Synthesis and Electrochemical Proprieties of Novel Unsymmetrical Bis-Tetrathiafulvalenes and Electrical Conductivity of Their Charge Transfer Complexes with Tetracyanoquinodimethane (TCNQ)

The synthesis and properties of a series of bis-tetrathiafulvalenes (bis-TTFs) containing nitrophenyl, aminophenyl or dimethylaminophenyl is reported. The synthesis was carried out by using routes involving Wittig-type, cross-coupling, reduction and alkylation reactions. The electron donor ability of these new compounds has been measured by cyclic voltammetry (CV). Charge transfer complexes with tetracyanoquinodimethane (TCNQ) were prepared by chemical redox reactions. The complexes have been proven to give conducting materials.     

Optimization of enzymatic extraction of ferulic acid from wheat bran,using response surface methodology,and characterization of the resulting fractions

BACKGROUND: The agro‐industries generate thousands of tons of by‐products, such as bran or pulps, each year. They are, at best, used for cattle feeding. Through biocracking, this biomass may constitute a renewable source for various molecules of interest for the industry. For instance, ferulic acid, a compound showing antioxidant ability, is found in abundance in cereal bran. Its release depends mainly on the breaking of its ester linkage to other constitutive elements of the cell wall, such as arabinoxylans. Response surface methodology was used to evaluate the effects of ferulic acid esterase (FAE) and xylanase activities, as well as incubation time and temperature, on ferulic acid extraction yield from wheat bran. Under optimized conditions, the composition of the hydrolysate and of residual bran were compared to native bran. RESULTS: Experiments carried out under the predicted optimal conditions (FAE amount, 27 U g^?1; xylanase amount, 304 U g^?1; incubation time, 2 h; and temperature, 65 °C) led to an extraction yield of 52.8%, agreeing with the expected value (51.0%). The crude ferulic acid fraction was purified with Amberlite XAD16, leading to a final concentration of 125 µg mL^?1 of ferulic acid in ethanol. The antioxidant capacity of this purified fraction was evaluated by the DPPH· scavenging method: it exhibited better efficiency (EC₅₀ = 10.6 µmol L^?1 in ferulic acid) than the ferulic acid standard (EC₅₀ = 13.7 µmol L^?1). CONCLUSION: These results confirm the potential of wheat bran valorization in the field of natural antioxidant extraction, possibly viable in an industrial scheme. Copyright © 2009 Society of Chemical Industry     

Study the Heat Recovery Performance of Micro and Nano Metfoam Regenerators in Alpha Type Stirling Engine Conditions

This paper experimentally investigates the performance of micro and nano metfoam regenerators in alpha-type Stirling engine conditions. The thermal efficiency of this engine depends on performance of regenerator. Therefore, increase the heat recovery of regenerator raises the total efficiency. Accordingly, two types of regenerators from porous media are designed and simulated with different materials. Three-dimensional regenerator CFD simulation shows that randomize porous open cell metfoam made of silver as high conductivity and high heat capacity material is the best structure to fabricate metfoam regenerator. The porosity and matrix element diameter are optimized. The nano coating methodology enhances the activated surface. The regenerators are fabricated using casting polymer mold layer deposition. The nano silver particles are coated on the metfoam by sol-gel coating method. Experimental results show the improvement in regenerator percentage of heat recovery by 3.40% and 5.93% for micro metfoam and nano metfoam, respectively. The maximum improvement is achieved up to 8.65% in case of using the nano metfoam regenerator at 543 K.     

Selection and identification of protective culture for controlling Staphylococcus aureus in fresh Domiati like cheese

Antibacterial activity of forty lactic acid bacteria (LAB) isolates toward Staphylococcus aureus was evaluated. The selected strains were then used as protective culture in artificial contaminated Domiati like cheese with S. aureus. The effect of using these strains on physicochemical properties and overall acceptability of fresh cheese was evaluated. Depending on its antibacterial activity, three strains of Lactobacillus rhamnosus 130RZFAAU, 131RZFAAU, and 190RZFAAU were selected for cheese making. No negative sensory properties were observed by the panelists when LAB strains were used as a single culture in the fresh cheese making. The application of these strains as protective culture in artificial contaminated cheesemaking process give a positive results. S. aureus was detected in cheese samples by culture method and propidium mono azide–quantitative polymerase chain reaction method. The results recommended that the strain L. rahmnosus 131RZFAUU that used in this study has antimicrobial activity against S. aureus and could be used as protective culture for improving the safety of Egyptian soft cheese.

