Dispersive Detector Research Articles

Microstructure, wear behaviour and laser ablation behaviour of double glow plasma alloyed Ta[sbnd]W coating

TaW alloy is considered a crucial candidate for barrel protective coatings due to its high melting point, excellent high-temperature performance, and ablative resistance. In this study, TaW coating was deposited on the surface of PCrNi3MoVA gun steel by double glow plasma alloying (DGPA) technique. The morphology, phase structure, wear property, and laser ablation behaviour of the TaW deposited coating was studied and analyzed by means of scanning electron microscope (SEM), energy dispersive spectroscopy detector (EDS), X-ray diffractometer (XRD), ball-on-disk friction test, and laser pulse heating experiment. The results showed that the coating was dense and metallurgically bonded to the substrate. The coating was primarily composed of the α-Ta phase, and W was solidly dissolved in the Ta to form a mutual solution with solid-solution strengthening effect. The wear mechanisms of TaW coating were adhesive wear and oxidative wear. During the laser pulse heating (LPH) process, the transition region, center region, and splash region appeared successively in the ablation area of the coating. After 10 s of ablation, only a region with a diameter of 0.1 mm was penetrated, highlighting the effective protective role of the TaW infiltrated layer on the substrate.

In‐depth study of a speiss/matte sample from Castillo de Huarmey, North Coast of Peru, and its implications for the pre‐Columbian production of arsenic bronze in the Central Andes

AbstractThis study aims to characterize the phase composition and chemistry of the speiss/matte sample from the Metallurgist's Burial at Castillo de Huarmey and to use the information derived from these analyses to infer the temperatures, furnace conditions, and ores associated with the smelting processes, which created the speiss/matte sample. For this purpose, a number of geochemical analyses were performed on the spies/matte fragment: analysis of the general chemical composition (handheld X‐ray fluorescence spectrometry [hhXRF], X‐ray photoelectron spectroscopy [XPS]), analysis of the chemical composition in the micro area (field emission scanning electron microscope with an energy dispersive spectroscopy detector [FE‐SEM‐EDS], field emission electron probe microanalysis [FE‐EPMA]), analysis of the mineral composition (X‐ray diffraction [XRD]), and analysis of the phase composition (Raman spectroscopy). Chemical and mineralogical analyses of the speiss/matte specimen determined that the specimen is composed of distinct arsenide, arsenate, sulfide, and glass phases. During the smelting process, the charge material consisted mainly of Cu, Fe, and As sulfides. Arsenopyrite is the most likely candidate as the mineral source of arsenic. In addition, temperatures of at least 1200°C were achieved during the smelting process, with smelting occurring over a relatively short timeframe given that effective density separation of speiss and matte phases was not achieved.

Diffraction, spectroscopic and microscopic studies of the sand from the amber deposit

QUARTZ sand plays a crucial role in the production of float glass, as it is the main source of silicon dioxide, which is necessary for the production of glass. The research was conducted on two samples of QUARTZ sand from the Oleksiivka amber deposit. The aim of this study was to investigate the morphology and chemical composition of QUARTZ sand samples. The identification methods such as infrared spectroscopy, X-ray diffraction, and electron microscopy with the Energy Dispersive X-ray Spectrometer detector were presented. Applied methods allowed to identify crystalline phases and non-crystalline components of the tested samples.

Effects of Surfactants on the Corrosion Behavior of Aluminum Alloy in Graphene Nanofluid

In this study, the corrosion behavior of aluminum alloy was investigated in graphene nanoplatelet (GNP) nanofluids prepared with different surfactants. The surfactants include sodium dodecylbenzene sulfonate (SDBS), sodium dodecyl sulfate (SDS), Tween 80, and Gum Arabic (GA). The corrosion properties of the alloy in the different GNP nanofluids were evaluated using potentiodynamic polarization tests at room temperature. The surface morphology of the aluminum alloy was analyzed using a scanning electron microscope coupled with an electron dispersive spectroscopy detector. The experimental results revealed that the addition of surfactants improves the resistance of the aluminum alloy to corrosion in the nanofluid. This was attributed to the adsorption of surfactants on the surface of the alloy to form a protective film layer, which reduces moisture permeability and enhances corrosion inhibition. The addition of GA was found to exhibit the highest inhibition efficiency. This was followed by Tween 80, SDS, and SDBS, which contributes the least inhibition. XRD post-corrosion analysis also reveals the presence of aluminum oxide and aluminum hydroxide phases on the surface of electrodes immersed in all the different GNP nanofluids.

