Wyniki wyszukiwania - BazTech

1

Identification of the Thermal Constants of the DPL Heat Transfer Model of a Single Layer Porous Material

Strąkowska Maria, Więcek Bogusław, De Mey Gilbert

Pomiary Automatyka Robotyka

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2021

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R. 25, nr 2

41--46

EN

This paper deals with parameters’ identification of the Dual Phase Lag (DPL) thermal model of a 3D printed porous materials. The experiments were performed for two porous materials with different filling factors. The Laplace transform was applied for the heat transfer equation and together with different optimization methods it allowed to identify the thermal time constants of the DPL model. Several optimization methods were tested with known parameters in order to confirm the correctness of the parameters’ estimation.

PL

Artykuł przedstawia nową metodę identyfikacji parametrów termicznych modelu Dual Phase Lag (DPL) materiałów porowatych drukowanych na drukarce 3D. Eksperymenty przeprowadzono dla dwóch materiałów porowatych o różnych współczynnikach wypełnienia. Do rozwiązania równań przepływu ciepła zastosowano transformację Laplaca, a następnie wykonano optymalizację w celu wyznaczenia wartości parametrów modelu w celu dopasowania ich do eksperymentu. Umożliwiło to identyfikację cieplnych stałych czasowych modelu DPL. Przetestowano również różne metody optymalizacji dla znanych wartości parametrów modelu w celu potwierdzenia poprawności identyfikacji.

2

Co warto wiedzieć o wodzie i jej działaniu na dachach

Patoka Krzysztof

Materiały Budowlane

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2021

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nr 3

34--35

3

The effect of capillary pumping on the course of cleaning porous materials containing liquid contaminants using supercritical fluids – A pore network study

Krzysztoforski Jan, Khayrat Karim, Henczka Marek, Jenny Patrick

Chemical and Process Engineering

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2021

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Vol. 42, nr 4

349-–368

EN

The role of capillary pumping on the course of cleaning porous materials containing liquid contaminants using supercritical fluids was investigated numerically. As a specific process to be modelled, cleaning of porous membranes, contaminated with soybean oil, using supercritical carbon dioxide as the cleaning fluid (solvent) was considered. A 3D pore-network model, developed as an extension of a 2D drying model, was used for performing pore scale simulations. The influence of various process parameters, including the coordination number of the pore network, the computational domain size, and the external flow mass transfer resistance, on the strength of the capillary pumping effect was investigated. The capillary pumping effect increases with increasing domain size and decreasing external flow mass transfer resistance. For low coordination numbers of the pore network, the capillary pumping effect is not noticeable at macro scale, while for high coordination numbers, the opposite trend is observed – capillary pumping may influence the process at macro scale. In the investigated system, the coordination number of the pore network seems to be low, as no capillary pumping effects were observed at macro scale during experimental investigation and macro-scale modelling of the membrane cleaning process.

4

Free vibration and buckling analyses of FG porous sandwich curved microbeams in thermal environment under magnetic field based on modified couple stress theory

Arshid Ehsan, Arshid Hossein, Amir Saeed, Mousavi S. Behnam

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 1

89--111

EN

Porous sandwich structures include different numbers of layers and are capable of demonstrating higher values of strength to weight ratio in comparison with traditional sandwich structures. Free vibration and mechanical buckling responses of a three-layered curved microbeam was investigated under the Lorentz magnetic load in the current study. A viscoelastic substrate was considered and the effect of the thermal environment on its mechanical properties was assessed. The core was composed of the functionally graded porous materials whose properties changed across the thickness based on some given functions. The face sheets were FG-carbon nanotube-reinforced composites and the influence of the placement of CNTs was evaluated on the behavior of the faces. Using the extended rule of mixture, their effective properties were determined. Modified couple stress theory was used to predict the results in the micro-dimension. While the governing equations were derived based on the higher order shear deformation theory and energy method, and mathematically solved via Navier’s method. The results were validated with the previously published works, considering the effects of various parameters. As comprehensively explained in the results section, natural frequencies and critical buckling loads were reduced by enhancing the central opening angle. Moreover, an increase in the porosity coefficient declined the mentioned values, but increasing the CNTs content showed the opposite effect. The outcomes of this study may help in the design and manufacturing of various equipment using such smart structures, making high stiffness to weight ratios more accessible.

