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EN
Purpose: Silica/silicate scale is a significant problem, especially in oilfield production during Alkaline Surfactant Polymer (ASP) flooding, where chemical inhibitors are the preferred method to prevent them. In this study, the effect of inhibitor vinyl sulfonated copolymer (VS-Co) on silica/silicate scale formation was analysed using X-Ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). Design/methodology/approach: The functional group type of VS-Co are sulfonate ions, SO3-, and these interact in the scaling process. Bulk-inhibited scaling brine tests were conducted at 60°C and pH 8.5. During these tests, the silicon brine (with VS-Co) representing the inhibited ASP leachate was mixed with a magnesium brine representing the connate water to replicate reservoir conditions during ASP flooding. The samples tested in this study were non-inhibited Si/Mg mixed brine of 60 ppm Mg2+ and 940 ppm Si4+ (60Mg:940Si) as a blank, and inhibited 60Mg:940Si mixture with various VS-Co concentrations of 20 ppm, 50 ppm, and 100 ppm. The inhibition efficiency of the VS-Co was determined, followed by the characterisation study of the silica/silicate scale deposited from both test conditions. Findings: The IR spectra of all 60Mg:940Si samples show a similar peak at 1050 cm-1 to 1080 cm-1, attributed to a Si-O covalent bond and a band at 790 cm-1 to 800 cm-1 showing the presence of Si-O-Si stretching. XRD patterns produced a broad scattering peak for all samples at 2θ of 24° showing that the samples are amorphous silica. For tests of high Mg2+ in the brine mix, 900Mg:940Si, a mix of crystalline silica and crystalline magnesium silicate was produced. Based on these results, it can be concluded that the scale formed even with 100 ppm of VS-Co present. Further studies are required to address how to mitigate scale formation effectively in the future. Research limitations/implications: Based on the research conducted, we can conclude that the VS-Co alone could not significantly inhibit the formation of silica/silicate scale even at the highest concentration (100 ppm) of VS-Co. However, having VS-Co present caused an alteration in IR spectra frequency which requires further investigation to assess how best to develop the inhibiting properties of the VS-Co product. The application of nanoparticles and their successful stories spark the interest of authors in searching for an efficient method of managing the silica/silicate scale where the modification of potential scale inhibitor (SI) with nanoparticles may be able to improve the inhibition efficiency towards the silicate/silicate scale. Practical implications: The presence of VS-Co in the scaling brine only slightly inhibits the Mg2+ ion (initially comes from connate water) from reacting. It is worth further investigation on how this VS-Co can make it happen. Hence, the functional groups responsible for this may be altered by adding other functional groups to provide a synergistic effect in preventing this silica/silicate scale; or by modifying the VS-Co with nanoparticles to improve their adsorption/desorption capacity. Originality/value: The newly developed technique in analysing the inhibition mechanism of a chemical inhibitor using various spectroscopic analysis is promising where an alteration in the spectra may provide proof of the chemical’s inhibition efficiency.
EN
As a solid waste, the associated disposal cost of fly ash is really high. Previous studies suggested that the utilization of fly ash to treat heavy metal-contaminated soils was a new cost-effective method of disposal of it. Therefore, the effectiveness of fly ash stabilized/solidified Zn-contaminated soils has been investigated by unconfined compressive strength (UCS) and toxicity characteristics leaching procedure (TCLP) tests. Quantitative analysis of the soil microstructure was conducted by processing the X-ray diffraction (XRD) and scanning electron microscope (SEM) images. Mercury intrusion porosimetry (MIP) was carried out to illustrate the size and proportion of pore size for specimens under different ratios. The results of the tests showed an improvement in the UCS, which further increased as the content of binders was raised. Binder content would have little influence on the development of strength if the binder content exceeds a threshold value. The leached Zn2+ concentration of stabilized specimens was significantly decreased compared to that of untreated. Quantitative analysis confirmed that the addition of the binders resulted in the amount of hydration product, reduction of porosity, and a really random pores orientation, which was responsible for the improvement of the strength and leaching properties of the Zn2+ contaminated soils.
