Comparison of usage of different neural structures to predict AAO layer thickness

Rad se bavi usporedbom uporabe triju osnovnih vrsta neuralnih jedinica u cilju stvaranja najprikladnijeg modela koji predviđa utvrđivanje konačne debljine sloja aluminijeva oksida koji nastaje na površini uz gustoću struje od 1 A∙dm−2. Osim toga, prati se pouzdanost dobivenih modela predviđanja, ovisno o količini podataka za vježbu. Uz pravilno odabrani raspon podataka za vježbu moguće je stvoriti modele predviđanja s pouzdanošću većom od 95 % s postignutom tolerancijom 2×10−6 mm.The paper deals with the comparison of usage of three basic types of neural units in order to create the most suitable model predicting determining the final thickness of the alumina layer formed at surface with current density of 1 A∙dm−2. In addition, the reliability of obtained prediction models, depending on the amount of training data, has been monitored. With properly selected range of training data it is possible to create prediction models with reliability greater than 95 % with achieved toleration 2×10−6 mm

The Influence of Input Factors of Aluminium Anodizing Process on Resulting Thickness and Quality of Aluminium Oxide Layer

AbstractIn order to optimize the technological process of aluminium anodic oxidation, the possibilities of usage of sodium chloride in the electrolyte has been studied, since very small concentration of sodium chloride allows us to reduce concentration of other components of the electrolyte. Also the influence of sodium chloride concentration in the electrolyte on the final thickness and quality of the formed anodic aluminium oxide (AAO) layer has been investigated in this paper. In contrast to common anodizing experiments, in which the influence of only one separate factor at a time is considered, in our research all relevant factors (four chemical factors) were varied simultaneously according to the methodology of statistical experimental design, i.e. design of experiments (DOE). Based on the evaluation of experimentally obtained data by application of mathematical-statistical methods and theory of neural networks, the relationship between the concentration of sodium chloride in the electrolyte and final thickness of the AAO layer was experimentally determined. Thanks to that it was possible to obtain the predictive model which can determine the final thickness of AAO layer. Moreover, the results of this research allows us to reduce the concentration of other components of the electrolyte up to the level of 25% of commonly used concentration of these electrolyte components designed for the process of aluminium anodic oxidation

Notes on the Solutions of the First Order Quasilinear Differential Equations

The system of the quasilinear differential first order equations with the antisymetric matrix and the same element f (t,x(t)) on the main diagonal have the property that r'(t) = f (t,x(t))r(t), where r(t) ≥ 0 is the po- lar function of the system. In special cases, when values f (t,x(t)) and g (t,x(t)) are only dependent on r^2 (t), t ∈ Jo we can find the general solution of the system (1) explicitly

Analiza čimbenika bočnog glodanja koji utječu na nepravilnost površine visokokvalitetnog čelika E295

The paper deals with experimental research and evaluation of side milling by evaluation of technology factors, which influence the surface profile parameter peak to valley of high-grade steel E295 by means of design of experiments. Four selected technological factors (diameter of milling cutter, spindle speed, feed per tooth and depth of cut) which enter into technological process of side milling of slots have been evaluated by means of full factories analysis. The surface quality has been evaluated by static quality characteristic the peak to valley Rz parameter. The multiple linear regression equation obtained after analysis of variance gives the level quality Rz as a function of the significant factors. Different factors main effect and their interaction significance have been found, which generated surface profile under defined conditions by side milling.U radu je prikazano eksperimentalno istraživanje i procjena bočnog glodanja pomoću procjene tehnoloških čimbenika koji utječu na parametar profila površine visokokvalitetnog čelika E295 pomoću pokusa. Četiri odabrana tehnološka čimbenika (promjer glodala, brzina osovine, sadržaj po zubu, dubina rezanja) koji spadaju u tehnološki proces bočnog glodanja utora ispitana su pomoću potpune analize čimbenika. Kvaliteta površine je ispitana pomoću Rz parametra. Višestruka jednadžba linearne regresije dobivena nakon analize varijance daje razinu kvalitete Rz kao funkciju važnih čimbenika. Uočen je glavni utjecaj raznih čimbenika i važnost njihova međudjelovanja, koji su dali profil površine u zadanim uvjetima pomoću bočnog glodanja