5

Udział i znaczenie przepływu lepkiego w nieizobarycznej dyfuzji gazów przez materiały porowate

Boroń Dominika, Tabiś Bolesław

Przemysł Chemiczny

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2020

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T. 99, nr 12

1717--1722

PL

Przedstawiono wyniki ilościowej analizy dyfuzji nieizobarycznej przez materiały makroporowate. Na podstawie uogólnionego modelu gazu zapylonego dokonano oceny udziału przepływu lepkiego. Zaobserwowano zjawisko odwrócenia strumieni molowych, pojawiające się dla pewnej średnicy porów, nawet wówczas gdy dyfuzja następuje przy ustalonej różnicy ciśnień pomiędzy obydwiema stronami membrany. Podano sposób określenia tej średnicy. Zaproponowano uproszczoną metodę obliczania średniej lepkości gazów i dokonano jej oceny. Przedstawione równania modelu są słuszne dla dyfuzji K-składnikowej. Metodę zilustrowano na przykładzie roztworu dwuskładnikowego: argon, metan.

EN

Numerical studies of mass diffusion through porous materials were carried out for a two-component mixt. of Ar and CH4 gases. Using the generalized dusty gas model, an assessment of viscous flow contribution was performed. Reversing of molar fluxes were obsd. for certain pore diam. even at fixed transmembrane pressure difference. A method for detg. the diam. was given. A simplified method for detg. av. viscosity of gaseous mixts. was proposed and assessed. Presented model equations are valid for multicomponent diffusion.

6

The effect of magnetic field dependent viscosity on ferromagnetic convection in a rotating sparsely distributed porous medium - revisited

Prakash J., Kumar P., Manan S., Sharma K. R.

International Journal of Applied Mechanics and Engineering

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2020

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Vol. 25, no. 1

142--158

EN

The effect of magnetic field dependent (MFD) viscosity on the thermal convection in a ferrofluid layer saturating a sparsely distributed porous medium has been investigated by using the Darcy-Brinkman model in the simultaneous presence of a uniform vertical magnetic field and a uniform vertical rotation. A correction is applied to the study of Vaidyanathan et al. [11] which is very important in order to predict the correct behavior of MFD viscosity. A linear stability analysis has been carried out for stationary modes and oscillatory modes separately. The critical wave number and critical Rayleigh number for the onset of instability, for the case of free boundaries, are determined numerically for sufficiently large values of the magnetic parameterM1 . Numerical results are obtained and are illustrated graphically. It is shown that magnetic field dependent viscosity has a destabilizing effect on the system for the case of stationary mode and a stabilizing effect for the case of oscillatory mode, whereas magnetization has a destabilizing effect.

7

Wymiana pary wodnej pomiędzy materiałami budowlanymi a powietrzem w pomieszczeniu

Mijakowski Maciej

Materiały Budowlane

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2019

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nr 1

34--36

PL

W artykule przedstawiono zagadnienia dotyczące transportu (wymiany) wilgoci pomiędzy powietrzem a higroskopijnymi materiałami budowlanymi i wyposażenia wnętrz. Opisano właściwości higroskopijne materiałów porowatych oraz uproszczony model wzajemnego oddziaływania materiału porowatego z otaczającym go powietrzem. Następnie scharakteryzowano wpływ materiałów wyposażenia wnętrz i przegród budowlanych na wilgotność powietrza wewnętrznego. Stanowi to podstawę do określenia możliwości wykorzystania pojemności higroskopijnej budynku do kształtowania warunków wilgotnościowych w pomieszczeniach.

