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1

An iterative approach for solving fractional order Cauchy reaction-diffusion equations

Kumar Manoj

Journal of Applied Mathematics and Computational Mechanics

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2023

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Vol. 22, nr 3

19--32

EN

Reaction-diffusion equations are vitally important due to their role in developing sturdy models in various scientific fields. In the present work, we address an algorithm of the Daftardar-Gejji and Jafari method for solving the nonlinear functional equations of the form ψ = f +L(ψ) + N(ψ). Further, we employ this algorithm to solve Caputo derivative-based time-fractional Cauchy reaction-diffusion equations. We obtain solutions in a series form that converges to a closed form. Furthermore, we perform numerical simulations for the various values of the order of fractional derivatives. The computational procedure of the proposed algorithm is not burdensome. However, it is time-efficient and can easily be implemented using a computer algebra system.

2

Memory dependent triple-phase-lag thermo-elasticity in thermo-diffusive medium

Yadav Anand Kumar, Singh Aarti, Jurczak Paweł

International Journal of Applied Mechanics and Engineering

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2023

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Vol. 28, no. 4

137--162

EN

The objective of the paper is to look at the propagation and reflection of plane waves in a thermo-diffusion isotropic medium. The reflection of plane waves in a thermo-diffusion medium was investigated in this study with reference to triple phase lag thermo-elasticity. The memory dependent derivative (MDD) is applied for this investigation. The fundamental equations are framed and solved for a particular plane. The four plane waves that are propagating across the medium are, shown namely: longitudinal displacement, P-wave, thermal diffusion T-wave, mass diffusion MD-wave and shear vertical SV-wave. These four plane wave velocities are listed for a specific medium, illustrating the impact of the diffusion coefficient and are graphically represented. Expressions for the reflection coefficient for the incidence plane wave are produced from research on the reflection of plane waves from the stress-free surface. It should be noted that these ratios are graphically represented and shown when diffusion and memory dependent derivative (MDD) factors are in play. The new model is relevant to many different fields, including semiconductors, earth- engineering, and electronics, among others, where thermo-diffusion elasticity is significant. Diffusion is a technique that can be applied to the production of integrated circuits, MOS transistors, doped polysilicon gates for the base and emitter in transistors, as well as for efficient oil extraction from oil reserves. Wave propagation in a thermos-diffusion elastic media provides crucial information about the presence of fresh and enhanced waves in a variety of technical and geophysical contexts. For experimental seismologists, developers of new materials, and researchers, this model might be useful in revising earthquake estimates.

3

Use of solar energy in the technology of fruit drying

Korobka Serhiy, Boyarchuk Vitaliy, Syrotiuk Valerii, Syrotyuk Serhiy, Stukalets Igor, Golovko Volodymyr, Syrotyuk Hanna, Jakubowski Tomasz, Giełżecki Jan

Przegląd Elektrotechniczny

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2022

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R. 98, nr 6

37--44

EN

Companies in the agri-food industry of Ukraine are trying to rationally manage all forms of energy (including solar energy) needed to implement the production process. The study investigated the process of drying plant material (fruit) based on the use of solar energy (and the intensification of this process). The present process uses a combination of an air collector and a drying chamber. The measurable effect of the performed tests is the development of diagnostic techniques for heat transfer with alternative diffusion and moisture transfer potentials (the experiment was performed at the temperature of 25-60⁰C, drying time was 50-74 hours). The method is offered to calculate the diffusion and moisture transfer when drying the fruit in a solar dryer. The method enables the diagnosis of heat exchange processes and the analysis of the mathematical model of heat exchange processes [1]. The results of the research (analytical and experimental) indicate the possibility of intensifying the fruit drying process based on the solar dryer. The unit energy consumption during fruit drying in a solar dryer is reduced by 3-3.7 MJ/kg in relation to the currently used convection drying devices.

