Synthesis and characterization of conducting copolymers from aniline and o‐anisidine in HCl solutions

Conducting poly(aniline‐co‐o‐anisidine) (PAS) films with different ratios of aniline units in the polymer chain were prepared by oxidative polymerization of different molar ratios of aniline and o‐anisidine in 1 M HCl using cyclic voltammetry. Due to the much higher reactivity of o‐anisidine, the structure and properties of PASs were found to be dominated by the o‐anisidine units. The polymerization of poly‐o‐anisidine and PASs followed zero‐order kinetics with respect to formation of the polymer (film thickness) and the autocatalytic polymerization of aniline was completely inhibited. In contrast to polyaniline, a decrease in the polymerization temperature was found to increase the amount of copolymer formed and its redox charge. The presence of aniline units in PASs led to a pronounced increase in the molecular weight and conductivity, and a decrease in the solubility in organic solvents. Repetitive charging/discharging cycles showed that PASs resist degradation more than polyaniline. Copyright © 2003 Society of Chemical Industry     

Mining predecessor–successor rules from DAG data

Data mining extracts implicit, previously unknown, and potentially useful information from databases. Many approaches have been proposed to extract information, and one of the most important ones is finding association rules. Although a large amount of research has been devoted to this subject, none of it finds association rules from directed acyclic graph (DAG) data. Without such a mining method, the hidden knowledge, if any, cannot be discovered from the databases storing DAG data such as family genealogy profiles, product structures, XML documents, task precedence relations, and course structures. In this article, we define a new kind of association rule in DAG databases called the predecessor–successor rule, where a node x is a predecessor of another node y if we can find a path in DAG where x appears before y. The predecessor–successor rules enable us to observe how the characteristics of the predecessors influence the successors. An approach containing four stages is proposed to discover the predecessor–successor rules. © 2006 Wiley Periodicals, Inc. Int J Int Syst 21: 621–637, 2006.     

Optical-transmission characteristics of optical-fiber cables and installed optical-fiber cable networks for WDM systems

Many cables containing 1.3-/spl mu/m zero-dispersion single-mode (SM) optical fibers are installed in trunk and access networks. Recently, there have been a number of studies on wavelength-division-multiplexing (WDM) systems designed to increase transmission capacity and flexibility. If we can construct WDM systems using SM optical-fiber cable networks designed to transmit using wavelengths in the 1.3-/spl mu/m window (O-band), this will prove very effective in reducing construction costs. It is therefore important to examine the wavelength dependence of the transmission characteristics of SM optical-fiber cables and networks that have already been installed and in which several optical fibers are joined. In this paper, we describe the measured optical characteristics of SM optical-fiber cables and installed optical-fiber cable networks at various wavelengths. The optical characteristics were stable in the 1.46 to 1.625-/spl mu/m wavelength range and we confirmed that the installed SM optical-fiber cable networks could be used for WDM system applications.     

Kommunikationsoberfläche Membran‐ Vorbild für moderne Nanoanalytik

A central event in the life of a cellular system is the interaction between the exterior and the interior compartments. Biochemical signals arrive at the cellular surface, bind to their membrane bound receptor followed by a conformational change triggering the release of an internal chemical or electrical signal.This basic principle is followed by all our perceptive abilities like sense of smell or taste, but also by different signal transduction pathways involved in nerve conductivity, vision, sense of touch or hearing. To follow and mimic this principle of parallel registration is one of the aims of modern nanobiotechnology. If we are able to specifically biofunctionalize small arrays of a solid surface, which could be an electrode or a semiconductor, this approach will enable us to build up devices called “biochips” or “biosensors” that allow the determination of bioactive molecules with high specificity at lowest concentrations. Potential pharmacological active substrates might be screened as well as new receptors may be determined. Applications in genomics as well as proteomics are realistic. The major prerequisite for such a broad spectrum of applications is the fabrication of receptive surfaces. Biomolecules have to be surface‐adsorbed in a highly reproducible, oriented and well organised fashion, a task which in biology is taken by the cellular membranes as external or internal receptive surfaces. The physical principles like hydrogen bonds, electrostatic or hydrophobic interactions that lead to such an organized surface are well known. To synthesize molecular building blocks and to position them onto an otherwise unspecific surface is one of the challenges of nanobiotechnology combining biological knowledge and chemical skills with biophysical techniques that allow to handle or analyze even single molecules.     

