Scanning Electron Microscopy And Energy Dispersive X-ray Spectroscopy Research Articles

Scanning Electron Microscopy Energy-Dispersive X-Ray Spectroscopy Analysis of Catalyst-Coated Porous Transport Layers

The transition of the United States energy infrastructure towards hydrogen energy involves the optimization of proton exchange membrane water electrolyzers (PEMWEs) for reliable hydrogen generation. PEMWE device typically consists of titanium porous transport layer (PTL) and an iridium-based anode catalyst layer. Several directions are being pursued to improve performance and to reduce the costs. To mitigate naturally occurring titanium passivation, protective coatings, typically platinum or other platinum-group metals (PGMs) are commonly applied to the PTLs. The drive to decrease the cost and the use of scarce materials has led to the development of catalyst layers with lower catalyst loadings. Reducing fabrication time and cost as well as increasing efficiency of the anode has led to the investigation of direct application of the iridium-based catalyst onto the Pt-coated Ti PTL. This motivated our investigation of porous-transport electrodes (PTEs) prepared with a variety of deposition methods, using different ink formulations, and targeting different catalyst loadings. There is need to develop a characterization approach that can be used to assess and compare quality of coatings across large parameter space or to monitor quality during production.Several sets of PTEs samples consisting of a titanium porous layer, platinum protective coating and iridium-based catalyst layer were prepared using a wide range of catalyst layer coating methods and parameters, including spray coating, gravure, airbrush and electrodeposition. All samples were characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS) to analyze the elemental composition and assess the distribution of elements of interest (Ti, Pt, and Ir). First, the atomic% of each element was used to calculate elemental ratios for quantitative assessment of the amount of deposited catalyst. However, it is crucial to recognize the limitations of relying solely on this information for assessing catalyst coating since it doesn’t account for heterogeneity of the coatings. Although elemental maps provide valuable insights into spatial distribution, they alone do not offer a complete picture. To better understand the catalyst coating distribution, each individual EDS elemental map was used to calculate the surface area, which served as a measure of PTL area covered by the catalyst. Further, surface area ratios (Pt/Ir) were calculated to determine variations in surface coverage. This poster will highlight differences between fabricated samples and will demonstrate that together, at% and surface area ratio values allow for a comprehensive quantitative assessment of the composition and distribution of catalyst surfaces that were produced through a wide range of fabrication variables. The implementation of proper characterization of these PTEs can help aid future decisions on which parameters should be used moving forward. This approach can also be used for quality control, enabling quick screening of commercially produced samples.

Physicochemical and Biological Changes of Compost Inoculated with Pseudomonas Aeruginosa AAC1 and Rock Phosphate: Implications for P Availability

Phosphorus (P) is an essential nutrient for plant growth, but its availability in soil is often limited. Present study was conducted to design compost enriched with phosphate-solubilizing bacteria (PSB) and rock phosphate (RP). Four compost piles were prepared with RP and 30:1 carbon-to-nitrogen (C: N). Out of these, two piles were inoculated with PSB strain Pseudomonas aeruginosa AAC1 (RP + AAC1) while two piles were left un-inoculated and served as control (RP). The physicochemical assessment of the designed compost revealed that the addition of RP and inoculation of P. aeruginosa AAC1 (RP + AAC1) significantly (p < 0.05) increased the composting temperature (over 58 °C), calcium (36.84%), magnesium (35%) and available P contents (43.50%) indicating the solubilization of inorganic P, Ca and Mg bound phosphates However, the addition did not significantly (p > 0.05) influence the carbon (C), carbon to nitrogen (C/N) ratio, organic matter, and ash content but significantly (p < 0.05) reduced the moisture content (41%) and pH (up to 5.4). After 60 days, all compost piles reached maturity at temperature ranges of 27-30 °C, pH level between 7.2–7.6, and moisture content 31-35%. Scanning electron microscopy and energy-dispersive X-ray spectrometry (SEM-EDS) confirmed the presence of elements including carbon (C), oxygen (O), magnesium (Mg), aluminum (Al), silicon (Si), calcium (Ca), and P (P) in the compost. Microbiological monitoring revealed the survival of P. aeruginosa AAC1 during the composting process even at higher temperatures (∼58 °C). Indigenous bacterial populations were recovered within the range of 109 - 1014 CFUg−1. Compost was also safe in regard to heavy metal concentrations. Thus, the results suggest that combining P. aeruginosa AAC1 and RP in compost can enhance the availability of soluble P, thus serving as an effective phosphatic biofertilizer.

