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EN
The aim of this work was to characterize the changes in microstructure and chemical composition of the austenitic overlays on a pressure vessel steel that occur in the vicinity of the interface between the overlay and the base material. The investigations were carried out on a 16Mo3 boiler pipes weld overlaid by 309 and 310 steels. The microstructural examinations were performed on longitudinal cross-sectioned samples. The qualitative and quantitative chemical composition analyses on metallographic samples were determined on Scanning Electron Microscopy (SEM) by means of Energy Dispersive Spectrometry (EDS). The article analyzes the influence of the solidification sequence in both types of steel on final microstructure.
EN
The article is devoted to the assessment of the geometrical structure of the surface as well as the mechanical and tribological properties of the surface layers obtained in the process of ion implantation. The titanium alloy Ti6Al4V used in biotribological systems was implanted with nitrogen and argon ions. Investigations of the geometrical structure of the surface before and after the tribological tests were carried out using confocal microscopy. The hardness of the tested materials was determined by the instrumental indentation method using a Vickers indenter. A nanotribometer was used for tribological tests. The tests were carried out in a reciprocating motion under conditions of technically dry friction and friction with the lubrication of Ringer's solution. SEM scanning microscopy was used to determine the width of the wear pattern and the wear mechanism. The conducted research showed that the hardness of the tested materials increased as a result of ion implantation. The tribological tests showed that the use of ion implantation improves the tribological properties, and the dominant wear mechanism was abrasive wear.
PL
Artykuł poświęcony jest ocenie struktury geometrycznej powierzchni oraz właściwości mechanicznych i tribologicznych warstw wierzchnich uzyskiwanych w procesie implantacji jonowej. Stop tytanu Ti6Al4V stosowany systemach biotribologicznych implantowano jonami azotu i argonu. Badania struktury geometrycznej powierzchni przed i po testach tribologicznych przeprowadzano przy użyciu mikroskopii konfokalnej. Twardość badanych materiałów wyznaczano metodą instrumentalnej indentacji przy zastosowaniu wgłębnika Vickersa. Do testów tribologicznych wykorzystano nanotribometr. Badania realizowano w ruchu posuwisto-zwrotnym w warunkach tarcia technicznie suchego oraz tarcia ze smarowaniem roztworem Ringera. Mikroskopię skaningową SEM wykorzystano do określenia szerokości śladu wytarcia oraz mechanizmu zużywania. Przeprowadzone badania wykazały, że w wyniku implantacji jonowej nastąpił wzrost twardości badanych materiałów. Testy tribologiczne wskazały, że zastosowanie implantacji jonowej wpływa na poprawę właściwości tribologicznych, a dominującym mechanizmem zużywania było zużycie ścierne.
PL
Badanie wyrobów włókienniczych odgrywa istotną rolę w systemie zapewnienia jakości tekstyliów, a także w pracach nad rozwojem nowych technologii i produktów włókienniczych. Istnieje wiele metod oceny struktury i właściwości włókien i wyrobów włókienniczych. Bardzo ważne miejsce wśród tych metod zajmują techniki mikroskopowe, w szczególności mikroskopia optyczna i skaningowa mikroskopia elektronowa (SEM). W artykule podano krótki przegląd możliwych zastosowań metod mikroskopowych do analizy efektów niektórych operacji wytwarzania tekstyliów. Wykorzystanie mikroskopu optycznego umożliwiło identyfikację przyczyn powodujących nierównomierność barwy wyrobów bawełnianych. Z przeglądu literatury oraz doświadczeń własnych autorów wynika, że metody mikroskopowe stanowią cenne narzędzie w badaniu włókien i wyrobów włókienniczych.
EN
Fabric testing plays an important role in the quality assurance system and in the development of new textile technologies and products. There are many test methods used to evaluate the structure and properties of fibers and textile materials. Among these methods, microscopic techniques – especially optical microscopy and scanning electron microscopy (SEM) – are one of the most important methods. This paper provides a brief overview of the possible uses the microscopic methods for determining the results of some textile manufacturing processes. A review of the literature and the authors experiences in this field indicate that microscopic methods are a valuable tool for the testing and assessing the performance of fibers and textile products.
