Nowe zasoby w kolekcji Artykuły http://suw.biblos.pk.edu.pl/ Biblioteka Politechniki Krakowskiej lipinska@biblos.pk.edu.pl 60 <![CDATA[Housing environment in teaching architecture and spatial management students – methodology and effects]]> Wed, 27 May 2020 12:45:58 +0200 Schneider-Skalska, Grażyna
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Abstrakt: Shaping the housing environment is a political, social, economic and spatial problem. Until recently, issues related to this area were covered in the Faculty of Architecture at Cracow University of Technology (FA-CUT) in the architecture study curriculum. The appearance of the study on spatial management at the FA-CUT resulted in the need to include housing environment in the curriculum of spatial management. Graduates of these studies are specialist engineers who will make important planning, economic and social decisions. They will have to cooperate with architects. A comparative analysis of the expected learning outcomes and methodology of teaching the subject shaping the housing environment, as well as diploma theses in this field allows demonstrating the convergence, differences and complementarity of knowledge and skills of graduates of both fields. In this article, the author outlines this issue on the example of programmes, course projects and diploma theses made at the FA-CUT in 2017-2019. The number of hours of theory and design studio, course duration, requirements and effects are compared and discussed.]]>
<![CDATA[Soczysta majówka w Hiszpanii]]> Wed, 27 May 2020 08:06:28 +0200 Donnersberg, Anna
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<![CDATA[Rheology and mechanical properties of fly ash-based geopolymer mortars with ground granulated blast furnace slag addition]]> Tue, 26 May 2020 14:22:40 +0200 Sitarz, Mateusz; Urban, Maciej; Hager, Izabela
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Abstrakt: Geopolymers are less energy-demanding alternatives to Portland cement binders. The subject of geopolymer rheology has not yet been fully explored, and the available literature is limited to a narrow range of material compositions. This paper presents the rheological and mechanical response of fly-ash based geopolymer mortars. Investigations were made of the effect of different levels of ground granulated blast furnace slag (GGBFS) addition levels on the rheological properties of fresh geopolymers as well as their mechanical performances at 2, 14 and 28 days. The aim of the study was to obtain flow curves and to establish the correlation between shear stress and shear rate. The results have shown that geopolymer mortar is a pseudoplastic liquid presenting shear thinning behavior, moreover, with the increase of GGBFS content, higher material strengths were obtained and the total porosity was reduced.]]>
<![CDATA[Extension of the Thomas algorithm to a class of algebraic linear equation systems involving quasi-block-tridiagonal matrices with isolated block-pentadiagonal rows, assuming variable block dimensions]]> Mon, 25 May 2020 10:39:40 +0200 Bieniasz, L. K.
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Abstrakt: The popular sequential Thomas algorithm for the numerical solution of tridiagonal linear algebraic equation systems is extended on a class of quasi-block-tridiagonal equation systems arising from finite-difference discretisations of boundary value and initial boundary value problems of reaction-migration-advection-diffusion type in one space dimension, occurring in electrochemistry. The extension allows for a simultaneous consideration of: (a) multiple space intervals with common boundaries; (b) additional algebraic or differential-algebraic equations coupled with mixed boundary conditions, that may express e.g. adsorption at the boundaries; (c) three-point finite-difference approximations to the gradients of the solutions of the initial/boundary value problems at the boundaries; (d) periodic or non-periodic boundary conditions at the external boundaries. The resulting equation matrix may include nonzero off-diagonal corner blocks associated with periodic boundary conditions, may be locally block-pentadiagonal at a number of isolated rows corresponding to internal spatial boundaries, and its blocks may have variable dimensions. Testing calculations are performed.]]>
<![CDATA[Erratum: Extension of the Thomas algorithm to a class of algebraic linear equation systems involving quasi-block-tridiagonal matrices with isolated block-pentadiagonal rows, assuming variable block dimensions [Computing 67(4): 269–285 (2001)]]]> Mon, 25 May 2020 10:22:29 +0200 Bieniasz, L. K.
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<![CDATA[Inter-observer and intra-observer reliability in the radiographic measurements of paediatric forefoot alignment]]> Mon, 25 May 2020 09:41:36 +0200 Jasiewicz, Barbara; Pietraszek, Jacek; Duda, Sławomir; Pietrzak, Szymon; Pruszczyński, Błażej; Parol, Tomasz; Potaczek, Tomasz; Gądek-Moszczak, Aneta
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Abstrakt: Foot bones in children have more rounded shapes in radiograms than adults. Thus, the goal of this work was assessing inter- and intra-observer reliability in paediatric forefoot angle measurements. Six forefoot angles in 34 AP standing paediatric foot radiographs were measured by 5 researchers. A classic statistical analysis with use of IBM SPSS Statistics 25 was performed and a new method with two-way analysis of variance was applied. Results of statistical analysis revealed the properties of a subjective assessment related to specific angles. Kilmartin’s angle, calcaneus-fifth metatarsal angle and first ray angle are the most reliable; metatarsus adductus angle should be used with great caution in pediatric population. Engel’s angle is the most difficult for measuring and measurement error is the highest. The power of paediatric forefoot measurements is various. Several angles are reliable, while Engle’s angle is the most doubtful.]]>
<![CDATA[Use of dynamically adaptive grid techniques for the solution of electrochemical kinetic equations: Part 7. Testing of the finite-difference patch-adaptive strategy on example kinetic models with moving reaction fronts, in one-dimensional space geometry]]> Mon, 25 May 2020 09:15:07 +0200 Bieniasz, L. K.; Bureau, C.