PL

Firmy z branży rolno-spożywczej Ukrainy starają się racjonalnie gospodarować wszystkimi formami energii (w tym energią słoneczną) potrzebną do realizacji procesu produkcyjnego. W pracy zbadano proces suszenia materiału roślinnego (owoców) w oparciu o wykorzystanie energii słonecznej (i intensyfikację tego procesu). Niniejszy proces wykorzystuje połączenie kolektora powietrznego i komory suszącej. Wymiernym efektem przeprowadzonych badań jest opracowanie technik diagnostycznych wymiany ciepła o alternatywnych potencjałach dyfuzji oraz przenoszenia wilgoci (doświadczenie przeprowadzono w temperaturze 25 ⁰C – 60 ⁰C, czas suszenia 50-74 godz.). Metoda oblicza dyfuzję i transfer wilgoci podczas suszenia owoców w suszarce słonecznej. Metoda umożliwia analizę procesów wymiany ciepła oraz modelu matematycznego procesów wymiany ciepła [1]. Wyniki badań (analitycznych i eksperymentalnych) wskazują na możliwość intensyfikacji procesu suszenia owoców w oparciu o suszarkę słoneczną. Jednostkowe zużycie energii podczas suszenia owoców w suszarni solarnej zmniejsza się o 3 MJ/kg - 3,7 MJ/kg w stosunku do obecnie stosowanych urządzeń do suszenia konwekcyjnego.

4

Strouhal number effects on dynamic boundary layer evolution over a wedge surface from initial flow to steady flow: analytical approach

Bachiri Mohamed, Bouabdallah Ahcen

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 4

26--39

EN

The present work studies the effects of the physical parameter characterizing the laminar flow regime, namely the Strouhal number, on the evolution of the unsteady dynamic boundary-layer developed along a wedge surface. Similarity method is used to transform unsteady momentum equation to dimensionless form. Using superposition method between diffusion and convective flows solutions, an ad hoc velocity profile formula is proposed. The obtained results confirm perfectly the numerical data given by Blasius, Falkner-Skan and Williams-Rhyne for all Strouhal numbers. A new accurate analytical function of the local skin friction is established for all time values and for different wedge surface directions. In order to give further clarification on the flows evolutions from diffusion flow to convective flow, in the whole space domain, new skin friction coefficient curves are plotted for all Strouhal numbers and for different wedge surface directions.

5

Water absorption behavior and its effect on Charpy impact test of jute yarn reinforced polyester composites

Djeghader Djamel, Redjel Bachir

Composites Theory and Practice

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2022

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R. 22, nr 2

65--71

EN

Plates of bidirectional jute/polyester composite material were manufactured by the contact molding method. These plates were cut to form notched test pieces 80x15x4 mm and immersed in water (1, 10, 30, 90, 180 and 270 days) in order to study the impact behavior of this material. The studied composite exhibited a water saturation limit after an immersion period of approximately 30 days, with Fickian diffusion of water within the material. Williams’ method based on linear elastic fracture mechanics was used to calculate impact toughness GIC, which is due to the intrinsic characteristics of the material.

6

Effect of chemical composition of boriding agent on the optimization of surface hardness and layer thickness on AISI 8620 steel by solid and liquid boriding processes

Kul Mehmet, Yılmaz Yasin, Oskay Kürşad Oğuz, Kumruoğlu Levent Cenk

Advances in Materials Science

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2022

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Vol. 22, nr 3(73)

14--22

EN

Surfaces of cam shafts made of AISI 8620 steels were hardened by boriding processes in both solid and liquid mediums. Various chemical agents were used to achieve boride layers on the surfaces of the cam shafts in these processes. It was aimed to examine effects of the chemical agents on microhardness and thickness of the boride layers obtained. It was concluded that a bath composition of 5% B4C-90% SiC-5% KBF4 was appropriate for the hardest and thickest boride layer achieved in the solid medium, and a composition of 70% Na2B4O7-30% B4C in the liquid medium.

