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Tytuł:
Variance-Based Spillover Analysis between Stock Markets: A Time Varying Parameter Approach
Autorzy:
Özün, A.
Ertuğrul, H.
Powiązania:
https://bibliotekanauki.pl/articles/1195957.pdf
Data publikacji:
2014-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
89.65.Gh
05.10.-a
Opis:
This paper proposes a variance-based spillover impact analysis embedded with a dynamic Kalman filtering in order to detect a causality relationship from the US stock markets into the European and emerging stock markets during the financial crisis. It has mainly two new contributions to the literature. Firstly, it uses variance rather than returns to analyze the spillover impact between the markets. Secondly, and more importantly, it is an econophysics research as it examines causality relationship with the Kalman filtering in physics. We calculate time-dependent conditional stock market variances for Dow Jones, DAX, FTSE, RTS (Russia), and BIST (Turkey) by employing SWARCH model. The empirical analysis examines the causal relationship between Dow Jones into the other stock markets employing Granger causality tests in order to detect the direction of volatility spillover relationship. As an embedded analysis, we follow a dynamic approach by using the Kalman filtering as a time varying parameter model to depict the time varying interaction between stock markets volatilities. The empirical results point out unidirectional Granger causality from Dow Jones to the other markets indicating the spillover impact of the volatility starting from the US markets and expanded into the world in the latest global crisis.
Źródło:
Acta Physica Polonica A; 2014, 125, 1; 155-157
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamics of the Belief Propagation for the Ising Model
Autorzy:
Siudem, G.
Świątek, G.
Powiązania:
https://bibliotekanauki.pl/articles/1388282.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.10.-a
05.45.-a
89.65.-s
Opis:
The Belief Propagation algorithm is a popular technique of solving inference problems for different graph-like structures. We present a discussion of the dynamics of that algorithm for the Ising model on the square lattice. Our main goal was to describe limit fixed points for that algorithm, which are strictly connected with the marginal probabilities and stationary points of the Bethe Free Energy. Analytical considerations provide an exact analysis of a class of symmetrical points while numerical simulations confirm that for small lattices there are no non-symmetrical points. Notwithstanding the prevalent use of the Belief Propagation as an inference tool we present a sociophysical interpretation of its dynamics. In that case our considerations may be viewed as an investigation of the possible fixed points of the social dynamics.
Źródło:
Acta Physica Polonica A; 2015, 127, 3A; A-145-A-149
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of Potential Energy Shape on the Total Electrical Efficiency of the Energy Harvester
Autorzy:
Kucab, K.
Górski, G.
Powiązania:
https://bibliotekanauki.pl/articles/1032464.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.10.-a
88.05.-b
41.20.Gz
Opis:
In this theoretical work we analyze the total effective electric power versus base acceleration amplitude generated by the energy harvesting system with an electromagnetic transducer. We compare the results for both linear and nonlinear case. The transition from linear to nonlinear behavior of the system can be achieved by the change of device geometry. To improve the power efficiency of our device we also examine the dependence of crossover point of acceleration amplitudes where generated power in the nonlinear system starts to exceed the generated power in the linear regime. We have found that the crossover point can be moved towards relatively small base acceleration values by appropriate selection of system nonlinearity "strength".
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 118-120
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Heuristic for Approximating Extreme Negative Price Returns in Financial Markets
Autorzy:
Manhire, J.
Powiązania:
https://bibliotekanauki.pl/articles/1029529.pdf
Data publikacji:
2018-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.70.-c
05.10.-a
89.65.Gh
Opis:
The paper describes the behavior of financial markets as functions of the variables ``price return'' and ``time'' based on the net difference between ask and bid volumes over a unit period, thereby suggesting that at least a negative non-trivial price return extreme exists for a unit period. This admittedly heuristic approach also offers a method for approximating these negative price return extremes for a specific unit period. Limitations and applications are discussed.
Źródło:
Acta Physica Polonica A; 2018, 133, 6; 1408-1413
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mutual Information-Based Hierarchies on Warsaw Stock Exchange
Autorzy:
Fiedor, P.
Powiązania:
https://bibliotekanauki.pl/articles/1388360.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.10.-a
64.60.aq
89.65.-s
89.70.-a
Opis:
A popular method for network analysis of financial markets is a notable part of econophysics research. The networks created in such efforts are focused exclusively on linear correlations between stocks. While Pearson's correlation is the obvious starting point, it would be useful to look at its alternatives as to whether they provide improvements to this methodology, particularly given Pearson's correlation coefficient considers only a limited class of association patterns. We propose to use mutual information-based hierarchical networks, as mutual information is a natural generalisation of Pearson's correlation. We estimate mutual information using naive plug-in estimator as consistent bias is not harmful to this application, however other methods may also be used. We then transform the mutual information into an Euclidean metric and create minimal spanning trees and maximally filtered planar graphs. We apply this methodology to Warsaw Stock Exchange for years between 2000 and 2013, and comment on the differences with the standard methodology, as well as the structural changes on Warsaw Stock Exchange which the study reveals.
Źródło:
Acta Physica Polonica A; 2015, 127, 3A; A-33-A-37
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Transformations in Pyrochlores Irradiated with Swift Heavy Ions: Influence of Composition and Chemical Bonding
Autorzy:
Sattonnay, G.
Thomé, L.
Sellami, N.
Monnet, I.
Grygiel, C.
Legros, C.
Tetot, R.
Powiązania:
https://bibliotekanauki.pl/articles/1400452.pdf
Data publikacji:
2013-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.80.-x
61.82.Ms
61.05.cp
05.10.-a
Opis:
$Gd_2Ti_2O_7$ and $Gd_2Zr_2O_7$ pyrochlores were irradiated with swift heavy ions in order to investigate the effects of the chemical composition on the structural changes induced by high electronic excitation. The XRD results show that the structural modifications induced by irradiation with 93 MeV Xe ions are strongly dependent on the sample composition: $Gd_2Ti_2O_7$ is readily amorphized, whereas $Gd_2Zr_2O_7$ is transformed into a radiation-resistant anion-deficient fluorite structure. Atomistic simulations with the second-moment tight-binding QEq model allow us to calculate the lattice properties of both $Gd_2Ti_2O_7$ and $Gd_2Zr_2O_7$, and also to quantify the degree of covalency and ionicity in these compounds. These calculations clearly show that $Gd_2Ti_2O_7$ is more covalent than $Gd_2Zr_2O_7$, thus confirming that the amorphization resistance can be related to the covalent character of insulators.
Źródło:
Acta Physica Polonica A; 2013, 123, 5; 862-866
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibration Noise Harshness of a Light Truck Driveshaft, Analysis and Improvement with Six Sigma Approach
Autorzy:
Ertürk, A.
Karabay, S.
Baynal, K.
Korkut, T.
Powiązania:
https://bibliotekanauki.pl/articles/1033531.pdf
Data publikacji:
2017-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
06.30.Gv
34.50.Ez
43.58.+z
46.40.-f
05.10.-a
Opis:
This paper deals with the application of six sigma methodology for optimization of a cardan shaft. The aim of this optimization is to reduce vibration of the drive shaft and consequently improve vibration noise harshness of the vehicle. The six sigma methodology has been applied to a light truck, which has received excessive vibration and noise complaints. The define-measure-analyze-improve-control approach has been followed to enhance the vibration noise harshness statistics. The result shows that all expected vibration noise harshness performance targets have been dramatically improved when compared to the initial values. As a conclusion, the case study on a light truck is a useful reference to improve vehicle performance for vibration noise harshness.
Źródło:
Acta Physica Polonica A; 2017, 131, 3; 477-480
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza możliwości wykorzystania odpadu energetycznego z mokrego odsiarczania spalin (10 01 05) w mieszaninach zestalających w kopalniach węgla kamiennego
Analysis of possibilities for utilizing power generation waste from a wet flue gas desulphurization method (code 10 01 05) as a component of solidifying mixtures being applied in hard coal underground mines
Autorzy:
Plewa, F.
Popczyk, M.
Zając, A.
Pierzyna, P.
Powiązania:
https://bibliotekanauki.pl/articles/282482.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
górnictwo
doszczelnianie
odpady energetyczne
reagips
mining
grouting
power generation waste
REA-gypsum
Opis:
Od kilkunastu lat energetyka zawodowa coraz częściej wykorzystuje do odsiarczania spalin metody mokre, charakteryzujące się bardzo wysoką sprawnością, kształtującą się na poziomie oko?o 90-95%. Produktem ubocznym powstaj?cym podczas pracy instalacji jest tzw. reagips. Produkt ten w Polsce masowo wykorzystywany jest do produkcji różnych elementów gipsowych, z których najpopularniejszym są płyty gipsowo-kartonowe. Potencjalnym obszarem wykorzystania reagipsów może być także górnictwo podziemne, które masowo zagospodarowuje różne odpady drobnofrakcyjne pochodzące z energetyki zawodowej w technologii doszczelniania zrobów zawałowych. Jednakże z uwagi na brak właściwości wiążących reagipsu oraz wymagania dotyczące materiałów do technologii doszczelniania zawarte w normie PN-G 11011:1998, należy reagips wprowadzić do mieszaniny popiołowo--wodnej sporządzonej na bazie popiołu o właściwościach wiążących. W artykule przedstawiono wyniki badać właściwości fizykomechanicznych oraz wymywalności substancji chemicznych hydromieszanin popio?u o kodzie 100102 z dodatkiem reagipsu w zakresie 0-20% zarobionych wod? kopalnian?. Badane hydromieszaniny miały rozlewność 180, 220 i 260 mm (tab. 1). Na podstawie przedstawionych bada? podstawowych w?asno?ci fizykomechanicznych należ y stwierdzić, że : gęstość zmieniała się od 1362 do 1515 g/dm3 (rys. 1); wskaźnik wodno-popiołowy wynosił od 0,40 do 0,64 (rys. 2); ilość wody nadosadowej przyjmowała wartości od 0,3 do 9,8% (rys. 3); wytrzymałość na ściskanie po 28 dniach wynosiła od 0,12 do 0,43 MPa(rys. 4); rozmakalność zmieniała się od 2 do 48% (rys. 5). Badania wymywalności siarczanów i chlorków na zgodność z wymaganiami normowymi wykonane w akredytowanych laboratoriach wykaza?y nieznaczne przekroczenie chlorków w jednej mieszaninie o rozlewności 180 mm i udziale 20% reagipsu. W przypadku siarczanów przekroczeń wartości normowych nie zanotowano (tab. 2). Jak wynika z analizy wyników wyżej wymienionych bada? w?a?ciwo?ci fizykomechanicznych oraz wymywalności substancji chemicznych hydromieszanin stwierdza się, że wymagania normowe dla technologii doszczelniania zrobów spe?niaj? nast?puj?ce mieszaniny wykonane na bazie popio?u 10 01 02 i wody kopalnianej: przy rozlewności 180 mm z udzia?em reagipsu do 15%, przy rozlewności 220 mm z udzia?em reagipsu do 20%, przy rozlewności 260 mm z udzia?em reagipsu do 20%
For several years, professional power generation more and more often applies wet methods for the desulphurization of flue gases which are characterized by very high efficiency, reaching a level of about 90–95%. A byproduct generated during the operation of such a plant is REA- -gypsum. This product sees broad usage in Poland for the production of different gypsum-based materials of which the most popular are gypsum-cardboards. A potential area where REA-gypsum could be applied is also underground mining which utilizes in bulk different, finely-grained waste, originating from professional power generation mainly in the technology for the grouting of cavings.
Źródło:
Polityka Energetyczna; 2012, 15, 3; 147-157
1429-6675
Pojawia się w:
Polityka Energetyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of the Molecular Shape on Its Thermodynamic Functions
Autorzy:
Lewandowska, A.
Konarski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1813167.pdf
Data publikacji:
2008-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.20.-y
05.70.-a
33.10.Cs
Opis:
Free energy and entropy were calculated for molecules of different shapes in gas phase and under small pressure. The values of the thermodynamic functions were found strongly dependent on the molecular shape. The results obtained were applied to predict the route of internal energy deactivation as well as the preferred form of the molecules examined.
Źródło:
Acta Physica Polonica A; 2008, 113, 4; 1111-1115
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of Particle Transport with External Driving Force and Entropy Barrier
Autorzy:
Li, S.
Zhang, Z.
Chen, D.
Powiązania:
https://bibliotekanauki.pl/articles/1398914.pdf
Data publikacji:
2016-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.40.Jc
05.40.-a
05.10.Gg
05.60.Cd
Opis:
Transport of Brownian particle moving along a three-dimensional throat-like channel is investigated in the presence of an external constant force. The solution of the Fick-Jacobs equation in the situation is solved, and the probability current density and particle current describing the motion of particle are obtained. It is found that entropy barrier and external force can reverse the direction of particle current. The motion of Brownian particle can be tuned by the entropy barrier and the external force.
Źródło:
Acta Physica Polonica A; 2016, 129, 6; 1105-1108
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of a Mixed Hadronic-QGP System with Massive Particles
Autorzy:
Ghenam, L.
El Djoudi, A.