Influence of waste glass on concrete strength and permeability during dry-wet cycles

A series of experiments were carried out to explore the impact of waste glass on the durability of concrete. In this study, waste glass was incrementally incorporated to replace sand as the fine aggregate in creating 240 concrete specimens, with substitution rates of 0%, 10%, 30%, and 50%. The concrete specimens were subjected to early strength testing on the 3rd and 7th day, followed by evaluation of strength and permeability after curing for 28 days with dry-wet cycles. Furthermore, ultrasonic wave analysis was conducted on the waveform, and the concrete’s internal phases and chemical composition were characterized by scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS). The results led to the following observations: (1) The inclusion of glass sand lowered the early compressive strength of concrete, with the lowest drop being 24.78%. However, when it was cured for 28 days and the content of glass sand was not more than 30%, the change rate of its compressive strength was between −2.85% and 3.19%, so it was practically negligible. (2) Glass sand substitution rates ranging from 10% to 30% greatly enhanced the strength of concrete under dry-wet cycles, and the 50% substitution rate significantly improved the permeability properties, although it adversely affected the strength.

SEM-EDS-based rapid measurement and size-fractionated speciation of airborne particulate matter and associated metals utilizing plant leaves.

This study was conducted to assess particulate matter pollution and the accumulation of airborne toxic metals by studying the foliar deposition pattern in an urban environment. To this end, two commonly growing plants (Senna siamea (Lam.) H.S.Irwin & Barneby and Alstonia scholaris (L.) R.Br.) from the busiest traffic squares of the city (Nehru Chowk) in Bilaspur, India, were selected for detailed study. For this purpose, plant leaf samples of both plant species were collected from pollution-affected areas and a reference site (unpolluted) in the city and examined by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS) to estimate the accumulation of PM-bound toxic metals at the leaf surfaces. The results of this study showed that the leaves of both plants accumulate PM in different size ranges. Although both plant leaves showed accumulation of PM from respirable suspended particulate matter (RSPM) to ultra-fine particles (UFPs: < 0.1: less than 100nm) range along with toxic metals, S. siamea retained a higher level of PM than A. scholaris due to better micro-morphological properties on both leaf surfaces. The size of some PM was found to be smaller than the stoma openings. The EDS study proved the presence of harmful airborne toxic metals (Pb, Cd, Cu, Zr, Al, Co, etc.) in these PMs of ambient air. This indicates that toxic metals can enter the leaves through stomatal openings. The results of this study recommended that both plants can be used as a tool to minimise PM pollution.

Isolation of Arborescin from Artemisia absinthium L. and Study of Its Antioxidant and Antimicrobial Potential by Use of In Vitro and In Silico Approaches