7

Influence of diffusion and impedence parameters on wave propagation in thermoelastic medium

Kaushal Sachin, Kumar Rajneesh, Parmar Kulwinder

International Journal of Applied Mechanics and Engineering

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2021

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Vol. 26, no. 4

99--112

EN

The aim of the present paper is to study the impact of diffusion and impedance parameters on the propagation of plane waves in a thermoelastic medium for Green and Lindsay theory (G-L) and the Coupled theory (C-T) of thermoelasticity. Results are demonstrated for impedance boundary conditions and the amplitude ratios of various reflected waves against the angle of incidence are calculated numerically. The characteristics of diffusion, relaxation time and impedence parameter on amplitude ratios have been depicted graphically. Some cases of interest are also derived from the present investigation.

8

Alternative methodology to determine effective coefficient of methane diffusion in coal

Koptoń Henryk

Journal of Sustainable Mining

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2020

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Vol. 19, iss. 2

88--95

EN

The article presents the results of research in to the development of an alternative method of determining the effective coefficient of methane diffusion in coal, based on a mathematical model following Fick's second law. The research was conducted based on the recorded courses of methane sorption kinetics in coal samples obtained in laboratory conditions with the precise gravimetric sorption system IGA-001. The value of the coefficient was treated as an element tuning the model in such a way that the average relative error of the ex post was as small as possible. Model verification indicated the correctness of its assumptions. The development of a more accurate methodology to determine the effective coefficient of methane diffusion in coal will enable the verification of the models applied in order to describe the physical and chemical mechanisms of the methane desorption natural phenomenon. It will also pave the way for further research aimed at the determination of: the gas bearing capacity of coal seams, the degree of degassing of seamswhich results from the mining operations being conducted; or to what extent it is possible to degas the deposits.

9

Przyczyny zawilgacania budynków

Monczyński Bartłomiej

Izolacje

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2020

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R. 25, nr 1

88--90, 92--93

PL

Przedmiotem artykułu są zagadnienia dotyczące hydroizolacji budynków. Omówiono w nim warunki gruntowo-wodne rzutujące na dobór odpowiednich do nich izolacji. Przeanalizowano magazynowanie i transport wody w materiałach porowatych, a także zjawiska sorpcji, kondensacji powierzchniowej i dyfuzji pary wodnej.

EN

This paper concerns the issues related with waterproof insulation of buildings. It also describes the soil and water conditions that affect the selection of proper insulation materials. Storage and transfer of water in porous materials, as well as sorption, surficial condensation and water vapour diffusion have been analysed.

10

On the go-and-stop motion of the discontinuous precipitation front

Chronowski M., Zięba P.

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 2

73--79

EN

The growth of lamellar structure during discontinuous precipitation occurs frequently by so-called go-and-stop fashion. The results of simulation combined with the changes of Cahn’s parameter C revealed two types of such motion. The process takes place in the successive stages which can be distinguished judging from the value of C parameter. For lower values of linear growth rate (v = 10÷20 nm/s) and smaller α lamella thickness (100÷200 nm), the full cycle with relaxation takes 4–6 s. The faster movement of the reaction front (v = 30 nm/s) resulted in dramatic decrease of the full cycle to τtotal = 0.8 s. The same behavior is observed if the α lamella thickness increases beyond 200 nm at constant v equal to 10 nm/s. Both predicted types of go-and-stop motion can experimentally be observed during growth or dissolution of discontinuous precipitates. What is the reason that particular type prevails is unknown, and this is invitation for further studies especially using high-resolution transmission electron microscope operating in in situ mode.

11

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.

12

Microstructure and hardness of Pyrowear 53 steel after low-pressure vacuum carburizing at 921°C

Wojtyczka Artur, Iżowski Bartosz

Advances in Manufacturing Science and Technology

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2020

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Vol. 44, nr 4

109--112

EN

The present paper studies and analyzes the low-pressure vacuum carburizing of Pyrowear 53 steel. The carburizing was performed at 921°C. The results after the completion of the treatment process are presented, i.e. microstructure of the surface layer and hardness. The results confirm that carburizing can be effectively used in hardening of the steel.