EN

In the paper the issues the regarding transport (exchange) of moisture between air and hygroscopic building materials and interior furnishings have been presented. The hygroscopic properties of porousmaterials and a simplified model of interaction of porous material with the surrounding air have been described. Then, the influence of interior furnishing materials and building partitions on indoor air humidity has been characterized. This set the basis for determining the possibility of using the hygroscopic capacity of the building to shape the humidity conditions in the rooms.

8

Bone tissue loads around titanium femoral implant and coated with porous layer

Bobik G., Żmudzki J., Majewska K.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 90, nr 2

77--84

EN

Purpose: Difference in the mechanical properties of bone and stiffer femoral implant causes bone tissue resorption, which may result in implant loosening and periprosthetic fractures. The introduction of porous material reduces the stiffness of the implant. The aim of the study was to analyse the influence of porous shell of femoral revision implant on bone tissue loading distribution with use the finite element method. Design/methodology/approach: Load transfer in the femur has been investigated using the finite element method (Ansys). Cementless implant models were placed in the anatomical femur model. Femur model included sponge bone and cortical bone. The solid implant was compared with the implant containing porous material in 70% in outer layer with a thickness of 2 mm. Load of 1500 N during gait was simulated. In addition, the forces of the ilio-tibial band and the abductor muscles were implemented, as well as the torque acting on the implant. Findings: Increase of stress for the porous model was found. The underload zones in bone have been reduced. Loading distribution was slightly more favourable, albeit rather in cortical bone. Stress value in cancellous bone around cementless implant margin has increased to a level that is dangerous for bone loss. Stress in the implant was not dangerous for damage. The stress distribution was different in the implant neck zone where the porous shell borne a little less load and high stress was shifted to the stiffer core. Research limitations/implications: Variable conditions for fitting the stem to the bone as well as the friction conditions were not investigated. Practical implications: Stress values in the spongy bone around the insertion edge of the cementless implant are consistent with long-term clinical results of the bone atrophy in 1 and 2 Gruen`s zones around the fully porous implants. Originality/value: The advantage of fully porous coated implant was the decrease of risk of trabecular bone tissue resorption around the implant tip and the increase of risk of trabecular bone tissue resorption around insertion edge of the implant.

9

An oscillatory radiating hydromagnetic internal heat generating fluid flow through a vertcal porous channel with slip and temperature jump

Titiloye E. O., Gbadeyan J. A., Adeosun A. T.

International Journal of Applied Mechanics and Engineering

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2018

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Vol. 23, no. 2

503--519

EN

The present study concerns the natural convective heat generating/absorbing, radiative magnetohydrodynamic, oscillatory fluid flow through a vertical porous channel with slip and temperature jump. The effect of Joule dissipation is taken into consideration while it is assumed that the flow is fully developed. The differential transforms method(DTM) is employed to solve the system of non-linear ordinary differential equations that is obtained from the non-linear partial differential equations governing the flow. Semi analytical solutions of the steady and unsteady part of the flow in the slip flow regime through a vertical porous channel are obtained. The effects of various flow parameters on the velocity and temperature profiles as well as Nusselt and skin friction are presented graphically and discussed. An excellent agreement between the results of this article and those available in the literature validated the presented approach.

10

Zeolitization characteristics of fly ash and its use to manufacture porous materials

David E., Şandru C., Armeanu A.

