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  1. 11 Inżynieria Materiałowa
  2. 11 Materials Engineering
  3. 7 Journal of Achievements in Materials and Manufacturing Engineering
  4. 4 Materials Science Poland
  5. 3 Analityka : nauka i praktyka
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  1. 3 Dobrzański L. A.
  2. 2 Domagała J.
  3. 2 Donten M.
  4. 2 Klimek L.
  5. 2 Szindler M.
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  1. 4 2024
  2. 1 2023
  3. 5 2022
  4. 1 2021
  5. 3 2020
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1
Content available Badania zmian w strukturze płyt włóknisto-cementowych poddanych oddziaływaniom wybranych czynników eksploatacyjnych
Gorzelańczyk Tomasz
Przegląd Budowlany
|
2024
|
R. 95, nr 3
110--115
PL
W artykule przedstawiono wyniki badań wpływu zamrażania-rozmrażania oraz naświetlania promieniowaniem UV w komorze starzeniowej na strukturę płyt włóknisto-cementowych. W celu wykazania wpływu wyżej wymienionych czynników płyty w pierwszej kolejności przebadano z wykorzystaniem metody emisji akustycznej w próbie trójpunktowego zginania. Badania te wykazały wyraźny spadek liczby zarejestrowanych zdarzeń EA dla badanych płyt, szczególnie dla tych, które były poddane oddziaływaniu cykli zamrażania-rozmrażania w porównaniu z płytami referencyjnymi. Następnie w celu dokładniejszego zobrazowania zmian zachodzących w strukturze badanych płyt przeprowadzono badania z wykorzystaniem elektronowego mikroskopu skaningowego SEM.
EN
The article presents the results of research on the effect of cyclic freeze-thaw and UV irradiation on the structure of fibre-cement boards in an aging chamber. In order to demonstrate the impact of the above-mentioned factors, the panels were first tested using the acoustic emission method in the three-point bending test. These studies showed a clear decrease in the number of recorded EA events for the tested boards, especially for those that were subjected to freeze-thaw cycles compared to the reference boards. Then, in order to more accurately illustrate the changes occurring in the structure of the tested boards, tests were carried out using a scanning electron microscope (SEM).
2
Content available remote Effects of infill density on mechanical properties of additively manufactured chopped carbon fiber reinforced PLA composites
Mayandi K., Rigesh K., Nagarajan Rajini, Ismail Sikiru O., Krishnan Kumar, Mohammad Faruq, Al-Lohedan Hamad A.
Materials Science Poland
|
2024
|
Vol. 42, No. 1
42--51
EN
In this present study, the fused deposition modeling (FDM) method was used to fabricate the composites. Before three-dimensional (3D) printing, samples were designed according to the ASTM D256, D790 and D3039 standards for impact, flexural and tensile tests, respectively, using Onshape software before conversion to an STL file format. Afterward, the digital file was sliced with infill densities of 60%, 80%, and 100%. The composite samples contained chopped carbon fiber (cCF) and poly lactic acid (PLA), as reinforcement and matrix, respectively. The cCF/PLA (simply called cCFP) filaments were printed into various cCFP composite (cCFPC) samples, using a Viper Share bot 3D machine with different infill densities before the aforementioned mechanical testing. The tensile strength of cCFP were obtained as 25.9MPa, 26.9MPa and 34.75MPa for 60%, 80% and 100% infill density cCFP samples, respectively. Similarly, the flexural strength of cCFP were obtained as 11.8MPa, 12.55MPa and 18.4MPa and impact strength was 47.48kJ/m2, 48.45kJ/m22 for 60%, 80% and 100% infill density cCFP samples, respectively. The fractured/tested samples were examined and analyzed under a scanning electron microscope (SEM) to investigate the presence of fiber and void in the tensile sample. Based on the experimental results, it was evident that a high infill density of 100% with the highest reinforcement exhibited maximum impact strength, tensile and flexural strengths and moduli when compared with other lower carbon content of cCFPC samples. Therefore, the optimal 3D-printed cCFPC sample could be used for engineering application to benefit from properties of the polymer matrix composite materials and possibilities through additive manufacturing (AM).
