Specificities of Scanning Electron Microscopy and Histological Methods in Assessing Cell-Engineered Construct Effectiveness for the Recovery of Hyaline Cartilage

The object of this study was concrete samples of the cathedral and wall frescoes. The study solved the problem related to the destruction of concrete and wall frescoes under the long-term influence of biochemical and climatic factors. Samples of concrete for research and wall murals were obtained from a historic listed building. Using microbiological studies and scanning electron microscopy, damage to wall murals and concrete by microscopic fungi was established: Aspergillus fumigatus, Penicillium brevicompactum, Aspergillus niger, Cladosporium sphaerospermum. The study of concrete samples by the TPD-MS method showed the presence of an increased level of moisture and carbon compounds by 20 % in the test samples, compared to control. The sulfur content in all concrete samples was not significant. Determination of the mineral composition of concrete by X-ray diffraction showed the presence of Al2O3, 36–44 %, which indicates a significant clay content. The presence of NiTi, 53 %, and СoMg7O8, 46 %, in the concrete sample indicates the probable migration of the chemical elements of the paint pigments used to decorate the cathedral. The concrete control sample contained a significant amount of SiO2, up to 51 %, which is the main component of sand. A feature of the work is the determination of the corrosion effect on concrete under prolonged exposure to climatic and biological factors. The present study is distinguished by the use of non-destructive methods: microbiological studies, scanning electron microscopy, TPD-MS and X-ray diffraction to determine the destruction of concrete and wall frescoes of the building, which is a cultural heritage. The results of the study could be applied to the development and planning of restoration works for the restoration of buildings that have historical value

Section: Methodology Of Scanning Electron Microscopy Of Concrete Samplesmentioning

confidence: 99%

Determining the characteristics of concrete in a historical building under the influence of climatic and biological factors

Shkromada,

Fotina,

Ivchenko

et al. 2024

“…The microscopic structure of concrete was studied using scanning electron microscopy on a REM 106 device (VAT SELMI, Sumy, Ukraine) under the secondary electron mode in the range of electron-optical magnification from 200 to 5,000 times [16]. The study of the microscopic structure was carried out from different sides of the chips of the concrete sample.…”

Section: Scanning Electron Microscopy Techniquementioning

confidence: 99%

Improving the technique of protecting concrete floors in poultry houses

Fotina,

Petrov,

Havryliuk

et al. 2023

The object of the study was concrete floors in a poultry house with different types of litter. The paper addressed the problem of reducing microorganism contamination of concrete floors in poultry houses to prevent biological corrosion. Corrosion of the surface of the concrete floor in the form of the formation of calcium oxalate monohydrate crystals was established by scanning electron microscopy; microscopic fungi: A. pullulans, F. sporotrichioides, and A. niger were detected. The TPD MS method established that concrete samples obtained in a room with straw lose moisture by 51.52 % more, with granules – by 342.42 % (р≤0.05), with shavings by 6.06 %, compared to control. CO from concrete samples is released less with sawdust litter by 86.40 %, with straw – by 83.49 %, with shavings – by 76.69 %, with granules – by 69.90 % (р≤0.05). The CO2 content in concrete samples from the room with sawdust was lower by 86.88 % (р≤0.05), with straw – by 55.73 %, with shavings – by 38.52 %, with granules – by 23.77 %, compared to control without litter. Microbiological studies have established that 48 hours after disinfection, the total number of colonies of microorganisms on a concrete floor with a sawdust litter likely decreased by an average of 90.19 %, straw – by 91.62 %, shavings – by 79.76 %, granules – by 82.88 % (р≤0.05), in the control – by 83.73 %. It can be argued that the disinfectant destroys microorganisms on the concrete surface regardless of the type of substrate. The peculiarity of the experiment was the use of scanning electron microscopy and TPD MS methods to study structural changes in concrete. The research is distinguished by the use of a powdered disinfectant to reduce microbial damage to a concrete floor with different types of litter. The results of the experiment could be used in the aggressive environment of poultry houses to reduce the impact on concrete structures

“…A raster electron microscope with a mode of secondary electrons in the range of electron-optical magnifications from 200 to 5,000 times was used for research. To study the biofilms of microorganisms, concrete samples were fixed with 2.5 % glutaraldehyde on 0.2M phosphate buffer solution, dehydrated in a series of ethyl alcohols of increasing concentration, and sprayed with silver [24].…”

Section: Scanning Electron Microscopy Procedures For Concrete Samplesmentioning

confidence: 99%

Reducing the biogenic corrosion of concrete in a pigsty by using disinfectants

Шкромада

Фотіна

Dudnyk

et al. 2022

The object of this study is the regularity of changes in the biogenic destructive effect of microorganisms on the concrete structural elements of livestock facilities due to the use of the original liquid phase mixture of disinfectant based on aldehyde and surfactant. Microorganisms use construction materials as a substrate for growth and nutrition; they produce citric acid, which leads to a change in the composition and morphology of hydrated cement new formations. The composition of the microflora of the pigsty has been determined, and the minimum concentration of disinfectant based on glutaraldehyde and didecyl dimethyl ammonium chloride was found. By the TPD MS method, a decrease in the intensity of carbon dioxide (CO2) release in concrete samples during the heating of the sample to 900 °C was proved, compared to the control intact corrosion sample. Electron microscopy of concrete samples shows the presence of destructive changes and colonies of micromycetes. It was established that calcite was intensively released in the control sample of concrete, which retained its integrity and was not subjected to corrosion when heated to a temperature of 600 °C. Electron microscopy confirms the preservation of the homogeneous structure of concrete. The use of a disinfectant based on glutaraldehyde and didecyl dimethyl ammonium chloride at a concentration of 1 % destroys colonies of micromycetes, 2 % – the shell of microorganisms, and 3 % – biofilm. Treatment of concrete with a disinfectant at a concentration of 3 % destroys microorganisms Aspergillus fumigatus and Penicillium oxalicum, inhibits the process of biological corrosion of concrete, and strengthens the structure of concrete. The results of the experiment can be applied to inhibit the corrosion of concrete and extend the life of building structures made of concrete through the use of a disinfectant based on aldehyde and didecyl dimethyl ammonium chloride at a concentration of 3 %.