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Abstrakt: The patch-adaptive strategy described in Part 5 proves to provide correct, fairly efficient, and nearly automatic solutions to three representative example electrochemical kinetic models in one-dimensional space geometry, that exhibit difficult-to-resolve moving reaction fronts in the electrolyte, away from the electrode. The models describe: double potential step experiments for a simple mechanism of electrochemically generated luminescence, linear potential sweep voltammetry for an EE-DISP mechanism with Nernstian charge transfers and a reversible homogeneous disproportionation reaction, and linear potential sweep voltammetry for an RRC-initiated electropolymerization reaction scheme. The strategy dynamically creates spatio-temporal grids that adaptively concentrate in the regions of the reaction fronts, without any a priori knowledge about their location. Numerical difficulties, such as electric current oscillations observed with the previously described adaptive moving grid technique in the case of moving reaction fronts, do not occur in the present strategy. However, further work is needed to improve the performance of the strategy in the cases of reaction fronts associated with fast and irreversible second-order homogeneous reactions, for which the computational costs are too large. Improvements are also desirable in the case of the simulation of a rapidly moving reaction front occurring in the electropolymerization model, for which the strategy tends to provide incorrect front positions.]]>
<![CDATA[Thermal calculations of plate-fin-and-tube heat exchangers with different heat transfer coefficients on each tube row]]> Mon, 25 May 2020 08:49:19 +0200 Taler, Dawid; Taler, Jan; Trojan, Marcin
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Abstrakt: In finned tube heat exchangers, the first rows of tubes are most effective when air velocity in front of the exchanger is less than about 3.5 m/s. The heat transfer coefficient (HTC) decreases with each subsequent row and stabilizes only from the fifth row onwards. The paper examines a two-pass double row plate-fin and tube heat exchanger (PFTHE) made of circular or oval pipes. A method for determining the air side Nusselt number on individual pipe row was developed, using the results of CFD (Computational Fluid Dynamics) modelling of the heat exchanger. Also, a heat transfer correlation was found for the mean HTC for the whole PFTHE using CFD modelling. The correlations based on the results of CFD modelling match very well the empirical correlations based on experimental tests of two car radiators. The analysis shows that the first rows of pipes, it is possible to reduce investment expenditures at the same thermal output significantly. Heating systems with PFTHE air heaters with fewer rows of pipes are characterized by lower fuel consumption due to their higher efficiency. The investment costs for automotive radiators can also be reduced. The introduction of PFTHE heat exchangers with fewer pipe rows has a positive impact on the environment. Both material expenditures on the construction of PFTHE, energy consumption by the air fan, and fuel consumption for heating purposes are reduced.]]>
<![CDATA[IT-based control and assessment of partnering relations in construction projects]]> Mon, 25 May 2020 08:45:54 +0200 Szewczyk, Bartłomiej; Radziszewska-Zielina, Elżbieta
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Abstrakt: This paper presents a digital system for controlling and assessing partnering relations during the carrying out of construction projects, called “B-rel”. The system provides recommendations that can improve specific partnering relations parameters. Its novelty is based on considering how the improvement of individual partnering relations parameters carries over to the time, cost, quality and safety of carrying out a project. The study shows that developing partnering relations in construction projects has the greatest carryover to benefits concerning their time and cost. The system features a learning module and an explanatory module. Thus, B-rel is able to adapt to a specific project and present an inference path that leads to a given recommendation. It can also present saved parameter ratings using graphs. The system's operation has been tested on the example of an actual construction project, demonstrating that the system can successfully support partnering relations management.]]>
<![CDATA[The effect of molding conditions on the quality of geopolymer surfaces]]> Mon, 25 May 2020 08:11:45 +0200 Jaglarz, Janusz; Wyszyński, Dominik; Łach, Michał; Mikuła, Janusz; Duraj,Ryszard
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Abstrakt: The presented work describes the method of measuring surface topography with application of BRDF (bidirectional reflectance distribution function), ellipsometry and spectrophotometry. This non-contact method enables measurement and analysis of large area surfaces, such as plasters and facades. A standard method of topography analysis does not describe sufficiently all of the interesting features. The visual aspect of the surface evaluation is very important from the functional and utilitarian point of view. The proposed methods of surface analysis enable not only the quantitative evaluation but also indirectly the qualitative properties (visual aspects).]]>
<![CDATA[Corrigendum to: "Use of dynamically adaptive grid techniques for the solution of electrochemical kinetic equations. Part 7. Testing of the finite-difference patch-adaptive strategy on example kinetic models with moving reaction fronts, in one-dimensional space geometry" [J. Electroanal. Chem. 481 (2000) 152–167]]]> Fri, 22 May 2020 14:53:36 +0200 Bieniasz, L. K.; Bureau, C.
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<![CDATA[Evaluation of surface roughness and defect formation after the machining of sintered aluminum alloy AlSi10Mg]]> Fri, 22 May 2020 11:13:00 +0200 Struzikiewicz, Grzegorz; Sioma, Andrzej
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Abstrakt: This article presents selected issues related to the workpiece surface quality after machining by the laser sintering of AlSi10MG alloy powder. The surfaces of the workpiece were prepared and machined by longitudinal turning with tools made of sintered carbides. The occurrence of breaches on the machined material surface was found, which negatively influence the values of 3D surface roughness parameters. The occurring phenomena were analyzed and proposals for their explanation were made. Guidelines for the machining of workpieces achieved by the laser sintering of powders were developed. The lowest value of the 3D roughness parameters was obtained for f = 0.06 mm/rev, ap = 0.5–1.0 mm, and for the nose radius of cutting insert rε = 0.8 mm. The results of research on the effect of cutting parameters on the values of parameters describing the surface quality are presented. Topography measurements and 3D surface roughness parameters are presented, as well as the results of a microscopic 3D surface analysis. Taguchi’s method was used in the research methodology.]]>
<![CDATA[Linear voltammetric current functions for a pseudo-first-order EC catalytic reaction scheme with DO ≠ DR: Series expansion algorithm]]> Fri, 22 May 2020 10:42:42 +0200 Bieniasz, Lesław K.
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Abstrakt: Series expansions have been obtained for the linear voltammetric current functions for the case of a pseudo-first-order EC catalytic reaction scheme with a reversible or totally irreversible charge transfer reaction involving species of different diffusion coefficients DO, DR. Semi-infinite diffusion to stationary, planar electrodes was assumed. A theoretical discussion of the current function is presented for the case of the catalytic scheme involving a totally irreversible charge transfer reaction at DO ≠ DR. Methods which use the series expansion algorithms, allowing evaluation of the kinetic parameter of the chemical catalytic reaction and the ratio DO/DR from the experimental linear voltammetric data, are proposed.]]>
<![CDATA[Influence of diffusion coefficient ratio DO/DR on potential-step chronoamperometric and linear voltammetric current at stationary planar electrodes in the case of a pseudo-first-order EC catalytic reaction scheme]]> Fri, 22 May 2020 10:33:21 +0200 Bieniasz, L.
