Energy Dispersive X-ray Elemental Analysis Research Articles

Wet-chemical preparation and physicochemical characterization of nanostructured Zn-Bi2O3/CeO2 composite: A visible-light-driven catalyst for the annihilation of pharmaceutical pollutant

A modified co-precipitation technique assisted with cetyltrimethylammonium bromide (CTAB) surfactant was used to synthesize a nanostructured and zinc-doped mixed metal oxide (Zn-Bi2O3/CeO2) composite. Using X-ray diffraction (XRD), the synthesized nanocomposite was studied in terms of its crystal structure, grain size, percentage crystallinity, and percentage porosity. Energy dispersive X-ray elemental analysis (EDX) was used to ascertain the chemical composition, SEM to confirm the creation of nanostructure material, and Fourier transform infrared spectroscopy (FTIR) to extract the existing functional groups. Investigation of light harvesting properties (UV/Vis) and thermogravimetric analysis (TGA) reveals that the doped composite exhibits a band gap driven by visible light and remarkable thermal stability at high temperatures. The pH value at which a material's net charge is zero, known as pHpzc, is 7.93 for the doped mixed metal oxide composite. The Zn-Bi2O3/CeO2 nanocomposite effectively eliminates 98.4 percent of the quinolone antibiotic (levofloxacin) via a mechanism that integrates sorption and photocatalytic degradation induced by visible light. To determine the optimal circumstances for the efficient operation of a photocatalyst, we experimented with different time intervals, beginning drug concentrations, catalyst dosages, operating temperatures, and pH levels. Reusability tests and post-activity FTIR analysis were used to investigate the long-term usability and structural stability of the newly developed doped composite photocatalyst. The scavenging tests revealed a potential photocatalytic mechanism to explain the annihilation of the levofloxacin drug on the synthesized catalyst. The physicochemical and photocatalytic evaluations recommend that the assembled integrated material has excellent potential for mineralizing medicinal products in pharmaceutical wastes.

Comparative study on mechanical properties and biomineralization of hooks in the diaspores of three epizoochorous plant species

Most of the plants using epizoochory show adaptations to this diaspore dispersal strategy by having the diaspores covered by barbs, hooks, spines or viscid outgrowths, which allow diaspores to easily attach to an animal surface. Many previous studies have been mainly focused on the dispersal distances and efficiency, or effectiveness of diverse attachment structures depending on their size, anatomy, and morphology. However, the knowledge about the mechanical properties of these structures remains rather poor. In this study, we use a combination of scanning electron microscopy, energy dispersive X-ray element analysis and nanoindentation, to examine the microstructure, biomineralization and mechanical properties of single hooks in Arctium minus, Cynoglossum officinale and Galium aparine. Both the biomineralization and mechanical properties of the hooks strongly differ in examined plant species; mechanical properties depend on the biomineralization pattern, such as the accumulation of silicon and calcium. Elastic modulus and hardness decrease in the series C. officinaleG. aparineA. minus. Anisotropic mechanical properties are found between the radial and longitudinal directions in each single hook. By characterizing the mechanical properties and biomineralization of plant hooks, this paper contributes to the understanding of attachment biomechanics related to seed dispersal. Statement of significanceThe dispersal of seeds is essential for plant survival. Many of the plants that use the outside surface of animals to transport the seeds show adaptations to this dispersal strategy by having the seeds covered with hooks. Although these hooks have various sizes, morphologies and anatomical structures, all of them provide mechanical interlocking to animal surfaces. To reduce the risk of interlocking failure, the hooks are usually reinforced by mineralization. However, the relationship between mineralization, mechanical properties and specialized function of plant hooks has been largely overlooked. Here we perform a characterization study on the hooks of three plant species. Our results deepen the current understanding of the mineralization-material-function relationship in specialized hooks of plant seeds.