Powiązania:
https://bibliotekanauki.pl/articles/1402384.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
12.38.Mh
12.39.Ba
05.70.-a
05.70.Ce
05.70.Fh
64.10.+h
Opis:
We consider a mixed system of hadronic and quark-gluon plasma (QGP) phases in a finite volume, and use a phenomenological approach with two phases matter equations of state to study the occurring deconfinement phase transition with varying temperature and/or chemical potential. We take into account massive particles in both phases, and calculate several physical quantities describing well the system at the phase transition. We probe the behaviour of these quantities, by examining their variations with temperature and volume at fixed chemical potential, as well as with chemical potential and volume at fixed temperature, in three dimensional plots, and obtain the finite size effects on the deconfinement phase transition.
Źródło:
Acta Physica Polonica A; 2015, 128, 2B; B-341-B-343
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymmetry Coefficients as Indicators of Chaos
Autorzy:
Wąż, P.
Bielińska-Wąż, D.
Powiązania:
https://bibliotekanauki.pl/articles/1584980.pdf
Data publikacji:
2009-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.70.Rr
95.10.Fh
05.45.-a
05.45.Gg
05.45.Tp
Opis:
The aim of this paper is to present a new simple indicator of chaos derived from the dynamics of the motion. For this purpose statistical methods are used. A function describing the motion of the analyzed system (in the example under consideration, the time dependence of the angle of a damped driven pendulum, ω(t)) is recorded in time intervals t∊〈 $T_{s}$, $T_{f_{k}}$〉, k = 1, 2,...K, with $T_{f_{k}}$ > $T_{f_{k-1}}$. Each of the recorded functions is considered as a statistical distribution. The asymmetry coefficients of the set of distributions form a series and their behavior in periodic and chaotic regions is compared. It is shown that the behavior of this series in the chaotic and in the periodic regimes is entirely different. The changes of the asymmetry coefficients for the periodic cases are very regular and for the chaotic ones - random. In periodic cases, the coefficients converge to zero when the length of the distribution increases.
Źródło:
Acta Physica Polonica A; 2009, 116, 6; 987-991
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Irreversible Processes across Narrow Junctions
Autorzy:
Honig, J.
Hoehn, R.
Powiązania:
https://bibliotekanauki.pl/articles/1505330.pdf
Data publikacji:
2011-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.-a
05.70.Ln
44.10.+i
Opis:
The rectification of the second law of thermodynamics is used to directly relate irreversible heat and work transfers to reversible processes. This permits the construction of thermodynamic functions of state that include entropy contributions due to irreversible processes. A general expression is set up to determine the entropy changes in terms of experimentally accessible parameters when a system is interacting with its surroundings via quasistatic irreversible operations. The procedure is used to determine the entropy changes across a narrow junction in terms of pressure and temperature differences between the system and its surroundings, including cyclic processes.
Źródło:
Acta Physica Polonica A; 2011, 119, 3; 323-327
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interplay between endogenous and exogenous fluctuations in financial markets
Autorzy:
Gontis, V.
Powiązania:
https://bibliotekanauki.pl/articles/1075435.pdf
Data publikacji:
2016-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
89.65.Gh
89.75.Da
05.10.Gg
05.40.-a
05.45.Tp
Opis:
We address microscopic, agent based, and macroscopic, stochastic, modeling of the financial markets combining it with the exogenous noise. The interplay between the endogenous dynamics of agents and the exogenous noise is the primary mechanism responsible for the observed long-range dependence and statistical properties of high volatility return intervals. By exogenous noise we mean information flow or/and order flow fluctuations. Numerical results based on the proposed model reveal that the exogenous fluctuations have to be considered as indispensable part of comprehensive modeling of the financial markets.
Źródło:
Acta Physica Polonica A; 2016, 129, 5; 1023-1031
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Order in Quantum Compass and Orbital e_{g} Models
Autorzy:
Czarnik, P.
Dziarmaga, J.
Oleś, A.
Powiązania:
https://bibliotekanauki.pl/articles/1029762.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
05.10.Cc
05.70.Fh
75.25.Dk
Opis:
We investigate thermodynamic phase transitions in the compass model and in e_{g} orbital model on an infinite square lattice by variational tensor network renormalization (VTNR) in imaginary time. The onset of nematic order in the quantum compass model is estimated at _{c}/J=0.0606(4). For the e_{g} orbital model one finds: (i) a very accurate estimate of _{c}/J=0.3566± 0.0001 and (ii) the critical exponents in the Ising universality class. Remarkably large difference in frustration results in so distinct values of _{c}, while entanglement influences the quality of _{c} estimation.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 359-361
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Diagrams of the Spin-1/2 Ising-Heisenberg Model on a Triangle-Hexagon Lattice
Autorzy:
Kiššová, J.
Strečka, J.
Powiązania:
https://bibliotekanauki.pl/articles/1506906.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.30.Rt
05.50.+q
05.70.Jk
75.10.Kt
75.10.Jm
75.30.Kz
Opis:
Ground-state and finite-temperature phase diagrams of a geometrically frustrated spin-1/2 Ising-Heisenberg model on a triangle-hexagon lattice are investigated within the generalized star-triangle mapping transformation. It is shown that the ground state is constituted by two different spontaneously long-range ordered phases and one disordered spin-liquid phase.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 730-731
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fatigue Test with Stochastic Differential Equation Modeling
Autorzy:
Eroglu, E.
Guney, I.
Gunes, I.
Powiązania:
https://bibliotekanauki.pl/articles/1490739.pdf
Data publikacji:
2012-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.10.Gg
81.40.Np
05.45.-a
Opis:
In this study, a mathematically polymeric insulator material is modeled which is used as a solid insulator in the industry. ASTM D 2303 in inclined plane test method is utilized in order to observe mechanical effect of vibration. The materials have different deformation times before they are fatigued or not fatigued. Our goal is the mathematical model which has materials at progressive times.
Źródło:
Acta Physica Polonica A; 2012, 121, 1; 36-38
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymmetry Coefficients as Indicators of Chaos: Hyperchaotic Qi System
Autorzy:
Wąż, P.
Bielińska-Wąż, D.
Powiązania:
https://bibliotekanauki.pl/articles/1400122.pdf
Data publikacji:
2013-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.70.Rr
95.10.Fh
05.45.-a
05.45.Gg
05.45.Tp
Opis:
Statistical properties of the hyperchaotic Qi system are studied. The theory, recently formulated and applied for the damped driven pendulum, is used in this investigation. Asymmetry coefficients, related to the statistical moments of distributions composed from the time-series, are shown to behave in a different way for periodic, chaotic and hyperchaotic solutions and are proposed as indicators of chaos and hyperchaos.
Źródło:
Acta Physica Polonica A; 2013, 123, 4; 647-650
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic analysis of a cascade refrigeration system
Autorzy:
Karaali, R.
Powiązania:
https://bibliotekanauki.pl/articles/1065661.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
88.05.Sv
88.10.cn
Opis:
There is a need for cooling by using the waste heat energy in food industry. Absorption cycles can be driven by waste thermal, geothermal, solar or industrial processes energies. In this study, cascade refrigeration system is thermodynamically modeled, and analyzed by using first law of thermodynamics, and exergy method. Thermodynamic properties such as pressure, temperature, entropy, enthalpy, exergy, mass flow rate in each stream are calculated for 50, 75, 100°C and for 0.8, 1.0, and 1.5 MPa pump pressure. A computer program is used that was prepared in FORTRAN by the author for the analyses. It is found that the compression-absorption cascade cooling cycle is appropriate for most of the kind of waste heat applications. Increase of the generator inlet heat temperature increases the generator inlet heat, the absorber outlet heat and the condenser 2 outlet heat energies and decreases the coefficient of performance of the absorption and the overall cycles. The generator heat decreases with increase of the pump pressure. Also increase of the pump pressure decreases the coefficient of performance of the absorption and the overall cycles. Increase of the pump pressure and the generator temperature decreases the exergetic coefficient of performance. Increase of the generator temperature and pump pressure increases the generator inlet exergy. It is concluded that increase of the generator temperature and the pump pressure increases the total destructed exergy of the cycle.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 101-106
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Stochastic Dynamics on the Nuclear Magnetic Resonance in a Field Gradient
Autorzy:
Tóthová, J.
Lisý, V.
Powiązania:
https://bibliotekanauki.pl/articles/1032635.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.60.-k
76.60.Lz
05.40.-a
05.10.Gg
Opis:
In the present contribution, the attenuation function S(t) for an ensemble of spins in a magnetic-field gradient is calculated through an accumulation of the phase shifts in the rotating frame resulting from the changes of the particle displacements. The found S(t) is applicable for any kind of the stochastic motion of spins, including their non-Markovian dynamics with memory. Depending on the considered system, both the classical expressions valid for normal diffusion at long times and new formulae for the short-time Brownian motion can be obtained. Our method is also applicable to the NMR pulse sequences based on the refocusing principle. This is demonstrated by describing the spin echo experiment developed by Hahn.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 1111-1113
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Scattering from a Ring Graph - A~Simple Model for the Study of Resonances
Autorzy:
Waltner, D.
Smilansky, U.
Powiązania:
https://bibliotekanauki.pl/articles/1399052.pdf
Data publikacji:
2013-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.40.Ca
05.45.Mt
03.65.Sq
02.10.Ox
Opis:
Scattering from the very simple ring graph is shown to display several basic features which underlie the complex (chaotic) phenomena observed in scattering from more complex graphs. In particular we demonstrate the appearance of arbitrarily narrow resonances - the "topological resonances" which are directly linked to the existence of cycles. We use the ring graph to study the response of such resonances to perturbations induced by a time-dependent random noise.
Źródło:
Acta Physica Polonica A; 2013, 124, 6; 1087-1090
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A New Microscopic Calculation for the Uniform Electron Fluid
Autorzy:
Bouchebak, A.
Al-Sugheir, M.
Ghassib, H.
Powiązania:
https://bibliotekanauki.pl/articles/1505328.pdf
Data publikacji:
2011-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.30.Fk
71.10.Ay
71.10.Ca
Opis:
The static fluctuation approximation is applied for the first time to an electronic system. A simple model (a uniform electron fluid) is chosen to explore the applicability of static fluctuation approximation to electrons in metals. The thermodynamic properties - the internal energy per particle, the pressure, the entropy per unit volume, the heat capacity per unit volume, and the chemical potential - are calculated over a wide range of densities within the metallic-density region. Finally, the pair-correlation function for the electron fluid is evaluated. Values of this function are then tabulated for zero-interparticle separation at several densities of interest. The results of this work are found to be in good agreement with several other many-body calculations.
Źródło:
Acta Physica Polonica A; 2011, 119, 3; 312-322
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical Study of the Frustrated Ising Antiferromagnet on the Honeycomb Lattice
Autorzy:
Bobák, A.
Lučivjanský, T.
Žukovič, M.
Borovský, M.
Balcerzak, T.
Powiązania:
https://bibliotekanauki.pl/articles/1032632.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
05.70.-a
75.10.Hk
Opis:
We study effects of the next-next-nearest-neighbour antiferromagnetic (J₃ < 0) interaction on critical properties (or phase diagram) of the frustrated spin-½ J₁-J₂-J₃ Ising antiferromagnet on the honeycomb lattice by using the effective-field theory with correlations. Beside the ground-state energy, we find that there is a region of J₃ < 0 in which the frustrated honeycomb lattice antiferromagnet exhibits a tricritical point, at which the phase transition changes from the second order to the first one on the line between Néel antiferromagnetic and paramagnetic phases.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 636-638
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Random Unitary Matrices Associated to a Graph
Autorzy:
Kondratiuk, P.
Życzkowski, K.
Powiązania:
https://bibliotekanauki.pl/articles/1399055.pdf
Data publikacji:
2013-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.10.Yn
03.65.Aa
03.67.Mn
05.45.Mt
05.45.Pq
Opis:
We analyze composed quantum systems consisting of k subsystems, each described by states in the n-}dimensional Hilbert space. Interaction between subsystems can be represented by a graph, with vertices corresponding to individual subsystems and edges denoting a generic interaction, modeled by random unitary matrices of order $n^2$. The global evolution operator is represented by a unitary matrix of size N = n^{k}. We investigate statistical properties of such matrices and show that they display spectral properties characteristic to the Haar random unitary matrices provided the corresponding graph is connected. Thus basing on random unitary matrices of a small size n^2 one can construct a fair approximation of large random unitary matrices of size $n^{k}$. Graph-structured random unitary matrices investigated here allow one to define the corresponding structured ensembles of random pure states.
Źródło:
Acta Physica Polonica A; 2013, 124, 6; 1098-1105
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Regular and Chaotic Behaviour of a Kicked Damped Spin
Autorzy:
Hołyst, J.
Sukiennicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/1920483.pdf
Data publikacji:
1992-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.+b
75.10.Hk
Opis:
The dynamics of a kicked, anisotropic, damped spin is reduced to a two-dimensional map. This map exhibits such features as bifurcation diagrams, regular or chaotic attractors/repellors and intermittent-like transitions between two strange attractors. With increase of damping a transition from chaos to the fixed point attractor occurs. On the contrary to the Hamiltonian case the type of magnetic anisotropy plays a crucial role for damped models.