This study focused on developing an innovative, straightforward, and economical method utilizing a mixture of readily available solvents to extract arborescin (C2OH2OO8) crystals from Artemisia absinthium L. (A. absinthium). The structural elucidation and characterization were conducted using a suite of techniques including IR spectroscopy, CNHSO elemental analysis, scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), and mass spectroscopy (MS). Density functional theory (DFT) calculations were employed to determine the molecular properties. Antioxidant activity was measured using the DPPH radical scavenging assay and the β-carotene bleaching test. Antimicrobial efficacy was assessed against four bacterial strains and three fungal strains. The molecular docking approach was employed to predict the probable binding patterns and affinities of arborescin with specific target biomolecules. Employing an array of analytical techniques, examination of the isolated crystal from A. absinthium. led to its comprehensive structural elucidation. IR spectroscopy revealed the presence of distinctive functional groups, including a carbonyl group within the γ-lactone and an epoxy group. CNHSO elemental analysis verified that the crystal contained only carbon, hydrogen, and oxygen, a finding corroborated by SEM-EDS analysis, consistent with the molecular structure of arborescin. Additionally, mass spectrometry confirmed the identity of the compound as arborescin, with a molecular ion with a mass m/z = 248. Quantum-Chemical Descriptors revealed that arborescin is resistant to elementary decomposition under standard conditions. Although arborescin demonstrates a relatively low antioxidant capacity, with an IC50 of 5.04 ± 0.12 mg/mL in the DPPH assay, its antioxidant activity in the β-carotene bleaching test was found to be 3.64%. Remarkably, arborescin effectively inhibits the growth of Staphylococcus aureus and Listeria innocua at low concentrations (MIC = 166 µg/mL). Additionally, it exhibits significant antifungal activity against Candida glabrata, with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 83 µg/mL and 166 µg/mL, respectively. In this study, arborescin exhibited a robust docking score of −8.1 kcal/mol, indicating a higher affinity compared to ciprofloxacin. This suggests that arborescin has significant potential as a potent antibacterial agent.

Effect of Ca content on the synthesis and properties of FA-GGBFS geopolymer: Combining experiments and molecular dynamics simulation

The elemental components in the precursor of geopolymers are different, and their mechanical properties are also different. As one of the major influencing factors, calcium content is worth further research and exploration. This paper aims to explore the impact of calcium content on fly ash (FA)-ground granulated blast furnace slag (GGBFS) geopolymer in a comprehensive and multi-scale manner through various research methods such as indoor experiments, microscopic experiments, and molecular dynamics simulations. Using GGBFS as the main source of calcium content in geopolymers, different calcium content samples were prepared by adjusting the GGBFS content. The consistency, setting time, compressive strength, flexural strength, elastic modulus, self-shrinkage value, and dry-shrinkage value of the test blocks were tested at corresponding ages. Analyze its microscopic characteristics through scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS). Finally, the structural models of four geopolymer gels with different Ca contents were constructed, and the mechanism of calcium influence was further characterized from the atomic level. The results indicate that an increase in calcium content is beneficial for the rapid hardening of geopolymer mortar, with varying degrees of increase in compressive strength, flexural strength, and elastic modulus. However, with the increase in calcium content, shrinkage is greater, which may lead to durability drawbacks such as cracking in practical engineering. Therefore, the calcium content should be appropriately controlled. The microscopic morphology showed that the polymer became denser with increasing calcium content, and the Ca/Si ratio in EDS also increases accordingly. Molecular dynamics simulation results also show that Ca can form Ca–O bonds with distant oxygen atoms, making the gel structure more stable.

Enhanced susceptibility of high-strength fastener nuts to hydrogen-induced stress corrosion cracking

Abstract High-strength HV-fastener sets of dimensions M48 and M64 with property class 10.9 were employed in offshore wind turbine frameworks. The M64 were used in coupling flanges within monopiles. The M48 were employed in another offshore wind farm and encountered natural weathering. In both installations, time-delayed fractures of the nuts were observed. Owing to the presence of macroscopically visible corrosion products, hydrogen-induced stress corrosion cracking (Hi-SCC) was established as the probable cause of failure. However, a nut fracture in a properly pre-tensioned bolt assembly is atypical since the stresses in the bolt threads are higher than those in the nuts. Based on the Hi-SCC theory, the fracture should occur at the most stressed component, which is the bolt. During the root cause analysis, extensive examinations were conducted to determine the cause of the nut fractures. The focus was on investigating whether the nut material was more prone to Hi-SCC than the bolt material. The examination program included scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM-EDS) analysis of the fracture surfaces, optical microscopy of microspecimens, mechanical tests, and stress rupture tests of hydrogen-charged specimens. While the results suggest that the tested nuts comply with the requirements of the applicable standards regarding material properties, they also reveal that the nut material is, despite its lower tensile strength, significantly more susceptible to Hi-SCC than the bolt material. Therefore, a direct relationship between material susceptibility to Hi-SCC and the tensile strength, as standards and guidelines imply, is not given.

