Artykuły w czasopismach na temat „Stone – microscopy”
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1
Rao, Sudeep M., C. Jeffrey Brinker i Timothy J. Ross. "Environmental microscopy in stone conservation". Scanning 18, nr 7 (październik 1996): 508–14. http://dx.doi.org/10.1002/sca.1996.4950180707.
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Kim, K. M. "Electron microscopic pathology of urinary stones". Proceedings, annual meeting, Electron Microscopy Society of America 45 (sierpień 1987): 674–75. http://dx.doi.org/10.1017/s0424820100127797.
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Urolithiasis occurs commonly. With modern technology, stones can be easily removed. However, the major threat of urolithiasis is in its high recurrence rate. Many recurrences can be medically prevented. For medical prevention, proper knowledge of stone components is essential.Urinary stones have been analyzed mainly by x-ray diffraction, infrared spectroscopy and chemical analysis. Each method suffers from limitations in sensitivity and reliability. Primarily because of their inability to detect minor components of the stones, two or more methods are frequently combined. Recently it has become apparent that scanning electron microscopy (SEM), especially when combined with x-ray analysis (XA), has a sensivity in stone analysis exceeding other conventional methods.SEM of urinary stones did not gain popularity mainly due to the perceived high cost, the difficulty of sectioning stones, and the variability of crystal morphology.
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Spathis, Panayotis K., Maria Mavrommati, Eirini Gkrava, Vasilios Tsiridis, Sotiris P. Evgenidis, Ioannis Karapanagiotis, Vasilios Melfos i Thodoris D. Karapantsios. "Characterization of Natural Stone from the Archaeological Site of Pella, Macedonia, Northern Greece". Heritage 4, nr 4 (15.12.2021): 4665–77. http://dx.doi.org/10.3390/heritage4040257.
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The goal of the study was to characterize the limestone that was used extensively in the ancient city of Pella (Macedonia, Greece), the birthplace of Alexander the Great. An on-site examination of the building material was carried out to record the types of damage and to select sampling areas. A variation in the nature of the stone and the degree of deterioration, even between the stones that comprise a specific monument structure, was observed, with water absorption and biological colonization being the main factors resulting in the deterioration of the stone. A comprehensive microanalysis and testing scheme was conducted to fully characterize the mineralogical, chemical, mechanical and thermal properties of the stones collected from various areas of the archaeological site. Optical microscopy, XRD and SEM–EDX were used to investigate the chemical composition and the structure of the stone samples. Finally, other properties, such as porosity, specific gravity and water absorption, were measured. Surface alterations, material degradation and biological deterioration were observed in most samples. The results obtained using XRD showed that the dominant mineral phase of the limestone is calcite, with quartz and clay minerals also detected in traces. The microscopic examination of the samples showed that the main natural stone at the archaeological site is a marly limestone. Thermographical measurements showed that the decay of the stones due to ambient temperature variation and corresponding contraction/expansion phenomena may be relatively limited, as the stone exhibited a low thermal diffusivity. Moreover, high porosity values (12.06–21.09%) and low compressive strength (11.3–27.7 MPa) were recorded, indicating the vulnerability of the stone and the need to take conservation measures.
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Hassan A.A. Al-Jumaily, Omar A.M. Mohammad i Anwaar S.J. Al-Maadhidi. "The role of SEM and infrared spectroscopy techniques in identification of the mineralogy of kidney stones: case study from Fallujah City, Western Iraq". Tikrit Journal of Pure Science 25, nr 4 (2.08.2020): 44–52. http://dx.doi.org/10.25130/tjps.v25i4.270.
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The current study is concerned with the mineralogical aspects of kidney stones from urolithiasis patients of different ages and genders in Fallujah city hospital. The following techniques were implemented as follows; X - ray diffraction (XRD) used to recognize the mineral components of the studied kidney stones, Infrared Spectroscopy (IR) to discover the type of chemical compounds of the studied kidney stones, Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) to determine the mineralogy and the various chemical components in the kidney stones. The results show that the kidney stones are composed of five mineral groups and these are; mixed stone group, calcium oxalate, phosphate stone, uric acid, and cholesten. The cholesten has been diagnosed for the first time in Iraq, which might be linked to the diet type that includes high levels of cholesterol. Furthermore, the most common mineral group in the study area is the mixed stone which occurs in males more than females for the ages of 40 to 50 years old
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OUYANG, JIAN-MING, MU-HUA WAN i NA ZHOU. "STUDY OF NANOPARTICLES IN URINES BY TRANSMISSION ELECTRON MICROSCOPY". International Journal of Nanoscience 05, nr 06 (grudzień 2006): 769–73. http://dx.doi.org/10.1142/s0219581x06005133.
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The number, size and distribution of nanoparticles in urines of healthy people and stone patients were investigated by transmission electron microscopy (TEM). The results showed that the number of nanoparticles in healthy urines are more than that in lithogenic urines. The size of most nanoparticles in healthy urines ranges from 100 to 350 nm. However, the size of nanoparticles in patient urines changes from 100 nm to 1000 nm and more. A dynamic model about the formation of urinary stones was established. From this model, the nanoparticles in normal urines are stable, yet those in patient urines would easily aggregate to larger-size crystals and finally urinary stones formed. The results in this paper provide a new thought for preventing formation and recurrence of urinary stones.
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Zhang, Guang Na, Zhi Yue Xia, Jian Ming Ouyang i Li Kuan. "Study on Nano- and Microcrystallites in Urines of Uric Acid Stone Patients". Advanced Materials Research 655-657 (styczeń 2013): 1927–30. http://dx.doi.org/10.4028/www.scientific.net/amr.655-657.1927.
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The presence of crystallites in urine is closely related to stones formation. In this article, the components, morphology of nano- and micro-crystallites in urines of 20 uric acid (UA) stone formers as well as their relationship with the formation of UAstones were comparatively studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The main constituent of urinary crystallites was uric acid. Their particle size distribution was highly uneven, ranging from several nanometers to several tens of micrometers, and obvious aggregation was observed. These results showed that there was close relationship among stone components, urinary crystallites composition and urine pH.
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Gervasoni, Jacopo, Aniello Primiano, Pietro Manuel Ferraro, Andrea Urbani, Giovanni Gambaro i Silvia Persichilli. "Improvement of Urinary Stones Analysis Combining Morphological Analysis and Infrared Spectroscopy". Journal of Chemistry 2018 (2018): 1–7. http://dx.doi.org/10.1155/2018/4621256.
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Daudon et al. have developed a complex morphoconstitutional classification of renal stone in six different morphological types and several subtypes. According to this classification, a precise correspondence exists between causes of renal stones and subtypes with a great clinical relevance and can be considering a sort of shortcut for the metabolic diagnosis in renal stone patients. Now the diagnosis of causes of renal stones generally requires repeated biochemical investigations on urine and blood samples and usually remains presumptive. We analyzed 150 urinary stones both by stereoscopic microscopy and Fourier transform infrared spectroscopy. The comparison of 150 stones did not reveal any disagreement. We have only 20 partial agreement, and clinicians agreed that the imprecise information obtained with morphological analysis alone would have missed an important clinical finding only in 3 cases. In conclusion, in our opinion, the analysis of urinary stone must combine two different analytical techniques: morphological analysis by stereomicroscope and biochemical analysis with the FT-IR.
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Carmichael, Stephen W. "Microscopy Reveals That It’s Written in Stone!" Microscopy Today 23, nr 2 (marzec 2015): 8–11. http://dx.doi.org/10.1017/s1551929514001345.
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Wentrup-Byrne, E., L. Rintoul, J. L. Smith i P. M. Fredericks. "Comparison of Vibrational Spectroscopic Techniques for the Characterization of Human Gallstones". Applied Spectroscopy 49, nr 7 (lipiec 1995): 1028–36. http://dx.doi.org/10.1366/0003702953964813.
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A suite of human gallstones was investigated by vibrational spectroscopic techniques with a view to developing an effective characterization procedure. Using infrared microscopy, microspectroscopic mapping, infrared photoacoustic spectroscopy (PAS), and FT-Raman spectroscopy, we have examined both the chemical composition and the microstructure of the different categories of human gallstones. We show how infrared microscopy can be used to determine the chemical identity of particular microstructural features of a stone. Infrared mapping produces functional group maps of the surface of a gallstone and shows the actual distribution of the different chemical components. Good fluorescence-free FT-Raman spectra were obtained from all categories of stones except black stones, which gave a fluorescence background with no observable Raman spectrum. Of the vibrational techniques studied, PAS proved the most suited to the spectroscopic categorization of gallstones because data for the whole stone can be obtained with minimal sample preparation. The advantages and disadvantages of each technique are discussed.
