Energy-dispersive Spectroscopy Scanning Electron Microscopy Research Articles

Biosynthesized and chemically synthesized Ag/TiO2 nanocomposites: Effect of reaction parameters on synthesis using watermelon rind extract and comparative analysis

This work synthesized Ag/TiO2 nanocomposite via an aqueous reduction method using a green and chemical reducing agent. Citrullus lanatus (watermelon) rind extract (WMRE) and sodium borohydride (NaBH4) were used as the reducing agents during green synthesis and chemical synthesis, respectively. During green synthesis, a pH of 12, a reaction time of 45 min, and an operating temperature of 100 °C yielded the best visible light activity. The biosynthesized and chemically-synthesized Ag/TiO2 were compared using UV–Vis spectroscopy, X-ray fluorescence spectroscopy (XRF), X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy-scanning electron microscopy (EDS-SEM) and transmission electron microscopy (TEM). Synthesis using WMRE yielded spherical Ag nanoparticles modified on the surface of TiO2 nanoparticles. The Ag nanoparticles had enhanced monodispersity with an average diameter of 7.48 ± 4.06 nm. Therefore, the developed WMRE green synthesis method provides a simple, less chemical-intensive, and effective alternative to chemical synthesis.

Electrospun Polyvinyl Butyral Nanofibers Loaded with Bismuth Oxide Nanoparticles for X-ray Shielding

The combination of electrospun nanofibers and nanoparticles is opening up potential in the field of nanocomposite materials. This paper presents a composite electrospun nanofibrous material for X-ray shielding purposes consisting of a polyvinyl butyral polymer matrix and bismuth oxide nanoparticles. The organic–inorganic composite nanofibers considered in this paper, produced via the ex situ approach, attained a high content of nanoparticles of up to 95 wt %. The high content of nanoparticles inside the composite nanofibers was acquired via the application of the highly productive needleless electrospinning method. The resulting material is flexible and has a high drape and good air and steam permeability. The content of particles in the nanofibers was proved by the thermogravimetric analysis, and the homogeneous distribution of particles inside the nanofibers and within a whole nanofibrous layer was demonstrated via energy dispersive spectroscopy-scanning electron microscopy. In addition, samples of the composite electrospun nanofibers were tested for cytotoxicity, which revealed that the nanofibers were cytocompatible in all concentrations. The radiation attenuation properties of the samples were investigated via X-ray and γ-ray spectral measurements at a narrow beam geometry. The principal experimentally determined quantity for the tested samples was X- and γ-ray attenuation for the considerable energies of the spectra. The mass attenuation coefficients were calculated for the final composite electrospun material, which was supplemented by a composite nanofibrous material covering layer. With respect to photon energies higher than 40 keV, the attenuation coefficients were observed to be comparable with a commercially produced anti-radiation vest, which had a similar mass density as both the final composite electrospun material and the covering layer. Monte Carlo (MC) simulations in the FLUKA code were conducted to determine the photon attenuation for the respective energies in the tested samples. The results were compared to those determined experimentally, and the MC model was verified.

Petrographic Microscopy with Ray Tracing and Segmentation from Multi-Angle Polarisation Whole-Slide Images

‘Slide scanners’ are rapid optical microscopes equipped with automated and accurate x-y travel stages with virtual z-motion that cannot be rotated. In biomedical microscopic imaging, they are widely deployed to generate whole-slide images (WSI) of tissue samples in various modes of illumination. The availability of WSI has motivated the development of instrument-agnostic advanced image analysis software, helping drug development, pathology, and many other areas of research. Slide scanners are now being modified to enable polarised petrographic microscopy by simulating stage rotation with the acquisition of multiple rotation angles of the polariser–analyser pair for observing randomly oriented anisotropic materials. Here we report on the calibration strategy of one repurposed slide scanner and describe a pilot image analysis pipeline designed to introduce the wider audience to the complexity of performing computer-assisted feature recognition on mineral groups. The repurposed biological scanner produces transmitted light plane- and cross-polarised (TL-PPL and XPL) and unpolarised reflected light (RL) WSI from polished thin sections or slim epoxy mounts at various magnifications, yielding pixel dimensions from ca. 2.7 × 2.7 to 0.14 × 0.14 µm. A data tree of 14 WSI is regularly obtained, containing two RL and six of each PPL and XPL WSI (at 18° rotation increments). This pyramidal image stack is stitched and built into a local server database simultaneously with acquisition. The pyramids (multi-resolution ‘cubes’) can be viewed with freeware locally deployed for teaching petrography and collaborative research. The main progress reported here concerns image analysis with a pilot open-source software pipeline enabling semantic segmentation on petrographic imagery. For this purpose, all WSI are post-processed and aligned to a ‘fixed’ reflective surface (RL), and the PPL and XPL stacks are then summarised in one image, each with ray tracing that describes visible light reflection, absorption, and O- and E-wave interference phenomena. The maximum red-green-blue values were found to best overcome the limitation of refractive index anisotropy for segmentation based on pixel-neighbouring feature maps. This strongly reduces the variation in dichroism in PPL and interference colour in XPL. The synthetic ray trace WSI is then combined with one RL to estimate modal mineralogy with multi-scale algorithms originally designed for object-based cell segmentation in pathological tissues. This requires generating a small number of polygonal expert annotations that inform a training dataset, enabling on-the-fly machine learning classification into mineral classes. The accuracy of the approach was tested by comparison with modal mineralogy obtained by energy-dispersive spectroscopy scanning electron microscopy (SEM-EDX) for a suite of rocks of simple mineralogy (granulites and peridotite). The strengths and limitations of the pixel-based classification approach are described, and phenomena from sample preparation imperfections to semantic segmentation artefacts around fine-grained minerals and/or of indiscriminate optical properties are discussed. Finally, we provide an outlook on image analysis strategies that will improve the status quo by using the first-pass mineralogy identification from optical WSI to generate a location grid to obtain targeted chemical data (e.g., by SEM-EDX) and by considering the rock texture.