EN
The present study reports an easy eco-friendly, cost efficient, and rapid method for the synthesis of silver nanoparticles (Ag NPs) using palm sprouts as reducing cum capping agent. Green synthesis of silver nanoparticles was successfully performed using palm sprouts plant extract via a simple and cheaper eco-friendly method. Palm sprouts extract reduces silver nitrate to silver nanoparticles. The resulting materials were analyzed by Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD) analysis. FT-IR spectrum confirms the presence of various functional groups in the active biomolecules, it acts as a capping agent for the nanoparticles. The morphology of this sample was analyzed through SEM and the presence of silver was confirmed accordingly. The green synthesized Ag NPs exhibited an excellent antibacterial activity against E. coli and P. aeruginosa and B. subtilis and S. aureus besides imparting efficient antimicrobial activity against pathogenic bacteria as well.
EN
Measurements of the magnetic susceptibility (MS) in sedimentary sequences can quickly provide information on the variability of their mineral composition. A typical application of MS is the reconstruction of the supply of terrigenous material in car¬bonate rocks or the variability of the ratio of ferromagnetic to paramagnetic /diamagnetic minerals in clastic rocks. The article discusses the practical aspects of using the Bartington's portable apparatus for magnetic susceptibility probing along with the correlation of these results with the mineral composition obtained from X-ray diffraction tests. The analysed rock material was red and green clays from the vicinity of Częstochowa, assigned to the mud-evaporite Ozimek Member, Grabowa Formation (Keuper facies, Upper Triassic). The obtained results indicate the possibility of a correlation between the MS and the composition of rock-forming minerals in the studied sediments, where in green clays the magnetite/maghemite with pyrrhotite(?) does not substantially affect the MS, and para- and/or diamagnetic minerals have a decisive role. In the red clays the dominant MS carrier is the hematite.Measurements of the magnetic susceptibility (MS) in sedimentary sequences can quickly provide information on the variability of their mineral composition. A typical application of MS is the reconstruction of the supply of terrigenous material in car¬bonate rocks or the variability of the ratio of ferromagnetic to paramagnetic /diamagnetic minerals in clastic rocks. The article discusses the practical aspects of using the Bartington's portable apparatus for magnetic susceptibility probing along with the correlation of these results with the mineral composition obtained from X-ray diffraction tests. The analysed rock material was red and green clays from the vicinity of Częstochowa, assigned to the mud-evaporite Ozimek Member, Grabowa Formation (Keuper facies, Upper Triassic). The obtained results indicate the possibility of a correlation between the MS and the composition of rock-forming minerals in the studied sediments, where in green clays the magnetite/maghemite with pyrrhotite(?) does not substantially affect the MS, and para- and/or diamagnetic minerals have a decisive role. In the red clays the dominant MS carrier is the hematite.
EN
This paper presents a structural analysis of various methods to produce bacterial cellulose (BC) from Nata de Coco (Acetobacter xylinum). BC sheet, BC chem and BC mech powders were successfully prepared using oven drying, chemical and mechanical treatment. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM) were used to analyze the structure of prepared BC. The structure of bacterial cellulose was compared with the structure of commercial microcrystalline cellulose (MCC) and cotton fabric. The XRD results showed that the BC sheet sample had the highest degree of crystallinity (81.76%) compared to cotton cellulose (75.73%). The crystallite size of cotton was larger than the BC sheet, with the value of 6.83 ηm and 4.55 ηm, respectively. The peaks in the FTIR spectra of all BC were comparable to the commercial MCC and cotton fabrics. FESEM images showed that the prepared BC sheet, BC mech, and BC chem had an almost similar structure like commercial MCC and cotton fabric. It was concluded that simple preparation of BC could be implemented and used for further BC preparation as reinforcement in polymer composites, especially in food packaging.