The Effects of Reusing Cobalt-Chromium Alloy Powder on Its Mechanical Properties and Grain Size: An In Vitro Study.

To characterize material changes that may occur in virgin cobalt-chromium (Co-Cr) alloy powder when it is blended with alloy powders that have been reused multiple times. Initially, 20 kg of virgin Co-Cr powder was loaded into a laser-sintering device. The tensile test specimens were fabricated in the first (Group 1), fourth (Group 2), seventh (Group 3), tenth (Group 4), and thirteenth (Group 5) production cycles (N = 15). Prior to fabricating the specimens, powder alloy samples were collected from the powder bed for analysis. The tensile strength, elastic modulus, and percent elongation were calculated with tensile testing. Scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM/EDS) and laser particle size distribution (LPSD) were used to analyze the alloy powder samples. The fracture surface of one tensile test specimen from each group was examined via SEM/EDS. One-way ANOVA followed by Dunnett T3 test was used for statistical analysis (α = .05). No difference was observed between groups in terms of tensile strength. A statistically significant difference was observed between Groups 1 and 2 in terms of percent elongation. Groups 2 and 4 were statistically significantly different in terms of both elastic modulus and percent elongation (P ≤ .05). SEM images of the powder alloy showed noticeable differences with increasing numbers of cycles. SEM images and the EDS analysis of the fractured specimens were in accordance with the strength data. Reusing Co-Cr alloy powder increased the particle size distribution. However, there was no correlation between increased cycle number and the mechanical properties of the powder.

Manufacturing technique analysis of Early Harappan painted pottery from the Jhang Bahatar Site, Pakistan, by using a multi-analytical approach

Only a limited number of scientific or technological studies regarding Harappan pottery have been conducted so far. To address the knowledge gap, this study investigates the raw materials and manufacturing techniques evidenced in the painted pottery sherds excavated from the Jhang Bahatar site, Pakistan of the late period of early Harappan culture (also identified as the Kot Diji period 2800-2600BC). This study employs a variety of integrated analytical methods including production process observation, X-ray Fluorescence (XRF), X-ray Diffraction (XRD) and Scanning Electron Microscopy, and Energy Dispersive X-ray spectroscopy (SEM-EDS). The investigation revealed that the raw materials in the pastes used to manufacture these painted potteries are common fusible clay characterized by minimal levels of silicon oxide and alumina and elevated levels of flux oxide. The pottery was decorated with an initial basecoat of ochre consisting of hematite (Fe2O3), mixed with pottery paste clay, while the main mineral material of black pigment was magnetite (Fe3O4) and the white pigment was created using dolomite (CaMg (CO3)2).

Enhancing Hydrogen Storage in AZ31 Alloy through Pd/G Composite

In this research, we investigated the catalytic effects of Palladium/Graphene(Pd/G) on AZ31 alloy for hydrogen storage. X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (SEM-EDS) were employed to confirm the homogeneous distribution of AZ31 and observe phase changes after mechanical alloying with the catalysts. The hydrogen storage properties of AZ31 with catalysts were systematically examined, and the time of maximum reaction rate for nucleation was determined using Avarami Plot. The results of the study show that the incorporation of 2% Pd/G resulted in the fastest hydrogen absorption and desorption time, taking 200 seconds to achieve 90% hydrogen storage with a maximum of 6.04 wt%. The corresponding maximum hydrogen desorption occurred in 694 seconds, reaching 6.03 wt%. Consequently, the introduction of 2% Pd/G catalyst proved to be effective in significantly enhancing the hydrogen ab/desorption rates of AZ31 alloy.