3
Content available remote Effect of TiC and BN nanoparticles on mechanical and microstructural characteristics of Al7085 hybrid nanocomposites
Garapati Prem Kumar, Dumpala Lingaraju, Rao Y Seetha Rama
Composites Theory and Practice
|
2024
|
R. 24, nr 1
57--64
EN
This study regards investigations of the mechanical properties of aluminum 7085/TiC/BN hybrid metal matrix nanocomposites (HMMNCs). The ultrasonic assisted stir casting (UASC) route was used to manufacture the Al7085 HMMNCs by varying the wt.% of titanium carbide (TiC) and boron nitride (BN) (0.0, 0.5, 1.0, 1.5, and 2.0). By means of scanning electron microscopy (SEM) it was observed that the nanoparticles are evenly distributed in the nanocomposites. Additionally, the EDS and XRD results indicate that there were no signs of oxide formations, secondary phases, or impurities in the nanocomposites. The yield tensile strength (YTS), ultimate tensile strength (UTS) and microhardness of the nanocomposites improved with increases in the wt.% of TiC and BN particles up to 1.5, and thereafter decreased. The % elongation of the nanocomposites was reduced and the density of the nanocomposites improved with the addition of TiC and BN nanoparticles.
4
Content available remote Experimental investigation on corrosion behaviour of heat-treated API X70 pipeline steel
Sharma Lochan, Dhiman Anurag, Jakhar Amman, Sharma Kanika
Advances in Materials Science
|
2024
|
Vol. 24, nr 2(80)
70--91
EN
In present study mass loss behaviour of base metal and heat-treated API X70 pipeline steel in different environments such as fresh water, sea water and sodium thiosulphate medium were observed for 50 days. Corrosion is the main failure in pipeline steel which need to be reduced with the use of suitable heat treatment process. In present study two heat treatment such as HT-1 900 ̊C (2 hour) with tempering at 450 ̊C (4 hour) and HT-2 800 ̊C (2 hour) with tempering at 450 ̊C (4 hour) was used. Mechanical, microstructure and corrosion rate of HT-1 and HT-2 specimen in different environments were observed. Maximum corrosion rate (0.306 mm/y) in fresh water while minimum corrosion rate (0.181 mm/y) in sodium thiosulphate medium was observed for base metal. Maximum corrosion rate (0.224 mm/y) in sodium thiosulphate while minimum corrosion rate (0.106 mm/y) in fresh water medium was observed for HT-1 specimen. For HT-2 specimen, Maximum corrosion rate (0.192 mm/y) in sea water while minimum corrosion rate (0.099 mm/y) in fresh water medium was observed. For HT-2 specimen, maximum average hardness of (30.3 HRC) in sea water while minimum average hardness of (28 HRC) of base metal was observed. In fresh water also HT-2 specimen, maximum average hardness is (26.3 HRC) while minimum average hardness of (24.6 HRC) of base metal was observed. After that maximum average hardness of base metal (26.6 HRC) in sodium thiosulphate while minimum average hardness of (21 HRC) of HT-2 specimen was observed.
5
Content available Evolution and Characterization of Zirconium 702 alloy at various temperatures
Lade Jayahari, Dharavath Baloji, Badrish Anand, Kosaraju Satyanarayana, Singh Swadesh Kumar, Saxena Kuldeep Kumar
Archives of Metallurgy and Materials
|
2023
|
Vol. 68, iss. 2
807--812
EN
The Zirconium 702 alloy effectively used in nuclear industry at various critical conditions like high temperature and high pressure. This survey is an assessment of insights into the mechanical properties of the metal when exposed to different temperatures along the rolling direction.The main objective of this work is to characterize the tensile properties, and fracture study of broken tensile test samples at various temperatures.The tensile samples tested in our current work are 100°C, 150°C, and 200°C temperatures in different directions (0°, 45°, 90°) along with the rolling direction of the sheet. It is evident from the experimental results that temperatures significantly affect material properties. Temperature increases cause % elongation to increase, and strength decreases. ANOVA analysis revealed that temperature significantly influenced ultimate tensile strength (UTS), and yield strength (YS), as well as % elongation.The temperature contribution for UTS, YS, and % elongation is 41.90%, 31.60%, and 77.80% respectively. SEM fractured images showing the ductile type of behavior for all the temperatures.