Exploring the impact of wire core diameter on microstructure and joint properties in ultrasonic wire harness welding

The present study investigates ultrasonic metal welding to manufacture 10 mm2 copper (Cu) wire joints with different core diameters. The primary purpose of this study is to explore the influence of wire core diameter on the performance of ultrasonic welded joints. Wire core diameter is positively correlated with the peeling resistance of the joint. Superior mechanical properties of the joint are achieved with an increased diameter of the wire core. The peeling strength of the welded joint of two wires with a wire core diameter of 0.25 mm reaches 306.8 N. Examining the welding temperature and assessing the joint's porosity reveals a significant impact of temperature on porosity. However, relying solely on porosity as a criterion for judging the overall forming quality of joints may be insufficient. Scanning electron microscope and energy-dispersive X-ray elemental analysis revealed that certain wires underwent plastic deformation at elevated temperatures without attaining atomic bonding. Additionally, the welded joint exhibits a compact structure externally and a more relaxed structure internally. The upper side of the joint in contact with the briquette and the lower side in contact with the welding head exhibit minimal gaps, while numerous gaps are evident in the middle of the joint. Furthermore, upon examining the fracture morphology, two distinct failure modes are identified at the joint surface of the conductor. The first involves the fracture of the wire core with a completely separated joint surface, resulting in poor mechanical properties of the joint. The second mode entails the ductile fracture of the wire core at the joint surface, indicating good mechanical properties of the joint.

One-pot synthesis of quinazolinone heterocyclic compounds using functionalized SBA-15 with natural material ellagic acid as a novel nanocatalyst

The nanoporous compound SBA-15 was functionalized using (3-aminopropyl)trimethoxysilane (APTES). Then the obtained product was modified with ellagic acid (ELA), a bioactive polyphenolic compound. The structure of the prepared nanoporous composition SBA-15@ELA was extensively characterized and confirmed by various techniques, such as Fourier-transform infrared (FT-IR) spectroscopy, Energy dispersive X-ray (EDX) elemental analysis, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and N2 adsorption–desorption isotherms (BET). The novel, recoverable, heterogenous SBA-15@ELA nanoporous compound was used to investigate its catalytic effect in the synthesis of 4-oxo-quinazoline derivatives (19 examples) with high yields (78–96%), as an important class of nitrogen-containing heterocyclic compounds. The use of an inexpensive mesoporous catalyst with a high surface area, along with easy recovery by simple filtration are among the advantages of this catalysis research work. The catalyst has been used in at least 6 consecutive runs without a significant loss of its activity.

Thiourea modulated supercapacitive behavior of reduced graphene oxide

In this report, we investigated the role of the concentration of nitrogen and sulfur containing thiourea in modulating the electrochemical properties of reduced Graphene Oxide (rGO) by controlling the percentage of heteroatoms on the rGO surface. The synthesis route involved the preparation of Graphene Oxide (GO) using an improved method of synthesis in an economical way by reducing the volume of concentrated acids used. Furthermore, GO is reduced by using different mass proportions of thiourea via a simple reflux method. Characterization of the rGO samples by Fourier Transform Infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDAX) and elemental analysis through CHNS analyzer exhibited successful doping and impact of nitrogen and sulfur atoms on the graphene framework. The comparative electrochemical performance from Cyclic Voltammograms (CV), Galvanostatic Charge Discharge (GCD) profiles and Electrochemical Impedance Spectroscopy (EIS) measurements on the various rGO samples revealed the superiority of 1:8rGO having 15.190 wt% of nitrogen and 26.849 wt% of sulfur and S/N ratio of 1.768, in delivering highest specific capacitance of 465.21 F·g−1 at 1 mV·s−1 scan rate with a remarkable cyclic stability exhibiting a capacitive retention of 119 % and offering lowest charge transfer resistance and diffusion resistance. The study also demonstrated detrimental effect of excess thiourea on electrochemical properties of rGO. This work suggests an effective and simple approach for optimizing the nitrogen and sulfur content in rGO to enhance its electronic properties using thiourea.