Archives of Materials Science and Engineering

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2018

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Vol. 90, nr 2

56--67

EN

Purpose: At thermal power plants the fly ash (FA) is stored either through dry or wet disposal systems. These storage practices result in different features for fly ashes, such as their interaction with alkalis and hence the potential of zeolite synthesis will be different. With the aim to demonstrate this, it was conducted some investigations to study the physical, chemical, morphological and mineralogical characteristics of the fly ash residues, then were used to synthesis zeolites by a double stage fusion-hydrothermal method. Design/methodology/approach: The raw and converted fly ash samples were characterized with respect to their composition, crystallinity and morphology, by SEM and XRD analysis. The effects of environment conditions and process parameters on the zeolitization process were studied and analysed. Findings: The analysis of these residues showed that dry ash attains a high cation exchange capacity (CEC) and SiO2 /Al2O3 ratios, which is in agreement to the formation of fly ash zeolites as compared to its counterpart. The experimental results indicate that the fusion temperature does not influence on the synthesis mechanism in range of 500-800 (°C) having only an effect of acceleration. The increasing of alkaline activator/fly ash ratio enhances the zeolitization degree. Research limitations/implications: The scientific basis for the issues on the zeolitization characteristics of fly ash and its use to manufacture porous materials calls yet for further elucidation and development. Practical implications: This study helps to establish the superiority of dry ash over wet ash for synthesizing porous materials and their enhanced quantity and quality. Originality/value: A new route for the fly ash use is demonstrated and this can become an unavoidable task for porous material manufacturing, a viable way to manage this industrial waste and to protect the environment.

11

Experimental and numerical two- and three-dimensional investigation of porosity morphology of the sintered metallic material

Madej L., Legwand A., Mojzeszko M., Chraponski J., Roskosz S., Cwajna J.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 4

1520--1534

EN

A through scale investigation of a porosity shape and morphology after sintering of the Distalloy AB powder is the goal of the paper. First, the classical two dimensional analysis of porosity geometrical aspects is presented with the use of the systematic scanning technique (SST) and the light microscopy (LM). Then, a three dimensional investigation is realized with the non-destructive computed tomography (CT) technique. Advantages and limitations of the approach are evaluated within the work. Finally, to investigate small pores which are beyond the computed tomography resolution, the destructive serial sectioning technique was applied. The developed three dimensional reconstruction algorithm of two dimensional images of obtained cross sections is also presented. Finally, an example of possible practical application of obtained three dimensional digital representation of porosity in sintered samples, during the finite element (FE) modelling of deformation conditions is presented.

12

Modelowanie przepływu cieczy przez materiały porowate o różnej mikrostrukturze

Stec J., Filipek R.

Cement Wapno Beton

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2017

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R. 21/83, nr 6

489--506

PL

W pracy przedstawiono sformułowania modeli transportu w ośrodku porowatym w skali mikro i makro. Jako model mikro ośrodka porowatego przyjęto układ nieruchomych kul reprezentujący ziarna, o rozkładzie dwumodalnym. Na podstawie obliczeń w skali mikro, stosując stacjonarne równanie Stokesa dla cieczy nieściśliwej, wyznaczono maksymalne prędkości oraz przepływy dla poszczególnych mikrostruktur w funkcji promienia małego ziarna oraz porowatości. Obliczono również krętość poszczególnych mikrostruktur. Przedstawiono metodę wyznaczania przepuszczalności układu, która jest uśrednionym parametrem opisującym ośrodek porowaty w skali makro. Zaprezentowana metoda może być stosowana w modelowaniu procesów transportu dla materiałów o rzeczywistej mikrostrukturze.

EN

In the paper authors present the formulation of transport models in porous medium in both micro and macro scale. System of spheres, representing grains, with bimodal radius distribution were used as a model of porous medium in micro scale. Based on calculation in micro scale, using stationary Stokes' equation for incompressible fluid, the maximum velocity and flows were calculated for each microstructure as a function of small grains size as well as porosity. Tortuosity for each microstructure was also calculated. Method for permeability determination, which is an average parameter describing porous medium in macro scale, was presented. Presented method might find application in modelling of transport for materials with real microstructure.