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Abstrakt: Equations for limiting potential-step chronoamperometric and linear voltammetric currents at stationary planar electrodes for the case DO ≠ DR have been derived for a pseudo-first-order EC catalytic reaction scheme with reversible electrochemical and irreversible chemical reactions. The limiting potential-step chronoamperometric and linear voltammetric current curves have been calculated for various values of the diffusion coefficient ratio DO/DR. The influence of the ratio DO/DR on the theoretical currents has been examined. Theoretical possibilities to deduce both the kinetic parameter of the homogeneous chemical catalytic reaction and the ratio DO/DR from the experimental limiting potential-step current-time curves or linear voltammetric current-potential curves have been discussed. A simple diagnostic criterion for linear voltammetry allowing evaluation of the chemical reaction rate constant and the ratio DO/DR, has been proposed.]]>
<![CDATA[Derivations of group rings]]> Fri, 22 May 2020 10:23:11 +0200 Artemovych, Orest D.; Bovdi, Victor A.; Salim, Mohamed A.
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Abstrakt: Let R[G] be the group ring of a group G over an associative ring R with unity such that all prime divisors of orders of elements of G are invertible in R. If R is finite and G is a Chernikov (torsion F C-) group, then each R-derivation of R[G] is inner. Similar results also are obtained for other classes of groups G and rings R.]]>
<![CDATA[Use of dynamically adaptive grid techniques for the solution of electrochemical kinetic equations: Part 6. Testing of the finite-difference patch-adaptive strategy on example models with solution difficulties at the electrodes, in one-dimensional space geometry]]> Thu, 21 May 2020 11:22:22 +0200 Bieniasz, L. K.
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Abstrakt: The patch-adaptive strategy described in Part 5 proves to provide correct, fairly efficient, and nearly automatic solutions to six representative example electrochemical kinetic models in one-dimensional space geometry, that exhibit difficult-to-resolve local spatial and temporal solution structures at the electrodes. The models describe: the square-wave controlled potential transient for an uncomplicated heterogeneous charge transfer reaction, the potential step method and linear potential sweep voltammetry for the standard catalytic reaction mechanism with a pseudo-first-order homogeneous reaction, linear potential sweep voltammetry for an EC reaction mechanism involving a follow-up homogeneous dimerisation, steady-state voltammetry at a rotating disc electrode, and steady-state voltammetry at a spherical microelectrode. These examples are characterised by extremely thin reaction layers and other instances of local spatial regions of considerable variations of the solution, including transient effects caused by temporal discontinuities of boundary conditions. The strategy creates dynamically spatio-temporal grids well adapted to such solution structures, without any a priori knowledge about their location. The accuracy of the numerical solutions proves well controlled by means of error tolerance parameters. Numerical difficulties observed with the previously described adaptive moving grid technique do not occur in the present strategy. However, further work is needed to improve the performance of the strategy in the cases of thin reaction layers associated with fast second-order homogeneous reactions, and boundary layers associated with hydrodynamic electroanalytical methods, for which the computational effort appears too large.]]>
<![CDATA[Corrigendum to: "Use of dynamically adaptive grid techniques for the solution of electrochemical kinetic equations. Part 6. Testing of the finite-difference patch-adaptive strategy on example models with solution difficulties at the electrodes, in one-dimensional space geometry" [J. Electroanal. Chem. 481 (2000) 134–151]]]> Thu, 21 May 2020 11:06:58 +0200 Bieniasz, L. K.
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<![CDATA[The morphology and mechanical properties of ESD Coatings before and after laser beam machining]]> Thu, 21 May 2020 10:05:59 +0200 Radek, Norbert; Pietraszek, Jacek; Gądek-Moszczak, Aneta; Orman, Łukasz J.; Szczotok, Agnieszka
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Abstrakt: Electro-spark deposition (ESD) and laser beam machining (LBM) are the technologies using the concentrated energy flux. This paper deals with the issue of the impact of laser modification on the morphology and mechanical properties of carbide/copper coatings produced by electro-spark treatment. The coatings were applied to C45 carbon steel samples using the EIL-8A device. The following three types of electrodes made using the powder metallurgy (PM) hot pressing technique, from copper and tungsten carbide powders of di erent percentage compositions, were used for the coatings: 25% WC and 75% Cu; 50% WC and 50% Cu; and 75% WC and 25% Cu. Laser modification of the surface layers was performed with an Nd:YAG laser. The research focused on the analysis of the morphology of coatings applied by electro-spark technology before and after laser processing. The analysis of the morphology of electro-spark coatings revealed that the coatings had microcracks and pores. The laser beam machining of ESD coatings led to the homogenization of chemical composition, fragmentation of the structure, and elimination of microcracks. In addition, measurements of porosity, microhardness, adhesion, and analysis of XRD phase composition of the electro-spark coatings were performed. Laser processing proved to have a positive e ect on improving the adhesion of coatings and reducing their porosity. This paper also presents a simulation model of heat transfer processes for the case of laser radiation impact on a WC-Cu coating. The developed numerical model, describing the influence of laser treatment on the distribution of temperature fields in the heated material (at a given depth) is of significant importance in the development of treatment technologies. Laser-modified ESD coatings perform anti-wear and protective functions, which enable their potential application in means of transport such as rolling stock.]]>
<![CDATA[Izobaryczna metoda stacjonarna wyznaczania współczynników dyfuzji w materiałach porowatych]]> Wed, 20 May 2020 11:25:52 +0200 Boroń, Dominika
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Abstrakt: Przedstawiono podstawy teoretyczne i algorytm postępowania służący do doświadczalnego wyznaczania współczynników dyfuzji w makroporowatych ciałach stałych. Uwzględniono jednoczesną dyfuzję molekularną i dyfuzję Knudsena. Zaproponowano i przetestowano metodę estymacji skorelowanych współczynników dyfuzji. Ten sposób można zastosować do pomiarów prowadzonych w warunkach ustalonych pod ciśnieniem atmosferycznym, z użyciem dwuskładnikowych roztworów gazowych o zróżnicowanym składzie. Zilustrowano go na przykładach dwóch układów dyfuzyjnych różniących się stosunkiem mas cząsteczkowych składników: {H2, N2} oraz {CO2, H2}.]]>
<![CDATA[Use of dynamically adaptive grid techniques for the solution of electrochemical kinetic equations: Part 5. A finite-difference, adaptive space/time grid strategy based on a patch-type local uniform spatial grid refinement, for kinetic models in one-dimensional space geometry]]> Wed, 20 May 2020 10:57:37 +0200 Bieniasz, L. K.