Wearing Effect of Implant Steel Drills and Tappers for the Preparation of the Bone Osteotomies: An Infrared Thermal Analysis and Energy Dispersive Spectroscopy-Scanning Electron Microscopy (EDS-SEM) Study

Background: The thermal effect correlated with implant osteotomy could produce significant effects on the healing process and fixture osseointegration. The aim of the present investigation was to assess the heat generation and surface wearing of dental implant drills and manual tappers during simulated osteotomies on animal ribs. Methods: Steel drills (20 units per type) and tappers (20 units per type) were evaluated for a total of 30 osteotomies. The infrared thermal analysis was performed at the first and thirtieth osteotomy. The surface alteration and wearing was assessed by energy dispersive spectroscopy–scanning electron microscopy (EDS-SEM) prior to and after use. Conclusions: The drill material produced a non-significant temperature change during bone osteotomy. Lower heating was reported for manual tappers in favor of a manual osteotomy instead rotary instruments.

Study of Microstructure and Mechanical Property Degradation of SA210 A1 Boiler Tube

The comprehension of the microstructure change and mechanical property degradation are of particular importance for assessing the integrity of aging boiler tubes.This paper describes the investigation of microstructure evolution and mechanical property degradation of SA210 A1 steel used in an actual boiler condition. The investigation deals with visual inspection, chemical composition analysis, micrograph study using Energy Dispersive Spectroscopy-Scanning Electron Microscopy (EDS-SEM), tensile test and hardness test. The result showed that the prolonged operating period in the high temperature condition resulted in the reduction of the mechanical properties of the SA 210 A1 steel tube. The study also indicated the presence of the onset of the pearlite disintegration and coagulation, resulted from the microstructure degradation of the aged steel tube after the elevated temperature service in a boiler.

Analysis of Polymer-Biomacromolecule Composites in the Solid-State via Energy Dispersive Spectroscopy-Scanning Electron Microscopy

Analysis of Polymer-Biomacromolecule Composites in the Solid-State via Energy Dispersive Spectroscopy-Scanning Electron Microscopy

High Spatial Resolution EDS Mapping of Nanoparticles at Low Accelerating Voltage

Abstract In conventional energy-dispersive spectroscopy/scanning-electron microscopy (EDS/SEM) analysis, the pear-shaped interaction volume of incident electrons in the bulk sample determines spatial resolution and the actual scope of EDS analysis is usually a few cubic microns. Lowering the accelerating voltage can reduce effectively the interaction volume of the electron beam. In this study, Monte Carlo (MC) simulation was used to analyze effectively the actual interaction between low-energy incident electrons and nanoparticles. MC x ray, a new Monte Carlo program, was used to further simulate EDS mapping of Ni nanoparticles on the top of an Al2O3 matrix at an accelerating voltage of 3 kV, and the theoretical spatial resolution was calculated to be approximately 10 nm. In addition, EDS mapping images of 17-nm Ni nanoparticles were successfully acquired at high spatial resolution similar to the theoretical value by adjusting the operating conditions for SEM-EDS analysis, including the use of immersion objective lens, the removal of electron trap and collimator, and the reduction of working distance as well as detector distance.

Thin BaCe0.8Gd0.2O3 − δ Protonic Electrolytes on Porous Ce0.8Gd0.2O1.9 – Ni Substrates

Thin proton-conducting electrolytes with thickness and a nominal composition were prepared over porous substrates composed of (CGO)–Ni. The fabrication method includes the simultaneous cofiring and solid-state reaction at of three screen-printed layers: mixed conducting anode layer, CGO, and an upper-coated layer. The resulting asymmetric membranes with geometry are gastight. The solid-state reaction resulted in the formation of (i) an electrolyte with large grains and high packing density and (ii) anode layer comprising finely grained and Ni particles with a thickness around . The layer morphology, phase distribution, and lattice composition has been investigated by X-ray diffraction, energy-dispersive spectroscopy scanning electron microscopy, and secondary-ion mass spectrometry. The preparation of the substrate by warm-pressing and tailoring of the porosity and sintering activity are also thoroughly described. DC-electrical conductivity and ac-electrochemical characterization showed that the supported Gd-doped barium cerate electrolyte produced by solid-state reaction has interesting proton-conduction properties for application in solid oxide fuel cells, hydrogen separation, and sensors.

Chemistry of Mg Smectites in Lacustrine Sediments from the Vicalvaro Sepiolite Deposit, Madrid Neogene Basin (Spain)

AbstractThe chemical and structural properties of Mg smectites in the Vicálvaro sepiolite deposit have been studied in detail. The characterization was performed on different size-fractions of selected smectitic samples (5−2 µm; 2−1 µm; 1−0.5 µm; <0.5 µm and <0.1 µm). The chemical compositions of individual particles (5−1 µm) and of bulk undifferentiated fine fractions (1−<0.1 µm) were determined by energy dispersive spectroscopy-scanning electron microscopy and interpreted with the aid of X-ray diffraction (XRD) and infrared spectroscopy (IR) methods. The XRD and IR data demonstrate that all of the Mg smectite materials studied are mainly composed of a complex mixture of stevensite, saponite and mica-type minerals. Although the presence or absence of saponite cannot be confirmed absolutely, stevensite is a significant component of these Mg smectites. This is proven by the calculated layer charge reduction after the Hofmann-Klemen effect. The results are in close agreement with the suggested mechanism of topotactic overgrowth of stevensite on pre-existing phyllosilicate templates. This characterizes clay diagenesis in saline-lake systems.