992 research outputs found
Tax Planning in Business Purchase Agreements, with Sample Clauses
The success or failure of the small- or medium-sized business is dependent primarily upon the ability of its key-men, who are generally the owners of the business. The death or retirement of one of these men, therefore, if not provided for, can cause havoc with the business to the detriment of the remaining shareholders or partners. This Article will consider the tax problems raised by the death of a stockholder and the death or retirement of a partner and the most practical and beneficial methods of anticipating and meeting those problems
Characteristics of ferroelectric-ferroelastic domains in N{\'e}el-type skyrmion host GaVS
GaVS is a multiferroic semiconductor hosting N{\'e}el-type magnetic
skyrmions dressed with electric polarization. At T = 42K, the compound
undergoes a structural phase transition of weakly first-order, from a
non-centrosymmetric cubic phase at high temperatures to a polar rhombohedral
structure at low temperatures. Below T, ferroelectric domains are formed
with the electric polarization pointing along any of the four axes. Although in this material the size and the shape of the
ferroelectric-ferroelastic domains may act as important limiting factors in the
formation of the N{\'e}el-type skyrmion lattice emerging below T=13\:K, the
characteristics of polar domains in GaVS have not been studied yet.
Here, we report on the inspection of the local-scale ferroelectric domain
distribution in rhombohedral GaVS using low-temperature piezoresponse
force microscopy. We observed mechanically and electrically compatible lamellar
domain patterns, where the lamellae are aligned parallel to the (100)-type
planes with a typical spacing between 100 nm-1.2 m. We expect that the
control of ferroelectric domain size in polar skyrmion hosts can be exploited
for the spatial confinement and manupulation of N{\'e}el-type skyrmions
Relaxation at late stages in an entropy barrier model for glassy systems
The ground state dynamics of an entropy barrier model proposed recently for
describing relaxation of glassy systems is considered. At stages of evolution
the dynamics can be described by a simple variant of the Ehrenfest urn model.
Analytical expression for the relaxation times from an arbitrary state to the
ground state is derived. Upper and lower bounds for the relaxation times as a
function of system size are obtained.Comment: 9 pages no figures. to appear in J.Phys. A: Math. and Ge
Molecular diffusion on a time scale between nano- and milliseconds probed by field-cycling NMR relaxometry of intermolecular dipolar interactions: Application to polymer melts
A formalism is presented permitting the evaluation of the relative mean-squared displacement of molecules from the intermolecular contribution to spin-lattice relaxation dispersion of dipolar coupled spins. The only condition for the applicability is the subdiffusive power law character of the time dependence of the mean-squared displacement as it is typical for the chain mode regime in polymer liquids. Using field-cycling NMR relaxometry, an effective diffusion time range from nano- to almost milliseconds can be probed. The intermolecular spin-lattice relaxation contribution can be determined with the aid of isotopic dilution, that is, mixtures of undeuterated and deuterated molecules. Experiments have been performed with melts of polyethyleneoxide and polybutadiene. The mean-squared segment displacements have been evaluated as a function of time over five decades. The data can be described by a power law. The extrapolation to the much longer time scale of ordinary field-gradient NMR diffusometry gives good coincidence with literature data. The total time range thus covers nine decades. © 2007 American Institute of Physics
Deuteron and proton spin-lattice relaxation dispersion of polymer melts: Intrasegment, intrachain, and interchain contributions
Proton and deuteron field-cycling NMR relaxometry was applied to deuterated and undeuterated bulk polyethyleneoxide and polybutadiene melts and mixtures thereof with molecular weights above the critical value. Spin-lattice relaxation data due to intrasegment (quadrupolar) couplings and intra- and interchain (dipolar) interactions were evaluated. Diverse dynamic limits are identified both with the proton and deuteron frequency dispersion data. The comparison between the intrachain and the interchain contributions leads to the conclusion that only model theories based on largely isotropic chain dynamics can account for the experimental findings. The extremely anisotropic character of the well-known tube/reptation model is too restrictive in this respect. © 2007 American Institute of Physics
A Salt Metathesis Route To Ruthenium Carbene Complex Isomers With Pyridine Dicarboxamide-Derived Chelate Pincer Ligands
Reaction of the doubly deprotonated pyridine 2,6-dicarboxamido ligand (1) with (PCy_3)_2Cl_2 Ru=CHPh (3a) in THF gave a mixture of (lig)(PCy_3)Ru=CHPh isomers (4). The pentane soluble N,N,O-4 isomer was isolated by extraction and characterized by X-ray diffraction. The O,N, O-4 isomer was identified in the residue. Single crystals of the closely related complex (lig)(NHC) Ru=CHPh, O,N,O-5, were obtained from the reaction of 1 with (NHC)(PCy_3)Cl_2Ru=CHPh (3b) and used for the X-ray crystal structure analysis of the system
Reversible Metal-Free Carbon Dioxide Binding by Frustrated Lewis Pairs
Frustrated Lewis pairs comprising phosphine and borane react to reversibly bind and release CO2, offering a rare example of metal-free CO2 sequestration. The mechanism of formation of CO2 derivatives by almost simultaneous P-C and O-B bond formation was characterized by quantum chemical calculations
A Local Superlens
Superlenses enable near-field imaging
beyond the optical diffraction
limit. However, their widespread implementation in optical imaging
technology so far has been limited by large-scale fabrication, fixed
lens position, and specific object materials. Here we demonstrate
that a dielectric lamella of subwavelength size in all three spatial
dimensions behaves as a compact superlens that operates at infrared
wavelengths and can be positioned to image any local microscopic area
of interest on the sample. In particular, the lamella superlens may
be placed in contact with any type of object and therefore enables
examination of hard-to-scan samples, for example, with high topography
or in liquids, without altering the specimen design. This lamella-based
local superlens design is directly applicable to subwavelength light-based
technology, such as integrated optics
Microscopic Model of Charge Carrier Transfer in Complex Media
We present a microscopic model of a charge carrier transfer under an action
of a constant electric field in a complex medium. Generalizing previous
theoretical approaches, we model the dynamical environment hindering the
carrier motion by dynamic percolation, i.e., as a medium comprising particles
which move randomly on a simple cubic lattice, constrained by hard-core
exclusion, and may spontaneously annihilate and re-appear at some prescribed
rates. We determine analytically the density profiles of the "environment"
particles, as seen from the stationary moving charge carrier, and calculate its
terminal velocity as the function of the applied field and other system
parameters. We realize that for sufficiently small external fields the force
exerted on the carrier by the "environment" particles shows a viscous-like
behavior and define an analog of the Stokes formula for such dynamic
percolative environments. The corresponding friction coefficient is also
derived.Comment: appearing in Chem. Phys. Special Issue on Molecular Charge Transfer
in Condensed Media - from Physics and Chemistry to Biology and
Nano-Engineering, edited by A.Kornyshev (Imperial College London), M.Newton
(Brookhaven Natl Lab) and J.Ulstrup (Technical University of Denmark
Lattice gas model in random medium and open boundaries: hydrodynamic and relaxation to the steady state
We consider a lattice gas interacting by the exclusion rule in the presence
of a random field given by i.i.d. bounded random variables in a bounded domain
in contact with particles reservoir at different densities. We show, in
dimensions , that the rescaled empirical density field almost surely,
with respect to the random field, converges to the unique weak solution of a
non linear parabolic equation having the diffusion matrix determined by the
statistical properties of the external random field and boundary conditions
determined by the density of the reservoir. Further we show that the rescaled
empirical density field, in the stationary regime, almost surely with respect
to the random field, converges to the solution of the associated stationary
transport equation
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