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Abstrakt: Local, difficult-to-solve spatio-temporal structures such as extremely thin reaction layers at the electrodes, thin moving reaction fronts, fast transient variations, isolated temporal discontinuities in boundary conditions, edge effects, etc. are characteristic of the initial boundary value and boundary value problems occurring in electrochemical kinetic modelling. Further progress in the simulation methodology is hindered by the lack of automatic solution techniques for such problems. Based on a critical consideration of various adaptive grid strategies for partial differential equations reported in the scientific literature, a new finite-difference adaptive grid strategy has been formulated, that is especially designed for electrochemical kinetic simulations, and is currently limited to models in one-dimensional space geometry. The intention is to enable an automatic solution of the governing partial/ordinary differential equations to a prescribed accuracy, without any a priori knowledge about the spatio-temporal location of the emerging solution structures. In view of the importance of the solution (concentration) gradients for the electrochemical theory, simultaneous control of the spatial errors of the solutions and their spatial gradients is included in the strategy. Spatial grid adaptation is based on a local uniform grid refinement, using overlapping grid patches. Temporal step selection uses a recent control theoretic algorithm, combined with a simple method of detecting temporal discontinuities of the boundary conditions. A third-order accurate, implicit and L-stable Rosenbrock time-stepping scheme ROWDA3 is used to enable efficient and non-oscillatory temporal integration in the time intervals where a regular solution occurs. A second-order accurate Lawson–Morris–Gourlay extrapolation scheme is used to enable a reliable time-stepping at temporal discontinuities.]]>
<![CDATA[Corrigendum to: "Use of dynamically adaptive grid techniques for the solution of electrochemical kinetic equations. Part 5. A finite-difference, adaptive space/time grid strategy based on a patch-type local uniform spatial grid refinement, for kinetic models in one-dimensional space geometry" [J. Electroanal. Chem. 481 (2000) 115–133]]]> Wed, 20 May 2020 10:41:11 +0200 Bieniasz, L. K.
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<![CDATA[Photochemical study of a new bimolecular photoinitiating system for vat photopolymerization 3D printing techniques under visible light]]> Wed, 20 May 2020 10:08:47 +0200 Fiedor, Paweł; Pilch, Maciej; Szymaszek, Patryk; Chachaj-Brekiesz, Anna; Galek, Mariusz; Ortyl, Joanna
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Abstrakt: In this work, we presented a new bimolecular photoinitiating system based on 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives as visible photosensitizers of diphenyliodonium salt. Real-time FTIR and photo-DSC photopolymerization experiments with a cycloaliphatic epoxide and vinyl monomers showed surprisingly good reactivity of the bimolecular photoinitiating systems under UV-A, as well as under visible light sources. Steady-state photolysis, fluorescence experiments, theoretical calculations of molecular orbitals, and electrochemical analysis demonstrated photo-redox behavior as well as the ability to form initiating species via photo-reduction or photo-oxidation pathways, respectively. Therefore, the 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives were also investigated as a type II free-radical photoinitiator with amine. It was confirmed that the 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives, in combination with different types of additives, e.g., amine as a co-initiator or the presence of onium salt, can act as bimolecular photoinitiating systems for cationic, free-radical, and thiol-ene photopolymerization processes by hydrogen abstraction and/or electron transfer reactions stimulated by either near-UV or visible light irradiation. Finally, the 2-amino-4,6-diphenylpyridine-3-carbonitrile derivatives were selected for 3D printing rapid prototyping experiments. Test objects were successfully printed using purely cationic photosensitive resin, created on a 3D printer with a visible LED light source.]]>
<![CDATA[Structural study on hypochlorous acid-mediated chlorination of betanin and its decarboxylated derivatives from an anti-inflammatory Beta vulgaris L. extract]]> Wed, 20 May 2020 10:05:16 +0200 Kumorkiewicz-Jamro, Agnieszka; Starzak, Karolina; Sutor, Katarzyna; Nemzer, Boris; Pietrzkowski, Zbigniew; Popenda, Łukasz; Wybraniec, Sławomir
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Abstrakt: Hypochlorous acid (HOCl) produced by neutrophils is a part of the natural innate immune response system in the human body, but excessive levels of HOCl can ultimately be detrimental to health. Recent reports suggest that betacyanin plant pigments can act as potent scavengers of inflammatory factors and are notably effective against HOCl. In this contribution, chlorination mechanism and position of the electrophilic substitution in betacyanins was studied by high‐resolution mass spectrometry and further structural analyses by NMR techniques, which completed the identification of the chlorinated betacyanins. For the study on the influence of the position of decarboxylation on the chlorination mechanism, a comparison of the chlorination position between betanin as well as 17‐, and 2,17‐decarboxylated betanins was performed. The structural study confirmed that the chlorination position in betanin occurs within the dihydropyridinic moiety at carbon C‐18. Therefore, out of the aqueous free chlorine equilibrium species: HOCl, OCl−, Cl2, and Cl2O, the most potent chlorinating agents are HOCl and Cl2O postulated previously and the attack of the Cl⁺ ion on the carbon C‐18 with a cyclic intermediate version is considered.]]>
<![CDATA[Effects generated by the magnetic core anisotropy of an induction motor]]> Wed, 20 May 2020 10:03:18 +0200 Warzecha, Adam; Mazgaj, Witold
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Abstrakt: A theoretical analysis enables effects generated by the magnetic core anisotropy of an induction motor to be determined qualitatively. Relationships formulated between currents and magnetic flux linkages that are associated with three-phase stator windings enable the qualitative determination of spectra of currents or voltages of a typical induction motor. These relationships account for nonlinear and anisotropic magnetization characteristics of the motor core, both during idle running and motor starting. Based on these relationships, components of the amplitude Fourier spectra of symmetrical components of currents or voltages, which are useful in the diagnostics of stator or rotor core anisotropy, were selected. Field calculations were performed for the core of a two-pole 5.5 kW motor supplied by three-phase sinusoidal currents. The components of the induced voltage Fourier spectra in both the idle running and short-circuit state were similar to analogous components predicted based on theoretical studies. The components occurring in the spectra, which were obtained based on field calculations, were distinguished in the measured spectra of the symmetrical components of the phase currents. These components were applied to estimate representative current signal levels in the diagnostics of motor core anisotropy. Relative values of these signals did not exceed 60 dB; however, they were significant for assessing the internal asymmetry level of the motor stator or rotor core. The results of laboratory measurements confirmed the results of the theoretical analysis.]]>
