Difference between heartwood and sapwood
Forest Products Laboratory (U.S.)
1919
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We consider the nearest neighbors one-dimensional totally asymmetric simple
exclusion process starting with ones to the left of the origin, a second class
particle at the origin, a third class particle at site 1 and no particles to
the right of site 1. We show that the probability that the third class
particle is to the right of the second class particle at time $t$ converges to
$2/3$ as $t\to\infty$. We also consider the asymmetric exclusion
process with transition rates having a positive mean and show that if the
system starts with a product measure with densities $\lambda>\rho$ to the left
and right of the origin, respectively, then the position of the second class
particle at time $t$ divided by $t$ converges in distribution to a uniform
random variable in the interval $[-(\rho-\lambda),\rho-\lambda]$, extending...
In this paper we consider the one-dimensional weakly asymmetric simple exclusion process under the invariant state $\nu_{\rho}$: the Bernoulli product measure of parameter $\rho\in{(0,1)}$. We show that the limit density field is governed by
an Ornstein-Uhlenbeck process for strength asymmetry $n^{2-\gamma}$ if $\gamma\in(1/2,1)$, while for $\gamma=1/2$ it
is an energy solution of the KPZ equation. From this result we obtain that the fluctuations of the current of particles are Gaussian distributed for $\gamma\in(1/2,1)$, while for $\gamma=1/2$ the limit distribution is written in terms of the KPZ equation.
If the future global future energy needs are to be met, renewable energies must be exploited. The possibility of cheap, but efficient organic or polymer based photovoltaic (OPV) devices are among the competing technologies, which are actively being studied. To date the most efficient OPV devices are based on conjugated polymer-fullerene bulk heterojunctions (BHJ). The choice of polymer and fullerene is a balance of electronic (donor-acceptor) properties, but due to the nature of the solubility of the species, also includes solubilising ligands. Whilst these ligands certainly induce improved solution processability, they can also affect the electronic characteristics and also morphology of the polymers and fullerenes. However, potentially interesting polymer-fullerene combinations are not being explored due to difficulties in solution p...
In these notes we use renormalization techniques to derive a second order Boltzmann-Gibbs Principle which allow us to characterize the equilibrium fluctuations of weakly asymmetric exclusion processes as within the KPZ universality class.
Polymer based photovoltaic devices promise solar technologies that are inexpensive enough to be widely exploited and therefore provide a significant fraction of the future energy needs. There are many promising polymer-fullerene mixtures that are promising materials candidates for achieving high performance devices, but their exploitation requires and improved understanding of their structure-property relationships. Of particular relevance is the phase behavior of the mixtures.
The phase behavior of donor-acceptor materials for photovoltaic applications is of key importance [1,2]: i) to gain a fundamental understanding and control of morphology development in the donor-acceptor blends; ii) to appropriately choose the operating window for thermal annealing; iii) to understand the long-term stability of the blended film morphology and ...
A series of complexes trans-[FMo(N=NCHL)(dppe)2][BF4] (L = (bi)thienyl or arylthienyl), were synthesized and fully characterized by 1H, 13C, 31P NMR, IR and UV–Vis spectroscopies. The electronic spectra and electrochemical behavior of the complexes were investigated. The electronic absorption spectra of these complexes display a broad low-energy band in the visible region attributable to metal-to ligand charge transfer (MLCT) transitions. The electron conjugated effect with the heterocyclic nucleus led to a notable improvement of visible light absorption and marked changes in the electrochemical behavior. The hyperpolarizabilities beta of the synthesized compounds were evaluated using the hyper-Rayleigh scattering technique.
Six new thiophene oligomers, here designated as tripodal-like oligothienyl imidazoles, were synthesized and have been investigated in ethanol solution at room and low temperature. The oligomers bear a common core where two or more thiophenes are linked to one or more imidazole unit which further links through its alpha position to a different number of incremental thiophene units. The study involves a comprehensive spectral and photophysical investigation where the properties of the singlet and triplet states have been investigated regarding absorption, fluorescence and phosphorescence, transient triplet-triplet absorption together with all relevant quantum yields (fluorescence, internal conversion, intersystem crossing and singlet oxygen) and lifetimes. In addition, DFT quantum chemical calculations were performed to gain a detailed u...
Mixing in microsystems, combining alternate flow with obstacles, is studied by numerical methods. Simulations show that the layers of high and low solute concentrations, created by the alternate flow, are split into smaller chunks of fluid by obstacles inserted in the mixing channel, decreasing the critical mixing length. Reverse flow is necessary to guarantee symmetry and good mixing. Mixing increases with the increase of the number of obstacles. Increase of frequency improves mixing but requires an increase of reverse flow. The improvement in the mixing process shows that this method is very useful for designing mixers for lab-on-a-chip devices.
Most cases of candidosis have been attributed to Candida albicans, but recently non-Candida albicans Candida species have been identified as frequent human pathogens. Candida pathogenicity has been attributed to several factors, including adhesion to medical devices and/or host cells, biofilm formation, and secretion of hydrolytic enzymes (proteases, phospholipases, and haemolysins). Although ‘new’ Candida species are emerging, there is still a lack of information about their pathogenicity. This review discusses recent advances in our knowledge of C. glabrata, C. parapsilosis, and C. tropicalis virulence factors, specifically those of adhesion and biofilm formation, which are key components in Candida pathogenicity.
Sugar esters are compounds with surfactant properties (biosurfactants), i.e., capable of reducing the surface tension and promote the emulsification of immiscible liquids. On the other hand, as with all emulsions, coconut milk is not physically stable and is prone to phase separation. Therefore, the aim of this work was to evaluate the synthesis of fructose, sucrose and lactose esters from the corresponding sugars using Candida antarctica type B lipase immobilized in two different supports, namely acrylic resin and chitosan, and evaluate its application in the stabilization of coconut milk emulsions. The enzyme immobilized on chitosan showed the highest yield of lactose ester production (84.1%). Additionally, the production of fructose ester was found to be higher for the enzyme immobilized on the acrylic resin support (74.3%) as compa...
