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1

A Two-Stage Monte Carlo Approach for Optimization of Bimetallic Nanostructures

Mikhov Rossen, Myasnichenko Vladimir, Kirilov Leoneed, Sdobnyakov Nickolay, Matrenin Pavel, Sokolov Denis, Fidanova Stefka

Annals of Computer Science and Information Systems

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2020

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Vol. 21

285--288

EN

In this paper we propose a two-stage lattice Monte Carlo approach for optimization of bimetallic nanoalloys: simulated annealing on a larger lattice, followed by simulated diffusion. Both algorithms are fairly similar in structure, but their combination was found to give significantly better solutions than simulated annealing alone. We also discuss how to tune the parameters of the algorithms so that they work together optimally.

2

Review on hierarchically microstructured monolithic reactors for high yield continuous production of fine chemicals

Mrowiec-Białoń J., Ciemięga A., Maresz K., Szymańska K., Pudło W., Jarzębski A. B.

Chemical and Process Engineering

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2018

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Vol. 39, nr 4

367–-375

EN

Preparation and properties of hierarchically structured porous silica monoliths have been discussed from the viewpoint of their application as continuous microreactors for liquid-phase synthesis of fine chemical in multi kilogram scales. The results of recent topical papers published by two research teams of Institute of Chemical Engineering Polish Academy of Sciences (ICE) and Department of Chemical Engineering and Process Design, Chemical Faculty, Silesian University of Technology (SUT) have been analyzed to specify the governing traits of microreactors. It was concluded that even enhancement factor of 100 in activity, seen in enzyme catalyzed reactions, can be explained by a proportional reduction of its physical constraints, i.e. huge enhancement of external mass transfer and micromixing. It is induced by very chaotic flows of liquid in tens of thousands of waving connected channels of ca. 25–50 mm in diameter, present in the skeleton. The scale of enhancement in the caseof less active catalysts was smaller, but still large enough to consider the most practical applications.

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The examples of the research of the nanostructured engineering materials and the concept of the new generation of highly innovative advanced pioneering nanostructured composite materials

Dobrzański L. A.

Archives of Materials Science and Engineering

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2016

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Vol. 82, nr 1

5--37

EN

Purpose: The first part of the paper presents the outcomes of a dozen of own researches in the field of nanotechnology, carried out over the last several years. The second part of the paper presents the new Author’s ideas on the predicted development of the new generation of highly innovative advanced pioneering nanostructured composite materials through the interaction of the extended nanoengineering components. Design/methodology/approach: Each of the selected topics was briefly described, with special emphasis laid on the issue of structural and phase transitions, which are generally taking place in the newly created original engineering materials and their related original technologies. Each of the descriptions was arbitrarily illustrated with a metallographic photographs made with electron microscopes, most often a transmission microscope, mainly a high-resolution or scanning microscope. The scientific objective of the planned research is to recognise and explain the relevant structural mechanisms, in each case, of synthesis and/or production and formulation of the structure and properties of a new generation of pioneering nanostructured composite materials through the interaction of the extended nanoengineering components and to characterise and model their structure and properties depending on the compositional, phase and chemical composition and the applied synthesis and/or production and/or processing processes. Findings: The research covered by the paper is pursued in the field of nanotechnology as the designing and manufacture of structures with new properties resulting from a nanosize. The planned research is of priority cognitive importance as theoretical considerations, indicate a great need to intensify scientific research to develop new groups of materials with completely unexpected foreseeable effects, resulting from the use of the extended nanoengineering components for manufacturing super advanced nanocomposite materials. Phenomena and processes at a nanoscale can be better recognised by producing a new generation of functional nanostructural materials. Practical implications: The measurable scientific effects concern the cognitive nature of the planned research and are associated with the determination of: the effect of compositional, phase and chemical composition, of the newly developed technologies of fabrication and surface micro-treatment inside pores, of internal precipitated phases or nanoinclusions or surface treatment of micropores in order to apply nanomaterials enabling the improvement of specific properties on the structure and properties of the newly created nanocomposite materials with the extended nanoengineering components ensuring the improvement of specific properties and the modelling of the structure and properties of the researched newly created nanocomposite materials using artificial intelligence methods. The research will comprise the fabrication of materials with new unforeseeable properties fulfilling multiple functions. Originality/value: Phenomena and processes at a nanoscale can be better recognised by producing a new generation of functional nanostructural materials (physicochemical basis of nanomaterials and nanostructures synthesis, with controlled architecture and properties, engineering of atomic and molecular bonds, models and theories explaining the properties of nanomaterials, surface phenomena, self-assembly phenomena in nanomaterials and nanostructures synthesis, magnetic phenomena in semiconducting and metallic nanostructures).