<![CDATA[Water-soluble photoinitiators in biomedical applications]]> Wed, 20 May 2020 09:56:25 +0200 Tomal, Wiktoria; Ortyl, Joanna
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Abstrakt: Light-initiated polymerization processes are currently an important tool in various industrial fields. The advancement of technology has resulted in the use of photopolymerization in various biomedical applications, such as the production of 3D hydrogel structures, the encapsulation of cells, and in drug delivery systems. The use of photopolymerization processes requires an appropriate initiating system that, in biomedical applications, must meet additional criteria such as high water solubility, non-toxicity to cells, and compatibility with visible low-power light sources. This article is a literature review on those compounds that act as photoinitiators of photopolymerization processes in biomedical applications. The division of initiators according to the method of photoinitiation was described and the related mechanisms were discussed. Examples from each group of photoinitiators are presented, and their benefits, limitations, and applications are outlined.]]>
<![CDATA[Trends in sunshine duration in Poland (1971–2018)]]> Wed, 20 May 2020 09:09:00 +0200 Bartoszek, Krzysztof; Matuszko, Dorota; Węglarczyk, Stanisław
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Abstrakt: This study aims to characterize temporal and spatial trends of sunshine duration in Poland based on data from the years 1971 – 2018 and to make an attempt to explain their causes. Daily sunshine duration came from 31 Polish meteorological stations. Data from 10 stations came only from a traditional Campbell – Stokes heliograph, while in the other 21 synoptic stations Campbell – Stokes heliograph was replaced with an automatic sensor in 2014 and since then only such data are available. The smallest sunshine duration occurs in December (average areal total — 39.7 hr), and the highest in July (average areal total — 230.1 hr). The spatial distribution of sunshine duration in Poland shows great diversity associated with different day lengths depending on latitude. In the cool part of the year (November, December, January, and February) the isolines of totals of sunshine duration run from the highest values in the south to the lowest in the north of the country, while in the months of the warm part of the year (March to September) the system is reversed. The multi-annual trends in sunshine duration in Poland are similar to the changes taking place in other parts of the world. The years 1971 – 1980 mark the end of “ global dimming, ” which was manifested in very low values of actual and relative sunshine duration. “ Global brightening ” confirms a statistically significant growing trend in sunshine duration at all the analysed meteorological stations in Poland from April to September. There is a strong statistically significant relationship between the areal totals of sunshine duration and the type of pressure system, average monthly cloud cover, and atmospheric optical depth.]]>
<![CDATA[Kinetics of anodic processes in molten carbonate fuel cell. Part I. Voltammetry of hydrogen on Pt electrodes in molten carbonates+solid matrix electrolytes]]> Tue, 19 May 2020 12:33:21 +0200 Suski, Leszek; Bieniasz, Lesław; Gil, Aleksander; Wyrwa, Jan
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Abstrakt: Wyznaczono krzywe woltametryczne dla procesów katodowych i anodowych z udziałem wodoru, zachodzących na elektrodach Pt w elektrolitach: stopione (Li2CO3+Na2CO3)+stałe (MgO lub LiAlO2), w temperaturze 850 K. Kształty pików anodowego utleniania wodoru w elektrolitach z matrycami MgO i LiAlO2 różnią się między sobą. Wyniki sugerują katalityczny charakter zarówno katodowych jak anodowych reakcji wodoru w stopionych węglanach.]]>
<![CDATA[Photovoltaic cells with various azo dyes as components of the active layer]]> Tue, 19 May 2020 09:58:08 +0200 Derkowska-Zielinska, Beata; Gondek, Ewa; Pokladko-Kowar, Monika; Kaczmarek-Kedziera, Anna; Kysil, Andrii; Lakshminarayana, Gandham; Krupka, Oksana
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Abstrakt: The photovoltaic response of six cells with an active layer of heterocyclic azo dyes is presented for the first time. The active azo layers differed in the type of substituent (i.e. electron-donating: CH3, OCH3 and electron withdrawing: Br). We showed that by changing the substituent in the heterocyclic azo dye we change the power efficiency of the device. It should be mentioned that all presented data showed high potential of heterocyclic azo dyes for effective photovoltaic output. The studied heterocyclic azo dyes have higher photovoltaic parameters than those obtained for photovoltaic cell with 4-Diethoxyphenylsilylazobenzene.]]>
<![CDATA[Analysis of heavy metals leaching from internal pipe cement coating into potable water]]> Tue, 19 May 2020 09:56:59 +0200 Bielski, Andrzej; Zielina, Michał; Młyńska, Anna
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Abstrakt: This paper presents a mathematical model of chromium and lead leaching from internal pipe cement coatings to drinking water soon after renovation. Among other things, the model takes into account the adsorption of heavy metals inside porous cement coatings and diffusive transport, not only in coating capillaries but also in a water phase inside the pipe. Such phenomena have been ignored in other mathematical models simulating the leaching of heavy metals from pipe cement coatings. The proposed mathematical model was experimentally verified and high correlation between the results was observed. It has been proven that sorption inside the cement coating was responsible for the visible decrease of leaching in time, and that diffusive transport in the liquid phase inside the pipe influenced leaching speed. The experimental and numerical tests showed an initial sudden and significant increase to more than 10 μg/dm3, followed by a gradual decrease of chromium and lead leaching, reaching equilibrium concentrations close to 2.0 μg/dm3 after about 20 days. Enlargement of hydraulic pressure inside the pipe did not affect the initial increase of heavy metal concentrations in the water phase, but accelerated their decrease. The use of a twice larger pipe diameter led to an almost twofold reduction of initial peak chromium concentration inside the pipe.]]>
<![CDATA[Electric field stress determination tool for MV insulation system models]]> Tue, 19 May 2020 09:55:20 +0200 Szafraniak, Bartlomiej; Fusnik, Lukasz; Bonk, Michal; Smugala, Dariusz