A comprehensive characterization of indoor ambient microplastics in households during the COVID-19 pandemic

AbstractAirborne microplastics (MPs) can be easily inhaled by humans, impacting their health as they spend more than 80% of their time indoors, especially during the pandemic. Only a few research studies have examined indoor MPs in the micrometer size range using active sampling, and studies have mainly concentrated on MPs that are millimeters in size. This study investigated the composition of indoor airborne MPs by active sampling in seven houses in the city center of northwestern Turkey (Eskişehir) during the COVID-19 pandemic. The visual identification showed the presence of different colored MPs, white, red, orange, green, and yellow, with different shapes (fibers, fragments, films, lines, foam, and pellets). The size of the identified MPs was between 2.5 and 327.36 μm. The polymeric composition analysis showed the presence of 123 MPs in all the samples with 22 different polymeric compositions. Residents in these houses are exposed to airborne MPs, with inhalation estimates ranging from 12.03 to 18.51 MPs/m3. However, it was also estimated that humans inhale 156–240 MPs daily in these houses. The dominant MPs were polyamide 6, polyvinyl chloride, polypropylene, ethylene propylene, polystyrene, and high-density polyethylene. Scanning electron microscopy energy dispersive x-ray elemental analysis revealed the presence of common structural elements, additives, or vectors that are added or adsorbed to MPs like carbon, oxygen, fluorine, magnesium, silicon, chlorine, nitrogen, and aluminum. These indoor environments are prone to MP pollution. Still, the MP level varies due to different characteristics of indoor environments, like activities and the number of occupants/people in the space, etc. The smaller MPs in all the samples highlight the necessity for standardized techniques of MP collection.

Exploration of a wide bandgap semiconducting supramolecular Mg(II)-metallohydrogel derived from an aliphatic amine: a robust resistive switching framework for brain-inspired computing

A rapid metallohydrogelation strategy has been developed of magnesium(II)-ion using trimethylamine as a low molecular weight gelator in water medium at room temperature. The mechanical property of the synthesized metallohydrogel material is established through the rheological analysis. The nano-rose like morphological patterns of Mg(II)-metallohydrogel are characterized through field emission scanning electron microscopic study. The energy dispersive X-ray elemental mapping analysis confirms the primary gel forming elements of Mg(II)-metallohydrogel. The possible metallohydrogel formation strategy has been analyzed through FT-IR spectroscopic study. In this work, magnesium(II) metallohydrogel (Mg@TMA) based metal–semiconductor-metal structures have been developed and charge transport behaviour is studied. Here, it is confirmed that the magnesium(II) metallohydrogel (Mg@TMA) based resistive random access memory (RRAM) device is showing bipolar resistive switching behaviour at room temperature. We have also explored the mechanism of resistive switching behaviour using the formation (rupture) of conductive filaments between the metal electrodes. This RRAM devices exhibit excellent switching endurance over 10,000 switching cycles with a large ON/OFF ratio (~ 100). The easy fabrication techniques, robust resistive switching behaviour and stability of the present system makes these structures preferred candidate for applications in non-volatile memory design, neuromorphic computing, flexible electronics and optoelectronics etc.

Jute leaves ash@Fe3O4 as efficient nanocatalyst for sustainable biodiesel production: Characterization, optimization and kinetic investigation

