Elemental Analysis Research Articles

Electrodeposited Zn-Mn on three-dimensional electrodes as anodes in liquid and quasi-solid-state zinc-air batteries

Zinc-air batteries (ZABs) are eco-friendly and sustainable energy storage devices. There are different challenges to overcome in ZABs, where anodic issues such as shape changes, passivation, self-corrosion, and dendrite formation require urgent solutions. In this work, Zn and Zn-Mn alloys were electrodeposited on three-dimensional porous carbon electrodes varying the Mn composition (2, 20 and 40 g L−1) and studying its effect during the operation of a 6 M KOH liquid ZAB and a quasi-solid-state ZAB based on poly(vinyl alcohol)/poly(acrylic acid) PVA/PAA gel polymer electrolyte (GPE). Scanning electron microscopy (SEM) images indicated that Zn and Zn-Mn were deposited as platelet-like bi-dimensional structures. Additionally, the use of 20 and 40 g L−1 of the Mn precursor resulted in larger Zn deposition covering the 3D structure of the carbon paper. Elemental analysis indicated that the Mn content in Zn-Mn was 1.3, 2.4 and 6 %. In the aqueous ZAB, the Zn-Mn with 2.4 % Mn enabled to increase the maximum current density achieving the highest power density of 45 mW cm⁻2. In QSS-ZAB, Zn-Mn at 1.3 and 2.4. % Mn displayed higher stability to recovery after demanding different current densities, while the first anode displayed higher cyclability, presenting a similar round trip after 240 charge/discharge cycles This ZAB was maintained functional during 290 cycles vs. 120 cycles for Zn foil. The rechargeability was improved because of the decrease in Zn dendritic growth and passivation.

Phytochemical composition, simulated digestive bioaccessibility and cytotoxicity of Ficus auriculata Lour. fruits: In vitro and in silico insights

Ficus auriculata Lour. (Moraceae) is an underutilized wild edible fruit widely consumed for its nutritional properties. The present study aimed to determine the phytochemical composition and in vitro antioxidant, enzyme inhibitory, anti-inflammatory and anti-cancerous properties of the F. auriculata fruit extracts through in vitro digestion (oral, gastric and intestinal phases). The extracts were obtained by hot extraction and cold maceration methods using aqueous and methanolic solvents. Major phytoconstituents identified through LC-MS was subjected to molecular docking against the target proteins. The elemental analysis shows the presence of major elements; high levels of total phenolic compounds (124.61 ± 0.82 mg gallic acid equivalent/g), flavonoids (76.38 ± 0.82 mg quercetin equivalent/g), vitamin E (32.48 ± 0.09 mg alpha-tocopherol equivalent/g), and carbohydrate (34.59 ± 0.45 mg glucose equivalent/g) in hot extracted methanolic undigested extract (HEM UD) and high level of total protein (124.71 ± 0.34 mg bovine serum albumin equivalent/g) in cold extracted methanolic undigested fruit extract were found. HEM UD showed high antioxidant activity in 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid), 2,2-diphenyl-1-picryl-hydrazyl, and superoxide radical scavenging assays with IC50 of 53.30 ± 0.57, 80.69 ± 0.12, and 65.47 ± 1.13 μg/mL, respectively. The HEM UD extract also potentially inhibited the enzyme activity of α-amylase, α-glucosidase, tyrosinase, and protein denaturation (IC50 of 67.76 ± 1.22, 83.18 ± 1.23, 87.24 ± 1.15, and 65.76 ± 0.60 μg/mL). The most potent extract (HEM UD) was studied for its anticancer effects by MTT assay against the MCF-7 and HeLa cell lines with the IC50 of 89.80 ± 0.56 and 60.76 ± 0.04 μg/mL, respectively. The LC-MS analysis elucidated ten phytoconstituents. Based on the molecular docking study, querciturone could potentially be an effective constituent in treating diabetes and inflammation-related issues. The findings indicated the ability of F. auriculata fruits as a promising functional food.