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Abstrakt: The evolution of teaching methods concerned with electrical engineering enables the development of new measurement stands or the improvement of existing educational methods. The advancement in engineering equipment is affecting the formation of new methodologies in teaching. Nevertheless, new educational techniques should be implemented by taking into account understanding of a physical basis of studied phenomena. This goal may be achieved via a combination of practical exercises conducted on testing stands, during evaluation, by means of modern computerized tools. In this paper, we described the combination of a numeric study of electric field (EF) distribution and an improved analog method analysis performed on an educational set‐up. For an effective understanding of technical problems of high‐voltage (HV) and medium‐voltage technology, the presented educational tool combines an experimental method of EF equipotential line mapping and EF strength determination with an improved analog method of EF strength inside the HV insulation system, which is determined by means of differential equation calculation implemented on the developed software. For fast verification of the results, computer simulations were applied. It allows for presenting the strong and weak points of both used methods. Analyzed models reproducing real devices were built on different scales; thus, achieved results reflect the real values and may be used for study help during seminars.]]>
<![CDATA[The significance of halogen bonding in ligand–receptor interactions: the lesson learned from molecular dynamic simulations of the D4 receptor]]> Tue, 19 May 2020 09:44:37 +0200 Kurczab, Rafał; Kucwaj-Brysz, Katarzyna; Śliwa, Paweł
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Abstrakt: Recently, a computational approach combining a structure–activity relationship library containing pairs of halogenated ligands and their corresponding unsubstituted ligands (called XSAR) with QM-based molecular docking and binding free energy calculations was developed and used to search for amino acids frequently targeted by halogen bonding, also known as XB hot spots. However, the analysis of ligand–receptor complexes with halogen bonds obtained by molecular docking provides a limited ability to study the role and significance of halogen bonding in biological systems. Thus, a set of molecular dynamics simulations for the dopamine D4 receptor, recently crystallized with the antipsychotic drug nemonapride (5WIU), and the five XSAR sets were performed to verify the identified hot spots for halogen bonding, in other words, primary (V5x40), and secondary (S5x43, S5x461 and H6x55). The simulations confirmed the key role of halogen bonding with V5x40 and H6x55 and supported S5x43 and S5x461. The results showed that steric restrictions and the topology of the molecular core have a crucial impact on the stabilization of the ligand–receptor complex by halogen bonding.]]>
<![CDATA[Application of Fragment Molecular Orbital Method to investigate dopamine receptors]]> Tue, 19 May 2020 09:40:18 +0200 Preikša, Jokūbas; Śliwa, Paweł
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Abstrakt: GPCRs are a vast family of seven-domain transmembrane proteins. This family includes dopamine receptors (D1, D2, D3, D4, and D5), which mediate the variety of dopamine-controlled physiological functions in the brain and periphery. Ligands of dopamine receptors are used for managing several neuropsychiatric disorders, including bipolar disorder, schizophrenia, anxiety, and Parkinson’s disease. Recent studies have revealed that dopamine receptors could be part of multiple signaling cascades, rather than of a single signaling pathway. For these targets, a variety of experimental and computational drug design techniques are utilized. In this work, dopamine receptors D2, D3, and D4 were investigated using molecular dynamic method as well as computational ab initio Fragment Molecular Orbital method (FMO), which can reveal atomistic details about ligand binding. The results provided useful insights into the significances of amino acid residues in ligand binding sites. Moreover, similarities and differences between active-sites of three studied types of receptors were examined.]]>
<![CDATA[Assessment of thermal comfort in the intelligent buildings in view of providing high quality indoor environment]]> Tue, 19 May 2020 09:35:06 +0200 Majewski, Grzegorz; Orman, Łukasz J.; Telejko, Marek; Radek, Norbert; Pietraszek, Jacek; Dudek, Agata
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Abstrakt: The paper analyses the indoor environment in two modern intelligent buildings located in Poland. Measurements of air and globe temperatures, relative humidity and carbon dioxide concentration in 117 rooms carried out in the space of 1.5 years were presented. Thermal comfort of the occupants has been investigated using a questionnaire survey. Based on 1369 questionnaires, thermal sensation, acceptability and preference votes were analysed in view of their interdependency as well as their dependency on operative temperature, which proved to be very strong. It has been found that the respondents did not completely rate thermal comfort and indoor environment quality as very high, although the overwhelming sensations were positive. Apart from the operation of heating, ventilation and air conditioning (HVAC) systems, this might have also been the cause of individual human factors, such as body mass index, as tested in the study, or the finding that people were generally in favour of a warmer environment. Moreover, thermal environment proved to be the most important element for ensuring the well-being of the occupants.]]>
<![CDATA[Vibroacoustic activity of modern hoist machines in passenger lift instalations]]> Tue, 19 May 2020 08:40:04 +0200 Dziechciowski, Zygmunt; Czerwiński, Andrzej; Łatas, Waldemar
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Abstrakt: The study investigates the sound levels registered inside the apartments in residential buildings resulting from the operation of the passenger lift installations. Modern multi-family residential buildings are typically equipped with machine room-less (MRL) passenger lift installations where the drive units are mounted directly on the shaft walls. Noise and vibration of the passenger lift operation has now become a major concern. Errors in engineering designs can lead to elevated noise levels in residences, particularly those adjacent to the lift equipment. Subsequently, this may result in exceeding the permissible values of noise level, also vibrations in the apartments. Exceeding the permissible values of vibration and noise level on the one hand is a problem for users of residential premises, and on the other hand, it has an economic dimension, because the improvement of irregularities is often very expensive and financially burdens the developer. This paper summarizes the results of studies highlighting the problem of elevated sound levels in residential areas adjacent to the shaft. The measurements of vibrations and noise in the apartment, as well as in the elevator shaft, showed that the vibroacoustic (V-A) signal is transmitted from the device to the flat. Spectral analysis and signal variability in the time domain were used. As part of corrective actions, mitigation measures and vibration isolation strategies have been proposed, however, not all proposals were feasible. Measurement results obtained prior to and following the vibroacoustic adaptation are compared in the context of noise and vibration control.]]>
<![CDATA[Reliable reduction potentials of diaryliodonium cations and aryl radicals in acetonitrile from high-level ab initio computations]]> Tue, 19 May 2020 08:07:13 +0200 Romańczyk, Piotr P.; Kurek, Stefan S.