A magnetically separable heterogeneous basic jute leaves ash@Fe3O4 nanocatalyst was utilized for biodiesel synthesis from jatropha and soybean oil. The magnetic catalyst was synthesized via calcination process followed by co-precipitation method. The XRD(X-ray diffraction) and FTIR(Fourier transform infrared) analysis confirmed the existence of magnetic Fe3O4, various metal oxides and carbonates in the catalyst. The jute leaves ash@Fe3O4 nanocatalyst was found in quasi spherical and core/shell structured in nature with average particle size of 15.66 nm. The XPS (X-Ray Photoelectron Spectrometer) and EDX (Energy Dispersive X-ray) elemental analysis showed the high content of calcium (21.5%) and potassium (4.8%) which makes the catalyst extremely basic in nature. The calculated basicity and surface area of the catalyst was 0.609 mmol g−1 and 85.5 m2 g−1 respectively and the reaction exhibits activation energy of 34.75 kJ mol−1. The VSM(Vibrating sample magnetometer) analysis recorded the magnetic saturation of uncalcined ash and calcined ash loaded magnetic catalyst as 17.32 and 12.56 emu g−1. The synthesized basic nanocatalyst furnishes maximum 98.1 ± 1.27% biodiesel yield after 60 ± 2 min with the catalyst load and methanol to oil ratio of 6 wt% and 9:1 at 60 °C. The magnetic catalyst was effectively employed in three consecutive cycles with promising catalyst stability and reactivity toward transesterification.

Uniformly Dispersed Cobalt Catalyst on the Coffee Waste-Derived Carbon Support for Hydrogen Evolution Reaction

The research interests in transition metal catalysts on carbon support have increased last decade for expensive noble metal catalyst replacement. Because those catalysts have a large surface area, good chemical stability, and are cheap and earth-abundant. Mainly structured with Co-N-C catalysts such as Cobalt (Co) nanoparticle embedded N-doped carbon, Co single-atom catalyst on carbon, etc., are highly efficient for hydrogen evolution reaction (HER) in acidic and alkaline electrolytes.Here, we report the uniformly dispersed cobalt catalysts (Co-SCC-N) on nitrogen (N)-doped spent coffee grounds (SCG) derived carbon support, which was further utilized as HER electrocatalyst. In the first step, SCG-derived carbon is synthesized by simple pyrolysis with ZnCl2. Then, the cobalt catalyst is prepared by adsorption of the complex Co ion with 1,10-phenanthroline on the SCG-derived carbon support, followed by pyrolysis at 800°C under a nitrogen atmosphere. Uniform and high dispersions of cobalt on the carbon substrate have been confirmed by scanning transmission electron microscopy (STEM) and energy dispersive X-ray (EDX) elemental mapping analysis. X-ray photoelectron spectroscopy (XPS) determined that the catalyst contained Co2+ ions and had nitrogen-doped. Also, X-ray diffraction (XRD) and Raman spectroscopy revealed carbon materials disorders, crystallinity, and no metal-related peaks that validated no metal clusters on the carbon. Electrochemical tests were examined by linear sweep voltammetry, Tafel, electrochemical impedance spectroscopy, and chronopotentiometry (CP) in alkaline and acidic electrolytes. Co-SCC-N exhibited excellent HER performance in an alkaline medium, which needed 0.246 V to reach 10 mA cm-2. And the CP test confirmed better stability at 10 mA cm-2 for 12 hours. The result recommends a simple synthesis method for uniformly dispersed metal catalysts on biomass-derived carbon support by a simple pyrolysis technique.

Crystal Structure of Bismuth-Containing Samarium Iron–Aluminium Borates Sm1−xBixFe3−yAly(BO3)4 (x = 0.05–0.07, y = 0–0.28) in the Temperature Range of 25–500 K

Structural features of new mixed bismuth-containing samarium iron–aluminium borate single crystals Sm1−xBixFe3−yAly(BO3)4 (x = 0.05–0.07, y = 0–0.28) were studied using X-ray diffraction analysis based on aluminium content and temperature in the range 25–500 K. The crystals were grown using the solution-in-melt technique with Bi2Mo3O12 in a flux. The composition of the single crystals was analyzed using energy-dispersive X-ray fluorescence and energy-dispersive X-ray elemental analysis. Temperature dependencies of Sm1−xBixFe3−yAly(BO3)4 unit-cell parameters were studied. Negative thermal expansion was identified below 100 K and represented by characteristic surfaces of the thermal expansion tensor. (Sm,Bi)–O, (Sm,Bi)–(Fe,Al), (Fe,Al)–(Fe,Al), and (Fe,Al)–O interatomic distances decreased with the addition of aluminium atoms. An increase in the (Fe,Al)–(Fe,Al) intrachain bond length at low temperatures in the magnetically ordered state weakened this bond, whereas a decrease in the (Fe,Al)–(Fe,Al) interchain distance strengthened super-exchange paths between different chains. It was found that the addition of aluminium atoms influenced interatomic distances in Sm1−xBixFe3−yAly(BO3)4 much more than lowering the temperature from 293 K to 25 K. The effect of aluminium doping on magnetoelectric properties and structural symmetry of rare-earth iron borates is also discussed.