6
Content available remote Study on the effect of nanosilica suspension on the properties of cement-based grouts
Li Shuiping, Chao Wei, Li Wei, Cheng Jian, Yuan Bin
Materials Science Poland
|
2022
|
Vol. 40, No. 4
171--182
EN
The agglomeration trend of nanosilica particles was found to significantly affect the properties of cement-based materials. The influence of nanosilica suspension on the fluidity, setting time, and compressive strength of cement-based grouts were studied. The hardened pastes were characterized by thermogravimetric (TG) analysis and scanning electron microscopy (SEM). The results showed that the fluidity of cement-based grouts with nanosilica suspension had obviously improved. The setting time was obviously decreased, compared with the reference sample. The compressive strengths for 1 day, 3 days, and 28 days were 12.8%, 14.3%, and 10.1% higher than that of the reference group, respectively. This paper may provide a novel route to improve the mechanical properties of cement-based materials without affecting their workability.
7
Content available The modern approach to manufacturing of carbon-rhenium nanocomposites
Dobrzańska-Danikiewicz A. D., Wolany W.
Journal of Achievements in Materials and Manufacturing Engineering
|
2022
|
Vol. 115, nr 2
57--63
EN
Purpose: The aim of the paper is to present the high-temperature method of producing MWCNTs-Re nanocomposites, the selection of satisfactory production conditions and the presentation of the results of microscopic and spectroscopic studies of nanocomposites produced by this method. Design/methodology/approach: Two methods of manufacturing carbon-rhenium nanocomposites were tested: ineffective chemical synthesis and high-temperature reduction using H2, which was proven successful and allowed the production of nanocomposites with the expected properties. The received nanocomposites were investigated using Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM), as well as were subjected to spectroscopic examination. Findings: The article presents three steps of MWCNTs-Re nanocomposites fabrication using the high-temperature method, functionalization, impregnation and reduction. As part of own work, satisfactory conditions for producing those nanocomposites using a materials science and heuristic analysis were selected. Research limitations/implications: The proposed high-temperature method allows to join rhenium nanoparticles with MWCNTs permanently. It is reasonable to test in the future whether the method is also effective for other carbon nanomaterials and/or nanoparticles of other metals. Practical implications: MWCNTs-Re nanocomposites can be used as sensors of gases that are harmful to the environment. It was also confirmed that the MWCNTs-Re_4 nanocomposite has catalytic properties. Originality/value: The paper presents a modern approach to the manufacturing of MWCNTs-Re nanocomposites, which assumes the use of a high-temperature furnace to heat the material in a hydrogen atmosphere.
8
Charakteryzacja morfologii powierzchni warstwy fotoanody oraz warstwy kropek kwantowych na podłożu porowatym w ogniwach fotowoltaicznych III generacji
Kwaśnicki Paweł, Grąz Katarzyna, Gronba-Chyła Anna
Inżynieria Materiałowa
|
2022
|
Vol. 43, nr 3
9--13
PL
W pracy przedstawiono wyniki badań mających na celu określenie stopnia upakowania struktur niskowymiarowych w postaci kropek kwantowych (QDs) dla podłoży mezoporowatych. Wykorzystanie kropek kwantowych w fotowoltaice pozwala na poprawę efektywności konwersji oraz poszerzenie spektrum absorpcyjnego. Wyzwaniem technologicznym jest zarówno proces depozycji QDs, jak i znalezienie odpowiedniej metody określenia kluczowych parametrów, w tym stopnia upakowania, jednorodności rozmieszczenia QDs czy ich parametrów przestrzennych. W pracy przedstawiono wyniki badań z wykorzystaniem skaningowej mikroskopii elektronowej oraz pomiarów przy użyciu spektroskopii Ramana.
EN
This paper presents the results of a study to determine the packing of low-dimensional structures in the form of quantum dots (QDs) for mesoporous substrates. The use of quantum dots in photovoltaics allows for improved conversion efficiency and broadening of the absorption spectrum. The technological challenge is both the deposition process of the QDs and finding a suitable method to determine key parameters including the degree of packing, homogeneity of QDs distribution or their spatial parameters. In this paper, results from scanning electron microscopy and measurements using Raman spectroscopy are presented.
