Search

A novel magnetic semiconductor nanocomposite based on functionalized magnetite nanoparticles (MNPs) embedded in a matrix of bismuth ferrate compound (BFO) was obtained in a single step for the first time using the microwave-assisted hydrothermal synthesis. The synthesis method allows obtaining multiferroic BFO small particles and MNPs–BFO nanocomposites with optical activity in the near-infrared region (1.6 eV) due to d–d charge transfer transitions on Fe(III) ion orbitals. The functionalized MNPs exhibit strong superparamagnetic behavior with blocking temperature TB near room temperature and high saturation magnetization of MS = 59 emu/g, attributed to ferrimagnetic nano-monodomains with critical size. Meanwhile, the synthesized BFO shows an unusual superparamagnetic behavior with TB = 20 K and an interesting magnetic transition from the blocked superparamagnetic state to quantum superparamagnetic state at a critical temperature Tc = 11 K, attributed to ferromagnetic very small, critical size nano-monodomains. As result, the MNPs–BFO nanocomposite shows a superparamagnetic behavior at room temperature which, in close connection with its optical properties, makes it an excellent candidate for infrared magneto-optical applications.

Therapeutic drugs for Alzheimer’s disease have been extensively studied due to its recurrence and abundance among neurodegenerative diseases. It is thought that the accumulation of amyloid precursor protein (APP) products, a consequence of an up-regulation of the β-site APP-cleaving enzyme 1 (BACE1), is the main triggering mechanism during the early stages of the disease. This study aims to explore the ability of a multifunctional conjugate based on magnetite nanoparticles for the cellular delivery of siRNA against the expression of the BACE1 gene. We immobilized the siRNA strand on PEGylated magnetite nanoparticles and investigated the effects on biocompatibility and efficacy of the conjugation. Similarly, we co-immobilized the translocating protein OmpA on PEGylated nanoparticles to enhance cellular uptake and endosomal escape. BACE1 suppression was statistically significant in HFF-1 cells, without any presence of a cytotoxic effect. The delivery of the nanoconjugate was achieved through endocytosis pathways, where endosome formation was likely escaped due to the proton-sponge effect characteristic of PEGylated nanoparticles or mainly by direct translocation in the case of OmpA/PEGylated nanoparticles.

Real-time detection of heavy metal traces from industrial waste is key to control any potential environmental pollution by early critical point intervention. This opens a market niche for real-time, portable, and cost-efficient devices for environmental and biosafety monitoring. Despite the rapid growth of heavy metal monitoring as a research field, and the promising performance of an increasing number of novel platforms reported, the chances to transfer the lab-scale platforms developed to successful commercialization stages are dramatically low. This work proposes for the first time the use of ink-jet printed gold electrodes as a reliable, stable and fully-scalable approach for aptamer-based detection of mercury (Hg2+) traces in water and organic solvents. A controlled fabrication process was demonstrated by keeping the 90% of the charge transfer (RCT) values obtained from the as-fabricated electrodes (n = 11) within ± 1 SD (RSD = 2.92%) from the mean value and following a mesokurtic normal-like distribution (p = 0.905). The as-fabricated platform achieved a LOD of 0.01 ppm in water and enhanced sensitivity of 2-fold when tested in organic solvents, with a LOD of 0.005 ppm which is far below the minimal sensitive required for practical implementation, according to the EPA stipulations. Finally, the aptamer-based gold ink-jet printed platform provided with enough evidence to state that the signal collected from Hg2+ was significantly different (p

BiOCl/BiVO4 photocatalysts with different ratios of gold particles were synthesized by a facile method at room temperature. The gold was in situ incorporated on the BiOCl/BiVO4 powders through the chemical reduction of HAuCl4 using ascorbic acid as reducing agent. X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and UV–Vis diffuse reflectance spectroscopy were conducted to perform the textural, structural and composition characterizations of the materials; while their photoactivities were evaluated using the methyl orange degradation under visible-light irradiation. The detailed morphology and microstructure of the 1.50Au-(BiOCl/BiVO4) catalyst reveals nanometer and micrometer sized particles in a range from 20 to 500 nm with sphere and elongated-like shapes. Polycrystalline features are observed with preferred (121) surface orientation and interplanar distance values corresponding to (112), (004) and (022) planes of monoclinic BiVO4, while (011), (110), (102) planes can be related to tetragonal BiOCl with the direction (111). The surface chemical analysis showed that the most active Au-(BiOCl/BiVO4) catalyst presents the highest V4+/V5+ ratio (0.85), a 43 at.% BiOCl content and a percentage of Au-decoration of about 1 at.%. A synergic behavior between these chemical compositions enhances the MO photocatalytic degradation. It was found that photodegradation rates strongly relied on the gold content, and the Au-(BiOCl/BiVO4) photocatalyst was highly stable after six reuses and easy to be recovered by centrifugation. A possible electronic transfer mechanism in the different as-synthesized photocatalysts upon visible illumination is proposed, thus elucidating the roles of Au, BiOCl and BiVO4 components. Presumably, the synergistic interaction arising between semiconducting and metallic nanoparticles induces the charge separation responsible for the enhanced photocatalytic behavior.