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Khan, Saeed R. "Urinary stone analysis". Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 86–87. http://dx.doi.org/10.1017/s0424820100102511.
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Since crystalline composition of a urinary stone is an expression of urinary chemical conditions prevalent at the time of crystal nucleation and growth, a careful analysis of the stone and identification of constituent crystals is necessary for an understanding of the disease and the initiation of a proper medical regimen for the prevention of stone recurrence. Of the number of methods available, analytical electron microscopic techniques including scanning (SEM) and transmission electron microscopy (TEM), x-ray microanalysis (XRMA), and electron diffraction (ED) are gaining in popularity.For SEM, the dried stone is fractured through the middle and small pieces representing different areas of the stone are mounted on a carbon planchet or an aluminum stub using a double sticky tape or graphite paint. The specimen is then sputter coated with silver, gold or gold/palladium; or coated with carbon. For morphological examination alone, the specimen can be coated with any of the available conducting substances, but for XRMA the specimen should either be examined uncoated or be coated with carbon, or with a substance whose peaks in the XRMA spectrum do not interfere with the peaks of the elements of interest.
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Ciaramitaro, Veronica, Alberto Spinella, Francesco Armetta, Roberto Scaffaro, Emmanuel Fortunato Gulino, George Kourousias, Alessandra Gianoncelli, Eugenio Caponetti i Maria Luisa Saladino. "A New Methodological Approach to Correlate Protective and Microscopic Properties by Soft X-ray Microscopy and Solid State NMR Spectroscopy: The Case of Cusa’s Stone". Applied Sciences 11, nr 13 (22.06.2021): 5767. http://dx.doi.org/10.3390/app11135767.
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Hydrophobic treatment is one of the most important interventions usually carried out for the conservation of stone artefacts and monuments. The study here reported aims to answer a general question about how two polymers confer different protective performance. Two fluorinated-based polymer formulates applied on samples of Cusa’s stone confer a different level of water repellence and water vapour permeability. The observed protection action is here explained on the basis of chemico-physical interactions. The distribution of the polymer in the pore network was investigated using scanning electron microscopy and X-ray microscopy. The interactions between the stone substrate and the protective agents were investigated by means of solid state NMR spectroscopy. The ss-NMR findings reveal no significant changes in the chemical neighbourhood of the observed nuclei of each protective agent when applied onto the stone surface and provide information on the changes in the organization and dynamics of the studied systems, as well as on the mobility of polymer chains. This allowed us to explain the different macroscopic behaviours provided by each protective agent to the stone substrate.
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Mudronja, Domagoj, Frederik Vanmeert, Stjepko Fazinic, Koen Janssens, Darko Tibljas i Vladan Desnica. "Protection of Stone Monuments Using a Brushing Treatment with Ammonium Oxalate". Coatings 11, nr 4 (25.03.2021): 379. http://dx.doi.org/10.3390/coatings11040379.
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Stone monuments and buildings are susceptible to weathering. Carbonate-based stones are especially vulnerable in acidic environments, whereas magmatic acidic stones are more susceptible to chemical weathering in basic environments. To slow down surface corrosion of limestone and marble artworks/buildings, protective coatings which inhibit calcite dissolution have been proposed. In this work, samples from two stone types with different porosity were treated with ammonium oxalate (AmOx) to create a protective layer of calcium oxalate (CaOx) using the previously developed brushing method. Two different synchrotron microscopy experiments were performed to determine its protective capability. X-ray powder diffraction (SR-μ-XRPD) in transmission geometry allowed visualization of the distributions of calcium carbonate and oxalates along the sample depths. In a second step, X-ray fluorescence (SR-μ-XRF) was used to check the efficiency/integrity of the protective surface coating layer. This was done by measuring the sulfur distribution on the stone surface after exposing the protected stones to sulfuric acid. XRPD showed the formation of a protective oxalate layer with a thickness of 5–15 µm on the less porous stone, while a 20–30 µm thick layer formed on the more porous stone. The XRF study showed that the optimal treatment time depends on the stone porosity. Increasing the treatment time from 1 to 3 h resulted in a decreased efficiency of the protective layer for the low porosity stone. We assume that this is due to the formation of vertical channels (cracks) in the protective layer.
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Karatasios, Ioannis, Anastasia Michalopoulou, Maria Amenta i Vassilis Kilikoglou. "Modification of water transport properties of porous building stones caused by polymerization of silicon-based consolidation products". Pure and Applied Chemistry 89, nr 11 (26.10.2017): 1673–84. http://dx.doi.org/10.1515/pac-2016-1104.
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AbstractThis work studies the polymerization process of four different commercially available silicon-based polymers and their consequent effect on surface tension and water transport properties of natural stones used in architectural monuments, essential for modeling and predicting the durability of natural stones against weathering action of aqueous solutions. The four products studied consisted of two ethyl-silicate based materials, an alkyl-alkoxy siloxane oligomer with hydrophobic agents and finally, a silane/siloxane emulsion. In all cases, the morphology of the amorphous material deposited into the pore network of stones was examined by electron microscopy (SEM). The polymerization process was studied by infrared spectroscopy (FTIR) on both inert surface and porous stone substrate. The treated stone specimens were further tested after polymerization in terms of determination and comparison of water absorption coefficient, open porosity, pore size distribution (mercury intrusion porosimetry) and surface tension (contact angle measurements) properties. According to the analysis, the modification of the wetting properties of the stone surface should be related rather with the chemistry than the microstructure of the xerogels alone.
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Iordanidis, A., i J. Garcia-Guinea. "Analytical geochemistry in the service of medicine: An experimental study of urinary stones from Northern Greece". Bulletin of the Geological Society of Greece 47, nr 2 (24.01.2017): 818. http://dx.doi.org/10.12681/bgsg.11118.
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Knowledge of the precise human biomineral composition may allow physicians to recommend an appropriate prophylactic therapy for the patient and thus prevent or delay the stone recurrence. The present study focuses on the application of complementary analytical techniques to the characterization of human urinary stones. Several gallbladder and renal stone samples were obtained from patients dwelling in areas of northern Greece. A comprehensive analytical study took place, employing the following, common in analytical geochemistry, techniques: Environmental Scanning Electron Microscopy (ESEM) coupled to Energy Dispersive System (EDS), X-Ray Diffraction (XRD), thermogravimetry (TG), μRaman spectroscopy and Cathodoluminescence (CL). A detailed determination of morphological, micro-structural, molecular, chemical and mineralogical characteristics of the urinary stone samples was achieved. It was evident by our study the application of powerful analytical techniques could substantially help the medical advisors to ascribe a medical treatment of diseases related to stone formation.
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Kishorkumar, Poriya. "Physical Analysis of Kidney Stones:Metabolic Basis and Physical Practice". Acta Crystallographica Section A Foundations and Advances 70, a1 (5.08.2014): C115. http://dx.doi.org/10.1107/s2053273314098842.
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The kidneys play an important role in eliminating waste products from the body. Kidneys are a major source of morbidity and health care expenditure. They play an equally vital role in conservation of salt and water as the regulation of body's "internal environment". The past century has witnessed remarkable technological advances in the treatment and removal of Kidney Stones. Artificial Kidney and transplantation of Kidneys are today's reality, but advanced in prevention have been delayed by the incomplete understanding of what causes of stone formation. It is still unclear that how the Kidney Stones are grown in Kidneys. Investigation of kidney stone is based on urine chemistry, rather than physical analysis of stone itself. Such investigations does not explain the pathophysiology of stone formations. Chemical analysis and investigations can only be determines radical and ions but cannot resolve the crystalline entities. The present communication is an attempt to collect and prepared a huge data base for such samples. Naturally grown and surgically removed kidney stones were collected from various urological hospitals of Gujarat State with prescribe format. Such samples were analyzed with data analysis, and sophisticated physical tools like Scanning Electron Microscopy(SEM), Electron Dispersion Analysis by X-Rays(EDAX), Etching studies of such samples were made using inhibitor drug component as an Etchant.
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Aguiar, Mariane Costalonga de, Maria Carolyna Sopeletti Fernandes, Maria Angelica Kramer Sant’Ana, Viviana Possamai Della Sagrillo, Alexandre dos Santos Anastácio i Monica Castoldi Borlini Gadioli. "Eco-Efficient Artificial Stones Produced Using Quartzite Quarry Waste and Vegetable Resin". Sustainability 16, nr 1 (27.12.2023): 247. http://dx.doi.org/10.3390/su16010247.
