Wyniki wyszukiwania - BazTech

1

Generation of dedicated finite element meshes for multiscale applications with Delaunay triangulation and adaptive finite element - cellular automata algorithms

Madej L., Krużel P., Cybułka P., Perzyński K., Banaś B.

Computer Methods in Materials Science

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2012

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Vol. 12, No. 2

85-96

EN

The main aim of the work is development and comparison of algorithms for mesh creation that can be further used to investigate material behavior under loading conditions, on the basis of digital material representation. Particular attention is put on development of conforming meshes for two-phase materials. Two approaches are investigated within the present work. The first is based on mesh refinement along particular microstructure features. The second incorporates cellular automata phase transformation model into the FE element adaptation technique. Description of the two approaches and example of application of the obtained meshes to analysis of the multiscale material behavior under plastic deformation condition are presented.

PL

Głównym celem pracy jest opracowanie i porównanie algorytmów generowania siatek, elementów skończonych, które można wykorzystać do badania zachowania materiału w warunkach odkształcenia z wykorzystanie idei cyfrowej reprezentacji materiału. W pracy szczególna uwaga została położona na odwzorowanie stopniem zagęszczenia elementów morfologii materiałów dwufazowych. W tym celu wykorzystano dwa różne algorytmy. Pierwszy oparty jest na utworzeniu siatki poprzez triangulacje Delaunay przy jednoczesnym jej zagęszczeniu wzdłuż poszczególnych elementów mikrostruktury. Drugi obejmuje wykorzystanie modelu przemiany fazowej opracowanego na bazie metody automatów komórkowych i sprzęgnięcie go z algorytmami adaptacji siatki podczas rozwiązania MES zagadnienia liniowej sprężystości. Opis w/w algorytmów oraz przykład zastosowania uzyskanych siatek do wieloskalowej analizy zachowania się mikrostruktury w warunkach odkształcenia plastycznego jest zamieszczony w ramach niniejszej pracy.

2

The Mixed-Valence Rhenium(IV, V) Complexes

Banaś B., Nahorska M., Tomkiewicz A., Kłak J., Cyfert M., Mroziński J.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 10

1663-1676

EN

Reaction of K4[Re2OCl10]with oxidizing agents in hydrochloric acid produced binuclear compounds: Cs3[Re2OCl10] 1, (Ph4As)3[Re2OCl10] 2, (ChinH)3[Re2OCl10] 3. These complexes had been characterized by kinetic and magnetic investigations. The low-temperature magnetic susceptibility measurements have revealed, that Cs3[Re2OCl10] complex is antiferromagnets, with Néel temperature at 10 K. The temperature dependence of the magnetic moment for 2 and 3 complexes indicates the existence of a magnetically isolated exchange-coupled dimer. In the electronic spectra, the intensive band at 20150 cm–1 is associatedwith the presence of the two different oxidation states. In agreementwith the evidence from the oxidation of oxochlororhenate ion and the disproportionation in solution, it is proposed that the compound should be considered as a Re(IV)–Re(V) mixed-valence system.

3

Poliwęglany (PC) - rozwój technologii

Banaś B., Tkacz B., Krueger A.

Chemik

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2004

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Vol. 57, nr 5

158-161

PL

Omówiono metody otrzymywania poliwęglanów (PC): metodę fosgenową oraz metody bez użycia fosgenu - transestryfikację węglanu difenylu (DPC) i dimetylu (DMC) bisfenolem A (BPA) oraz utleniającego karbonylowania BPA. Oceniono możliwości zastąpienia stosowanej przez większość producentów PC technologii fosgenowej metodami tańszymi i bardziej przyjaznymi dla środowiska. Z alternatywnych metod syntezy stopniowo wprowadzana jest technologia stopowa - transestryfikacji węglanu difenylu bisfenolem A. Dużą szansę na zastosowanie w skali przemysłowej ma metoda transestryfikacji węglanu dimetylu bisfenolem A, natomiast otrzymywanie poliwęglanów w reakcji utleniającego karbonylowania BPA wymaga dalszych prac badawczych.

EN

Methods for synthesis of polycarbonate (PC) were presented: phosgene technology and methods without using phosgene - transesterification of diphenyl carbonate (DPC) and dimethyl carbonate (DMC) with bisphenol A (BPA) and oxidative carbonylation of BPA. Possibility of replacement of phosgene technology by cheaper and more environmentally friendly methods was discussed. An alternative melt method - transesterification of diphenyl carbonate with bisphenol A is gradually introduced. The transesterification of dimethyl carbonate can be used in the industrial scale soon. The oxidative carbonylation in the present time required intensive research work.

4

Kinetic, Spectroscopic and Magnetic Properties of 1,4,8,11-Tetraazacyclotetradecanenickel Bi- and Trivalent Complexes

Banaś B., Nahorska M., Korybut-Daszkiewicz B, Mroziński J.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 1

21-29

EN

Nickel(II) and nickel(III) complexes of formula [NiIILCl2] and [NiIIILCl2]+ containing tetraaza macrocyclic ligands with nitrogen donor atoms, where L = [14]aneN4 (L1), 2-Me[14]aneN4 (L2), 5,12-Me2[14]aneN4(L3), 5,7,7,12,14,14-Me6[14]aneN4 (L4), form stable crystals with a pseudo-octahedral geometry of central atom. This work concerns the methyl analogues of Ni(II) and Ni(III) complexes. Magnetic and spectroscopic measurements gave values of spectroscopic parameter g and paramagnetic temperature dependence characteristic for this type of compounds. Their properties were investigated using EPR, reflectance spectroscopy and IR techniques. The Faraday method was used for the investigation of magnetic susceptibility between 4.2-300 K.

5

Influence of anions on the reversible Ru3O2(NH3)147+ - Fe(II) electron transfer system

Banaś B., Nahorska M., Mroziński J.

Bulletin of the Polish Academy of Sciences. Chemistry

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2001

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Vol. 49, No. 3

203-211

EN

The influence of perchlorate, chloride and sulphate ions on the reversible electron transfer redox system formula was examined in the acidic solution by the stopped-flow spectrophotometry. The positive salt effect, typical of reactions between similarly charged ions, and an unusually strong accelerating effect of chloride and sulphate ions on the reactions rates were observed. The latter could be explained in terms of complex formation between the iron ions and the anions investigated with the resultant complexes reacting faster than respective iron-aqua complexes.

6

Kinetics and Mechanism of Outer-Sphere Reduction of the Oxo-Bridged Trinuclear [(NH3)5RuORu(NH3)4ORu(NH3)5]7+ with Thiosulphate in Acidic Medium

Banaś B.

Polish Journal of Chemistry

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2000

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Vol. 74, nr 10

1411-1419

EN

The kinetics of the reduction of -oxo bridged ruthenium(III,IV) complex, [(NH3)5RuORu(NH3)4ORu(NH3)5]7+, with thiosulphate ion in acidic medium has been investigated by conventional and stopped-flow spectrophotometry in the broad range of reagents concentration, pH and temperature. The reaction follows first order kinetics with respect to the ruthenium complex concentration. The reaction order with respect to [S O ] 2 3 2- depends on the reductor concentration and changes from 1 to 2 with[S O ] 2 3 2- increase. At a sufficient excess of thiosulphate concentration over the ruthenium complex concentration, the reaction displays saturation kinetics, what can be interpreted by ion-pairs formation between the highly and oppositively charged reactants, followed by one-electron transfer from S O 2 3 2- to the ruthenium centers. The presence of the precursor outer-sphere complexes has been detected kinetically and the rate constants for intramolecular electron transfer within the ion-pairs have been calculated.