Evaluation of microbial toxins,trace elements and sensory properties of a high-theabrownins instant Pu-erh tea produced using Aspergillus tubingensis via submerged fermentation

Theabrownins (TB) are polymeric phenolic compounds associated with the multiple bioactivities of Pu-erh tea, a post-fermented Chinese dark tea. High-TB instant Pu-erh tea was produced via a novel submerged fermentation (SF) using Aspergillus tubingensis and compared with samples produced commercially via the conventional solid-state fermentation (SSF). Viable microorganisms and microbial toxins, especially aflatoxins B₁, G₁, B₂, G₂, cyclopiazonic acid, fumonisins B₁, B₂, B₃ and ochratoxin A, were below the detection limit in all samples. Fewer microbial metabolites were found in SF instant tea compared with the SSF teas. Based on an adult consuming 1 g of instant Pu-erh tea daily, the dietary intake of investigated elements was below the safe limits recommended by various authorities. Tasters viewed the instant tea infusions as very mild, smooth, mellow and full. This suggested that submerged fermentation using A. tubingensis offers a speedy and safe alternative to commercial production of instant Pu-erh tea.     

Corrosion behaviour of AA2024 aluminium alloy in different tempers in NaCl solution and with the CeCl3 corrosion inhibitor

The paper analyses the corrosion behaviour of naturally and artificially aged AA2024 alloy in NaCl solution and in the presence of an environment-friendly corrosion inhibitor, CeCl₃. On the basis of the values of polarisation resistance and corrosion current density, the corrosion resistance of the protective inhibitor film is established as well as the general corrosion resistance of this aluminium alloy. Resistance to pit formation is determined based on the difference in pitting and corrosion potentials while resistance to pit growth is determined based on the amount of charge consumed during pit growth. A scanning electron microscope is used to examine the morphology of the pits formed during the pitting corrosion testing, as well as to determine the cerium content on intermetallic particles and the matrix AA2024 alloy. The corrosion behaviour of AA2024 alloy is investigated after different test periods in NaCl solution and in the same solution with the CeCl₃ inhibitor. The corrosion resistance of both tempers of AA2024 alloy is more than one order of magnitude higher in the presence of CeCl₃. An explanation of the observed differences in the corrosion behaviour of the naturally and artificially aged AA2024 alloy is proposed. Different corrosion behaviour of the alloy after different test periods is also explained.     

Anthocyanin composition of the red wine Babić affected by maceration treatment

Identification of anthocyanins in the wine made of the Croatian autochthonous grape variety of Babić (Vitis vinifera L.) was carried out and their profile was determined by means of high-performance liquid chromatography with diode array and mass spectrometric detection. Dependence of anthocyanins content and profile on maceration treatment conditions was investigated. Statistically significant differences of anthocyanins concentration in wines Babić produced by various maceration treatments were confirmed by the use of multivariate analysis of variances. The investigation results indicated that the maceration temperature exerts higher influence on anthocyanins concentration than the duration of maceration. In addition, on the basis of anthocyanin composition and using different multivariate statistical analyses, differentiation of wines Babić according to maceration treatments was procured.     

An algorithm for architecture partitioning in high-speed networks with bursty traffic

This paper analyzes the performance of a switching architecture. The performance measures include the elapsed time of packet transfer and the waiting time to begin transfer. The architecture is partitioned depending on the type of network used and the expected traffic in the network. Every partition has a switch with a buffer that can absorb surges of bursty traffic within the network partition. The buffer size depends on the type of the network and incoming traffic. The partition size depends on the network bandwidth, network traffic, packet size and buffer size. Examples of different networks are used to show the applications of the model. The results show that the elapsed time of packet switch transfer depends exponentially on the number of partitions in the network.     

Polymer cosolvent system

Summary Both preferential adsorption coefficient λ and intrinsic viscosity [η] for poly (di-o-alkylphenyl methacrylates) /Tetrahydrofuran (THF)/water have been determined. The results are discussed in relation to the steric effect of the ortho-substituent groups on the aromatic ring.     