Microscale Patterning of Mesoscopic PZN-PT Single Crystal Films by Crystal ion Slicing and Laser-Induced Etching

Advances in the fabrication of solid-solution single crystal relaxor ferroelectrics have made it possible to produce highly efficient piezoelectric crystals, and have attracted renewed interest in the use of these crystals for a new generation of piezoelectric transducers, actuators and sensors. Of particular interest is their incorporation into micro-electromechanical systems (MEMS). In this paper we report on the laser-induced wet chemical etching of lead zinc niobate-lead titanate (PZN-PT) in hydrochloric acid (HCl). Argon-ion laser radiation at power levels up to 4 W is focused to a spot diameter of about 15μm and results in the chemical etching of grooves at patterning speeds up to 5μm/sec. Crystal ion slicing, an ion-implant-based film separation technique, is used in combination with laser etching to form 5 to 10μm-thick patterned and freestanding films for incorporation into micro-electromechanical devices.     

A VQ-based blind image restoration algorithm

Learning-based algorithms for image restoration and blind image restoration are proposed. Such algorithms deviate from the traditional approaches in this area, by utilizing priors that are learned from similar images. Original images and their degraded versions by the known degradation operator (restoration problem) are utilized for designing the VQ codebooks. The codevectors are designed using the blurred images. For each such vector, the high frequency information obtained from the original images is also available. During restoration, the high frequency information of a given degraded image is estimated from its low frequency information based on the codebooks. For the blind restoration problem, a number of codebooks are designed corresponding to various versions of the blurring function. Given a noisy and blurred image, one of the codebooks is chosen based on a similarity measure, therefore providing the identification of the blur. To make the restoration process computationally efficient, the principal component analysis (PCA) and VQ-nearest neighbor approaches are utilized. Simulation results are presented to demonstrate the effectiveness of the proposed algorithms.     

Petroleum naphthenomono-and naphthenobiarenes

The hydrocarbon-group composition and distribution of naphthenoaromatic hydrocarbons of West Siberian oils were studied by the technique of mass spectrometry. Naphthenoaromatic hydrocarbons of the general formula C_nH_2n?z , where z is 8, 10, 12, 14, 16, or 18, containing from one to six saturated cycles are present in oils in significant concentrations. Naphthenomonoarenes with one saturated cycle dominate in all oils. An increase in the amount of compounds containing 3–6 saturated cycles in their molecule with the occurrence depth was noted. Naphthenobiarenes of the general formula C_nH_2n?z , where z is 14, 16, 18, 20, 22, or 24 containing from one to six saturated cycles are present in oils in concentrations from 20.0 to 54.0 wt % of the biaromatic fraction. Most oils are characterized by the prevalence of structures with one and two saturated cycles in their molecule. The dependence of the number of cycles in naphthenobiarenes on the nature of original organic matter (OM) was not traced. The lack of correlation between the number of cycles and the OM type is presumably due to the fact that, for the most part, fused polycyclic naphthenobiarenes reflect the degree of catagenetic alteration of organic matter.     

Modification of ASM3 for the determination of biomass adsorption/storage capacity in bulking sludge control.

The selector activated sludge (SAS) systems are known to prevent excessive growth of filamentous microorganisms responsible for bulking sludge, but these systems were hardly ever modelled. This study aimed to develop a model capable of predicting rapid substrate removal in the SAS systems. For this purpose, the Activated Sludge Model No. 3 (ASM3) was extended with three processes (adsorption, direct growth on the adsorbed substrate under aerobic or anoxic conditions). The modified ASM3 was tested against the results of batch experiments with the biomass originating from two full-scale SAS systems in Germany. The endogenous biomass was mixed with various readily biodegradable substrates (acetate, peptone, glucose and wastewater) and the utilisation of substrate (expresses as COD) and oxygen uptake rates (OURs) were measured during the experiments. In general, model predictions fitted to the experimental data, but a considerable number of kinetic (5) and stoichiometric (2) parameters needed to be adjusted during model calibration. The simulation results revealed that storage was generally a dominating process compared to direct growth in terms of the adsorbed substrate utilisation. The contribution of storage ranged from 65-71% (Plant A) and 69-92% (Plant B).