Search results for "FN"
showing 10 items of 862 documents
Standard Definitions of Persistence Length Do Not Describe the Local “Intrinsic” Stiffness of Real Polymer Chains
2010
On the basis of extensive Monte Carlo simulations of lattice models for linear chains under good and Θ solvents conditions, and for bottle-brush polymers under good solvent conditions, different me...
Influence of chain stiffness on knottedness in single polymers.
2013
In the present article, we investigate and review the influence of chain stiffness on self-entanglements and knots in a single polymer chain with Monte Carlo simulations spanning good solvent, theta and globular phases. The last-named are of particular importance as a model system for DNA in viral capsids. Intriguingly, the dependence of knot occurrence and complexity with increasing stiffness is non-trivial, but can be understood with a few simple concepts outlined in the present article.
Unconventional ordering behavior of semi-flexible polymers in dense brushes under compression
2014
Using a coarse-grained bead-spring model for semi-flexible macromolecules which form a polymer brush, the structure and dynamics of the polymers were investigated, varying the chain stiffness and the grafting density. The anchoring conditions for the grafted chains were chosen such that their first bonds were oriented along the normal to the substrate plane. The compression of such a semi-flexible brush by a planar piston was observed to be a two-stage process: for a small compression the chains were shown to contract by "buckling" deformation whereas for a larger compression the chains exhibited a collective (almost uniform) bending deformation. Thus, the stiff polymer brush underwent a 2n…
Competition between liquid-crystalline ordering and glassy freezing in melts of semiflexible polymers: A monte carlo simulation
1999
We present results of a Monte Carlo simulation of dense melts of semiflexible polymers using the bond-fluctuation model. The chosen Hamiltonian increases the chain stiffness upon cooling which in turn leads to glass-transition like freezing of the polymer mobility. Employing an efficient simulation algorithm, which is able to equilibrate the simulated systems to lower temperature than the Rouse-type algorithm showing the glassy freezing, we are able to observe an isotropic-nematic phase transition. This transition lies above the glass transition temperature one would extrapolate from the observed freezing behavior.
ChemInform Abstract: New Binary Antimonide Hf5Sb3 - Differences and Similarities to the Zr Antimonides.
2010
Abstract Hf5Sb3 can be prepared by arc-melting of hafnium and previously synthesized HfSb2. It crystallizes like the high-temperature modification of Zr5Sb3 in the Y5Bi3 structure type, space group Pnma, Z=4, a=740.75(9) pm, b=871.8(1) pm, c=1073.6(1) pm, V=693.3(1) 106pm3. An antimonide analogous to the low-temperature form of Zr5Sb3 was not obtained during our investigations. In the structure of Hf5Sb3, the Hf atoms form a three-dimensional network with numerous short Hf–Hf contacts, including the Sb atoms in severely distorted two- and three-capped trigonal prismatic voids. Calculations of the electronic structure, performed with the extended Huckel approximation as well as the TB-LMTO-A…
Fiberless, Multi-Channel fNIRS-EEG System Based on Silicon Photomultipliers: Towards Sensitive and Ecological Mapping of Brain Activity and Neurovasc…
2020
Portable neuroimaging technologies can be employed for long-term monitoring of neurophysiological and neuropathological states. Functional Near-Infrared Spectroscopy (fNIRS) and Electroencephalography (EEG) are highly suited for such a purpose. Their multimodal integration allows the evaluation of hemodynamic and electrical brain activity together with neurovascular coupling. An innovative fNIRS-EEG system is here presented. The system integrated a novel continuous-wave fNIRS component and a modified commercial EEG device. fNIRS probing relied on fiberless technology based on light emitting diodes and silicon photomultipliers (SiPMs). SiPMs are sensitive semiconductor detectors, whose large…
Photoplethysmography Analysis of Artery Properties in Patients with Cardiovascular Diseases
2008
In this study arterial parameters of healthy subjects were compared to those of patients with cardiovascular diseases. The photoplethysmography (PPG) measurements of blood volume pulsations have been performed. Using a novel algorithm for analysis of simultaneously measured ear and finger PPG signals, arterial parameters were evaluated in representative groups of healthy subjects and patients with cardiovascular diseases. Digital volume pulse (DVP), pulse cycle duration (T), augmentation index (AIx), reflection index (RI) and transit time of reflected wave (RTT) were evaluated in every heartbeat cycle. Correlations between the AIx and RI, T and RTT, AIx and standard deviation of AIx, RTT an…
Współpraca miast województwa opolskiego z partnerami niemieckimi z perspektywy 25 lat realizacji Traktatu o dobrym sąsiedztwie i przyjaznej współpracy
2016
The study undertakes the conclusions of partnership agreements between the cities of the Opole voivodeship and the German cities. It presents the number of partnerships, their geographical structure and the periodization of signing contracts. The main factors that contribute to the development of that form of cooperation, as well as the obstacles on the way are discussed. Attention is drawn to the most important forms of cooperation and the benefits that derive from it for the both sides. Among the most important results of that cooperation are mentioned: the formation of a civil society features among the residents of partnership cities, the improvement of the image of both countries and n…
Socio-emotional Problems Experienced by Deaf and Hard of Hearing Students in Ethiopia
2015
This study compares the socio-emotional problems experienced by deaf and hard of hearing (DHH) students with those of hearing students in Ethiopia. The research involved a sample of 103 grade 4 students attending a special school for the deaf, a special class for the deaf and a regular school. Socio-emotional problems were measured using Goodman's self-report measure, the Strengths and Difficulties Questionnaire for children and adolescents. Participants were selected from seven towns in Ethiopia. The results show that, compared to the hearing sample, the DHH students experienced more severe socio-emotional problems across all dimensions, regardless of whether they were in special classes o…
Time reproduction of structured auditory events by deaf and hearing subjects
2009
Congenital deafness affects different aspects of information processing and time perception. In deafness the accuracy of duration judgments seems to be linked to differences in the use of conventional time units, applied strategy as well as cognitive processes such as attention or working memory (Kowalska & Szelag, 2006). The present experiment investigated the effect of different event structures on duration reproduction in deaf and normal hearing subjects. The accuracy and variability of performances were calculated respectively by means of the absolute error score and coefficient of variation of time reproductions. Results showed a global underestimation of durations for all subjects; mo…