13

Value creation through management accounting practices in large Thai manufacturing companies

Terdpaopong Kanitsorn, Visedsun Nimnual, Nitirojntanad Kanibhatti

Polish Journal of Management Studies

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2019

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Vol. 19, No. 2

395--406

EN

This research explores the extent to which various management accounting practices (MAPs) have been implemented in large Thai manufacturing companies. Although IFAC 1998, which describes management accounting evolution, has been studied extensively in the two decades since its release, MAPs and their diffusion for business value creation has received relatively little attention. This study uses a survey questionnaire to collect information on this subject. Of the 1,500 companies that received the survey, 205 provided usable, complete responses, for a 13.67% response rate. Cluster analysis is used to group a set of data objects into four clusters with hierarchical agglomerative methods, and a discriminant analysis is used to assure the cluster analysis classification’s accuracy. The results show that the respondents used Budgeting for product cost controlling the most. We also discovered that the new, advanced MAPs are used increasingly among many large Thai companies. MAPs are used to create value for large Thai companies, but not yet to the highest stage, based on the IFAC evolution model. Adoption is still far behind compared to the pace of change in production processes, especially in light of increasing competition on the global level.

PL

Niniejsze badanie bada zakres, w jakim różne praktyki rachunkowości zarządczej (MAP) zostały wdrożone w dużych tajskich firmach produkcyjnych. Chociaż IFAC 1998, który opisuje ewolucję rachunkowości zarządczej, był intensywnie badany w ciągu dwóch dziesięcioleci od jego wydania, MAPs i ich rozpowszechnianie w celu tworzenia wartości biznesowej zyskały stosunkowo mało uwagi. To badanie wykorzystuje kwestionariusz do zbierania informacji na ten temat. Spośród 1500 firm, które otrzymały ankietę, 205 dostarczyło użytecznych, kompletnych odpowiedzi za wskaźnik odpowiedzi 13,67%. Analiza skupień jest używana do grupowania zbioru obiektów danych w cztery klastry z hierarchicznymi metodami aglomeracyjnymi, a analiza dyskryminacyjna jest używana do zapewnienia dokładności klasyfikacji analizy skupień. Wyniki pokazują, że respondenci najczęściej stosowali budżetowanie do kontrolowania kosztów produktu. Wskazano również, że nowe, zaawansowane MAP są coraz częściej wykorzystywane przez wiele dużych tajskich firm. MAPy są wykorzystywane do tworzenia wartości dla dużych tajskich firm, ale jeszcze nie do najwyższego etapu, w oparciu o model ewolucji IFAC. Zastosowanie wciąż pozostaje daleko w tyle w stosunku do tempa zmian w procesach produkcyjnych, zwłaszcza w świetle rosnącej konkurencji na poziomie globalnym.

14

Studies of silver diffusion into soda-lime glass using analysis of plasmon evolution

Nocuń Marek, Środa Marcin, Jedliński Jerzy, Lipień Krzysztof

Materiały Ceramiczne

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2019

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T. 71, nr 3

220--227

EN

Silver diffused into microscope slides made of an AgNO3/NaNO3 alloy. Surface plasmon resonance of the Ag nanoparticle was analyzed by optical spectroscopy. The mechanism of silver crystal growth was analyzed by scanning electron microscopy (SEM) equipped with X-ray energy diffraction (EDS) technique. The evolution of local surface plasmon resonance was studied by UV-VIS spectroscopy. Samples were also analyzed by X-ray photoelectron spectroscopy (XPS) and ellipsometry.

PL

Srebro dyfundowało do szkiełek mikroskopowych ze stopu AgNO3/NaNO3. Powierzchniowy rezonans plazmonowy nanocząstki Ag analizowano za pomocą spektroskopii optycznej. Mechanizm wzrostu kryształów srebra analizowano za pomocą skaningowej mikroskopii elektronowej (SEM) wyposażonej w technikę dyfrakcji energii rentgenowskiej (EDS). Ewolucję lokalnego rezonansu plazmonowego powierzchni badano za pomocą spektroskopii UV-VIS. Próbki analizowano również za pomocą rentgenowskiej spektroskopii fotoelektronowej (XPS) i elipsometrii.