EN
Nowadays sustainability is a contemporary and current issue that recognized by scholars and practitioners. While the concept of perceived corporate sustainability allows various sustainability views, still a lack of understanding arguably inhibits its practical realization and a proper understanding of sustainability is urgently needed. Therefore, the objectives of this paper are to identify the factors affecting perceived corporate sustainability practices (PCSP) and investigate the relationship between PCSP and organizational performance. A quantitative approach was deployed using Structural Equation Modelling (SEM) to analyse the responses from 203 managers for SMEs in Qatar. The study revealed that CSR practices, green practices, and corporate environmental strategy were found to significantly affect PCSP while top management support does not play an important role in it. Moreover, the study showed that PCSP significantly affects financial performance while the relationship between PCSP and none financial performance was not supported by the results. Furthermore, this research is expected to provide SMEs and sustainability literature with valuable suggestions for management practices.
PL
W dzisiejszych czasach zrównoważony rozwój jest współczesnym i aktualnym zagadnieniem, uznanym przez naukowców i praktyków. Chociaż koncepcja postrzeganego zrównoważonego rozwoju korporacyjnego pozwala na różne spojrzenia na zrównoważony rozwój, nadal brak zrozumienia prawdopodobnie utrudnia jego praktyczną realizację, a właściwe zrozumienie zrównoważonego rozwoju jest pilnie potrzebne. Dlatego celem tego artykułu jest zidentyfikowanie czynników wpływających na postrzegane praktyki korporacyjnego zrównoważonego rozwoju (PCSP) i zbadanie związku między PCSP a wydajnością organizacji. Zastosowano podejście ilościowe, wykorzystując modelowanie równań strukturalnych (SEM), aby przeanalizować odpowiedzi 203 menedżerów MŚP w Katarze. Badanie wykazało, że praktyki CSR, zielone praktyki i korporacyjna strategia środowiskowa znacząco wpływają na PCSP, podczas gdy wsparcie najwyższego kierownictwa nie odgrywa w tym ważnej roli. Ponadto badanie wykazało, że PCSP istotnie wpływa na wyniki finansowe, podczas gdy związek między PCSP a żadnymi wynikami finansowymi nie został poparty wynikami. Ponadto oczekuje się, że badanie to dostarczy MŚP i literaturze dotyczącej zrównoważonego rozwoju cennych sugestii dotyczących praktyk zarządzania.
EN
The improvement of poly(ethylene terephthalate) (PET) fibers flame retardancy is usually achieved by using antipyrenes, which may be incorporated into polyester molecules during polycondensation or are physically mixed with polymer in the fiber formation process. In this article we present an alternative method to reduce the flammability of PET fibers and fabrics which is analogous to dyeing them with a dispersed dyes in a high temperature bath. We have tested this method many times using various modifiers so far. This time, we applied a commercial organophilized montmorillonite Cloisite®15A (C15A). In the presented work, using Limited Oxygen Index (LOI) flammability tests and the thermogravimetric analysis (TGA) method, the effectiveness of the modification used was demonstrated and its optimal variant was determined. Based on Fourier Transform-Infrared Spectroscopy (FT-IR) studies, the existence of interactions between PET macromolecules and the C15A modifier in the entire temperature range of the oxidative degradation was confirmed. Using the Wide-Angle X-ray Scattering (WAXS) and Small-Angle X-ray Scattering (SAXS) methods, the basic parameters of the nanostructure of the studied fibers were determined, and their nanocomposite nature was confirmed. The most important goal, which was successfully achieved, was to explain the mechanism of flame inhibition by the applied modifier C15A.