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Mechanizmy odkształcenia materiałów nanostrukturalnych

Krella A.

Inżynieria Materiałowa

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2011

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Vol. 32, nr 5

844-850

PL

Nanomateriały stanowią obecnie ważną grupę materiałów znajdujących zastosowanie prawie we wszystkich dziedzinach przemysłu. W badaniach nanomateriałów stwierdzono, że zależność Halla-Petcha nie jest spełniona dla całego zakresu 1÷100 nm. W przypadku nanomateriałów o wielkości ziaren poniżej pewnej wartości krytycznej zaobserwowano efekt zmniejszenia twardości wraz ze zmniejszeniem się wielkości ziarna. Z tego względu wiele badań poświęcono poznaniu ich budowy i mechanizmów odkształcania. Badania prowadzone za pomocą transmisyjnego mikroskopu elektronowego wykazały, że nanokrystaliczne materiały są zbudowane z małych krystalitów o zróżnicowanej orientacji krystalograficznej, oddzielonych od siebie szerokokątowymi granicami ziaren, w których są obserwowane pustki (rys. 1). Pustki te były wyraźnie większe w miejscach styku trzech ziaren, tzw. triple junction. Ze względu na istotny wzrost udziału granic ziaren (rys. 2) wraz ze zmniejszaniem się wielkości ziaren oraz mniejszą gęstość atomową w porównaniu z ziarnami, najczęstszym modelem struktury nanomateriałów jest model dwufazowy składający się fazy wewnętrznej ziarna i fazy granicy ziarna (rys. 3). Jednym z wyjaśnień zjawiska zmniejszenia twardości nanomateriałów jest zwiększenie w budowie nanomateriału udziału granic ziaren (rys. 2), których gęstość jest znacznie mniejsza niż gęstość ziaren oraz odmienne mechanizmy odkształcania. Badania doświadczalne, symulacje dynamiki molekularnej oraz modele odkształcenia nanokrystalicznych materiałów wykazały, że odkształcanie nanomateriałów przebiega na skutek poślizgu wzdłuż granic ziaren, dyfuzji po granicy ziaren, dyfuzji w ziarnach, rotacji ziaren, powstania pasm ścinania, generowania dyslokacji przez granice ziaren, mechanicznego bliźniakowania, a także w wyniku ruchu dyslokacji wewnątrz ziaren, z tym, że ten ostatni mechanizm zanika wraz ze zmniejszaniem się wielkości krystalitów.

EN

Nanomaterials are nowadays very important group of materials which are used in most branches of industry. The investigations of the strength of nanomaterials showed that the Hall-Petch law is not valid in the same form for the whole range from 1 to 100 nm. When the grain size falls below the critical size the effect of decrease of strength (softening) is observed. Therefore, many studies were performed to learn their structure and deformation mechanisms. Investigation performed by means of high resolution transmission electron microscopy (HRTEM) showed that nanocrystalline materials consist of small crystallites of different crystallographic orientations separated by the grain boundaries of large angle type, which consists of pores (Fig. 1). These pores have bigger size at triple junctions. Due to low atomic density of grain boundary and an increase of grain boundary fraction with decrease of grain size (Fig. 2), the most frequent model of nanomaterials structure is two-phase model which consists of the grain interior phase and the grain boundary phase (Fig. 3). One of the explanation of the softening effect of the nanostructured materials is the increase of fraction of grain boundary (Fig. 2), whose density and strength is lower than those of grains. Another explanation says that the softening effect is due to deformation mechanisms that are different from those present in their coarse-grained counterparts. Experimental investigations, molecular dynamic simulation and many models showed that deformation of nanocrystalline materials develops via grain boundary sliding, grain boundary diffusion, shear-band formation, mechanical twinning, dislocation climb, rotation at triple junctions, grain-boundary dislocation creation and annihilation and also via dislocation motion inside grain.