Enhanced time resolution with a room-temperature energy dispersive X-ray PIN photodiode detector

Enhanced time resolution with a room-temperature energy dispersive X-ray PIN photodiode detector

Nanoscopic lignin mapping on cellulose nanofibers via scanning transmission electron microscopy and atomic force microscopy

Cellulose has been developed as an alternative to petrochemical materials. By comparison with refined nanofibers (RCNFs), lignocellulose nanofibers (LCNFs) show particular promise because it is produced from biomass using only mild pretreatment. The mechanical properties of LCNFs depend on the contained lignin. However, the microscopic location of the lignin contained in LCNFs has not been determined. Thus, we developed two methods to detect and visualize lignin. One uses a scanning transmission electron microscope (STEM) equipped with an energy dispersive X-ray spectroscopy detector. The other method uses an atomic force microscope (AFM) equipped with a cantilever coated with an aromatic molecule. Both methods revealed that the lignin in LCNFs covers a thin cellulose fiber and is precipitated in a grained structure. In particular, the AFM system was able to determine the nanoscopic location of lignin-rich areas. The present study establishes a strong tool for analyzing the characteristics of lignin-containing materials.Graphical abstract

Influence of Mechanical Torsion on MgCa1 Corrosion Behavior in Simulated Body Fluid

In this paper, the influence of mechanical torsion on the corrosion of MgCa1 alloy in simulated body fluid (SBF) is presented. The corrosion behavior is examined by microstructural observations, including a scanning electron microscope equipped with an energy dispersive spectroscopy detector and electrochemical studies, mainly impedance spectroscopy measurements and polarization curves. The experiments were performed for different time durations (4 h to 8 h) with and without torsion applied (within elastic deformation range in the form of rotary movements) to assign the differences between the corrosion behavior of the samples. It is shown that mechanical torsion (rotations) promotes the leaching of calcium from the grain boundaries in the samples, which decreases the overall alloy corrosion rate. On the other hand, grain boundaries leached out of calcium compounds influence the sample microstructure by enabling cracks formation and propagation. Therefore, rotated samples corroded at a lower rate but were more susceptible to catastrophic failure. It was then concluded that MgCa1 alloy may be a promising biodegradable material for medical implants, however, its durability in SBF with torsion applied is far from being satisfactory.

Influence of Mn content on the magnetic properties of the hexagonal Mn(Co,Ge)2 phase

Herein, we report on the effect of Mn content on the magnetic properties of the hexagonal Mn(Co,Ge)2 with composition Mn36+xCo49-xGe15.This compound was previously described as Mn2Co3Ge (MgZn2-type structure), but later as Mn(Co,Ge)2 with its own structure type, all samples in this work follow the same superstructure model. Samples were synthesized by induction melting, the crystal structures were evaluated using a combination of X-ray diffraction together with scanning electron microscopy equipped and an energy dispersive X-ray spectroscopy detector. The Curie temperature (TC) is shifted towards lower temperature as the Mn content is increased. On the other hand, the spin reorientation temperature (TSRT) increases and the magnetic moment decreases as the Mn content is increased. The magnetocaloric properties were investigated for the x=1 alloy, Mn37Co48Ge15. It was found that the isothermal entropy change is 2 J kg−1 K−1 at room temperature for an applied field of 5 T.

Analysis of Degradation Products of Biodegradable ZnMgY Alloy.

Biodegradable metallic materials are increasingly gaining ground in medical applications. Zn-based alloys show a degradation rate between those recorded for Mg-based materials with the fastest degradation rate and Fe-based materials with the slowest degradation rate. From the perspective of medical complications, it is essential to understand the size and nature of the degradation products developed from biodegradable materials, as well as the stage at which these residues are eliminated from the body. This paper presents investigations conducted on the corrosion/degradation products of an experimental material (ZnMgY alloy in cast and homogenized state) after immersion tests in three physiological solutions (Dulbecco's, Ringer's and simulated body fluid (SBF)). Scanning electron microscopy (SEM) was used to highlight the macroscopic and microscopic aspects of corrosion products and their effects on the surface. An X-ray energy dispersive detector (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) provided general information about the compounds based on their non-metallic character. The pH of the electrolyte solution was recorded for 72 h during immersion. The pH variation of the solution confirmed the main reactions proposed for the corrosion of ZnMg. The agglomerations of corrosion products were on the micrometer scale, mainly oxides, hydroxides and carbonates or phosphates. The corrosion effects on the surface were homogeneously spread, with a tendency to connect and form cracks or larger corrosion zones, transforming the pitting corrosion pattern into a generalized one. It was noticed that the alloy's microstructure strongly influences the corrosion characteristics.