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The ornamental stone industry plays a crucial role in the world economy, and thus the production process of ornamental stones generates a large volume of waste that is normally destined for landfills. Given the growing market import of artificial stones, there is a need for more sustainable practices to reduce waste and improve the use of natural resources. Thus, the present study aims to develop artificial stones with waste from the ornamental stone extraction process from the quarry, and vegetable polyurethane resin derived from castor oil, in order to analyze its viability in the production of artificial stone slabs. The wastes used in this work were three quartzites, fragmented and mixed with three grain sizes, called coarse, medium, and fine. These wastes were characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermal analysis (TGA/DTG/DSC). Artificial stone slabs were produced using 15 wt.% vegetable polyurethane resin derived from castor oil and 85 wt.% ornamental stone wastes (quartzite). These slabs underwent apparent density, water absorption, porosity, 3-point flexural strength, scanning electron microscopy (SEM), petrography, and X-ray diffraction (XRD) tests. According to the results obtained, it was possible to prove the technical viability of manufacturing artificial stones with ornamental stone wastes and with the use of vegetable polyurethane resin derived from castor oil. The use of these raw materials not only resulted in the manufacture of a new material but also in an environmentally conscious and sustainable approach, following precepts such as the circular economy. The creation of these eco-efficient products is a significant contribution to the search for solutions that value environmental preservation and the optimization of natural resources.
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Guo, Xuying, Zhiyong Hu, Saiou Fu, Yanrong Dong, Guoliang Jiang i Ying Li. "Experimental study of the remediation of acid mine drainage by Maifan stones combined with SRB". PLOS ONE 17, nr 1 (19.01.2022): e0261823. http://dx.doi.org/10.1371/journal.pone.0261823.
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The problems of acid mine drainage (AMD) in coal mine acidic wastewaters arise from a range of sources, including severe pollution with heavy metals and SO42- and difficulties during treatment. Based on the ability of Maifan stone to adsorb heavy metals and the dissimilatory reduction of SO42- by sulfate-reducing bacteria (SRB), Maifan stone-sulfate-reducing bacterium-immobilized particles were prepared via immobilization techniques using Shandong Maifan stone as the experimental material. The effects of Maifan stones containing SRB on mitigating AMD were investigated by constructing Dynamic Column 1 with Maifan stone-sulfate-reducing bacterium-immobilized particles and by constructing Dynamic Column 2 with SRB mixed with Maifan stones. By the use of adsorption isotherms, adsorption kinetics, a reduction kinetics model and X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies, the mechanism by which Maifan stone-sulfate-reducing bacterium-immobilized particles mitigate AMD was revealed. The results showed that the total effect of Maifan stone-sulfate-reducing bacterium-immobilized particles on AMD was better than that of biological Maifan stone carriers. The highest rates for the removal of Fe2+, Mn2+, and SO42- in AMD were 90.51%, 85.75% and 93.61%, respectively, and the pH value of the wastewater increased from 4.08 to 7.64. The isotherms for the adsorption of Fe2+ and Mn2+ on Maifan stone-sulfate-reducing bacterium-immobilized particles conformed to the output of the Langmuir model. The adsorption kinetics were in accordance with Lagergren first-order kinetics, and the kinetics for the reduction of SO42- conformed to those of a first-order reaction model.
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Armal, Forough, Luís Dias, José Mirão, Vera Pires, Fabio Sitzia, Sérgio Martins, Mafalda Costa i Pedro Barrulas. "Chemical Composition of Hydrophobic Coating Solutions and Its Impact on Carbonate Stones Protection and Preservation". Sustainability 15, nr 22 (20.11.2023): 16135. http://dx.doi.org/10.3390/su152216135.
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The decay diagnosis and conservation of stone-built heritage is becoming a worldwide concern, especially when stone decay causes chromatic changes in the original stone aesthetics, which directly impacts its sociocultural value. Among all the causes of stone decay, water action is identified as the major cause of stone decay and chromatic changes in stone building materials; hence, protective eco-friendly hydrophobic coatings are the efficient and fundamental options to prevent penetrating water into the stone. This paper aims to contribute to tackling water action on natural building stones by studying three different commercial hydrophobic coatings and finding out the correlation between the effectivity, compatibility, and durability of these coatings and the physical, chemical, and mineralogical features of four distinct types of limestone, one calcitic dolomite, four kinds of marble, and one granitoid. Nine different natural stones have been chosen due to their variations in physical, chemical, and mineralogical natures. A multi-analytical approach was adopted through digital microscopy and colourimetry assays to assess the compatibility of the hydrophobic coatings, accelerating ageing in climatic chambers to assess their durability, optical tensiometer analyses to evaluate the hydrophobic effectiveness, and h-XRF and XRPD for determining the chemical and mineralogical composition of stone samples. The results obtained demonstrate that the coating composed of silane/siloxane with modified fluorinated additives (FAKOLITH FK-3 Plus Nano) is the most effective, compatible, and durable coating among the selected hydrophobic coatings. These results can be considered the pioneering steps for developing eco-friendly and cost-effective coatings.
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Tzavellos, Stelios, Giovanni L. Pesce, Yu Wu, Alison Henry, Simon Robson i Richard J. Ball. "Effectiveness of Nanolime as a Stone Consolidant: A 4-Year Study of Six Common UK Limestones". Materials 12, nr 17 (22.08.2019): 2673. http://dx.doi.org/10.3390/ma12172673.
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Protecting stone buildings from weathering and decay is a major challenge in the conservation of built heritage. Most of the stone consolidants currently available are well suited to silicate stones, but are less compatible with limestone. In this paper we present for the first time the results over a 4-year period of various consolidation treatments carried out using nanolime on 6 of the most representative and significant stones used in historic buildings in the United Kingdom. Tests investigated the influence of stone type, environmental conditions and pre-treatments on the effectiveness of the consolidation treatment. A comprehensive and rigorous testing programme was carried out to evaluate the short (12 weeks) and longer-term (4 years) effects. Stone samples were characterised before and after treatment using light and electron microscopy, sorptivity tests and a novel methodology employing drilling resistance to interrogate the near surface effects. Results show that for some of the stones, such as Clunch and Bath Stone, the positive effect of the treatment with nanolime is noticeable after 4 years since application. However, results for other stones such as Portland and magnesian limestone showed that the initial beneficial effect of the treatment is reduced after 4 years. Nanolime treatment of Ham Stone produced an unnoticeable effect on the continuous natural reduction of the drilling resistance of the specimen over time. The results presented are of immense value to conservators as they provide essential guidance on the most appropriate repair approach. Impact to the conservation industry will be to avoid the use of nanolime on stones where there is no perceivable benefit, reducing the risk of adverse effects, including potential damage to buildings. In additional costs will be saved which might otherwise have been spent on ineffective treatments.
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Doehne, Eric. "ESEM and Video Microscopy Studies in Stone Conservation". Microscopy and Microanalysis 3, S2 (sierpień 1997): 613–14. http://dx.doi.org/10.1017/s1431927600009958.
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Observation of stone deterioration using in situ,time-lapse microscopy techniques has revealed previously undescribed material behaviors that help to explain the destructive effects of several important processes in wall paintings, historic structures and monuments. It has long been acknowledged that cyclic stresses imparted by humidity changes, wet-dry cycling, and the crystallization and hydration of soluble salts, are important agents in the deterioration of these porous structures. The crystallization of salts is a particularly serious conservation problem (Arnold, 1975). Over time, cyclic salt crystallization results in the physical breakdown of the material (Goudie, 1993). Objects affected by such processes are often difficult to conserve since they are weak to begin with and the presence of salt inhibits the curing of some common conservation materials (Price and Kumar, 1994).Sodium sulfate is one of the most damaging of salts, apparently because it expands during the transition from the anhydrous phase (Na2SO4; thenardite) to the decahydrate form (Na2SO4•l0H2O; mirabilite).
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Daudon, Michel, Dominique Bazin, Gilles André, Paul Jungers, Alain Cousson, Pierre Chevallier, Emmanuel Véron i Guy Matzen. "Examination of whewellite kidney stones by scanning electron microscopy and powder neutron diffraction techniques". Journal of Applied Crystallography 42, nr 1 (9.01.2009): 109–15. http://dx.doi.org/10.1107/s0021889808041277.
