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1

Non-invasive analysis and visualization of objects from FSW AlSi9Mg/2017A aluminum alloy joints

Wójcicka A., Mroczka K., Kowalski M.

Metallurgy and Foundry Engineering

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2018

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Vol. 44, no. 3

145--152

EN

Friction stir welding (FSW) technology allows for the welding of materials that differ in their chemical compositions, microstructures, and properties. When selecting the parameters, it is necessary to analyze the structure of a weld and eliminate the defects. The use of X-ray microtomography creates the possibility of precise imaging of a joint structure – especially when it contains defects (voids). The tests were carried out on an FSW joint made with both 2017A and AlSi9Mg aluminum alloys. The macrostructure was cross-sectional, and a defect was found in the middle part of the joint and on the advancing side. We used a conventional method of observation light microscopy. Then, an analysis was performed using X-ray microtomography, which revealed the shape of the defect in 3D. Individual cross-sections were extracted, which enabled us to measure the geometric quantities. A dependence was found for the shape of the defect on the welding parameters and the variability of its construction. The usefulness of this advanced material imaging technology for the analysis of FSW welds has been confirmed.

PL

Technologia FSW umożliwia zgrzewanie materiałów różniących się składem chemicznym, mikrostrukturą i właściwościami. Przy doborze parametrów konieczna jest analiza struktury złącza i eliminacja ewentualnych wad. Zastosowanie mikrotomografii komputerowej umożliwia precyzyjne obrazowanie budowy złącza, szczególnie gdy zawiera wady (pustki). Badania przeprowadzono na złączu FSW stopów aluminium 2017A i AlSi9Mg. Zbadano makrostrukturę na przekroju poprzecznym i stwierdzono obecność wady w środkowej części złącza i po stronie natarcia. Zastosowano konwencjonalną metodę obserwacji – mikroskopię świetlną. Następnie wykonano analizę złącza z zastosowaniem tomografii komputerowej, która ujawniła kształt wady w wymiarze 3D. Wyekstrahowano poszczególne przekroje, które umożliwiły wykonanie pomiarów wielkości geometrycznych. Stwierdzono zależność kształtu wady od parametrów zgrzewania oraz zmienność jej budowy. Potwierdzono przydatność tej zaawansowanej technologii obrazowania budowy materiałów do analizy złącz FSW.

2

Syntezy pochodnych 2,7-naftyrydyny

Wójcicka A.

Wiadomości Chemiczne

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2017

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[Z] 71, 5-6

349--379

EN

2,7-Naphthyridines have been the least known from all of the six structural isomers of pyridopyridines. The broad spectrum of biological activity of 2,7-naphthyridine derivatives [1] is the main of reason for obtaining of the new compounds containing this scaffold (Fig. 1). Gabriel and Colman were the first to obtain isomer 2,7-naphthyridine in 1902 and they called it ‘copiryne’ (Fig. 2) [2]. The goal of this study is the presentation of various methods for the preparation of 2,7-naphthyridine derivatives. Compounds containing copyrine scaffold can be obtained from a different substrates, but that synthesis may be classified into three main categories: from pyridine derivatives, from quinoline derivatives and from other compounds. Most of 2,7-naphthyridines have been synthesized by cyclocondensation (Scheme 5, 7–10, 13–14, 16–18, 20, 28–29, 32, 35–36) or intramolecular cyclization (Scheme 1–4, 6, 11–12, 15, 19, 21–25, 30–31, 33–34, 38) of pyridine derivatives by annulation of the other pyridine ring [3–24, 27–31]. Intramolecular rearrangement of pyrrolo [3,4-c] pyridines (Scheme 26–27) and pyrano [3,4-c] pyridine or thiopyrano [3,4-c] pyridine (Scheme 35–37) also gave the 2,7-naphthyridine scaffold [32-34]. There are also many syntheses of benzo[c][2,7]naphthyridine, benzo [f] [2,7] naphthyridine or benzo [ c,f] [2,7] naphthyridine scaffolds, in which the substrates are quinoline derivatives (Scheme 39–48) [35–43]. 2,7-naphthyridines have been least often obtained by cyclocondensation of non-cyclic substrates (Scheme 49–53) [44–49].

3

Dwuetapowa metoda eksploracji danych pozyskiwanych z obrazów cyfrowych

Wójcicka A., Simiński R., Wróbel Z.

Studia Informatica

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2015

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Vol. 36, nr 1

145--154

EN

The main purpose of the paper is detailed analysis of the problem of knowledge extraction from images and to described a two-stage method which integrates digital image analysis focused on the extraction of quantitative and qualitative features and the knowledge extraction methods that use data mining analysis.