Practical applications

Detection of pathogenic bacteria by classical tests can take several days. It would be useful to have a rapid detection protocol to screen for the presence of Staphylococcus aureus in milk and cheese. Application of real‐time PCR in cheese is sufficient in characterization the S. aureus communities in raw milk and follow the dynamics of the entire populations in cheese. Recently, some scientific publications have shown that the naturally cheese microflora can efficiently prevent the growth of pathogenic or spoilage microorganisms. The control of spoilage and pathogens bacteria has been traditionally done by chemical additives, but the application of promising protective cultures, especially for traditionally cheeses made from raw milk, is limited. This work present some protective culture selected for controlling S. aureus in soft cheese. This work confirm the PMA‐q PCR method for detection live cells of S. aureus in cheese rapidly.     

Exponential passivity for output feedback stabilisation of nonlinear uncertain systems

In this article, we address the problem of stabilisation by output feedback for a class of uncertain systems. We consider uncertain systems with a nominal part which is affine in the control and an uncertain part which is norm bounded by a known function. We propose an output feedback such that the closed loop system is globally exponentially stable.     

Une plate-forme de validation multi-protocoles et multi-services Résultats d’expérimentation

This article presents the implementation of a validation platform based on formal methods and the experimental results obtained. This platform allows performing conformance and interoperability tests, analysing the specification and constructing a performance model for the services. It covers all stages of the validation which are: formal specification, test architecture definition, test generation and execution for the defined architecture, and performance evaluation. The test methods and architectures used here make it easier to detect and localise errors. The platform has been constructed within the framework of theRnrt (National Telecommunications Research Network) platform project, platonis. This platform is composed of a network integrating the different sites of the project partners. The principal application domains for the platform are telecommunication systems and mobile telephony. In particular, two different cases study are presented that illustrate the platform’s applicability to the test of mobile 3rd generation protocols and services usingWap, gprs andUmts. Nevertheless, the platform is generic and can be used for other types of communication protocols and services.     

Root-mediated effects in carrot resistance to the carrot fly,Psila rosae

Field experiments on two different soil types in Ireland assessed the extent and mechanisms of resistance toPsila rosae (F.), the carrot fly, with emphasis on the role of the carrot root. Ten carrot cultivars gave consistent results in terms of resistant and susceptible cultivars. Nonpreference oviposition was confirmed as a mechanism, and the use of egg traps, providing differential exposure of the main root, showed this was regulated by root factors, probably chemical constituents. Independent main root resistance to the larva was also confirmed, and this effect was established as consistent with a chemically mediated nonpreference. Antibiosis by the root was demonstrated. Such effects in three different modes indicate that main root properties are crucial in carrot resistance toPsila and suggest a pervasive influence of root chemicals on such resistance.     

Very deep feature extraction and fusion for arrhythmias detection

The electrocardiogram (ECG) is a picture of heart electrical conduction, which is widely used to diagnose many types of diseases such as abnormal heartbeat rhythm (arrhythmia). However, it is very difficult to detect the abnormal ECG characteristics because of the nonlinearity and the complexity of ECG signals from one side, and the noise effect of these signals from the other side, which make it very difficult to perform direct information extraction. Therefore, in this study we propose a very deep convolutional neural network (VDCNN) by using small filters throughout the whole net to reduce the noise affect and improve the performance. Our approach introduces multi-canonical correlation analysis (MCCA), a method to learn selective adaptive layer’s features such that the resulting representations are highly linearly correlated and speed up the training task. Moreover, the Q-Gaussian multi-class support vector machine (QG-MSVM) is introduced for classification, an algorithm which has a better learning performance and generalization ability on ECG signals processing. As a result, we come up with expressively more accurate architecture which is able to differentiate between the normal (NSR) heartbeats and three common types of arrhythmia atrial fibrillation (A-Fib), atrial flutter (AFL), and paroxysmal supraventricular tachycardia (PSVT) without performing any noise filtering or pre-processing techniques. Experimental results show that the proposed algorithm outperforms the state-of-the-art methods.

     

Simulated annealing algorithm for combined economic and emission power dispatch using max/max price penalty factor

A new recurrent neural model for crack growth process of aluminium alloy is developed in this work. It is shown that a recurrent neural network with the feedback loops at the output layer is constructed to model the dynamic relationship between the crack growth and cyclic stress excitations of aluminium alloy. The output feedback loops in the neural model play the role of capturing the fine changes of crack growth dynamics. The Extreme Learning Machine is then used to uniformly randomly assign the input weights in a proper range and globally optimize both the output weights and feedback parameters, to ensure that the dynamics of crack growth under variable-amplitude loading can be accurately modeled. The simulation results with the averaged experimental data of the 2024-T351 aluminium alloy show that the excellent modeling and prediction performance of the recurrent neural model can be achieved for fatigue crack growth of aluminium alloys.