This study focuses on examining the isomerization of allyl alcohol using ruthenium (Ru) supported on alumina as a heterogeneous catalyst. The synthesized Ru/Al solids were characterized by various characterization techniques. The content of Ru was estimated by the energy dispersive x-ray technique. The x-ray diffraction (XRD) confirmed the presence of phases in the support and active species in the catalysts. The surface area of the support after Ru impregnation and the pore volume were determined by nitrogen physisorption. The analysis of programmed temperature (TPR and TPO) shows different redox sites which is confirmed by XPS. The catalytic results suggest a dependence on the amount of available metallic Ru, as well as the importance of the continuous regeneration of the metal using H2 to achieve a good conversion of the allyl alcohol. For comparison purposes, the commercial Ru on alumina 5% (CAS 908142) was used. The results show up to 68% alcohol conversion and 27% yield of the isomerization product using Ru(1,5.4h)/Al catalyst in comparison with 86% conversion and 39% yield of the isomerization product using CAS 908142. In contrast, our catalysts always presented higher TOF values (149–160) in comparison with CAS 908142 (101).

The inkjet printing of metal electrodes on polymer films is a desirable manufacturing process due to its simplicity but is limited by the lack of thermal stability and serious delaminating flaws in various aqueous and organic solutions. Kapton, adopted worldwide due to its superior thermal durability, allows the high-temperature sintering of nanoparticle-based metal inks. By carefully selecting inks (Ag and Au) and Kapton substrates (Kapton HN films with a thickness of 135 μm and a thermal resistance of up to 400 °C) with optimal printing parameters and simplified post-treatments (sintering), outstanding film integrity, thermal stability, and antidelaminating features were obtained in both aqueous and organic solutions without any pretreatment strategy (surface modification). These films were applied in four novel devices: a solid-state ion-selective (IS) nitrate (NO3-) sensor, a single-stranded DNA (ssDNA)-based mercury (Hg2+) aptasensor, a low-cost protein printed circuit board (PCB) sensor, and a long-lasting organic thin-film transistor (OTFT). The IS NO3- sensor displayed a linear sensitivity range between 10-4.5 and 10-1 M (r2 = 0.9912), with a limit of detection of 2 ppm for NO3-. The Hg2+ sensor exhibited a linear correlation (r2 = 0.8806) between the change in the transfer resistance (RCT) and the increasing concentration of Hg2+. The protein PCB sensor provided a label-free method for protein detection. Finally, the OTFT demonstrated stable performance, with mobility values in the linear (μlin) and saturation (μsat) regimes of 0.0083 ± 0.0026 and 0.0237 ± 0.0079 cm2 V-1 S-1, respectively, and a threshold voltage (Vth) of -6.75 ± 3.89 V.

This study focuses on examining the isomerization of allyl alcohol using ruthenium (Ru) supported on alumina as a heterogeneous catalyst. The synthesized Ru/Al solids were characterized by various characterization techniques. The content of Ru was estimated by the energy dispersive x-ray technique. The x-ray diffraction (XRD) confirmed the presence of phases in the support and active species in the catalysts. The surface area of the support after Ru impregnation and the pore volume were determined by nitrogen physisorption. The analysis of programmed temperature (TPR and TPO) shows different redox sites which is confirmed by XPS. The catalytic results suggest a dependence on the amount of available metallic Ru, as well as the importance of the continuous regeneration of the metal using H2 to achieve a good conversion of the allyl alcohol. For comparison purposes, the commercial Ru on alumina 5% (CAS 908142) was used. The results show up to 68% alcohol conversion and 27% yield of the isomerization product using Ru(1,5.4h)/Al catalyst in comparison with 86% conversion and 39% yield of the isomerization product using CAS 908142. In contrast, our catalysts always presented higher TOF values (149–160) in comparison with CAS 908142 (101).