13

Wpływ struktury powierzchni granulatu skrobi termoplastycznej na kinetykę adsorpcji pary wodnej

Muszyński S., Świetlicki M., Oniszczuk T., Kwaśniewska A., Świetlicka I., Arczewska M., Oniszczuk A., Bartnik G., Kornarzyński K., Gładyszewska B.

Przemysł Chemiczny

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2016

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T. 95, nr 4

865--869

PL

Dokonano oceny wpływu struktury powierzchni granulatu skrobi termoplastycznej (TPS) wytworzonej na bazie skrobi pszennej, kukurydzianej i ziemniaczanej na kinetykę adsorpcji pary wodnej. Strukturę tę modyfikowano poprzez zmianę prędkości obrotowej ślimaka ekstrudera, zmieniając gęstość pozorną (objętościową), gęstość rzeczywistą, porowatość całkowitą i względną objętość porów. Badanie prowadzono przez 72 h w środowisku o wilgotności względnej 75,3% w temp. 20°C, wyznaczając przebieg kinetyki adsorpcji pary wodnej w funkcji czasu oraz zmian szybkości adsorpcji pary wodnej w funkcji zawartości wody. Na podstawie przeprowadzonej analizy wykazano wpływ rodzaju użytej skrobi oraz parametrów technologicznych procesu ekstruzji na adsorpcję pary wodnej przez granulat TPS.

EN

Wheat, maize and potato starches were converted to thermoplastic starch (TPS) with glycerol by extrusion, pelletized at changing the speed of extruder screw and studied for apparent d., true d., total porosity, and sp. pore vol. The TPS pellets were studied for water adsorption from air at 20°C and relative humidity 75.3% for 72 h to det. the adsorption kinetics. The lowest hydrophilicity of TPS was found for the pellets extruded at highest speed of extrusion screw (120 rpm).

14

Assessment of process conditions associated with hydrodynamics of gas flow through materials with anisotropic internal structure

Wałowski G., Filipczak G.

Journal of Sustainable Mining

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2016

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Vol. 15, iss. 4

156--169

EN

The results of experimental research concerning the assessment of the permeability of porous materials with respect to gas flow are presented in this paper. The conducted research applied to, among others, chars (acquired from the UCG thermal process) with an anisotropic gap-porous structure and - for comparative purposes - model materials such as pumice and polyamide agglomerates. The research was conducted with the use of a special test stand that enables the measuring of gas permeability with respect to three flow orientations compared with symmetric cubic-shaped samples. The research results show the explicit impact of the flow direction on the permeability of chars, which results from their anisotropic internal structures. The suitability of calculation methods employed to calculate the hydrodynamics of the gas flow through porous materials was also evaluated.

15

Oczyszczanie polimerowych materiałów porowatych przy użyciu płynów w stanie nadkrytycznym

Krzysztoforski J., Henczka M.

Inżynieria i Aparatura Chemiczna

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2016

|

Nr 1

26--27

PL

W pracy przedstawiono wyniki badań doświadczalnych oraz symulacji numerycznych procesu oczyszczania polimerowych materiałów porowatych przy użyciu płynów w stanie nadkrytycznym. Zbadano wpływ parametrów operacyjnych na przebieg procesu oraz opracowano i wstępnie zweryfikowano model matematyczny, który może być wykorzystany do symulacji i optymalizacji procesu oraz do projektowania aparatury wysokociśnieniowej. Wykazano, że płyny w stanie nadkrytycznym stanowią efektywne rozpuszczalniki w procesach oczyszczania polimerowych materiałów porowatych.

EN

Experimental results and numerical simulations of porous polymer material cleaning process using supercritical fluids are presented in the paper. An influence of process parameters on the process course was investigated and a mathematical model was developed and validated. The model can be used for process investigation and optimization, and also for high pressure equipment design. It was proven that supercritical fluids are effective solvents in porous polymer material cleaning processes.

16

Gazoprzepuszczalność materiałów porowatych o anizotropowej strukturze

Wałowski G., Filipczak G.

