Sono-catalytic degradation and fast mineralization of p-chlorophenol: La0.7Sr0.3MnO3 as a nano-magnetic green catalyst

La_0.7Sr_0.3MnO₃ (LSMO) nanoparticles with a perovskite structure were prepared by a combination of ultrasound and co-precipitation method. The synthesized catalyst was characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy. The catalytic performance of the catalyst was evaluated for the degradation of 4-chlorophenol in the presence and in the absence of ultrasound. The degradation has been studied at different temperatures, pH, catalyst dosage, and initial concentration of 4-chlorophenol. The results have shown that the degradation efficiency was higher in the presence of ultrasound than its absence under the mild conditions. More than 88% decrease in the concentration and 85% decrease in the TOC for 4-chlorophenol could be achieved in a short time of sonication with respect to the conventional method. This behavior could be attributed to the cavitation process which followed by a high mass transfer on the catalyst with high surface area. These conditions led to facilitate the removal of pollutant from aqueous solution. The results also indicated that the catalyst without recalcination can be used successfully up to five consecutive cycles without any significant loss in activity in the presence and in the absence of ultrasound. In addition, the most important is the magnetic property of the nanoparticles which separated easily from aqueous solution by an external magnetic field.     

High-performance sono/nano-catalytic system: Fe3O4@Pd/CaCO3-DTT core/shell nanostructures,a suitable alternative for traditional reducing agents for antibodies

Herein, a novel heterogeneous nanoscale reducing agent for antibody cleavage, made of iron oxide nanoparticles, silica network, palladium on calcium carbonate (10%), and dithiothreitol (Fe₃O₄@Pd/CaCO₃-DTT), is presented as a substantial alternative for traditional homogeneous analogues. Conventionally, antibody fragmentation is accomplished using reducing agents and proteases that digest or cleave certain portions of the immunoglobulin protein structure to provide active thiol sites for drug tagging aims. Then, dialysis process is needed to separate excess chemical structures and purify the reduced antibody. In this work, we have made an effort to design a suitable heterogeneous tool for protein cleavage and skip the dialysis process for purification of the reduced antibody. In this regard, firstly, various preparation methods including microwave irradiation, reflux and ultrasonication have been precisely compared, and it has been proven that the best result is obtained through 10 min ultrasound (US) irradiation using an US bath with 50 KHz frequency and 200 W L⁻¹ power density. Then, all the necessary structural analyses have been done and thoroughly interpreted for the final product. Afterward, the catalytic performance of Fe₃O₄@Pd/CaCO₃-DTT nanoscale system in the presence of US waves (50 KHz, 200 W) has been monitored using some disulphide derivatives. The NPs could be conveniently separated from the mixture through their substantial paramagnetic property. Thus, dialysis process in which various types of membranes are used is practically jumped after the reduction process. In this work, this is clearly demonstrated that there is a constructive synergistic effect between US waves and prepared Fe₃O₄@Pd/CaCO₃-DTT nanoscale reducing agent. Ultimately, trastuzumab (anti HER-2) antibody has been used to test the performance of the prepared Fe₃O₄@Pd/CaCO₃-DTT NPs in a real protein reduction reaction.     

Enhanced visible-light-driven photocatalytic performance for degradation of organic contaminants using PbWO4 nanostructure fabricated by a new,simple and green sonochemical approach

Water contamination has turned into a critical global concern that menaces the entire biosphere and has a notable effect on the lives of living beings and humans. As a proper and environmentally friendly solution, visible-light photocatalysis technology has been offered for water contamination removal. There is a strong interest in the design of the efficient catalytic materials that are photoactive with the aid of visible light. Herein, to fabricate a highly efficient photocatalyst for removal of organic pollution in water, a facile and swift sonochemical route employed for creation of the spindle shaped PbWO₄ nanostructure with the aid of an environmentally friendly capping agent (maltose) for the first time. To optimize the efficiency, dimension and structure of lead tungstate, various effective factors such as time, dose of precursors, power of ultrasound waves and kind of capping agents were altered. The attributes of PbWO₄ samples were examined with the aid of diverse identification techniques. The produced lead tungstate samples in role of visible-light photocatalyst were applied to remove organic pollution in water. The kinds of pollutants, dose and type of catalyst were examined as notable factors in the capability to eliminate contaminants. Very favorable catalytic yield and durability were demonstrated by spindle-shaped PbWO₄ nanostructure (produced at power of 60 W for 10 min and with usage of maltose). Usage of ultrasonic irradiation could bring to improvement of catalytic yield of PbWO₄ to 93%. Overall, the outcomes could introduce the spindle-shaped PbWO₄ nanostructure as an efficient substance for eliminating water contamination under visible light.     

