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Continuum theory of granular materials
Published in M. Oda, K. Iwashita, Mechanics of Granular Materials, 2020
Spencer’s theory was extended for strain softening behavior with dilatancy by Mehrabadi & Cowin (1978) where the dilatancy was represented by a single material parameter ν, the angle of dilatancy, which may not be constant. Furthermore Mehrabadi & Cowin (1980) compared their double sliding model with a yield-vertex model of Rudnicki & Rice (1975) to show that an extended yield-vertex model includes the double sliding model as a special case. They express that it is interesting that a post-failure model such as the double sliding model coincides with a pre-failure (hardening) model like the yield-vertex model. In other words, they show that the double shearing model may be used as a hardening pre-failure model for geomaterials.
Subneuronal Processing of Information by Solitary Waves and Stochastic Processes
Published in Sergey Edward Lyshevski, Nano and Molecular Electronics Handbook, 2018
Danko D. Georgiev, James F. Glazebrook
The procedure involving action–angle coordinates and the functional integration method amounts to introducing quantum parameters, thus converting the SG equation to the quantum sine–Gordon (QSG) equation in (1 + 1)–dimensions where the latter can be described as a Bose system. In [108], the associated kinks and antikinks are postulated as “classical fermions.” In strictly mathematical terms, the Bethe ansatz, in relationship to the QSG, provides (bijective) correspondences with certain classes of solvable lattice models such as the quantum spin12 − XYZ model, Baxter’s 8–vertex model of statistical mechanics (which contains the two-dimensional Ising model [9]), together with the quantum massive Thirring model (see [16,77]). In a broad sense, the quasi–relativistic effects and supersonic propagation of solitons in relationship to the SG model, are discussed in [82], demonstrating analogies with acoustical and optical systems, a feature of our discussion that will be explored at a later stage.
Exactly Solved Frustrated Models in Two Dimensions
Published in Hung T. Diep, Physics of Magnetic Thin Films, 2021
Any 2D Ising model with non-crossing interactions can be exactly solved. To avoid the calculation of the partition function one can transform the model into a 16-vertex model or a 32-vertex model. The resulting vertex model is exactly solvable. We have applied this method to search for the exact solution of several Ising frustrated 2D models with non-crossing interactions shown in Figs. 7.5–7.7.
Unlocking the potential of 2,1,3-benzoxadiazole-based luminescent liquid crystals
Published in Liquid Crystals, 2023
Fabrícia Nunes da Silva, Eliane Oliveira Silva, Gerson dos Santos, Bruna B. Postacchini, Thiago Cazati, Ivan H. Bechtold, André Alexandre Vieira
Infrared spectra were recorded on a Bruker VERTEX, model 70/70 V, spectrometer in KBr discs or films. 1H NMR spectra were obtained with a Varian Mercury Plus 400-MHz instrument using tetramethylsilane (TMS) as the internal standard. 13C NMR spectra were recorded on a Varian Mercury Plus 100-MHz spectrometer. The melting points and the mesomorphic textures were determined using an Olympus B×50 microscope equipped with a Mettler Toledo FP-82 hot stage and a PM-30 exposure control unit. The chromatograms and low-resolution mass spectra were obtained on a Shimadzu GCMS-QP5050A instrument equipped with a DB5-MS ((5%-phenyl)-dimethylpolysiloxane) capillary column (25 m × 250 µm × 0.25 µm) using an electron ionisation voltage of 70 eV. The oven parameters used in the method were 80°C for 6 min, increasing at 15°C/min to 280°C and remaining at this temperature for 4 min, giving a run time of 23.333 min with an initial delay of 4 min. The gas flow was He2 at 0.6 mL/min, with pressure S3 of 2.3301 psi.
Magnetic nanomodified activated carbon: characterization and use for organic acids sorption in aqueous medium
Published in Chemical Engineering Communications, 2021
Júlia Adorno Barbosa, Geórgia Labuto, Elma Neide Vasconcelos Martins Carrilho
The sorbents were characterized by X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy. The X-ray diffraction analyses (Rigaku MiniFlex 600, Japan) were performed in order to identify the crystalline phases present in the modified material. The procedure applied CuKα tube (λ = 1.5406 Å), operating at 40 kV and 30 mA. Data were acquired in the range of 2° − 70° at a 0.02° per second rate. Data were analyzed based on the reference values from JCPDS (Joint Committee on Powder Diffraction Standards). Scanning Electron Microscopy (SEM) was performed (Electroscan/Philips ESEM 2020, USA) at 30 kV with a tungsten filament, coupled to an Energy-Dispersive Spectrometer (EDAX EDS, Rigaku, Japan). Fourier Transform Infrared Spectroscopy (FTIR, Bruker, Vertex Model, USA) analysis allowed the identification of functional groups in the materials. The equipment operated with 32 scanners in the range of 4000 to 400 cm−1, with a resolution of 4 cm−1, and 32 scans per sample, using pellets prepared with approximately 1 mg of each material (AC, MNP, and AC-MNP before and after sorption of the OA) and 100 mg of KBr.
Coarse-grained modeling of cell division in 3D: influence of density, medium viscosity, and inter-membrane friction on cell growth and nearest neighbor distribution
Published in Soft Materials, 2020
Pranav Madhikar, Jan Åström, Jan Westerholm, Björn Baumeier, Mikko Karttunen
Sandersius et al. compiled a number of experimental measurements of nearest neighbors () in epithelial systems (Fig. 4). Note that the proportion of cells with each value of is basically the same between species. This suggests that even if epithelial tissue is taken from biologically different species, the cells within the tissues may be mechanically quite similar. Sandersius et al. showed that this may be the case by comparing to the results of another computational study with the vertex model of Gibson et al.[63] Here, we do the same with CellSim3D and the number of nearest neighbors measured from simulation trajectories serves as:[1] another proxy measurement for crowding,[2] more validation for the CellSim3D model. Combined with the measurement of , it would be more evidence of mechanics affecting growth. This simultaneous measurement of tissue structure and density, and their correlation(s) to growth is (are) only possible with a more faithful representation of cell membranes, cell growth, and cell division such as in the CellSim3D model.