4

Analiza metod predykcji parametrów zgrzewania złącz metodą Friction Stir Welding

Wójcicka A., Simiński R., Wróbel Z.

Studia Informatica

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2014

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Vol. 35, nr 2

91--100

EN

W artykule przestawiono koncepcję systemu typowania parametrów zgrzewania z ukierunkowaniem na uzyskanie pożądanych właściwości mechanicz-nych złącz wytwarzanych metodą Friction Stir Welding. Proces decyzyjny uzupełniono modułem analizy i przetwarzania obrazów mikroskopowych złącz. Ekstrakcja reguł eksperckich zostanie przeprowadzona z wykorzystaniem narzędzi opierających się na metodach wywodzących się z teorii zbiorów przybliżonych.

PL

This article presents concepts of system for selection welding parameters of FSW joints. The decision making process, supplemented by module of analysis and processing microscopic image of the joints. Data mining of expert rules carried out using tools based on methods derived from the theory of rough sets.

5

Syntezy pochodnych układu pirazolo[4,3-c]heterocyklicznego

Wójcicka A.

Wiadomości Chemiczne

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2013

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[Z] 67, 11-12

1075--1104

EN

The broad spectrum of biological activity of pyrazolo[4,3-c]heterocyclic derivatives is the main of reason for the preparation of new compounds containing this scaffold. This review presents most of the literature data on the synthesis of pyrazolo[ 4,3-c]heterocyclic derivatives. This isomer system containing pyrazole moiety condensed with a heterocyclic ring can be synthesized from a different substrates, but that synthesis may be classified into two main categories: annulation of the pyrazole ring onto heterocyclic derivatives or annulation of the heterocyclic ring onto pyrazole analogs. The main goal of this study is the presentation of various methods for the preparation of the pyrazolo[4,3-c]pyridine (Rys. 2) [1–15], pyrazolo[4,3-c] quinoline (Rys. 3) [16–63], pyrazolo[4,3-c]isoquinoline [64, 65], pyrazolo[4,3-c] naphthtyridine [66–68], pyrazolo[4,3-c]thiazine [69–72], pyrazolo[4,3-c]cinnoline [73, 74], pyrazolo[4,3-c]quinolizine [75], and pyrazolo[4,3-c]pyridazine [76] derivatives.

6

Synteza i aktywność biologiczna pochodnych pirolo [3,4-c]pirydyny

Wójcicka A.

Wiadomości Chemiczne

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2013

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[Z] 67, 3-4

251--276

EN

Pyrrolo[3,4-c]pyridine is one of the six structural isomers of the bicyclic ring system containing pyrrole moiety condensed with a pyridine nucleus. This review presents most of the literature data about synthetic pyrrolo[3,4-c]pyridine derivatives and their biological activity. S. Gabriel and J. Colman [4] discovered this isomer for the first time and named it “merimine” [Fig. 3]. The main goal of this study is the presentation of various methods for the preparation of pyrrolo[3,4-c]pyridine derivatives. Compounds containing the pyrrolo[3,4-c]pyridine scaffold can be synthesized from different substrates, but the syntheses may be classified into two main categories: annulation of pyrrole ring onto pyridine derivatives or annulation of pyridine ring onto pyrrole derivatives. Biological investigations have shown that pyrrolo[3,4-c]pyridine derivatives have a wide spectrum of actions. Most of them have been studied as analgesic and sedative agents [35–40]. Antitumor [19, 42, 45], antiviral [27], antituberculostatic [43] activities have been found. Pyrrolo[3,4-c]pyridine derivatives can also be used in the treatment of nervous [20, 41] and immune [19, 42] system diseases.

7

Importance of epicuticular wax cover for plant/insect interactions: experiment with cereal aphids

Wójcicka A.

Polish Journal of Ecology

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2013

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Vol. 61, nr 1

183--186

EN

The epicuticular wax is the contact point between plants and the environment and plays a crucial role in mediating biotic and abiotic interactions. The associations between the content of epicuticular waxes, on surface plants of winter triticale with their acceptance by the grain aphid Sitobion avenae and bird cherry -oat aphid Rhopalosiphum padi were studied. In general, waxy genotype DED 1137 of winter triticale was less accepted by the cereal aphids than the wax less one (RAH 366). The waxy genotype decreased density of cereal aphids, prolonged maturity and decreased fecundity. Moreover, the comparison of abundance, development and fecundity of the aphid species on the triticale genotypes proved that tested genotypes differed in susceptibility to Sitobion avenae and Rhopalosiphum padi. The importance of the epicuticular wax compounds in the acceptance of plants by the aphids is discussed. The results indicated that aphids fed on waxy plants showed longer time of the prereproductive period and much lower total fecundity. Furthermore, waxy genotype reduced value of the cumulative aphid index and percentage of infested plants.