PL
Niniejszy artykuł zawiera analizę struktury celulozy bakteryjnej (BC) wytworzonej z Nata de Coco (Acetobacter xylinum) różnymi metodami. Folia BC i proszki BC chem oraz BC mech zo -stały wytworzone poprzez suszenie w piecu, obróbkę chemiczną i mechaniczną. Do oceny struktury celulozy bakteryjnej stosowano dyfrakcję rentgenowską (XRD), spektroskopię Fouriera w podczerwieni (FTIR) i skaningową mikroskopię elektronową z emisją polową (FESEM). Strukturę celulozy bakteryjnej porównano ze strukturą handlowej celulozy mikrokrystalicznej (MCC) i tkaniny bawełnianej. Wyniki XRD wykazały, że najwyższy stopień krystaliczności miała próbka arkusza BC (81,76%) w porównaniu z celulozą bawełnianą (75,73%). Wielkość krystalitów bawełny była większa niż folii BC i wynosiła, odpowiednio, 6,83 ηm oraz 4,55 ηm. Piki widm FTIR wszystkich otrzymanych form celulozy bakteryjnej były porównywalne z komercyjnymi tkaninami bawełnianymi i z celulozy mikrokrystalicznej. Zdjęcia FESEM folii BC oraz proszków BC mech i BC chem również były podobne do komercyjnej MCC i tkaniny bawełnianej. Stwierdzono, że z wykorzystaniem prostych technik można otrzymać BC, która może być stosowana jako wzmocnienie w kompozytach polimerowych, w szczególności w opakowaniach do żywności.
EN
High molecular weight chitosan was synthesized from shrimp shells. Chemical structure of chitosan was confirmed using FT-IR, XRD, TGA, and SEM analyses. Physicochemical properties of chitosan such as molecular weight (800 000 g/mol), deacetylation degree (80%), ash content (1%) indicating effectiveness of demineralization step in removing minerals, water binding capacity (4220%), and fat binding capacity (537%), were determined. FT-IR spectra exhibited characteristic joint band at 3365 cm-1 due to –OH and –NH2 regarding to the conversion of chitin acetyl group to NH2 of chitosan.
PL
Z muszli krewetek zsyntetyzowano chitozan o wysokiej masie cząsteczkowej. Strukturę chemiczną chitozanu potwierdzono metodami FT-IR, XRD, TGA i SEM. Określono właściwości fizykochemiczne chitozanu takie jak masa cząsteczkowa (800 000 g/mol), stopień deacetylacji (80%), wskazu jącą na skuteczność procesu demineralizacji zawartość popiołów (1%), zdolność wiązania wody (4220%) i zdolność wiązania tłuszczu (537%). Widma FT-IR wykazały charakterystyczne pasmo przy liczbie falowej 3365 cm-1, pochodzące od grup –OH i–NH2, wynikające z przekształcenia grupy acetylowej chityny w NH2 chitozanu.
EN
Focus of the current study is to shed more light on thermal behaviour of composites made up of areca sheath fibres. The XRD analysis revealed that crystallinity index and crystallinity percentage increased with different treatments, as it leads to better interaction of fibre and resin. The crystallinity percentage of alkali treated fibre and benzoyl peroxide treated fibre increased by 5.87 and 8.44% respectively compared to untreated fibre. This was further evident in thermal studies which proved better thermal stability in benzoyl peroxide treated fibre composite.