Atomic-level insights into CeO2 performance: Chemical interactions in CMP explored through CeO2-SiO2 studies

This study explores the effects of atomic-level factors on the performance of CeO2 when interacting with SiO2 films. It specifically examines how different precursors, the ratio of Ce to OH, and reaction temperatures influence outcomes. Our findings reveal that smaller particles, around 5 nm in size, created using a Ce4+ precursor, are more effective at removing SiO2 films compared to larger, more crystalline particles from a Ce3+ precursor. This is due to their increased interaction with the SiO2 film during the polishing process, challenging the conventional emphasis on mechanical abrasion in chemical mechanical planarization (CMP) and highlighting the crucial role of chemical interactions. Further analysis through FT-IR and TGA-FTIR techniques showed distinct functional group profiles on the ceria surfaces. Ceria derived from Ce4+ exhibited a higher presence of OH and NO3 groups, enhancing adsorption capabilities, as verified by CHN analysis. Importantly, first-principles calculations identified these surface groups as key to improving adhesion to SiO2 films. Surfaces of amorphous CeO2, rich in -OH and -NO3 groups, showed significantly higher adhesion levels than their crystalline counterparts, connecting crystallinity to chemical functionality. This new insight leads to the possibility of designing next-generation CeO2 abrasives with increased chemical activity.

Comparative study of metal-organic frameworks synthesized via imide condensation and coordination assembly.

A series of metal-organic frameworks (1-XDI) have been synthesized by imide condensation reactions between an amine-functionalized pentanuclear zinc cluster, Zn4Cl5(bt-NH2)6, (bt-NH2 = 5-aminobenzotriazolate), and organic dianhydrides (pyromellitic dianhydride (PMDA), naphthalenetetracarboxylic dianhydride (NDA), 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (HFIPA)). The properties of the 1-XDI MOFs have been compared with analogues (2-XDI) prepared using traditional coordination assembly. The resulting materials have been characterized by ATR-IR spectroscopy, acid-digested 1H NMR spectroscopy, elemental analysis, and gas adsorption measurements. N2 adsorption isotherm data reveal modest porosities and BET surface areas (30-552 m2 g-1). All of the new 1-XDI and 2-XDI MOFs show selective adsorption of C2H2 over CO2 while 2-PMDI and 2-BPDI exhibit high selectivity toward C3H6/C3H8 separation. This study establishes imide condensation of preformed metal-organic clusters with organic linkers as a viable route for MOF design.

Tuning (Photo)Electronic Properties of an Electron Deficient Porous Polymer via n-Doping with Tetrathiafulvalene.

Charge-transfer complex formation within the pores of porous polymers is an efficient way to tune their electronical properties. Introduction of electron accepting guests to the electron donating hosts to conduct their p-doping is intensively studied in this context. However, the vice versa scenario, n-doping by treating the electron deficient (i.e., n-type) porous polymers with electron donating dopants, is rare. In this work, synthesis of an n-type phenazine based conjugated microporous polymer and its exposure to strong electron donating tetrathiafulvalene (TTF) dopants are presented. The fundamental physical characterizations (e.g., elemental analysis, gas sorption) showed that the vacuum impregnation technique is a good approach to load the guest molecules inside the pores. Moreover, the formation of charge-transfer complexes between the phenazine building blocks of the polymeric network and TTF dopants are confirmed via spectral techniques such Fourier transform infra-red, UV-vis, steady-state/time-resolved photoluminescence, and transient absorbance spectroscopies. Effect of the doping to the electronical properties is monitored by employing photoelectrochemical measurements, which showed lower charge-transfer resistivity and nearly doubled photocurrents after the doping. The study is, therefore, an important advancement for the applicability of (n-type) porous polymeric materials in the field of photo(electro)catalysis and organic electronics.

Synthesis of Graphene@C3N4-Cu Beads Nanocomposites and their Antimicrobial Efficacy Against Drug-Resistant Bacteria and Fungi.