Inżynieria i Aparatura Chemiczna

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2016

|

Nr 6

245--250

PL

Przedstawiono wyniki badań doświadczalnych w zakresie oceny przepuszczalności materiałów porowatych w odniesieniu do przepływu gazu. Badaniom podano karbonizaty o anizotropowej strukturze szczelinowo-porowatej, a także - celem porównania - materiały modelowe typu pumeks i spieki poliamidowe. Badania wykonano na specjalnie do tego celu przygotowanym stanowisku pomiarowym, umożliwiającym pomiar gazoprzepuszczalności względem trzech orientacji przepływu, odniesionych do symetrycznych próbek o kształcie sześciennym. Wyniki pomiarów wskazują na wyraźny wpływ kierunkowości przepływu na przepuszczalność karbonizatów, co wynika z anizotropowej ich struktury wewnętrznej. Zdefiniowano współczynnik przepuszczalności tego typu materiałów oraz dokonano eksperymentalnej oceny wartości tego współczynnika względem strumienia gazu oraz całkowitego spadku ciśnienia na porowatym złożu. Dokonano oceny przydatności metod obliczeniowych charakteryzujących hydrodynamikę przepływu gazu przez porowate materiały oraz wskazano na możliwość numerycznego odwzorowania geometrii przepływowej materiałów o krętej strukturze szkieletowej.

EN

The paper presents results of experimental studies dealing with the assessment of porous materials permeability with respect to the gas flow. The study was carried out for coal-char material with an anisotropic slotted structure, and for comparison, for model materials such as pumice and sintered polyamide. The tests were performed in a specially prepared measuring setup allowing the measurement of gas permeability at three flow directions with respect to porous samples of cubic shape. The measurement results demonstrated an effect of gas flow direction on chars permeability caused by their anisotropic internal structure. The permeability coefficient was defined, its value with respect to gas flux was experimentally evaluated and the total pressure drop across the porous bed was determined. An assessment of usefulness of computational methods characterizing the hydrodynamics of gas flow through porous materials is presented. Additionally, the possibility of numerical mapping of flow geometry of backbone tortuous structure materials is considered.

17

Pomiary sorpcyjne współczynnika dyfuzji wilgoci różnego rodzaju zapraw

Garbalińska H., Majkowski B.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2015

|

z. 62, nr 2

89--98

PL

W referacie przedstawiono możliwość wykorzystania niestacjonarnych pomiarów sorpcyjnych do określenia współczynnika dyfuzji Dm porowatych materiałów budowlanych. Badaniami objęto trzy różne zaprawy: cementową, cementowo-wapienną i modyfikowaną. Eksperyment zrealizowano w 18 klimatach – przy trzech temperaturach: 5, 20, 35°C i przy sześciu poziomach wilgotności względnej powietrza φ. Na podstawie uzyskanych wyników badań sorpcyjnych wyznaczano dla poszczególnych zapraw wartości współczynnika dyfuzji wilgoci odpowiadające różnym temperaturom i różnym poziomom sorpcyjnego zawilgocenia. Przedstawione w referacie obliczenia współczynników dyfuzji Dm bazowały na procedurach typu √t i typu logarytmicznego. Otrzymane rezultaty pozwoliły ocenić użyteczność obydwu procedur w odniesieniu do testowanych materiałów. We wszystkich cyklach i w przypadku każdej z zapraw uzyskiwano zbliżone wartości współczynników Dm( √t) i Dm(ln), co pozwala rekomendować obydwie procedury jako porównywalne. Przeprowadzone badania pozwoliły ponadto ocenić wpływ zawartości wilgoci na wielkość współczynników dyfuzji. Stwierdzono występowanie jednoznacznej tendencji w odniesieniu do każdej temperatury i każdej z badanych zapraw. Zaobserwowano wzrost wartości Dm wraz ze zwiększaniem się wilgotności względnej do poziomu 50%. Dla tego poziomu zawilgocenia materiału współczynnik dyfuzji osiągał wartość maksymalną. Następnie wartość tego współczynnika spadała stopniowo w miarę wzrostu wilgotności. Stwierdzono, że w najszerszym zakresie wilgotności, tj. przy φ ≈ 96% współczynniki dyfuzji osiągają wartość minimalną, odpowiadającą zakresowi najniższych wilgotności. Przeprowadzone badania pozwoliły ocenić nie tylko wpływ wilgotności, ale także wpływ temperatury na wyznaczane współczynniki dyfuzji. Obydwie zastosowane metody wykazały znaczący wpływ tego czynnika na wyznaczane wartości współczynników dyfuzji Dm.