The elimination of cephalexin (CPX) using electro-generated Cl2-active on Ti/RuO2-IrO2 anode was assessed in different effluents: deionized water (DW), municipal wastewater (MWW) and urine. Single Ti/RuO2 and Ti/IrO2 catalysts were prepared to compare their morphologies and electrochemical behavior against the binary DSA. XRD and profile refinement suggest that Ti/RuO2-IrO2 forms a solid solution, where RuO2 and IrO2 growths are oriented by the TiO2 substrate through substitution of Ir by Ru atoms within its rutile-type structure. SEM reveals mud-cracked structures with flat areas for all catalysts, while EDS analysis indicates atomic ratios in the range of the oxide stoichiometries in the nominal concentrations used during synthesis. A considerably higher CPX degradation is achieved in the presence of NaCl than in Na2SO4 or Na3PO4 media due to the active chlorine generation. A faster CPX degradation is reached when the current density is increased or the pH value is lowered. This last behavior may be ascribed to an acid-catalyzed reaction between HClO and CPX. Degradation rates of 22.5, 3.96, and 0.576 μmol L−1 min−1 were observed for DW, MWW and urine, respectively. The lower efficiency measured in these last two effluents was related to the presence of organic matter and urea in the matrix. A degradation pathway is proposed based on HPLC-DAD and HPLC-MS analysis, indicating the fast formation (5 min) of CPX-(S)-sulfoxide and CPX-(R)-sulfoxide, generated due the Cl2-active attack at the CPX thioether. Furthermore, antimicrobial activity elimination of the treated solution is reached once CPX, and the initial by-products are considerably eliminated. Finally, even if only 16% of initial TOC is removed, BOD5 tests prove the ability of electro-generated Cl2-active to transform the antibiotic into biodegradable compounds. A similar strategy can be used for the abatement of other recalcitrant compounds contained in real water matrices such as urine and municipal wastewaters.

Evidence to what it is identified in the literature as “active chlorine” in indirect oxidation processes occurring on Ti/ZrO 2 -RuO 2 -Sb 2 O 3 anodes is provided in this study. To discriminate such behavior, different catalysts are prepared using the Pechini method varying ZrO 2 content, at different Zr/Ru molar ratios: 1, 0.5 and 0.3. The characterization of the materials using X-ray photoelectron spectroscopy (XPS) reveals that no solid solution (Ru-Zr) or any doping that affects the crystalline phase of Zr are obtained, while Sb 2 O 3 was surface-segregated from the bulk to the anode surface affecting the outmost 3–5 nm surface layers. There are enormous impacts on the catalytic activity and adsorption properties of the structures as ZrO 2 content is increased. The presence of ZrO 2 and Sb 2 O 3 shrink the number of favorable oxygen adsorption sites in Ti/ZrO 2 -RuO 2 -Sb 2 O 3 catalysts, whence the adsorption energies for oxygen-metal interactions became lower than for Ti/RuO 2 . Differential electrochemical mass spectroscopy (DEMS) and electrochemical experiments qualitatively indicate that a lower amount of ZrO 2 in the ternary electrode induce a better catalysis towards the oxygen evolution reaction (OER, O 2 production), while the ionic currents for C l O − and H C l O species drop. This behavior suggests that chloride oxidation needs to encompass the mitigation of the OER as the percentage of ZrO 2 is increased in the anode. Active chlorine could stem from H C l O a d s species since it was produced in larger amounts than C l O a d s − according to the pH of the electrolyte, and in adequate levels to generate the degradation of organic compounds.

