Effects of gas and soot radiation on soot formation in counterflow ethylene diffusion flames

Numerical study of soot formation in counterflow ethylene diffusion flames at atmospheric pressure was conducted using detailed chemistry and complex thermal and transport properties. Soot kinetics was modelled using a semi-empirical two-equation model. Radiation heat transfer was calculated using the discrete-ordinates method coupled with an accurate band model. The calculated soot volume fractions are in reasonably good agreement with the experimental results in the literature. The individual effects of gas and soot radiation on soot formation were also investigated.     

Crystal chemistry and electronic structure of the metallic lithium ion conductor, LiNiN

The layered ternary nitride LiNiN shows an interesting combination of fast Li+ ion diffusion and metallic behavior, properties which suggest potential applications as an electrode material in lithium ion batteries. A detailed investigation of the structure and properties of LiNiN using powder neutron diffraction, ab initio calculations, SQUID magnetometry, and solid-state NMR is described. Variable-temperature neutron diffraction demonstrates that LiNiN forms a variant of the parent Li3N structure in which Li+ ion vacancies are ordered within the [LiN] planes and with Ni exclusively occupying interlayer positions (at 280 K: hexagonal space group Pm2, a = 3.74304(5) A, c = 3.52542(6) A, Z = 1). Calculations suggest that LiNiN is a one-dimensional metal, as a result of the mixed pi- and sigma-bonding interactions between Ni and N along the c-axis. Solid-state 7Li NMR spectra are consistent with both fast Li+ motion and metallic behavior.     

Wavelet bases on a manifold

Using the decomposition method, we present in this paper constructions of multiresolution analyses on a compact Riemannian manifold M of dimension n(n∈N). These analyses are generated by a finite number of basic functions and are adapted to the study of the Sobolev spaces H¹(M) and .     

Theoretical third-order hyperpolarizability of paratellurite from the finite field perturbation method

Density functional theory was used to estimate the third-order hypersusceptibility chi (3) of the alpha-TeO2 paratellurite (as a model structure for TeO2 glass) and the same value for alpha-SiO2 cristobalite (as a model structure for glassy silica). The attempt was made to gain a physical insight into the nature of the extraordinarily high hypersusceptibility of TeO2 glass. A finite field perturbation method implemented in the CRYSTAL code with the "sawtooth" approach was employed. The chi (3) values calculated for alpha-TeO2 were found to be of the same order as that measured for TeO2 glass and much higher than the values computed for alpha-SiO2 which, in turn, were close to that of glassy silica.     

Characterization of Primary Action Mode of Eight Essential Oils and Evaluation of Their Antibacterial Effect against Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli Inoculated in Turkey Meat

The current study aims to evaluate the antimicrobial activity of eight essential oils (EOs) against multidrug-resistant Escherichia coli strains, producing extended-spectrum β-lactamase (ESBL) enzymes and isolated from foods. Disc-diffusion assay showed that the inhibition diameters generated by EOs varied significantly among the tested EOs and strains. In fact, EOs extracted from Thymus capitaus, Eucalyptus camaldulensis, Trachyspermum ammi and Mentha pulegium exerted an important antimicrobial effect against tested strains, with the diameters of inhibition zones varied between 20 and 27 mm. Moreover, minimal inhibition and bactericidal concentration (MIC and MBC) values demonstrated that T. capitatus EOs generate the most important inhibitory effect against E. coli strains, with MIC values ranging from 0.02 to 0.78%. Concerning the mode of action of T. capitatus EO, the obtained data showed that treatment with this EO at its MIC reduced the viability of E. coli strains, their tolerance to NaCl and promoted the loss of 260-nm-absorbing material. In addition, in the presence of T. capitatus EO, cells became disproportionately sensitive to subsequent autolysis. Moreover, the inhibitory effect of T. capitatus was evaluated against two E. coli strains, experimentally inoculated (10⁵ CFU/g) in minced turkey meat, in the presence of two different concentrations of EO (MIC and 2 × MIC), and stored for 15 days. In both samples, EO exerted a bacteriostatic effect in the presence of concentrations equal to MIC. Interestingly, at 2 × CMI concentration, the bactericidal activity was pronounced after 15 days of storage. Our results highlighted that the use of essential oils, specially of T. capitatus, to inhibit or prevent the growth of extended-spectrum β-lactamase (ESBL)-producing E. coli in food, may be a promising alternative to chemicals.     

Multiplicity Results for the Biharmonic Equation with Singular Nonlinearity of Super Exponential Growth in ℝ4

Mathematical Notes - We consider the following elliptic problem of exponential-type growth posed in an open bounded domain with smooth boundary B1 (0) ? ?4:...     

Neuropeptidomics: Comparison of parallel reaction monitoring and data‐independent acquisition for the analysis of neuropeptides using high‐resolution mass spectrometry

Targeted peptide quantitation by mass spectrometry is a rapidly emerging field. Traditionally it relied on the development and validation of multiple reaction monitoring assays that could comply with a high level of sensitivity, specificity, accuracy and reproducibility in complex biological samples. However, with the introduction of high‐resolution mass spectrometers, other acquisition modes could provide more comprehensive datasets for identification and quantification but also for in‐depth data mining. The objective of this study was to evaluate two analytical approaches, parallel‐reaction monitoring (PRM) and data‐independent analysis (DIA) using a hybrid Quadrupole–Orbitrap mass spectrometer for the quantification of neuropeptides in animal spinal cord tissues. Mouse spinal cord tissues were harvested, homogenized and neuropeptides extracted using a C₁₈ solid‐phase extraction protocol. Chromatography was achieved using a Thermo Biobasic C₈ 100 × 1 mm (5 μm) column. The initial mobile phase conditions consisted of acetonitrile and water (both containing 0.1% of formic acid) at a ratio of 5:95. An 11 min linear gradient was applied up to a ratio of 50:50 and maintained for 3 min. The flow rate was fixed at 75 μL/min and 2 μL of sample was injected. Mass spectrometry analyses were performed using a Thermo Q Exactive Plus MS using PRM and DIA approaches. Quantitative data using an isotopic dilution and a label‐free strategy were obtained for both methods and statistically compared. Using both approaches, we were able to clearly detect endogenous neuropeptides. However, with DIA, mass spectra alone could not distinguish Leu‐Enk and Met‐Enk. We used a Bland–Altman plot (Difference plot) to analyze the agreement between both approaches and no systematic bias was observed. Further statistical analyses, including variance analysis, showed more variability in DIA compared with PRM mode. Further analyses were performed using a label‐free approach and confirmed an increase of the variance using a DIA approach.     

Soot volume fractions and primary particle size estimate by means of the simultaneous two-color-time-resolved and 2D laser-induced incandescence

An original approach of laser-induced incandescence consisting in the simultaneous recording of the two-color-time-resolved and 2D LII signal is described in this paper. The application of this approach in an atmospheric pressure diffusion flame fueled with isooctane as well as inside the combustion chamber of a diesel engine is presented. Soot volume fraction and primary particle diameters are calculated, and the results are discussed. The mean diameter estimated by fitting the LII modeled curve on the experimental one is compared with the results obtained through soot sampling and microscope analyzing. The influence of the thermal accommodation coefficient and soot refractive index function is also discussed. PACS 47.80.-v; 42.40.Pa; 42.62.Eh; 47.54.De