A feasibility study on the green synthesis of iron oxide nanoparticles using Chlorella vulgaris extract for photocatalytic degradation of crystal violet

Iron oxide nanoparticles have recently been proposed as an efficient and environmentally friendly material for wastewater treatment. In comparison to chemical and physical approaches, green nanoparticles synthesis method that employs microalgae or plant extract is regarded as more cost-effective and environmentally friendly. In this study, iron oxide nanoparticles were synthesised using Chlorella vulgaris extract, and their feasibility in removing crystal violet dye from wastewater via photocatalytic degradation was investigated. Iron oxide nanoparticles was synthesized by adding C. vulgaris extract to 0.1 M iron (III) chloride solution. The X-ray diffraction (XRD) peaks revealed that the iron oxide nanoparticles were crystalline in nature. The nanoparticles were also analysed using Field Emission Scanning Electron Microscope (FESEM), revealing a sphere with cylindrical shape of about 109 nm in size, with the Energy Dispersive X-ray (EDX) elemental analysis showing the highest proportion of O followed by Fe. The ability of iron oxide nanoparticles to remove crystal violet dye in the dark and in the presence of ultraviolet (UV) light was investigated. The percentage removal was consistently higher under the presence of UV lamp at all durations tested (30 – 90 minutes), indicating the feasibility of iron oxide nanoparticles to photodegrade crystal violet dye.

Biochemical and histopathological studies of sulfonylurea derivative as a new chemotherapeutic agent against liver cancer in free- and nano-coated forms

The most frequent type of primary liver cancer is hepatocellular carcinoma (HCC), accounting for approximately 90% of primary liver cancers and a third leading cause of cancer deaths. In the current study, the synthesized compound 3 was re-formulated using tetraethyl orthosilicate (TEOS) with weight ratio (1:1) via sol-gel technique. The prepared material has been examined using Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray elemental analysis (EDX), and scanning and transmission electron microscopes (SEM and TEM). Herein, we investigate the mode of action of 3 as potent anti-liver cancer in vivo as normal and nano-forms. Rats were given a single dosage of 50 mg/kg b.wt. of HCC through an intraperitoneal injection (ip). A single dosage of CCl4 (2 ml/kg IP) was also given to rats 2 weeks later. Several liver, tumor and oxidative stress biomarkers were detected including liver enzymes; alanine and aspartate aminotransferases (ALT and AST), alkaline phosphatse (ALP), gamma glutamyl transferase (GGT), glutathione (GSH), lipid peroxide (MDA), catalase (CAT), superoxide dismutase (SOD), total antioxidant capacity (TAC), α-fetoprotein and α-L-Fucosidase. Hepatic pathological pictures were also performed for the documentation of the presence of HCC and supported the biochemical results. Moreover, the DNA damage in liver tissues of male rats using comet assay was studied. The results showed that the HePG2 (− ve) group of rats exhibited a significant reduction (P < 0.05) in DNA damage values (9.30 ± 0.89) relative to other treatment groups. Nevertheless, the DNA damage values in the HePG2 (+ ve) and 5-flurouracil groups were significantly higher (P < 0.01) compared to the HePG2 (− ve) group. Additionally, HePG2 (coated 3) and HePG2 (3) groups exhibited significant decrease in the DNA damage compared to those in HePG2 (+ ve) group.

