting Cuprates
Autorzy:
Wróbel, P.
Maciąg, A.
Suleja, W.
Eder, R.
Micnas, R.
Powiązania:
https://bibliotekanauki.pl/articles/1536806.pdf
Data publikacji:
2010-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.20.Mn
74.72.Kf
Opis:
We argue that three gaps observed in underdoped cuprates can be attributed to the formation of antiferromagnetic spin polarons and bipolarons. Within the spin polaron scenario the antinodal pseudogap at he high energy scale originates from the change of the Fermi surface topology, induced by antiferromagnetic correlations. That change gives rise to the diminishing of the spectral weight at the antinodal region near the Brillouin zone boundary. We demonstrate that effect by analyzing effective models of doped antiferromagnets. The second type of pseudogap appearing at the intermediate energy scale originates from the phenomena which are precursory to superconductivity and predominantly concern the portion of the Fermi surface near the nodal region. In order to analyze the latter phenomenon we use the negative U Hubbard model, in which many details typical to spin polaron physics are neglected, but which contains the essential ingredient of it, that is the strong short range attraction. The lowest energy scale is related to the true superconducting gap which develops with doping, although both types of pseudogap diminish with doping. This behavior can be explained by the fact that the spin polaron band is empty in the undoped system and therefore the formation of the superconducting state in the system is forbidden. Due to a pedagogical character of this report, we present in the introduction a short overview of mostly recent experimental results which are related to the gap-pseudogap physics.
Źródło:
Acta Physica Polonica A; 2010, 118, 2; 292-298
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigating the content of microplastics and other extraneous particles in Polish bottled water
Autorzy:
Aleksander-Kwaterczak, Urszula
Gaj, Dominika
Stelmach, Alex
Wróbel, Tomasz P.
Powiązania:
https://bibliotekanauki.pl/articles/27310134.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
plastic bottles
drinking water
solid particles
polymers
microplastics
FT-IR spectroscopy
Opis:
Bottled water has enjoyed a global increase in popularity since it is generally perceived to be superior in quality to tap water and necessary when tap water is non-potable. As a result, ensuring that it meets the requisite quality standards is of vital importance. This work aims to examine the content of solid particles, including microplastics, in bottled water available in Polish stores. The second aspect is the preliminary determination of the influence of the water gassing process, together with thermal and light factors, on the content of particles in the water. The number of particles was counted by colour and shape, with the number ranging from 87 to 188 per litre of water; on average, there were 136 ±32 particles per litre of water, demonstrating that water from disposable plastic bottles is contaminated with various substances. The difference in the number of particles may be due to the origin of the waters, the processes they were subjected to prior to bottling, the properties of the bottles as packaging, and the conditions and length of storage and transport. Additional Fourier-transform infrared spectroscopy (FT-IR) analysis confirmed that about 75% of the particles were polymers, and 50% of them were plastics. Particularly alarming is the fact that the bottled waters mostly contained microplastic particles (MP) of smaller sizes, the kind which is recognized as being the most dangerous to human health. In the study, most particles were in the form of irregular shapes, which may indicate that they come from the destruction of waste or plastic products. This is also indicated by the domination of colourless particles. More particles were found in waters exposed to high and low temperatures than in waters stored at room temperature, potentially indicating that storage conditions for drinking water are important. Taking into account the results obtained, increasing attention should be paid to the health risks posed by such microplastics and there is a clear need to introduce legal regulations on the matter. The lack of any legal guidelines or unified standards in the field of MP research means that the results are not always representative, and it also makes it difficult to compare the results from different studies.
Źródło:
Geology, Geophysics and Environment; 2023, 49, 4; 335--353
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Burial and thermal history and hydrocarbon generation modelling of the Lower Palaeozoic source rocks in the Kraków–Rzeszów area (SE Poland)
Autorzy:
Kosakowski, P.
Wróbel, M.