Źródło:
Acta Physica Polonica A; 1992, 81, 3; 353-360
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Majority-Vote Model on Scale-Free Hypergraphs
Autorzy:
Gradowski, T.
Krawiecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/1388421.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
89.75.Hc
64.60.Cn
05.10.Ln
05.50.+q
64.60.F-
Opis:
Majority-vote models on scale-free hypergraphs are investigated by means of numerical simulations with different variants of system dynamics. Hypergraphs are generalisations of ordinary graphs in which higher order of social organisation is included by introducing hyperedges corresponding to social groups, connecting more than two nodes. In the models under study, opinions of agents (two-state spins) placed in nodes are updated according to a probabilistic rule with control parameter representing social noise. The probability of a single spin flip depends on the average opinion within only one social group (hyperedge) the agent belongs to. This introduces an intermediate level of social interactions, in contrast with the case of networks, where the opinion of an agent usually depends on the average opinion of all neighbours. In all cases under consideration a second-order phase transition to a state with an uniform opinion was found as a function of the social noise, with the critical value of the control parameter and the critical exponents depending on the hypergraph topology and details of the system dynamics (node or hyperedge update).
Źródło:
Acta Physica Polonica A; 2015, 127, 3A; A-55-A-58
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure of Dense Polymer Systems Confined to a Slit
Autorzy:
Sikorski, A
Powiązania:
https://bibliotekanauki.pl/articles/2044630.pdf
Data publikacji:
2006-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.50.Ng
05.10.Ln
61.25.Hq
Opis:
The linear polymer chains were approximated as series of identical segments on a simple cubic lattice. The excluded volume was included into the model with no attractive interactions which corresponded to the good solvent conditions. The polymer chains were put into a slit formed by a pair of parallel surfaces. These walls were impenetrable for polymer segments and no other interactions between walls and chains were assumed. The models chains were studied by the means of the Monte Carlo method. The sampling algorithm was Metropolis-type and employing micromodifications of chain's conformation to sample efficiently the conformational space. The influence of the chain length, density of the polymer system, and the distance between the surfaces on the shape of macromolecules was studied. It was found that the decrease in the size of the slit and the decrease in the polymer density led to the formation of more spherical macromolecules. This is partially caused by the interpenetration of polymer chains.
Źródło:
Acta Physica Polonica A; 2006, 109, 2; 133-141
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Shape of Confined Polymer Chains
Autorzy:
Sikorski, A.
Powiązania:
https://bibliotekanauki.pl/articles/2035734.pdf
Data publikacji:
2003-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.50.Ng
05.10.Ln
61.25.Hq
Opis:
The linear polymer chains were modeled on a simple cubic lattice. The excluded volume was included into the model while the system remained athermal (no attractive interactions) which simulated the good solvent conditions. The polymer chain was located between two parallel impenetrable walls and the distance between the walls was changing. No interaction between walls and polymer segments was assumed. These models of polymer chains were simulated by the means of the Monte Carlo method. In the sampling algorithm we used the micromodifications of chain's conformations to sample efficiently the conformational space. The size of the chain did not change monotonically for all lengths under consideration (up to 800 statistical segments). For distances between the plates close to the double value of chain's radius of gyration the size of the chain approached its minimum value. It was shown that scaling of chain dimensions with its length changed from N$\text{}^{1.18}$ to N$\text{}^{1.5}$ while the distance between the walls was decreasing. The behavior of the asymmetry of the chain was found to be analogous to that of the radius of gyration.zapisz i p
Źródło:
Acta Physica Polonica A; 2003, 103, 4; 339-347
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Finite-Element Flash Method for Measuring Thermal Conductivity of Liquid
Autorzy:
Mamczur, J.
Wasilewski, A.
Więcek, T.
Powiązania:
https://bibliotekanauki.pl/articles/1402572.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
44.05.+e
44.10.+i
07.05.Tp
02.70.Dh
02.60.Ed
Opis:
A laser beam is used to heat a portion of liquid closed in a vessel from the top of it to avoid convection. The temperature is measured at the bottom of the vessel by a laser waveguide sensor. The heating and measuring methods allow using a small amount of liquid of the order of a milliliter fraction. The heat flow through the liquid as well as the surrounding vessel and space is modeled by the finite-element method to calculate the temperature at the bottom vs. time. Thus obtained dependence is used then as a fitting function to get the liquid thermal conductivity among some other fitting parameters.
Źródło:
Acta Physica Polonica A; 2015, 128, 2; 193-195
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamics of the Exactly Solvable Spin-Electron Tetrahedral Chain
Autorzy:
Gálisová, L.
Powiązania:
https://bibliotekanauki.pl/articles/1402558.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.-a
75.10.Pq
Opis:
An exactly solvable spin-electron tetrahedral chain, where the Ising spins localized at nodal lattice sites regularly alternate with three equivalent lattice sites available for one mobile electron is considered. The system with ferromagnetic interaction between the Ising spins and electrons exhibits an enhanced magnetocaloric effect in the limit H/|J| → 0 when the entropy is very small, whereas the system with antiferromagnetic interaction between the Ising spins and electrons exhibits an enhanced magnetocaloric effect around the field H/J=1 when the entropy is sufficiently close to the value S/2N = ln[(1+√5)/2]. We study the thermodynamics of the system in these field regions.
Źródło:
Acta Physica Polonica A; 2015, 128, 2; 156-158
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enhanced magnetocaloric effect due to selective dilution in a triangular ising antiferromagnet
Autorzy:
Borovský, M.
Žukovič, M.
Powiązania:
https://bibliotekanauki.pl/articles/1054817.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.50.Ee
75.30.Sg
05.10.Ln
Opis:
We employ an effective-field theory with correlations in order to study a magnetocaloric effect on a triangular Ising antiferromagnet, which is selectively diluted by non-magnetic impurities on one of the three sublattices. Such a dilution generally relieves massive degeneracy in our system and therefore the ground-state entropy diminishes and the magnetocaloric effect weakens at low temperatures. However, at relatively higher temperatures we can observe significantly enhanced negative isothermal entropy changes for the sublattice concentration p_A=0.8.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 645-647
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mean-Field and Monte Carlo Study of a Mixed Ferro-Ferrimagnetic Ternary Alloy
Autorzy:
Dely, J.
Bobák, A.
Horváth, D.
Powiązania:
https://bibliotekanauki.pl/articles/1813809.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.10.Ln
75.10.Hk
75.50.Gg
Opis:
We present a study of the magnetic properties of a mixed ferro-ferrimag-netic ternary alloy of the type $AB_p C_{1-p}$ on a cubic lattice consisting of three different Ising spins $S_A$ =3/2, $S_B$ = 2, and $S_C$ = 5/2. We employ the mean-field approximation and Monte Carlo simulation to find the compensation temperatures of the system for selected values of the parameters in the model Hamiltonian. In particular, the relation between considered mixed ferro-ferrimagnetic model and magnetic properties of the ternary metal Prussian blue analog such as $(Fe_p^{II}Mn_{1-p}^{II})_1.5$ $[Cr^{III}(CN)_6] \cdot nH_2O$ is discussed.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 461-464
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Phase Transition in the One-Dimensional XZ Model
Autorzy:
Brzezicki, W.
Oleś, A.
Powiązania:
https://bibliotekanauki.pl/articles/1810415.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
03.67.-a
05.70.Fh
Opis:
We introduce a one-dimensional XZ model with alternating $σ_i^zσ_{i+1}^z$ and $σ_i^x σ_{i+1}^x$ interactions on even/odd bonds, interpolating between the Ising model and the quantum compass model. We present two ways of its exact solution by: (i) mapping to the quantum Ising models, and (ii) using fermions with spin 1/2. In certain cases the nearest neighbor pseudospin correlations change discontinuously at the quantum phase transition, where one finds highly degenerate ground state of the 1D compass model.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 162-164
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Hilbert Space and the Exact Solution of the Spin-Electron Double-Tetrahedral Chain
Autorzy:
Jakubczyk, D.
Gálisová, L.
Powiązania:
https://bibliotekanauki.pl/articles/1402563.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
02.20.-a
05.30.-d
75.10.Pq
05.50.+q
Opis:
We discuss an exactly solvable double-tetrahedral chain, in which the localized Ising spins regularly alternate with triangular clusters - each available for one mobile electron. We give an exact solution for the considered hybrid system by the construction of the N-th tensor power of the Fourier transformation and using the generalized decoration-iteration mapping tranformation.
Źródło:
Acta Physica Polonica A; 2015, 128, 2; 173-175
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chaotic Dynamics of a Linear Chain of Periodically Stimulated Neurons with Random Synaptic Connections
Autorzy:
Kosiński, R. A.
Krawiecki, A.
Sukiennicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/2027444.pdf
Data publikacji:
2001-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.10.+e
05.45.-a
Opis:
Dynamics of a neural network in the form of a linear chain of artificial neurons S$\text{}_{i}$∈(-1,1) influenced by an external sinusoidal stimulation is investigated as a function of the range k of synaptic connections with random values. Time evolution of the network is periodic for small k, however, clusters of neurons oscillating with a triple period of external stimulation, with quasiperiodic or with chaotic time evolution may occur. For increasing k the number and width of the chaotic clusters increase and for k >4 the chaotic motion occurs in the whole network. A route to chaos in the considered system is discussed.
Źródło:
Acta Physica Polonica A; 2001, 100, 1; 89-99
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exergy analysis of a combined power and cooling cycle
Autorzy:
Karaalı, R.
Powiązania:
https://bibliotekanauki.pl/articles/1070364.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
88.05.Sv
88.10.cn
88.20.tf
Opis:
Ammonia-water power cycles are important for efficient utilization of low temperature heat sources such as geothermal, solar, waste heat sources, etc. For some special conditions ammonia-water power cycle is an important and economical option. This paper presents an exergetic analysis of a combined power and cooling cycle that uses ammonia-water mixture as working fluid. Such cycles, use solar or geothermal energy or waste heat energy from a conventional power cycle. Ammonia-water power cycle can be used as independent cycles to provide power output and cooling. For a range (25-55 Bar) of boiler pressure the performance of the combined power and cooling cycle is investigated. The exergy of the boiler is very low compared to its energy. There is a boiling process and a heat transfer process at low temperature, both of which destruct the energy given to the boiler, so that the energy efficiency is low; however the exergy efficiency is higher than the energy efficiency. Increasing the turbine inlet pressure decreases the energy and exergy efficiencies.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 209-213
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radial Distribution Function Analysis of Carbon Nanotubes
Autorzy:
Szczygielska, A.
Jabłońska, A.
Burian, A.
Dore, J. C.
Honkimaki, V.
Nagy, J. B.
Powiązania:
https://bibliotekanauki.pl/articles/2014446.pdf
Data publikacji:
2000-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.10.-i
81.05.Tp
Opis:
Wide-angle X-ray scattering studies of carbon nanotubes produced by catalytic decomposition of acetylene on a supported Co catalyst are reported. The X-ray intensities were recorded up to maximum scattering vector K$\text{}_{max}$=24Å and then Fourier transformed to real space. Yielding the radial distribution functions of good spatial resolution were analysed by the model based on fitting procedures method. Detailed analysis of the experimental data by a least-squares fitting procedure shows that the local atomic structure exhibits the expected hexagonal network with the nearest-neighbour C-C distance of 1.41Å. Investigation of stacking nature of subsequent layers suggests the structure in which adjacent layers are arranged without spatial correlations with inter-tubule spacing of about 3.4Å.
Źródło:
Acta Physica Polonica A; 2000, 98, 5; 611-617
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrochemical Method of Obtaining of Electric Current from Thermal Energy Using Graphite Electrodes
Autorzy:
Yegeubayeva, S.
Bayeshov, A.
Bayeshova, A.
Powiązania:
https://bibliotekanauki.pl/articles/1402509.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
88.05.Ec
88.10.-g
Opis:
Here we present the possibility of using the electrochemical processes to convert solar thermal energy or geothermal energy into electricity, based on fundamental and experimental research. Laboratory setup for converting thermal energy into electrical energy is the glass electrolyzer consisting of two electrode spaces connected with electrolytic bridge. The influence of the temperature difference between the electrode formation spaces on the EMF and the short circuit current (SCC) between graphite electrodes in aqueous solutions was studied. In solution of 100 g/l of sodium hydroxide the values of the EMF, SCC and oxidation-reduction potential are 80.0 mV, 44.1 μA and 95 mV, respectively. These values are substantially higher than those of the acidic and neutral solutions. This is due to the fact that in the alkaline solution the oxidation of hydroquinone, 1,4-benzoquinone is reversible and provides good reproducible electrode potential, which depends on the pH. The coefficient of conversion of thermal energy into electrical energy is 1.14 mV/deg.
Źródło:
Acta Physica Polonica A; 2015, 128, 2B; B-455-B-457
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chaotic Dynamics of Periodically Driven Domain Walls in Magnetic Garnet Films
Autorzy:
Kosiński, R. A.
Sukiennicki, A.
Powiązania:
https://bibliotekanauki.pl/articles/1945374.pdf
Data publikacji:
1996-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.+b
75.10.Hk
75.60.Ch
Opis:
The motion of domain walls in thin garnet films was investigated numerically using Slonczewski's equations of wall motion for the case of periodic drive field. The type of the wall motion was analyzed by observation of phase trajectories and spatio-temporal diagrams. It was found that depending on the period and amplitude of the drive field the motion of the wall is periodic or chaotic, reflecting the character of the dynamical processes connected with horizontal Bloch lines in the wall.