Analysis of physical factors on chosen properties of anodic alumina oxide (AAO) layers and environment

In the contribution is evaluated an impact of physical factors of anodizing process, namely the temperature of an electrolyte, anodizing time and voltage, on the change of values of Vickers microhardness and thickness of formed layer of experimental materials Al99∙5. By increasing of electrolyte temperature, the values of layer microhardness and thickness layer increase, namely about 0.78 % at the increasing of electrolyte temperature by 1 °C. By lengthening of anodizing time grows the value of layer thickness, but only to the value of the critical deposition time, when chemical dissolution of the layer start to be more prominent. By voltage increasing, values of layer thickness and micro-hardness are increased in the range of the used experimental values

Logistic Approach of Building and Development of Production Systems

The paper presents a complex of information aimed at automated production systems structures and simulation. For production systems intergrated structures formation it uses logistic principles for making the internal material flow among various logistic nodes more precise and effective, including respective information flow, here e. g. with use of integrable and compatibile handling and technological systems, as well

Enhancing Osteoconduction of PLLA-Based Nanocomposite Scaffolds for Bone Regeneration Using Different Biomimetic Signals to MSCs

In bone engineering, the adhesion, proliferation and differentiation of mesenchymal stromal cells rely on signaling from chemico-physical structure of the substrate, therefore prompting the design of mimetic “extracellular matrix”-like scaffolds. In this study, three-dimensional porous poly-L-lactic acid (PLLA)-based scaffolds have been mixed with different components, including single walled carbon nanotubes (CNT), micro-hydroxyapatite particles (HA), and BMP2, and treated with plasma (PT), to obtain four different nanocomposites: PLLA + CNT, PLLA + CNTHA, PLLA + CNT + HA + BMP2 and PLLA + CNT + HA + PT. Adult bone marrow mesenchymal stromal cells (MSCs) were derived from the femur of orthopaedic patients, seeded on the scaffolds and cultured under osteogenic induction up to differentiation and mineralization. The release of specific metabolites and temporal gene expression profiles of marrow-derived osteoprogenitors were analyzed at definite time points, relevant to in vitro culture as well as in vivo differentiation. As a result, the role of the different biomimetic components added to the PLLA matrix was deciphered, with BMP2-added scaffolds showing the highest biomimetic activity on cells differentiating to mature osteoblasts. The modification of a polymeric scaffold with reinforcing components which also work as biomimetic cues for cells can effectively direct osteoprogenitor cells differentiation, so as to shorten the time required for mineralization

Osobnost Alžběty Durinské a její zobrazení na deskových malbách na hlavním oltáři dómu sv. Alžběty v Košicích

Témou mojej bakalárskej práce je Osobnosť Alžbety Durínskej a jej zobrazenie na tabuľových maľbách hlavného oltára dómu sv. Alžbety v Košiciach z rokov 1474 - 1477. Alžbeta Uhorská, dcéra kráľa Ondreja II. a jeho manželky Gertrúdy, bola patrónkou mesta a dómu, kde je jej zasvätený hlavný oltár. V mojej bakalárskej práci by som chcela predstaviť jej osobnosť a legendy alžbetínskeho cyklu hlavného oltára tohto dómu. Zároveň sa bakalárska práca zaoberá problematikou autorstva tabuľových obrazov, ktorá je spornou témou historikov umenia.The topic of my bachelor work is Personality of Elizabeth of Hungary and her representation on panel paintings of main altar in Cathedral of Saint Elizabeth in Košice of years 1474 - 1477. Elizabeth of Hungary, daughter of king Andrew II. and his wife Gertrude, was a patron of town and cathedral, where the main altar is dedicated to her. In my bachelor work I want to present her personality and legends of Elizabethan cycle of main altar in this cathedral.At the same time, the thesis deals with the authorship of panel painting, which is a controversial topic of art historians.Institute of Christian Art HistoryÚstav dějin křesťanského uměníCatholic Theological FacultyKatolická teologická fakult