Fruit peel-based mesoporous activated carbon via microwave assisted K2CO3 activation: Box Behnken design and desirability function for methylene blue dye adsorption

A low-cost fruit waste namely watermelon peel (WMP) was utilized as a promising precursor for the preparation of mesoporous activated carbon (WMP-AC) via microwave assisted-K2CO3 activation. The WMP-AC was applied as an adsorbent for methylene blue dye (MB) removal. Several types of characterizations, such as specific surface area (BET), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX), Elemental Analysis (CHNS/O), and Fourier Transform Infrared Spectroscopy (FTIR) were used to identify the physicochemical properties of WMP-AC. Furthermore, Box-Behnken design (BBD) was applied to optimize the influence of the adsorption operational variables (contact time, adsorbent dose, working temperature, and solution pH) on MB dye adsorption. Thus, based on significant interactions, the optimum BBD output shows the best removal of 50 mg·L−1 MB (92%) was recorded at an adsorbent dose of 0.056 g, contact time of 4.4 min, working temperature of 39 °C, and solution pH 8.4. The Langmuir uptake capacity of WMP-AC was found to be 312.8 mg·g−1, with the best fitness to the pseudo-second-order kinetics model and an endothermic adsorption process. The adsorption mechanisms of MB by WMP-AC can be assigned to the hydrogen bonding, electrostatic attraction, and π–π stacking. The findings of this study indicate that WMP is a promising precursor for producing porous activated carbon for MB dye removal.

Facile extraction and characterization of calcium hydroxide from paper mill waste sludge of Bangladesh.

Herein, paper mill waste sludge (PMS) from two different sources has been investigated to extract calcium hydroxide, Ca(OH)2 by a facile and inexpensive extraction process. PMS samples, collected from local paper mill plants of Bangladesh, were the main precursors wherein HCl and NaOH were used for chemical treatment. The as-synthesized products were analysed by a variety of characterization tools including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) elemental analyses. Our studies confirm that the extracted product contains Ca(OH)2 as a major content, albeit it also includes CaCO3 phase owing to the inescapable carbonation process from the surrounding environment. The particle size of the synthesized products is in the range of 450–500 nm estimated from SEM micrographs. The crystallite domain size of the same estimated from XRD analyses and was found to be approximately 47 and 31 nm respectively for product-A and product-B considering major (101) Bragg peak of Ca(OH)2. The yield percentage of the isolated products is about 65% for samples collected from both sources.

Perovskite nanocomposite of defective yolk-shell BaHo2Co3O8-x for electrochemical sensing of ractopamine in pork meat sample

Since ractopamine (RPA) can increase high growth rates in cattle and swine, illegal RPA usage has been widespread in many farming enterprises. Owing to the possible damage to public health, RPA detection has become a critical issue in recent decades. As a result, in order to maintain food safety, an analytical tool for rapid, precise, portable, and sensitive monitoring of RPA in animal tissues is required. In this study, the electrochemical sensor is developed for the first time by the defective yolk-shell of BaHo2Co3O8-x nanocomposites (perovskite types), which are synthesized using a hydrothermal followed by a calcination process. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FE-SEM), and high-resolution transmission electron microscope (HR-TEM) are used to investigate physicochemical characterizations. Moreover, the elements are confirmed by the energy dispersive X-ray spectrum (EDS) and elemental mapping analysis. Cyclic voltammetry (CV) and difference pulse voltammetry (DPV) are used to detect RPA by modified BaHo2Co3O8-x/SPCE. The electrochemical sensing ability of the modified BaHo2Co3O8-x/SPCE displays a broad linear response range (up to 200 μM) and an ultralow detection limit (0.029 μM). Furthermore, the BaHo2Co3O8-x/SPCE presents outstanding selectivity, good repeatability, long-term storage stability, and reproducibility for RPA detection in pork meat samples.

