scholarly journals Post-deposition Weathering of Pb-rich Particles From a Pb-Zn Smelting and Refining Factory Under Semiarid Conditions

2021 ◽  
Author(s):  
Martin Federico Soto-Jiménez ◽  
Sarahi Roos-Muñoz ◽  
Sarahi Soto-Morales ◽  
Laura Elena Gómez-Lizarrága ◽  
Lauro Bucio-Galindo
Keyword(s):  
Electron Microscopy ◽  
Chemical Transformations ◽  
Urban Dust ◽  
X Ray ◽  
Physical Chemical ◽  
The World ◽  
Post Deposition ◽  
Mineral Identification ◽  
Scanning Electron ◽  
Semiarid Conditions

Abstract In this study, urban dust samples were collected at 1 km radius surrounding one of the largest Ag-Cd-Pb-Zn smelting and refining complex in the world (Met-Mex Peñoles), which is in operation in Torreón (North México) since 1901. Metal-rich particles in urban dust were analyzed for elemental composition, and Pb-rich particles were identified, characterized, and analyzed for mineral identification by using conventional techniques such as scanning electron microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and X-ray powder diffraction (XRD). Pb-rich particles showed a variety of sizes and morphologies and different contents of Pb and other elements. Pb-rich particles were related to the fugitive and non-controlled emissions from Met-Mex Peñoles. Galena occurs in individual and metal-rich agglomerate particles. The presence of secondary Pb minerals (e.g., Pb carbonates, Pb sulfate, and Pb oxides) evidenced the weathering in Pb-rich particles and metal-rich agglomerates. Secondary Pb minerals are incorporated in finer particles than original sulfide minerals, and they are also more concentrated in Pb and chemically more available than galena for the environment and humans. Physical-chemical transformations on the weathered Pb-rich particles are increasing the availability and toxicity of lead in the urban dust and the potential impacts on the environment and human health.

scholarly journals Effect of Boron on Microstructure and Microhardness Properties of Mo-Si-B Based Coatings Produced Via TIG Process

2016 ◽  
Vol 61 (3) ◽  
pp. 1515-1520 ◽  
Author(s):  
S. Islak ◽  
C. Özorak ◽  
C. T. Sezgin ◽  
M. Akkaş
Keyword(s):  
Electron Microscopy ◽  
Boron Content ◽  
Medium Carbon Steel ◽  
Inert Gas ◽  
X Ray Diffraction ◽  
Medium Carbon ◽  
X Ray ◽  
Physical Chemical ◽  
Structural Applications ◽  
Scanning Electron

Abstract In this study, Mo-Si-B based coatings were produced using tungsten inert gas (TIG) process on the medium carbon steel because the physical, chemical, and mechanical properties of these alloys are particularly favourable for high-temperature structural applications. It is aimed to investigate of microstructure and microhardness properties of Mo-Si-B based coatings. Optical microscopy (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the microstructures of Mo-Si-B based coatings. The XRD results showed that microstructure of Mo–Si–B coating consists of α-Mo, α-Fe, Mo2B, Mo3Si and Mo5SiB2 phases. It was reported that the grains in the microstructure were finer with increasing amounts of boron which caused to occur phase precipitations in the grain boundary. Besides, the average microhardness of coatings changed between 735 HV0.3 and 1140 HV0.3 depending on boron content.

Electrical Porcelain Containing Ornamental Rock Waste: Microstructural Development

2010 ◽  
Vol 660-661 ◽  
pp. 692-696 ◽  
Author(s):  
M.A. Silva ◽  
J.N.F. Holanda
Keyword(s):  
Electron Microscopy ◽  
The Other ◽  
Electrical Porcelain ◽  
Microstructural Development ◽  
Chemical Transformations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminous Porcelain ◽  
Physical And Chemical ◽  
Scanning Electron

