Multichromic polymers based on pyrene clicked thienylpyrrole

In this study, the effect of pendant pyrene on the optical and electronic properties of poly(2,5‐dithienylpyrrole)s was studied. For this purpose a new pyrene coupled 2,5‐dithienylpyrrole derivative (SNS‐pyrene) was synthesized through click reaction. SNS‐pyrene was electrochemically polymerized and its electrochemical and optical properties were investigated by electrochemical and optical techniques. The polymer had a band gap of 3.36 eV and displayed light green to blue color variation upon oxidation in less than 2.48 s. Additionally, electrochemical copolymerization of SNS‐pyrene with 3,4‐ethylenedioxythiophene was achieved whilst a detailed investigation was performed on the effect of electrochemical polymerization conditions on the optoelectronic properties of the copolymers. Studies revealed that the copolymers exhibit multichromic reversible redox behavior with lower band gaps and shorter switching times than their parent polymer, P(SNS‐pyrene) © 2014 Society of Chemical Industry.     

加脂的化学柔软作用机理

加脂是软革制造过程中最重要的工序。本文建立了一个加脂过程和加脂机理的模型。在该模型中，传统的完全依赖ＰＨ值的观察被扩展，结合了加脂剂与浴液间的相互作用的性能和传送提供润滑作用的中性油组分的乳化剂的作用，并扩展了乳化剂的角色。以这种方式引入的化学柔软作用对革的强度有积极的效果，而相比效应力柔软作用会降低革的强度。     

Determination of optimum pH and temperature for pasteurization of citrus juices by response surface methodology

Summary Optimization of microbial death, enzyme inactivation and vitamin C retention during pasteurization of pH-adjusted orange juice is discussed free of equipmentdependent parameters such as the heating lag. The pH-temperature optimum was determined by response surface methodology in the range of 65° C–75° C and pH 2.5–4.0. The results implied that there was no pectinesterase activity below pH 3.5.Leuconostoc mesenteroides had its maximum and minimum thermal resistance at pH 3.5 and pH 2.7, respectively. For an ideal theoretical process requiring four log cycles of microbial reduction the optimum pasteurization conditions were 12 min at 75° C and pH 2.7.

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Bestimmung der optimalen Temperatur- und pH-Wert-Bedingungen für die Pasteurisierung von Citrussäften mit der response surface-Methode

Zusammenfassung Die Optimierung der mikrobiellen Abtötung, Enzyminaktivierung und Vitamin-C-Retention während der Pasteurisierung von Orangensaft mit verschiedenen pH-Werten wird, frei von Anlageneinflüssen, wie z. B. Erhitzungsverzögerungen, diskutiert. Das Temperatur-pH-Wert-Optimum wurde mit der response surface-Methode im Temperaturbereich von 65 bis 75 °C und pH-Werten zwischen 2,5 und 4,0 untersucht. Die Ergebnisse lassen darauf schließen, daß unter pH 3,5 keine Pectinesteraseaktivität mehr vorliegt.Leuconostoc mesentroides wies bei pH 2,7 minimale und bei pH 3,5 maximale Hitzeresistenz auf. In einem idealen theoretischen Pasteurisierungsprozeß, der eine Reduzierung der mikrobiellen Belastung um vier Größenordnungen erfordert, liegen die optimalen Bedingungen bei 12 min, 75 °C und einem pH-Wert von 2,7.

     

COMPATIBILITY OF SYSTEMS OF FUZZY RELATION EQUATIONS

In this paper, a fuzzy relation equation system with the generalized conjunction and implication operations is considered. Necessary and sufficient conditions of solvability of this system are proved. The case where these conditions are not fulfilled is considered and the solvability degree of the approximate solution is estimated. The interpolation property of the solution independently on whether it is precise or approximate is established.     

