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1

Influence of rod diameter on acoustic band gaps in 2D phononic crystal

Gruszka K., Nabiałek M., Szota M.

Archives of Materials Science and Engineering

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2014

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Vol. 68, nr 1

24--30

EN

Purpose: The purpose of this paper is to investigate influence of changing the fill factor (or rod diameter) on acoustic properties of phononic crystal made of mercury rods inside of water matrix. Change in construction of primary cell without changing the shape of rod may cause shifts in bands leading to widening of forbidden band gaps, which is the basis of modern composite material designing process. Design/methodology/approach: Band structure is determined by using the finite element study known as finite difference frequency domain simulation method. This is achieved by virtual construction and simulation of primary cell of phononic crystal. Phononic crystals are special devices which by periodic arrangement of properties related to the sound can affect the transmission of acoustic waves thru their body. Findings: The fill factor/rod diameter has a significant influence on the acoustic band structure of studied phononic crystal which can be divided in two mainly effects: fission and compression of band structure. Research limitations/implications: In order to better understand basic properties of phononic crystals and to get full control over the band gaps a series of similar calculations should be done for broader range of frequencies covering both infrasound and ultrasound wavelength regions. Also structures of other cut shape of rod and different primary cell structure resulting in diverse phononic crystal structure should be investigated in the future. Practical implications: Phononic crystals are important devices in variety of applications ranging from noise control through acoustic computing, health applications and entertainment up to military applications. Therefore full knowledge about specific working conditions and elementary properties is necessary for complete control in targeted applications. Controlling the fill factor is one of the simplest methods to achieve specific band gap positions and widths. Originality/value: The novelty is in use of different phase materials with similar acoustic characteristics affecting the hole sonic properties of device manifested by their calculated band structure. The target group are scientists interested in practical applications of various acoustic materials.

2

Diody termiczne - potencjalne możliwości wykorzystania diod termicznych w technice

Fieducik J., Godlewski J.

Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

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2012

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z. 59, nr 2/II/I

195-201

PL

W artykule przedstawiono zagadnienia przewodnictwa i przenikania ciepła w różnych strukturach. Przeanalizowano działanie różnych rodzajów makro, mikro i nano diod termicznych. Wskazano możliwości transportu ciepła przy pomocy diod w ściśle określonym kierunku, oraz możliwości wykorzystania tych rozwiązań w budownictwie.

EN

The paper presents issues relating to conduction and heat transfer in different structures. The operation of different types of macro, micro and nano thermal diodes were analyzed. The potential of heat transport through diodes in a specific direction, and the possibility of using these solutions in construction were described.

3

Określenie właściwości smarnych oleju napędowego z hydrokrakingu w funkcji zawartości estrów CHO

Kajdas Cz., Korycki J., Frydrych J.

Tribologia

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2007

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nr 2

219-227

PL

W pracy przedstawiono wybrane wyniki badań właściwości smarnych dodatków estrowych CHO (węgiel, wodór i tlen) w oleju napędowym z hydrokrakingu o zawartości siarki poniżej 5 ppm.

EN

The paper presents findings concerning lubricity proprieties of four CHO (carbon, hydrogen and oxygen) ester additives: cholesteryl acetate, methyl butyrate, methyl decanoate and cholesteryl palmitate, added to a hydrocracked diesel fuel base oil (LON) - containing less than 5 ppm sulphur - in the concentration range from 100 to 10000 ppm. One proposed a new mechanism of the ester hydrolysis and the formation of the film which is the result of the action of excited states produced during the friction process. The friction process releases the free energy to structures and molecules of the core, the surface layer, Langmuir - Blodget layer and the lubricant, and in the form of chemical energy at fragmentation of the additive molecules, and additionally also by generating electrons plus quanta of the energy such as : photons, phonons, excitons, solitons etc. [L. 2]. The formation of anion-radicals and tribochemical processes stimulated are processes releasing of the energy, small particles and fragments of molecules.

4

Śladem energii od deformacji do stanu wzbudzenia chemicznego

Korycki J.

Tribologia

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2005

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nr 2

153-172

PL

W pracy naszkicowano pogląd na przebieg procesów przekazywania energii w procesach tarcia i zużycia. Jako źródło energii wskazano procesy tarcia, powodujące procesy deformacji: rdzenia metalu, warstwy wierzchniej, warstwy Langmiura--Blodgeta i cieczy smarującej. Procesy te uwalniają energię swobodną do struktur i molekuł rdzenia, warstwy wierzchniej, warstwy Langmiura-Blodgeta i cieczy smarującej oraz w postaci energii chemicznej przy fragmentacji struktur czy molekuł, a też generując cząstki jako elektrony, kwanty energii jak: fotony, fonony, ekscytrony, soliony...

EN

The opinion on the course of processes of the transfer of the energy in friction and wear processes had been presented in this paper. As the source of energy was pointed friction process, causing deformation process: of the metal core, surface layer, Langmuir - Blodget layers and the bulk lubricant. These processes release the free energy to structures and molecules of the core, the surface layer, Langmuir - Blodget layer and the lubricant, and in the form of chemical energy at fragmentation of structures or molecules, and additionally also by generating electrons plus quanta of the energy such as: photons, phonons, excitons, solitons....

5

Energia deformacji a reakcje tribochemiczne

Kajdas C., Korycki J.

Tribologia

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2005

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nr 5

41-54

PL

By zrozumieć procesy tribochemiczne zachodzące podczas tarcia granicznego zaproponowano zasadę uogólniającą dotychczasowy proces aniono-rodnikowy [L. 1], o dostarczenie energii i ładunku. Jako źródło energii wskazano procesy tarcia, powodujące procesy deformacji: rdzenia metalu, warstwy wierzchniej, warstwy Langmuira-Blodgeta i cieczy smarującej. Procesy te uwalniają energię swobodną do struktur i molekuł rdzenia, warstwy wierzchniej, warstwy Langmuira-Blodgeta i cieczy smarującej oraz w postaci energii chemicznej przy fragmentacji struktur czy molekuł, a też generując cząstki: jak elektrony, kwanty energii jak: fotony, fonony, ekscytony, solitony ... [L. 2]. Formowanie aniono-rodników i procesy tribochemiczne stymulowane są procesami uwalniania energii, cząstek i fragmentów molekuł.

EN

To better understand tribochemical processes occuring under boundary friction conditions one proposed the rule generalizing the hitherto existing anion - radical process [L. 1], for delivering of the energy and electric charge. As the source of energy was pointed friction process, causing deformation processes: of the metal core, surface layer, Langmuir - Blodget layers and the bulk lubricant. These processes release the free energy to structures and molecules of the core, the surface layer, Langmuir - Blodget layer and the lubricant, and in the form of chemical energy at fragmentation of structures or molecules, and additionally also by generating electrons plus quanta of the energy such as: photons, phonons, excitons, solitons ... [L. 2]. The formation of anion-radicals and tribochemical processes stimulated are processes releasing of the energy, small particles and fragments of molecules.