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Silver–palladium (Ag/Pd) bimetallic nanoparticles were synthesized by greener way using Catharanthus leaf extract. The synthesized silver/palladium bimetallic nanoparticles were used to degrade the safranin O textile dye through photo catalytic activity and the free radical scavenging property was evaluated by DPPH assay test. Silver/Palladium bimetallic nanoparticles were synthesized by biogenic reduction method using silver nitrate and palladium chloride precursors assisted with CRL extract. The synthesized Ag/Pd bimetallic nanoparticles' morphological and particle size were evaluated by the SEM/TEM image. The particle size was found to be within the nanoscale range of 15–30 nm. The 98% maximum dye degradation for 40 min time duration was achieved by the photocatalytic activity of silver/palladium bimetallic nanoparticles through UV light irradiation on safranin O textile dye and simultaneously antioxidant activity of silver/palladium bimetallic nanoparticles was also tested through DPPH assay test. The free radical scavenging efficiency was calculated for extract and extract with silver/palladium nanoparticles and was found to be 48.2% and 70.2%, respectively and revealed that the silver/palladium nanoparticles have 2.34 times higher scavenging activity when compared with Catharanthus leaf extract. [ABSTRACT FROM AUTHOR]

Herein, we present the facile synthesis of different content of chromium (Cr)-doped CdS quantum dots (Cr@CdS QDs) using microwave route within 15 min. The synthesized Cr@CdS QDs were investigated for structural, morphological, opto-dielectric, and electrical natures. X-ray diffraction confirms the monophasic hexagonal system of Cr@CdS and the sizes of crystallites are calculated to be 8.72, 7.04, 8.84, 6.56, 5.96, 6.52 and 6.99 nm for 0.0, 0.5, 1.0, 5.0, 10.0, 15.0, and 20.0 wt% Cr@CdS samples. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies reveal the quantum dots size spherical shape morphology of synthesized Cr@CdS samples and the size is noted in range of 8.5–8.1 nm. The lattice spacing and orientation of grown QDs was also evaluated by high-resolution TEM and Selected Area Electron Diffraction (SAED) pattern. Diffused reflectance spectra were recorded and Kubelka–Munk theory is employed to estimate the energy gap. The energy gap was estimated between 2.4 and 2.46 eV for Cr@CdS QDs. Photoluminescence (PL) emission spectra own an strong emission peak in both spectra recorded at two different excitation wavelengths and revealed that the PL emission intensity is quenched with Cr doping in CdS. Dielectric and ac electrical studies shows the dependence on frequency and Cr content doping, and constant values are enhanced from 14 to 17 at 4 MHz. The prepared Cr@CdS QDs will be highly useful as sensitizers in solar cell, spintronics, and optoelectronics. [ABSTRACT FROM AUTHOR]

MEMS-based tensile testing platforms are very powerful tools for the mechanical characterization of nanoscale materials, as they allow for testing of micro/nano-sized components in situ electron microscopes. In a typical configuration, they consist of an actuator, to deliver force/displacement, and a load sensor, which is connected to the sample like springs in series. Such configuration, while providing a high resolution force measurement, can cause the onset of instability phenomena, which can later compromise the test validity. In the present paper such phenomena are quantitatively discussed through the development of an analytical model, which allows to find a relationship between the rise of instability and the sensor stiffness, which is the key parameter to be optimized.

Highlights • Rare earth element Ce3+ doped CoFe 2 O 4 NPs were prepared by simple sol-gel combustion technique. • Cerium was successfully substituted into the spinel lattice without any distortion. • Powder XRD and SEM along with EDX studies confirmed the pure phase formation. • There was a substantial decrease in the crystallite size on doping with Ce3+. • Magnetic properties altered by the addition of Ce3+ in the CoFe 2 O 4 matrix. Abstract In this present study, we made an attempt for the different concentration of rare earth element (REE) Cerium (Ce3+) doped cobalt ferrite (CoFe 2 O 4) nanoparticles (NPs) were prepared by the simple sol-gel combustion technique. Cerium was successfully substituted into the spinel lattice without any distortion. It was analyzed the effect of Ce3+ ions doping on structural, morphological, magnetic properties and antibacterial activities using the various instrument techniques. Powder XRD and SEM along with EDX studies confirmed the pure phase formation Ce3+ doped CoFe 2 O 4 NPs and spherical shaped agglomerated nanoparticles morphology without any other impurity. The well resolved broad peaks in the XRD pattern clearly indicated the nanosized, single phased, cubic spinal nature of these samples. There was a substantial decrease in the crystallite size on doping with Ce3+. A more in-depth morphological study was facilitated using the TEM and SAED analysis. TEM investigation revealed random shaped, sharp edged nanoparticles with a normally facetted morphology. The presence of distinctive diffractions spots on the SAED pattern indicated the formation of nanoparticles that are highly crystalline in nature. The magnetic response of the Ce3+ doped CoFe 2 O 4 NPs was recorded at room temperature (RT) using the VSM technique. The magnetic properties have been seen to be altered by the addition of Ce3+ in the CoFe 2 O 4 matrix. The decrease in the saturation magnetization (M s , emu/g) with the increase in Ce3+ content rendered the synthesized sample applicable in field of antenna construction. This change will be also suitable for reducing the size of the antenna. The antibacterial activity of Ce3+ doped CoFe 2 O 4 nanoparticles was found to be enhanced with increase in Ce3+ doping level as it cause a reduction in the grain size. [ABSTRACT FROM AUTHOR]