9
Content available SEM Automated Mineralogy applied for the quantification of mineral and textural sorting in submarine sediment gravity flows
Pszonka Joanna, Schulz Bernhard
Gospodarka Surowcami Mineralnymi
|
2022
|
T. 38, z. 4
105--131
EN
SEM Automated Mineralogy (SEM-AM) is an analytical system based on a scanning electron microscope (SEM) with backscattered electron detector and an energy dispersive X-ray spectrometer (EDS). This automated tool enables to quantify mineralogy, size and geometry of solid matter components. The paper presents a SEM-AM application in detection of mineralogical and textural sediment sorting on the example of a submarine gravity flow record from the Cergowa sandstones (Lower Oligocene) in the Polish Outer Carpathians. Analysis of high quality backscattered electron (BSE) imagery in combination with EDX spectra discriminates mineral phases in polished samples. These data are then processed by the mineral liberation analysis (MLA) software in order to extract size and shape information, and combine, compare and group components for further examination. Automated data extraction provides highly representative measurement statistics devoid of manual work bias. The Cergowa sandstones were prepared for the analysis as non-granular samples in coated thin sections and granular samples in epoxy mounts. The former samples provide mineralogical data whereas the latter additionally generate textural parameters, both essential in interpretation of variability of flow competence. Comparisons between samples from an individual bed and between different beds of the measured sections give insights into the spatial and temporal flow development at a given locality. On the other hand, a comparison of different sections and regions of the formation will provide basis for the reconstruction of submarine flow events throughout the sedimentary basin and contribute to the characterisation of the provenance areas. Highly detailed quantitative data generated by this procedure have great potential in helping to recognise complex relationships between mineralogical and textural sorting by depositional processes.
PL
Zautomatyzowana mineralogia SEM jest analitycznym systemem bazującym na skaningowym mikroskopie elektronowym (SEM) wyposażonym w detektor elektronów wstecznie rozproszonych oraz spektrometr dyspersji energii (EDX). To zautomatyzowane narzędzie umożliwia kwantyfikację mineralogii, wielkości i geometrii komponentów ciał stałych. W artykule przedstawiono zastosowanie zautomatyzowanej mineralogii SEM w analizie mineralogicznego i teksturalnego sortowania osadów zdeponowanych przez podmorskie spływy grawitacyjne, na przykładzie piaskowców cergowskich (dolny oligocen) z polskich Karpat zewnętrznych. Analiza obrazów wysokiej rozdzielczości, generowanych przez elektrony wstecznie rozproszone (BSE), w połączeniu z zarejestrowanymi widmami EDX, pozwala określić fazy mineralne występujące w badanych próbkach. Te dane są następnie przetwarzane przez oprogramowanie Mineral Liberation Analysis (MLA) w celu ekstrakcji informacji o wielkości i kształcie komponentów, a także łączeniu, porównywaniu i grupowaniu wygenerowanych informacji do dalszych badań. Zautomatyzowana ekstrakcja danych dostarcza wysoce reprezentatywnych statystyk pomiarowych pozbawionych błędu pracy ręcznej. Piaskowce cergowskie zostały przygotowane do analizy jako zgłady w formie płytek cienkich oraz zatopione w żywicy wyseparowane ziarna. Pierwszy rodzaj próbek dostarcza danych o składzie mineralogicznym, natomiast drugi rodzaj dodatkowo pozwala wygenerować parametry teksturalne, oba istotne w interpretacji zmienności kompetencji podmorskich spływów grawitacyjnych. Porównania pomiędzy próbkami z tej samej warstwy oraz z różnych warstw profilu dają wgląd w przestrzenny i czasowy rozwój przepływu w danym miejscu. Natomiast porównanie próbek z różnych profilów i regionów formacji dostarcza informacji do rekonstrukcji podmorskich przepływów grawitacyjnych w basenie sedymentacyjnym i przyczynia się do charakterystyki obszarów proweniencji. Wysoko szczegółowe dane ilościowe generowane w MLA mają duży potencjał w rozpoznaniu złożonych zależności pomiędzy mineralogicznym i teksturalnym sortowaniem przez procesy depozycyjne.
10
Content available Mechanical properties and microstructure of alkali activated mortar containing unexpanded clay
Nasser I.F., Ali M.A., Kadhim M.J.