Źródło:
Acta Physica Polonica A; 1996, 89, 4; 495-501
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rectification of Brownian Particles with Oscillating Radii in Asymmetric Corrugated Channels
Autorzy:
Glavey, R.
Savel'ev, S.
Powiązania:
https://bibliotekanauki.pl/articles/1402559.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.40.-a
87.10.Mn
Opis:
Transport of a Brownian particle with an oscillating radius freely diffusing in an asymmetric corrugated channel was simulated over a range of driving forces for a series of temperatures and angular frequencies of radial oscillation. It was observed that there was a strong influence of self-oscillation frequency on the average particle velocity. This effect can be used to control rectification of biologically active particles as well as for their separation according to their activity, for instance in the separation of living and dead cells.
Źródło:
Acta Physica Polonica A; 2015, 128, 2; 159-162
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetisation and Entropy of a One-Dimensional±J Ising Model in a Uniform Magnetic Field
Autorzy:
Błaszyk, M.
Powiązania:
https://bibliotekanauki.pl/articles/2047254.pdf
Data publikacji:
2007-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Nr
75.50.Lk
Opis:
An approximation scheme related to the averaging procedure over finite fragments of the lattice was proposed. The magnetisation and entropy were calculated numerically. The correctness of this approximation scheme was analysed against the magnetic field and temperature.
Źródło:
Acta Physica Polonica A; 2007, 111, 2; 191-200
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chaotic Dynamics of Domain Walls in Magnetic Garnet Films with In-Plane Fields
Autorzy:
Sukiennicki, A.
Kosiński, R. A.
Powiązania:
https://bibliotekanauki.pl/articles/1933423.pdf
Data publikacji:
1995-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.+b
75.10.Hk
75.60.Ch
Opis:
Chaotic dynamics and routes to chaos of domain walls in magnetic bubble garnet materials in the presence of in-plane fields were investigated numerically using Slonczewski's equations of motion. Connection between the structure of the wall and the character of the attractor was found. The in-plane field can play a role of the factor controlling chaos.
Źródło:
Acta Physica Polonica A; 1995, 87, 6; 933-938
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ground-State Energy of a Frustrated ±J Ising Model on a Strip of Squares
Autorzy:
Błaszyk, M.
Fechner, B.
Powiązania:
https://bibliotekanauki.pl/articles/2013704.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Nr
75.50.Lk
Opis:
We investigated a ±J Ising model on an infinite strip of squares of the width of one and two bonds with a random distribution of ferro- and antiferromagnetic exchange interactions. The exact ground-state energy as a function of the concentration of antiferromagnetic bonds was derived and its singular points in the complex-plane were found.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 855-858
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetization and Susceptibility of a Diluted Triangular Ising Antiferromagnet in a Field
Autorzy:
Borovský, M.
Žukovič, M.
Bobák, A.
Powiązania:
https://bibliotekanauki.pl/articles/1199489.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.De
75.10.Hk
75.50.Ee
Opis:
Within the framework of the effective-field theory with correlations we investigate effects of an external magnetic field and random site dilution on basic thermodynamic quantities, such as the magnetization and the magnetic susceptibility, on the geometrically frustrated triangular lattice Ising antiferromagnet. Behavior of these quantities is presented in the temperature-field parameter space for selected mild degrees of dilution. It is found that, besides the anomalies associated with phase transitions from the ferrimagnetic to the paramagnetic state, in certain regions of the parameter space these functions display some more anomalies and peculiarities, as a result of joint effects of the geometrical frustration, magnetic dilution, thermal fluctuations and the applied magnetic field.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 16-17
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time Evolution of the Magnetic Chains with Uniaxial Anisotropy
Autorzy:
Woźniak, D.
Drzewiński, A.
Kamieniarz, G.
Powiązania:
https://bibliotekanauki.pl/articles/1385537.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
76.60.Es
05.30.-d
Opis:
In the framework of the matrix product states representation the effect of the single-ion anisotropy on the time evolution of the initial state after a sudden quench of the local magnetic field has been investigated. The overlap of the initial and time-evolved states, so called the Loschmidt echo, magnetization profiles and correlation functions are presented.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 333-335
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Route to Chaos for Domain Walls with a Model of Stray Field
Autorzy:
Sukiennicki, A.
Kosiński, R. A.
Żebrowski, J. J.
Powiązania:
https://bibliotekanauki.pl/articles/1931285.pdf
Data publikacji:
1994-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.+b
75.10.Hk
75.60.Ch
Opis:
The route to chaos of domain wall in thin magnetic film, which is described by Słonczewski's equations of motion, is analyzed numerically. Hagedorn's model of surface stray field is applied. Ranges of periodic and chaotic wall motion as a function of constant in time, drive field are found. Comparison of results with those obtained for Hubert's model of the stray field is made.
Źródło:
Acta Physica Polonica A; 1994, 85, 5; 791-796
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Low-Temperature Properties of Ising Antiferromagnet on a Stacked Triangular Lattice
Autorzy:
Žukovič, M.
Mižišin, L.
Bobák, A.
Powiązania:
https://bibliotekanauki.pl/articles/1199547.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.De
75.10.Hk
75.50.Ee
Opis:
An Ising antiferromagnet on a stacked triangular lattice in zero field is studied by Monte Carlo simulations, focusing on the character of the low-temperature phase and the effect of the relative strength of the exchange interaction in the stacking direction α. Our results support the presence of the 3D Wannier phase, with the sublattice magnetization structure (m, -m, 0) and power-law decaying m with the lattice size. The extent of this low-temperature phase shrinks with decreasing α, however, it appears even at very low values if it is accessed from higher temperatures by sufficiently slow cooling.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 40-41
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recurrence Quantification Analysis of Lorenz Model Periodically Modulated at the Onset of Chaos
Autorzy:
Babinec, P.
Krafčík, A.
Powiązania:
https://bibliotekanauki.pl/articles/1493371.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.40.-a
87.10.Mn
43.60.+d
43.71.+m
Opis:
Plots and quantitative measures obtained from recurrence quantification analysis - recurrence rate, determinism, entropy, and trapping time, were used for the sensitive detection of transitions from laminar (regular) to turbulent (chaotic) phases in the Lorenz model periodically modulated at the onset of chaos.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 368-370
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single Particle Excitation Spectrum of a Proximized Quantum Dot: The Flow Equation Study
Autorzy:
Zapalska, M.
Domański, T.
Powiązania:
https://bibliotekanauki.pl/articles/1374179.pdf
Data publikacji:
2014-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.10.Cc
71.27.+a
72.15.Qm
74.45.+c
Opis:
We study the in-gap states of a quantum dot hybridized with the metallic and superconducting reservoirs applying the continuous unitary transformation to the Anderson-type Hamiltonian. We derive the set of flow equations and analyse the effective single particle excitation spectrum of the correlated quantum dot in presence of the induced electron pairing.
Źródło:
Acta Physica Polonica A; 2014, 126, 4a; A-137-A-140
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Possible Long Time Tails in Current-Current Correlation Function for Two-Dimensional Electron Gas in Random Magnetic Field
Autorzy:
Łusakowski, A.
Turski, Ł. A.
Powiązania:
https://bibliotekanauki.pl/articles/1968462.pdf
Data publikacji:
1997-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.60.+w
72.10.-d
Opis:
We consider a two-dimensional degenerate electron gas in the presence of perpendicular random magnetic field. The magnetic field disorder which is assumed to be Gaussian is characterized by two parameters. The first is proportional to the amplitude of local magnetic field fluctuations. The second one characterizes the disorder on the longer scale - we call it the screening length. Using the Kubo formula for the conductivity we have found a class of diagrams which leads to the long time tails in the current-current correlation function. For short times in comparison with the diffusion time corresponding to the screening length this function behaves like logarithm of time, for longer times it decays like t$\text{}^{-1}$ which of course brings into question the diffusive character of the behavior of the charged particle in random magnetic field widely assumed in the literature.
Źródło:
Acta Physica Polonica A; 1997, 92, 6; 1109-1115
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simple Quantitative Analysis of Spatio-Temporal Diagrams for Domain Wall Dynamics
Autorzy:
Kosiński, R. A.
Stępień, R.
Powiązania:
https://bibliotekanauki.pl/articles/1932111.pdf
Data publikacji:
1995-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.+b
75.10.Hk
75.60.Ch
Opis:
A quantitative analysis of spatio-temporal diagrams, which describe the dynamics of a chosen, spatially extended dynamic system (a domain wall in a thin magnetic garnet film) is presented. Two quantifiers characterizing such diagrams - a correlation function and power spectrum density function - were calculated using solutions of equations of motion. It was found that introducing these quantifiers to the analysis of spatio-temporal diagrams enables one to effectively characterize the type and the properties of motion of the considered system.
Źródło:
Acta Physica Polonica A; 1995, 87, 3; 575-583
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bayesian Forecasting of the Discounted Payoff of Options on WIG20 Index in Discrete-Time SV Models
Autorzy:
Pajor, A.
Powiązania:
https://bibliotekanauki.pl/articles/1812219.pdf
Data publikacji:
2008-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
89.65.Gh
05.10.Gg
Opis:
In this paper the bivariate stochastic volatility models (with stochastic volatility and stochastic interest rate) and the univariate fat-tailed and correlated stochastic volatility model (with stochastic volatility and constant interest rate) are used in the Bayesian forecasting of the payoff of European call options. The basic instrument is the WIG20 index. The predictive distribution of the discounted payoff is induced by the predictive distribution of the growth rate of the WIG20 index and the WIBOR1m interest rate. The Bayesian inference about the volatilities and the predictive distribution of the discounted payoff function is based on the joint posterior distribution of the latent variables, the parameters, and the predictive distribution of future observations, which we simulate via Markov chain Monte Carlo methods (the Metropolis-Hastings algorithm is used within the Gibbs sampler). The results show that allowing interest rate to be stochastic does not significantly improve forecasting performance of the discounted payoff. The predictive distributions of the discounted payoff are characterised by huge dispersion and thick tails, thus uncertainty about the future value of the payoff was ex-ante very big.
Źródło:
Acta Physica Polonica A; 2008, 114, 3; 507-516
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of EGNOS-Augmented GPS Receiver Positioning Accuracy
Autorzy:
Skorkowski, A.
Topór-Kamiński, T.
Powiązania:
https://bibliotekanauki.pl/articles/1417964.pdf
Data publikacji:
2012-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.10.Pr
89.20.Hh
06.20.Dk
07.05.Hd
Opis:
This study presents the operation basis of GPS global positioning system and augmentation systems used to increase positioning accuracy. Furthermore, selected measurement results for an EGNOS-augmented GPS receiver positioning are included along with an analysis of GIS measurements accuracy, performed using differential corrections. This analysis takes into consideration the impact of the number of measurement series and satellite constellation on the accuracy of positioning achieved in praxis using the EGNOS system.
Źródło:
Acta Physica Polonica A; 2012, 122, 5; 821-824
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Thermoluminescence of CVD Diamond
Autorzy:
Karczmarska, A.
Mitura-Nowak, M.
Nowak, T.
Marszałek, M.
Powiązania:
https://bibliotekanauki.pl/articles/1490194.pdf
Data publikacji:
2012-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.10.Bk
81.05.ug
78.60.Kn
Opis:
This work reports some thermoluminescent properties of chemical vapour deposition diamond film grown by 5 kW microwave assisted plasma chemical vapour deposition. The 2" diamond sample with the thickness of 32 μm was exposed to gamma radiation in the dose range 0.6-55 Gy. The thermoluminescent glow curve of diamond sample displayed a peak with the maximum centered at 240°C. The linearity of the detector response in the range of 10-55 Gy was observed. The bleaching effect, seen as fading of the thermoluminescent signal when the device was exposed to light in the visible range, was also noticed. Two-dimensional dose distribution was measured using 2D thermoluminescent reader equipped with a sensitive 640 × 480 pixels charge coupled device camera. The surface morphology of the diamond film was observed with scanning electron microscope and atomic force microscope. The grain size was estimated as about 15 μm. The Raman spectroscopy was used to characterize phase purity. The width and position of the diamond Raman band around 1332 $cm^{-1}$ indicated that the coating is crystalline and of good quality. It is concluded that good quality chemical vapour deposition diamond coating could be promising material for thermoluminescent dosimetry.
Źródło:
Acta Physica Polonica A; 2012, 121, 2; 510-513
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Growth Conditions and Doping on Physical Properties of Gallium Antimonide Single Crystals
Autorzy:
Mirowska, A.
Orłowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/1409657.pdf
Data publikacji:
2012-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Ea
81.10.Fq
81.10.-h
81.10.St
72.80.Ey
71.55.Eq
61.72.uj
Opis:
Gallium antimonide (GaSb) single crystals were grown by modified Czochralski method integrated with in situ synthesis in a flowing atmosphere of pure hydrogen. The influence of charge material purity as well as other technological parameters on GaSb crystals quality was investigated. High purity undoped GaSb single crystals were grown with residual acceptors concentration < 1.4 × $10^{17} cm^{-3}$ and high mobility ≈ 690 $cm^2$/Vs (at 300 K). P-type GaSb crystals were doped with silicon (carrier concentration up to 2 × $10^{19} cm^{-3}$) and with zinc (up to 1 × $10^{19} cm^{-3}$). Tellurium doped n-type GaSb single crystals were obtained with concentration up to 2 × $10^{18} cm^{-3}$. Electrical parameters were investigated by the Hall measurements (300 K and 77 K). Temperature dependent Hall measurements (10 ÷ 300 K) were used to compare the quality of undoped GaSb (obtained from Sb of different purity). Dopant concentration was estimated by glow discharge mass spectroscopy analysis. Axial and radial distribution of carrier concentration were investigated especially for Te-doped crystals (low segregation coefficient of Te in GaSb). Great contribution of compensation and self-compensation mechanisms is shown especially for the beginning part of grown crystals and for low Te-doping level. Radial distribution of physical properties for crystals grown in 〈100〉 direction is not axisymmetrical especially for doped GaSb crystals.
Źródło:
Acta Physica Polonica A; 2012, 122, 6; 1111-1114
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exact Ground States of Frustrated Spin-1 Ising-Heisenberg and Heisenberg Ladders in a Magnetic Field
Autorzy:
Strečka, J.
Michaud, F.
Mila, F.
Powiązania:
https://bibliotekanauki.pl/articles/1199503.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Jm
75.10.Kt
75.60.Ej
Opis:
Ground states of the frustrated spin-1 Ising-Heisenberg two-leg ladder with Heisenberg intra-rung coupling and only Ising interaction along legs and diagonals are rigorously found by taking advantage of local conservation of the total spin on each rung. The constructed ground-state phase diagram of the frustrated spin-1 Ising-Heisenberg ladder is then compared with the analogous phase diagram of the fully quantum spin-1 Heisenberg two-leg ladder obtained by density matrix renormalization group (DMRG) calculations. Both investigated spin models exhibit quite similar magnetization scenarios, which involve intermediate plateaux at one-quarter, one-half and three-quarters of the saturation magnetization.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 24-25
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solubility and Segregation of Co in CdTe-Based Ternary and Quaternary Alloys
Autorzy:
Miotkowska, S.
Dynowska, E.
Miotkowski, I.
Alawadhi, H.
Lewicki, A.
Metcalf, P. A.
Ramdas, A.
Powiązania:
https://bibliotekanauki.pl/articles/2030667.pdf
Data publikacji:
2002-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Dz
81.10.-h
Opis:
Single crystals of Cd$\text{}_{1-x}$Co$\text{}_{x}$Te and Cd$\text{}_{1-x-y}$Co$\text{}_{x}$Mn$\text{}_{y}$Te are characterized with X-ray powder diffraction and electron microprobe to establish compositional dependence of the lattice parameters and deduce Co solubility limit. The experimental compositional profiles are examined on specimens taken from various locations of ingots along their longitudinal axes and compared with normal freezing distributions. The values of Co segregation coefficient are analyzed for both ternary and quaternary alloys in terms of normal freezing mode.
Źródło:
Acta Physica Polonica A; 2002, 101, 5; 735-742
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metastable Magnetic Structures in the Blume-Capel Model
Autorzy:
Kułakowski, K.
Antoniuk, M.
Del Moral, A.
Gawroński, P.
Powiązania:
https://bibliotekanauki.pl/articles/2013716.pdf
Data publikacji:
2000-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.Fh
75.10.Hk
75.30.Kz
Opis:
We discuss a first-order phase transition from non-magnetic to magnetic phase at T=0. New results are presented on a spontaneously formed magnetic phase and its energy in the C15 atomic structure, in the presence of the antiferromagnetic interaction. A dynamic phase diagram is constructed for the phase transition. The results are discussed in the context of the pressure-driven phase transition, which was observed experimentally in YMn$\text{}_{2}$.
Źródło:
Acta Physica Polonica A; 2000, 97, 5; 893-896
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In Situ Investigation of Microstructure Evolution during Solidification of Mg10CaxGd (x=5, 10, 20) Alloys
Autorzy:
Mendis, C.
Tolnai, D.
Stark, A.
Schell, N.
Kainer, K.
Hort, N.
Powiązania:
https://bibliotekanauki.pl/articles/1402097.pdf
Data publikacji:
2015-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
81.30.Fb
Opis:
Mg-Ca-Gd based alloys are investigated as a potential alloy for degradable biomaterials with some promising results. In this investigation the Mg10CaxGd (x=5, 10, 20) were investigated with synchrotron radiation X-ray diffraction during solidification to follow the phase evolution at two different cooling rates at 5 and $50 K \text{min}^{-1}$. All three alloys show formation of α -Mg followed by Mg₂Ca phase, while only Mg10Ca20Gd alloy contained Mg₅Gd phase during solidification. During cooling α -Mg was first observed between 628 and 632°C at a cooling rate of $5 K \text{min}^{-1}$ while this decreased to 620-628°C with the increase in cooling rate to $50 K \text{min}^{-1}$. The change in cooling rate from $5$ to $50 K \text{min}^{-1}$ did not change the types of intermetallic phases observed but resulted in suppressing temperatures at which the intermetallic phases were first detected.
Źródło:
Acta Physica Polonica A; 2015, 128, 4; 606-610
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Effect of a Random Crystal-Field on the Mixed Ising Spins (1/2, 3/2)
Autorzy:
Bahmad, L.
Benayad, M.
Benyoussef, A.
El Kenz, A.
Powiązania:
https://bibliotekanauki.pl/articles/1504480.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Hk
75.50.Gg
Opis:
We study the magnetic properties of a mixed Ising ferrimagnetic system, in which the two interacting sublattices have spins σ,(±1/2) and spins S,(±3/2,±1/2) in the presence of a random crystal field, with the mean field approach. The results obtained, using mean field approach and Monte Carlo simulation, show the appearance of a new ferrimagnetic phase, namely the partly ferrimagnetic phase ($m_{σ}$ = -1/2 , $m_{S}$ = +1). Consequently, three topologically different types of phase diagrams have been given by mean field approach. The effect of increasing the exchange interaction parameter J, at very low temperature is also investigated.
Źródło:
Acta Physica Polonica A; 2011, 119, 6; 740-746
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo simulations of resistive plate chamber for 0.511 MeV photon with FLUKA
Autorzy:
Demir, N.
Aydın, A.
Powiązania:
https://bibliotekanauki.pl/articles/1070435.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
29.40.Cs
29.40.Gx
05.10.Ln
Opis:
We report the simulation results of resistive plate chamber for 0.511 MeV photons using FLUKA code. The efficiency of resistive plate chamber is directly related to the number of electrons produced in the gas gap. Therefore, the type of converter materials and thickness are important parameters for resistive plate chamber detection performance. In this work, the FLUKA based simulations for parallel and isotropic photons were operated for detection efficiency by choosing different converter materials and thicknesses.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 466-468
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intrinsic Rhythmic Fluctuation of Membrane Voltage Evoked by Membrane Noise in the Hodgkin-Huxley System
Autorzy:
Kuang, S.
Wang, J.
Zeng, T.
Powiązania:
https://bibliotekanauki.pl/articles/1538607.pdf
Data publikacji:
2010-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.45.-a
87.10.-e
Opis:
We study the influence of membrane noise on the fluctuations of membrane voltage in the Hodgkin-Huxley neuronal system for the giant axon of squids. We find that the resting potentials of membrane patches in the absence of any external stimulus, exhibit apparent rhythmic fluctuation behaviors. The intrinsic fluctuation frequencies of membrane voltage, due to channel noise, thermal noise, or both, roughly share the same frequency ranges, despite that the fluctuations arisen from the former noise are overwhelmingly larger in amplitude than that from the latter. We also show that the rhythmic fluctuations can help enhance the encoding of weak signals within the rhythmic frequencies ranges and thus contribute positively to the information processing in the nervous system.
Źródło:
Acta Physica Polonica A; 2010, 117, 3; 435-438
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Transitions in a Coupled Electron and Spin Model on the Shastry-Sutherland Lattice
Autorzy:
Farkašovský, P.
Čenčariková, H.
Powiązania:
https://bibliotekanauki.pl/articles/1366499.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.-b
75.40.Mg
05.70.Fh
Opis:
The thermodynamics of a simple electron-spin model proposed recently for a description of magnetization processes in rare-earth tetraborides is studied numerically by the canonical Monte Carlo method in two-dimensions. The model is based on the coexistence of two subsystems, and namely, the spin subsystem described by the Ising model and the electronic subsystem described by the free-electron model on the Shastry-Sutherland lattice (SSL). Moreover, both subsystems are coupled by the anisotropic spin-dependent interaction of the Ising type. At T=0 the system exhibits the magnetization plateau (MP) at m/$m_s$=1/2, 1/3, 1/5, 1/7, 1/9 and 1/11 of the saturated spin magnetization $m_s$. For the largest phases corresponding to m/$m_s$=0, 1/3 and 1/2 we have examined the nature of the phase transitions from the low-temperature ordered phase (LTOP) to the high-temperature disordered phase (HTDP). It is shown that all phases persist also at finite temperatures (up to the critical temperature $T_c$) and that the phase transition at the critical point is of the second order for the m/$m_s$=0 phase and of the first order for the m/$m_s$=1/3 and 1/2 phases.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 44-45
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-Dimensional Ising Model with Competing Interactions as a Model for Interacting π-Rings
Autorzy:
O'Hare, A.
Kusmartsev, F.
Kugel, K.
Powiązania:
https://bibliotekanauki.pl/articles/1810411.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Hk
74.81.Fa
03.67.Lx
Opis:
We investigate the Ising model on a square lattice with antiferromagnetic exchange between nearest and next-nearest neighbors and show that at low temperatures stripe-like and droplet-like superstructures appear. We show that the competing interactions introduce a strong frustration that could plausibly describe the systems with dipole-dipole type interactions and pay particular attention to arrays of interacting Josephson π-rings.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 150-152
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Research on Nitinol Alloy Material Fatigue Behavior Analysis of Cardiovascular Stent in Medical Engineering
Autorzy:
Karaçalı, Ö.
Powiązania:
https://bibliotekanauki.pl/articles/1194117.pdf
Data publikacji:
2015-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.40.Np
81.70.Bt
81.05.Bx
87.10.Kn
Opis:
Biocompatible cardiovascular stents are small cylindrical support structures introduced into the stenosed arteries to reopen the lumen and to restore blood flow in treating heart disease, which have revolutionized interventional cardiology. Cardiovascular stent designers are confronted with two basic requirements, such as an "infinite" life and the "thinnest" wires. Pulsatile pressure, repetitive mechanical forces, within the coronary artery may result in stent fatigue and fracture after stent implantation, particularly in patients with complex coronary disease. This research describes the simulation analysis of cardiovascular stents, to provide designers with estimates of their in vivo structural behavior and fatigue properties. Stent material failure or device fatigue remains major concern for stent manufactures and researchers. The objective of this research was to simulate the mechanical behavior of the stent using finite element method. A finite element analysis (FEA) of cardiovascular stent under fatigue cyclic loading conditions is presented. Commercial software was employed to study the fatigue performance of nitinol alloy materials in new stent systems. The effects of deployment, and static cyclic pressure loading on cardiovascular stent fatigue life were simulated and analyzed for nitinol alloy material. The investigation results displayed a significant correlation between material combinations, stent loading, and fatigue behavior.
Źródło:
Acta Physica Polonica A; 2015, 127, 4; 1167-1169
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Elastic Properties and Phase Transitions in Some Alkali Halides Using Interatomic Potential Model
Autorzy:
Yazar, H. R.
Powiązania:
https://bibliotekanauki.pl/articles/2046838.pdf
Data publikacji:
2006-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.55.Fv
05.70.-a
61.50.Ks
64.10.+h
Opis:
We have predicted the phase transition pressure in some alkali halides using an interatomic potential approach based on rigid ion model. This potential form represents the composite form of the inverse power dependence and exponential dependence of the repulsive energy on interionic distance. Some thermoelastic properties such as second order elastic constants have been calculated using the same potential. The phase transition pressures (28.69 and 2.4 GPa) obtained by us for two alkali halides (NaCl and KCl) are in closer agreement with their corresponding experimental data (29.0 and 2.0 GPa). This approach is promising with respect to prediction of the phase transition pressure of other alkali halides as well.
Źródło:
Acta Physica Polonica A; 2006, 109, 6; 743-751
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
ESR Spectroscopy of Graphene with Adsorbed NaCl Particles
Autorzy:
Karpierz, E.
Drabińska, A.
Bożek, R.
Kaźmierczak, P.
Wysmołek, A
Kamińska, M
Strupiński, W.