PL
Poprawę właściwości palnych włókien poli(tereftalanu etylenu) (PET) można uzyskać w wyniku zastosowania uniepalniaczy, które mogą być wprowadzane do mieszaniny reakcyjnej podczas polikondensacji poliestru lub fizycznie mieszane z polimerem w procesie tworzenia włókien. W niniejszym artykule przedstawiono alternatywną metodę zmniejszania palności włókien i wyrobów tekstylnych z PET, analogiczną do procesu ich barwienia rozproszonymi barwnikami w kąpieli wysokotemperaturowej. Metodę tę testowaliśmy już wielokrotnie przy użyciu różnych modyfikatorów. Tym razem zastosowaliśmy handlowo dostępny organofilizowany montmorylonit Cloisite®15A (C15A). Za pomocą testów palności (określano wartość LOI – wskaźnika tlenowego) oraz analizy termograwimetrycznej (TGA) wykazano skuteczność zastosowanej modyfikacji i określono jej optymalny wariant. Na podstawie badań spektroskopowych FT-IR (spektroskopia w podczerwieni z transformacją Fouriera) potwierdzono występowanie oddziaływań między makrocząsteczkami PET i modyfikatora C15A w całym zakresie temperatury, obejmującym proces degradacji oksydacyjnej. Metodami szeroko i mało kątowej dyfrakcji rentgenowskiej (WAXS i SAXS) określono podstawowe parametry nanostruktury badanych włókien oraz potwierdzono ich nanokompozytowy charakter. Wyjaśniono także mechanizm inhibitowania płomienia przez zastosowany modyfikator C15A.
EN
ZnO thin layers were deposited on p-type silicon substrates by the sol-gel spin-coating method and, then, annealed at various temperatures in the range of 573-873 K. Photoluminescence was carried out in the temperature range of 20-300 K. All samples showed two dominant peaks that have UV emissions from 300 nm to 400 nm and visible emissions from 400 nm to 800 nm. Influence of temperature on morphology and chemical composition of fabricated thin layers was examined by XRD, SEM, FTIR, and Raman spectroscopy. These measurements indicate that ZnO structure is obtained for samples annealed at temperatures above 573 K. It means that below this temperature, the obtained thin films are not pure zinc oxide. Thus, annealing temperature significantly affected crystallinity of the thin films.
EN
The presented paper deals with the measurement methodologies of the structural properties of porous anodic alumina (PAA) films filled with YalO3:Tb3+ composite using X-ray diffraction, atomic force microscopy and scanning electron microscopy. It shows that the deposited material does not uniformly fill the porous volume of the anodic alumina film and the part of it forms a thick layer on the PAA surface. The aim of this work is to show the differences in the XRD response obtained at different angles of incidence of the excitation beam for the PAA/YalO3:Tb3+ system. Furthermore, this simple approach enables separation of the signal from both regions on the surface and inside the PAA pores, providing more accurate data interpretation. It reveals that the crystallization of the material on the PAA surface and within the pores is different.
PL
Stop odlewniczy aluminium AlSi12Cu1(Fe) poddano pasywacji w kąpieli opartej na związkach Cr(III). Test w atmosferze obojętnej mgły solnej wykazał, że dodatek do kąpieli związków fluorokompleksowych Zr w ilości 800 ppm przyczynił się do wytworzenia powłoki konwersyjnej o dłuższym działaniu ochronnym – nawet do 480 h, niż analogicznej powłoki, ale nie zawierającej cyrkonu (do kilkudziesięciu godzin). Analizy AFM oraz SEM wykazały, że w obecności fluorokompleksu Zr powstaje powłoka o sferoidalnej morfologii i rozwiniętej powierzchni, co miejscowo przejawiało się nawet w postaci drobnych spękań. Półilościowa analiza EDS wykazała w mikroskali znaczną nierównomierność rozmieszczenia pierwiastków na powierzchni aluminium pokrytego powłoką konwersyjną. Zaobserwowana segregacja pierwiastków tworzących powłokę (m.in. Cr, Zr, F, O) dobrze korelowała z mikrostrukturą i rozmieszczeniem faz charakterystycznych dla tego stopu aluminium.