Development of polyaniline/chitosan (PANI/CTS) and TiO2-PANI/CTS nanocomposites as anti-corrosion coatings: Synthesis and characterization

Polyaniline/chitosan (PANI/CTS) and TiO2-PANI/CTS nanocomposites were synthesized via in situ oxidative polymerization and characterized by different spectroscopies techniques. The interaction of PANI with the CTS structure and that of the TiO2 nanoparticles with the PANI/CTS copolymer matrix were confirmed by Fourier transform infrared spectroscopy (FT-IR). X-ray diffraction (XRD) analyses of the synthesized nanocomposites show a crystalline structure like their base materials (CTS, PANI and TiO2). The incorporation of PANI, CTS, and TiO2 in the formation of nanocomposites was confirmed by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS). Thermogravimetric and differential scanning calorimetry (TGA and DSC) analyses indicate that the PANI/CTS and TiO2-PANI/CTS nanocomposites present greater resistance to thermal decomposition in relation to the CTS and PANI polymers, as well as the highest glass transition temperature (Tg). The anti-corrosion coatings were made by mixing the polymers and synthesized nanocomposites in an alkyd resin (AR) and deposited on 1018 carbon steel and evaluated in 3.5 wt% NaCl solution by linear polarization and electrochemical impedance spectroscopy (EIS) techniques. The best performance against corrosion was observed for the coating made from TiO2-PANI/CTS, since it shows the noblest values in potential, as well as the highest protection efficiencies, even after its immersion for 30 days, which is attributed to the high degree of cross-linking that the nanocomposite has, forming a dense protective film on the steel surface.

Influence of partial substitution of metakaolin by palm oil fuel ash and alumina waste ash on compressive strength and microstructure in metakaolin-based geopolymer mortar

Geopolymer is recognized as an alternate binder that compounds silica-rich and alumina-rich materials as raw materials and is produced by alkaline activation. In general, biomass ashes in particular for palm oil fuel ash (POFA) is an ideal starting material on the grounds of its high silica concentration, while industrial by-products, especially alumina waste (AW) is also employed as starting material due to its high alumina content. The objective of this research is to address the effects on the compressive strength and also the microstructure of metakaolin-based geopolymer mortar studied through the adaptability of the substitution of metakaolin (MK) by POFA and AW. In order to investigate the effects of POFA and AW substitution on the polymerization reaction and its outcomes, metakaolin-based geopolymers were produced. The most recent data suggests that POFA and AW probably serve as feedstocks for geopolymers with a little strength reduction. The partial substitution of MK by POFA reduces the polymerization reaction rate while maintaining the same water/binder ratio. However, because of the long-lasting polymerization reaction, it is still obtainable to reach a significant degree of polymerization reaction and also provides a comparable 28-day curing age compressive strength for 20 % replacement of MK by POFA. Considering 10 % substitution of POFA by AW, it results in 22.08 % improvement in the compressive strength after 28 curing days. On top of that, the compressive strength development of the geopolymer sample was investigated using scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM/EDS), x-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). It was discovered that the density and the compressive strength were induced by the particle morphologies, the surface area of POFA and AW, and the chemical composition as a result of the geopolymerization.

Removal of Pharmaceuticals from Water Using Laccase Immobilized on Orange Peels Waste-Derived Activated Carbon