Powiązania:
https://bibliotekanauki.pl/articles/1376214.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.ue
72.10.Fk
78.67.Wj
72.80.Vp
Opis:
Due to its peculiar properties graphene is a good candidate for sensor materials. Therefore, it is important to study influence of different fluids on graphene layer. The presented studies showed pinning of NaCl microcrystals to graphene surface after immersing graphene in NaCl solution and subsequent careful rinsing with distilled water. The atomic force microscopy images revealed presence of many NaCl-related structures over 100 nm high on graphene surface. The electron spin resonance spectrum for magnetic field perpendicular to the graphene layer consisted of several lines originating from NaCl. The pinning of NaCl microcrystals resulted in increase of electron scattering, as confirmed by the Raman spectroscopy (the increase of intensity of D and D' bands) and weak localization measurement (the decrease of coherence length).
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1187-1189
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of heat insulation performance of hollow clay bricks filled with perlite
Autorzy:
Arıcı, M.
Yılmaz, B.
Karabay, H.
Powiązania:
https://bibliotekanauki.pl/articles/1068608.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
88.05.Sv
44.10.+i
44.25.+f
44.40.+a
Opis:
In this study, the possibility of enhancing heat insulation performance of hollow bricks by filling the cavities with perlite is investigated. A conjugate heat transfer by conduction, convection and radiation in different hollow bricks are analyzed numerically to assess their thermal performance. Calculations are performed for three scenarios for each type of hollow brick: (i) cavities are filled with air, (ii) half of the cavities are filled with perlite while the other half is filled with air, (iii) all cavities are filled with perlite. The benefit of filling cavities with perlite is justified quantitatively for each investigated hollow brick type. It is concluded that the enhancement in insulation performance can be up to 15.6% and 27.5% for half-perlite and full-perlite cases, respectively, depending on the brick type.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 266-268
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Material Fatigue Research for Zirconia Ceramic Dental Implant: a Comparative Laboratory and Simulation Study in Dentistry
Autorzy:
Karaçalı, Ö.
Powiązania:
https://bibliotekanauki.pl/articles/1401326.pdf
Data publikacji:
2015-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.40.Np
87.10.Kn
81.05.Mh
81.70.Bt
Opis:
This research focuses on the biocompatible zirconia ceramic (ZrO₂) material and load behavior causing fatigue on the surface of the dental implant in dentistry. Fatigue fracture and wear have been identified as some of the major problems associated with implant loosening, stress-shielding and ultimate implant failure. A static and cyclic fatigue testing of ceramic dental implant in laboratory conditions for this investigation were carried out according to the ISO protocol 14801 under worst-case conditions. A finite element analysis (FEA) of dental implant with accurate geometry and material properties were developed to make realistic investigations on biocompatibility of the implant biomaterial properties and mechanical fatigue behavior of new dental implant comparing Von-Mises criteria and maximum stress levels. The comparison of calculated fatigue life simulation data of and experimental data for the biocompatible zirconia ceramic dental implants is presented. As a conclusion zirconium implant exceeded the established values for maximum incisal bite forces reported in the literature and and also shows better performance than titanium implant material. The results of fatigue of biocompatible zirconia analysis are helpful for implant biomaterial selection and design for clinical interest in dentistry.
Źródło:
Acta Physica Polonica A; 2015, 127, 4; 1195-1198
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relaxation dynamics in the spin-1 Heisenberg antiferromagnetic chain after a quantum quench of the uniaxial anisotropy
Autorzy:
Woźniak, D.
Drzewiński, A.
Kamieniarz, G.
Powiązania:
https://bibliotekanauki.pl/articles/1058535.pdf
Data publikacji:
2016-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.10.Jm
76.60.Es
05.30.-d
75.30.Gw
Opis:
In the framework of the matrix product state representation the effect of a sudden turning on of the uniaxial anisotropy on the time evolution of the Haldane state has been investigated. Depending on the value of the uniaxial anisotropy parameter, the calculations were derived within (or outside) the region where the Haldane gap survives. An exact expression for the time evolution of the Loschmidt echo has been derived and, moreover, its collapse and revival behaviour was captured. In addition, the non-local order parameter of a time evolving state was tracked, revealing two types of relaxations.
Źródło:
Acta Physica Polonica A; 2016, 130, 6; 1395-1400
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formation of Uniform Germanium Islands on Silicon Substrate Using Nickel as Catalyst by Thermal Evaporation Method
Autorzy:
Jumidali, M.
Hashim, M.
Abdul Aziz, A.
Abd Rahim, A.
Powiązania:
https://bibliotekanauki.pl/articles/1193093.pdf
Data publikacji:
2015-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Ea
81.10.Bk
81.15.-z
Opis:
Uniform germanium islands (GIs) were grown on Si (100) using a nickel layer as catalyst through the physical vapor deposition of germanium (Ge) powder at 1000°C at different deposition times. Prior to the deposition of Ge layer, nickel (Ni) catalyst was deposited on silicon substrates via radio frequency magnetron sputtering technique. Scanning electron microscopy results showed that the increase in deposition time resulted in a variation in surface morphology. Energy dispersive X-ray spectrometer analysis found that the GI samples composed of Ni element indicating the role of Ni in uniform Ge islands formation. The X-ray diffraction pattern spectra revealed that the GIs exhibited a Ge cubic structure and the intensity of Ge peaks varies with deposition time. In-plane strain indicated that the strain caused by the substrate is tensile and changed to compressive strain at the longer deposition time. The Raman spectra exhibited a red shift in the Ge-Ge peak, compared with the bulk Ge, as a result of compressive strain of the GIs. Fourier transform infrared spectrum analysis also indicated that the optical band gap Eg values of GIs can be varied by deposition time.
Źródło:
Acta Physica Polonica A; 2015, 127, 4; 1068-1071
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo Study of a Spin-3/2 Blume-Emery-Griffiths Model on a Honeycomb Lattice
Autorzy:
Žukovič, M.
Jaščur, M.
Powiązania:
https://bibliotekanauki.pl/articles/1199541.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.De
75.10.Hk
75.30.Kz
75.50.Lk
Opis:
We study the phase diagram of the spin-3/2 Blume-Emery-Griffiths model on a honeycomb lattice by Monte Carlo simulations in order to verify the presence of some peculiar features predicted by the effective field theory (EFT) with correlations. The locations of the order-disorder phase boundaries are estimated from thermal variations of the magnetic susceptibility curves. It is found that for positive values of the biquadratic interactions the critical boundary shows a discontinuous character as a function of the single-ion anisotropy strength, in line with the EFT expectations. However, for negative values of the biquadratic interactions the step-like variation of the critical frontier predicted by EFT was not reproduced.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 36-37
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Direction of the c-Axis of $L1_0$ FePt Thin Films with the MÖssbauer Spectroscopy
Autorzy:
Laenens, B.
Almeida, F.
Vantomme, A.
Meersschaut, J.
Powiązania:
https://bibliotekanauki.pl/articles/1814040.pdf
Data publikacji:
2007-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.Qr
68.55.-a
81.15.-z
Opis:
The continued growth of storage capacity requires new innovations in recording media and in particular, in magnetic nanostructures. FePt thin films in the $L1_0$-phase are interesting candidates for high-density magnetic recording media due to their large magnetocrystalline anisotropy. In the present work, we investigated the magnetic and structural properties of FePt thin films directly grown on MgO(110) with molecular beam epitaxy. The purpose was to gain insight in the correlation between the magnetization process and the morphology of the FePt thin films. We introduce conversion electron MÖssbauer spectroscopy to derive the direction of the easy magnetization axis with respect to the substrate. The results are compared to the characterization performed with high angle X-ray diffraction.
Źródło:
Acta Physica Polonica A; 2007, 112, 6; 1313-1318
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication, Structural Characterization and Optical Properties of the Flower-Like ZnO Nanowires
Autorzy:
Feng, L.
Liu, A.
Ma, Y.
Liu, M.
Man, B.
Powiązania:
https://bibliotekanauki.pl/articles/1538755.pdf
Data publikacji:
2010-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.07.Bc
81.05.Dz
81.10.Aj
Opis:
Multipod flower-like zinc oxide (ZnO) nanowires have been successfully synthesized on Si(111) substrates using a pulsed laser deposition prepared Zn film as "self-catalyst" by the simple thermal evaporation oxidation of the metallic zinc powder at 850°C without any other catalysts or additives. The pre-deposited Zn films by pulsed laser deposition on the substrates can promote the formation of the ZnO nuclei effectively. Also it can further advance the growth of the flower-like ZnO nanowires accordingly. X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscopy, Fourier transform infrared spectrum, and photoluminescence were used to analyze the structure, morphology, composition and optical properties of the as-synthesized products. The results demonstrate that the nanowires were single crystalline with hexagonal wurzite structure, grown along the [0001] in the c-axis direction. Room temperature photoluminescence spectrum of the ZnO nanowires shows a nearband-edge ultraviolet emission (peak at ≈ 384 nm) and a deep-level green emission (peak at ≈ 513 nm). In addition, the growth mechanism of the flower-like ZnO nanowires is discussed in detail.
Źródło:
Acta Physica Polonica A; 2010, 117, 3; 512-517
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Study of Weak Ferromagnetism in 2D J$\text{}_{1}$-J$\text{}_{2}$ Heisenberg Model with Dzyaloshinskii-Moriya Interaction
Autorzy:
Voigt, A.
Richter, J.
Powiązania:
https://bibliotekanauki.pl/articles/1955526.pdf
Data publikacji:
1997-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Gw
05.50.+q
75.10.Jm
Opis:
By means of exact diagonalization we consider the groundstate of the J$\text{}_{1}$-J$\text{}_{2}$ spin 1/2 Heisenberg model with an anisotropic interaction term of Dzyaloshinskii-Moriya type. We find that a Dzyaloshinskii-Moriya interaction may create a weak ferromagnetic moment. The interplay between the quantum nature of the groundstate of the pure J$\text{}_{1}$-J$\text{}_{2}$ model and the anisotropic Dzyaloshinskii-Moriya interaction favour energetically a well-defined direction of spin alignment creating anisotropic correlations.
Źródło:
Acta Physica Polonica A; 1997, 91, 2; 371-375
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exact Diagonalization Study of an Extended Hubbard Model for a Cubic Cluster at Quarter Filling
Autorzy:
Szałowski, K.
Balcerzak, T.
Jaščur, M.
Bobák, A.
Žukovič, M.
Powiązania:
https://bibliotekanauki.pl/articles/1032794.pdf
Data publikacji:
2017-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.40.Cx
75.75.-c
75.10.Lp
71.27.+a
65.80.-g
05.70.Ce
Opis:
In the paper the thermodynamics of a cubic cluster with 8 sites at quarter filling is characterized by means of exact diagonalization technique. Particular emphasis is put on the behaviour of such response functions as specific heat and magnetic susceptibility. The system is modelled with extended Hubbard model which includes electron hopping between both first and second nearest neighbours as well as Coulombic interactions, both on-site and between nearest-neighbour sites. The importance of hopping between second nearest neighbours and Coulombic interactions between nearest neighbours for the temperature dependences of thermodynamic response functions is analysed. In particular, the predictions of the Schottky model are compared with the calculations based on the full energy spectrum.
Źródło:
Acta Physica Polonica A; 2017, 131, 4; 1012-1014
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical and Electrical Studies of Graphene Deposited on GaN Nanowires
Autorzy:
Kierdaszuk, J.
Kaźmierczak, P.
Drabińska, A.
Wysmołek, A.
Korona, K.
Kamińska, M.
Pakuła, K.
Pasternak, I.
Krajewska, A.
Żytkiewicz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1195433.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.ue
72.10.Fk
78.67.Wj
72.80.Vp
Opis:
In this paper using scanning electron microscope, contactless microwave electronic transport and the Raman spectroscopy we studied the properties of graphene deposited on GaN nanowires and compared it with the graphene deposited on GaN epilayer. The Raman micro-mapping showed that nanowires locally change the strain and the concentration of carriers in graphene. Additionally we observed that nanowires increase the intensity of the Raman spectra by more than one order of magnitude.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1087-1089
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Composite Fermion Description of the Excitations of the Paired Pfaffian Fractional Quantum Hall State
Autorzy:
Wójs, A.
Sreejith, G.
Möller, G.
Tőke, C.
Jain, J.
Powiązania:
https://bibliotekanauki.pl/articles/1492787.pdf
Data publikacji:
2011-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.43.-f
05.30.Pr
71.10.Pm
Opis:
We review the recently developed bipartite composite fermion model for the excitations of the so-called Pfaffian state, a promising model for the fractional quantum Hall effect at the Landau level filling factor ν = 5/2. In particular, we demonstrate a necessary ingredient of the non-Abelian braid statistics, namely the degeneracy of spatially indistinguishable configurations of widely separated quasiparticles.
Źródło:
Acta Physica Polonica A; 2011, 120, 5; 830-838
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lattice Parameters of Aluminium Nitride in the Range 10-291 K
Autorzy:
Paszkowicz, W.
Knapp, M.
Podsiadło, S.
Kamler, G.
Pełka, J. B.
Powiązania:
https://bibliotekanauki.pl/articles/2030706.pdf
Data publikacji:
2002-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Je
65.40.De
65.60.+a
65.40.-b
Opis:
Lattice parameters for aluminium nitride were determined using X-ray powder diffraction at a synchrotron radiation source (beamline B2, Hasylab/DESY, Hamburg) in the temperature range from 10 K to 291 K. The measurements were carried out using the Debye-Scherrer geometry. The relative change of both, a and c, on rising the temperature in the studied range (10-291 K) is about 0.03%. The results are compared with earlier laboratory data and theoretical predictions.