Archives of Materials Science and Engineering
|
2022
|
Vol. 113, nr 2
56--68
EN
Purpose: In building constructions, due to the decrease of local raw materials and for sustainability purpose, beside the need of light pieces to be used in roofing and false ceiling; an alkali-activated mortar is the new development where pozzolanic material is used instead of cement and activated by an alkaline solution. Therefore, in this research, alkali-activated mortar containing unexpanded clay as a fine aggregate with a dry density of 1652 kg/m3, compressive strength of 3.2 MPa, and thermal conductivity of 0.4 (W/m.K) was produced ,also boards were performed in a dimension of 305×152×12 mm as to use them in false ceiling, and reinforced with 0.25 and 0.5% steel fibre to improve their toughness by 370.8% and 1146.1% compared with reference boards, which made them good choice to used them in roofing and secondary ceiling. Design/methodology/approach: For preparation of alkali-activated mortar, low calcium fly ash (FA) was used as a source binder material. In addition, super-plasticizer and unexpanded clay as a fine aggregate (produce from the crushed artificial aggregate) in the ratio of 1:2.75 fly ash/fine aggregate. The paste was prepared by mixing fly ash with an alkali silicate solution, in a solid-to-liquid ratio of 0.4. Alkali silicate activator was prepared by mixing the NaOH and Na2SiO3 solutions at the mass ratios of 2.5. The concentrations of the NaOH was the same molarity of (14M).To improve the mechanical properties of the reference mortar mixture ,steel fibre with 0.25 and 0.5% content were added to the mix .The specimens were tested for water absorption, dry density, compressive strength, flexural strengths, flexural toughness, and thermal conductivity, in addition to the Scanning Electron Microscope test (SEM) for all mortar mixes. Alkali-activated mortar boards with (305×152×12 mm) were prepared and tested for flexural strength and toughness. Findings: The results indicated that the modulus of rupture for mortar boards reinforced with 0.25 and 0.5% steel fibre exhibits an increase of (3.68-12.10)%. In comparison, the toughness is increased by about 370.8% and 1146.1%, respectively, as compared with the reference mortar (without fibre) which made them resistance to accident, in addition to use them in roofing due to their thermal insulation. Research limitations/implications: Further research is needed to make a similar board using another sustainable material. We can examine the thermal insulation that we can get from these board, especially in the building in Iraq which the weather faces high temperatures. Practical implications: There is a by-product that we could get from the electricity station in Iraq. We must study how we get rid of it. Originality/value: This paper investigate how to produce a new light board using artificial aggregate made from unexpanded clay, which has many benefits in building insulation roofing.
11
Content available Crystallization of the Structural Components of Multiple Remelted AlSi9Cu3 Alloy
Matejka M., Bolibruchova D., Kuriš M.
Archives of Foundry Engineering
|
2021
|
Vol. 21, iss. 2
41--45
EN
At present, Al-Si-Cu based alloys (with a typical representative AlSi9Cu3 alloy) represent more than half of the castings used in various industries (automotive, aerospace and electrical engineering). These are most often sub-eutectic (exceptionally eutectic) alloys with a content of 6 to 13 wt. % Si and 1 to 5 wt. % Cu. The aim of the paper is to point out the importance of the evaluation of input raw materials that determines the overall properties of the casting and the costs invested in its production. A negative impact on performance can be expected when using an alloy made up of a high proportion of recycled material, despite its economic benefits. Experimental alloys were evaluated based on the results of crystallization process and a combination of scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and deep etching. The effect of remelting and increasing the remelted returnable material in the batch was manifested especially in the crystallization of iron-rich phases. The negative effect of remelting on the structural components was manifested after the fourth remelting. Gradual increase of remelted returnable material in the batch causes harmful changes in the crystallization process.
12
Content available A method of magnetic field measurement in a scanning electron microscope using a microcantilever magnetometer
Orłowska Karolina, Mognaschi Maria E., Kwoka Krzysztof, Piasecki Tomasz, Kunicki Piotr, Sierakowski Andrzej, Majstrzyk Wojciech, Podgórni Arkadiusz, Pruchnik Bartosz, di Barba Paolo, Gotszalk Teodor
Metrology and Measurement Systems
|
2020
|
Vol. 27, nr 1
141--149
EN
Scanning electron microscopy (SEM) is a perfect technique for micro-/nano-object imaging [1] and movement measurement [2, 3] both in high and environmental vacuum conditions and at various temperatures ranging from elevated to low temperatures. In our view, the magnetic field expanding from the pole-piece makes it possible to characterize the behaviour of electromagnetic micro- and nano-electromechanical systems (MEMS/NEMS) in which the deflection of the movable part is controlled by the electromagnetic force. What must be determined, however, is the magnetic field expanding from the e-beam column, which is a function of many factors, like working distance (WD), magnification and position of the device in relation to the e-beam column. There are only a few experimental methods for determination of the magnetic field in a scanning electron microscope. In this paper we present a method of the magnetic field determination under the scanning electron column by application of a silicon cantilever magnetometer. The micro-cantilever magnetometer is a silicon micro-fabricated MEMS electromagnetic device integrating a current loop of lithographically defined dimensions. Its stiffness can be calibrated with a precision of 5% by the method described by Majstrzyk et al. [4]. The deflection of the magnetometer cantilever is measured with a scanning electron microscope and thus, through knowing the bias current, it is possible to determine the magnetic field generated by the e-beam column in a defined position and at a defined magnification.