Aluminous electrical porcelains are used in the production of materials of high voltage insulators. The microstructure plays an important role in the performance of electrical porcelain. On the other hand, the porcelain materials undergo a series of physical and chemical transformations during firing. This makes the understanding of their microstructures rather complex. In this work was studied the microstructural development of electrical porcelain containing up to 35 wt.% of ornamental rock waste. The pieces ceramics were pressed at 50 MPa and sintered at 1300 °C. The porcelain pieces were characterized via X-ray diffraction and scanning electron microscopy. The results indicate that the presence of the ornamental rock waste influenced the microstructural development of the pieces of electrical aluminous porcelain.

scholarly journals Advanced Characterization of Organic Matter Decaying during Composting of Industrial Waste Using Spectral Methods

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1364
Author(s):  
Saloua Biyada ◽  
Mohammed Merzouki ◽  
Hamada Imtara ◽  
Mohamed F. Alajmi ◽  
Karima Elkarrach ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Organic Matter ◽  
Microbiological Analysis ◽  
Least Squares Regression ◽  
X Ray Diffraction ◽  
Compost Maturity ◽  
X Ray ◽  
Physical Chemical ◽  
Scanning Electron

To date, compost maturation monitoring is carried out by physical-chemical and microbiological analysis, which could be considered an overweening consumption of time and products. Nowadays, spectroscopy is chosen as a simple tool for monitoring compost maturity. In the present investigation, spectroscopy analysis was performed in the interest of corroborating the compost maturity. This goal was achieved by using the X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. X-ray diffraction analysis showed the presence of the cellulose fraction in compost samples. At the same time, the intensity of pics decreased depending on composting time, thus proving that there was organic matter degradation. Infrared and scanning electron microscopy analysis allow for confirming these results. The correlation between spectroscopies analysis and physical-chemical properties was employed by partial least squares-regression (PLS-R) model. PLS-R model was applied to build a model to predict the compost quality depending on the composting time, the results obtained show that all the parameters analysis are well predicted. The current study proposed that final compost was more stabilized compared with the initial feedstock mixture. Ultimately, spectroscopy techniques used allowed us to confirm the physical-chemical results obtained, and both of them depict maturity and stability of the final compost, thus proving that spectral techniques are more reliable, fast, and promising than physical-chemical analyses.

scholarly journals Characterization and analysis of the mortars in the Church of the Company of Jesus – Quito (Ecuador)

2021 ◽  
Author(s):  
M.Lenin Lara Calderón ◽  
David Sanz Arauz ◽  
Sol López Andrés ◽  
Inés Del Pino Martínez
Keyword(s):  
Electron Microscopy ◽  
Research Team ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Religious Architecture ◽  
World Heritage List ◽  
The World ◽  
The Church ◽  
Scanning Electron

The Church of the Company of Jesus in Quito (1605-1765) is one of the most remarkable examples of colonial religious architecture on the World Heritage List. This church has multiple constructive phases and several interventions with no clear record of the entire architectural site, including the historical mortars. A total of 14 samples of coating mortars inside the central nave were taken, with the protocols suggested by the research team and a comparative sample of the architectural group that does not have intervention. The analysis presented in this paper focuses on mineralogical characterization, semi-quantitative analysis by X-ray diffraction and scanning electron microscopy with microanalysis of the samples. The results showed the presence of volcanic aggregate lime and gypsum, used in lining mortars and joint mortars. Mineralogical and textural composition data have allowed the mortar samples to be relatively dated.

scholarly journals Characterization and Analysis of the Mortars in the Church of the Company of Jesus—Quito (Ecuador)

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 781
Author(s):  
M. Lenin Lara ◽  
David Sanz-Arauz ◽  
Sol López-Andrés ◽  
Inés del Pino
Keyword(s):  
Electron Microscopy ◽  
Research Team ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Religious Architecture ◽  
World Heritage List ◽  
The World ◽  
The Church ◽  
Scanning Electron

The Church of the Company of Jesus in Quito (1605–1765) is one of the most remarkable examples of colonial religious architecture on the World Heritage List. This church has multiple constructive phases and several interventions with no clear record of the entire architectural site, including the historical mortars. A total of 14 samples of coating mortars inside the central nave were taken, with the protocols suggested by the research team and a comparative sample of the architectural group that does not have intervention. The analysis presented in this paper focuses on mineralogical characterization, semi-quantitative analysis by X-ray diffraction and scanning electron microscopy with microanalysis of the samples. The results showed the presence of volcanic aggregate lime and gypsum, used in lining mortars and joint mortars. Mineralogical and textural composition data have allowed the mortar samples to be relatively dated.