Źródło:
Acta Physica Polonica A; 2002, 101, 5; 781-785
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Proposal of a Cost-Saving and Risk Prevention Mechatronic System for Water Consumption Systems of Buildings
Autorzy:
Karayel, D.
Ozkan, S.
Atali, G.
Ceylan, N.
Kilic, R.
Powiązania:
https://bibliotekanauki.pl/articles/1031258.pdf
Data publikacji:
2017-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
47.62.+q
07.05.Dz
07.10.-h
Opis:
This study aims to develop an integrated control system to prevent the indoor loss of water. In general, these losses occur while using the hot water, because of forgetting to close the water batteries during the water cuts, or due to faults in washing machines, dishwashers and indoor plumbing systems. In this study, a specialized solution is developed for each type of losses. Then, the developed three subsystems were combined and transformed into an integrated system. This study shows that water losses in the housing can be prevented by using advanced technologies. There are similar systems in practice, but this study is different from the others with regard to its holistic approach, addressing all three problems together. The contribution of the system to economic and social life will be great, when water saving and environmental damage are considered.
Źródło:
Acta Physica Polonica A; 2017, 132, 3; 604-607
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of CMSX-4 single-crystalline turbine blades root by electron and X-ray diffraction methods
Autorzy:
Krawczyk, J.
Zubko, M.
Bogdanowicz, W.
Tondos, A.
Sieniawski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1058074.pdf
Data publikacji:
2016-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.10.Aj
61.72.Ff
61.05.J-
Opis:
The root of single-crystalline turbine blade made of CMSX-4 superalloy were studied. The studied blade was produced by the Bridgman technique in industrial ALD furnace at withdrawal rate of 3 mm/min. The samples for investigations were cut from the blade root parallel to the withdrawal direction. Metallographic sections of longitudinal samples planes were prepared for further investigations. The samples were analysed using scanning electron microscopy and the Laue diffraction studies. The crystal orientations in macro-scale were determined by analysis of the Laue pattern and local crystal orientations were studied by electron backscattered diffraction technique. Morphology of dendrites were examined by analysis of scanning electron microscopy macro-images. Study of subgrain structure was performed by X-ray diffraction topography. The sharp parallel contrast bands, visible on the X-ray topograms, were related with dendrite cores, arranged with the same direction. Additionally, the low angle boundaries were formed in certain samples, visible on the topograms as contrast shifts. Step changes of local crystal orientation in certain areas were observed on the electron backscattered diffraction maps. The electron backscattered diffraction crystal orientation maps were related to the misorientation visualized in topograms.
Źródło:
Acta Physica Polonica A; 2016, 130, 4; 1104-1106
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porosity of Silica Monoliths with Tailored Mesopores of Ink-Bottle Shape Determined by Nitrogen Adsorption and Positron Annihilation Lifetime Spectroscopy
Autorzy:
Sienkiewicz, A.
Kierys, A.
Gorgol, M.
Zaleski, R.
Powiązania:
https://bibliotekanauki.pl/articles/1033934.pdf
Data publikacji:
2017-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Rm
68.43.-h
81.70.-q
78.70.Bj
36.10.Dr
Opis:
The comparison of pore size distributions obtained with the use of two porosimetric methods: low temperature nitrogen sorption (LN2) and positron annihilation lifetime spectroscopy (PALS), was performed for porous silica monoliths. Four investigated samples were prepared under various synthesis conditions. Nitrogen sorption showed the presence of bottle-shaped pores in all investigated samples. In addition, it seems that the presence of methanol during synthesis influences porosity to a greater extent than organic additives. Quite good agreement between the LN2 and PALS results was observed only for the silica monolith synthesized with β-cyclodextrins as pore directing agent. The biggest discrepancy in the results obtained from these two techniques was observed for the silica gel synthesized with no additives. The origin of such discrepancies, taking into account the shape of pore size distribution and deficiencies of data analysis techniques, is discussed.
Źródło:
Acta Physica Polonica A; 2017, 132, 5; 1568-1571
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Investigation of ZnO Nanowires
Autorzy:
Martínez-Criado, G.
Hernández-Vélez, M.
Letard, I.
Cros, A.
Cantarero, A.
Mínguez-Bacho, I.
Susini, J.
Tucoulou, R.
Sans, J.
Sanz, R.
Vázquez, M.
Powiązania:
https://bibliotekanauki.pl/articles/1539044.pdf
Data publikacji:
2010-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.75.-d
61.10.Ht
78.70.En
81.05.Ea
Opis:
In this study we report the application of synchrotron X-ray fluorescence, photoluminescence and Raman scattering techniques to the analysis of the incorporation of impurities in unintentionally doped ZnO nanowires. Highly ordered one-dimensional ZnO arrays were fabricated by an oxidation process of Zn metal electrodeposited in nanoporous anodic alumina template. X-ray fluorescence data show the contribution of residual elements into the ZnO nanowires growth. A rough analytical quantification of the main light and heavy chemical contents derives impurity concentrations below 1%. The optical efficiency of ZnO nanowires is strongly affected by non-radiative centers up to temperatures as low as 100 K. The photoluminescence was found to be totally dominated by optical transitions associated with the anodic alumina template. Finally, the Raman scattering provides no evidence of local vibrational modes or secondary phases, but it shows the unambiguous signature of the ZnO hexagonal phase.
Źródło:
Acta Physica Polonica A; 2010, 117, 2; 369-373
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ordering in Triangular Lattice Ising Antiferromagnet Due to Dilution and Magnetic Field
Autorzy:
Žukovič, M.
Borovský, M.
Bobák, A.
Powiązania:
https://bibliotekanauki.pl/articles/1506982.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
64.60.De
75.10.Hk
75.30.Kz
75.50.Ee
75.50.Lk
Opis:
We study effects of an external magnetic field and random site dilution on the magnetic ordering in the geometrically frustrated triangular lattice Ising antiferromagnet by the use of an effective-field theory with correlations. In particular, we find that already a small amount of the quenched dilution locally relieves the frustration which in the presence of the external field is manifested by multiple splitting of a broad frustration-induced 1/3 magnetization plateau. Depending on the field strength, the dilution can either decrease or increase the magnetization or even change its effect from decreasing to increasing.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 740-741
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formability Evaluation of Aluminium Alloys by FLD Diagrams
Autorzy:
Petroušek, P.
Kočiško, R.
Kvačkaj, T.
Bidulský, R.
Bidulská, J.
Fedoriková, A.
Sabol, P.
Powiązania:
https://bibliotekanauki.pl/articles/1032922.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.20.Hy
62.10.+s
62.20.M-
81.05.-t
82.80.-d
Opis:
The goal of the present work is evaluated mechanical properties and forming limit diagrams of ambient rolled aluminium alloy based on AlMgSi. Forming limit diagrams are convenient and often used as a tool for the classification of the formability and the evaluation of the forming process of sheet materials. Forming limits of sheet metal are represented in the forming limit diagrams occurring by various deformation states. The most widely used type is the Keeler-Goodwin diagram. Input data got from static tensile test are important for formability evaluating of the thin sheet by mathematical simulations, such as tensile strength, yield strength, elongation, and the strain hardening exponent. The result is a consideration of the suitability of the material for stamping technology.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1344-1346
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Excess Conductivity of Y$\text{}_{0.95}$Pr$\text{}_{0.05}$Ba$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ Single Crystals
Autorzy:
Vovk, R. V.
Obolenskii, M. A.
Bondarenko, A. V.
Goulatis, I. L.
Chroneos, A.
Powiązania:
https://bibliotekanauki.pl/articles/2047236.pdf
Data publikacji:
2007-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.20.Eh
72.10.-d
74.40.+k
74.72.-h
Opis:
In this work we investigate the conductivity in the basis plane of YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ and Y$\text{}_{1-z}$Pr$\text{}_{z}$Ba$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-x}$ single crystals with a system of one-direction twin boundaries. The Pr dopants behave as efficient scattering centers of normal and fluctuating carriers. For this a slight doping with praseodymium (till z≈0.05) results in a significant narrowing of the temperature interval in which the pseudo-gap regime is realized in the ab-plane of YBaCuO single crystals.
Źródło:
Acta Physica Polonica A; 2007, 111, 1; 129-133
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PVT-Grown Single Crystals of Cd$\text{}_{1-x}$Zn$\text{}_{x}$Te (x ≤ 0.25) and ZnTe as Substrates for Epitaxy
Autorzy:
Mycielski, A.
Szadkowski, A.
Łusakowska, E.
Kowalczyk, L.
Domagała, J.
Bąk-Misiuk, J.
Wilamowski, Z.
Witkowska, B.
Powiązania:
https://bibliotekanauki.pl/articles/1991957.pdf
Data publikacji:
1998-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Dz
81.10.Bk
Opis:
The process of growth of single crystals of Cd$\text{}_{1-x}$Zn$\text{}_{x}$Te (x ≤ 0.25) and ZnTe by physical vapour transport has been optimized and the twin-free single crystals with a very good crystal structure and low density of dislocations are grown as substrates for MBE and other techniques of epitaxy. Characterization of the crystals is described.
Źródło:
Acta Physica Polonica A; 1998, 94, 3; 441-445
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical determination of casting-mold interfacial heat transfer coefficient in the high pressure die casting of A-360 aluminum alloy
Autorzy:
Koru, M.
Serçe, O.
Powiązania:
https://bibliotekanauki.pl/articles/1061546.pdf
Data publikacji:
2016-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Bx
47.11.Bc
47.27.ek
44.10.+i
Opis:
Although die casting is a near net shape manufacturing process, it mainly involves a thermal process. Therefore, in order to produce high quality parts, it is important to determine casting-mold interfacial heat transfer coefficient and heat flux. In this paper the effects of different injection parameters (second phase velocity, injection pressure, pouring and die temperature) on heat flux and interfacial heat transfer coefficient were investigated experimentally and numerically. Experiments were performed in cylindrical geometry using a cast aluminum alloy A360 against H13 steel mold. Selected injection parameters were 1.7-2.5 m/s for second phase velocity, 100-200 bar for third phase pressure, 983-1053 K for pouring temperature and 373, 433, 493, 553 K for the die temperature. These parameters were used for both non-vacuum and vacuum conditions in the cavity of the mold. The effects of the application under vacuum conditions were also studied. Temperatures were measured as functions of time, using 18 thermocouples, which were mounted at different depths of casting and mold material. Measured and calculated temperature values are found compatible. Interfacial heat transfer coefficient h and heat flux q depending on the experimentally measured temperature values were calculated with finite difference method using explicit technique in C# programming language. In addition to experiments, Flow-3D software simulations were performed using the same parameters. Interfacial heat transfer coefficient and heat flux results obtained from Flow-3D are also presented in the study. Interfacial heat transfer coefficient has decreased as a result of increasing of temperature of mold and pouring. In addition, interfacial heat transfer coefficient values have increased slightly with the increase of injection speed and pressure. It was observed that the values of interfacial heat transfer coefficient and heat flux have also increased when vacuum was applied inside the cavity of the mold. When all injection parameters are considered, it is seen that the interfacial heat transfer coefficient varies between 92-117 kW/m² K.
Źródło:
Acta Physica Polonica A; 2016, 130, 1; 453-458
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
AFM/STM Modification of Thin Sb Films on 6H-SiC(0001)
Autorzy:
Mazur, P.
Zuber, S.
Grodzicki, M.
Ciszewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1195467.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Dz
68.37.Ps
68.37.Ef
68.37.-d
81.10.Bk
81.07.-b
Opis:
Atomic force microscopy and scanning tunneling microscopy have been used for nanometer scale modifications of Sb films deposited on 6H-SiC(0001) surface. The films are grown in situ by vapor deposition under ultrahigh vacuum. The growth follows the Volmer-Weber mode. Ultrathin (up to 3 nm on average) Sb films which consist of no coalesced islands can be modified by moving the island over the substrate surface by the AFM tip. Thicker films, which are firmer due to the coalescence, can be modified by the field and/or current produced by STM tip. Final result of the modifications is adsorbate free 6H-SiC(0001) surface restitution over the modified area.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1131-1133
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sb Layers on p-GaN: UPS, XPS and LEED Study
Autorzy:
Grodzicki, M.
Mazur, P.
Pers, J.
Zuber, S.
Ciszewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1376064.pdf
Data publikacji:
2014-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Dz
68.37.Ps
68.37.Ef
68.37.-d
81.10.Bk
81.07.-b
Opis:
The electronic structure of p-type GaN(0001) surfaces and its modification by antimony adsorption, and properties of Sb/GaN(0001) interface, are presented in this report. The studies were carried out in situ by ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and low-energy electron diffraction. Thin Sb layers were deposited under ultrahigh vacuum conditions onto the substrate at room temperature. Electron affinity of clean p-GaN surface amounted to 3.0 eV. A small amount of Sb on GaN(0001) surface reduced the electron affinity to 1.9 eV. The work function of the Sb layer was equal to 4.4 eV. For the Schottky barrier height of the Sb/GaN interface, the value of 2.50 eV was obtained.