EN
AlSi12Cu1(Fe) cast alloy was subjected to passivation in the bath using Cr(III) compounds. Neutral salt spray test showed that the addition to the bath of fluorocomplex zirconium compounds in the amount of 800 ppm contributed to the formation of a conversion coating with a longer protective effect – up to 480 hours, than the analogous coating, but without zirconium (up to several dozen hours). AFM and SEM analyzes showed that in the presence of a zirconium fluorocomplex, a coating with a spheroidal morphology and developed surface is formed, which even manifested locally in the form of small cracks. Semi-quantitative EDS analysis showed on a microscale a significant inhomogeneity in the distribution of elements on the surface of aluminum covered with a conversion coating. The observed segregation of the elements forming the coating (including Cr, Zr, F, O) well correlated with the microstructure and phases distribution characteristic of this aluminum alloy.
EN
A total of 15 Navicula taxa were recorded in epilithic communities occurring in seven rivers of Serbia, all of which are new to the diatom flora of Serbia. The most interesting of them are N. splendicula and N. moskalii. When observing N. splendicula specimens under SEM, we noticed a characteristic silicate tongue in the center of raphe ends, which had not been previously reported in the available literature. The insufficiently researched distribution of N. moskalii and scarce autecological information on the taxon prompted us to provide new details about the species in this study. These findings clearly indicate the need for further comprehensive research that would provide new information on rare taxa.
EN
In this research work, polymer coated magnetic nanoparticles were prepared by co-precipitation method. The samples were characterized by XRD, SEM, EDS, VSM and two probe DC conductivity measurements. XRD pattern indicated the existence of a sole cubic phase of Fe3O4 with Miller indices (2 2 0), (3 1 1), (5 1 1), (4 4 0). An average size of magnetic nanoparticles was about 22.9 nm and it was reduced to 21.3 nm and 19.4 nm after 1 wt. %. and 2 wt. % coating of PEG-6000, respectively. The morphology and size of the samples were investigated by scanning electron microscope (SEM). EDX spectra confirmed the coating of PEG on magnetic nanoparticles. Magnetic properties were examined by vibrating sample magnetometer (VSM). Saturation magnetization (Ms) decreased as the concentration of PEG increased in the magnetic material. Electrical properties of uncoated and polymer coated Fe3O4 nanoparticles were studied by two-probe conductivity meter. This study concluded that the thermal flow of charge in polymer coated magnetic nanoparticles can be evaluated at micro and nano level.
EN
Without the use of appropriate recycling technologies, the growing amount of electronic waste in the world can be a threat to the development of new technologies, and in the case of improper waste management, may have a negative impact on the environment. This is due to the fact that this waste contains large amounts of valuable metals and toxic polymers. Therefore, it should be recycled in accordance with the assumptions of the circular economy. The methods of mechanical recovery of metals from electronic waste, including printed circuits, may be widely used in the future by waste management companies as well as metal production and processing companies. That is why, a well-known and easily applicable electrostatic separation (ES) method was used to recover metals from printed circuit boards. The grain class of 0.32 - 0.10 mm, obtained after grinding the boards, was fed to a separator. Feed and separation products were analyzed by means of ICP-AES, SEM/EDS and XRD. The concentrate yield obtained after electrostatic separation amounted to 32.3% of the feed. Its density was 11.1 g/cc. Out of the 91.44% elements identified in the concentrate, over 90% were metals. XRD, SEM observations and EDS analysis confirmed the presence of non-metallic materials in the concentrate. This relatively high content of impurities indicates the need to grind printed circuit board into grain classes smaller than 0.32-0.10 mm.
EN
This study contains an analysis of the main determinants of the inflow of foreign direct investment to Poland. This article is devoted to the analysis of the main motives determining the inflow of foreign direct investment to Poland. It is the second part of the series and presents the scale and dynamics of FDI inflow to Poland between 2010 and 2018, as well as the results of own research carried out using structural equation modeling. This study focused on determining the cause-and-effect relationship between the scale of inflow of foreign direct investment and selected macroeconomic parameters of the economy. Based on the theories and results from previous research, a model was developed in which the variables and the nature of their relationship were determined. The model is based on four latent exogenous variables describing FDI determinants and one latent endogenous variable describing FDI inflow. In the article, structural equation modeling was indicated as a method for analyzing the factors conditioning the inflow of foreign direct investment. The proposed research concept will allow supplementing and extending the analysis of FDI determinants in Poland.