Increased intake of drugs worldwide and the subsequent advent of resistance to existing antibiotics have globally threatened health organizations. To combat the problem of these drug-resistant infections, as an alternative approach, graphene (GN)-related nanomaterials have attracted significant interest because of their effective anti-microbial potential. The present study shows the synthesis and characterization of nanocomposite of GN with carbon nitride viz. g- C3N4, g-C3N4-Cu, and GN@g-C3N4-Cu. Further, we investigated the anti-microbial potential of these nanocomposites against strains of Gram-negative and Gram-positive bacteria, viz., a multidrug- resistant strain of Pseudomonas aeruginosa (MDRPA), a methicillin-resistant strain of Staphylococcus aureus ATCC33593 (MRSA), and an azole-sensitive fungal strain (Candida albicans ATCC14053). The morphological characterization of GN@g-C3N4-Cu nanocomposite was executed by scanning electron microscopy, whereas the elemental analysis and their distribution were studied by energy-dispersive X-ray spectroscopy and elemental mapping methods. Furthermore, the anti-microbial and antibiofilm efficacies of g-C3N4, g-C3N4-Cu, and GN@g-C3N4-Cu nanocomposites were evaluated by disc diffusion, two-fold serial micro broth dilution, and 96 well microtiter plate methods. The ternary g-C3N4-Cu@GN, apart from the structures of g-C3N4-Cu, showed big sheets of GN. The observance of C, N, O, and Cu in the elemental analysis, as well as their uniform distribution in the mapping, indicated the successful fabrication of g-C3N4-Cu@GN. GN@g-C3N4-Cu followed by g-C3N4-Cu and (g-C3N4) exhibited significantly higher antimicrobial activity (zone of inhibition from 14.33 to 49.33 mm) against both the drug-resistant bacterial strains and azole-sensitive C. albicans. MICs of nanocomposites ranged from 32 -256 μg/ml against the tested strains. Whereas all three nanocomposites at sub-MICs (0.25 A- and 0.5 A- MICs) showed concentration- dependent inhibition of biofilm formation in MDRPA, MRSA, and C. albicans by allowing 11.35% to 32.59% biofilm formation. Our study highlights the enhanced efficiency of GN@g-C3N4-Cu nanocomposites as potential anti-microbial and antibiofilm agents to overcome the challenges of multi-drug-resistant bacteria and azole-sensitive fungi. Such kind of nanocomposites could be used to prevent nosocomial infections if coated on medical devices and food manufacturing instruments.

Synthesis and Photocatalytic sp3 C-H Bond Functionalization of Salen-Ligand-Supported Uranyl(VI) Complexes

Recent years have seen increasing interest in uranyl(VI) photocatalysis. In this study, uranyl complexes were successfully synthesized from ligands L1–L6 and UO2(NO3)2·6H2O under reflux conditions, yielding products 1–6 with yields ranging from 30% to 50%. The complexes were thoroughly characterized using NMR spectroscopy, single-crystal X-ray diffraction, and elemental analysis. The results indicate that complexes 1–5 possess a pentagonal bipyramidal geometry, whereas complex 6 exhibits an octahedral structure. The photocatalytic properties of these novel complexes for sp3 C-H bond functionalization were explored. The results demonstrate that complex 4 functions as an efficient photocatalyst for converting C-H bonds to C-C bonds via hydrogen atom transfer under blue light irradiation.

Unusually Large Ligand Field Splitting in Anionic Europium(III) Complexes Induced by a Small Imidazolic Counterion.

Luminescent trivalent lanthanide (Ln3+) complexes are compounds of technological interest due to their unique photophysical properties, particularly anionic tetrakis complexes, given their higher stability and emission quantum yields. However, structural studies on the cation-anion interaction in these complexes and the relation of such to luminescence are still lacking. Herein, the cation-anion interactions in two luminescent anionic tetrakis(2-thenoyltrifluoroacetonato)europate(III) complexes with alkylimidazolium cations, specifically 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium are investigated. The Eu3+ complexes were synthesized and characterized by elemental analysis, mass spectrometry, and single-crystal X-ray crystallography, and their luminescence spectra were recorded at 77 K. Quantum chemical calculations were also performed. X-ray crystallography revealed hydrogen bonds between the enolate ligands and imidazolium ring hydrogens. The 1-butyl-3-methylimidazolium complex had two crystallographic Eu3+ sites, also confirmed by luminescence spectroscopy. The 1-ethyl-3-methylimidazolium complex exhibited an unusual 300 cm-1 splitting in the 5D0 → 7F1 transition, as reproduced by ligand field calculations, suggesting a stronger hydrogen bonding due to the smaller substituent. We hypothesize that this strong bonding likely causes angular distortions, resulting in high ligand field splittings.

