Dispersive X-ray Elemental Analysis Research Articles

Functionalized biochar derived from novel Neolamarchia cadamba leaf extracts for the adsorption of Congo Red dye: kinetics, optimization, and reusability studies

ABSTRACT The present research emphasized on the removal of Congo Red (CR) dye from aqueous solutions using an adsorbent synthesized by utilizing the leaf extract of Neolamarchia cadamba as a bio-template. This facilitates the formation of zinc oxide nanoparticles which are then carbonized to enhance adsorption capabilities. This synthesized material is referred to as NC@ZnC, for coherent adsorption of CR dye. Various operating parameters were used for the adsorption of CR onto NC@ZnC. The maximum monolayer decontamination of CR dye was 303.03 mg/g when it was incubated for 90 min at a pH of 5. The specific surface area of amalgamated NC@ZnC was reported to be 6.509 m2/g using Bruaneur–Emmett–Teller analysis. Field-emission scanning electron microscopy was used to show the rough surface area, X-ray diffraction analysis was used to determine the crystalline structure of the adsorbent with a grain size of 20.062 nm. Elemental dispersive X-ray analysis was used to determine the elemental composition of NC@ZnC. Raman spectroscopy demonstrates a lysine group that, upon adsorption, interacts with oxygen to form a bond. NC@ZnC regresses pseudo-second-order kinetics and follows the Langmuir isotherm for the adsorption process. The sorption activity with respect to temperature appears to be displaying +ΔH° and +ΔS°, which suggests an endothermic and impulsive nature.

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.

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.

A novel oyster shell biocomposite for the efficient adsorptive removal of cadmium and lead from aqueous solution: Synthesis, process optimization, modelling and mechanism studies.

This study highlights the effectiveness of oyster shell biocomposite for the biosorption of Cd(II) and Pb(II) ions from an aqueous solution. The aim of this work was to modify a novel biocomposite derived from oyster shell for the adsorption of Cd(II) and Pb(II) ions from aqueous solution. The studied revealed the specific surface BET surface area was 9.1476 m2/g. The elemental dispersive x-ray analysis (EDS) indicated that C, O, Ag, Ca were the predominant elements on the surface of the biocomposite after which metals ions of Cd and Pb were noticed after adsorption. The Fourier transform Irradiation (FT-IR) revealed the presence of carboxyl and hydroxyl groups on the surface. The effect of process variables on the adsorption capacity of the modified biocomposite was examined using the central composite design (CCD) of the response surface methodology (RSM). The process variables which include pH, adsorbent dose, the initial concentration and temperature were the most effective parameters influencing the uptake capacity. The optimal process conditions of these parameters were found to be pH, 5.57, adsorbent dose, 2.53 g/L, initial concentration, 46.76 mg/L and temperature 28.48°C for the biosorption of Cd(II) and Pb(II) ions from aqueous solution at a desirability coefficient of 1. The analysis of variance (ANOVA) revealed a high coefficient of determination (R2 > 0.91) and low probability coefficients for the responses (P < 0.05) which indicated the validity and aptness of the model for the biosorption of the metal ions. Experimental isotherm data fitted better to the Langmuir model and the kinetic data fitted better to the pseudo-second-order model. Maximun Cd(II) and Pb(II) adsorption capacities of the oyster shell biocomposite were 97.54 and 78.99 mg/g respectively and was obtained at pH 5.56 and 28.48°C. This investigation has provided the possibility of the utilization of alternative biocomposite as a sustainable approach for the biosorption of heavy metal ions from the wastewater stream.

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.

Green Synthesis of Copper Oxide Nanoparticles Synthesized by Terminalia chebula Dried Fruit Extract: Characterization and Antibacterial Action.

Copper oxide nanoparticles (CuONPs) have emerged as potential antibacterial agents. In this study, we aimed to synthesize CuONPs using Terminalia chebula(T. chebula)dried fruit extract and evaluate their antibacterial activity against specific wound pathogens. Our primary objective was to comprehensively characterize driedT. chebula fruit (TCF)-CuONPs and assess their antibacterial efficacy. CuONPs were synthesized through a green synthesis approach employing T. chebula dried fruit extract. Structural and compositional characterization involved UV-visible spectroscopy, scanning electron microscopy (SEM), elemental dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM). The antibacterial activity of CuONPs was assessed against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli through various assays, including agar well diffusion, time-kill curve, protein leakage analysis, and antibiofilm assays. Characterization revealed a distinct absorption peak at 440 nm in UV-visible spectroscopy, spherical morphology under SEM, and the presence of copper in EDX analysis. TEM revealed nanoparticle dimensions of approximately 10-12 nm. In antibacterial assays, TCF-CuONPs displayed significant efficacy, with Pseudomonas aeruginosa exhibiting heightened susceptibility. This study successfully synthesized eco-friendly copper oxide nanoparticles using T. chebuladried fruit extract and thoroughly characterized their structural and compositional attributes. CuONPs exhibited substantial antibacterial potency against specific wound pathogens, indicating their potential in wound management applications. These findings contribute to the development of sustainable antibacterial solutions with implications for healthcare and environmental sustainability. Further research can delve into the mechanisms and broader applications of CuONPs based on the specific experimental outcomes.