EN
Purpose: There are several advantages of using a biological technique to produce nanoparticles versus a chemical method. The primary goal of this work is to characterize and biologically synthesize titanium dioxide (TiO2) nanoparticles from Cynodon dactylon. The characterization has experimented with UV-Vis Spectroscopy, EDX analysis, SEM, XRD, and FTIR. Design/methodology/approach: The suggested study uses a simple biological technique to accomplish the systematic biological synthesis of TiO2 nanoparticles utilizing Cynodon dactylon plant extract and titanium tetra isopropoxide as a precursor. UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-Ray Diffraction (XRD) are used to confirm the fabrication of the TiO2 nanoparticles. The plant extract as well as titanium-based nanoparticles of the herb, Cynodon dactylon will be tested for its antibacterial activity against human pathogens. This eco-friendly technique for nanoparticle synthesis is straightforward and adaptable to major commercial manufacturing and technological applications. Findings: Cynodon dactylon biosynthesis of TiO2 nanoparticles is efficient, nutrition dependent, does not employ hazardous compounds, and happens at neutral pH levels. The antibacterial study results show that TiO2 nanoparticles synthesized using Cynodon dactylon have good antibacterial properties. TiO2 nanoparticle method of action against bacteria is unknown. This is an alternative process for synthesising TiO2 nanoparticles, apart from other chemical protocols, since this is quick and non-toxic. The antimicrobial property of biologically synthesized TiO2 nanoparticles against Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii was tested at four different doses of 15 μl/mg, 25 μl/mg, 50 μl/mg, and 75 μl/mg. The present results revealed the 75 μl/mg concentration got the highest zone of inhibition (15, 13, 15 mm) for Acinetobacter baumannii, Staphylococcus aureus, and Escherichia coli. Research limitations/implications: Many nanoparticles smaller than 100 nm are firmly agglomerated with each other in the study. TiO2 nanoparticles absorb in the UV region of 200 to 400 nm. XRD measurements confirmed the presence of TiO2 nanoparticles in the biologically produced sample. In our work, EDX was used to confirm the existence of Ti after its synthesis by Cynodon dactylon. Practical implications: The biosynthesized TiO2 nanoparticles utilizing Cynodon dactylon plant extracts exhibit a good potent antibacterial activity. The proposed results showed that the TiO2 nanoparticles are well suited for biomedical applications. Originality/value: The suggested research identifies several eco-friendly, biological, and cost-effective procedures for manufacturing nano-coated herbal products. The agar well diffusion technique was used to assess antibacterial activities toward test pathogens such as Acinetobacter baumannii, Staphylococcus aureus, and Escherichia coli.
EN
In order to improve the utilization rate of coal resources, it is necessary to classify coal and gangue, but the classification of coal is particularly important. Nevertheless, the current coal and gangue sorting technology mainly focus on the identification of coal and gangue, and no in-depth research has been carried out on the identification of coal species. Accordingly, in order to preliminary screen coal types, this paper proposed a method to predict the coal metamorphic degree while identifying coal and gangue based on Energy Dispersive X-Ray Diffraction (EDXRD) principle with 1/3 coking coal, gas coal, and gangue from Huainan mine, China as the research object. Differences in the phase composition of 1/3 coking coal, gas coal, and gangue were analyzed by combining the EDXRD patterns with the Angle Dispersive X-Ray Diffraction (ADXRD) patterns. The calculation method for characterizing the metamorphism degree of coal by EDXRD patterns was investigated, and then a PSO-SVM model for the classification of coal and gangue and the prediction of coal metamorphism degree was developed. Based on the results, it is shown that by embedding the calculation method of coal metamorphism degree into the coal and gangue identification model, the PSO-SVM model can identify coal and gangue and also output the metamorphism degree of coal, which in turn achieves the purpose of preliminary screening of coal types. As such, the method provides a new way of thinking and theoretical reference for coal and gangue identification.