Petrographic studies and mineralogical characterization of the Dellen impactites

AbstractThe impact origin of the Early Cretaceous (140.82 ± 0.51 Ma) 20‐km diameter Dellen structure was proven in the late 60s based on the discovery of planar deformation features (PDFs) in quartz grains. Although decades have passed, impactites found from the crater have not received much attention. Thus, this study provides a detailed petrological and mineralogical description of impactites from Dellen. Impactites were classified based on mineralogical observations using the latest recommendations of nomenclature. The studied samples include impact melt rocks (clast rich, clast poor, and clast free), suevitic impact breccias, shocked and unshocked granite, and a shatter cone. Altogether, 16 samples with different lithologies were studied using a polarization microscope. Selected samples were studied with an energy dispersive spectroscopy detector attached to the scanning electron microscopy. PDFs were indexed using a four‐axis universal stage from seven samples. Selected samples for PDF studies consisted of clast‐rich impact melt rocks (DEL10, DEL13, D99), suevitic impact breccias (DEL14, DEL16, DEL24), and shocked granite target rock (DEL17). A total of 197 PDF sets in 113 quartz grains were studied, and 186 sets resulted in rational crystallographic orientations. Common orientations include π{101̅2}, ω{101̅3}, z{101̅1}, ξ{112̅2}, and {101̅4}. In suevitic impact breccias and impact melt rocks, ballen silica and plagioclase with checkerboard texture were abundant. The petrographic results in Dellen impactites indicate a range of shock pressures from at least 2 to over 60 GPa, based on diagnostic shock metamorphic features in minerals and the occurrence of impact melt rock.

Production and characterization of a bioflocculant produced by Proteus mirabilis AB 932526.1 and its application in wastewater treatment and dye removal

Abstract Microbial flocculants affect the aggregation of suspended solutes in solutions, thus, they are a viable alternative to inorganic and organic synthetic flocculants which are associated with deleterious health problems. Moreover, a potential solution for wastewater treatment. The study aimed to produce and characterize a bioflocculant from Proteus mirabilis AB 932526.1 and apply it in domestic wastewater treatment and dye removal. The bioflocculant was extracted using butanol and chloroform (5:2 v/v). Carbohydrates, proteins, and uronic acid were identified using phenol-sulphuric acid, Bradford, and Carbazole essays. The morphology, crystallinity and elemental composition of the purified bioflocculant were determined using a Scanning electron microscope (SEM), X-ray diffraction analysis and SEM energy dispersive elemental detector (SEM-EDX). The antimicrobial properties and dye removal efficiencies were evaluated. About 3.8 g/L yields of the purified bioflocculant were attained. Chemical composition analysis revealed the presence of 65 % carbohydrates, 10 % proteins, and 24 % uronic acids. The bioflocculant displayed an amorphous and crystalline structure. Bioflocculant further shows some remarkable properties as they can be able to inhibit the growth of both Gram-positive and Gram-negative microorganisms. The removal efficiencies of 85 % (COD), 82 % (BOD), and 81 % (SO4 2−) in domestic wastewater were achieved. Moreover, the high removal efficiency of staining dyes such as methylene blue (71 %), carbol fuchsin (81 %), safranin (83 %), methylene orange (90 %), and Congo red (90 %) were found. The produced bioflocculant can imply industrial applicability.

Biochar from Agro-Forest Residue: Application Perspective Based on Decision Support Analysis

The present work aims at (a) carbonizing agriculture biomass residue; (b) characterizing the obtained biochar; and (c) exploring its potential use for energy/resource recovery purposes. Six types of biomass were carbonized. The biochar was investigated through scanning electron microscopy with energy dispersive X-ray spectroscopy detector, thermogravimetric (TGA), proximate, ultimate, and Brunauer–Emmett–Teller analyses, along with bulk density, pH, electrical conductivity, and salt content measurements. The results served as input data for multi-criteria, multi-objective decision analysis of biochar, aiming to evaluate its best application prospective. The TGA identified two general stages: devolatilization (stage 2: 180–560 °C), and combustion (stage 3: 560–720 °C). The activation energy of stage 2 decreased with an increasing heating rate, but the opposite trend was observed for stage 3. The biochar CO2 adsorption suggested possible applications beyond energy conversion technologies. The decision support analysis revealed that peach stones, cherry stones, and grape pomace biochar achieved the most promising results for all evaluated applications (biofuel; catalyst; CO2 sequestration and soil amendment; supercapacitor) in contrast to colza, softwood, or sunflower husks char.