Abstract Appropriate mechanical properties are essential for the use of biodegradable Mg-based alloys as structurally supporting materials. However, research studies on the evolution of the tensile fracture pathways and fracture characteristics of as-cast and as-extruded Mg-based alloys are limited. In this paper, the microstructures, tensile properties, fracture pathways and fracture characteristics of the as-cast, heat treated and hot-extruded Mg-1.59Nd-2.91Zn-0.05Zr-0.35Mn (NZKM) alloys were systematically investigated. The results indicated that the hot-extruded NZKM alloy exhibits good mechanical properties with a yield strength and an elongation reaching 212 MPa and 30.7%, respectively. These excellent properties were attributed to its special multiscale microstructure consisting of an α-Mg matrix (2–10 μm), eutectic compound β-Mg 4 Zn 7 (2–10 μm) together with a high density of dispersed nanoscale precipitates, that provide solid solution strengthening, grain boundary strengthening and precipitation strengthening effects. The fracture patterns changed with the evolution of the microstructures. Intergranular and transgranular cleavage fractures were changed to ductile fractures by hot extrusion. Graphical abstract Image 1 Highlights • Hot extrusion enhanced mechanical properties of Mg-Nd-Zn-Zr-Mn (NZKM) alloy. • Great mechanical properties because of dislocations and deformation twins. • Morphologies of eutectic compounds and grain sizes affect fracture behaviors. [ABSTRACT FROM AUTHOR]

In this study we report the solventless synthesis of iron oxide through thermal decomposition of acetyl ferrocene as well as its mixtures with maliec anhydride and characterization of the synthesized product by various comprehensive physical techniques. Morphology, size and structure of the reaction products were investigated by scanning electron microscopy, transmission electron microscopy and X-ray powder diffraction technique, respectively. Physical characterization techniques like FT-IR spectroscopy, dc magnetization study as well as 57 Fe Mössbauer spectroscopy were employed to characterize the magnetic property of the product. The results observed from these studies unequivocally established that the synthesized materials are hematite. Thermal decomposition has been studied with the help of thermogravimetry. Reaction pathway for synthesis of hematite has been proposed. It is noted that maliec anhydride in the solid reaction environment as well as the gaseous reaction atmosphere strongly affect the reaction yield as well as the particle size. In general, a method of preparing hematite nanoparticles through solventless thermal decomposition technique using organometallic compounds and the possible use of reaction promoter have been discussed in detail. [ABSTRACT FROM AUTHOR]

The re-calcination of commercial metakaolin was carried out and structural changes were observed in relation to pozzolanic activity and specific surface area in temperature range 500–1000 °C. The re-calcined metakaolins were characterized by XRD, SAXS, SEM, TEM in relation to structure state and reactivity variation based on Chapelle test. The re-calcination led to ∼40% rise of reactivity in the range of 650–800 °C. Considering the structural changes the mullite phase crystallization and partial sintering of the particles caused rapid decreasing of reactivity. SAXS spectrum revealed the formation of new phase already at annealing temperature 800 °C. [ABSTRACT FROM AUTHOR]