PL
W celu poprawy stopnia wykorzystania zasobów węgla konieczna jest klasyfikacja węgla i skały płonnej, ale to klasyfikacja węgla jest szczególnie ważna. Niemniej jednak obecna technologia separacji węgla i skały płonnej koncentruje się głównie na identyfikacji węgla i skały płonnej, ale nie przeprowadzono dogłębnych badań dotyczących identyfikacji gatunków węgla. W związku z tym, w celu wstępnego przesiewu rodzajów węgla, w niniejszym artykule zaproponowano metodę przewidywania stopnia metamorfizmu węgla przy identyfikacji węgla i skały płonnej w oparciu o zasadę dyfrakcji rentgenowskiej z dyspersją energii (EDXRD) z 1/3 węglem koksującym, węglem gazowym i skałą płonną z kopalni Huainan w Chinach jako obiektem badawczym. Różnice w składzie fazowym 1/3 węgla koksowego, węgla gazowego i skały płonnej analizowano przez połączenie wzorców EDXRD z wzorcami dyfrakcji rentgenowskiej z dyspersją kątową (ADXRD). Zbadano metodę obliczeniową charakteryzującą stopień metamorfizmu węgla za pomocą wzorców EDXRD, a następnie opracowano model PSO-SVM do klasyfikacji węgla i skały płonnej oraz przewidywania stopnia metamorfizmu węgla. Na podstawie uzyskanych wyników wykazano, że poprzez wbudowanie metody obliczania stopnia metamorfizmu węgla w model identyfikacji węgla i skały płonnej, model PSO-SVM może identyfikować węgiel i skałę płonną, a także wyprowadzać stopień metamorfizmu węgla, co z kolei spełnia cel wstępnego przesiewania rodzajów węgla. Jako taka, metoda ta zapewnia nowy sposób myślenia i teoretyczne odniesienie do identyfikacji węgla i skał płonnych.
EN
This study evaluated the structural changes of Al-Ni-(Fe,Cr,Cu)-Y alloys induced by different cooling states. The aim was to determine the role of Fe, Cr, and Cu addition as well as cooling rate on the structure, hardness and anticorrosion properties of crystalline and nanocrystalline Al-Ni-Y alloys. The impact of the preparation method on the structure of alloys was observed by the broadening of the X-ray diffraction peaks of the alloys in the form of plates, which indicated structure fragmentation at a high cooling rate. The TEM images showed the formation of a structure composed of homogeneously dispersed α-Al nanograins. Phase analysis performed using X-ray diffraction method and Mossbauer spectroscopy revealed that the slowly cooled master alloys were mainly composed of Al23Ni6Y4, Al10Fe2Y, and α-Al phases. The Al10Fe2Y structure was the main Fe-bearing phase in all investigated master alloys. A crystallization mechanism was proposed based on the DTA heating and cooling curves. The pitting corrosion type was identified based on morphology observations after electrochemical tests. Rapid solidification and the addition of chromium and copper improved the microhardness as well as corrosion resistance. The high increase of hardness (289 HV0.1) and corrosion resistance[...]
PL
W pracy przedstawiono badania odpowiednie do wytworzenia głównego składnika cementu portlandzkiego − krzemianu trójwapnia. Przeprowadzone badania obejmowały ujednorodnienie zestawu, ocenę stałości jego składu z wykorzystaniem rentgenowskiej analizy fazowej w połączeniu z metodą Rietvelda oraz wyniki XRD wytworzonego spieku. Zaprezentowane wyniki potwierdzają adekwatność przyjętych metod badawczych do wytworzenia jednorodnego spieku zawierającego alit (krzemian trójwapnia).
EN
The paper presents tests suitable for the production of the main component of Portland cement - tricalcium silicate. The tests carried out included homogenization of the batch of raw material sets, assessment of the constancy of its composition with the use of X-ray phase analysis in conjunction with the analysis of the results using the Rietveld method, and the XRD results of the sinter produced. The presented results confirm the adequacy of the adopted research methods for the production of a homogeneous sintered alite (tricalcium silicate).
EN
Some phosphate sludges (Ps) were collected in 2009, 2014, and 2018. Results of their analyses by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM-SED), differential thermal and thermogravimetric analyses (TG-DTA) and X-ray fluorescence spectrometry (XRF) confirmed that the Ps are highly carbonated. Descriptive and exploratory statistical procedures for heavy metals (HM) concentrations and chemical parameters were performed and revealed the differences between the Ps of three different ages. The results indicate that there are three sources responsible for the behavior of Ps over years: common origin and accumulation of HIM and solar radiation exposure. The sequential extraction shows that the residual fractions of Cd, Ni, Zn, Pb, and Cr were predominant The mobility factor was quite low and did not change over the years, except for Cd. The net acid generation pH for the three samples was greater than 4.5 classifying the Ps as non-acid-generating.