As life expectancy continues to increase, the inevitable weakening and rupture of bone tissue have grown as concerns in the medical community, thus leading to the need for adhesive materials suitable for bone repair applications. However, current commercially available adhesives face certain drawbacks that prevent proper tissue repair, such as low biocompatibility, poor adhesion to wet surfaces, and the need for high polymerization temperatures. This work aims to develop an injectable and photo-responsive chitosan methacrylate/graphene oxide (ChiMA/GO) adhesive nanocomposite hydrogel of high biocompatibility that is easy to apply by simple extrusion and that offers the possibility for in situ polymer and physiological temperatures. The nanocomposite was thoroughly characterized spectroscopically, microscopically, rheologically, thermally, and through mechanical, textural, and biological assays to fully evaluate its correct synthesis and functionalization and its performance under physiological conditions that mimic those observed in vivo. In addition, a finite element analysis (FEA) simulation was used to evaluate its performance in femur fractures. Results suggest the material’s potential as a bioadhesive, as it can polymerize at room temperature, shows superior stability in physiological media, and is capable of withstanding loads from body weight and movement. Moreover, the material showed remarkable biocompatibility as evidenced by low hemolytic and intermediate platelet aggregation tendencies, and high cytocompatibility when in contact with osteoblasts. The comprehensive studies presented here strongly suggest that the developed hydrogels are promising alternatives to conventional bone adhesives that might be further tested in vivo in the near future.

A novel ferromagnetic state coexisting with ferroelectric ordering at room temperature in strained BiFeO 3 (BFO) thin films grown using a sputtering technique on La 0.7 Sr 0.3 MnO 3 /SiO 2 /Si(100) (LSMO/SOS) substrates is reported. The properties of BFO films with different thicknesses ( t BFO = 15, 50, 70, 120, and 140 nm) on 40 nm LSMO layers are explored. [012] out-of-plane highly textured BFO/LSMO stacks grew with rhombohedral structures. LSMO layers are nanostructured in nature, constituted by ferromagnetic single-domain nanoregions induced by the constrain of the SiO 2 surface, with T C ∼200 K and high coercive field ( H C ) of ∼1100 Oe at 2.5 K. BFO films grew epitaxially nanostructured on LSMO, exhibiting ∼4 nm spherical nanoregions. The BFO layers show typical antiferromagnetic behavior (in a greater volume fraction) when made thicker ( t BFO > 70 nm). The thinner films ( t BFO T C > 400 K, H C ∼ 1600 Oe for 15 nm and ∼1830 Oe for 50 nm. We propose that such ferromagnetic behavior is originated by the establishment of a new magnetic configuration in the Fe 3+ O Fe 3+ sublattice of the BFO structure, induced by strong hybridization at the interface as consequence of superexchange coupling interactions with the ferromagnetic Mn 3+ O Mn 3+ /Mn 4+ sublattice of LSMO. All BFO layers show excellent ferroelectric and piezoelectric properties (coercive field ∼ 740 kV/cm, and d 33 = 23 p.m./V for 50 nm; ∼200 kV/cm and 55 p.m./V for 140 nm), exhibiting 180° and 109° DWs structures depending on the thickness. Such multiferroic properties predict the potential realization of new magneto-electronic devices integrated with Si technology.

Core–shell YFeO3@Al2O3 structure was obtained using advanced synthesis process. YFeO3@Al2O3 assemble was achieved by coating individual YFeO3 particles with several nanometers thickness of alumina-shell. After that, the particles characterization and the thickness control of the magnetic core/alumina interface were investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Finally, the magnetic properties of the resulting system were investigated. We found that the alumina-shell thickness diminishes the magnetization values and enhance the exchange bias effect at low magnetic field. This fact is explained by the pinning the weak ferromagnetic and antiferromagnetic domains wall motion at the interface of the core/shell during the descending and ascending magnetization in the hysteresis curves. The results prove that the weak-ferromagnetic and the antiferromagnetic ordering not only coexist but also they are weakly coupled in YFeO3.

A Sb2O5 doped-Ti/RuO2-ZrO2 (Ti/SbRuZr) electrode is used to perform the abatement of ciprofloxacin (CIP, C17H18FN3O3). The catalyst was prepared using the Pechini method, and subsequently characterized by XRD, SEM-EDS, EIS and CV. The microstructural analysis of Ti/SbRuZr shows the formation of RuO2 (P42/mnm) and ZrO2 (P2/m) crystalline phases, with an average crystallite size about twice (61.2 nm) lower than Ti/RuO2 (109 nm). Additionally, SEM micrographs reveal that ZrO2 affects the morphological features of the deposited RuO2 layer, turning it into a more heterogeneous material. The electrode capacity was evaluated through the elimination of antibiotic activity (AA) of CIP, revealing that 83 and 45% of AA was removed using Ti/SbRuZr and Ti/RuO2, respectively at 0.19 A h L−1. According to CV analysis, the electrochemical mechanism for CIP degradation was found to proceed through active chlorine species (Cl2-active) on Ti/SbRuZr. This facile kinetics occurring on the ternary catalyst resulted from a high charge transfer resistance for oxygen evolution reaction, as revealed by EIS analysis. HPLC, HPLC-MS, and density functional theory were employed to propose a reaction pathway for CIP degradation. Findings from this work stands out prospective applications of anodic electrochemical oxidation to efficiently eliminate CIP, and the associated proliferation of antibiotic resistant microorganisms in aqueous media.

