Search results for "Tact"
showing 10 items of 1313 documents
Stability of thin polymer films: influence of solvents.
2004
The interface and surface properties and the wetting behavior of polymer-solvent mixtures are investigated using Monte Carlo simulations and self-consistent field calculations. We carry out Monte Carlo simulations in the framework of a coarse-grained bead-spring model using short chains (oligomers) of N(P)=5 beads and a monomeric solvent, N(S)=1. The self-consistent field calculations are based on a simple phenomenological equation of state for compressible binary mixtures and we employ Gaussian chain model. The bulk behavior of the polymer-solvent mixture belongs to type III in the classification of van Konynenburg and Scott [Phil. Trans. R. Soc. London, Ser. A 298, 495 (1980)]. It is char…
On the applicability of density dependent effective interactions in cluster-forming systems
2016
We systematically studied the validity and transferability of effective, coarse-grained, pair potentials in ultrasoft colloidal systems. We focused on amphiphilic dendrimers, macromolecules which can aggregate into clusters of overlapping particles to minimize the contact area with the surrounding (implicit) solvent. Simulations were performed for both the monomeric and coarse-grained model in the liquid phase at densities ranging from infinite dilution up to values close to the freezing point. For every state point, each macromolecule was mapped onto a single interaction site and the effective pair potential was computed using a coarse-graining technique based on force-matching. We found e…
Nonlinear dynamics of semiflexible magnetic filaments in an ac magnetic field
2006
Flexible spontaneously magnetized filaments exist in the living world (magnetotactic bacteria) and arise in magnetic colloids with large magnetodipolar interaction parameter. We demonstrate that these filaments possess variety of novel nonlinear phenomena in an ac magnetic field: orientation of the filament in the direction perpendicular to the field and the development of the oscillating U-like shapes, which presumably can lead to the formation of rings of magnetic filaments. It is found that these phenomena are determined by the development of the localized boundary modes of the filament deformation. We have illustrated by qualitative estimates that the phenomena found may be useful for i…
<strong>Predicting Proteasome Inhibition using Atomic Weighted Vector and Machine Learning</strong>
2018
Ubiquitin/Proteasome System (UPS) is a highly regulated mechanism of intracellular protein degradation and turnover. Through the concerted actions of a series of enzymes, proteins are marked for proteasomal degradation by being linked to the polypeptide co-factor, ubiquitin. The UPS participates in a wide array of biological functions such as antigen presentation, regulation of gene transcription and the cell cycle, and activation of NF-κB. Some researchers have applied QSAR method and machine learning in the study of proteasome inhibition (EC50(µmol/L)), such as: the analysis of proteasome inhibition prediction, in the prediction of multi-target inhibitors of UPP and in the prediction of p…
Far-infrared laser on quantum dots created by electric-field focusing
2003
The new proposal of a far-infrared laser employing intraband transitions in the system of quantum dots is briefly described. The conditions for inversion of population for electrons in the quantum dot matrix created by an electric-field focusing in narrow GaAs/AlGaAs quantum well are discussed. The laser is planned to be pumped by periodically repeated rapid creation and destruction of the quantum dot matrix allowing for repeated filling of the dot levels with electrons from a quantum well. Some major results of the analysis of the kinetics of the electron-photon system are presented.
Study of the long-period changes in samples of isotactic poly(propylene) obtained by quenching from the melt and subsequent annealing at different te…
1997
The structural modifications induced in samples of isotactic poly(propylene) obtained by quenching from the melt at 100°C/s and subsequently annealed at 40, 60 and 80°C for different annealing times have been studied using simultaneous wide-angle and small-angle X-ray scattering at the synchrotron radiation source of DESY. The occurrance of two different long-period values is demonstrated. These values are related to the mesomorphic phase, existing in the starting quenched material, and to the α-monoclinic one, which settles during the annealing process, respectively.
The X-ray determination of the amounts of the phases in samples of isotactic poly(propylene) quenched from the melt at different cooling rates
1997
A new procedure for the determination of the amounts of phases in samples of isotactic poly(propylene) quenched at different cooling rates from the same melted polymer is described. According to the procedure, all the patterns corresponding to the same quenching series are simultaneously analyzed for the amounts of phases so that reliable phase fractions relative to the different samples of the series are achieved. The analysis of the results points out that for increasing cooling rates above 30°C/s a remarkable increase of the mesomorphic phase settles, mainly at the expense of the α-monoclinic one.
Generation of narrowband antisymmetric lamb waves using a formed laser source in the ablative regime
2007
A formed laser source, using a four-element lenticular array, is used in the ablative regime to generate select, narrowband, acoustic plate waves. The arrangement of the array produces acoustical signals that have frequencies compatible with the response of the broadband capacitive air-coupled transducer used in this study. A simplified concept is presented to explain the effect of a line array source on the frequency content of acoustic waves. The analytical model for a point pulse surface displacement is derived from the point load solution to Lamb's problem. The point pulse displacement elements of a line array source are summed mathematically, taking into account all applicable propagat…
Improvement of the wettability and dissolution of fenofibrate compacts by plasma treatment
2011
Abstract The goal of this study was to investigate the effect of plasma treatment on the wettability and dissolution of fenofibrate compacts. Contact angle measurements and intrinsic dissolution rate studies of untreated and plasma-treated fenofibrate compacts were conducted. The contact angle data clearly show that the wettability of the tablet surface increased with the duration of plasma treatment. Analyses of stability revealed that the surfaces which were plasma-treated for more than 1 min regained some degree of hydrophobicity after storage in air. Since their hydrophobic recovery finally reached the level observed with 1 min plasma-treated fenofibrate compacts it was deduced that per…
Mechanically stable metal layers for ohmic and blocking contacts on CdZnTe detectors by electroless deposition
2015
CdZnTe detectors are commonly exploited for the detection of gamma rays. However, obtaining mechanical stable, low noise contacts on CdZnTe is still an issue. In particular, ohmic contacts would be preferable for high flux applications. In this work, we show that it is possible to obtain mechanical stable gold contacts by electroless deposition in methanol solution. Moreover, we show that electroless deposited nickel contacts are also mechanical stable and are good candidates for the realization of ohmic contacts on high resistivity CdZnTe crystals.