金红石相Fe3+/TiO2结构与磁特性分子动力学模拟

结合共价作用与量子修正,采用分子动力学方法,模拟计算了300K常压下金红石相Fe3+/TiO2晶体结构及能量参数.结果表明,当掺杂量达5.7mol%时,晶胞参数a与晶胞体积明显增大,八面体共棱部分消失,(110)晶面中的阴离子精细结构逐渐消失,阴离子均方位移与体系能量也明显增大.此外,结构畸变易形成氧空位桥基团(Fe3+-[F心]-Ti4+), 而呈铁磁性,随掺杂量增加,该基团取向变化而易形成反铁磁性,所获得了模拟结果与磁特性与实验结果基本一致.     

Effective control of antibiotic resistance using a sonication-based combinational treatment and its application to fresh food

Antibiotics have been widely used to treat several infectious diseases. However, the overuse of antibiotics has promoted the emergence and spread of antibiotic resistant bacteria (ARB) in various fields, including the food industry. In this study, the antimicrobial efficacies of two conventional sterilization methods, mild heat, and sonication, were evaluated and optimized to develop a new strategy against ARB. Simultaneous mild heat and sonication (HS) treatment led to a significant reduction in viable cell counts, achieving a 5.58-log reduction in 4 min. However, no remarkable decrease in viable cell counts was observed in individually treated groups. Interestingly, the release of antibiotic resistance genes (ARGs) increased in a time-dependent manner in the heat-treated and HS-treated groups. The inactivation levels of ARGs increased as the HS treatment time increased from 2 to 8 min, and most ARGs were degraded after 8 min. In contrast, no significant inactivation of ARGs was observed in the heat-treated and sonication-treated groups after 8 min. These results reveal the synergistic effect of the combination treatment in controlling not only ARB but also ARGs. Finally, on applying this newly developed combination treatment to fresh food (cherry tomato and carrot juice), 3.97- and 4.28-log microbial inactivation was achieved, respectively. In addition, combination treatment did not affect food quality during storage for 5 days. Moreover, HS treatment effectively inactivated ARGs in fresh food systems.     

Ultrasound-assisted extraction of phenolic acids,flavonols, and flavan-3-ols from muscadine grape skins and seeds using natural deep eutectic solvents and predictive modelling by artificial neural networking

The objective of this study was to investigate the extraction efficiency of 9 natural deep eutectic solvents (NDES) with the assistance of ultrasound for phenolic acids, flavonols, and flavan-3-ols in muscadine grape (Carlos) skins and seeds in comparison to 75% ethanol. Artificial neural networking (ANN) was applied to optimize NDES water content, ultrasonication time, solid-to-solvent ratio, and extraction temperature to achieve the highest extraction yields for ellagic acid, catechin and epicatechin. A newly formulated NDES (#1) consists of choline chloride: levulinic acid: ethylene glycol 1:1:2 and 20% water extracted the highest amount of ellagic acid in the skin at 22.1 mg/g. This yield was 1.73-fold of that by 75% ethanol. A modified NDES (#3) consisting of choline chloride: proline: malic acid 1:1:1 and 30% water extracted the highest amount of catechin (0.61 mg/g) and epicatechin (0.89 mg/g) in the skin, and 2.77 mg/g and 0.37 mg/g in the seed, respectively. The optimal yield of ellagic acid in the skin using NDES #1 was 25.3 mg/g (observed) and 25.3 mg/g (predicted). The optimal yield of (catechin + epicatechin) in seed using NDES #3 was 9.8 mg/g (observed) and 9.6 mg/g (predicted). This study showed the high extraction efficiency of selected NDES for polyphenols under optimized conditions.     

One-pot solvent-free synthesis of 2,3-dihydro-2-substituted-1H-naphtho[1,2-e][1,3]oxazine derivatives using Fe3O4@nano-cellulose/TiCl as a bio-based and recyclable magnetic nano-catalyst

Molecular Diversity - The present study describes an efficient and environmentally benign protocol for the synthesis of 2,3-dihydro-2-substituted-1H-naphtho[1,2-e][1,3]oxazine derivatives....     

Synthesis of nanocomposites of iron oxide/gold (Fe3O4/Au) loaded on activated carbon and their application in water treatment by using sonochemistry: Optimization study

This paper focuses on the finding best operational conditions using response surface methodology (RSM) for Rhodamine123 (R123) and Disulfine blue (DSB) dyes removal by ultrasound assisted adsorption onto Au-Fe₃O₄ nanoparticles loaded on activated carbon (Au-Fe₃O₄ NPs-AC). The influences of variables such as initial R123 (X₁) and DSB concentration (X₂), pH (X₃), adsorbent mass (X₄) and sonication time (X₅) on their removal were investigated by small central composite design (CCD) under response surface methodology. The significant variables and the possible interactions among variables were investigated and estimated accordingly. The best conditions were set as: 4 min, 4.0, 0.025 g, 13.5 and 26.5 mg L⁻¹ for sonication time, pH, adsorbent weight, initial R123 and DSB concentration, respectively. At above conditions, the adsorption equilibrium and kinetic follow the Langmuir isotherm and pseudo-second-order kinetic model, respectively. The maximum monolayer capacity (Q_max) of 71.46 and 76.38 mg g⁻¹ for R123 and DSB show sufficiency of model for well presentation of experimental data.     