A survey has been made of 300 habitual consumers of the eight species of wild mushrooms most often consumed in the south of Spain. The eight species selected constitute over 95% of the intake of this food in the samples studied. The mean consumption per capita of mushrooms in Spain is of 10.4 kg/year, 8.6 kg of which are consumed during the season, which lasts from between 1 and 3 months. Male pickers from the Huelva province were those who presented the largest intake, their age group being highly influenced by the species. The consumption of each mushroom studied and the total intake were adjusted/fitted to exponential distributions. These distributions could be an effective tool for toxicological or nutritional studies since they permit the evaluation of exposure that makes it possible to calculate the probabilistic risk analysis and the contribution to the reference dietary intake, respectively, for this population group.

Dimensionally Stable Anodes (DSA) of Sb2O5-doped Ti/RuO2-ZrO2 are prepared by the Pechini method to perform the degradation of indigo carmine (IC) under conditions similar to textile wastewater effluents. XRD results along with Rietveld refinement reveal that the co-deposited phases on the DSA exhibit a tetragonal crystal structure (P4/mmm) for RuO2 and monoclinic structure (P2/m) for ZrO2. Degradation tests conducted in solutions containing 0.64 mM IC and 0.05 M NaCl using a filter-press reactor (FM01-LC) show that the degradation rate is faster and more efficient at 200 A m−2 with a flow rate of 5 L min−1, although the energy consumption is moderately higher. Under this condition, the pollutant is efficiently removed, and converted to aliphatic acid compounds of low molecular weight, as indicated by 90 % Chemical Oxygen Demand (COD), 22 % Total Organic Carbon (TOC) elimination, along with an Average Oxidation State (AOS) value equal to 3.0. The energy consumptions revealed that it is feasible to carry out the IC degradation under reasonable operating costs. Topological and Natural Bond Orbital (NBO) analyses are computed using density functional theory (DFT), and combined with experimental results to propose a reaction pathway for IC abatement.

The study determined total mercury (Hg) content of 10 wild edible mushroom species collected in southern Spain. Results indicated that the highest Hg level corresponded to Boletus aereus with 10.28 ± 2.92 mg/kg DW (dry weight), while the lowest Hg level was found in Terfezia arenaria with 0.09 ± 0.08 mg/kg DW. Regarding the anatomic parts of the mushrooms, caps showed significantly higher Hg concentrations than stems in B. aereus, Amanita caesarea and Macrolepiota procera. The percentage of contribution to the Provisional Tolerable Weekly Intake (PTWI) for Hg was also calculated. Based on consumption data in Spain (0.011 kg/person/week), %PTWI was calculated ranging between 0.06 and 3.5% for mean Hg levels. When a high level of consumption was assumed (0.100 kg/person/week), %PTWI ranged between 0.58 and 31%. Results suggest that wild edible mushrooms in southern Spain could contribute with high Hg levels to the Spanish diet. However, the lack of consumption data for wild edible mushrooms made it difficult to give more definitive conclusions; hence further studies including specific consumption data will be needed.

The ferroelectric and magnetic properties and the magnetoelectric coupling (MEC) effects of Pb(Fe0.5Nb0.5)O3 (PFN) thin films grown on SrRuO3/Si substrates by the radiofrequency (RF) magnetron sputtering technique were studied. Highly textured, single-phase films with [1 1 0] preferential orientation and different thicknesses were successfully grown. Electric (P–E) hysteresis loops showed excellent and almost constant values of the maximum (∼65 μC cm−2) and remanent (∼25 μC cm−2) polarizations from 4 K to room temperature. Ferromagnetic order in the low-temperature region (below 50 K) is reported for the first time in PFN and discussed. The maximum (∼3 emu g−1) and remanent (∼1.5 emu g−1) magnetization values were obtained. Magnetic field dependence of the ferroelectric hysteresis loops was investigated for temperatures of between 4 and 100 K. Coexistence of ferroelectricity, magnetism and spin crossover phenomena were observed, and a significant direct DC MEC effect expressed by the coefficient α = ΔPr/ΔH with maximum value of 120 pC cm−2 Oe−1 at 4 K is reported.