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Abstrakt: The experimental values of the standard reduction potentials of diaryliodonium cations (Ar2I+) and aryl radicals (Ar) are generally not deemed reliable owing to the irreversibility of electrode processes, often aggravated by blocking the electrode by the grafted layer. They are, however, required for the prediction of suitability of photoinitiators and the course of arylation reactions or aryl radical surface modifications. Here, we present accurate E° values of reduction of symmetrical and unsymmetrical Ar2I+, and of Ar in MeCN, obtained from calculations based on the gas-phase redox energetics from the high-level explicitly correlated coupled-cluster method (CCSD(T)-F12) combined with the SMD solvation free energies. Plausible paths of C-I bond cleavage in unsymmetrical Ar2I+ cations were also predicted from reference values of the C-I bond dissociation energies (BDEs) in Ar2I+. The computed reduction potentials were compared with available experimental data and with results from other quantum chemical methods including other implicit solvation models. A perfect linear correlation with Hammett's constants was found for the computed potentials of Ar2I+ reduction. This correlation equation may be used for rapid estimation of reduction potentials of other Ar2I+ cations, but also for the prediction of the fate of other processes, in which diaryliodonium cations take part, like aryl exchange reactions or the ability to initiate photopolymerisation.]]>
<![CDATA[Zastosowanie zaawansowanej metody oceny odporności ogniowej w budownictwie przemysłowym]]> Tue, 19 May 2020 08:06:36 +0200 Woźniczka, Piotr
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Abstrakt: W artykule przedstawiono przykład opracowanej oceny odporności ogniowej obiektu przemysłowego. Dla rozpatrywanej hali maszynowni o konstrukcji stalowej zaprezentowano wyniki symulacji rozwoju pożaru oraz odpowiedzi mechanicznej konstrukcji. Obliczenia przeprowadzono za pomocą zaawansowanych programów komputerowych. Omówiono wpływ takich czynników, jak nierównomierne ogrzewanie oraz sposób modelowania konstrukcji na szacowaną odporność ogniową. Wskazano także wartości temperatury krytycznej oraz prognozowane modele zniszczenia. Wykazano, że omawiana metoda może być z powodzeniem stosowana w odniesieniu do rozpatrywanej kategorii obiektów.]]>
<![CDATA[Kinetics of anodic processes in molten carbonate fuel cell. Part II. Equations for non-stationary diffusion controlled second order electrochemical process: Red+A⇌Ox1+Ox2+ne]]> Mon, 18 May 2020 10:26:20 +0200 Bieniasz, Lesław; Suski, Leszek
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Abstrakt: Przedstawiono formalizm kinetyczny dla kontrolowanej dyfuzyjnie reakcji elektrochemicznej drugiego rzędu: Red+A⇌Ox1+Ox2+ne w warunkach dyfuzji półnieskończonej, liniowej. Otrzymano rozwiązania dla impulsów potencjostatycznych, amperostatycznych i dla woltametrii liniowej.]]>
<![CDATA[Wavelet-based discrimination of isolated singularities masquerading as multifractals in detrended fluctuation analyses]]> Mon, 18 May 2020 08:34:23 +0200 Oświęcimka, Paweł; Drożdż, Stanisław; Frasca, Mattia; Gębarowski, Robert; Yoshimura, Natsue; Zunino, Luciano; Minati, Ludovico
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Abstrakt: The robustness of two widespread multifractal analysis methods, one based on detrended fluctuation analysis and one on wavelet leaders, is discussed in the context of time-series containing non-uniform structures with only isolated singularities. Signals generated by simulated and experimentally-realized chaos generators, together with synthetic data addressing particular aspects, are taken into consideration. The results reveal essential limitations affecting the ability of both methods to correctly infer the non-multifractal nature of signals devoid of a cascade-like hierarchy of singularities. Namely, signals harboring only isolated singularities are found to artefactually give rise to broad multifractal spectra, resembling those expected in the presence of a well-developed underlying multifractal structure. Hence, there is a real risk of incorrectly inferring multifractality due to isolated singularities. The careful consideration of local scaling properties and the distribution of Hölder exponent obtained, for example, through wavelet analysis, is indispensable for rigorously assessing the presence or absence of multifractality.]]>
<![CDATA[Grape cane extracts as multifunctional rejuvenating cosmetic ingredient: evaluation of sirtuin activity, tyrosinase inhibition and bioavailability potential]]> Mon, 18 May 2020 08:32:47 +0200 Malinowska, Magdalena Anna; Billet, Kévin; Drouet, Samantha; Munsch, Thibaut; Unlubayir, Marianne; Tungmunnithum, Duangjai; Giglioli-Guivarc’h, Nathalie; Hano, Christophe; Lanoue, Arnaud
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Abstrakt: Grape canes are waste biomass of viticulture containing bioactive polyphenols valuable in cosmetics. Whereas several studies reported the cosmetic activities of E-resveratrol, only few described the potential of E-ε-viniferin, the second major constituent of grape cane extracts (GCE), and none of them investigated GCE as a natural blend of polyphenols for cosmetic applications. In this study, we considered the potential of GCE from polyphenol-rich grape varieties as multifunctional cosmetic ingredients. HPLC analysis was performed to quantify major polyphenols in GCE i.e., catechin, epicatechin, E-resveratrol, E-piceatannol, ampelopsin A, E-ε-viniferin, hopeaphenol, isohopeaphenol, E-miyabenol C and E-vitisin B from selected cultivars. Skin whitening potential through tyrosinase inhibition assay and the activation capacity of cell longevity protein (SIRT1) of GCE were compared to pure E-resveratrol and E-ε-viniferin. Drug-likeness of GCE polyphenols were calculated, allowing the prediction of skin permeability and bioavailability. Finally, the present data enabled the consideration of GCE frompolyphenol-rich varieties asmultifunctional cosmetic ingredients in accordance with green chemistry practices.]]>
<![CDATA[Anti-hypochlorite, antioxidant, and catalytic activity of three polyphenol-rich super-foods investigated with the use of coumarin-based sensors]]> Mon, 18 May 2020 08:26:36 +0200 Starzak, Karolina; Świergosz, Tomasz; Matwijczuk, Arkadiusz; Creaven, Bernadette; Podleśny, Janusz; Karcz, Dariusz
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Abstrakt: The anti-hypochlorite activity of açaí (Euterpe oleracea Mart.), goji (Lycium barbarum L.) and schisandra (Schisandra chinensis) fruit extracts were assessed by determining the reactive chlorine species (RCS)-scavenging ability of these three “super-food” berries. In addition, the aqueous extracts obtained were employed as both the media and the catalyst in a green chemistry approach to the synthesis of a coumarin-based fluorescence turn-off sensor, which was then used for anti-hypochlorite activity testing. The aqueous extracts were also assessed for total phenolic content (TPC), using the Folin–Ciocalteu method, and the antioxidant activity using the ABTS+• assay. Moreover, the main water-soluble polyphenolic constituents of the extracts were identified by the HPLC-PDA-ESI-MS technique. Among the extracts tested, açaí demonstrated the highest anti-hypochlorite and antioxidant activities, while the highest TPC value was found for the goji extract. All extracts demonstrated modest catalytic activity as Knoevenagel condensation catalysts.]]>
<![CDATA[Simulation of transmission quality classification in Pay&Require multi-agent managed network by means of Machine Learning techniques]]> Mon, 18 May 2020 08:24:05 +0200 Żelasko, Dariusz