13
Content available remote Synthesis, electrical and magnetic properties of polymer coated magnetic nanoparticles for application in MEMS/NEMS
Javid Muhammad Arshad, Sajjad Muhammad, Ahmad Saeed, Khan Muhammad Azhar Shahid, Nadeem Khalid, Amin Niama, Mehmood Zahid
Materials Science Poland
|
2020
|
Vol. 38, No. 4
553--558
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.
14
Content available Digital analysis of geo-referenced concrete Scanning Electron Microscope (SEM) images
Ahamad Mohd Sanusi S., Maizul Elly Nur Myaisara
Civil and Environmental Engineering Reports
|
2020
|
Vol. 30, no. 2
67--79
EN
The microstructural evaluation of complex cementitious materials has been made possible by the microscopic imaging tools such as Scanning Electron Microscope (SEM) and X-Ray Microanalysis. Particularly, the application of concrete SEM imaging and digital image analysis have become common in the analysis and mapping of concrete technology. In this study, six samples of two-dimensional (2D) SEM images were spatially resampled to produce Geo-referenced SEM sample images. Subsequently, they were analyzed and the intensity histogram plot was produced to facilitate visual interpretation. The consecutive digital image analysis performed was the enhancement and noise removal process using two filtering methods i.e. median and adaptive box filter. The filtered resampled images, then undergone the unsupervised K-Means classification process to collectively separate each individual pixel corresponds to the spectral data. By spatial segmentation of K-Means algorithms, the cluster groups generated were carefully reviewed before proceeding to the final analysis. From the resulting data, the mapping of the spatial distribution of k-cluster and the quantification of micro-cracks (voids) were performed. The results of the SEM images (1st - 4th sample) showed a higher percentage of k-cluster data indicating a good correlation with the major elemental composition of EDX analysis, namely Oxide (O), Silicon (Si) and Carbon (C). Meanwhile, the subjective visual assessment of the image (5th and 6th sample) has confirmed the micro-crack developments on the concrete SEM images upon which the crack density was 3.02 % and 1.30 %, respectively.
15
Content available remote Local temperature rise during the electron beam characterization Calculation model for the AlxGa1-xN at low dimensions
Leghrib L, Nouiri A.
Materials Science Poland
|
2018
|
Vol. 36, No. 1
51--55
EN
During the characterization by electron beam techniques including scanning electron microscope (SEM) and cathodoluminescence at low dimensions, some undesirable phenomena (unwanted effects) can be created, like the thermal effects (or electron beam damage), and these effects can damage the sample. This limits the information one can get from a sample or reduces image spatial resolution. In order to understand these effects, significant efforts have been made but these studies focused on the thermal properties, without a detailed study of the causes of nanoscale heating in the bulk of samples during the SEM-characterization. Additionally, it is very difficult to measure experimentally the heating because there are many variables that can affect the results, such as the current beam, accelerating energy, thermal conductivity and size of samples. Taking into account all the factors and in order to determine the local temperature rise during the electron beam characterization of AlGaN at low dimensions, we have used a hybrid model based on combined molecular dynamics and Monte Carlo calculation of inelastic interaction of electrons with matter to calculate the temperature elevation during the SEM-characterization which can be taken into account during the characterization of AlGaN at low dimension by electron beam techniques.
16
Content available remote Charakterystyka mikrostruktury pianobetonu o różnych gęstościach przy zastosowaniu technik mikroskopowych
Chung S. Y., Lehmann C., Elrahman M. A., Stephan D.