Chemical Composition and Flexural Strength Discrepancies Between Milled and Lithography-Based Additively Manufactured Zirconia.

To evaluate the chemical composition, flexural strength, and Weibull characteristics of milled and lithography-based additively manufactured (AM) zirconia. A virtual design of a bar (25×4×2mm) was completed using a software program. The standard tessellation language file was used to manufacture all the specimens: 3Y-TZP zirconia (Priti multidisc ZrO2 monochrome) milled (M group) and 3Y-TZP zirconia (LithaCon 3Y 210) lithography-based AM (CeraFab System S65 Medical) (AM group) bar specimens (n = 20). The chemical composition of the specimens was determined by using energy dispersive X-ray (EDAX) elemental analysis in a scanning electron microscope. Flexural strength was measured in all specimens using 3-point bend test according to ISO/CD 6872.2 with a universal testing machine (Instron Model 8501). Two-parameter Weibull distribution values were calculated. The Shapiro-Wilk test revealed that the data were normally distributed (p < 0.05). Flexural strength values were analyzed using independent Student's t-test (α = 0.05). There were no major chemical composition differences observed between M and AM groups. The AM specimens (1518.9 ± 253.9 MPa) exhibited a significantly higher flexural strength mean value compared to the milled (980.5 ± 130.3 MPa) specimens (DF = 13, T-value = -5.97, p < 0.001). The Weibull distribution presented the highest shape for M specimens (11.49) compared to those of AM specimens (6.95). There was no significant difference in the chemical composition of milled and AM zirconia material tested. AM zirconia tested exhibited significantly higher flexural strength compared with the milled zirconia evaluated.

Identification of factors affecting SEM/EDS analysis for discrimination and classification among common items of evidence using particle combination profiles

This article presents key factors affecting the analysis of particle profiles as used for discrimination and classification among items commonly collected at crime scenes. Identification of these factors is a necessary step to enable systematic improvement, optimization, and transition to practice.Prior research, employing reasonable initial choices of analytical and statistical parameters, has (1) demonstrated the presence of highly discriminating sets of very small particles (VSP) on the surfaces of items commonly collected at crime scenes, (2) developed statistically rigorous measurements of correspondence between VSP profiles, and (3) produced objective measures for the resulting probative value. In the present work the analytical and statistical parameters were examined more critically, identifying key factors affecting method performance.Experiments were conducted using scanning electron microscopy (SEM) with energy dispersive x-ray elemental analysis (EDS) to characterize the elemental composition of thousands of individual particles within each specimen. The experiments studied:Reproducibility of VSP analyses at given parametersEffects of the SEM/EDS parameters used for the detection of each particleEffects of SEM/EDS x-ray analysis parameters used for elemental analysis of each particleEffects of the number and choice of elements used in the elemental analysisEffects of particle size on the strength of correspondence between particle setsEffects of data filtration parameters on the strength of correspondence between particle setsThe experiments confirmed the presence of abundant, highly discriminating VSP on items commonly collected at crime scenes. The numbers of particles available for analysis was not a limiting factor: many more particles (usually greater than 50 times more) were present than were used for the analysis. A very high level of reproducibility was observed.Many of the parameters tested had no measurable effect on particle combination analysis performance and others had minor or interactive effects. Four factors were identified as having significant impact on the strength of correspondence between particle profiles, three factors were identified as having a significant impact on the numbers of particles detected and nine factors were identified as having a significant impact on analytical time and costs.The approach in its current state of development offers crime laboratories an additional capability suitable for high priority cases. The identification of key factors affecting performance of the VSP analytical protocol allows existing methods to be further developed and systematically improved to facilitate transition to routine practice.