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Abstrakt: The assurance of transmission quality in computer networks appears to be an important issue, particularly from the perspective of rapid development of computer networks. In the previous research there were many attempts to implement various Quality of Service (QoS) techniques. Unfortunately, QoS parameters are not always assured - most frequently user pays certain amount of money for transmission parameters which will never be achieved. This paper presents simulation of a new concept, which is determining the transmission quality with the application of Machine Learning (ML). In general, transmission quality is described by means of four parameters, i.e. bandwidth, delay, jitter and packet loss ratio. Pay&Require was suggested as a solution, which allows the assurance of transmission quality in computer networks. This purpose was achieved by the use of multi-agent system which monitors the transmission parameters and checks if they meet the customer’s expectations. The transmission quality rating is a significant factor of Pay&Require. ML was applied in the process of simulation and for the research purpose the assessment system of the transmission quality was implemented. It enabled the test users to assess the quality of transmission. Data obtained in such way was then used in ML classification. Simulations were performed for nine classifiers: Nu-Support Vector Classifier (Nu-SVC), k-Nearest Neighbors algorithm (kNN), Random Forest Classifier, C-Support Vector Classifier (C-SVC), Radius Neighbors Classifier, Nearest Centroid Classifier, Extra Trees Classifier, Decision Tree Classifier and Linear Support Vector Classifier (Linear SVC). Simulations were also performed for two variants of Stacking Classifier. The first variant was a combination of Linear SVC, C-SVC, Nearest Centroid and kNN as estimators and Logistic Regression as the final estimator. In the second variant Random Forest, Extra Trees and kNN were used as estimators and Logistic Regression was applied as the final estimator. The best classification result with respect to the tested data, was achieved by variant 1 Stacking Classifier, it had 89% sensitivity (overall accuracy), with 11/100 incorrect classifications.]]>
<![CDATA[Zróżnicowanie skrajnych sum miesięcznych opadów atmosferycznych w polskich Karpatach Zachodnich i ich przedpolu]]> Mon, 18 May 2020 08:19:22 +0200 Cebulska, Marta; Twardosz, Robert
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Abstrakt: The paper focuses on the highest (Pmax) and lowest (Pmin) monthly precipitation totals over a period of one year from 18 sites in the Polish Western Carpathians and their foreland over the 138-year period from 1881 to 2018. It then uses the results to discuss the characteristics of the annual and long-term variability of such precipitation. On account of their varied relief, the Polish Carpathian Mountains display the greatest temporal and spatial variability of precipitation in Poland, ranging from complete absence to 500 mm per month. While Pmax demonstrates a more pronounced annual frequency pattern than Pmin, neither of them follows a statistically significant trend of variation. This is consistent with the absence of a trend as regards overall precipitation volumes in this area.]]>
<![CDATA[Contamination and environmental risk assessment of heavy metals in Sediments of Dobczyce reservoir and its tributaries – a literature review]]> Fri, 15 May 2020 11:27:43 +0200 Zemełka, Gabriela
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Abstrakt: Most transported particles released from a catchment area are deposited and accumulated in the sediment layers of water reservoirs. Along with mineral particles, contaminants originating from human activity and natural processes are added to such aquatic systems (e.g., heavy metals). This is an especially important issue when a reservoir is being used as a source of drinking water. The main aim of this study was the environmental risk assessment of the sediment in the Dobczyce Reservoir and two of its tributaries (the Raba River and Wolnica Stream) during the years of 2004–2007 and 2016, 2017. Substantial variations in heavy metals were found due to the land use and catchment management. The potential ecological risk showed an uneven distribution, and the overall ecological risk level ranged from low to moderate.]]>
<![CDATA[Application of 3-D Drucker–Prager material model to determine optimal operating parameters of centrifugal regeneration device]]> Thu, 14 May 2020 10:44:17 +0200 Łatas, Waldemar; Dańko, Rafał; Czapla, Przemysław
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Abstrakt: The process of metal casting indisposable sand molds is associated with the generation of large amounts of waste, mainly used molding and core sands, from which the molds and cores reproducing the external and internal shapes of the castings were made. It is estimated that about 600 kg of waste can come from the production of 1 ton of casting. The main component of the waste is quartz matrix, which after undergoing appropriate reclamation treatments can be recovered and reused in the production process. This article presents the theoretical foundations regarding the existing methods of quartz matrix recovery and an experimentally justified model of the regeneration process occurring in one of the varieties used in the practice of mechanical regenerators. The goal is to improve the quality of regenerated molding sand by means of liberating the sand grain’s surface from the layer of the used binding component. The elastic-plastic material model characterized by the Drucker–Prager yield criterion was used to describe the deformation of the sand layer during treatment performed in a centrifugal regenerator. Conclusions based on the results of numerical calculations, obtained with the use of the software adopting the material point method, enable us to find out how to control the device in a way that ensures a permanent reclamation effect which is independent of the working components that wear out over time.]]>
<![CDATA[Effect of FSW traverse speed on mechanical properties of copper plate joints]]> Thu, 14 May 2020 08:21:45 +0200 Machniewicz, Tomasz; Nosal, Przemysław; Korbel, Adam; Hebda, Marek
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Abstrakt: The paper describes the influence of the friction stir welding travel speed on the mechanical properties of the butt joints of copper plates. The results of static and fatigue tests of the base material (Cu-ETP R220) and welded specimens produced at various travel speeds were compared, considering a loading applied both parallel and perpendicularly to the rolling direction of the plates. The mechanical properties of the FSW joints were evaluated with respect to parameters of plates’ material in the delivery state and after recrystallisation annealing. The strength parameters of friction stir welding joints were compared with the data on tungsten inert gas welded joints of copper plates available in the literature. The results of microhardness tests and fractographic analysis of tested joints are also presented. Based on the above test results, it was shown that although in the whole range of considered traverse speeds (from 40 to 80 mm/min), comparable properties were obtained for FSW copper joints in terms of their visual and microstructural evaluation, their static and especially fatigue parameters were di erent, most apparent in the nine-fold greater observed average fatigue life. The fatigue tests turned out to be more sensitive criteria for evaluation of the FSW joints’ qualities.]]>