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1

Properties of Confined Polymer Melts

100%

Sikorski A.

Acta Physica Polonica A

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2005

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vol. 107

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issue 3

443-450

EN

Properties of simple models of confined linear polymer chains were studied by means of the Monte Carlo method. Model chains were built of united atoms (statistical segments) and embedded to a simple cubic lattice. Then polymers were put into a slit formed by two parallel impenetrable surfaces. Chain lengths were varied up to 800 segments and the density of the polymer melt was changed up to 0.5. A Metropolis-like sampling Monte Carlo algorithm was used to determine the static properties of this model. The influence of the size of the confinement, the polymer melt concentration and the chain length on the chain's size and the structure was studied. The universal behavior of all confined polymer linear chains under consideration was found and discussed.

2

Structure of Dense Polymer Systems Confined to a Slit

100%

Sikorski A.

Acta Physica Polonica A

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2006

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vol. 109

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issue 2

133-141

EN

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.

3

The Shape of Confined Polymer Chains

100%

Sikorski A.

Acta Physica Polonica A

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2003

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vol. 103

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issue 4

339-347

EN

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^{1.18} to N^{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.

4

Predictive current control of three-phase matrix converter with GaN HEMT bidirectional switches

72%

Nowaszewski K., Sikorski A., Nowaszewski K., Sikorski A.

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2020

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issue 5

5

Monte Carlo Study of Chain Entanglements in Polymer Melt

64%

Sikorski A., Romiszowski P.

Acta Physica Polonica A

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2001

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vol. 100

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issue 4

477-484

EN

The new multibond algorithm for the Monte Carlo simulations of polymers developed for an isolated chain was extended for the case of dense polymer melts. Polymer chains were confined to a simple cubic lattice with excluded volume and no attractive interactions (good solvent conditions). The simulations were carried out by the means of the classical Metropolis scheme. The algorithm was verified by the analysis of static and dynamic properties of polymer melts. The dependence of the longest relaxation time and the self-diffusion coefficient on the chain length and the polymer concentration was discussed and the proper scaling laws were formulated. The number of entanglements, their distribution, and lifetimes were determined for different chain lengths and melt concentrations using the new algorithm.

6

New Multi-Bond Algorithm for Monte Carlo Simulation of Lattice Chains

64%

Romiszowski P., Sikorski A.

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vol. 96

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issue 6

691-697

EN

The new algorithm for the Monte Carlo simulations of polymer lattice chains was developed. The model chains were constructed on a simple cubic lattice. The simulations were carried out on chains with and without excluded volume effect using the Metropolis scheme. The basic concept of the new algorithm is the multi-bond modification of the chain conformation instead of applying the classical set of elementary micromodifications. The correctness of the algorithm was verified by studying both static and dynamic properties of the chains. The new algorithm was found to be 3 to 8 times faster than the classical one.

7

Cooperation of induction squirrel-cage generator with grid connected AC/DC/AC converter

64%

Sikorski A., Kuźma A.

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2009

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vol. 57

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issue 4

8

Efficiency improvement due to direct torque and flux three levels three areas control method applied to small hydroelectric power plant

64%

Kulikowski K., Sikorski A.

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2011

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issue 4

9

AC/DC/AC converter in a small hydroelectric power plant

64%

Sikorski A., Korzeniewski M.

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2011

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issue 4

10

Properties of active rectifier with LCL filter in the selection process of the weighting factors in finite control set-MPC

51%

Falkowski P., Sikorski A., Kulikowski K., Korzeniewski M.

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2020

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issue 1

11

Collapse of Semiflexible Polymers in Two Dimensions. Monte Carlo Simulations

51%

Koliński A., Vieth M., Sikorski A.

Acta Physica Polonica A

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1991

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vol. 79

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issue 5

601-612

EN

We present Monte Carlo simulations of a two-dimensional square lattice semi-flexible polymer model. Short-range repulsive potential (excluded volume) and long-range attractive (segment-segment) potential are included. Particular attention was paid to a phase transition of a model polymer chain from a random coil state to a dense globule. The transition temperature increases with the chain length and decreases with the stiffness of the model chain. The cooperativity of the transition increases with the polymer stiffness.

12

Modern Direct Torque and Flux Control methods of an induction machine supplied by three-level inverter

51%

Sikorski A., Kulikowski K., Korzeniewski M.

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2013

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issue 4

13

Adaptive, predictive and neural approaches in drive automation and control of power converters

46%

Kabziński J., Orłowska-Kowalska T., Sikorski A., Bartoszewicz A., Kabziński J., Orłowska-Kowalska T., Sikorski A., Bartoszewicz A.

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2020

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issue 5

14

Prevalence and distribution of Dirofilaria repens Railliet et Henry, 1911 in dogs in Poland

39%

Osińska B., Demiaszkiewicz A. W., Polańczyk G., Pyziel A. M., Kuligowska I., Lachowicz J., Sikorski A.

Polish Journal of Veterinary Sciences

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2014

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issue 3

Refine search results

Properties of Confined Polymer Melts

Structure of Dense Polymer Systems Confined to a Slit

The Shape of Confined Polymer Chains

Predictive current control of three-phase matrix converter with GaN HEMT bidirectional switches

Monte Carlo Study of Chain Entanglements in Polymer Melt

New Multi-Bond Algorithm for Monte Carlo Simulation of Lattice Chains

Cooperation of induction squirrel-cage generator with grid connected AC/DC/AC converter

Efficiency improvement due to direct torque and flux three levels three areas control method applied to small hydroelectric power plant

AC/DC/AC converter in a small hydroelectric power plant

Properties of active rectifier with LCL filter in the selection process of the weighting factors in finite control set-MPC

Collapse of Semiflexible Polymers in Two Dimensions. Monte Carlo Simulations

Modern Direct Torque and Flux Control methods of an induction machine supplied by three-level inverter

Adaptive, predictive and neural approaches in drive automation and control of power converters

Prevalence and distribution of Dirofilaria repens Railliet et Henry, 1911 in dogs in Poland