EN

The paper presents possibilities of application of non-stationary sorption measurements to determine the diffusion coefficient Dm of porous building materials. The research covers three different mortars: cement mortar, cement-lime mortar and modified mortar. The experiment was conducted in 18 different types of climate, at the three following temperatures: 5°C, 20°C and 35°C, and at six relative humidity levels φ. Basing of the results of sorption measurements, values of diffusion coefficient Dm were calculated for different mortars, and the particular values obtained referred to various temperatures and various levels of sorption moisture. Calculations of coefficient Dm shown in this paper were based on √t-type and logarithmic-type procedures. The obtained results allowed to evaluation the usability of two procedures for the tested materials. In all cycles and for each of the mortars, similar values of coefficients Dm(√t) and Dm(ln) were observed, which enables to recommend the both procedures as comparable ones. Moreover, the research allowed to assess the influence of moisture content on diffusion coefficient values. A clear tendency appeared for each temperature and each of the mortars researched. There was observed increase of the Dm value together with the rise of relative humidity up to the level of 50%. For this level of moisture in the material the diffusion coefficient reached the maximum value. After that, the value of the coefficient was gradually decreasing together with increase of moisture. It was concluded that in the broadest humidity range, i.e. at φ ≈ 96%, diffusion coefficients reach the minimum values referring to the range of lowest level of moisture. The conducted research allowed to assess not only the influence of moisture but the impact of temperature as well. The both methods showed considerable influence of this factor on Dm values.

18

Applications of newly developed nanostructural and microporous materials in biomedical, tissue and mechanical engineering

Dobrzański L. A.