Cement Wapno Beton
|
2018
|
R. 21/83, nr 3
216--225
PL
W pracy przedstawiono wyniki badań próbek pianobetonów z użyciem skaningowej mikroskopii elektronowej oraz mikrotomografii rentgenowskiej. Scharakteryzowano porowatość oraz właściwości matrycy cementowej betonów po różnych czasach dojrzewania. Gęstość decyduje w pierwszej kolejności o mikrostrukturze matrycy cementowej, a co za tym idzie właściwości pianobetonów. Jak można się było spodziewać, matryca cementowa jest bardziej zwarta w pianobetonach o większej gęstości i dojrzewających przez dłuższy okres. Średnica porów zmniejsza się, wraz ze zwiększaniem się gęstości betonów i jest bardziej stabilna w późniejszych okresach.
EN
In this paper a set of foamed concrete specimens with different densities was prepared, and microscopic techniques such as scanning electron microscopy and X-ray micro-computed tomography were used to characterize the specimens. The pore and solid characteristics of the foamed concrete at different ages were also examined to investigate the effect of aging on the materials. The microstructure of cement matrix and thus the properties of foamed concrete are strongly affected by the density of concrete. As it should be expected, the cement matrix is denser in concrete of higher density and concrete cured for longer period. The pore size distribution of the foamed concrete shows the tendency to be composed of smaller pores as the density of the specimens is increasing and to became more stable after longer curing period.
17
Próby rekonstrukcji obrazu fotograficznego na podłożach papierowych. Cz. 3.
Kozielec T.
Przegląd Papierniczy
|
2017
|
R. 73, nr 5
349--356
PL
W artykule zaprezentowano wyniki badań nad rekonstrukcją obrazu fotograficznego z użyciem technik: obrazowania wielospektralnego, neutronowego (radiografia neutronowa) oraz obrazowania z wykorzystaniem technik opartych na użyciu promieniowania rentgenowskiego (MA-XRF, RTG). Zastosowano również techniki oparte na użyciu skaningowego mikroskopu elektronowego SEM/BSE i SEM/EDX. Określono, że najbardziej przydatną techniką do rekonstrukcji spłowiałego obrazu fotograficznego jest obrazowanie wielospektralne (widmo niebieskie i początek widma zielonego). Wszystkie pozostałe techniki nie powodują uczytelnienia się srebrowego obrazu fotograficznego. Zwrócono jednak uwagę na ich przydatność do innych rodzajów badań zabytkowych fotografii. Niniejsza część artykułu jest ostatnią – zamyka poruszoną problematykę badawczą, na której skupił się autor, z drugiej jednak strony ma ona za zadanie otworzenie drogi do dalszych poszukiwań.
EN
In this article the results of photographic image reconstruction investigation are discussed. The following techniques were used in this investigation: multispectral imaging, neutron imaging (neutron radiography) and X radiation techniques (MA-XRF, RTG). The techniques using scanning electron microscopy SEM/BSE and SEM/EDX were also applied. It was found that the most suitable method of faded image reconstruction was multispectral imaging. Other mentioned techniques did not cause the improvement of photographic image readibility. However, they are very useful in other kinds of historic photographs investigation. It is the last part of the article summing up the issues of author’s interest. On the other hand the goal of this part was to open the way for further research.
18
Content available Efekty ekstrakcji pyłku kwiatowego nadkrytycznym dwutlenkiem węgla®
Bakier S., Bajko E.
Postępy Techniki Przetwórstwa Spożywczego
|
2017
|
Nr 1
66--70
PL
W artykule przedstawiono wyniki badań ekstrakcji pyłku kwiatowego w postaci obnóży za pomocą ditlenku węgla w stanie nadkrytycznym. Badano wpływ sposobu przygotowania surowca na wydajność ekstrakcji oraz strukturę pojedynczych ziaren pyłku. Proces ekstrakcji realizowano przy ciśnieniu 35 MPa, w temperaturze 40°C przy przepływie CO2 wynoszącym 80 g/min przez 90 minut. Uzyskane wydajności ekstrakcji wynosiły od 0,86% ±0,25% do 1,52% ±0,2% masy obnóży przed ekstrakcją. Skład chemiczny uzyskanych ekstraktów identyfikowano za pomocą techniki chromatografii gazowej z detektorem masowym (GC-MS). Analiza GC-MS wykazała, że prawie 82 % ekstraktu stanowią związki o charakterze lipidowym, w tym 14,07 % nienasycone kwasy tłuszczowe. Badania z użyciem skaningowego mikroskopu elektronowego wykazały, że w wyniku działania nadkrytycznego ditlenku węgla nastąpiło zniszczenie zewnętrznych osłon ziaren pyłkowych.