Microstructural and compositional aspects of ZnO-based varistor ceramics prepared by direct mixing of the constituent phases and high-energy milling

ZnO-based varistor samples were prepared by the direct mixing of the constituent phases (DMCP) and sintering at 1100 °C for 2 h. The influence of the starting powder mixture's composition – the amounts of the pre-reacted varistor compounds and their composition – and its preparation, either with or without mechano-chemical activation (MCA), on the microstructure, phase composition and electrical characteristics of the varistor samples was studied. It showed that MCA improved the density and microstructural homogeneity of the varistor samples. MCA strongly affected the grain growth: it enhanced the nucleation of inversion boundaries (IBs) in the ZnO grains and the IBs-induced grain-growth mechanism resulted in uniform grain growth and hence a microstructure with smaller ZnO grains and a narrower grain size distribution. The final phase composition of the samples prepared by the DMCP method mainly depended on the presence of varistor dopants that can prevent the formation of the pyrochlore phase, especially Cr₂O₃, while MCA can affect it mostly by providing a homogeneous distribution of those dopants. The DMCP varistor samples prepared with MCA had much better current–voltage characteristics than the samples of the same composition prepared from unactivated powders.     

An approach to efficient business intelligent system for financial prediction

A concept of business intelligent system for financial prediction is considered in this paper. It provides data needed for fast, precise and good business decision support to all levels of management. The aim of the project is the development of a new online analytical processing oriented on case-based reasoning (CBR) where a previous experience for every new problem is taken into account. Methodological aspects have been tested in practice as a part of the management information system development project of “Novi Sad Fair”. A case study of an improved application of CBR in prediction of future payments is discussed in the paper. This paper is originally presented at The International Conference on Hybrid Information Technology 2006, at the special session on “Intelligent Information Systems for Financial Engineering”, November 2006 in Cheju Island, Korea.     

Residual fracture energy of high-performance and normal concrete subject to high temperatures

Test data on the residual fracture energy of two significantly different concrete types are presented. About 80 beams of high performance basalt concrete and ordinary gravel concrete have been tested in accordance with the RILEM work of fracture method. The beams are heated at 1°C per minute up to a certain maximum temperature and kept at this temperature for 8 hours before cooling them back to room temperature and testing in three-point bending. The tests show that the two concretes behave almost identifical when the fracture energyG _F is considered as a function of maximum temperature. It is found that the damage introduced by a maximum temperature of 300 to 400°C increases the fracture energy by 50% compared with the reference tests at room temperature. A more tortuous crack surface is one plausible explanation for the significant increase inG _F. The article also presents temperature and weight loss recordings from the heating scenarios and finally, the characteristic length and the cohesive tensile softening curve are shown to depend on the maximum temperature. Basically it is demonstrated that the temperature exposure makes the concrete significantly more ductile.

---

Résumé Des données sur l'énergie résiduelle de rupture de deux bétons différents sont présentées. Environ 80 poutres de béton à base de basalte de très haute performance et de béton à base de gravier ordinaire ont été examinées conformément au travaux de la RILEM sur l'énergie de rupture. Les poutres sont chauffées à 1°C par minute jusqu'à une température maximale, puis maintenues à cette température pendant 8 heures avant d'être refroidies de nouveau à la température ambiante. Les poutres sont ensuite testées en flexion (système de flexion en trois points). Les essais prouvent que les deux bétons se comportent d'une manière presque identique quandG _F est considéré comme une fonction de la température maximale. On peut aussi constater que le dommage occasionné par une température maximale de 300 à 400°C augmente l'énergie de rupture de 50% par comparaison aux essais de référence réalisés à la température ambiante. Une surface de rupture plus tortueuse semble être une explication plausible pour l'augmentation significative deG _F. L'article présente également les évolutions de la température et de la perte de poids pour les scénarios de chauffage utilisés. En conclusion, cette étude montre que la longueur caractéristique et la courbe de post pic dépendent de la température maximale. Fondamentalement cela démontre que l'exposition à la température rend le béton sensiblement plus ductile.