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Kidney stones made of whewellite,i.e.calcium oxalate monohydrate, exhibit various morphological aspects. The crystalline structure of whewellite at the atomic scale was revisited through a single-crystal neutron study at room temperature using a four-circle automated diffractometer. The possible relationships between the various morphological types of whewellite stones and their structural characteristics were examined at the mesoscopic scale by the use of scanning electron microscopy and at the nanometric scale by powder neutron diffraction. All types of whewellite stones displayed a similar structure at the nanometric scale. However, significant differences were found at the mesoscopic scale. In particular, the crystallites in kidney stones resulting from a genetic hyperoxaluria exhibited a peculiar structure. There was a close relationship between stone morphology and crystallite organization at the mesoscopic level and the effectiveness of extracorporeal shockwave lithotripsy.
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Li, Qi Shan, Ming Cheng Liu i Qi Long Jiang. "The Study of Structure and Energy Domain of ZiJin Stone". Advanced Materials Research 753-755 (sierpień 2013): 85–87. http://dx.doi.org/10.4028/www.scientific.net/amr.753-755.85.
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It is mainly addressed the relation between the structure and the energy domain using scanning electron microscope (SEM), transmission electron microscopy (TEM) to observe the micro structure. It indicates that some specific micro structures exiting in the Zijin Stone, such as the nanocrystal structure, nanofiber structure, and nanolayer structure, by which the capacities of releasing anion, bactericidal effect can to some extent be explained.
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Ferrazza, Livio, María T. Pastor Valls, Gemma M. Contreras Zamorano, David Juanes Barber, Roxana Radvan, Alexandru Chelmus, Lucian Ratoiu, Luminita Ghervase, Ioana Maria Cortea i Pilar Ortiz. "Multidisciplinary Approach Applied to the Diagnosis of the Facade of the Arciprestal Church of Santa María de Morella (Castellón, Spain)". Scanning 2019 (7.05.2019): 1–14. http://dx.doi.org/10.1155/2019/2852804.
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This paper deals with the development of a multidisciplinary study on the current state of conservation of the facade of the Arciprestal Church of Santa María de Morella (Castellón, Spain), a work of the Gothic period of great historical and artistic value. The aim of this diagnosis was to undertake the preventive conservation actions required and increase the knowledge about the conservation of paintings on stones. During the diagnosis scanning, electron microscopy was demonstrated to be a valuable analytical method for wall paintings on stone. The facade, which since its construction has not undergone major architectural changes, has reached our days as it was configured in its creation, adding the traces of the passage of time and interventions that have suffered polychromies. Because of the conservation situation, it was decided to have an interdisciplinary project for the structural study of the work, an exhaustive study of the materials and their state of conservation. The study of the materials includes the identification of stone supports, mortars, the pictorial technique of the original and added polychromies, and the superficial patinas. On-site studies were carried out by ground penetration radar (GPR) and X-ray fluorescence (XRF). Among the techniques used in laboratory were optical polarized light microscopy (MO-LP), X-ray diffraction (XRD), scanning electron microscopy with microanalysis (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR). The study allowed to determine the different pathologies of alteration and degradation of stone substrate and polychromies, chromatic alterations, biological patinas, etc. During this study, it was demonstrated that the diagnosis of wall paintings is a complex issue that needs to be addressed in a multidisciplinary approach, where scanning electron microscopy with microanalysis is the key methodology to get a deeper understanding of subsurface characterization of wall paintings and highlight the weathering processes. In a second phase of previous studies, this technique (SEM) has been used in assessing the viability of consolidation systems and cleaning both the stone and the polychrome.
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Sinicki, Ronald, i Christopher Viney. "Human gallstones: Specimen preparation and light microscopy". Proceedings, annual meeting, Electron Microscopy Society of America 50, nr 1 (sierpień 1992): 734–35. http://dx.doi.org/10.1017/s0424820100124070.
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Several methods for removing gallstones from the human body are in use or under investigation. They range from noninvasive techniques (dissolving; ultrasound lithotripsy), through minor surgery (use of wire basket lithotriptor; laser lithotripsy), to major surgery. The choice of procedure seeks to accomplish removal of stones while minimizing the cutting of patient tissue, the post-treatment rehabilitation time, and the overall cost. The effectiveness of a given procedure will vary, depending on the size and number of stones present, and especially on their composition and microstructure. Attempts have therefore been made to correlate gallstone structure (from computerized tomography studies or magnetic resonance imaging with the least severe procedure needed to break up and remove the stone. Such empirical correlations can be facilitated by additional in vitro microstructural characterization of stones, which attempt to relate the in vivo observations to likely fracture paths and mechanisms. It is convenient to distinguish between three broad categories of gallstone. Cholesterol gallstones are associated with cholesterol supersaturation, when the level of cholesterol in bile exceeds the amount that the bile salts can keep in solution; they contain more than 25 wt% cholesterol and are relatively rare. Pigment gallstones contain less than 25 wt% cholesterol, and result from the precipitation and agglomeration of bilirubin and other inorganic salts. Mixed stones are the most common, and form the subject of our present investigations. Viewed in cross-section, they contain radiating crystals of cholesterol, together with concentric layers of apparently amorphous pigment. There are few literature references to the study of gallstone structure by light microscopy. We found only one reference to the microscopy of thin sections; others described low resolution reflected light studies of surfaces generated by dividing stones with a sudden impact delivered to a sharp knife. The drought of high resolution light micrographs even extends to pathology atlases.
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Sun, Xin-Yuan, Jian-Ming Ouyang, Feng-Xin Wang i Yu-Shan Xie. "Formation Mechanism of Magnesium Ammonium Phosphate Stones: A Component Analysis of Urinary Nanocrystallites". Journal of Nanomaterials 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/498932.
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The components of urinary nanocrystallites in patients with magnesium ammonium phosphate (MAP) stones were analyzed by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectrometer, high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), fast Fourier transformation (FFT), and energy-dispersive X-ray spectroscopy (EDS). The main components of the stones were MAP hexahydrate (MAP·6H2O), magnesium hydrogen phosphate trihydrate (MgHPO4·3H2O), and a small amount of calcium phosphate (CaP), while the main components of urinary nanocrystallites were MgHPO4·3H2O, CaP, and MAP monohydrate (MAP·H2O). MAP·H2O induced the formation of MAP stones as seed crystals. MgHPO4·3H2O was accompanied by the appearance of MAP·6H2O. The formation mechanism of MAP stones and influencing factors were discussed on the basis of the components of urine nanocrystallites. A model diagram of MAP stone formation was also put forward based on the results. Formation of MAP stones was closely related to the presence of high amounts of MAP crystallites in urine. Urinary crystallite condition and changes in urine components could indicate the activity of stone diseases.
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Ribeiro, Carlos Eduardo Gomes, Rubén Jesus Sánchez Rodríguez, Carlos Maurício Fontes Vieira, Eduardo Atem Carvalho, Verônica Scarpini Cândido i Sergio Neves Monteiro. "Fabrication of Artificial Stone from Marble Residue by Resin Transfer Molding". Materials Science Forum 775-776 (styczeń 2014): 336–40. http://dx.doi.org/10.4028/www.scientific.net/msf.775-776.336.
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Artificial stones have recently been worldwide commercialized but are still not produced in Brazil. This has motivated efforts for the local fabrication of a similar stone. Thus, an artificial ornamental stone (AOS) was fabricated by means of a resin transfer molding (RTM) process. Marble residues were placed inside a hermetic mold under vacuum. A still fluid polyester resin, already mixed with a catalyst and a thinner, was injected into the mold. After curing, the density and water absorption of the AOS were evaluated. The material was also subjected to both compression and bend mechanical tests. The AOS microstructure was analyzed by scanning electron microscopy, which was then related to the obtained physical and mechanical properties.
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Dinda, Shilpa, Souradut Ray i Amal Kumar Mondal*. "Micro-morphological and morphometric characters analysis of Silica Bodies (SB) on leaf epidermal cells of five selected taxa in the Sub-family panicoideae based on Analytical Microscopy (AM): A systematic approach". Annals of Plant Sciences 6, nr 01 (31.12.2016): 1504. http://dx.doi.org/10.21746/aps.2017.01.004.
