Heat transfer improvement of antifreeze by changing it to hybrid nanofluid: effects of hybrid magnesium oxide–graphene oxide nanopowders

Journal of Thermal Analysis and Calorimetry - Hybrid nanofluids consisting of two or multiple nanoparticles have received much attention in recent decades. In this study, the rheological behavior...     

Effect of CH3NH3I/CH3NH3Br precursors on the structural and surface morphology properties of the electrodeposited methylammonium lead–mixed halide perovskite films

Journal of Solid State Electrochemistry - Organometallic halide perovskites have been arisen as a class of multi-purpose materials with exciting applications in optoelectronic devices such as solar...     

Reconciling structure prediction of alloyed,ultrathin nanowires with spectroscopy

A number of complementary, synergistic advances are reported herein. First, we describe the ‘first-time’ synthesis of ultrathin Ru₂Co₁ nanowires (NWs) possessing average diameters of 2.3 ± 0.5 nm using a modified surfactant-mediated protocol. Second, we utilize a combination of quantitative EDS, EDS mapping (along with accompanying line-scan profiles), and EXAFS spectroscopy results to probe the local atomic structure of not only novel Ru₂Co₁ NWs but also ‘control’ samples of analogous ultrathin Ru₁Pt₁, Au₁Ag₁, Pd₁Pt₁, and Pd₁Pt₉ NWs. We demonstrate that ultrathin NWs possess an atomic-level geometry that is fundamentally dependent upon their intrinsic chemical composition. In the case of the PdPt NW series, EDS mapping data are consistent with the formation of a homogeneous alloy, a finding further corroborated by EXAFS analysis. By contrast, EXAFS analysis results for both Ru₁Pt₁ and Ru₂Co₁ imply the generation of homophilic structures in which there is a strong tendency for the clustering of ‘like’ atoms; associated EDS results for Ru₁Pt₁ convey the same conclusion, namely the production of a heterogeneous structure. Conversely, EDS mapping data for Ru₂Co₁ suggests a uniform distribution of both elements. In the singular case of Au₁Ag₁, EDS mapping results are suggestive of a homogeneous alloy, whereas EXAFS analysis pointed to Ag segregation at the surface and an Au-rich core, within the context of a core–shell structure. These cumulative outcomes indicate that only a combined consideration of both EDS and EXAFS results can provide for an accurate representation of the local atomic structure of ultrathin NW motifs.

EDS and EXAFS spectroscopy are used as complementary techniques to investigate the local structure of bimetallic ultrathin nanowires. Results highlight the importance of using a combined approach to achieve an accurate understanding of these systems.     

Electrochemical synthesis of copper(II) oxide nanorods and their application in photocatalytic reactions

Journal of Solid State Electrochemistry - A new way of synthesizing nanoscale copper oxide particles is described in this work. Oxides of an intermediate metal, such as copper oxide, can be used as...     

Quality management in research: management process of the laboratories of Moroccan faculties of sciences and techniques

Accreditation and Quality Assurance - The implementation of a quality management system including management tools in the industrial sector has several advantages. In this perspective, can we use...     

Co-isolation of deoxynivalenol and zearalenone with sol–gel immunoaffinity columns for their determination in wheat and wheat products

The paper describes a sample clean-up method for the co-isolation of deoxynivalenol (DON) and zearalenone (ZON), two mycotoxins naturally co-occurring in wheat. The method is based on immunoaffinity columns prepared by co-immobilising anti-DON and anti-ZON antibodies in a porous sol–gel glass. The main task in developing the method consisted in finding a loading medium allowing retention of both analytes as well as a common elution medium for the dissociation of both antigen–antibody complexes formed. This can be achieved by co-extracting DON and ZON with ACN–water (60:40, v/v), reducing the acetonitril concentration to 2.5% before loading an aliquot of the diluted sample extract onto the DON/ZON column. The columns are washed with 5 ml of MeOH–water (10:90, v/v) before DON and ZON are co-eluted with 4 ml of ACN–water (50:50, v/v). Concentrations of DON and ZON are determined with HPLC-UV and HPLC-fluorescence detection, respectively. The sample clean-up method was shown to be applicable to wheat and wheat products, e.g., cornflakes, milk wheat mash and rusk. Spiking experiments (spike level 500 μg DON/kg and 50 μg ZON/kg) resulted in recovery rates from 82% to 111%.     

Mercury(II) complexes of stabilized phosphine-phosphonium ylide derived from bis(diphenylphosphino)methane: Synthesis, spectra and crystal structures

The reaction of a mixed phosphine-phosphonium ylide, PPh₂CH₂PPh₂C(H)C(O)Ph with mercury(II) halides in methanol under mild conditions yielded the P, C-chelated complexes, [HgX₂(PPh₂CH₂PPh₂C(H)C(O)Ph)] where X = Cl (2), Br (3), I (4). Single crystal X-ray diffraction studies reveal the presence of mononuclear complexes containing Hg atom in a distorted tetrahedral environment and long Hg-C_ylide bond. The five-membered chelate rings in the two independent molecules present in the asymmetric unit of 4 adopt ‘envelope’ and ‘twist’ conformations. Spectroscopic studies also indicate the weaker Hg-C bonding. Additionally, the molecular structure of the free ylide (1) is also discussed.