Źródło:
Acta Physica Polonica A; 2014, 126, 5; 1128-1130
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Coupled Spin-Electron Diamond Chain with Different Landé g-Factors of Localized Ising Spins and Mobile Electrons
Autorzy:
Torrico, J.
Pereira, M.
Strečka, J.
Lyra, M.
Powiązania:
https://bibliotekanauki.pl/articles/1032419.pdf
Data publikacji:
2017-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.50.+q
75.10.Pq
75.30.Kz
75.40.Cx
Opis:
A coupled spin-electron diamond chain with localized Ising spins placed on its nodal sites and mobile electrons delocalized over interstitial sites is explored in a magnetic field taking into account the difference between the Landé g-factors of the localized spins and mobile electrons. The ground-state phase diagram is constituted by two classical ferrimagnetic phases, the quantum unsaturated paramagnetic phase and the saturated paramagnetic phase. Both classical ferrimagnetic phases as well as the unsaturated paramagnetic phase are reflected in a low-temperature magnetization curve as intermediate magnetization plateaus. The unsaturated paramagnetic phase is quantum in its character as evidenced by the fermionic concurrence calculated for a pair of the mobile electrons hopping in between the interstitial sites. It is shown that the magnetic field can under certain conditions induce a quantum entanglement above the disentangled ground state.
Źródło:
Acta Physica Polonica A; 2017, 132, 1; 140-142
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
XXX Międzynarodowa Konferencja Naukowa „Socjologia grup dyspozycyjnych. Pomiędzy teorią nauk społecznych a praktyką”, Wrocław, 9–10.05.2019 r.
Report on the 30th International Academic Conference The Sociology of the Uniformed Public Services: between the theory of social sciences and practice (held in Wrocław from 9 to 10 May 2019)
Autorzy:
Mazur, Jadwiga
Powiązania:
https://bibliotekanauki.pl/articles/556611.pdf
Data publikacji:
2019
Wydawca:
Krakowska Akademia im. Andrzeja Frycza Modrzewskiego
Źródło:
Bezpieczeństwo. Teoria i Praktyka; 2019, 4; 223-225
1899-6264
2451-0718
Pojawia się w:
Bezpieczeństwo. Teoria i Praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Substrates Grown from the Vapor for ZnO Homoepitaxy
Autorzy:
Skupiński, P.
Kopalko, K.
Łusakowska, E.
Domukhovski, V.
Jakieła, R.
Mycielski, A.
Grasza, K.
Powiązania:
https://bibliotekanauki.pl/articles/1811990.pdf
Data publikacji:
2008-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.Dz
68.47.Fg
68.55.J-
68.37.Ps
81.10.Bk
81.15.-z
Opis:
The novel method of preparation of epi-ready ZnO substrates is demonstrated. The substrates were made of unique ZnO crystals grown by chemical vapor transport method using hydrogen as the transport agent. The effect of low-level doping (Mn, Co, Cu, and V) on the structural quality of the crystals was investigated. Atomic layer deposition was used to verify usability of the substrates for homoepitaxy. The thermal annealing prior to the atomic layer deposition process and effect of thermal annealing of the epitaxial layers was studied. The X-ray diffraction and atomic force microscopy methods were applied to study the structural quality of the ZnO layers. Detection of the dopants in the substrates by secondary ion mass spectroscopy made possible the measurement of the thickness of the layers. The obtained root mean square roughness for both the substrates and layers ranged between 0.2 nm and 5 nm, and was dependent on the sample crystallographic orientation and sequence of polishing and annealing procedures. The optimal recipe for the epi-ready substrate preparation was formulated.
Źródło:
Acta Physica Polonica A; 2008, 114, 5; 1361-1368
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hard and Soft X-Ray Reflectivity Studies οf $(NiFe//Au//Co//Au)_{10}$ Magnetic Multilayers
Autorzy:
Szymański, B.
Stobiecki, F.
Weis, T.
Engel, D.
Urbaniak, M.
Kuświk, P.
Lengemann, D.
Ehresmann, A.
Powiązania:
https://bibliotekanauki.pl/articles/1810593.pdf
Data publikacji:
2009-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.05.cm
75.60.-d
75.70.-i
Opis:
We report on hard and soft X-ray reflectivity investigations of $(Ni_{80}Fe_{20} (2.2 nm)//Au(2.3 nm)//Co(0.8 nm)//Au(2.3 nm))_{10}$ multilayers. Specular reflectivity curves were measured with Cu $K_{α}$ radiation and circularly polarized synchrotron radiation tuned to Co $L_{3}$ and Ni $L_{3}$ absorption edges. Structural properties of the multilayers were determined from the hard X-ray reflectivity curve. Comparison of reflectivity curves taken at different photon energies shows: (i) small difference in peak positions in dependence of reflectivity versus scattering vector q, (ii) different shapes of satellite Bragg peaks, (iii) different ranges of q for appearance of the Kiessig fringes. Analysis of soft X-ray reflectivity curves taken as a function of magnetic field allows to determine magnetic properties of Co and NiFe layer specifically.
Źródło:
Acta Physica Polonica A; 2009, 115, 1; 366-368
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystal Structure of $(NbSe_4)_3I$ and $(NbSe_4)_{10//3}I$ CDW Compounds at 14 K
Autorzy:
Zubko, M.
Kusz, J.
Prodan, A.
Bennett, J.
Świec, P.
Powiązania:
https://bibliotekanauki.pl/articles/1398362.pdf
Data publikacji:
2016-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.50.Ks
61.05.C-
72.15.Nj
61.72.Mm
61.66.-f
Opis:
Both $(NbSe_4)_3I$ and (NbSe_4)_{10//3}I$ compounds are interesting system possessing quasi one-dimensional linear chain character and exhibiting nonlinear transport properties with a second order phase transition. The compounds are built of $NbSe_4$ antiprisms, stacked along the tetragonal c axis into chains in a screw-like arrangement. Performed X-ray low temperature single crystal diffraction measurements allowed to solve, refine and analyze crystal structures of both compounds at 14 K. While $(NbSe_4)_{10//3}I$ compound undergoes structural phase transition to monoclinic phase, $(NbSe_4)_3 I$ remains in tetragonal symmetry. Iodine atoms are responsible for the differences in $(NbSe_4)_{10//3}I$ and $(NbSe_4)_3 I$ structures causing different spacing in the infinite $NbSe_4$ chains.
Źródło:
Acta Physica Polonica A; 2016, 130, 4; 869-872
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single Pulse Laser Ablation of AISI 316L Stainless Steel Surface Using Nd:YAG Laser Irradiation
Autorzy:
Demir, P.
Kacar, E.
Akman, E.
Demir, A.
Powiązania:
https://bibliotekanauki.pl/articles/1195232.pdf
Data publikacji:
2014-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.62.-b
44.05.+e
44.10.+i
61.82.-d
61.82.Bg
79.20.Eb
Opis:
The interaction of single-pulse Nd:YAG laser, operating at 1064 nm wavelength and 6 ns pulse duration, with AISI 316L stainless steel target surface was investigated experimentally and theoretically. Surface modification of stainless steel using laser irradiation was studied by observing the effects of varying incident laser pulse intensities on surface morphology. Surface structure of laser treated stainless steel was determined by optical microscopy and profilometry analyses. Numerical calculation by heat transfer equation was performed for single laser pulse irradiation. The results, obtained by theoretical and experimental processes, of the interaction between single-pulse Nd:YAG laser irradiation and AISI 316L stainless steel target surface are reported.
Źródło:
Acta Physica Polonica A; 2014, 125, 2; 439-441
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nanocrystallisation of Soft Magnetic Fe-Co-Zr-Cu-B Alloys
Autorzy:
Wlazłowska, A.
Ferenc, J.
Latuch, J.
Kulik, T.
Powiązania:
https://bibliotekanauki.pl/articles/2035520.pdf
Data publikacji:
2002-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
75.50.Bb
75.50.Kj
75.60.Ej
81.05.Kf
81.10.Jt
81.70.Ex
81.70.Pg
Opis:
In the present study, Fe$\text{}_{41}$Co$\text{}_{41}$B$\text{}_{10}$Zr$\text{}_{7}$Cu$\text{}_{1}$ alloy has been investigated in order to evaluate its thermal stability and structure after heat treatment, as well as the impact of heat treatment on magnetic properties. X-ray diffractometry, differential scanning calorimetry, chemical composition microanalysis, transmission electron microscopy, and magnetic hysteresis loop measurement techniques were employed. The crystallisation temperature of the as-quenched alloy is 490ºC (continuous heating at 5ºC/min). The melt-spun ribbon having 27μm in thickness was annealed for 1 hour at temperatures from 400 to 700ºC. The alloy after treatment at about 550ºC underwent primary crystallisation, with the average size of crystals under 20 nm. This specimen shows the coercive field of 38 A/m, as compared to about 160 A/m reported for a similar alloy (Fe$\text{}_{44}$Co$\text{}_{44}$B$\text{}_{4}$Zr$\text{}_{7}$Cu$\text{}_{1}$) with a similar structure, annealed at 600ºC.
Źródło:
Acta Physica Polonica A; 2002, 102, 2; 323-328
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FTIR Study of Nanostructure Perovskite $BaTiO_3$ Doped with Both $Fe^{3+}$ and $Ni^{2+}$ Ions Prepared by Sol-Gel Technique
Autorzy:
Abdel Aal, A.
Hammad, T.
Zawrah, M.
Battisha, I.
Abou Hammad, A.
Powiązania:
https://bibliotekanauki.pl/articles/1377829.pdf
Data publikacji:
2014-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.20.Fw
81.07.Bc
64.70.kg
61.05.C-
78.30.Ly
81.10.Aj
Opis:
Pure barium titanate $BaTiO_3 (BT)$ and BT doped with two different transition elements $Fe^{3+}$ and $Ni^{2+}$ at 5 mol.% (BT5Fe and BT5Ni, respectively) as constant concentration in powder form have been prepared by sol-gel method using barium acetate, titanium(IV) n-butoxide, iron and nickel nitrates as precursor materials. The microstructure of BT and the influence of Fe and Ni dopants on it were investigated by X-ray diffraction and Fourier transform infrared spectroscopy. X-ray diffraction shows that tetragonal phase is dominant for pure BT sintered for 4 h at 800°C. Scanning electron microscopy and transmission electron microscopy were used to study surface morphology and particle size distribution for BT5Fe and BT5Ni, respectively. The presence of hydroxyl defects were verified by Fourier transform infrared spectroscopy for $(BaTi_{1-x}Fe_{x}O_{3-x/2}) (BT_xFe)$, where x=0.005, 0.01, 0.05, and 0.07 and $(BaTi_{1-x}Ni_{x}O_{3-x/2}) (BT_xNi)$, where x=0.005, 0.01, 0.03, 0.05, and 0.07.
Źródło:
Acta Physica Polonica A; 2014, 126, 6; 1318-1321
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-ray Topographic Investigations of Domain Structure in Czochralski Grown $Pr_{x}La_{1-x}AlO_{3}$ Crystals
Autorzy:
Wieteska, K.
Wierzchowski, W.
Malinowska, A.
Turczyński, S.
Lefeld-Sosnowska, M.
Pawlak, D.
Łukasiewicz, T.
Graeff, W.
Powiązania:
https://bibliotekanauki.pl/articles/1538809.pdf
Data publikacji:
2010-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.05.-t
81.10.Dn
61.72.Ff
Opis:
In the present paper X-ray diffraction topographic techniques were applied to a number of samples cut from Czochralski grown $Pr_{x}La_{1-x}AlO_{3}$ crystals with different ratio of praseodymium and lanthanum. Conventional and synchrotron X-ray topographic investigations revealed differently developed domain structures dependent on the composition of mixed praseodymium lanthanum aluminium perovskites. Some large mosaic blocks were observed together with the domains. In the best crystals, X-ray topographs revealed striation fringes and individual dislocations inside large domains. Synchrotron topographs allowed us to indicate that the domains correspond to three different crystallographic planes, and to evaluate the lattice misorientation between domains in the range of 20-50 arc min.
Źródło:
Acta Physica Polonica A; 2010, 117, 2; 268-271
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combined Atom Probe Tomography and TEM Investigations of CoCrFeNi, CoCrFeNi-Pd_x (x=0.5, 1.0, 1.5) and CoCrFeNi-Sn
Autorzy:
Cornide, J.
Calvo-Dahlborg, M.
Chambreland, S.
Asensio Dominguez, L.
Leong, Z.
Dahlborg, U.
Cunliffe, A.
Goodall, R.
Todd, I.
Powiązania:
https://bibliotekanauki.pl/articles/1402078.pdf
Data publikacji:
2015-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.Dk
Opis:
The structure of a family of high entropy alloys based on the composition CoCrFeNi, to which Pd and Sn have been added, is presented. The results stem from combined investigations by atom probe tomography as well as by scanning and transmission electron microscopy on samples produced by arc melting. Although CoCrFeNi is of fcc structure, the sample is not homogeneous on atomic scale. The addition of Pd as a fifth element retains the fcc lattice with the indication of the coexistence of at least two additional phases. The addition of Sn changes the general structure considerably.
Źródło:
Acta Physica Polonica A; 2015, 128, 4; 557-560
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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