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Plants have unique capability to deposit silicon (si) with and between the cells and thus creating casts of the cells commonly known as silica bodies (plant stones). Silicon are very abundantly present only in the family Poaceae among monocotyledon. These silica bodies contain the composition of silicon to form different structural diversity of stone cells like long or short bar with rounded or semi rounded spheres dumbbell shaped, sinuous elongated rectangular, narrow elliptical rectangular, randle, polylobed and cross shaped etc. Light (LM), Polarized (PM), Fluorescence Microscopy (FM) and Scanning Electron Microscope (SEM) were used for better micro-morphological study. These micro characters might be applied numerically by UPGMA method to solve different taxonomic problems within familial, generic and species level and compared to other systematics.
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Tsampali, Evangelia, Stamatios Amanatiadis, Georgios Karagiannis i Maria Stefanidou. "Inspecting the healing process in an artificial stone used for repair works containing crystallines". Technical Annals 1, nr 1 (22.12.2022): 152–62. http://dx.doi.org/10.12681/ta.32160.
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Stone has been a basic building material of different monuments and structural components such as foundations and masonry. At the same time, dif-ferent types of stones have been used for decorative architectural elements, such as cornices, reliefs, colonnettes, and corbels. The maintenance of stone ele-ments is essential for the continuity of these structures. Many studies have been performed to produce stones with artificial materials. This study aims to present a new approach to artificial stone with self-healing capability. Crystallines have been implied in two different dosages: 0.8 and 1.6% w./w, to achieve this goal. The addition of the crystalline admixtures affected the physical properties, de-creasing the porosity and the capillary absorption, proving the sealing properties of the admixtures. The self-healing efficiency has been tested with the sorption test, recovery of compressive strength, and 3D acoustic microscopy. The crys-talline admixtures accelerate the self-healing, increasing the sealing efficiency by 20% and recovering compressive strength by 15%. The analysis by 3D to-mography provided results that confirm the healing of the crack hasn't occurred only on the surface but extended to a certain depth.
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Rovella, N., M. Musella i D. Barca. "Characterization of stone tesserae from “The Indian Triumph of Dionysus” Mosaic (Casignana, Reggio Calabria, Italy)". Journal of Physics: Conference Series 2204, nr 1 (1.04.2022): 012036. http://dx.doi.org/10.1088/1742-6596/2204/1/012036.
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Abstract The archaeological site of Casignana (Reggio Calabria) represents one of the most important Roman sites of Southern Italy thanks to its extension and refinement of its mosaics such as the “Indian Triumph of Dionysus”. Its stylistic complexity is related also to the wide range of polychrome stone tesserae used. For this reason, a minero-petrographic and geochemical characterization of some tesserae was carried out by Polarized Optical Microscopy (POM), Scanning Electron Microscope (SEM), and Electron probe microanalyzer combined with wavelength dispersive X-ray spectroscopy (EPMA-WDS). The results suggested the heterogeneity of the stone tesserae in terms of petrographic features and the probable provenance from both local and not sites.
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Leung, Derek D. V., i Andrew M. McDonald. "Taking Rocks for Granite: An Integrated Geological, Mineralogical, and Textural Study of Curling Stones Used in International Competition". Canadian Mineralogist 60, nr 1 (1.01.2022): 171–99. http://dx.doi.org/10.3749/canmin.2100052.
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ABSTRACT The duopoly of curling stone sources suitable for international competition (Ailsa Craig, Firth of Clyde, Scotland and Trefor, Llŷn Peninsula, North Wales) has led to a long-held paradigm that the rocks from these localities are geologically unique. To evaluate this paradigm, we provide the first comprehensive, detailed analyses of the geological, mineralogical, and textural properties of curling stones, with a focus on three main areas: (1) the collective features of all curling stone lithologies, (2) the differences among the lithologies used for running bands versus striking bands, and (3) the presence of quartz, whose brittleness was previously considered to be undesirable in curling stones. The four curling stone varieties from the two localities (Ailsa Craig Blue Hone, Ailsa Craig Common Green, Blue Trefor, and Red Trefor) were analyzed using petrography, scanning electron microscopy, digital image analysis, powder X-ray diffraction, and normative mineralogy, with the following results: The curling stone varieties that are suitable for international competition can be broadly characterized as fine- to medium-grained, sparsely porphyritic to glomeroporphyritic, weakly to moderately altered, massive to weakly foliated, Phanerozoic granitoids (sensu lato). All four varieties are composed of feldspar (65–80 mod.%, with albite being the dominant component) and quartz (15–25 mod.%), along with mafic and accessory minerals (5–20 mod.%). The Ailsa Craig suite is classified as alkali feldspar quartz syenite, whereas the Trefor suite ranges from quartz monzogabbro (Blue Trefor) to granodiorite-granite (Red Trefor). None are strictly classified as granite.Predominantly equigranular textures are preferred for running bands (Ailsa Craig Blue Hone), whereas seriate to glomeroporphyritic textures are preferred for striking bands (Ailsa Craig Common Green, Blue Trefor, and Red Trefor). These are consistent with observations of used curling stones: pitting adversely affects larger grains in the running band, whereas a wider grain-size distribution correlates with fewer crescent-shaped fractures in the striking band.The appreciable abundance of unstrained, interstitial quartz (15–25 mod.%) in all curling stone samples challenges the longstanding belief of its absence and undesirability in curling stones. The degree of strain in quartz is likely to be a key criterion for selecting prospective curling stone materials. In conclusion, none of the examined characteristics of curling stones are unique in comparison to granitoids worldwide.
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Li, Chuanchang, Huan Ma, Baoshan Xie, Bo Zhang, Xinbo Zhao, Mengfan Wang, Zhangxing He, Wei Li i Jian Chen. "A Comparison of Mineralogical and Thermal Storage Characteristics for Two Types of Stone Coal". Minerals 9, nr 10 (29.09.2019): 594. http://dx.doi.org/10.3390/min9100594.
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Understanding the mineralogical and chemical characteristics of stone coal is imperative for exploring the thermal storage characteristics of stone coal. Two types stone coal (SCwt and SChc) were sampled from the pond of a stone coal mine in Henan province (China), and the chemical composition, phase composition, and thermal behavior of the stone coal were investigated. Furthermore, the petrography of the stone coal was studied in detail. The mineral phases of the stone coal were quartz, kaolinite, roscoelite, and goethite, as distinguished by reflected light microscopy and further proven by scanning electron microscope-energy dispersive spectrometer (SEM-EDS). The thermal conductivity of SCwt was 0.19 W m−1 K−1, while that of SChc was 0.24 W m−1 K−1. Stearic acid (SA) was blended with SCwt and SChc to prepare SA/SCwt and SA/SChc composites via an impregnation method, respectively. The thermogravimetric (TG) curves show that the loading capacity of SChc, at 17.40%, is higher than that of SCwt (16.63%). The thermal energy storage capacities of SA/SCwt and SA/SChc composites were 29.21 J g−1 and 33.02 J g−1 according to a differential scanning calorimetry (DSC) analysis. Therefore, SChc is a potential candidate for thermal storage applications due to more obvious thermal storage characteristics, including higher thermal conductivity and loading capacity.
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Badry, Amr A. El, Mahmoud A. M. Mokbel, Ismail El Mofty i Amira H. Mohamed. "Nanobacteria: An Infectious Cause for Salivary Stone Formation and Recurrence". Clinical medicine. Ear, nose and throat 3 (styczeń 2010): CMENT.S5147. http://dx.doi.org/10.4137/cment.s5147.
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Nanobacteria (NB) contribute to pathological calcification in the human and animal body. It has been isolated from salivary stones and suggested that it may act as a nucleus for the initiation of these stones. In the present study, we examined its role in the recurrent salivary gland stones using immunodetection with NB-specific monoclonal antibodies and scanning electron microscopy (SEM) hoping to provide a method for preventing the recurrence of these stones in the patient that has suffered from salivary stones. Our study comprised 30 patients with recurrent salivary gland stones (group I) and 30 patients with salivary gland stones for the first time (group II), in addition to 30 normal controls (group III). We could detect 100–500 nm nanoparticles in 24/30 (80%) cases in group I with significant difference <0.05 and <0.01 when compared with group II and group III in which they were detected in 19/30 (63.3%) and 6/30 (20%) respectively. Also there was a significant difference <0.05 between group II and group III. We proposed that salivary stone formation is a nanobacterial disease initiated by bacterial infection. This bacteria may play an important role in the recurrence of salivary stone. So the use of calcium chelator, ethylene diamine tetra acetic acid (EDTA), before or in combination with the suitable antibiotic that is given in an amount effective to inhibit or prevent the growth and development of nanobacteria may eradicate these stones and prevent their recurrence.