Synthesis of TiN/a-Si3N4 thin film by using a Mather type dense plasma focus system

A 2.3 kJ Mather type pulsed plasma focus device was used for the synthesis of a TiN/a-Si3N4 thin film at room temperature. The film was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The XRD pattern confirms the growth of polycrystalline TiN thin film. The XPS results indicate that the synthesized film is non-stoichiometric and contains titanium nitride, silicon nitride, and a phase of silicon oxy-nitride. The SEM and AFM results reveal that the surface of the synthesized film is quite smooth with 0.59 nm roughness (root-mean-square).     

光栅衍射多普勒效应位移测量的理论分析和实验结果

本文研究了一种利用光栅衍射的多普勒效应进行位移测量的新方法.文中进行了光路结构和测量原理的理论分析,得出测量公式,证明了用光栅拾取多路差拍信号的相位关系.实验结果表明,它具有高的信号质量,可有效地用于位移的精密测量.     

Excitation of ultrasonic Lamb waves using a phased array system with two array probes: Phantom and in vitro bone studies

Long bones are good waveguides to support the propagation of ultrasonic guided waves. The low-order guided waves have been consistently observed in quantitative ultrasound bone studies. Selective excitation of these low-order guided modes requires oblique incidence of the ultrasound beam using a transducer-wedge system. It is generally assumed that an angle of incidence, θ_i, generates a specific phase velocity of interest, c_o, via Snell’s law, θ_i = sin⁻¹(v_w/c_o) where v_w is the velocity of the coupling medium. In this study, we investigated the excitation of guided waves within a 6.3-mm thick brass plate and a 6.5-mm thick bovine bone plate using an ultrasound phased array system with two 0.75-mm-pitch array probes. Arranging five elements as a group, the first group of a 16-element probe was used as a transmitter and a 64-element probe was a receiver array. The beam was steered for six angles (0°, 20°, 30°, 40°, 50°, and 60°) with a 1.6-MHz source signal. An adjoint Radon transform algorithm mapped the time-offset matrix into the frequency-phase velocity dispersion panels. The imaged Lamb plate modes were identified by the theoretical dispersion curves. The results show that the 0° excitation generated many modes with no modal discrimination and the oblique beam excited a spectrum of phase velocities spread asymmetrically about c_o. The width of the excitation region decreased as the steering angle increased, rendering modal selectivity at large angles. The phenomena were well predicted by the excitation function of the source influence theory. The low-order modes were better imaged at steering angle ?30° for both plates. The study has also demonstrated the feasibility of using the two-probe phased array system for future in vivo study.     

In-beam Mössbauer study of 57Fe using a secondary 57Mn beam and ion implantation

We have succeeded in obtaining well-resolved M?ssbauer spectra of ⁵⁷Fe arising from short-lived ⁵⁷Mn ( T _1/2 = 1.45 min) in Si and KMnO₄. The M?ssbauer spectra of ⁵⁷Fe in Si are well fitted with a curve consisting of two singlet lines, one being assigned as the interstitial Fe atoms and the other as substitutional ones. The relative intensities of the two lines infer that 60% of ⁵⁷Fe ( ←⁵⁷Mn) atoms land at the interstitial sites and 40% at the substitutional sites at temperatures between 30 K and 296 K. The result for the KMnO₄ sample suggests a presence of an exotic chemical species corresponding to a higher valence state than Fe^{6 +}. Received: 1 May 2001 / Accepted: 4 December 2001     

A moiré system for producing numerical data of the profile of a turbine blade using a computer and video store

A new technique has been devised for coding and analysing moiré contours. It uses a video frame store in place of the more usual photographic reference grid, and a small microcomputer to automate fringe detection. The system is based on using a television camera to view a sample, the complete technique being developed primarily as an industrial tool for quality control, or as feedback sensor in flexible manufacturing.     

Relations of electronic energies and magnetic moments of tetra-3d metal (Mn, Fe, Co and Ni) nitrides calculated using a plane-wave basis method

Geometrical optimization of tetra-3d metal nitrides (Mn₄N, Fe₄N, Co₄N, and Ni₄N) has been performed and the relations of their energies (E) and their total magnetic moments (M) are obtained by plane-wave-basis density-functional calculations without any assumption of specific spin arrangement. The E vs. M relations obtained for Fe₄N and Mn₄N have a bimodal character. The ground state of Fe₄N is a high-spin state, which would correspond to the ferromagnetic character, while that of Mn₄N is a low-spin state, which would correspond to the observed ferrimagnetic character. Lattice constants and total magnetic moments of these tetra-3d metal nitrides are almost accurately predicted. From the spin-polarized densities of states curves, Co₄N would have the largest spin polarization ratio of 0.88, which suggests Co₄N can be a candidate material for ferromagnetic electrodes for spin-injection.     