8

Synteza i aktywność biologiczna pochodnych 2,6-naftyrydyny

Wójcicka A., Wagner E.

Wiadomości Chemiczne

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2012

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[Z] 66, 3-4

297-318

EN

2,6-Naphthyridine is one of the six structural isomers of pyridopyridines. This review presents most of the literature data about natural and synthetic 2,6-naphthyridine derivatives and their biological activity. The main goal of this paper is to present various methods for the preparation of 2,6-naphthyridine analogues. Compounds containing 2,6-naphthyridine moiety can be synthesized from different substrates. Most of them have been obtained by cyclocondensation of various pyridine derivatives. During the past twenty years the biological activity of 2,6-naphthyridines have been studied. Presented compounds exhibit anticancer [21, 41], antihypertension [10], and antidepression [25] activity. Some of them can be used in the treatment of heart diseases [22], appetite disturbance, and obsessive states [43, 44]. 2,6-Naphthyridine derivatives with different molecular targets, e.g. topoisomerase [41], SERT [27], and protein kinases [21, 22] inhibitors have also been reported. Many of the 2,6-naphthyridine analogues are histamine H3 [27] and serotonine 5-HT2 [42–44] receptor antagonists.

9

Calibration of a credit rating scale for Polish companies

Wójcicka A.

Operations Research and Decisions

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2012

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Vol. 22, No. 3

63--73

EN

Increasing number of bankruptcy announcements means that even greater attention is being paid to the correct evaluation of the probability of default (PD) and decisions made on the basis of it. Reliable estimation of the likelihood of a company’s bankruptcy reduces risk, not only for the company itself but also for all co-operating companies and financial institutions. The financial crisis has led to a tightening up of the conditions for gaining finance from banks. However, it is not only the evaluation of PD itself that is so important but also the correct classification of companies according to their PD level (“good” or “bad” companies). There is very little consideration about possible adjustments of the credit risk scale, as usually the American scale is adopted with no changes which seems incorrect. This paper stresses the importance of correct calibration of the credit rating scale. It should not be assumed (as it was in the past) that once a scale is defined it remains fixed and independent of the country. Therefore, the research carried out on Polish companies shows that the credit rating scale should be changed and the default point (i.e. “cut-off” point) should be higher than in the past. The author uses a modified classification matrix based on the probability of default. The paper compares the classification of quoted Polish companies according to their credit risk level (PD) with the actual occurrence of default when various default “cut-off” points are used.

10

The influence of friction stir welding process on structure and mechanical properties of the AlSiCu/SiC composites

Kurtyka P., Sulima I., Wójcicka A., Ryłko N., Pietras A.

Journal of Achievements in Materials and Manufacturing Engineering

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2012

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Vol. 55, nr 2

339--344

EN

Purpose: The aim of this study was to explain the influence of the friction stir welding on the size and distribution of reinforcement particles in the composite AlSiCu/SiCp, as well as determine its mechanical properties. Design/methodology/approach: Aluminium alloy reinforced with 10% vol. SiC particles with an average size of 15 microns has been joined using friction stir welding method. The joining process were carried out at rotation speed 560 rpm and linear velocity of 355 mm/min and the temperature was lower than 793 K. Microstructures of joined materials were observed according to the light and scanning electron microscopy. Changing of distribution of reinforcement particles were analysed by new RVE theory. The mechanical properties determined on the basis of compression tests. Tests were performed at room temperature at a strain rate 10-4s-1. Findings: In the resulting joints (welds) observed significant changes in the distribution of SiC particles, precipitation which was characterized by macro-heterogeneity. However, in micro scale, a few typical distributions and areas of fragmentation of the reinforcing particles were identified. Differences in the sizes of the ceramic particles were 15 microns in the initial material and 2-3 micron in the welded material, respectively. The analysis of these regions using the new RVE theory shows that the coefficient of mechanical properties anisotropy was varied from 0.500328 to 0.016961. Mechanical testing of selected parts of joints showed significant differences in the values of the plastic flow stress in advancing and retreating sides, approximately from 400 to 450 MPa. Practical implications: The obtained results can be used to optimize the welding process composites by friction stir welding. In addition, the analysis results may be used to design new methods to modify aluminium matrix composites reinforced with ceramic particles. Originality/value: The work provides information on the influence of the FSW process on the change distribution and fragmentation of reinforcing particles and mechanical properties of composites joints.