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Sofińska-Chmiel, Weronika, Marta Goliszek, Marek Drewniak, Aldona Nowicka, Marcin Kuśmierz, Agnieszka Adamczuk, Paulina Malinowska, Ryszard Maciejewski, Małgorzata Tatarczak-Michalewska i Eliza Blicharska. "Chemical Studies of Multicomponent Kidney Stones Using the Modern Advanced Research Methods". Molecules 28, nr 16 (16.08.2023): 6089. http://dx.doi.org/10.3390/molecules28166089.
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Defining the kidney stone composition is important for determining a treatment plan, understanding etiology and preventing recurrence of nephrolithiasis, which is considered as a common, civilization disease and a serious worldwide medical problem. The aim of this study was to investigate the morphology and chemical composition of multicomponent kidney stones. The identification methods such as infrared spectroscopy (FTIR), X-ray diffraction (XRD), and electron microscopy with the EDX detector were presented. The studies by the X-ray photoelectron spectroscopy (XPS) were also carried out for better understanding of their chemical structure. The chemical mapping by the FTIR microscopy was performed to show the distribution of individual chemical compounds that constitute the building blocks of kidney stones. The use of modern research methods with a particular emphasis on the spectroscopic methods allowed for a thorough examination of the subject of nephrolithiasis.
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Purbani, Debora Christin, Ade Lia Putri i Moh Habibi. "Epilithic Microalgae Isolated from Biofilm on Borobudur Temple Stone". Journal of Tropical Biodiversity and Biotechnology 5, nr 3 (14.12.2020): 239. http://dx.doi.org/10.22146/jtbb.59216.
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Borobudur Temple is a historical heritage building located in an open area and made of porous building materials (stone materials). This condition makes the Borobudur Temple susceptible to various problems related to degradation and weathering. Biodeterioration of Borobudur Temple may be caused by activities of living organisms present in the biofilm of stone. Continuous monitoring and evaluation need to be carried out by observing and isolating the growth of micro-organisms, including epilithic microalgae. Therefore, this study aims to isolate and identify epilithic microalgae from the biofilm on Borobudur Temple stones. Epilithic microalgae were isolated to obtain a uni-algae and maintained under culture conditions. The morphological of microalgae were observed using light microscopy, while the 18S rRNA gene sequence determined the molecular identification of microalgae for eukaryotic and 16S rRNA sequence for prokaryotic. A total of nine epilithic microalgae were successfully isolated from the biofilm of Borobudur Temple stones. The isolated were identified as Ankistrodesmus falcatus, Tetraselmis cordiformis, Pseudendoclonium arthropyreniae, Anabaena cylindrica, Nostoc gelatinosum, Oscillatoria limnetica, Messastrum gracile, Stigeoclonium aestivale, and Scenedesmus acuminatus. This is the first study for the identification of microalgae from Borobudur temple stones. The isolates will be collected and will be used as a source for further study.
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Bazin, Dominique, Michel Daudon, Gilles André, Raphael Weil, Emmanuel Véron i Guy Matzen. "Therapy modifies cystine kidney stones at the macroscopic scale. Do such alterations exist at the mesoscopic and nanometre scale?" Journal of Applied Crystallography 47, nr 2 (28.03.2014): 719–25. http://dx.doi.org/10.1107/s1600576714004658.
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With an incidence of 1:7000 births, cystinuria, the most frequent cause of stone formation among genetic diseases, represents a major medical problem. Twenty-five cystine stones randomly selected from cystinuric patients were investigated. From a crystallographic point of view, cystine stones are composed of micrometre size crystallites, which are made up of an aggregation of nanocrystals. Through scanning electron microscopy, the morphology and size of the crystallites have been described, while the size of the nanocrystals was investigated by means of powder neutron diffraction. Powder neutron diffraction analysis and/or scanning electron microscopy examination of cystine stones provide evidence that usual alkalinization by sodium bicarbonate associated with high diuresis significantly reduces the size of both nanocrystals and crystallites, while for other treatments, including alkalinizing drugs and thiol derivatives, the data suggest mainly changes in the topology of crystallites. Alkalinization with sodium bicarbonate affects cystine kidney stones at the mesoscopic and nanoscopic scales, while other medical treatments only alter their surface. Such an approach may help to assess the interaction between drugs and cystine stones in cystinuric patients.
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Singh, Manager Rajdeo, i Rajendra Yadav. "Formation of Calcium Oxalate Patinas as Protective Layer on Basaltic Stone Surfaces of 17th Century Raigad Hill Fort, India". Heritage 6, nr 7 (14.07.2023): 5374–92. http://dx.doi.org/10.3390/heritage6070283.
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This work reports calcium oxalate film formation on basaltic stone surfaces of the 17th-century western India Raigad Hill Fort. Nine stone samples extracted from the exterior surfaces of different historical structures of the fort were investigated under FTIR, optical microscopy, XRD, and SEM-EDX. The FTIR spectroscopy revealed intense peaks for Ca-oxalate patinas on basaltic stone surfaces. Observation under optical microscopy clearly showed milky white oxalate films, and peaks for crystalline calcium oxalate, including rock silicates, were prominently observed through XRD investigations. The surface morphology, the origin of the oxalate film, and the state of conservation of the basalt rock were investigated through SEM-EDX. The massive structures at Raigad, at a height of about 800 m, have hardly been chemically cleaned or coated with preservatives in the past. The presence of organic filaments in SEM photomicrographs indicated the biological origin of the oxalate patina due to the thick growth of microbiota on the monument stone during very heavy monsoons. The oxalic acid secreted by microbes dislodged the Ca-rich plagioclase of the stone, ensuring Ca-ions’ availability for film formation. The optical and mineralogical analyses suggest that the film is not the result of simple deposition but of the surface transformation of basaltic stone.
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Kustov, Andrey V., Boris D. Berezin i Vyacheslav N. Trostin. "The Complexon−Renal Stone Interaction: Solubility and Electronic Microscopy Studies". Journal of Physical Chemistry B 113, nr 28 (16.07.2009): 9547–50. http://dx.doi.org/10.1021/jp901493x.
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Germinario, Luigi, i Ákos Török. "Surface Weathering of Tuffs: Compositional and Microstructural Changes in the Building Stones of the Medieval Castles of Hungary". Minerals 10, nr 4 (21.04.2020): 376. http://dx.doi.org/10.3390/min10040376.
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Volcanic tuffs have a historical tradition of usage in Northern Hungary as dimension stones for monumental construction, Ottoman architecture, common dwellings, etc., admirable at its best in the medieval castles of Eger and Sirok. This research explores tuff deterioration in the castle walls, dealing with the mineralogical composition, microstructure, trace-element geochemistry, and microporosity of the surface weathering products and the near-surface stone substrate. The classic microscopic and mineralogical techniques–optical microscopy, SEM-EDS, and XRD–were supported by ICP-MS and nitrogen adsorption analyses. The textures and mineral assemblages of the tuffs are partly diverse, and so are the weathering characteristics, although including common features such as secondary crystallization of gypsum, swelling clay minerals, and iron oxides-hydroxides; deposition of airborne pollutants, i.e., carbon particles and heavy metals; formation of crusts and patinas; decreased surface microporosity. Nonetheless, the entity of deterioration varies, in relation to air pollution–involving changing emissions from road and rail transport–and the specific tuff texture, porosity, and durability–affecting pollutant absorption. The studied stone monuments offer the possibility to examine materials with analogue composition and petrogenesis but utilized in different environmental contexts, which allow pointing out the environmental and lithological constraints and cause-effect relationships related to surface weathering.
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Petcu, Cristian, Elvira Alexandrescu, Adriana Bălan, Maria Antonia Tănase i Ludmila Otilia Cinteză. "Synthesis and Characterisation of Organo-Modified Silica Nanostructured Films for the Water-Repellent Treatment of Historic Stone Buildings". Coatings 10, nr 10 (21.10.2020): 1010. http://dx.doi.org/10.3390/coatings10101010.
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This study presents the facile sol-gel synthesis of nanostructured coatings for use in water-repellent treatment of travertine stone. The synthesized materials combine surface roughness characteristics with particular chemical compositions to give different hydrophobicity results. The influence of the silica particle coating precursor on the hydrophobicity of the polymeric film was investigated, and the octyl-modified silane was selected for further fabrication of the hybrid coatings. The water repellent properties, together with composition and structural properties of the silane-based hybrid material were measured on model glass surface. The coating with the best characteristics was subsequently deposited onto the travertine stone. The potential applicability of the nanostructured material was evaluated considering both the properties of the coating film and those of the travertine stone subjected to the treatment. The surface texture of the film, water repellent properties and uniformity were determined using scanning electron microscopy, atomic force microscopy, dynamic light scattering and contact angle measurements. The coating’s potential for use in stone conservation was evaluated by assessing its impact on the stone’s visual aspect. All the results obtained from the different types of analyses showed that the octyl-modified silica nanostructured material was highly hydrophobic and compatible both with the travertine stone and with the requirements for use on cultural heritage monuments.