The ongoing discharge of containments into the environment has raised concerns about the potential harm they pose to various organisms. In the framework of eliminating pharmaceutical chemicals from aqueous solutions, enzymatic degradation by laccase is an environmentally friendly option. In this investigation, laccase immobilized on biochar derived from agricultural waste (orange peels, OPs) was used for the first time to remove carbamazepine and diclofenac from aqueous media. Different characterizations, such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), X-Ray diffraction (XRD), specific surface area (SBET), Boehm titration, proximate and ultimate analysis, as well as the point of zero-charge (pHPZC) analysis, were used in this study. The immobilization of laccase results in enhanced stability with respect to storage, temperature, and pH compared to laccase in its free form. The findings showed that the ideal conditions for immobilization were a pH of 4, a temperature of 30 °C, and a laccase concentration of 4.5 mg/mL. These parameters led to an immobilization yield of 63.40%. The stability of laccase immobilized on biochar derived from orange peels (LMOPs) was assessed over a period of 60 days, during which they preserved 60.2% and 47.3% of their initial activities when stored at temperatures of 25 °C and 4 °C, respectively. In contrast, free laccase exhibited lower stability, with only 33.6% and 15.4% of their initial activities maintained under the same storage conditions. Finally, the use of immobilized laccase proved to be effective in eliminating these pollutants in up to five cycles. Upon comparing the two systems, namely LMOPs and modified orange peels (MOPs), it becomes apparent that LMOPs exhibit an estimated 20% improvement in removal efficiency. These results affirmed the viability of activated carbon derived from OPs as a cost-effective option for immobilizing laccase. This approach could potentially be further scaled up to effectively eliminate organic pollutants from water sources.

Effect of sulfidization on the surface property and flotation behavior of heterogenite

Heterogenite is an important cobalt oxide mineral, however, few investigations on the surface properties and flotation recovery of heterogenite were conducted. In this study, the effect of sulfidization on the surface property and flotation behavior of heterogenite was studied for the first time, using X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FT-IR) analysis, zeta potential measurements, adsorption amount tests, and micro-flotation experiments. Micro-flotation experiments proved that the flotation recovery of heterogenite is quite difficult. Zeta potential and sulfur ions adsorption tests proved that sulfur could be adsorbed on the surface of heterogenite, but the adsorption amount was very limited, and FT-IR indicates that the adsorption of PAX was also enhanced after sulfidization. XPS and SEM-EDS analysis further showed that the high O/Co ratio, special micromorphology, and Co3+ sites with strongly oxidizing properties on the surface heterogenite hinder the adsorption of sulfur ions being unfavorable sulfidization, which might be the reason why it is difficult to benefit heterogenite. The results are of far-reaching significance for deepening the understanding of the flotation behavior of heterogenite and taking corrective measures to recover this type of cobalt oxide ore.

The effect of 2% chlorhexidine iontophoresis on dentin sealing ability of etch-and-rinse adhesive: An in vitro study

Background/purposeIontophoresis could enhance the delivery of chlorhexidine into oral tissue. This study aimed to determine the effect of 2% chlorhexidine iontophoresis (CHI) on the sealing ability of etch-and-rinse adhesive in human dentin using hydraulic conductance (HD) measurement, scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM-EDS). Materials and methodsThirty-nine sound dentin specimens were prepared from 39 extracted intact third molars. Thirty specimens were used for HD measurement and randomly divided into 3 equal-sized groups; (1) No chlorhexidine treatment (control), (2) passive chlorhexidine treatment (CHT) and (3) CHI on acid-etched dentin. Each dentin surface was treated with etch-and-rinse adhesive. HD of each specimen was measured before treatment, after immediate bonding and after 14 days. The other 9 specimens were subjected to SEM-EDS analysis of the acid-etched dentin and the dentin treated with CHT and CHI. ANOVA test and Student-Newman-Keuls method were used for statistical analysis. ResultsAfter bonding, there was no significant difference in percentage decrease of HD among the treatment groups (P > 0.05). After 14 days, CHI and CHT groups had greater percentage decrease of HD than the control (P < 0.001 and P = 0.009, respectively). Under SEM-EDS analysis, acid-etched dentin with CHI presented opened dentinal tubule orifices and more chlorhexidine precipitates on dentin than the dentin with CHT, which strongly related to a higher percentage of chloride ions on the CHI dentin surface (P < 0.001). ConclusionThe use of CHI on acid-etched dentin had a positive effect on dentin sealing ability of etch-and-rinse adhesive.