EN
Selective laser melted Titanium grade 23 was characterized by low porosity, relatively large surface roughness and pronounced surface texture (i.e. surface grooves orientation). The band/layer microstructure was built of mixed α and β phases. The as printed structure exhibited very high compressive residual stresses with strong anisotropy (i.e., − 512 ± 17 MPa and − 282 ± 14 MPa along the laser scanning direction and along the transverse direction, respectively) and strong fiber crystallographic texture. The latter one is responsible for the anisotropy of hardness in the material. Annealing at 600 °C during four hours significantly removed residual stresses (i.e. to − 14 ± 2.8 MPa) and slightly weakened the texture. Yield strength, 1120 ± 50 MPa, and ultimate tensile strength, 1210 ± 50 MPa, of the annealed material are significantly higher and tensile elongation, 3.9%, lower than for commercial Titanium grade 23. Final mechanical polishing to obtain flat and relatively smooth surface induced desired compression residual stress in the subsurface (i.e., equal to about − 90 MPa). Low absorbed gas contents (oxygen, nitrogen, hydrogen) and low porosity of the printed material indicates the correctness of the technology and allows the printed material to be classified as meeting the requirements of ASTM standards for Titanium grade 23. Besides traditional testing techniques, the optical profilometry, X-ray analysis (texture and residual stresses measurement) and infrared absorption method were applied for the product characterization and some potential of these testing methods and usefulness in technological practice was discussed, what can be particularly interesting both to practitioners from industry and researches from scientific laboratories.
PL
Koła zębate przekładni lotniczych cechuje wysoki współczynnik niezawodności, wymagany ze względu na obszar zastosowania, dynamiczny charakter pracy oraz przenoszoną moc. Podczas całego cyklu eksploatacyjnego powierzchnie boczne zębów oraz obszary ich podstaw są narażone na uszkodzenia związane z różnymi stanami naprężeń występującymi w czasie zazębienia oraz okresie, kiedy poszczególne zęby kół współpracujących nie stykają się ze sobą. Koncentracja tych naprężeń, związana m.in. z dokładnością wykonania zębów, może prowadzić do różnego typu defektów, takich jak: „pitting”, zgniot, złom, uszkodzenia interferencyjne, wytarcia, wydarcia, odpryski, zatarcia czy przegrzania. W związku z tym koła zębate są poddawane m.in. badaniom naprężeń własnych metodą dyfrakcji rentgenowskiej, dla której procedura wykonania pomiarów oraz przygotowania materiału badawczego jest problematyczna ze względu na ograniczony lub niemożliwy bezpośredni dostęp do wymaganych obszarów pomiarowych. W niniejszym artykule opisano dwie metody przygotowania próbek do badań naprężeń własnych z zastosowaniem dyfraktometru rentgenowskiego wyposażonego w lampę chromową. Zakresem badań objęto: polerowanie elektrolityczne oraz cięcie elektroerozyjne. Przygotowane próbki kół zębatych, reprezentujące rozważane metody, poddano serii pomiarów na stanowisku badawczym, a otrzymane wartości naprężeń, reprezentujące ich stany w warstwie wierzchniej, poddano analizie. Porównano wpływ obydwu metod przygotowania kół zębatych na wartość naprężeń własnych warstwy wierzchniej zębów koła zębatego oraz wykazano, że rodzaj obróbki stosowanej podczas przygotowania próbek ma wpływ na wartości pomiarów naprężeń własnych.
EN
Delafossite AgFeO2, AgFe0.9Al0.1O2, AgFe0.9Ni0.1O2, and AgFe0.9Co0.1O2 powders were synthesized by hydrothermal method. The structural analysis and hyperfine interactions investigations were performed by X-ray diffraction and the Mössbauer spectroscopy. It was found that the (Al, Ni, Co)-doped delafossite phases with traces of metallic silver can be obtained during hydrothermal synthesis. Investigations revealed that the type of the incorporated element has an impact on the structural properties of the obtained delafossites. However, doping of cobalt, nickel, and alumina ions to the AgFeO2 delafossite structure does not cause significant changes in the values of the hyperfine interactions parameters. The of the Mössbauer spectra confirm the paramagnetic character of the obtained compounds at room temperature.