Evaluation of the effect of self-assembling peptide and fluoride varnish, alone or in combination with laser irradiation, on artificial enamel caries: a SEM/EDS and Micro-CT study.

The aim of this study was to investigate the effect of remineralization agents such as fluoride varnish and P11-4, alone and in combination with Er: YAG laser, on in-vitro hard tissue repair in artificial enamel lesions. A total of sixty enamel surfaces of 4 × 5mm in size were created on both the buccal and lingual sides of thirty extracted wisdom teeth. Remineralization agents were applied to the specimens that were grouped as follows: Group 1, control; Group 2, fluoride varnish (FV); Group 3, P11-4; Group 4, laser; Group 5, laser + FV; and Group 6, laser + P11-4. The fluorescence level was determined with DiagnoDent. The enamel mineral density, area and volume, and caries lesion area and volume were determined with micro-computed tomography (µCT), surface features were evaluated using scanning electron microscopy (SEM), and elemental analysis was performed using energy dispersive x-ray spectroscopy (EDS) . For specimens treated only with self-assembling peptide P11-4, the caries lesion area (mm2) values were 38.19 and 21.62, and the caries lesion volume (mm3) values were 6.27 and 2.99, respectively for pre- and post-treatment. In combination usage of self-assembling peptide P11-4 and laser, the caries lesion area (mm2) values were 38.39 and 16.91, and the caries lesion volume (mm3) values were 11.15 and 3.64, respectively for pre- and post-treatment. In the application of the P11-4 alone and in combination with laser, there was a statistically significant decrease in DiagnoDent values, an increase in enamel volume(mm3),enamel area(mm2) and mineral density(g/cm3) values and a decrease in caries lesion volume(mm3) and area(mm2) obtained by µCT, and an increase in %Ca and %F values obtained by SEM/EDS analysis (p < 0.05). It was discovered that the samples treated with P11-4 had a considerably higher rise in the Ca/P ratio than the samples treated with FV (p < 0.05). The calcium content increased significantly more when P11-4 application was combined with laser irradiation (p < 0.05). The combined use of self-assembling peptide P11-4 and laser accelerated the remineralization process and increased the remineralization capacity. FV and P11-4, alone or in combination with laser, can be successfully used as remineralization agents in initial enamel caries.

Neutron-based analytical techniques for the elemental composition analysis of electronic waste samples: advantages and challenges

AbstractRecycling electronic waste (WEEE) is a fundamental aspect of the circular economy. To develop technology and assess its economic aspects, the composition characterization of the waste items is crucial. Neutron-based analytical techniques, such as the INAA, in-beam NAA, and PGAA, are applicable to measure the elemental composition of WEEE. These techniques are bulk representative and offer simultaneous determination of the relevant elements without sample dissolution. This study explores the suitability of neutron-based elemental analysis methods for measuring common WEEE items, e.g., printed circuit boards and integrated circuits. Matrix effects mostly related to the thermal neutron self-shielding, were identified and successfully corrected, ensuring accurate mass fraction measurements.

Exploring dual-channel ion detection and theoretical insights: Chromone-based colorimetric receptor for Cu2+and its Zn(II)-complex as ultrasensitive fluorescent probe for Ag+ and Fe3+