15

Efficiency of MgO activated GGBFS and OPC in the stabilization of highly sulfidic mine tailings

Sarkkinen Minna, Kujala Kauko, Gehör Seppo

Journal of Sustainable Mining

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2019

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Vol. 18, iss. 3

115--126

EN

MgO activated ground granulated blast furnace slag (GGBFS) is a form of alkali-activated composite, which is successfully used as a binder in the stabilization of highly sulfidic mine tailings. The aim of this study was to compare alkali activated composite (AAC) and ordinary Portland cement (PC) as stabilization agents, as well as their efficiency to stabilize sulfidic tailings and the results of three different diffusion and leaching methods. The Life Cycle Assessment (LCA) method was used to compare the environmental impacts of the binders. The lab-scale program covered hydraulic conductivity, compression strength, and freeze-thaw resistance tests of the stabilized tailings. The results indicate that the hydraulic conductivity (6.08 · 10-9 m/s) and compressive strength (11.5 MPa at 28 days) of AAC were better in comparison, if the corresponding amount of PC (2.04 · 10-8 m/s and 10.3 MPa at 28 days) was used. LCA shows clear ecological benefits when using AAC instead of PC in terms of lower global warming potential. Diffusion and leaching tests indicated better immobilization efficiency of AAC than PC concerning As, Cr, Cu, Ni, Se, Zn, and especially Mo. In comparison with plain tailings, AAC stabilization reduced leaching of As, Cr, Cu, Mo, Ni, Pb, Se, Zn, Cl, and SO4 better than PC.

16

Transport of Organic Dyes in Systems Containing Humic Acids

Rybarik Jan, Sedlacek Petr, Klucakova Martina

Inżynieria Mineralna

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2019

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R. 21, nr 1

159--162

EN

This work is focused on transport organic dyes in systems containing humic acids as active reaction agent. Methylene blue was used as a model organic dye which can behave as pollutant and influence many processes in nature. Transport of pollutants in nature is strongly affected by interactions with humic acids or natural organic matter. Their influence is dependent on affinity of pollutant to content and strength of active binding sites. Two different humic samples are used in this study in order to compare their properties on transport of organic dye. Both humic acids are used in original extracted form as well as in the form of samples with selective blocked functional groups.

PL

Niniejsza praca koncentruje się na transporcie barwników organicznych w systemach zawierających kwasy huminowe jako środek aktywny. Błękit metylenowy wykorzystano jako modelowy barwnik organiczny, który może zachowywać się jak substancja zanieczyszczająca i wpływać na wiele procesów w przyrodzie. Na transport zanieczyszczeń w przyrodzie silnie wpływają interakcje z kwasami huminowymi lub naturalną materią organiczną. Ich wpływ zależy od powinowactwa substancji zanieczyszczającej do zawartości i siły aktywnych miejsc wiązania. W badaniu tym zastosowano dwie różne próbki humusowe w celu porównania ich właściwości w transporcie barwnika organicznego. Oba kwasy humusowe stosuje się w oryginalnej postaci ekstrahowanej, jak również w postaci próbek z selektywnie zablokowanymi grupami funkcyjnymi.

17

Oxidation kinetics of Zircaloy-4 alloy at 673 K determined by GDOES technique

Trybuś Bartłomiej, Olive Jean-Marc, Zieliński Andrzej

Inżynieria Materiałowa

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2019

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Vol. 40, nr 2

34--38

EN

Oxidation of zirconium alloys is a process that takes place during the operation of nuclear reactors and is essential for assessing the durability of fuel claddings. The present study was aimed to determine the oxidation kinetics of the Zircaloy-4 alloy using GDOES (glow discharge optical emission spectroscopy) at temperature 673 K corresponding to the conditions of use of fuel pellets. The tests were performed on non-oxidized samples as well as after their oxidation for 0.5, 2, 15 and 48 h. Oxygen layer growth was also investigated by thermogravimetric analysis after oxidation for 0.5 h. The naturally generated oxide at room temperature, designated as non-oxidized, had a thickness of 23±2 nm. After 2 h oxidation, an oxide possessing a thickness of 42±4 nm with about 155 nm of oxygen traces was observed. Oxidation for 15 h resulted in formation of an oxide with a thickness of 130±10 nm with a transition distance to the pure alloy of 240 nm. Finally, a layer with a thickness of 235±10 nm appeared after oxidation for 48 h, while the distance after which the measurement included only a pure alloy without the oxygen traces, was about 310 nm. The results show that oxidation can be described by the exponential kinetic equation, that has the parabolic form after 15 or 48 h of oxidation, which well fits the previous results. However, at shorter oxidation times the kinetic equation has the quasi-parabolic form (n < 2). The reason for changing the form of the equation can be attributed to the effect of defective crystalline structure on oxygen diffusion in the oxide layer as the porosity, crevices and cracks.