Energy dispersive x-ray CT using a fixed gantry design for material classification in aviation security x-ray screening

This work presents opportunities and challenges in energy dispersive CT systems for aviation security applications. Current security x-ray scanners use dual-energy systems for threat identification. Dual-energy scanners cannot clearly separate all materials, which results in high false-alarm rates and cause delays for travellers. The development of both new energy dispersive photon counting detectors and associated analysis algorithms allows for improved threat detection by employing energy dispersive scanner systems. The implementation in aviation of such systems as security x-ray scanners also poses several challenges, which are discussed in the paper.

Improved Methodology of Cross-Sectional SEM Analysis of Thin-Film Multilayers Prepared by Magnetron Sputtering

In this work, an improved methodology of cross-sectional scanning electron microscopy (SEM) analysis of thin-film Ti/V/Ti multilayers was described. Multilayers with various thicknesses of the vanadium middle layer were prepared by magnetron sputtering. The differences in cross sections made by standard fracture, focused ion beam (FIB)/Ga, and plasma focused ion beam (PFIB)/Xe have been compared. For microscopic characterization, the Helios NanoLab 600i microscope and the Helios G4 CXe with the Quanta XFlash 630 energy dispersive spectroscopy detector from Bruker were used. The innovative multi-threaded approach to the SEM preparation itself, which allows us to retain information about the actual microstructure and ensure high material contrast even for elements with similar atomic numbers was proposed. The fracture technique was the most noninvasive for microstructure, whereas FIB/PFIB results in better material contrast (even than EDS). There were only subtle differences in cross sections made by FIB-Ga and PFIB-Xe, but the decrease in local amorphization or slightly better contrast was in favor of Xe plasma. It was found that reliable information about the properties of modern nanomaterials, especially multilayers, can be obtained by analyzing a two-part SEM image, where the first one is a fracture, while the second is a PFIB cross section.

High-temperature corrosion data and mechanisms for T122, Super304H and HR3C after 15 years in 1000MW ultra-supercritical power plant

ABSTRACT The high-temperature corrosion of heat-resistant steels T122, Super304H and HR3C used for the inlet of a header in a 1000 MW ultra-supercritical power plant for 15 years was investigated. The steam temperature and pressure were about 610 °C and 28 MPa, respectively. The morphology and phase compositions of the corrosion products formed on the investigated tubes were analysed using X-ray diffraction and a scanning electron microscope with an energy dispersive spectroscopy detector. The results showed that the thickness of the corrosion products on the tube fireside was larger than that on the steam-side of the investigated tubes, which was due to the sulphur in the flue gas. The thickness rank of the corrosion products on the investigated steels was T122 > Super304H > HR3C. Defects including micro-cracks and voids were found in the corrosion products on both sides of the three tubes, which led to the breakaway of corrosion products.

Digital signal processing algorithms for energy dispersive x-rays detectors

Alternative to the traditional analog methods, several digital data preprocessing, shaping and postprocessing techniques have been investigated for the improvement in energy resolution of energy dispersive x-rays detectors. Initial experimental results show that by preprocessing the data, better energy resolution can be obtained at shorter shaping times; thus, it will allow good energy and time resolution at high count rates.

Influence of the shell thickness on the degradation of Ru@Pt core-shell catalysts in PEM fuel cells

Polymer electrolyte membrane fuel cells, which are fueled by reformate, are reliant on highly active, CO tolerant Ru@Pt core-shell anode catalysts. As little is known of the degradation behaviour of these catalysts, the herein presented study investigated membrane electrode assemblies (MEAs), which were stressed under fuel cell relevant conditions, via electrochemical and physical methods. Two catalysts with different shell thicknesses (Ru@1 Pt and Ru@2 Pt) were incorporated in the MEAs to investigate how the shell thickness influences the degradation behaviour. While the MEA incorporating Ru@1 Pt as anode catalyst was higher in performance than Ru@2 Pt MEA under reformate conditions in the beginning, it strongly degraded during stress testing to end up with a lower performance than Ru@2 Pt afterwards. Due to cyclic voltammetry experiments, it was evidenced that for both catalysts Ru was leached from the anode and crossed over to the cathode – but to a significantly lower extent for Ru@2 Pt. This was further quantified by advanced corrected (scanning) transmission electron microscopy coupled with energy dispersive spectroscopy detector. Additionally, due to imaging local degradation effects were observed for the anode, while Ru poisoning the Pt catalyst was found to be a global problem in the cathode.

