3,656 research outputs found
Space Charge Modelling in Solid Dielectrics under High Electric Field Based on Double Charge Injection Model
Present study aims to develop a clear insight on factors that influence space charge dynamics in solid dielectrics through a numerical simulation. The model used for the simulation is proposed by Alison and Hill [1] which describes charge dynamics as a result of bipolar transport with single level trapping. In this model, a constant mobility and no detrapping have been assumed. The simulation results show that carrier mobility, trapping coefficient and Schottky barrier have a significant effect on the space charge dynamics. Many features of space charge profiles observed by experiments have been revealed in despite of over simplistic model. More importantly, the simulation allows us to study the role of each individual parameter in the formation of space charge in solid dielectrics, so that the experimental results can be better understood
Algebraic Rainich conditions for the tensor V
Algebraic conditions on the Ricci tensor in the Rainich-Misner-Wheeler
unified field theory are known as the Rainich conditions. Penrose and more
recently Bergqvist and Lankinen made an analogy from the Ricci tensor to the
Bel-Robinson tensor , a certain fourth rank tensor
quadratic in the Weyl curvature, which also satisfies algebraic Rainich-like
conditions. However, we found that not only does the tensor
fulfill these conditions, but so also does our recently
proposed tensor , which has many of the desirable
properties of . For the quasilocal small sphere limit
restriction, we found that there are only two fourth rank tensors
and which form a basis for good
energy expressions. Both of them have the completely trace free and causal
properties, these two form necessary and sufficient conditions. Surprisingly
either completely traceless or causal is enough to fulfill the algebraic
Rainich conditions. Furthermore, relaxing the quasilocal restriction and
considering the general fourth rank tensor, we found two remarkable results:
(i) without any symmetry requirement, the algebraic Rainich conditions only
require totally trace free; (ii) with a symmetry requirement, we recovered the
same result as in the quasilocal small sphere limit.Comment: 17 page
Probability over Płonka sums of Boolean algebras: States, metrics and topology
The paper introduces the notion of state for involutive bisemilattices, a variety which plays the role of algebraic counterpart of weak Kleene logics and whose elements are represented as Płonka sums of Boolean algebras. We investigate the relations between states over an involutive bisemilattice and probability measures over the (Boolean) algebras in the Płonka sum representation and, the direct limit of these algebras. Moreover, we study the metric completion of involutive bisemilattices, as pseudometric spaces, and the topology induced by the pseudometric
Limit Analysis of Strain Softening Frames Allowing for Geometric Nonlinearity
This paper extends classical limit analysis to account for strain softening and 2nd-order geometric nonlinearity simultaneously. The formulation is an instance of the challenging class of socalled (nonconvex) mathematical programs with equilibrium constraints (MPECs). A penalty algorithm is proposed to solve the MPEC. A practical frame example is provided to illustrate the approach
Balanced metrics on homogeneous vector bundles
Let be a holomorphic vector bundle over a compact Kaehler
manifold and let be its
decomposition into irreducible factors. Suppose that each admits a
-balanced metric in Donaldson-Wang terminology. In this paper we prove
that admits a unique -balanced metric if and only if
for all , where denotes
the rank of and . We apply our result to the case
of homogeneous vector bundles over a rational homogeneous variety
and we show the existence and rigidity of balanced Kaehler embedding from into Grassmannians.Comment: 5 page
Balanced metrics on Cartan and Cartan-Hartogs domains
This paper consists of two results dealing with balanced metrics (in S.
Donaldson terminology) on nonconpact complex manifolds. In the first one we
describe all balanced metrics on Cartan domains. In the second one we show that
the only Cartan-Hartogs domain which admits a balanced metric is the complex
hyperbolic space. By combining these results with those obtained in [13]
(Kaehler-Einstein submanifolds of the infinite dimensional projective space, to
appear in Mathematische Annalen) we also provide the first example of complete,
Kaehler-Einstein and projectively induced metric g such that is not
balanced for all .Comment: 11 page
WS15.2 Derivation of normal and cystic fibrosis human induced pluripotent stem cells (iPSCs) from airway epithelium
Gravitational energy from a combination of a tetrad expression and Einstein's pseudotensor
The energy-momentum for a gravitating system can be considered by the tetard
teleparalle gauge current in orthonormal frames. Whereas the Einstein
pseudotensor used holonomic frames. Tetrad expression itself gives a better
result for gravitational energy than Einstein's. Inspired by an idea of Deser,
we found a gravitational energy expression which enjoys the positive energy
property by combining the tetrad expression and the Einstein pseudotensor,
i.e., the connection coefficient has a form appropriate to a suitable
intermediate between orthonormal and holonomic frames.Comment: 5 page
- …