Impact of Thermal Oxidation on Morphological,Structural and Magnetic Properties of Fe-Ni Wire-Like Nanochains

Metallurgical and Materials Transactions A - This work presents the evolution of morphological, structural and magnetic properties of amorphous Fe-Ni wire-like nanochains caused by thermal...     

Fundamental understanding of high-capacity lithium-excess cathodes with disordered rock salt structure

As a new class of lithium rich cathodes,disordered rock-salt cathodes have been of primary interest,because of their ability to deliver a promisingly high capacity up to 300 mA h/g.Nevertheless,some fundamental issues are yet to be fully understood and a comprehensive mastering of their solid-state chemistry,kinetics and thermal stability is required.Here,we select a high capacity cation-disordered positive electrode-Li1.2Ni0.4Nb0.4O2 as a model compound to study intrinsic reaction mechanism,including charge compensation mechanism,kinetics,thermal stability,and structural evolution.By combining soft and hard X-ray absorption spectroscopy (XAS),X-ray photoelectron spectroscopy (XPS) with operando and exsitu differential scanning calorimetry (DSC),galvanostatic intermittent titration technique (GITr),cyclic voltammetry (CV),and X-ray diffraction (XRD),we present holistic information on disordered rock-salt cathode.This work provides beneficial insights into designing and tailoring new positive electrodes with disordered rock-salt structure.     

Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale

Magnetic Resonance Materials in Physics, Biology and Medicine - An initiative to design and build magnetic resonance imaging (MRI) and spectroscopy (MRS) instruments at 14 T and beyond to...     

In-house validation of an ELISA method for screening of semicarbazide in eggs

An enzyme-linked immunosorbent assay (ELISA) method is described for the semi-quantitative determination of semicarbazide (SEM), the marker residue for the banned nitrofuran drug, nitrofurazone, in chicken eggs. The sample homogenate is subjected to acid hydrolysis and derivatisation with o-nitrobenzaldehyde, followed by ethyl acetate/hexane extraction and detection by ELISA. The ELISA procedure has been validated using 0.3, 1.0 and 3 µg kg^?1 of SEM in fortified samples. Detection capability (CC_ß) was based on the acceptance of 5% false compliant results for a given concentration level according to Commission Decision 2002/657/EC and was determined to be 0.3 µg kg^?1 with a respective limit of detection of 0.13 µg kg^?1. A validated LC–MS/MS method was used for the analysis of incurred egg samples and the results compared with ELISA. A good correlation between the results obtained from ELISA and LC–MS/MS within the concentration range 0.12–20.3 µg kg^?1 was observed in samples collected from chickens fed with a medicated ration of nitrofurazone (r?=?0.992, n?=?14). Validated ELISA enabled reliable monitoring of SEM levels in eggs collected from incurred chickens over a 90-day period.     

Assessment of electromechanical properties of screen printed polymer nanopastes

Printed electronics has provided different printing techniques as environmentally friendly and cost-effective manufacturing methods of electronic components. The printed items can be produced on low cost, different types of flexible substrates, even when their surface is corrugated. This opens a new application range of printed electronics and makes them competitive with traditionally manufactured electronics. However, it is necessary to investigate new materials to continue the rapid progress in printed electronics. In our study, the electromechanical properties of polymer nanopastes consisted of carbon nanotubes and graphite platelet nanofibers mixed with a conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were investigated. Their microstructure and the layer morphology were observed using a scanning electron microscope and an optical microscope. The thickness and average roughness of the layers printed on the foil and paper were determined with a contact profilometer. The mechanical durability of the screen printed layers was verified in a cyclic bending test. The highest mechanical durability was exhibited by the polymer pastes containing carbon nanotubes.     

Short- and mid-term adsorption behaviour of Quillaja Bark Saponin and its mixtures with lysozyme

The short- and mid-term adsorption kinetics of Quillaja Bark Saponin (QBS) biosurfactant at water–air interface was studied using a maximum bubble pressure and drop shape analysis techniques, respectively. The low values of diffusion coefficients at initial and close-to equilibrium stages of adsorption suggest that adsorption of QBS is mixed-diffusion barrier controlled. Increasing the ionic strength or decreasing pH helps to screen the negative charge of the glucuronic acid moiety of QBS and results in enhanced surface activity of QBS. The surface tension isotherms at pH 2.6 (HCl solution, unbuffered), 6.2 (pure water, unbuffered) and 7.4 (phosphate buffer, I = 0.1 M) were fitted using the Frumkin model. The influence of a model protein (hen egg lysozyme, LYS) on adsorption of QBS on short- and mid-term timescales was studied at fixed LYS concentration of 10⁻⁵ M and varying QBS concentration. The synergistic effects in QBS adsorption were observed due to formation of LYS–QBS complex, whose surface activity increases at low QBS concentrations. The complex may be formed either in bulk solution, prior to adsorption, or directly at the surface, through co-adsorption of the slower diffusing component on the pre-adsorbed layer of the other component. At high concentrations of QBS, the latter dominates the adsorption process, depleting the surface from LYS and LYS–QBS complex. The synergistic effects found in adsorption kinetics of LYS–QBS mixtures were assessed in foamability tests using a modified Bikerman method.     

Salt Effect on the Solution Properties of Cationic Gemini/Conventional Surfactants in the Presence of the Nonionic Polymer Hydroxypropylmethyl Cellulose

In this article, we report the salt effect on interaction of a water-soluble polymer hydroxypropylmethyl cellulose (HPMC) with the cationic Gemini surfactant (ethane-1, 2-diyl bis(N,N-dimethyl-N-hexadecylammoniumacetoxy) dichloride, 16-E2-16), and also its monomeric counterpart cetyltrimethylammonium chloride (CTAC) using the tensiometric method. Surface tension of the amphiphiles diminished in the presence of the polymer as well as salts; eventually, the polymer gets saturated with the surfactant and there is no further change of surface tension of the solution. Interaction between the polymer and surfactant starts at the critical aggregation concentration (CAC) that is stronger for 16-E2-16 than CTAC. CAC and critical micelle concentration (CMC) values of the surfactant-polymer binary mixtures at various concentrations of the polymer were determined. CAC as well as CMC of 16-E2-16 are considerably lower than CTAC. The inorganic salts (KCl and KBr) have a considerable influence on the polymer–surfactant interaction.