PL

W wielu pracach opisano masę tlenku cyrkonu powstającego podczas utleniania równaniem parabolicznym, ale według części autorów zależność ta lepiej daje się opisać równaniem kubicznym. Kinetyka opisana przez tę ostatnią zależność dowodzi, że proces dyfuzji atomów tlenu, który determinuje szybkość tworzenia się tlenku, nie jest procesem homogenicznym zachodzącym w idealnym ciele stałym, ale przebiega głównie na granicy ziaren. Celem pracy było określenie zależności ilościowych między czasem utleniania a grubością warstw tlenków w stosunkowo niskiej temperaturze 673 K, odpowiadającej normalnym warunkom pracy reaktorów jądrowych, za pomocą metody GDOES (optyczna spektrometria emisyjna z wyładowaniem jarzeniowym) rzadko stosowanej do badań takich procesów.

18

Triple diffusive convection of a non-Newtonian fluid under the combined effect of compressibility and variable gravity

Aggarwal A. K., Dixit D.

International Journal of Applied Mechanics and Engineering

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2019

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Vol. 24, no. 4

1--11

EN

In this paper, triple diffusive convection in a Rivlin-Ericksen fluid layer, which is permeated with suspended particles in the porous medium under the effect of compressibility and variable gravity, is investigated. Linear stability theory and normal mode analysis have been used to study the problem under consideration. It is observed that, for stationary convection, suspended particles, compressibility and medium permeability have destabilizing/stabilizing effects under certain conditions. The variable gravity parameter destabilizes the system whereas stable solute gradients have a stabilizing effect.

19

Activated carbon adsorption behaviour of toluene at various temperatures and relative humidity

Görgülü Adnan, Yağli Hüseyin, Koç Yildiz, Koç Ali, Baltacioğlu Ertuğrul

Environment Protection Engineering

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2019

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Vol. 45, nr 1

111--126

EN

Filtration plays a major role in managing the rapid increase of environmental pollution and deterioration of atmospheric air quality. One of the most damaging noxious gases in the atmosphere is toluene, which is a common gas that appears in crude oil and is used in various production processes. The adsorption behaviour of activated carbon was examined in dependence of the concentration, temperature and relative humidity. The results showed that increasing air temperature decreased the time to reach the maximum saturation ratio, which occurred due to the increasing pore diffusion coefficient and pore diffusion rate.

20

Zróżnicowanie rozwoju społeczno-gospodarczego w polskich samorządach w latach 2004-2016

Pietrzykowski Maciej

Biuletyn Komitetu Przestrzennego Zagospodarowania Kraju PAN

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2019

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No 274

167--188

EN

The aim of the article is to analyse the spread and diffusion of socio-economic development in Poland in 2004-2016, while considering spatial aspects. Using the linear ordering method in the non-pattern version, a synthetic development measure for all municipalities in Poland was built based on a set of 77 features illustrating various socio-economic aspects, reduced to 25 features. For the measure constructed in this way, the convergence of the beta and sigma type has been examined, divided into 3 groups of municipalities (rural, urban and urban-rural), as well as in regional division. Using the methods of spatial econometrics, the occurrence of spatial effects was examined, in particular the attention was paid to the relationship between the processes of spreading development and spatial forms of diffusion of development. The analysis also allowed to determine the strength of local impacts of spatial connections between individual municipalities.