Electrospun V2O5 nanofibers as high-capacity cathode materials for zinc-ion batteries

Vanadium pentoxide (V2O5) has attracted significant attention in recent years as a cathode material for aqueous zinc-ion batteries (AZIBs). Its unique layered structure allows for reversible intercalation of various multivalent ions, including Zn2+.This paper proposes a sol–gel electrospinning method for preparation of vanadium pentoxide nanofibers, followed by thermal treatment in air. The composition and structure of the obtained powders were verified by X-ray diffraction, energy-dispersive X-ray elemental analysis, and X-ray photoelectron spectroscopy, while the morphology of the samples was investigated by scanning electron microscopy. The electrochemical properties and performance of the electrode materials based on V2O5 nanofibers were studied using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy methods. V2O5 electrodes demonstrate high specific capacity (357 mA h g−1 at 0.05Ag−1) and good long-term cyclic stability.

Effect Of Calcium Silicate, Sodium Phosphate, and Fluoride on Dentinal Tubule Occlusion and Permeability in Comparison to Desensitizing Toothpaste: An In Vitro Study.

This study compared the ability of a calcium silicate-, sodium phosphate-, and fluoride-based (CSSPF) toothpaste (TP) in promoting dentinal tubule occlusion and reducing dentin permeability with that of other commercially available antisensitivity TPs. Seventy-eight dentin discs (1.0±0.1 mm thick) were prepared from the midcoronal area and were treated with 37% phosphoric acid for 2 minutes; then they were randomly divided into six groups according to treatments: No treatment [positive control (PC)], entirely covered with nail varnish [negative control (NC)], hydroxyapatite (HAP)-containing TP [Desensin Repair (DES)], NovaMin-based [Sensodyne Repair & Protect (SEN)], CSSPF-based TP [Regenerate Advanced (REG)], sodium monofluorophosphate, potassium citrate, zinc citrate TP [Signal Sensitive Expert (SIG)]. Dentin permeability was tested by the dye percolation method (DP%). Scanning electron microscope (SEM) micromorphological and energy dispersive X-ray elemental analysis (EDX) of the dentin surfaces were done following each treatment. Results were analyzed using one-way analysis of variance (ANOVA) followed by Tukey post hoc test at a 95% confidence level (α=0.05). All the tested groups showed higher DP% than NC and lower percolation than the PC (p<0.05). REG and SIG were statistically comparable, and showed significantly lower DP% (p<0.05) than SEN and DES. None of the TPs tested was able to obliterate the lumen of the dentinal tubules (DT) completely. REG exhibited the highest weight percentage of calcium deposition, followed by SEN. Compared to the tested desensitizing TPs, CSSPF-based TPs demonstrated equal or less dentin permeability and better DT occlusion.

Hydrothermal Synthesis and Improved CH₃OH-Sensing Performance of ZnO Nanorods With Adsorbed Au NPs

The high-density and well-aligned zinc oxide (ZnO) nanostructures with adsorbed gold (Au) nanoparticles (NPs) grown on indium-tin-oxide (ITO) glass substrates were used as a gas-sensing material. The Au NPs-adsorbed nanorod (NR) arrays were successfully grown on the substrates via the simple hydrothermal method at various Au NP sputter deposition times (0 and 30 s). The crystal characteristics, surface morphologies, and elemental distributions were studied by using the X-ray diffraction (XRD) spectrometry, the field-emission scanning electron microscopy (FE-SEM), and the high-resolution transmission electron microscopy (HR-TEM) with an energy dispersive X-ray (EDX) elemental mapping analysis, respectively. The NR structures were vertical to the substrate surface with hexagonal wurtzite structure and single-crystalline performance. All sensors were prepared in a self-made chamber, indicating that the response of the sample toward methanol (CH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> OH) vapor at different working temperatures was enhanced by Au adsorption. Additionally, the sensor showed a remarkably enhanced response (62.65%) to 1000 ppm CH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> OH at the optimal operating temperature of 150 °C. Simultaneously, the sensor evidently displayed stable and repeatable behavior, and selectivity toward the CH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> OH vapor with no substantial response to isopropyl alcohol, acetone, and ethanol vapors. The designed sensor in this investigation may detect harmful gas in the Internet of Thing applications.