Archives of Materials Science and Engineering

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2015

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Vol. 76, nr 2

53--114

EN

Purpose: The purpose of the paper is to present the main results of own research in 3 principal aspects indicating that the research is up to date and modern. This relates to nanotechnologies, modern biomedical materials and rapid manufacturing techniques used for the production of, in particular, microporous materials applied for medical and dental purposes. The paper comprises the explanation of structural mechanisms and phase transformations taking place in newly created engineering nanostructural and microporous materials under the influence of the applied, advanced technological processes newly developed, and especially nanotechnological processes, using the most modern scientific and research equipment being at disposal of modern materials engineering, in particular with the common use of high-resolution transmission electron microscopy (HRTEM). The results of investigations into the formation of the structure and surface properties results according to a different thickness scale of coatings or surface zone, from several hundred nanometres to several millimetres, are presented in the paper, including PVD and CVD coatings and laser treated surface on the steels and light alloys substrates. The paper also describes the nanostructural effects in solid materials, and especially the counteraction of cracking of new-developed high-manganese austenite steels Fe-Mn-Si-Al by twinning or/and martensitic transformation induced by the cold plastic deformation. The article also outlines the results of research of the development of special micro and nanocomposite materials designed mainly for use in regenerative medicine and regenerative dentistry. The studies of the structure and the properties of newly obtained materials and originally developed technologies are included to present the author’s contribution into materials science, nanotechnology, surface engineering and biomedical engineering including the usefulness of the newly developed nanoengineering materials and their applicability, in particular, in regenerative medicine, as well as tissue engineering. The described outcomes of the research constitute a basis for creating, apart from rigid porous implant-scaffolds, an innovative generation of rigid and elastic biological-engineering composite materials for regenerative medicine. Design/methodology/approach: The article discusses the key aspects of own research performed over the last decade in scope of nanotechnologies, modern biomedical materials and rapid manufacturing techniques used for the fabrication of, in particular, microporous materials applied for medical and dental purposes. The conditions for the performance of the research according to the scope mentioned were ensured by implementation of investment projects for constructing and equipping research and didactic laboratories in scope of nanotechnology, technologies of material processes and computational materials science, including LANAMATE (2010-2014) and MERMFLEG (2010-2013), and also BIOFARMA (2010-2012). Practical implications: The obtained materials and technologies are of high practical importance, which was confirmed in many cases with the results of laboratory tests and investigations at a semi-technical scale, and in some cases with the initiation of implementation works. The results of research in scope of bioengineering and dental engineering may find their applications in tissue engineering, in bone surgery, for threedimensional tissue scaffolds and in dentistry or oncology, to replace the natural tissue removed because of a cancer with the possibility of applying a therapeutic agent. Originality/value: The present paper is the original report from a personal own research and explains the concept, scope and results of own research of a new obtained microporous and nanostructural materials and coatings, including hybride solid-porous products and newly obtained materials processing and additive technologies. Some of the mentioned research results are protected by patents or patent applications, and many of them were awarded over 60 prizes and medals at international fairs of innovation, invention and rationalisation in many countries.

19

The novel semi-biodegradable interpenetrating polymer networks based on urethane-dimethacrylate and epoxy-polyester components as alternative biomaterials

Barszczewska-Rybarek I., Jaszcz K., Jurczyk S., Chladek G

Acta of Bioengineering and Biomechanics

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2015

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Vol. 17, no. 3

13--22

EN

Purpose: This paper presents the pilot study aimed at the development of new full interpenetrating polymer networks based on urethane-dimethacrylate and biodegradable epoxy-polyester as the proposition of new biomaterials with gradually emerging porosity. Methods: The urethane-dimethacrylate monomer was obtained from 4,4’-methylenebis(phenyl isocyanate) and tetraethylene glycol monomethacrylate. The redox-initiating system was employed for its radical polymerization. The epoxy-polyester was produced by oxidation of the polyester, synthesized from succinic anhydride and allyl glicydyl ether. It was cured in a step-growth process with biogenic, aliphatic amine – spermidine. The mixtures of both monomers with adequate curing agents were room temperature polymerized. The hardened materials were characterized for damping behavior and dynamic modulus, hardness, water sorption, the course of hydrolytic degradation as well as the morphology – before and during the degradation process. Results: The cured materials revealed the nonporous, dense morphology. In the hydrolytic environment, the epoxy-polyester network degraded and the porous urethane-dimethacrylate scaffold remained. The epoxy-polyester appeared to prevent the urethane-dimethacrylate from attaining a high degree of conversion, even if the polymerization rate and the molecular mobility of the latter one are higher than those of the epoxy-polyester. The most homogeneous material with the best physico-mechanical properties was obtained when the urethane-dimethacrylate content was smaller than the epoxy-polyester content, respectively 25 and 50 wt%. Conclusions: The system presented in this work could be useful in tissue engineering, where at the beginning of the tissue regeneration process it would meet the implant mechanical properties and then would deliver its porosity, facilitating the tissue regeneration process.

20

Przepływy roztworu w kontakcie materiału porowatego i włóknistego

Kubik J., Hudziak H.

Roczniki Inżynierii Budowlanej

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2014

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z. 14

81--84

EN

The paper presents the comparison of the geometrical properties of porous material and fibrous material with the same fiber diameters and the radius of capillaries. The comparison shows that the geometrical configuration of the fibrous material compared to the porous material induce the effect of suction of the liquid at the contact of these two materials.