Present article delineates the design and synthesis of a chromone-appended Schiff base (1) and its complexes with Zn(II) (2) and Cu(II) (3), which have been characterized by various spectro-analytical techniques i.e., elemental analysis, FTIR, 1H & 13C NMR, ESI-MS, UV−vis and fluorescence. Structures of 1 and 3 have also been elucidated using single crystal X-ray diffraction analysis. Compounds 2 showed significant effect in vitro cytotoxicity as compared to 1 Against MDA−MB-231 cell line. Interestingly, 1 serves as a chromogenic sensor for Cu2+ with exceptional selectivity whereas, 2 serves as an ultrasensitive fluorescent probe for Ag+ and Fe3+ in mixed aqueous−ethanol. The presence of Ag+ causes ratiometric change in the fluorescence spectral feature of 2 whereas Fe3+ induces ‘turn-off’ fluorescence in 2. Probe−analyte binding stoichiometry suggested by Job's plot analysis, ESI−MS and DFT studies, has been found to be 1:1 for 1 with Cu2+ and 2 with Ag+ whereas, 1:2 between 2 and Fe3+. Based on diverse analyses and binding constants, it is observed that 2 offers higher selectivity toward Ag+ over Fe3+. Limit of detection (LoD) of 1 for Cu2+ and 2 for Ag+ and Fe3+ have been found to be 2.33 nM, 22.4 µM and 2.05 µM, respectively. Complexes 2+Ag+ and 2+Fe3+ characterized by ESI−MS whereas DFT studies have been carried out to investigate the deeper bonding insights and provide support in our experimental investigations. Further, detection of Ag+ and Fe3+ has been practically accomplished in real water samples using probe 2.

Preparation of SiO2-IR3535 mosquito repellent nanocapsules and its performance study

The exploration of functional textiles signifies an inexorable path in the future advancement of the textile industry. In this study, sol-gel method was employed to encapsulate IR3535, a mosquito repellent substance, into silica nanocapsules, resulting in the production of silica-ethyl butylacetylaminopropionate (SiO2-IR3535) mosquito repellent nanocapsules with effective mosquito repellency. By manipulating factors such as surfactant dosage, ammonia dosage, wall-to-core ratio, alcohol-to-water ratio, rotational speed, reaction time, and reaction temperature, during the preparation process, the particle size was cpntrolled and optimal conditions for subsequent spining processes was obtained. The prepared SiO2-IR3535 mosquito-repellent nanocapsules exhibited uniform appearance and morphology with consistent size distribution (average particle size: 342 nm). In addition, these nanocapsules exhibited enhanced heat resistance and an oil loading rate of about 13 % as confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), infrared spectroscopy (FTIR), Raman spectroscopic simultaneous thermal analysis (STA), and elemental analyses, and kinetic modeling was performed to fit the release profiles of these capsules. Additionally, SiO2-IR3535 nanocapsules were added into polypropylene fiber by melt spinning method, the prepared polypropylene fiber has been uniformly dispersed both internally and externally within the fiber, thereby it can provide a sustained mosquito-repellent effect to the polypropylene fiber with SiO2-IR3535 nanocapsules.

Synthesis and antioxidant activity of gallic acid based fluorescent benzothiazole analogue: Photophysical, electrochemical, conceptual DFT, QTAIM and docking investigations

The present investigation reports on the synthesis of a novel 3,4,5-trihydroxy-N-(6‑methoxy benzo[d]thiazol-2-yl)benzamide (TMTB) molecule and employs elemental analysis, 1H NMR, 13C NMR, and mass spectrum methods to determine the structure of the desired product. The experimental and theoretical absorption and emission spectra of the molecules are used to study the photophysical properties of the TMTB molecule. We investigate the in vitro antioxidant activity of TMTB using DPPH and superoxide radical scavenging assays, as well as molecular docking experiments with the target NAD(P)H oxidase (PDB ID: 2CDU) protein. To ascertain the energies of the LUMO and HOMO levels, NLO behaviour, intermolecular charge transport facilitated by global chemical reactivity descriptors, molecular electrostatic potentials (MEP), and hyperpolarizability analyses, an investigation was carried out on their conceptual DFT and QTAIM analyses operating under B3LYP/6–31 G. The simulated DFT calculation shows that TMTB is highly polarizable in both the gas and solvent phases, with HOMO-LUMO energy gaps of 4.18 and 4.24 eV, respectively. Total first and second hyperpolarizability values for TMTB in the gas phase were determined to be 155.09 × 10–30 and 3611.59 × 10–36 esu, respectively, whereas in the DMSO phase the values were 556.15 × 10–30 and 6223.79 × 10–36 esu. Computational studies results corroborate the experimental findings. Based on the photophysical and computational findings, the newly reported TMTB molecule was determined to be a promising candidate for additional optimization and use in optoelectronic devices.