5

Nanostrukturalne materiały termoelektryczne

Wojciechowski K.

Elektronika : konstrukcje, technologie, zastosowania

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2009

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Vol. 50, nr 9

68-71

PL

W artykule dokonano zwięzłego przeglądu najważniejszych koncepcji dotyczących nowej grupy nanostrukturalnych materiałów termoelektrycznych. Dzięki kwantowym efektom rozmiarowym możliwe jest zwiększenie ponad dwukrotnie efektywności konwersji energii w stosunku do dotąd stosowanych klasycznych materiałów litych. Nowe materiały nanostrukturalne mogą znaleźć szerokie zastosowanie w m.in. w elektronice do konstrukcji miniaturowych elementów chłodzących oraz mikrogeneratorów termoelektrycznych.

EN

A brief overview of key concepts of a new group of nanostructured thermoelectric materials is given. Owing to quantum size effects it is possible to increase the efficiency of energy conversion, in relation to previously used c1assical bulk materials, more than twice. New nanostructured materials may find wide application, especially in electronics, in manutacture of miniature thermoelectric coolers and microgenerators.

6

Nanoproszki i warstwy z materiałów termoelektrycznych-otrzymywanie i charakterystyka

Wojciechowski K., Gajerski R., Grzonka J., Mania R., Mars K., Morgiel J., Zybała R.

Elektronika : konstrukcje, technologie, zastosowania

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2009

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Vol. 50, nr 9

65-67

PL

Przedstawiono wybrane wyniki prac dotyczące dwóch metod otrzymywania nanostrukturalnych materiałów termoelektrycznych z grupy skutterudytów oraz warstw tellurku antymonu. Nanoproszki CoSb₃ otrzymywane były metodą rozkładu termicznego aerozoli a następnie redukcji w atmosferze wodoru. Warstwy tellurku antymonu wytwarzano techniką impulsowego rozpylania magnetronowego. Otrzymane materiały poddane były szczegółowym badaniom mikrostruktury i składu fazowego oraz właściwości termoelektrycznych.

EN

The paper presents selected results of two methods of preparation of nanostructured thermoelectric materials from group of skutterudites and antimony telluride layers. Nanopowders ot CoSb₃ were obtained using thermal decomposition and reduction of aerosol s in the atmosphere of hydrogen. Antimony telluride layers were produced by pulse magnetron sputtering. The materials were subject of detailed examination of the microstructure, phase composition and thermoelectric properties.

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Przegląd technik formowania nanowłókien. Część I. Techniki laboratoryjne

Bendkowska W.

Przegląd Włókienniczy - Włókno, Odzież, Skóra

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2007

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nr 10

31-35

EN

In recent years, one dimensional (1D) nanostructured materials such as nanorods, nanowires, nanotubes, nanowhiskers or nanofibers have been intensively studied owing to their potential technological applications in many areas including mechanics, electronics, optics, photonics, optoelectronics, catalysis, sensing, filtration, biotechnology and biomedicine. A large number of synthesis and fabrication methods have been developed for generating 1D nanostructures from various materials. This paper gives an overview of the techniques currently used in laboratory research such as drawing, template syntesis, phase separation and self assembly.

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Application of nanostructural materials in manufacturing of soft magnetic composite materials Fe73.5Cu1Nb3Si13.5B9 - PEHD type

Ziębowicz B., Dobrzański L. A.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 2

91-94

EN

Purpose: The purpose of the paper is to show the possibility of application in different branches the techniques of nanostructural soft magnetic composite materials: Fe73.5Cu1Nb3Si13.5B9 alloy powder bounded by polyethylene and the worked out technique of their obtaining. Design/methodology/approach: The main base of the paper is to show the properties and possibilities of application of modern nanostructural soft magnetic composite materials as a result of finding new nanotechnologies that result the practical application of nanomaterials obtained by these techniques. Findings: Modern nanostructural soft magnetic composite materials have optimum technology of production with properties that allow for miniaturizing, simplification and lowering the costs of devices. Practical implications: Showing the possibilities of new technological solutions leading to manufacture materials than can replace the traditional ones. Originality/value: The paper shows samples of nanostructural magnetic composite materials and shows the material and technological solution which make possible obtaining these materials.