PL
Artykuł poświęcony jest analizie głównych motywów warunkujących napływ zagranicznych inwestycji bezpośrednich do Polski. Stanowi drugą część cyklu i przedstawia skalę oraz dynamikę kształtowania się BIZ w Polsce w latach 2010-2018, a także wyniki badań własnych przeprowadzonych przy wykorzystaniu metody modelowania równań strukturalnych. Badania koncentrowały się na określeniu związku przyczynowo-skutkowego między skalą napływu bezpośrednich inwestycji zagranicznych i wybranymi parametrami makroekonomicznymi gospodarki. Na podstawie teorii oraz wyników dotychczasowych badań zbudowano model, w którym określono zmienne i charakter relacji między nimi. Model bazuje na czterech ukrytych zmiennych egzogenicznych opisujących determinanty BIZ oraz jednej ukrytej zmiennej endogenicznej, tj. napływ BIZ. W artykule do analizy czynników warunkujących napływ bezpośrednich inwestycji zagranicznych wskazano metodę równań strukturalnych. Zaproponowana koncepcja badawcza pozwoli na uzupełnienie i rozszerzenie analiz dotyczących determinant BIZ w Polsce.
EN
This study examines the flexural strength and compressive strength of the mortars, which were mixed with the electromagnetic field treated water (EMFTW) and contained fly ash. EMFTW was obtained by passing the tap water through an electromagnetic field. The test variable was the fly ash content in place of cement and the water treated with EMFTW in place of the tap water. The results show that the flexural and compressive strength of the mortar samples mixed with MFTW is 12.56% and 15.8% higher than that prepared with the tap water, respectively. It was also found that the magnetized water improves the resistance to bending and compression by 12.67% and 4.35% to that prepared with the tap water and 10% fly ash instead of cement.
EN
The aim of this work was to study the impact of various fabrication methods used to prepare high entropy alloys based on the AlFeMnNbNiTi system. Chemical composition was customized to ensure a solid solution structure with precipitation of the Laves phase. The three manufactured alloys were prepared by melting, but with the use of various input materials and different furnaces in protective atmospheres. After the melting process, heat treatment was carried out. Structures of obtained materials were analyzed by means of a Scanning Electron Microscope (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) mapping. Mechanical properties were represented by Vickers hardness. In this paper, impact of the use of low purity input materials is shown, as well as differences in structure resulting from the utilization of different melting furnaces.
EN
In 2019, the first basalt fiber production line was created in Poland. The fiber is produced in a continuous process, according to the technology developed by Polski Bazalt S.A. In order to assess the microstructure of the manufactured product, a number of tests were carried out, according to previously developed procedures. The presented results relate to the study of the basalt fiber microstructure using light microscopy, electron microscopy and atomic forces. The research was aimed at characterizing the fibers, but also developing research procedures that allow assessment of the basic fiber parameters under post-production conditions. The research was conducted in the field of quantitative and qualitative assessment of the basalt fiber microstructure, its diameter, and the size distribution of this value. In addition, attempts were made to assess the thickness of the sizing (as an impregnation layer) on the fibers obtained employing different parameters of the drawing process and various types of impregnation. Based on the obtained results, measurement and research procedures were implemented in the quality control system of the Polski Bazalt company. Tests carried out as part of these procedures confirm the repeatability in terms of the quality and diameter of the produced fiber.