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HU, Jianhua, Fengwen Zhao, Qifan Ren, Ye Kuang, Tan Zhou i Zhouquan Luo. "Microscopic characterization and strength characteristics of cemented backfill under different humidity curing conditions". Royal Society Open Science 6, nr 12 (grudzień 2019): 191227. http://dx.doi.org/10.1098/rsos.191227.
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Under different exploitive conditions, the humidity levels of the backfill stopes are not the same. Humidity greatly affects the strength and microscopic characterization of the backfill. Cemented paste backfill (CPB) specimens were cured using 0, 30, 70% and standard curing (20°C, 99%) under four different humidity conditions. At 28 days, nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM) techniques were used to obtain the microscopic features of the CPB specimens. The relationships between the permeability and uniaxial compressive strength (UCS) of the CPB specimens, and the microscopic characteristics of the CPB specimens, were established. The results showed the following: (i) The permeability of the CPB had an exponential functional relationship with its stone powder content. (ii) The stone powder content of CPB and the peak area of the T 2 spectrum are negatively correlated with the UCS. However, there was a T 2 peak area corresponding to the worst UCS with the same stone powder content. (iii) The peak area of the T 2 spectrum showed that the proportion of area of a small pore size was more than 80%, indicating that the pore size was mainly small. The pore diameter of small pores was linearly and inversely proportional to the UCS of the specimens. It can be found that the factors affecting the strength characteristics of CPB include not only the stone powder content, but also the curing conditions of different humidity.
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Chen, You Zhi, Fang Xian Li i Bing Bo Xu. "Use of Clayish Crushed Stone for Production of Aerated Concrete". Key Engineering Materials 302-303 (styczeń 2006): 269–74. http://dx.doi.org/10.4028/www.scientific.net/kem.302-303.269.
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Aerated concrete is a new type of building materials. Clayish crushed stones are regarded as solid waste disposals in China. This paper reports the research outcomes of an experimental study on using clayish crushed stone for the production of aerated concretes of B05 and B06 grade. Hydro-thermal synthesis reaction, mixing proportions, gas-forming and their influences on the concrete performance are investigated. Proper mixing proportions and some important technical parameters are proposed for material design. The microstructure of aerated concrete made with clayish crush stone is analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that the hydration products of clayish aerated concrete are composed of poor crystallized C-S-H (B), blade- and needle-shaped Tobermorite and a small amount of granular Hydrogarnet. A homogeneous and densified microstructure was obtained in the aerated concretes with negligible amount of clay after the hydro-thermal reaction in the mixture.
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Rodrigues, Alexandra, Bruno Sena da Fonseca, Ana Paula Ferreira Pinto, Susana Piçarra i Maria de Fátima Montemor. "TEOS Nanocomposites for the Consolidation of Carbonate Stone: The Effect of Nano-HAp and Nano-SiO2 Modifiers". Materials 15, nr 3 (27.01.2022): 981. http://dx.doi.org/10.3390/ma15030981.
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This study aimed at evaluating the effect of hydroxyapatite (HAp) nanosized structures and nanoparticles of hydrophilic silica as modifiers of both acid- and alkaline-catalysed tetraethoxysilane (TEOS)-based products for the consolidation of carbonate stones. Their initial effectiveness and some compatibility aspects were assessed in a porous limestone (sound and artificially aged Ançã stone samples) and two types of treatment (capillary absorption and brushing). The studied products were examined by scanning electron microscopy (SEM) and micro-Raman spectroscopy. Their depth of penetration and strengthening effect were evaluated through drilling resistance. Their action on the substrate was also further assessed by non-destructive methods based on colour variation and Shore-D hardness. Treated stone samples were dissimilarly affected by the tested treatments and exhibited a significant increase in strength with a low risk of over-strengthening. Adequate in-depth penetration patterns, as well as colour compatibility with the substrate were obtained with some of the prepared formulations through two types of treatment, both in sound and aged stone samples. The potential most effective treatments with the lowest colour change were obtained with the acid-catalysed TEOS-based products modified with HAp nanosized structures.
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Stagno, Valeria, Alessandro Ciccola, Roberta Curini, Paolo Postorino, Gabriele Favero i Silvia Capuani. "Non-Invasive Assessment of PVA-Borax Hydrogel Effectiveness in Removing Metal Corrosion Products on Stones by Portable NMR". Gels 7, nr 4 (14.12.2021): 265. http://dx.doi.org/10.3390/gels7040265.
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The cleaning of buildings, statues, and artworks composed of stone materials from metal corrosion is an important topic in the cultural heritage field. In this work the cleaning effectiveness of a PVA-PEO-borax hydrogel in removing metal corrosion products from different porosity stones has been assessed by using a multidisciplinary and non-destructive approach based on relaxation times measurement by single-sided portable Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy—Energy Dispersive Spectroscopy (SEM-EDS), and Raman Spectroscopy. To this end, samples of two lithotypes, Travertine and Carrara marble, have been soiled by triggering acidic corrosion of some copper coins in contact with the stone surface. Then, a PVA-PEO-borax hydrogel was used to clean the stone surface. NMR data were collected in untreated, soiled with corrosion products, and hydrogel-cleaned samples. Raman spectroscopy was performed on PVA-PEO-borax hydrogel before and after cleaning of metal corrosion. Furthermore, the characterization of the dirty gel was obtained by SEM-EDS. The combination of NMR, SEM-EDS and Raman results suggests that the mechanism behind the hydrogel cleaning action is to trap heavy metal corrosion products, such as Cu2+ between adjacent boron ions cross-linked with PVA. Moreover, the PVA-PEO-borax hydrogel cleaning effectiveness depends on the stone porosity, being better in Carrara marble compared to Travertine.
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Song, Quanshuai, Jianrui Zha, Yulong Bai, Long Chen, Yao Zhang i Hong Guo. "Type and Sources of Salt Efflorescence in Painted Stone Carvings from Pujiang Museum, Sichuan, China". Crystals 13, nr 2 (4.02.2023): 273. http://dx.doi.org/10.3390/cryst13020273.
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Painted stone carvings from Pujiang Museum in Chengdu were excavated from the Ming tombs near to Chengdu Metro Line 7. The Ming burial sites were the eunuch graves of the Shu King, and their tomb was constructed mostly of stone and decorated with paintings and carvings on its surface, which are of great value. However, during their burial, these painted stone carvings suffered significant salt damage. In this research, we performed optical microscope (OM) analysis, Raman spectra (RAM), ion chromatography (IC) analysis, X-ray fluorescence spectroscopy (XRF), X-ray powder diffraction (XRD), and petrographic microscopy (PM) to clarify the salt composition and influence. According to the results, the majority of the salt on the painted layer is CaSO4·2H2O. Before excavation, interaction between acid rain, soil, and groundwater created salt efflorescence on the paint layer’s surface. The deterioration of the paint layer caused by gypsum was divided into two stages: before excavation and during in situ preservation. This research provides a foundation for the removal and prevention of salt efflorescence.
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Putra Gofur, Nanda Rachmad, Aisyah Rachmadani Putri Gofur, Soesilaningtyas Soesilaningtyas, Rizki Nur Rachman Putra Gofur, Mega Kahdina i Hernalia Martadila Putri. "Risk Factor and Pathophysiology of Nephrolithiasis: A Review Article". Journal of Clinical Surgery and Research 2, nr 1 (10.04.2021): 01–04. http://dx.doi.org/10.31579/2768-2757/007.