Studies of structural and dielectric properties of lead-free perovskite K0.5Na0.5NbO3 (KNN) ceramics obtained by the substitution of 5 at% of La and Ti for ions in the A-site and B-site, respectively, and sintered at different temperatures between 1100°C and 1190°C, are presented. X-ray diffraction patterns show the successful formation of an orthorhombic perovskite phase similar to that of pure KNN. The effect of doping and sintering temperature on the dielectric properties of the resulting ceramics is discussed. Simultaneous substitution of La and Ti into the KNN (KNNLaTi) causes a shift in the ferroelectric–paraelectric phase transition temperature from that of pure KNN (420°C) to considerably lower ones (81 to 110°C) for the modified compounds. A particularly important result is the appearance of a single peak in the permittivity vs. temperature curve associated with the ferroelectric–paraelectric phase transition, where the KNNLaTi compound changes from orthorhombic to cubic structure, instead of the two reported for pure KNN. This transition exhibits the characteristics of a normal diffuse phase transition with an incipient relaxer behavior.

A study of the ferroelectric and magnetic properties and of the magnetoelectric coupling effects of Pb(Fe0.5Nb0.5)O3 (PFN) thin films, grown on SrRuO3/Si [(100) or (111)] substrates by the rf-magnetron sputtering technique, is presented. Structural, morphological, and compositional characterization was realized using the XRD, AFM, XPS, and TEM techniques. Highly textured single phase films with different thickness (from 45 to 270 nm) were successfully grown without Fe2+ presence. A vertically [110] oriented grainy structure was observed. Polarization vs. electric field (P-E) hysteresis loops exhibit excellent and almost constant values of the maximum (∼ 60 μC/cm2) and remanent (∼ 22 μC/cm2) polarizations in the temperature range from 4 K to room temperature; small values of the coercive field, characteristic of soft ferroelectric materials, are observed in these samples. Measurements of the zero-field cooled (ZFC) and field cooled (FC) magnetization behavior and magnetic (M-H) hysteresis loops were realized at different temperatures between 5 and 300 K. Proof of the existence of ferromagnetic order in the low temperature region (below to 50 K) is discussed and reported for the first time. Values of the maximum (∼ 3 emu/g) and remanent (∼ 1.5 emu/g) magnetizations were obtained. dc magnetic field dependence of the ferroelectric hysteresis loops are shown as evidence of the magnetoelectric coupling.

Evidence to what it is identified in the literature as “active chlorine” in indirect oxidation processes occurring on Ti/ZrO2-RuO2-Sb2O3 anodes is provided in this study. To discriminate such behavior, different catalysts are prepared using the Pechini method varying ZrO2 content, at different Zr/Ru molar ratios: 1, 0.5 and 0.3. The characterization of the materials using X-ray photoelectron spectroscopy (XPS) reveals that no solid solution (Ru-Zr) or any doping that affects the crystalline phase of Zr are obtained, while Sb2O3 was surface-segregated from the bulk to the anode surface affecting the outmost 3-5 nm surface layers. There are enormous impacts on the catalytic activity and adsorption properties of the structures as ZrO2 content is increased. The presence of ZrO2 and Sb2O3 shrink the number of favorable oxygen adsorption sites in Ti/ZrO2-RuO2-Sb2O3 catalysts, whence the adsorption energies for oxygen-metal interactions became lower than for Ti/RuO2. Differential electrochemical mass spectroscopy (DEMS) and electrochemical experiments qualitatively indicate that a lower amount of ZrO2 in the ternary electrode induce a better catalysis towards the oxygen evolution reaction (OER, O2 production), while the ionic currents for and species drop. This behavior suggests that chloride oxidation needs to encompass the mitigation of the OER as the percentage of ZrO2 is increased in the anode. Active chlorine could stem from species since it was produced in larger amounts than according to the pH of the electrolyte, and in adequate levels to generate the degradation of organic compounds.