PL
Proszkowe próbki delafosytów AgFeO2, AgFe0.9Al0.1O2, AgFe0.9Ni0.1O2, and AgFe0.9Co0.1O2 zostały wytworzone metodą hydrotermalną. Badania pozwalające na analizę strukturalną oraz oszacowanie parametrów oddziaływań nadsubtelnych przeprowadzono z wykorzystaniem dyfrakcji rentgenowskiej oraz spektroskopii efektu Mössbauera. Udowodniono, że za pomocą metody hydrotermalnej istnieje możliwość wytworzenia delafosytu AgFeO2 domieszkowanego jonami glinu, niklu i kobaltu z niewielką ilością zanieczyszczeń metalicznym srebrem. Badania wykazały, że rodzaj domieszki ma wpływ na właściwości strukturalne otrzymanych materiałów. Domieszkowanie jednak nie wpłynęło znacząco na zmiany wartości parametrów oddziaływań nadsubtelnych. Kształt zarejestrowanych widm mössbauerowskich potwierdza paramagnetyzm otrzymanych materiałów w temperaturze pokojowej.
EN
This research work discusses both the physical and durability characteristics of newly blended cement containing waste crushed brick. This waste is used as a partial substitution for clinker in cement. Thus, blended cements are obtained by grinding and homogenizing clinker, waste brick, and gypsum. Four compositions containing 0%, 10%, 20%, and 30% of waste materials were prepared and submitted to various characterization tests. The introduction of brick powder improved the physical characteristics, therefore; it improved the mechanical properties and durability performance of the new cement compared to the reference, prepared with 0% addition. More particularly, it resisted sulfuric acid (H2SO4) attack after fixation of portlandite by pozzolan.
EN
Perovskite is able to sequester simultaneously, in its structure, both actinides and alkaline-earth elements. This study is an attempt to synthesize a complex perovskite Ca0.91-xCe0.09Rb0.04Csx [(Zr0.50Ti0.45)Al0.05]O3 (0.2≤x≤0.4), doped in the same time, with Ce, Cs and Rb. The synthesis is conducted by sintering at 1150°C during 16h. XRX analysis confirms the perovskite formation. SEM observations show a less porous microstructure. FTIR analysis reveals TiO6, Ti-O-Ti, Ti-O and Zr-O vibrations. Raman spectroscopy indicates many orthorhombic perovskite active modes, as: Ti-O6 and Ti-O3 torsions, ZrO7, CaO8 vibrations, the totally symmetric oxygen, and the O-octahedron cage rotation.
EN
In this study, the effects of using different ratios of fly ash on hydration products as well as the mechanical and microstructural properties of hardened concrete were investigated. Portland cement was replaced with 5%, 10%, 15% and 20% fly ash (FA) by weight. The microstructural properties of the obtained samples were investigated by means of X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Fly ash has negative effect on 7 days concrete strength; however, it was seen that fly ash increases the compressive strength of 28 and 90 days concrete. The XRD analysis showed that the ratio of calcium hydroxide (CH), which is produced by hydration, decreases depending on the concrete age and the amount of fly ash. The SEM analysis showed that the usage of fly ash decreases gaps and increases C-S-H which is also a hydration production. When Portland cement was replaced with 10% fly ash by weight, compressive strength has increased and microstructure of concrete has improved. The reason for this is filling of gaps by fly ash and the decrease in the amount of Ca(OH)2 due to the reaction between fly ash and Ca(OH)2. Within this scope, the development in microstructure of fly ash concrete was evaluated in 90 days duration and a change of the development with compressive strength was investigated.