Synthesis and Stability of the Strontium Cobaltite Thermally Treated in Air

2019 ◽  
Vol 70 (9) ◽  
pp. 3330-3334
Author(s):  
Alina Melinescu ◽  
Georgeta Velciu ◽  
Virgil Marinescu ◽  
Cristian Hornoiu ◽  
Maria Preda
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Stoichiometric Ratio ◽  
Chemical Transformations ◽  
Vitreous Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

This paper reports, the studies on chemical transformations at thermal treatment of a mixture of SrCO3 and Co3O4 corresponding to stoichiometric ratio of SrCoO3 compound. The mixture of raw materials was prepared by mechanical activation. Thermal analysis, X-ray diffraction and scanning electron microscopy were used for these studies. It was found that SrCoO3 forms at 930oC but is not stable and turn immediately into Sr2Co2O5 by eliminating of oxygen. This compound, Sr2Co2O5, is unstable and by increasing of the temperature decomposes in Sr3Co2O6 and cobalt oxide. At temperatures above the 1250oC, the samples melt and Sr3Co2O6 crystallizes from vitreous phase by cooling.

scholarly journals Multi-technique characterization and conservation of an ancient Egyptian fabric from King Khufu first solar ship

2021 ◽  
Author(s):  
Eman Nabil ◽  
Tawfik A. Khattab ◽  
samir kamel
Keyword(s):  
Electron Microscopy ◽  
Optical Microscope ◽  
Elemental Content ◽  
Infrared Analysis ◽  
X Ray ◽  
Ancient Egyptian ◽  
The World ◽  
Ft Ir ◽  
Great Discovery ◽  
Scanning Electron

Abstract Textiles are among the most fragile artefacts in the world. They have been difficult to preserve even in the best circumstances. Herein, we studied an artefact fabric of a special nature in terms of usage. Despite the multiple applications of textiles, the piece understudy is one of the unique pieces that the ancient Egyptian used as fenders for King Khufu first solar boat which is the second-largest discovery in Egypt history. The boat was discovered inside a limestone pit. It was disassembled and arranged in several layers. Four pillows of wrapped fabric were found in the first layer, which were used as boat fenders. This use is in itself a great discovery of the role played by textiles in the manufacture of ancient boats. Thus, we conducted tests and analytical studies of those fenders using a scanning electron microscopy (SEM) and an optical microscope to identify the type and nature of fibers, spinning method and aspects of damage. Both energy-dispersive X-ray (EDX) analysis and infrared analysis (FT-IR) were employed to explore the elemental content of the sample and to study the functional groups of the fabric. These analytical processes were useful in carrying out the restoration and preservation work necessary for the artefact under study.

Preparation of Cu/ZrW2O8 Gradient Films Using Different Targets

2011 ◽  
Vol 66-68 ◽  
pp. 1808-1811
Author(s):  
Xue Yan ◽  
M. Li ◽  
Jun Li ◽  
X. Cheng
Keyword(s):  
Electron Microscopy ◽  
Energy Dispersive Spectrometer ◽  
Rf Magnetron Sputtering ◽  
Argon Atmosphere ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Post Deposition Annealing ◽  
X Ray ◽  
Post Deposition ◽  
Scanning Electron

The Cu/ZrW2O8gradient films have been deposited on silicon substrates by RF magnetron sputtering with copper and compound targets followed by annealing in argon atmosphere at 750 °C for 3 min. The three different compound targets were B1 (nZrO2:nWO3=1:2.2), B2 (nZrO2:nWO3=1:2.5) and B3 (ZrW2O8), respectively. The as-deposited gradient films were amorphous, while a post-deposition annealing at elevated temperature was required for the development of the cubic ZrW2O8. The structure and surface morphology of the gradient films were then studied using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS). The globular and slender rod crystals can be found in annealed films, which are copper and ZrW2O8, respectively. The fine gradient film should be obtained using the target B1.

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