Multiferroic properties are found in the Yttrium iron garnet (YIG) modified with Bi3+. The X-ray diffraction pattern shows that the Bi3+ ion is completely soluble up to one-third of the Y molar content forming the Y2BiFe5O12 compound as a single phase. Structural analysis did not show signals of other incipient non-centrosymmetric phases in the compound. However, the dielectric and polarization studies clearly exhibit a typical relaxor ferroelectric behavior at room temperature where the maxima of the broad permittivity peaks shift with frequency. The quadratic diffuseness coefficient obtained from the modified Curie–Weiss law suggests polar nanoregion switching in a broad temperature range. Using the Vogel–Fulcher relationship, the activation energy and freezing temperature were found to be 243.1 meV and 322.6 K, respectively. Here, the main contribution to relaxation comes from thermally activated reorientation of the dipole moments, as confirmed by the well-defined hysteresis loops in the P-E measureme...

This paper presents a new non-isolated high step-up topology by connecting two buck-boost DC/DC converters in the interleaved form. The presented topology has two identical buck-boost converters connected in a parallel-input, series-output manner for boosting the output voltage. This new topology can serve as an alternative to the typically used transformer isolated converter topology. A low-frequency modeling technique MISSCO is used to model and analyse the converter and simulations results are shown.

A novel synthesis method was employed to obtain a new family of lead-free compounds with the general formula: Ba1-yLn2y / 3Ti0.91Zr0.09O3 (Ln= lanthanide element). The thin films were deposited by RF-magnetron sputtering under high-oxygen pressure on different substrates at 873 K. The crystalline phases were studied via x-ray diffraction, showing the 001 epitaxial reflections corresponding to perovskite single-phase compounds. The films revealed high homogeneity and stoichiometries corresponding to BLnZT (Ln=Nd, La). Deposited thin films showed a smooth surface. Ferroelectric measurements through hysteresis curves were obtained in Ba0.90La0.067�0.033Ti0.91Zr0.09O3, capacitor structures showing clear ferroelectric behavior with Pr, Ps and Ec of 11.9 µC/cm², 36.8 µC/cm² and 38.6 kV/cm, respectively.

A group of moderately halophilic bacteria able to degrade aromatic organic compounds contaminating hypersaline habitats in southern Spain have been isolated and characterized. The taxonomic position of these strains was determined using phenotypic, phylogenetic and genotypic methods. The G+C content of their DNA ranged from 61·0 to 62·9 mol%. DNA–DNA hybridization studies showed that they constitute a genospecies, having DNA–DNA hybridization values of 90–100 %. Analysis of the complete 16S rRNA gene sequence revealed a high level of similarity with members of the genus Halomonas, sharing 98 % 16S rRNA gene sequence similarity with the type strains of Halomonas salina and Halomonas halophila. However, phenotypic differences and the low level of DNA–DNA hybridization suggest the placement of these strains as a novel species within the genus Halomonas. The name Halomonas organivorans sp. nov. is proposed, with strain G-16.1T (=CECT 5995T=CCM 7142T) as the type strain. This novel species of Halomonas is characterized by its ability to use a wide range of organic compounds (benzoic acid, p-hydroxybenzoic acid, cinnamic acid, salicylic acid, phenylacetic acid, phenylpropionic acid, phenol, p-coumaric acid, ferulic acid and p-aminosalicylic acid), and it could be useful for the decontamination of polluted saline habitats.

In this study, (011)-highly oriented Sr, Nb co-doped BiFeO3 (BFO) thin films were successfully grown on SrRuO3/Si substrates by rf-magnetron sputtering. The presence of parasite magnetic phases was ruled out based on the high resolution x-ray diffraction data. BFO films exhibited a columnar-like grain growth with rms surface roughness values of 5.3 nm and average grain sizes of 65-70 nm for samples with different thicknesses. Remanent polarization values (2Pr) of 54 lC cm 2 at room temperature were found for the BFO films with a ferroelectric behavior characteristic of an asymmetric device structure. Analysis of the leakage mechanisms for this structure in negative bias suggests Schottky injection and a dominant Poole-Frenkel trap-limited conduction at room temperature. Oxygen vacancies and Fe3þ/Fe2þ trap centers are consistent with the surface chemical bonding states analysis from x-ray photoelectron spectroscopy data. The (011)-BFO/ SrRuO3/Si film structure exhibits a strong magnetic interaction at the interface between the multiferroic film and the substrate layer where an enhanced ferromagnetic response at 5 K was observed. Zero-field cooled (ZFC) and field cooled (FC) magnetization curves of this film system revealed a possible spin glass behavior at spin freezing temperatures below 30 K depending on the BFO film thickness.