Exploring the use of fast electron backscattering for the determination of the C/O ratios: possible applications to graphene oxide and reduced graphene oxide

GO and rGO are carbon nanostructures with a wide range of applications. The carbon/oxygen ratio (C/O) is a basic parameter that determines many of its essential properties. The large-scale production of these materials requires the use of fast and representative methods to determine the C/O ratio. In the present work, the feasibility of using fast electron backscattering to determine this relationship was explored. The method is rapid and does not require previous sample treatment, its accuracy is approximately 11%–15% for C/O ∼ 10–35 and its precision is around 0.4%. It was estimated that the backscattered electrons being detected came from a sample mass of 0.04–0.4 g, depending on the synthesis method used. The accuracy of the backscatter method is approximately equal to that of EDX and XPS, but it surpasses them in precision and representativeness. Backscattering equipments are more economical when compared to the above-mentioned techniques; however, it can be affected by the presence of impurities. Therefore, we consider it an appropriate method for the large-scale control of samples of GO and rGO produced by a given technology and calibrated with a rigorous elemental analysis.

Coupling aquathermolysis of water-heavy oil-methanol catalyzed by o-phenanthroline-Cu(II) complex at low temperature

In this study, a Cu(II) coordinated complex was synthesized using o-phenanthroline and copper chloride. The synthesized complex, serving as a aquathermolysis catalyst, significantly reduces heavy oil viscosity at lower temperatures. Studies indicate that at a reaction temperature of 200 °C, with a catalyst concentration of 0.1% and a reaction duration of 6 h, heavy oil viscosity significantly reduces. Heavy oil viscosity dropped from 392,000 mPa∙s to 63,000 mPa∙s, achieving an 83.93% reduction rate. This catalyst maintains superior catalytic performance at lower temperatures compared to other catalyst types. Using methanol as a hydrogen donor further enhances the catalyst’s effect, increasing the heavy oil viscosity reduction rate from 83.93% to 88.63%. Thermogravimetric, four-component, and elemental analyses reveal that aquathermolysis of heavy oil primarily occurs in its heavier components. Following the aquathermolysis reaction, there is an increase in light components and a decrease in impurity atoms in heavy oil, resulting in improved crude oil quality.

Flexible Coordination of SacNac Ligands in Iridium Complexes and their Application to Catalytic Hydroboration

Herein, we report the synthesis and characterization of a small family of Ir(I) and Ir(III) complexes supported by β‐thioketoiminates (SacNac) ligands. All complexes were fully characterized by IR, 1D and 2D NMR, and Elemental Analysis (e.a.) experiments. X‐ray diffraction studies were carried out to corroborate the structure of compounds [Ir(cod)(SacNac)] (1) (cod = 1,5‐cyclooctadiene), [Ir(dmb)(SacNac)] (2) (dmb = 2,3‐dimethyl‐1,3‐butadiene) and [IrCp*(SacNac‐H)(Cl)2] (8) (Cp* = pentamethyl‐cyclopentadienyl). Complexes 1 and 2 are Ir(I) species and have square‐planar geometry in solid state, with bond angles and distances that suggest semi‐aromaticity in the six‐membered ring. To the best of our knowledge, we report the first mono‐coordination mode of a SacNac ligand via sulfur atom in complex 8. Also, we report the first application of iridium‐SacNac complexes as catalytic precursors in hydroboration reactions, where Ir(III) species give the best results.

Urea-lactic acid as efficient lignin solvent and its practical utility in sustainable electrospinning