The possibility of two compensation points in a ferrimagnetic mixed spin-1 and spin-3/2 Ising system using Bethe lattice approach

We give an exact formulation of a mixed spin-1 and spin-3/2 Ising model on the Bethe lattice, which shows ferrimagnetism and compensation points. The model incorporates antiferromagnetic nearest-neighbor interaction which is relevant to describe ferrimagnetism. The influence of two sublattice crystal fields, D_A and D_B, on compensation points is studied in detail. For certain crystal-field values, the single or double compensation temperature may occur in the present system.     

Densification and conductivity enhancement of Na4Zr2Si3O12-based solid electrolytes using TiO2 as a sintering aid

Densification of Na₄Zr₂Si₃O₁₂ (NZS) solid electrolytes was performed by dispersing TiO₂ (0.8–5.9 wt. %, corresponding to 5–30 mol %) in NZS powders prior to sintering at 1200°C. Increases in pellet density, from ca. 65 to 94% of the theoretical (X-ray density) value, and in electrical conductivity from 10⁻⁷ to 10⁻⁶ S/cm at 50°C were observed for small additions of TiO₂, which acts as a sintering aid. AC impedance spectroscopy reveals that the enhancement is not a bulk effect but instead is associated with a reduction in inter-granular constriction resistances within porous NZS ceramics. The presence of adsorbed water species in NZS powders prepared via a sol-gel route is found to have a dramatic effect on the conductivity enhancement.     

Pulverization of the flux line lattice, the phase coexistence and the spinodal temperature of the order—disorder transition in a weakly pinned crystal of Yb3Rh4Sn13

We have studied metastability effects pertaining to the peak effect (PE) in critical current density (J _c) via isofield scans in AC susceptibility measurements in a weakly pinned single crystal of Yb₃Rh₄Sn₁₃ (T _c(0) ≈ 7.6 K). The order-disorder transition in this specimen proceeds in a multi-step manner. The phase coexistence regime between the onset temperature of the PE and the spinodal temperature (where metastability effects cease) seems to comprise two parts, where ordered and disordered regions dominate the bulk behavior, respectively. The PE line in the vortex phase diagram is argued to terminate at the low field end at a critical point in the elastic (Bragg) glass phase.     

Polarised IR and Raman spectra of non‐centrosymmetric Na3Li(MoO4)2· 6H2O crystal—a new Raman laser material

Polarised IR and Raman spectra of Na₃Li(MoO₄)₂· 6H₂O single crystal were measured. Discussion of the results is based on the factor group approach for the trigonal R 3c(C_3v⁶) space group with Z = 2. The assignment of the observed bands was performed on the basis of their polarisation behaviour and literature data. The obtained results for the spontaneous Raman scattering were used in the analysis of the stimulated Raman spectra of the material studied—a new Raman laser crystal. The promoting modes of the stimulated effect were identified. Copyright © 2009 John Wiley & Sons, Ltd.     

Synthesis and Raman spectroscopic investigation of a new self‐assembly monolayer material 4‐[N‐phenyl‐N‐(3‐methylphenyl)‐amino]‐benzoic acid for organic light‐emitting devices

We have synthesized 4‐[N‐phenyl‐N‐(3‐methylphenyl)‐amino]‐benzoic acid (4‐[PBA]) and investigated its molecular vibrations by infrared and Raman spectroscopies as well as by calculations based on the density functional theory (DFT) approach. The Fourier transform (FT) Raman, dispersive Raman and FT‐IR spectra of 4‐[PBA] were recorded in the solid phase. We analyzed the optimized geometric structure and energies of 4‐[PBA] in the ground state. Stability of the molecule arising from hyperconjugative interactions and charge delocalization was studied using natural bond orbital analysis. The results show that change in electron density in the σ* and π* antibonding orbitals and E₂ energies confirm the occurrence of intramolecular charge transfer within the molecule. Theoretical calculations were performed at the DFT level using the Gaussian 09 program. Selected experimental bands were assigned and characterized on the basis of the scaled theoretical wavenumbers by their total energy distribution. The good agreement between the experimental and theoretical spectra allowed positive assignment of the observed vibrational absorption bands. Finally, the calculation results were applied to simulate the Raman and IR spectra of the title compound, which show agreement with the observed spectra. Copyright © 2011 John Wiley & Sons, Ltd.