New N,O-containing ligands for the biomimetic copper-catalyzed polymerization of 2,6-dimethylphenol

Poly(2,6-dimethyl-1,4-phenylene ether) (PPE), which is widely used in high-performance engineering plastics, is obtained by the copper-catalyzed oxidative coupling of 2,6-dimethylphenol. The oxidative polymerizations have been carried out in acetonitrile with structurally related [copper-(N,O-containing ligand)] complexes as the catalyst precursor compounds, which appeared to be of great interest for a better understanding of the factors influencing the catalytic activities. Steric effects (influence of a methyl group close to the metal center; ligands 4–7) or electronic effects (imino versus amino group; ligands 4, 5, 8 and 6, 7, 9, respectively) on the polymerization rates have been demonstrated. The use of mono- or dinucleating ligands has strengthened the proposed mechanism of the reaction involving dinuclear active species.     

Note: Simultaneous electrical and optical detection of expanding dense partially ionized vapour clouds

The scheme and construction of an electro-optical probe able to collect charge and detect optical emission from expanding dense partially ionized vapour clouds are reported. The instrument can be applied to phenomena such as dust impact ionization and solid target laser ablation. First, results of measurements of expanding plasma cloud formed upon ablating W target are presented. Use of the instrument in different experimental facilities, including tokamak, is discussed.     

Convergence in Networks With Counterclockwise Neural Dynamics

The notion of counterclockwise (ccw) input-output (I-O) dynamics, introduced by Angeli (2006) to deal with questions of multistability in interconnected dynamical systems, is applied and further developed in order to analyze convergence and stability of neural networks. By pursuing a modular approach, we interpret a cellular nonlinear network (CNN) as a positive feedback of a parallel block of single-input-single-output (SISO) dynamical systems, the neurons, and a static multiple-input-multiple-output (MIMO) system that couples them (typically the so-called interconnection matrix). The analysis extends previously known results by enlarging the class of allowed neural dynamics to higher order neurons.     

Introducing realistic tire–pavement contact stresses into Pavement Analysis using Nonlinear Damage Approach (PANDA)

Realistic tire–pavement interface contact areas and stresses were incorporated into the Pavement Analysis using Nonlinear Damage Approach (PANDA) user interface (PUI). PANDA is a software library developed to simulate the complex thermo-viscoelastic–viscoplastic–viscodamage responses of the pavement to mechanical and environmental loads. The PUI is an interface generating a finite element representation of the pavement within PANDA. The application of realistic tire loading is necessary to calculate accurate pavement responses. The PUI incorporates a database of tire contact areas and stresses obtained from tire finite element simulations. The database includes tire interface characteristics with pavements for various applied loads, tire inflation pressures, vehicle speeds and scenarios of different rolling simulations. A parametric study was conducted to investigate the effect of simulations of tire contact stresses that match field measurements on viscoelastic and viscoplastic pavement responses. Pavement responses are greatly affected using realistic tire loading contact stresses and contact geometry as compared to simplified contact models. The impact on rutting and damage predictions cannot be ignored if reliable projections of pavement performance are to be made. This study confirms the importance of considering realistic three-dimensional contact stresses to design and analyse pavements.     

Innovative techniques in pediatric liver transplantation: reduced-, split- and living-donor related liver transplantation

BACKGROUND: Biological systems that show threshold phenomena are candidates for stochastic resonance as a mechanism to explain what appears to be biovariability. Stochastic resonance is the amplification of weak signals by "noise." OBJECTIVE: This review discusses the areas of contact dermatitis in which threshold events have been documented. The purpose is to point out the mechanism by which stochastic resonance may affect patch test results. METHODS: A literature review technique was used. RESULTS: The recent finding of a neurological influence on contract dermatitis provides a mechanism for stochastic resonance to affect patch test results. CONCLUSION: Stochastic resonance is likely to affect patch test results when more than one patch test result is positive.     

A Model-Based Method for an Online Diagnostic Knowledge-Based System

Fault diagnosis is very important for modern production technology and has received increasing theoretical and practical attention during the last few years. This paper presents a model-based diagnostic method for industrial systems. An online, real-time, deep knowledge based fault detection system has been developed by combining different development environments and tools. The system diagnoses, predicts and compensates faults by coupling symbolic and numerical data in a new environment suitable for the interaction of different sources of knowledge and has been successfully implemented and tested on a real hydraulic system.     

Micromachined scaffolds as primers for cartilage cell growth

Research on the growth and monitoring of cartilage cells in a controlled microstructured environment is important because of the consideration of how the microenvironment affects the cells involved in cartilage regeneration has been neglected to date. An experimental realisation has been demonstrated of biocompatible microstructured surfaces of controlled topography, which have been formed in biocompatible polyimide (Kapton) and in synthetic bioresorbable, epsiv-polycaprolactone (PCL). Bovine cartilage cell growth has been achieved in vitro on the microstructured surfaces and the retention of chondrocytic morphology has been investigated. The results demonstrate that PCL and Kapton microgrooved surfaces can act as primers for cartilage regeneration and repair in vitro or potentially in vivo, by retaining chondrocytic phenotype and enhancing cartilage formation     

CFD-Simulation eines direkt befeuerten Ofens zur Vorbehandlung feuerverzinkter Stahlbänder

For the production of high-quality goods in industrial furnaces using minimal expenditure of energy, optimization of the process parameters is required. One tool for improving the processes economically is the simulation of the furnaces by using Computational Fluid Dynamics (CFD). The pre-heating process of a steel strip in a section of an annealing furnace for surface treatment in a hot-dip galvanizing process was simulated using the commercial CFD software Ansys Fluent 15.0. For combustion, the Equilibrium model is used, turbulence is modeled by the realizable-k-ε model, and radiation is taken into account by using the Discrete Ordinate Method (DOM).     

Mechanical squeezing of an elastomeric nanochannel device: numerical simulations and ionic current characterization

Peculiar transport phenomena appear at nanoscale, since surface effects strongly affect the behaviour of fluids. Electrostatic and steric interactions, capillary forces and entropic effects play a key role in the behaviour of fluids and biomolecules. Since these effects strongly depend on the size of the nanofluidic system, a careful characterization of the fluidic environment is necessary. Moreover, the possibility to dynamically modulate the size of nanochannels is very appealing in the field of biomolecule manipulation. Recently, we have developed a lab-on-chip made of poly(dimethylsiloxane) (PDMS). This polymeric device is based on a tuneable nanochannel able to dynamically change its dimension in order to fit the application of interest. In fact, a mechanical compression applied on the top of the elastomeric device squeezes the nanochannel, reducing the channel cross section and allowing a dynamical optimization of the nanostructures. In this paper, this squeezing process is fully characterized both numerically and experimentally. This analysis provides information on the reduction of the nanochannel dimensions induced by compression as a function of the work of adhesion and of the stiffness of the materials composing the device. Moreover, calculations demonstrate the possibility to predict the change of the nanochannel size and shape induced by the compression. The possibility to dynamically tune the channel size opens up new opportunities in biomolecular sensing or sieving and in the study of new hydrodynamics effects.