Design of symmetric supercapacitor from biowaste derived carbon for flashlight applications with superior cycle’s stability

Extraction of biodiesel from Pongamia pinnata seeds is a vital “Green” synthesis process which is reliable, sustainable, and eco-friendly. The cake obtained during this process is generally utilized as a fertilizer and rich in carbon & nitrogen content. In the present work, initially the material was subjected to carbonization process (PC) was activated with three different porogens such as KOH, KCl, K2HPO4 (K+ as common ion) and labeled as PC-1, PC-2 & PC-3 respectively. The physico-chemical properties of all the carbon materials were investigated by various analytical techniques such as Powder X-Ray diffraction (P-XRD), Brunner Emmett Teller (BET), Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy (SEM-EDS), Transmission Electron Microscopy and Selected Area Electron Diffraction (TEM-SAED), & Raman spectroscopy. PC-1 exhibited better electrochemical performance than the other activated carbons (ACs) & PC with specific capacitance (Cs) of 253F/g at 2.5 A/g, retained 75% Cs at the end of 10,000th cycle and 100% coulombic efficiency in 1 M KOH solution. The symmetric supercapacitor coin cell (SSC) using PC-1 (1 M KOH) exhibited a high Cs of 112F/g at scan rate of 2 mV/s, a maximum energy density (ED) of 38.6 Wh/kg and power density (PD) of 9 kW/kg. Interestingly, the coin cell demonstrated a total of 100 k cycles at high current density of 25 A/g with time gap of fifteen days for 50 k cycles. Six SSCs connected in series were successfully used to power up a flashlight with 15 white LED’s (each 4 V) connected in series for 3 min.

The influence of magnetic particle incorporation on bisphenol A removal by β-cyclodextrin-derived sorbent

A novel, biomass-derived hybrid sorbent Ban-CD-EPI-Fe was successfully synthesized in a coprecipitation method, in which β-cyclodextrin copolymerized with banana peel extract and epichlorohydrin was grafted onto an iron oxide surface. The composition, presence of functional groups, morphology, thermal stability, and magnetic properties of the obtained material were characterized by Powder X-Ray Diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy and Energy Dispersive X-Ray Spectroscopy (SEM-EDS), Thermogravimetric Analysis (TGA), and Physical Properties Measurement System (PPMS). The material bearing around 28% of β-cyclodextrin units has mesoporous structure with plate-like morphology and active surface area determined by BET and Langmuir models equal to 38.35 and 53.59 m2 g−1, respectively. The sorption studies aimed to remove an endocrine disruptor – bisphenol A (BPA), from water. The results showed that the time evolution could be fitted with pseudo-second kinetic order with a rate constant k equal to 0.05 g mg−1 min−1. According to the Langmuir isotherm, a monolayer is created during BPA sorption, and the maximum sorption capacity was estimated as 93.5 mg g−1. After BPA sorption, the hybrid material could be easily separated by an external magnet and regenerated under mild conditions keeping its recyclability in at least eight cycles.

Investigation of the Bimodal Leaching Response of RAM Chip Gold Fingers in Ammonia Thiosulfate Solution.

Oxidative thiosulfate leaching using Cu(II)-NH3 has been explored for both mining and recycling applications as a promising method for Au extraction. This study seeks to understand the dissolution behavior of Au from waste RAM chips using a Cu(II)-NH3-S2O3 solution. In the course of this work, bimodal leaching and Au loss were observed in a manner that we have not identified in the literature. Identification of the existence of a specific Au-Ni-Cu lamellar structure in the gold fingers from RAM chips by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS) revealed the possibility of interference between Au recovery and the existence of Cu and Ni. During leaching, the co-extraction of Ni was found to predict a negative impact on the Au recovery, as a result of chemical interactions from the Au-Ni-Cu interlayer. Decopperization as a pretreatment was found necessary to remove the pre-existing Cu and promote Au leaching. As part of the study parameters, such as Cu(II) concentration, aeration rates, thiosulfate and ammonia concentrations, particle sizes, and temperatures, were investigated. A satisfactory Au recovery of 98% was achieved using 50 mM Cu(II), 120 mL/min aeration rate, 0.5 M (NH3)2S2O3, and 0.75 M NH4OH (i.e., AT/AH ratio of 0.67) for 4 h residence time at room temperature (25 °C). However, there were several high recoveries prior to Au loss from the lixiviant. It was revealed that the main cause of lower Au recovery was due to a precipitation or cementation reaction that included a sulfur species formation. Because of the bimodal leaching, a composite response comprised of the time to Au loss and maximum recovery was developed, termed leaching proclivity, to facilitate statistical analysis. Furthermore, this study explores the interactions between Au-Ni-Cu and provides suggestions for improving Au thiosulfate leaching under the interference of co-existing metals from waste PCB materials.