The Analysis of Red Lead Endsheets in Rare Books from the Fung Ping Shan Library at the University of Hong Kong

Stored under optimal conditions, paper can last for hundreds of years; however, paper is also susceptible to numerous agents of deterioration as it is primarily made of cellulose fibre derived from plant cell walls. Paper is especially vulnerable under conditions with high temperature and humidity, which together can encourage mould growth and foster insect pests. Pest infestation is a common type of deterioration responsible for significant damage to paper and books. Endsheets prepared with red lead and sewn into traditional Chinese bookbindings are a historical method used to minimise insect damage to books in southern China. Samples of red-coloured papers from the Fung Ping Shan Library at the University of Hong Kong were assessed. Two types of so called wan nian hong papers (萬年紅紙), (1) damaged and (2) undamaged by insects, were analysed with a scanning electron microscope equipped with an energy dispersive X-ray fluorescence detector. The chemical analyses reveal high concentrations of red lead (lead tetroxide, Pb3O4) in the undamaged papers, and only very few traces of lead in the damaged papers. The orange papers with insect feeding tunnels seem to have been only coloured in orange, and not treated with red lead as a biocide. These results are discussed and compared with modern treatment methods in the integrated pest management of books, archive, and library materials in (a) Europe and (b) Asia.

Utilization of Waste Glass in Autoclaved Silica-Lime Materials.

This paper aims to investigate the possibility of using waste glass of different colours as a complete substitute for quartz sand in autoclaved silica–lime samples. On the one hand, this increases the possibility of recycling waste glass; on the other hand, it allows obtaining autoclaved materials with better properties. In this research, reference samples with quartz sand (R) and white (WG), brown (BG), and green (GG) waste container glass were made. Parameters such as compressive strength, bulk density, and water absorption were examined on all samples. The samples were examined using a scanning electron microscope with an energy dispersive spectroscopy detector (SEM/EDS) and subjected to X-ray diffraction (XRD) analysis. The WG samples showed 187% higher compressive strength, BG by 159%, and GG by 134% compared to sample R. In comparison to the reference sample, volumetric density was 16.8% lower for sample WG, 13.2% lower for BG, and 7.1% lower for GG. Water absorption increased as bulk density decreased. The WG sample achieved the highest water absorption value, 15.84%. An X-ray diffraction analysis confirmed the presence of calcite, portlandite, and tobermorite phases. Depending on the silica aggregate used, there were differences in phase composition linked to compressive strength. Hydrated calcium silicates with varying crystallisation degrees were visible in the microstructure image.

Biocompatibility of mesoporous SBA-16/hydroxyapatite nanocomposite and dentin demineralized particles on human dental pulp stem cells.

In the present work, a biomaterial (SBA-16/HA) based on the growth of hydroxyapatite (HA) particles within an organized silica structure SBA-16 (Santa Barbara Amorphous-16) was developed to evaluate its application to act as a porous microenvironment promoting attachment and viability of human dental pulp stem cells of healthy deciduous teeth (SHED). First, SHED were isolated and their phenotypes were evaluated by flow cytometry. The samples of SBA-16/HA were characterized by X-ray diffraction (XRD), small and wide angle X-ray scattering (SWAXS), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) equipped with energy dispersive spectra detector (EDS). Afterward, cells were cultured in the eluates of the above-mentioned biomaterial aged for 24 hr, 7. and 14 days. Bio-Oss® and dentin particles are involved for comparison and cells are cultured in the eluates of these two materials also. Thiazolyl Blue Tetrazolium bromide assay-MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay) was used for the determination of cell viability. The results obtained by all aforementioned characterization methods of SBA-16/HA, revealed a uniform spherical mesoporous structure, an intrinsic characteristic of this material. This material displayed excellent biocompatibility on SHEDs, and even proliferative potential, indicating that SBA-16/HA could potentially serve as a suitable substrate for bone regeneration. Contrary to SBA-16/HA, dentin particles showed low cytotoxicity at all time points, compared to control and Bio-Oss®groups. Our results substantiate the idea that SBA-16/HA has a beneficial effect on SHEDs, thus paving the way toward developing new material for bone replacement.