EN
Rice Husk (RH) is an agricultural waste which is produced in huge amounts from the milling process of paddy rice. Rice Husk Ash (RHA) is a by-product material obtained from the combustion of rice husk. The amorphous silica-rich RHA (84-90 wt%) has a wide range of applications. This research focused on the possibility of utilizing RHA in the process of developing a mortar with low thermal conductivity to enhance the thermal comfort in concrete and masonry buildings. The thermal conductivity of mortar was determined by Lee’s Disc method, and the results were compared to the data for conventional mortar as well as commercial thermal insulation materials. The results indicate a significant reduction in thermal conductivity in the mortar developed with RHA
PL
Łuska ryżowa (Rice Husk, RH) jest odpadem rolniczym, który jest produkowany w ogromnych ilościach w procesie mielenia ryżu niełuskanego. Popiół z łuski ryżowej (Ryż Husk Ash – RHA) jest produktem ubocznym uzyskiwanym w procesie spalania łuski ryżowej. Bogaty w krzemionkę amorficzną RHA (84-90 % mas.) ma wiele zastosowań. Badania te skupiały się na możliwości wykorzystania RHA w procesie opracowywania zaprawy o niskiej przewodności cieplnej w celu zwiększenia komfortu cieplnego w budownictwie betonowym i murowym. Przewodność cieplną zaprawy określono metodą Lee's Disc, a wyniki porównano z danymi dla zaprawy konwencjonalnej oraz handlowych materiałów termoizolacyjnych. Wyniki wskazują na znaczne obniżenie przewodności cieplnej w zaprawie opracowanej przy użyciu RHA.
EN
Electrospun materials are good candidates for the design of tissue regeneration scaffolds as they can simulate the natural surroundings of tissue cells. The study proposes electrospun polycaprolactone (PCL)/cefuroxime (CFU) scaffolds for human cell culture and investigates the influence of the antibiotic content on scaffold morphology, thermal and mechanical properties. The increase in the CFU concentration resulted in the reduction of fiber diameter and number of deformations. It also influenced the reduction of scaffold thermal enthalpies and improved scaffold break strength. With regard to cell growth, the scaffolds showed precedence in greater colonization of the HeLa cells. Finally, these scaffolds showed compatibility with standard human cell lines, and thus they can be used for the repair of damaged tissues.
EN
Embroidery can be applied to improve esthetic or functional properties of products. However, the expected appearance of the original design may be discarded by unsuitable selected technological parameters of embroidery machine. Thus, the influence of the technological parameters and embroidery thread types on the embroidery geometric parameters and on tension characteristics of embroidery has been investigated in this research. The research results revealed that the changes in geometry parameters of the designed digital image compared with the ones of actual embroidery samples are dependent on embroidery filling type, stitch density, and thread type. Mechanical testing of the embroidery elements has proved that embroidering influences the decrease in material breaking force and elongation at break compared with their initial tension characteristics.
EN
Bismuth niobate (BiNbO4) ceramics were fabricated by mixed oxide method and sintered by presureless sintering method. BiNbO4 ceramics doped with V2 O5 additive in amount 0.125 wt%, 0.250 wt% and 1 wt% of was sintered at T = 910°C whereas BiNbO4 ceramics doped with 2 wt% of CuO additive was sintered at T = 890°C and T = 910°C. It was found that V2 O5 additive improved morphology of the ceramic samples. However, the chemical composition of BiNbO4 ceramics in relation to bismuth oxide and niobium oxide manifested a tendency of lack of Bi2 O3 component. Absorption bands for the BiNbO4 compound were identified. FTIR band positions associated with NbO6 octahedra suggested that the crystal structure changes after V2 O5 incorporation.
EN
La0,7 Ca0,3 MnO3 polycrystalline were synthesized from La2 O3 , CaO and MnO2 powder mixture using a solid state reaction technique. The compound powders were obtained through the free sintering method at different temperatures and sintering times in order to study the influence of technological conditions on Ca doped La manganites. The most important physical features as structure, microstructure and morphology were described after X-ray diffraction investigation. Photographs of the specimen fractures were taken with SEM (scanning electron microscope) and they revealed high porosity of the tested material and great tendency for its grains to create agglomerates. Influence of doping and technological conditions on lattice parameters were studied by means of Rietvield analysis. The XRD measurements reveal that La0,7 Ca0,3 MnO3 has orthorhombic symmetry with Pnma space group.
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