The development of lignin-based materials presents a promising avenue for advancing green chemistry and mitigating environmental impact. However, the key challenge lies in the processability of lignin, which significantly affects its practical applications. Addressing the issues related to lignin's complex structure, variability, and reactivity is crucial for optimizing its incorporation into high-performance materials. Therefore, in this study we explore the efficacy of a urea-lactic acid-based deep eutectic solvent (ULA) for the dissolution of kraft lignin, aiming to enhance its practical utility in sustainable electrospinning processes, for the first time. Results of elemental analysis, IR and 2D NMR spectroscopy, provide crucial insights into the structural properties of the regenerated material post-DES treatment. The findings confirm a high lignin recovery rate, reaching up to 96.6 % for samples dissolved at 100°C. Additionally, 2D NMR analysis indicates that the process leads to partial esterification of lignin with lactate ions. The ability of the studied DES to effectively solubilize lignin underscores its potential as an efficient lignin solvent and facilitates the fabrication of lignin-based nanofibers via electrospinning. The incorporation of this DES in electrospinning processes promises significant advancements in the development of sustainable, lignin-derived materials and offers a green alternative for production of high-performance nanofibers. Preliminary results of electrochemical impedance spectroscopy and galvanostatic charge/discharge measurements confirm that the EDLC with prepared hydrogel electrolyte demonstrates attractive electrochemical properties (specific capacitance, CSP = 95 F g–1; series resistance RS = 2.2 Ω; charge transfer resistance, RCT = 1.6 Ω), which are comparable with the reference cell based on a commercial glass fibre separator. Hence, the DES-assisted-electrospinned lignin membrane can be viewed as a potential gel electrolyte matrix for practical use in construction of sustainable energy storage devices.

Correlative morphological, elemental and chemical phase analyses at the micrometric scale of powdered materials: Application to nuclear forensics

To characterize a mixture of powders using several analytical techniques, it is necessary that successive analyses be carried out on well-identified and localized particles, so that each characterization corresponds to a given powder. In this publication, powdered nuclear materials are characterized at the morphological and elemental levels with a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS) and at the chemical level with a micro-Raman spectrometer (MRS). However, to avoid a time-consuming and insufficiently accurate microparticle relocation process between SEM/EDS and MRS, micro-Raman analyses are carried out inside the SEM using a coupling device. In this way, all three pieces of information are obtained for exactly the same micrometric spot, without moving the sample or relocating the microparticles analyzed. The information can therefore be combined to characterize each component of the mixture. In this article, we describe in detail the methodology we have developed and optimized for morphological, elemental and chemical analysis of microparticles using a combined SEM/EDS and SRM. This methodology has been applied to powdered nuclear materials in two international nuclear forensics exercises. In the first exercise, named CMX-6, the combined use of the two instruments identified the presence of PuO2 microparticles and several uranium compounds (UO2, U3O8, UO2F2) in both materials. In the second exercise, called CMX-7, the methodology developed enabled us to distinguish two chemical phases of uranium, a uranyl oxy-hydroxide and a uranyl nitrate, each characterized by specific morphologies and the detection or non-detection of a minor elemental constituent (calcium).

Microstructural and elemental analyses of slags excavated from the Gushishan iron‐smelting site, Sichuan Province, China

AbstractThe Shu Commandery was an important iron production center in southwest China during the Han Dynasty (202 BC‐AD 220). In 2007, archaeologists excavated a Han Dynasty smelting furnace (L1) at the Gushishan site and collected large amounts of smelting remains including slags, furnace bricks, and ores. Scientific analysis of the excavated slags was carried out to ascertain that the Gushishan site was a pig iron smelting site. No flux was used at the Gushishan site, and the site is dated no later than the Eastern Han period. No remains related to iron casting of the Han Dynasty was found at or near the iron smelting sites in southwest China, which indicates a separation between iron smelting and iron casting as characteristics of the industrial layout in this region.

A case of early childhood caries from a Medieval site in Southern Portugal: a multidisciplinary approach.

Dental caries is the most prevalent chronic infectious disease during childhood both in historical and contemporary times, but research focused on the oral health of non-adults from the past is still scant. As such, this study proposes a multidisciplinary approach to the differential diagnosis of severe dental lesions in a medieval non-adult skeleton. The skeleton of a three-year-old child recovered in the medieval necropolis of Cacela Velha (Portugal) was studied through macroscopic, radiological, elemental and stable isotope analyses. This individual exhibited enamel destruction and dentine exposure in both the maxillary and mandibular teeth, with the latter also showing changes in coloration. Elemental analysis showed that his skull presented lower values of Si, Cl, and Ca and higher of Cu compared to the control, while the concentration of P and S were significantly lower in the teeth. Early childhood caries is the most probable diagnosis for the dental lesions observed, apparently stemming from a reticulate of factors that include potential malnutrition, and the consumption of sugars in complementary feeding - even though historical sources point to the scarcity of sugar in Portugal during most of the Middle Ages.