Electrodeposition of CoNi Bimetallic Catalyst for Ethanol Electrooxidation Application

Platinum is potentially employed as a catalyst in direct ethanol fuel cells (DEFCs). However, its scarcity and susceptibility to carbon monoxide poisoning give rise to novel challenges necessitating resolution. Transition metals such as nickel and cobalt are regarded as highly auspicious catalysts for DEFCs due to their perceived potential to reduce the expenditure associated with the synthesis procedure. In the present investigation, the synthesis of a cobalt-nickel (CoNi) catalyst with bimetallic properties was effectively accomplished through the electrodeposition technique utilizing the stimulator mode. Subsequently, an evaluation was conducted to assess the catalyst's proficiency in ethanol electrooxidation. The CoNi samples underwent comprehensive characterization through the utilization of various analytical techniques, namely X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental dispersive X-ray analysis, and electrochemical impedance spectroscopy (EIS). The XRD analysis confirmed the formation of CoNi, while the SEM characterization demonstrated that the CoNi samples exhibited a homogeneous morphological feature. The impedance measured by the EIS technique displayed a resistance to charge transfer value of 21.21 kΩ, while the solution resistance value amounted to 66.67 kΩ. The catalytic efficiency of the specimens in ethanol electrooxidation was evaluated using the cyclic voltammetry technique, resulting in a peak current density of 3.14 mA/cm2 proving the potential of bimetallic CoNi to be a low-cost catalyst for ethanol electrooxidation process.

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.

Synthesis of Imino Stabilized Iron Oxide Nanosensor for Selective Detection of Lead Ions

The present work describes the successful preparation of iron oxide nanoparticles (NSB1) stabilized with 4-((2-hydroxybenzylidene)amino)benzoic acid. The characterization has been achieved through ultraviolet visible (UV-Vis), fourier transform infra-red (FTIR) spectroscopy and scanning electron microscopy (SEM) with electron dispersive X-ray elemental analysis (EDX). These magnetic nanoparticles have exhibited significant chemosensing properties in the aqueous media to screen Cr3+, Cd2+, Li+, Co2+, Al3+, Pb2+, Ni2+ and Sr2+ ions. However, lead (Pb2+) ions have shown the highest selectivity as compared to other metal ions without any interference in the competitive ion study. The detection limit of Pb2+ ions was found to be 1.7 µM by this nanosensor. The binding ratio and stoichiometry was found to be 1:1 as measured by Job’s plot. The binding strength was also computed through Benesei-Hildebrand equation.

Directional dependent magnetization in BaFe12O19 thin film

The thin film of BaFe12O19 (BHF) on a silicon substrate has been prepared by the pulse laser deposition method. The crystal structure, morphology, elemental analysis, and magnetic properties have been investigated by using X-Ray Diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy, elemental dispersive x-ray analysis, and vibrating sample magnetometry, respectively. The Rietveld refinement of XRD patterns of BHF powder has been performed to study the crystal structure and lattice parameters. Peak shifting in XRD pattern and Raman spectra for the thin film have been observed compared to that of powder sample. It could be due to the existence of stress at the interface of film and substrate. The magnetic hysteresis loops (M-H loops) of BHF thin film and powder were traced at 60 K and 300 K. The M-H loops of BHF suggest the hard and soft magnetic nature of powder and thin film, respectively. There is a large difference has been observed between saturation magnetization measured by applying a magnetic field parallel and perpendicular directions of the thin film. The bifurcation in zero field cooling (ZFC) and field cooling (FC) magnetization curves reveals the magnetic frustration in the thin films.

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.

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.

Effect of Substrate Temperature on Structural, Electrical and Optical Properties of Sprayed Tin Selenide Thin Films Applicable for Photovoltaic Measurements

Thin films of Tin selenide (SnSe) have been prepared on glass substrates at different temperatures in the range of 250 °C–375 °C in steps of 25 °C for optimization were discussed. The deposited tin selenide thin films were characterized using X-ray diffraction analysis (XRD), Elemental dispersive X-ray analysis (EDAX), Scanning electron microscopy (SEM), Optical absorption, Photoluminescence (PL), Raman spectroscopy and electrical measurements. From XRD analysis a single-phase tin selenide thin film having orthorhombic crystalline structure with crystallite size of 17 nm to 62 nm were investigated. The surface morphology revealed the presence of uniformly distributed spherical grains of SnSe thin films without pores and voids. Optical absorption spectrum revealed a direct band gap of 1.15 eV and having very high absorption coefficient (˃104/cm) was calculated. The Raman scattering analysis confirmed the presence of B3g and Ag vibrational modes of SnSe thin films. PL studies revealed a strong luminescence peak near-band-edge (NBE) emission at 785 nm due to recombination of bound excitons. Photoconductivity characteristics of SnSe thin films were due to the existence of continuous distribution of localized states in the band gap data. Thus tin selenide thin films were used as an absorber layer in the photovoltaic application.

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.

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.