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Introduction: Nephrolithiasis is a urinary tract stone disease that can be found in the kidneys, ureters, bladder, and urethra. This disease is the three most common diseases in the field of urology besides urinary tract infections and benign prostate enlargement. Kidney stones are the most common, with an estimated lifetime prevalence as high as 15%. Bladder stones have significant morbidity but occur much less frequently than kidney stones. Many factors cause reduced urine flow and cause obstruction, one of which is urine static and decreased urine volume due to dehydration and inadequate fluid intake, this can increase the risk of nephrolithiasis. Low urine flow is a common abnormal symptom. In addition, various conditions that trigger nephrolithiasis such as the composition of various stones are the main factors in identifying the cause of nephrolithiasis. Aims of this article is to review risk factors and pathophysiology of nephrolithiasis. Discussion: Symptoms associated with urinary tract stones depend on the location of the stone, the size of the stone, and any complications that have occurred. Usually, stones in the kidney calyx are asymptomatic. When the stone falls off and descends into the narrow ureter, it becomes symptomatic. Stones generally get stuck in the narrowest part of the ureter, such as the uretero-pelvic junction, when the ureter crosses the iliac vasa, and the uretero-vesical junction. The main symptom of ureteric stones is often an acute onset of pain in the back. This pain can be colicky or not. Colic pain occurs because the peristaltic activity of the smooth muscle of the calical system or ureter increases in an attempt to remove stones from the urinary tract. The increase in peristalsis causes the intraluminal pressure to increase so that there is stretching of the nerve terminals that provide a sensation of pain. The pain can radiate from the pelvis and to the ipsilateral groin. Other symptoms include nausea, vomiting and hematuria. Hematuria can occur macros or microscopy from urinalysis. Hematuria occurs as a result of trauma to the urinary tract mucosa caused by stones. Conclusion: Nephrolithiasis is rock-forming salt reaches a urine concentration that exceeds the equilibrium point between the dissolved component and crystallization occurs. There are several risk factors that nephrolithiasis occurs due to various causes. Therapy and lifestyle changes are interventions that can change risk factors, but there are also risk factors that cannot be changed.
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POVARENNYKH, Mikhail Yur’evich. "The first find of carbon nano- and microtubes and graphite mi- croflakes in carbonate “stone pipes” (island of Crete, Greece)". NEWS of the Ural State Mining University 1, nr 1 (23.03.2020): 118–32. http://dx.doi.org/10.21440/2307-2091-2020-1-118-132.
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Relevance of the work. After finding carbon nanotubes in the so-called silicate “stone pipes” of Dzharakuduk (Uzbekistan) in 2016, we quickly began to accumulate material about discovering carbon nanominerals in similar objects in Kazakhstan, Israel, and India. And after a similar find on the island of Crete (but in carbonate “stone pipes”), it became possible to conduct some generalization for the Mediterranean region. Purpose of the work: identification of the features of the development of carbon nano- and micromineralization in the carbonate “stone pipes” of the island of Crete in comparison with previously known samples from silicate “stone pipes”. Methodology. The samples selected by the authors were studied using optical polarization (ATAMI microscope) and scanning electron microscopy with microdiffraction (SEM LEO SUPRA 50V), differential thermal analysis with mass spectrometric termination (DTA + TG + MS). Results. In the pores and caverns of pyro- and shock-metamorphosed organogenic calcite limestones in the outcrop on the coast of northern Crete (near Malia, Crete, Greece), some fibrous-diverse aggregates of carbon nano- and microminerals (carbon multilayer nano- and microtubes, as well as microflakes of multilayer “graphenes”externally replaced by graphite) with carbonate “stone pipes” almost completely cut off by sea erosion. Conclusions. The first comprehensive study of carbon nano- and micromineralization in the carbonate “stone pipes” of Crete Island allows us to conclude that they are formed as a result of the explosive reaction of silanes that were part of the primary hydrocarbon-like fluid with an aqueous-oxygen atmosphere below the earth’s surface at high temperatures (T> 1250 ° C) and pressure (P> 40 Pa).
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Sangita, Neethu Kesavan i D. B. Vaghela. "Quality Control Evaluation of an Ayurvedic Herbomineral Compound – Mukkadi Bidalaka". Healer 2, nr 1 (3.02.2021): 52–57. http://dx.doi.org/10.51649/healer.20.
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Background: Mukkadi Bidalaka Yoga is a herbomineral compound which is claimed to be effective in Madhumehajanya Timira (Diabetic Retinopathy). In present study, it has been used for Bidalaka Karma.Objective: Present study was designed to watch out on herbal and mineral drugs used in the preparation of Mukkadi Bidalaka Yoga to assess the quality, purity, safety and efficacy of the drug by pharmacognostical (microscopic) study, physicochemical study and chromatographic evaluation. Methods: Pharmacognostical study i.e. morphological characters, organoleptic characters and powder microscopy was done for identification and authentication of all the raw drugs. Physicochemical study and HPTLC of final product were done. Results: Pharmacognostical characters of Mukkadi Bidalaka observed under the microscope were epicarp cells and lignified stone cell of Haritaki, Trichome and lignified scleroids of Bibhitaki, Scleroids, silica deposition of Amalaki, Parenchyma cells and starch grain of Haridra, Prismatic crystal, pitted vessels and fibers of Daruharidra, Cork cells of Nimba, Brown content of Sariva, Trichome, oil globule of Usheera, Stone cells, scleroids, prismatic crystal and fibers of Lodhra, Cork cells , fibers and stone cells of Vata, Parenchyma cells and oil globule of Durva, Border pitted vessels, lignified stone cells oil globule and lignified fiber passing through medullary rays of Chandana, Particles of Girika. Border pitted vessels, lignified fiber, lignified fiber passing through medullary rays of Raktachandana. Pharmaceutical evaluation of Mukkadi Bidalaka Yoga showed results loss on drying at 110C 5.85 % w/w, pH value 6.0, water soluble extract 21.60% w/w, methanol soluble extract 14.28% w/w, Ash value 3% w/w acid insoluble ash 0.39% w/w. High Performance Thin Layer Chromatography result shows 9 spots at 254 nm and 7 spots at 366 nm. Conclusion: Identification and authentication of herbal drug used in the preparation of Mukkadi Bidalaka Yoga was done. Pharmacognostical, physicochemical and HPTLC evaluation of prepared drug has been carried out.
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Pesce, Cecilia, Ligia M. Moretto, Emilio F. Orsega, Giovanni L. Pesce, Marco Corradi i Johannes Weber. "Effectiveness and Compatibility of a Novel Sustainable Method for Stone Consolidation Based on Di-Ammonium Phosphate and Calcium-Based Nanomaterials". Materials 12, nr 18 (18.09.2019): 3025. http://dx.doi.org/10.3390/ma12183025.
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External surfaces of stones used in historic buildings often carry high artistic value and need to be preserved from the damages of time, especially from the detrimental effects of the weathering. This study aimed to test the effectiveness and compatibility of some new environmentally-friendly materials for stone consolidation, as the use thereof has been so far poorly investigated. The treatments were based on combinations of an aqueous solution of di-ammonium phosphate (DAP) and two calcium-based nanomaterials, namely a commercial nanosuspension of Ca(OH)2 and a novel nanosuspension of calcite. The treatments were applied to samples of two porous stones: a limestone and a sandstone. The effectiveness of the treatments was assessed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, ultrasound pulse velocity test, colour measurements, and capillary water absorption test. The results suggest that the combined use of DAP and Ca-based nanosuspensions can be advantageous over other commonly used consolidants in terms of retreatability and physical-chemical compatibility with the stone. Some limitations are also highlighted, such as the uneven distribution and low penetration of the consolidants.
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Shu, Hui, Yujian Song, Qiang Liu i Maobin Luo. "The study of rod-shaped TiO2 composite material in the protection of stone cultural relics". Green Processing and Synthesis 9, nr 1 (2.07.2020): 359–65. http://dx.doi.org/10.1515/gps-2020-0034.
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AbstractTiO2 has many advantages, such as UV resistance, thermal stability, and antibacterial; the attention toward TiO2 composite materials (TCMs) is rapidly increasing in the protection of stone culture relics. An innovative rod-shaped TCM was synthesized in this study. The structure and morphology of TCM were studied by X-ray diffraction and scanning electron microscopy. The acid resistance, weather resistance, hydrophilicity, and photocatalytic performance of TCM had been investigated. The experimental results indicated that TCM has good protection effects. The stone sample treated with TCM has stronger acid resistance and weather resistance, better hydrophilicity, and more excellent photocatalytic activity compared with the untreated stone. More importantly, the stone treated with TCM has better acid resistance and weather resistance than that treated with normal shaped TiO2 materials of the previous study. This work describes an effective way to protect stone cultural relics.
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Mauko, Alenka, Tadeja Muck, Ana Mladenovič i Breda Mirtič. "Porosity of natural stone and use of confocal laser scanning microscopy". Geologija 51, nr 1 (30.06.2008): 77–85. http://dx.doi.org/10.5474/geologija.2008.009.
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