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Biorefinery lignin was carbonized under a carbon dioxide atmosphere at various temperatures viz., 500 °C, 600 °C, 700 °C, and 800 °C, separately. The results indicated that with increasing temperature, the mass yield decreased from 49.2% to 39.8%. Carbonization at a high temperature resulted in an increment of carbon (C) content and decreased both the hydrogen (H) and oxygen (O) contents. With the increase of carbonization severity, the ratios of O/C and H/C decreased mainly due to the demethanation, dehydration, and decarboxylation reactions. The carbonization resulted in the transformation of aromatic rings as well as the rearrangement of the aromatic polymers, and the enhancement of the thermal stability of the charcoal formed. [ABSTRACT FROM AUTHOR]

Let (G) and e(G) denote the domination number and exponential domination number of graph G, respectively. Henning et al., in [Hered-itary equality of domination and exponential domination, Discuss. Math. Graph Theory 38 (2018) 275-285] gave a conjecture: There is a finite set F of graphs such that a graph G satisfies (H) = e(H) for every induced subgraph H of G if and only if G is F-free. In this paper, we study the conjecture for subcubic graphs. We characterize the class F by minimal forbidden induced subgraphs and prove that the conjecture holds for subcubic graphs. [ABSTRACT FROM AUTHOR]

In this paper, the improved Jacobian elliptic function expansion approach is extended and applied to constructing discrete solutions of the semi-discrete coupled modified Korteweg de Vries (mKdV) equations with the aid of the symbolic computation system Maple. Some new discrete Jacobian doubly periodic solutions are obtained. When the modulus m → 1 these doubly periodic solutions degenerate into the corresponding solitary wave solutions, including kink-type, bell-type and other types of excitations. [ABSTRACT FROM AUTHOR]

The article offers information on a study conducted by the authors on transfer of angular momentum in optical near-fields of optical antennas. Topics discussed include deviation of geometrical antenna from photoemission yield, confinement of near-field to antenna arms with reduced polarization, increased circular polarization in the center of antenna, and momentum transfer by transfer of spin polarized electrons.

Using a combination of photoemission electron microscopy and numerical simulations, we investigated the angular moment transfer in strongly enhanced optical near-fields of artificially fabricated optical antennas. The polarization dependence of the optical near-field enhancement has been measured in a maximum symmetric geometry, i.e., excitation by a normal incident planar wave. Finite-difference time-domain simulations for the realistic antenna geometries as determined by high-resolution electron microscopy reveal a very good agreement with experimental data. The agreement confirms that the geometrical asymmetries and inhomogeneities due to the nanoscale fabrication process preserve the circular polarization in the gap regions with strong near-field enhancement. [ABSTRACT FROM AUTHOR]

We experimentally demonstrate synthesis and in situ analysis of multimode plasmonic excitations in two-wire transmission lines supporting a symmetric and an antisymmetric eigenmode. To this end we irradiate an incoupling antenna with a diffraction-limited excitation spot exploiting a polarization- and position-dependent excitation efficiency. Modal analysis is performed by recording the far-field emission of two mode-specific spatially separated emission spots at the far end of the transmission line. To illustrate the power of the approach we selectively determine the group velocities of symmetric and antisymmetric contributions of a multimode ultrafast plasmon pulse. [ABSTRACT FROM AUTHOR]