11

Aktywność biologiczna pochodnych 2,7-naftyrydyny

Wójcicka A., Wagner E.

Wiadomości Chemiczne

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2011

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[Z] 65, 3-4

235-264

EN

2,7-Naphthyridine is one of the six structural isomers of pyridopyridines. More than one hundred years ago, Gabriel and Colman discovered the isomer 2,7-naphthyridine, and named it “copiryne” [3]. From among of all naphthyridines, the synthesis and properties of the copyrine derivatives have not yet been thoroughly investigated. This paper reviews the synthetic and natural 2,7-naphthyridine derivatives which have been reported to possess various biological activity. A large number alkaloids containing the 2,7-naphthyridine scaffold have been isolated from plants and marine organisms [13–18]. The natural marine alkaloids can be classified into two groups. The bicyclic lophocladines were isolated from the red alga Lophocladia sp. [12]. The pyridoacridines represent a large and growing class the polycyclic alkaloids from sponges, ascidians or tunicates [15, 16]. Many of this natural compounds exhibited cytotoxic, antibacterial, antiviral, antifungal and sedative activity. The broad spectrum of biological activity of copyrine alkaloids is the main of reason for the preparation of new 2,7-naphthyridine derivatives also by the synthetic route. So far, about fifty different methods of synthesizing the 2,7-naphthyridine ring have been published. This study described synthesis only biologically active 2,7-naphthyridine analogues. Biological investigations have shown that copyrine derivatives have a wide spectrum of actions. Antitumor, antimicrobial, analgesic and anticonvulsion activities have been found. Most of 2,7-naphthyridine derivatives have been studied as antitumor agents. Many papers described synthesis and pharmacological properties the best active and highly selective PDE5 inhibitor (T-0156) [55]. So far, none of 2,7-naphthyridine derivatives has been applied as a drug.

12

Synthesis, Structure, and Pharmacological Screening of 2,7-Naphthyridine Derivatives

Wagner E., Wójcicka A., Bryndal I., Lis T.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 2

207-215

EN

An attempt to rearrange pyrrolo[3,4-c]pyridine-1,3-diones to the 2,7-naphthyridine ring under the conditions, described in only one report [1], gave compounds 7-9, but did not yield the expected 2,7- or 2,6-naphthyridine isomers. Important for the synthesis of the naphthyridine ring from pyrrolo[3,4-c]pyridine was that, of the two possible isomers, only 2,7- not 2,6-naphthyridine was obtained. Ethyl (4-R'-1,3- dioxo- 6-phenyl-1,3-dihydro-2H-pyrrolo[3,4-c]pyridin-2-yl)acetate (5, 6, 10) treated with sodium ethoxide was rearranged by the Claisen-Dieckmann reaction to ethyl 4-hydroxy-8-R'-1-oxo-6-phenyl-1,2-dihydro-2,7-naphthyridine-3-carboxylate (13, 14), where R' = methyl or ethoxy. The structures of the new compounds were confirmed by elemental analysis and NMR and IR spectra. The structure of 14 was also determined by X-ray crystallography to prove the presence of 2,7-naphthyridine isomer. The in vitro anticancer activities of the final 2,7-naphthyridines were tested at the US NCI (Bethesda, MD). Compound 13 exhibited cytostatic activity in vitro.

13

Synteza i charakterystyka zapachowa izomerycznych alifatycznych tridekanonów i ich pochodnych

Gibka J., Góra J., Wójcicka A.

Zeszyty Naukowe. Chemia Spożywcza i Biotechnologia / Politechnika Łódzka

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2002

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Z. 66

85-90

PL

W artykule opisano syntezę mało znanych w literaturze chemicznej alifatycznych, metamerycznych tridekanonów oraz ich pochodnych, takich jak acetale etylenowe, propylenowe, alkohole i ich octany. Zsyntezowane związki poddano ocenie zapachowej i określono próg wyczuwalności zapachu. Okazało się, że w tej grupie znajdują się związki o interesujących walorach zapachowych.

EN

Authors have been prepared a series of 7 aliphatic, isomeric tridekanones and their derivatives such alcohols, acetates, ethylene and propylene acetates. These compounds differ in the position of functional group. The flavour and odor tresholds concentration of syntesized compounds have been determined. As was expected the odors most of the derivatives were interesting.