Powiązania:
https://bibliotekanauki.pl/articles/191542.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
source rocks
1-D modelling
generation
expulsion
Lower Palaeozoic
south-eastern Poland
Opis:
Burial history, thermal maturity and timing of hydrocarbon generation were modelled for the Ordovician and Silurian source rocks in the basement of the Carpathian Foredeep. 1-D modelling was carried out for wells located in the area between Kraków and Rzeszów cities (SE Poland). The following wells were modelled: Będzienica 2, Hermanowa 1, Nawsie 1, Nosówka 2 and 12, Pilzno 40, and Zawada 8K. The Ordovician and Silurian source rocks, containing oil-prone Type-II kerogen, are generally immature showing less than 0.5% reflectance of vitrinite-like macerals (Ro), in most of the Kraków–Rzeszów area and only in the eastern part the organic matter is early mature, reaching 0.7% equivalent Ro. The highest thermal maturity is found in the eastern part of the study area, near Rzeszów city, where the Lower Palaeozoic strata are buried to the greatest depth. Maturity modelling shows that the source rocks reached the initial phase of the “oil window” only in the eastern part of the area, whereas they are immature in the larger, western portion of the area. In addition, modelling indicates that the onset of petroleum generation started in the late Miocene, after the Outer Carpathian overthrust phase. The generation processes in the eastern part of the analysed area reached the main and late generation phase. The generated hydrocarbons were mostly expelled from the source rocks. In the western part of the study area the generation process has not been initialized.
Źródło:
Annales Societatis Geologorum Poloniae; 2011, 81, No 3; 459-471
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Signature pre - procesing based on walsh coefficients
Autorzy:
Porwik, P.
Wróbel, K.
Powiązania:
https://bibliotekanauki.pl/articles/332876.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
analiza graficzna
rozpoznawanie podpisu
transformacja Walsha
współczynniki Walsha
maszyna wektorów podpierających
signature analysis and recognition
Walsh transform
Walsh coefficients
support vector machine (SVM)
Opis:
Recognition and verification of persons are difficult and important tasks today. In many fields of human activities (driver's licenses, passports, electronic cards, etc.), signature recognition of person is needed. Hence, it inspires the development of a wide range of automatic identification systems. Signatures have been used for many centuries as a method of people's identification. Signatures recognition was performed manually by experts in the past. Nowadays, these procedures are very often automatically applied. In this paper the system that automatically authenticates documents based on the owner's handwritten signature is presented.
Źródło:
Journal of Medical Informatics & Technologies; 2008, 12; 57-61
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrocarbon generation/expulsion modelling of the lower Paleozoic potential source rocks in the Gryfice and Kolobrzeg blocks (NW Poland)
Autorzy:
Wróbel, M.
Kosakowski, P.
Poprawa, P.
Powiązania:
https://bibliotekanauki.pl/articles/2059060.pdf
Data publikacji:
2010
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Gryfice and Kolobrzeg blocks
Lower Paleozoic
source rock
burial history
thermal evolution
petroleum processes
Opis:
The lower Paleozoic source rocks in the offshore part of the Gryfice and Kolobrzeg blocks (NW Poland) were studied through geochemical data and numerical modelling. The geochemical study revealed a presence of effective source rocks in Caradocian strata, but with low hydrocarbon potential. The remaining lower Paleozoic source rock horizons were not documented by core samples. The timing of hydrocarbon generation and expulsion was modelled for the K1-1/86 and L2-1/87 boreholes located in the Gryfice and Kolobrzeg blocks, respectively. 1-D and 2-D modelling indicated that in the Kolobrzeg Block the onset of petroleum generation occurred at the end of the Silurian and the beginning of the Devonian. Source rocks in the Gryfice Block reached the early stage of oil generation at the beginning of the Permian and generation processes were completed by the end of the Triassic. Migration of hydrocarbons from source rocks began in the Carboniferous in both the Gryfice and Kolobrzeg blocks and lasted to the end of the Mesozoic. During hydrocarbon migration, an intensive dispersion process was observed, caused by leaking along the fault planes. The modelling revealed that hydrocarbons may have accumulated in Devonian reservoirs. The lack of any discovered accumulations could be the result of hydrocarbon dispersion caused by tectonic deformation and intense vertical fault block movements.
Źródło:
Geological Quarterly; 2010, 54, 2; 183-196
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 85

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