65 research outputs found
A coarse-grained multiscale model to simulate morphological changes of food-plant tissues undergoing drying
Numerical modelling has emerged as a powerful and effective tool to study various dynamic behaviours of biological matter. Such numerical modelling tools have contributed to the optimisations of food drying parameters leading to higher quality end-products in the field of food engineering. In this context, on of the most recent developments is the mesh-free based numerical models, which have demonstrated enhanced capabilities to model cellular deformations during drying, providing many benefits compared to conventional grid-based modelling approaches. However, the potential extension of this method for simulating bulk level tissues has been a challenge due to the increased requirement for higher computaional time and resources. As a solution for this, by incorporating meshfree features, a novel coarse-grained multiscale numerical model is proposed in this work to predict bulk level (macroscale) deformations of food plant tissues during drying
An introduction to programming Physics-Informed Neural Network-based computational solid mechanics
Physics-informed neural network (PINN) has recently gained increasing
interest in computational mechanics. In this work, we present a detailed
introduction to programming PINN-based computational solid mechanics. Besides,
two prevailingly used physics-informed loss functions for PINN-based
computational solid mechanics are summarised. Moreover, numerical examples
ranging from 1D to 3D solid problems are presented to show the performance of
PINN-based computational solid mechanics. The programs are built via Python
coding language and TensorFlow library with step-by-step explanations. It is
worth highlighting that PINN-based computational mechanics is easy to implement
and can be extended for more challenging applications. This work aims to help
the researchers who are interested in the PINN-based solid mechanics solver to
have a clear insight into this emerging area. The programs for all the
numerical examples presented in this work are available on
https://github.com/JinshuaiBai/PINN_Comp_Mech.Comment: 32 pages, 20 figures are include in this manuscrip
Magnetoresistivity and Complete in
Detailed magneto-transport data on dense wires of are reported for
applied magnetic fields up to 18 T. The temperature and field dependencies of
the electrical resistivity are consistent with behaving like a simple
metal and following a generalized form of Kohler's rule. In addition, given the
generally high values and narrow resistive transition widths associated
with synthesized in this manner, combined with applied magnetic fields
of up to 18 T, an accurate and complete curve could be determined.
This curve agrees well with curves determined from lower field measurements on
sintered pellets and wires of . is linear in over a wide
range of temperature (7 K 32 K) and has an upward curvature for
close to . These features are similar to other high , clean limit,
boron-bearing intermetallics: and .Comment: minor changes in styl
A 3-D meshfree numerical model to analyze cellular scale shrinkage of different categories of fruits and vegetables during drying
In order to optimize food drying operations, a good understanding on the related transport phenomena in food cellular structure is necessary. With that intention, a three-dimensional (3-D) numerical model was developed to better investigate the morphological changes and
related solid and fluid dynamics of single parenchyma cells of apple, carrot and grape during drying. This numerical model was developed by coupling a meshfree particle based method:Smoothed Particle Hydrodynamics (SPH) with a Discrete Element Method (DEM). Compared to conventional grid-based numerical modelling techniques such as Finite Element Methods (FEM) and Finite Difference Methods (FDM), the proposed model can better simulate deformations and cellular shrinkage within a wide range of moisture content reduction. The model consists of two main components: cell fluid and cell wall. The cell fluid model is based
on SPH and represents the cell protoplasm as a homogeneous Newtonian liquid. The cell wall model is based on a DEM and approximates the cell wall to an incompressible Neo-Hookean
solid material. A series of simulations were conducted to mimic the gradual shrinkage during drying as a function of moisture content
Superconducting gap anisotropy of LuNi2B2C thin films from microwave surface impedance measurements
Surface impedance measurements of LuNi2B2C superconducting thin films as a
function of temperature have been performed down to 1.5 K and at 20 GHz using a
dielectric resonator technique. The magnetic penetration depth closely
reproduces the standard B.C.S. result, but with a reduced value of the energy
gap at low temperature. These data provide evidence for an anisotropic s-wave
character of the order parameter symmetry in LuNi2B2C. From the evaluation of
the real part of complex conductivity, we have observed constructive (type II)
coherence effects in the electromagnetic absorption below Tc.Comment: 15 pages, 4 figure
Thermopower and thermal conductivity of superconducting perovskite
The thermopower and thermal conductivity of superconducting perovskite
( 8 K) have been studied. The thermopower is negative
from room temperature to 10 K. Combining with the negative Hall coefficient
reported previously, the negative thermopower definetly indicates that the
carrier in is electron-type. The nonlinear temperature dependence of
thermopower below 150 K is explained by the electron-phonon interaction
renormalization effects. The thermal conductivity is of the order for
intermetallics, larger than that of borocarbides and smaller than . In
the normal state, the electronic contribution to the total thermal conductivity
is slightly larger than the lattice contribution. The transverse
magnetoresistance of is also measured. It is found that the classical
Kohler's rule is valid above 50 K. An electronic crossover occures at , resulting in the abnormal behavior of resistivity, thermopower, and
magnetoresistance below 50 K.Comment: Revised on 12 September 2001, Phys. Rev. B in pres
Determination of superconducting anisotropy from magnetization data on random powders as applied to LuNiBC, YNiBC and MgB
The recently discovered intermetallic superconductor MgB2 appears to have a
highly anisotopic upper critical field with Hc2(max)/Hc2(min} = \gamma > 5. In
order to determine the temperature dependence of both Hc2(max) and Hc2(min) we
propose a method of extracting the superconducting anisotropy from the
magnetization M(H,T) of randomly oriented powder samples. The method is based
on two features in dM/dT the onset of diamagnetism at Tc(max), that is commonly
associated with Hc2, and a kink in dM/dT at a lower temperature Tc(min).
Results for LuNi2B2C and YNi2B2C powders are in agreement with anisotropic Hc2
obtained from magneto-transport measurements on single crystals. Using this
method on four different types of MgB2 powder samples we are able to determine
Hc2(max)(T) and Hc2(min)(T) with \gamma \approx 6
Upper critical field pecularities of superconducting YNi2B2C and LuNi2B2C
We present new upper critical field Hc2(T) data in a broad temperature region
from 0.3K to Tc for LuNi2B2C and YNi2B2C single crystals with well
characterized low impurity scattering rates. The absolute values for all T, in
particular Hc2(0), and the sizeable positive curvature (PC) of Hc2(T) at high
and intermediate T are explained quantitatively within an effective two-band
model. The failure of the isotropic single band approach is discussed in
detail. Supported by de Haas van Alphen data, the superconductivity reveals
direct insight into details of the electronic structure. The observed maximal
PC near Tc gives strong evidence for clean limit type II superconductors.Comment: 4 pages, 2 figures, Phys. Rev. Lett. accepte
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