Quantification of structural changes in acute inflammation by fractal dimension,angular second moment and correlation

The aim of the study was to examine alteration and possible application of fractal dimension, angular second moment, and correlation for quantification of structural changes in acutely inflamed tissue. Acute inflammation was induced by injection of turpentine oil into the right and left hind limb muscles of mice, whereas control animals received intramuscular saline injection. After 12 h, animals were anesthetised and treated muscles collected. The tissue was stained by hematoxylin and eosin, digital micrographs produced, enabling determination of fractal dimension of the cells, angular second moment and correlation of studied tissue. Histopathological analysis showed presence of inflammatory infiltrate and tissue damage in inflammatory group, whereas tissue structure in control group was preserved, devoid of inflammatory infiltrate. Fractal dimension of the cells, angular second moment and correlation of treated tissue in inflammatory group decreased in comparison to the control group. In this study, we were first to observe and report that fractal dimension of the cells, angular second moment, and correlation were reduced in acutely inflamed tissue, indicating loss of overall complexity of the cells in the tissue, the tissue uniformity and structure regularity. Fractal dimension, angular second moment and correlation could be useful methods for quantification of structural changes in acute inflammation.     

Lyapunov design for convergence rate improvement in adaptive control

This note deals with the improvement of the convergence rate and robust properties in an adaptive error model. A new adaptive control algorithm is presented which includes both the estimate of the prediction error to drive the parameter adaptation and the proportional-integral or integral-relay adjustment law. To prevent unbounded growth of feedback gains, a least-squares gain update is used. The adaptive controller is constructed using measurements of state variables only. The design is based on the Lyapunov function method and a new general form of the Lyapunov function was found. As a result, exponential convergence of the Lyapunov function in the presence of persistent excitation, is obtained.     

Negative capacitance peculiarities in a-Si:H/c-Si rectifier structure

Nontrivial negative capacitance (NC) effect, observed in a-Si:H/c-Si heterostructure devices, is discussed emphasizing the theoretical interpretation of experimental data. To explain NC effect, we have performed dark current voltage (I-V) and admittance measurements (C-V, G-V, C-f and G-f). The calculated values of series resistance (R_s) and barrier height (Φ_Bo) have the values from 100 to 114.7 Ω and 0.94 to 0.83 eV, respectively. Also, below 50% helium dilution rate, diode ideality factor (n) becomes bigger than 2, because tunneling at junction interface plays a major role. The measured room temperature (294 K) dark I-V result has been used during the fitting process for suggested capacitance model (Eq. (18)). The measured NC values exhibit strongly voltage depended behavior. This unexpected behavior is attributed to the presence of inductively coupled space charge region which might possibly be stemmed from the helium diluted a-Si:H material. It is seen that the measured NC values are well fitted with suggested capacitance model (Eq. (18)). Application of suggested correction formula on to experimental C-V data yields satisfactory results. It is shown that the calculated inductance values of the investigated device range from 10 to 42 μH and after correction, NC values are no longer observed in the C_d-V data.     

SEM investigation of minor constituents of carbide materials prepared from shungite rocks

The “SiC-Al₂OC”-based composite prepared from Karelian shungite rocks has been studied by X-ray diffraction analysis and scanning electron microscopy. SEM investigation has been done to determine the mode and distribution of admixture constituents. It is found that the most common minor phase represents Al–Fe–Si–C-based alloys. Special attention has been given to describing the noble metals admixtures. It is revealed that the noble metals phases occur as separate microsized grains, most of which have been indicated as Au–Ag–Hg amalgam and rarely as Pt-rich compounds. The obtained data can be mainly used to advance technologies for manufacturing carbide-based composite materials from natural carbonaceous rocks.     

Electrical characterization of Au/Pd/n-GaN/Pd/Au device structure in the radio frequency range by simulation study

GaN based devices are highly promising optoelectronic devices for many years due to their useful applications in photovoltaic energy conversation, fiber optic communication and atmosphere monitoring. GaN based devices such as Schottky barrier, metal–semiconductor–metal and p-i-n structure have been fabricated and characterized so far. A proper understanding of the impedance or admittance spectroscopy result is crucial since it is a powerful tool to calculate the physical and electronic parameters of a device. In this study, temperature dependent dark current–voltage (I–V) and dark impedance spectra of n type GaN based metal–semiconductor–metal device have been studied with current–voltage and impedance spectra by simulation. All current–voltage characteristics exhibited good rectification behavior. The forward and reverse bias capacitance–voltage (C–V) characteristics of the Au/Pd/n-GaN/Pd/Au device were simulated at 2 MHz probing frequency. Nyquist plots of simulated device at 295 K are shown that two-barrier heights can be observable above critical threshold bias point. Frequency depended inverse dielectric loss tangent spectra of Au/Pd/n-GaN/Pd/Au device at different DC bias voltages also shows significant two peaks. This indicates that our simulation is extremely useful for determination of potential barrier numbers.