Study of neutral species coordination by macrocyclic anion receptors using FTIR spectroscopy

Complexation ability for two various macrocyclic receptors applied previously as anion receptors to poly(ethylene oxide)-based solid polymer electrolytes was studied by means of FTIR spectroscopy. We have proved that the interactions between neutral species (solvent) and receptors depend both on the donor properties of the solvent and type of the functional groups in receptor. For solvent characterized by similar dielectric constant and coordinating properties (donor and acceptor numbers) like 1,2-dimethoxyethane and its high molecular weight analogues-poly(ethylene oxide) interactions are also affected by steric effect.     

Viscosity-Pressure Correlation of Liquids

A single correlation was obtained to predict Newtonian viscosity-pressure coefficients of mineral oils, resin and polymer blends, pure hydrocarbons, and nonhydrocarbons. The correlation has been tested for a temperature range from 0°c (32 °F) to 135°C (275 °F). The empirical correlation makes use of atmospheric viscosity and density at the temperature of interest and viscosity-temperature property (m_o) of the fluids. When the correlation was compared with other leading correlations, it was shown to require less physical-property data, apply to n wider range of chemical compositions, cover a wider range in fluidity, and provide greater accuracy. The correlation is presented in the form of a polynominal equation.     

A definition of partial derivative of random functions and its application to RBFNN sensitivity analysis

Considering the inputs of a feed-forward neural network as random variables, this paper proposes a definition of partial derivative of a function with respect to a random variable in the probability measure space. The mathematical expectation of the mean square or absolute value of the partial derivative is regarded as a type of measure of the network's sensitivity, which extends Zurada's sensitivity definition of networks in Zurada et al, [Perturbation method for deleting redundant inputs of perceptron networks, Neurocomputing 14 (1997) 177–193] from the certain environment to the stochastic environment. Furthermore, for the purpose of network's redundant feature deletion or feature selection, the new sensitivity measure is applied to the sensitivity analysis of Radial Basis Function Neural Networks (RBFNNs). The feasibility and the effectiveness of the sensitivity approach to redundant feature deletion are illustrated.     

Fuzzy QFD for supply chain management with reliability consideration

Although many products are made through several tiers of supply chains, a systematic way of handling reliability issues in a various product planning stage has drawn attention, only recently, in the context of supply chain management (SCM). The main objective of this paper is to develop a fuzzy quality function deployment (QFD) model in order to convey fuzzy relationship between customers needs and design specification for reliability in the context of SCM. A fuzzy multi criteria decision-making procedure is proposed and is applied to find a set of optimal solution with respect to the performance of the reliability test needed in CRT design. It is expected that the proposed approach can make significant contributions on the following areas: effectively communicating with technical personnel and users; developing relatively error-free reliability review system; and creating consistent and complete documentation for design for reliability.     

Organic polymer thick film light emitting diodes (PTF-OLED)

A guest–host approach was used to fabricate a one-layer organic light emitting diode (OLED). The thick film ink approach allows the two-dimensional OLED to be processed using traditional methods such as silk-screen printing. The I–V–L characteristics of the polymer thick film (PTF)-OLED were studied as a function of the device chemical compositions and physical configurations. Different polymers, hole and electron transporters, and emitters at different weight ratios were studied for its composition dependence. Device configuration also plays a significant role on its overall performance. Dependence on film thickness, electrode type, and the usage of additional charge injection layers were also investigated. The simplified one-layer device allows a straightforward interpretation for the charge-transport and recombination phenomena which shed light for its future improvement.     

Experimental measurements of gold nanoparticle nucleation and growth by citrate reduction of HAuCl4

Gold particle nucleation and growth were analyzed systematically by UV–vis, ELS and TEM measurements. The gold seed particles ranging from 14.3 nm to 20.3 nm were prepared with monodisperse size distribution by citrate reduction reaction of various initial HAuCl₄ concentrations. Gold nanoparticles of different sizes were made by the seed-mediated growth process. In the first stage of seed-mediated growth, most of gold precursors were used for the growth of seed particles, but, further supply of gold precursors promotes the nucleation of small particles and decreases the average particle diameters while the polydispersity of particles increases. This research can be used as basic data to prepare gold nanoparticles with specific properties for different applications.     

Analysis of SiC fibres and composites using Raman microscopy

The application of Raman spectroscopy in the analysis of the microstructure of SCS-6 silicon carbide fibres using a Renishaw Raman microscope is described. It is demonstrated that the technique allows a detailed study to be made of the point-to-point variation in microstructure across a fibre section. It has been possible to monitor the variation of the concentration of SiC and carbon in the fibre microstructure and to detect differences in the forms of carbon present. It is also shown that Raman spectroscopy can be used to follow the micromechanics of both the deformation of silicon carbide fibres and of the fibres within a model composite. Well-defined Raman spectra have been obtained from a variety of Nicalon and Tyranno fibres and the positions of the Raman bands shown to shift on the application of stress or strain. From such stress-induced Raman band shifts, the point-to-point variation of axial fibre stress or strain along an individual fibre in an epoxy matrix can be determined. An example is given of the use of the technique to map the distributions of axial fibre strain in a Nicalon/epoxy fragmentation test specimen and to model the failure processes at the fibre/matrix interface.     

Effects of myosin light chain kinase inhibitors on carbachol-activated nonselective cationic current in guinea-pig gastric myocytes

The effects of myosin light chain kinase inhibitors on muscarinic stimulation-activated nonselective cationic current (ICCh) in guinea-pig gastric antral myocytes were studied using the whole-cell patch-clamp technique. ICCh was induced by carbachol (CCh, 50 microM) at a holding potential of -30 mV or -60 mV. ML-7, a chemical inhibitor of myosin light chain kinase (MLCK), inhibited ICCh concentration dependently in a reversible manner (53 +/- 8.6% at 1 microM, mean +/- SE, n = 11). In addition, amplitudes of ICCh were only 37 +/- 2.7% of the daily control values following the addition of a peptide inhibitor of MLCK to the pipette solution. On the other hand, ML-7 had an inhibitory effect on voltage-operated Ca2+ channel current. The peak value of Ba2+ current at 0 mV was reduced to 35 +/- 7.4% (n = 9) by 3 microM of ML-7. As ICCh is known to have an intracellular Ca2+ dependence, we tried to exclude the possibility that ML-7 inhibited ICCh indirectly via suppression of Ca2+ current and the similar inhibitory effects of ML-7 on ICCh were confirmed under the following conditions: (1) clamp of membrane potential at -60 mV; (2) clamp of intracellular [Ca2+] to 1 microM by 10 mM BAPTA; (3) pre-inhibition of Ca2+ channel by verapamil. Different from the effects on ICCh, ML-7 barely inhibited the same cationic current induced by guanosine 5'-O-(3-thiotriphosphate) (GTP[gammaS], 0.2 mM) in the pipette solution. These results suggest that a Ca2+/calmodulin-MLCK-dependent pathway can modulate the activation of ICCh in guinea-pig gastric antral myocytes.