EN
This article presents the results of studies on the extraction of components from bee pollen by supercritical dioxide carbon. The influence of the method of bee pollen preparation and process conditions on the extraction yield and the structure of bee pollen grains was investigated. The extraction was performed at the pressure 35 MPa, temperature 40°C, CO2 flow rate 80 g/min for 90 min. The obtained extraction yields ranged from 0,86% ±0,25% to 1,52% ± 0,2% mass of bee pollen. The chemical compounds of the extracts obtained from supercritical carbon dioxide extraction were identified by using gas chromatography-mass spectrometry (GC-MS). GC-MS analysis of the extract showed that lipids accounted for approximately 82 %, including 14,07 % unsaturated fatty acids. Scanning electron microscopy studies revealed that supercritical dioxide carbon treatment was an effective way to break cell wall of bee pollen.
19
Content available Effects of Aspect Ratio and Loading on the Mechanical Properties of Prosopis Juliflora Fibre-reinforced Phenol Formaldehyde Composites
Sujin Jose A., Athijayamani A., Ramanathan K., Sidhardhan S.
Fibres & Textiles in Eastern Europe
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2017
|
Vol. 25, no. 4 (124)
59--64
EN
In this paper, an attempt was made to use Prosopis juliflora fibres (PJFs) as a reinforcing agent for phenol formaldehyde (PF) composites. Mechanical properties of the composites were studied for various fibre aspect ratios (FAR) and fibre loadings (FL). A scanning electron microscope (SEM) was used to study the fractured surface of the composites. The peak range of mechanical properties was identified for composites with a FAR of 136 and fibre loading of 23.53 wt%. This study shows that the optimum FAR and fibre loading for PJFs were found to be 136 and 23.53 wt% in order to achieve good reinforcement with better mechanical properties in the PF resin matrix. Experimental results were observed to be in very good agreement with the theoretical.
PL
W pracy podjęto próbę wykorzystania włókien Prosopis juliflora jako środka wzmacniającego żywice fenolowo-formaldehydowe. Przy użyciu elektronowego mikroskopu skaningowego zbadano powierzchnie przełomu kompozytów. Dla różnych wartości wydłużenia włókien (46, 136 i 227 mm) i udziału procentowego włókien w matrycy (4.88, 10.34, 16.51, 23.53 i 31.58 wt%) zbadano właściwości mechaniczne kompozytów. Na podstawie badań stwierdzono, że optymalne wydłużenie i zawartość włókien w matrycy to odpowiednio 136 mm i 23,53 wt%. Wyniki eksperymentalne charakteryzowały się dobrą korelacją z wynikami teoretycznymi.
20
Content available remote An investigation of abrasive and erosion behaviour of AA 2618 reinforced with Si3N4, AlN and ZrB2 in situ composites by using optimization techniques
Selvaraj S. K., Nagarajan M. K., Kumaraswamidhas L. A.
Archives of Civil and Mechanical Engineering
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2017
|
Vol. 17, no. 1
43--54
EN
AA 2618 alloy matrix material is mixed with silicon nitride (Si3N4), aluminium nitride (AlN), and zirconium boride (ZrB2) reinforcement particles. AA 2618 composites were prepared by stir casting method by the following various amounts of weight percentage (wt%): about 0, 2, 4, 6 and 8. AA 2618 composites were analyzed by various mechanical properties such as micro-hardness, tensile strength, and compressive strength. The mechanical properties were increased by increasing wt% of reinforcements. The microstructure and worn surfaces’ analysis have been done for the dispersion and bonding structure of the reinforced particles in composites; also, the AA 2618 composites were involved with different characterizations such as abrasive and erosion wear tests at various wt% to find the wear resistance of the composites. The mass loss was considered as the result of wear testing. Before and after worn surface has been analyzed by scanning electron microscope (SEM), the abrasive and erosion wear test results were analyzed by using traditional and nontraditional techniques like Taguchi method, analysis of variance (ANOVA) and genetic algorithm (GA) to obtain the better wear resistance of various wt% of AA 2618 composites and to study the most influencing input and output process parameters by using different optimization techniques.
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