Deposition of GdSmTi Coating for Corrosion Control of SS 316L in Bio-Field

The corporation of rare earth metals (lanthanides series) with other metals gives good properties in different fields, such as protecting the metallic surface from corrosion risk. In this work, the investigation on adding gadolinium (Gd) and samarium (Sm) as rare metals to bio-inert titanium (Ti) as transition metal was done to protect stainless steel (SS 316L) as bio metallic implant which is used in biofield because of its excellent mechanical properties, low costs, biocompatibility, inertness, and mechanical properties, chemical stability, workability, and high corrosion resistance. The corporation was done through coating using direct current (DC) sputtering technique from the target of these metals mixture to measure some properties. The surface characterization by X-ray diffraction (XRD) gave many phases represented by different GdxNiy in addition to the Ni3Ti phase and Ni5Sm phase. The scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS) results showed the distribution of coating metals as a dense thin film with a good ratio of coating metals; this dense film gave lower surface roughness as illustrated through Atomic force microscopy (AFM) examination from 25.20 nm for the uncoated sample to 15.12 nm for the coated sample with a reduction in the hardness from 187 HV for the uncoated sample to 119 HV for the coated sample as well as increasing contact angle test (wettability) from 90° for base stainless steel surface to 117.723° for coated surface, these results enhanced the compatibility with giving good resistance from corrosion test, with achieving protection efficiency equal to 99.02%.

An improved method for feeding ash model compounds to a bubbling fluidized bed – CLC experiments with ilmenite, methane, and K2CO3

AbstractBiomass conversion with carbon capture and storage (Bio‐Energy CCS; BECCS) is one of the options considered for mitigating climate change. In this paper, the carbon capture technology chemical‐looping combustion (CLC) is examined in which the CO2 is produced in a stream separate from the combustion air. A central research topic for CLC is oxygen carriers; solid metal oxides that provide oxygen for the conversion process. Biomass and waste‐derived fuels contain reactive ash compounds, such as potassium, and interactions between the oxygen carrier and the ash species are critical for the lifetime and performance of the oxygen carrier. This work develops and demonstrates an improved method for studying the interactions between ash species and oxygen carriers. The method uses a lab‐scale reactor operating under fluidized conditions, simulating CLC batch‐wise by switching between feed gas. The novelty of the setup is the integrated system for feeding solid particles of ash model compounds, enabling the simulation of ash species accumulating in the bed. Ilmenite is a benchmark oxygen carrier for solid fuel conversion and was used in this study to evaluate the method using K2CO3 as a model ash compound. Experiments were done at 850 and 950°C. Methane conversion in CLC cycles and fluidization was evaluated with gas analysis and pressure drop measurements. Scanning electron microscopy and energy dispersive X‐ray spectroscopy (SEM‐EDS) and X‐ray diffraction (XRD) analysis of bed particles were done after the experiments to establish changes in the morphology and composition of the ilmenite. The method for feeding the ash model compound was concluded to be satisfactory. At 950°C, K accumulated in the particles forming K‐titanates and agglomeration was enhanced with K2CO3 addition. The agglomeration mechanism was solid‐state sintering between the Fe‐oxides forming on the particle surfaces. The bed defluidized at 950°C, but no such effect was seen at 850°C. The method is suitable for studying the Fe‐Ti‐K system with ilmenite and potassium without the influence of other ash species. © 2023 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley &amp; Sons Ltd.