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PL
W artykule scharakteryzowano strefę graniczną połączenia Hastelloy X – Palnicro 36M, w której oddziaływały bezpośrednio ciekły lut z materiałem podłoża w stanie stałym. Głównym celem prowadzonych badań była analiza mikrostruktury strefy granicznej oraz identyfikacja występujących w niej faz. W badaniach wykorzystano mikroskopie świetlną, skaningową mikroskopie elektronową (SEM) wraz z analizą EDS oraz metodę dyfrakcji rentgenowskiej (XRD). W strefie granicznej zidentyfikowano fazy tworzone przez: molibden nikiel (Mo1,08Ni2,92), tetrataenite NiFe, chrom nikiel (CrNi), bor chrom Cr5B3. Badania wskazały również na możliwość występowania w strefie granicznej faz na bazie związków międzymetalicznych Cr3NiB6 i Mo6(Ni0,75Si0,25)7.
EN
The article describes boundary zone for the Hastelloy X - Palnicro 36M brazed joint, in which liquid brazing filler metal interacted directly with solid base metal. The main objective of the research was to analyze the microstructure of the border zone and to recognize the occurring phases. Methods used in the research were light microscopy, scanning electron microscopy (SEM) with EDS analysis and X-ray diffraction (XRD). In the phase boundary zone the following phases were identified: molybdenum nickel (Mo1,08Ni2,92), tetrataenite NiFe, chromium nickel (CrNi), baron chromium Cr5B3. Studies have also indicated the possibility of occurrence of phases based on Cr3NiB6 and Mo6(Ni0,75Si0,25)7 intermetallic compound in the phase boundary zone.
EN
The paper presents the results of research on the structure and selected properties of magnetic alloys based on Fe. The alloy with the chemical composition Fe36Co36Y8B20 was produced using two methods: forcing and sucking the liquid alloy into a copper mould. The alloy was cast in the form of 10 mm × 5 mm × 0.5 mm tiles. The structure of the obtained alloys was examined using X-ray diffraction. The measured diffractograms are typical for amorphous materials. Using the Faraday magnetic balance, the magnetic saturation polarisation curves as a function of temperature were recorded. The Curie temperature of the created alloys, which amounted to approximately 750 K, was determined on the basis of numerical analysis. The original magnetisation curves and static magnetic hysteresis loops were measured using a vibration magnetometer. The produced alloys had a saturation magnetisation of about 1.1T and a coercive field value of about 200 A/m. The curves of primary magnetisation were analysed using H. Kronmüller’s theory. It was found that the magnetising process in the area called the ‘approach to ferromagnetic saturation’ is related to the rotation of the magnetisation vector around the linear defects of the structure.
PL
W pracy zamieszczono wyniki badań struktury i wybranych właściwości magnetycznych stopów na bazie Fe. Stop o składzie chemicznym Fe36Co36Y8B20 wytworzono dwiema metodami: wtłaczania oraz zasysania ciekłego stopu do miedzianej formy. Stop odlewano w postaci płytek o wymiarach 10 mm × 5 mm × 0,5 mm. Strukturę otrzymanych stopów badano przy użyciu dyfrakcji rentgenowskiej. Zmierzone dyfraktogramy są typowe jak dla materiałów amorficznych. Przy użyciu wagi magnetycznej Faraday’a zarejestrowano krzywe magnetycznej polaryzacji nasycenia w funkcji temperatury. Na podstawie analizy numerycznej krzywych wyznaczono temperaturę Curie wytworzonych stopów, która wyniosła około 750 K. Przy użyciu magnetometru wibracyjnego zmierzono pierwotne krzywe magnesowania oraz statyczne pętle histerezy magnetycznej. Wytworzone stopy posiadały magnetyzację nasycenia około 1,1T oraz wartość pola koercji około 200 A/m. Wykorzystując teorię H. Kronmüllera, przeprowadzono analizę krzywych pierwotnego magnesowania. Stwierdzono, że proces magnesowania w obszarze zwanym podejściem do ferromagnetycznego nasycenia związany jest z obrotem wektora magnetyzacji wokół liniowych defektów struktury.
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