Abstract: A necessary condition to include nanoscale materials in the design of high-performing as well as reliable electrical and electromechanical devices is the availability of a sufficiently deep knowledge of their mechanical behavior. Up to date, the most powerful tools for mechanical characterization of nanosamples are properly designed microelectromechanical systems (MEMS), due to their compatibility with scanning/transmission electron microscopy (SEM/TEM) and high resolution force/displacement measurements. Herein, we report about the design of a MEMS platform for in situ SEM tensile testing of nanoscale samples. This is characterized by a very compact structure, based only on a bent beam electrothermal actuator, which performs both actuating and sensing functions. The size of the structural components of the present device is chosen with the aim of testing ceramic nanowires, but the resulting configuration can be applied also for other material samples. [Copyright &y& Elsevier]

Abstract: The aim of this study was the synthesis of mixed or coated multicomponent alumina–silica particles by chemical vapour deposition method in a tube flow reactor. The particles were produced by simultaneous thermal decomposition of aluminum tri-sec-butoxide and tetraethylorthosilicate in one reactor. The particle production was monitored by Differential Mobility Particle Sizer, composition of particles was analysed by energy dispersive X-ray analysis, morphology by scanning/transmission electron microscopy and crystallinity by selected area electron diffraction. In dependence on experimental conditions, the particles produced were either alumina particles with intermixture of silica, or they were coated by silica, or it was a mixture of particles of various compositions. The particles were often agglomerates of the primary nanoparticles and were partially crystalline. [Copyright &y& Elsevier]

Abstract: Between 1952 and 1963, the Abbé Glory conducted excavation in the Lascaux Cave. He discovered many artefacts useful for the Prehistoric painter. Today this material is kept in the “Institut de Paléontologie Humaine” in Paris. Some of this material, as well as the painting matter of the “Blazons” of the Black Cow Panel of the Nef, were examined and analysed by electron microscopy: SEM and TEM. Yellow, ocher and red pigments are iron oxides and black pigments are manganese oxides. The results indicate that the pigments were by no means heated, nor associated with any extender. Nevertheless the variety of the raw matter indicates a real strategy to exploit nature in order to match the desired hue and the texture of the painted panel. [Copyright &y& Elsevier]

The combination of different techniques (DR UV–vis, 51V NMR, UV-Raman, FTIR, and H2-TPR) in the characterization of vanadia supported on mesoporous SBA-15 catalysts shows that the dispersity and the nature of the vanadium species depend strongly on the V loading. In dehydrated catalysts with V contents lower than 2.8 wt%, vanadium is mainly in a tetrahedral environment. Higher V contents in the catalyst lead to the formation of polymeric V2O5-like species. Textural, SEM/TEM, and XRD results indicate that the ordered hexagonal mesoporous structure with large pore diameters of the support is retained upon the vanadium incorporation, and therefore high surface areas were obtained on the final catalysts. Vanadium species anchored to the surface show structural properties similar to those on mesoporous V-MCM and conventional V...SiO2 catalysts, but a higher surface concentration of isolated or low polymeric VOx species could be achieved on the V-SBA samples. The number and nature of the acid sites also change with the vanadium loading. The superior performance of the present mesoporous SBA-15 catalysts in the oxidative dehydrogenation of propane has been attributed to a higher dispersion of V species achieved on the SBA-15 support with large pore diameters as well as the low surface acidity of the catalyst. [Copyright &y& Elsevier]

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A detailed characterization of the mineralogy corresponding to the low-grade diagenetic-metamorphic sequence of the clastic rocks from the Beni Mezala antiform has allowed the processes implied in their origin to be stablished, integrating them in the geodynamic evolution of the Rif-Betic mountain range during the Alpine orogeny. A progressive evolution towards chemical and textural equilibrium was observed. The illite "crystallinity" (CIS) ranges from diagenetic-lower anchizone in Ghomaride complex (CIS: 1.50–0.37 Δ°2θ) to epizone in the deepest Federico units (CIS: 0.29–0.21 Δ°2θ). The main phyllosilicates in the diagenetic samples are illite (2M1-1M polytypes) and kaolinite, with mixed-layer illite/smectite and chlorite, but the mixed layers disappear in the lower anchizone samples, which show sudoite and dickite. Pyrophyllite is also present in the upper anchizone (0.43–0.29 Δ°2θ) whereas the epizone samples show muscovite (2M1-3T polytypes), chlorite, paragonite, and intermediate micas. The chlorite geothermometers give a T range of 150 to 400 °C, and the b parameter of 2M1 micas (8.992–9.029 Å) indicates low to intermediate pressure regional metamorphism (1–3 kbar) although the wide range of phengitic substitution in micas and the 3T polytype suggest a wider pressure range in coherence with the clockwise PTt evolution for the Rif Cordillera during the Alpine orogeny. [ABSTRACT FROM AUTHOR]