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Number of results: 6
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Abstract

The paper presents plant communities from northern Wedel Jarlsberg Land. 55 species of vascular plants were described in this region. Differentiation of plant communities is discussed as controlled by habitat conditions. Plant succession in intramorainal zones of Renardbreen and Scottbreen has been also considered.

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Authors and Affiliations

Anna Rzętkowska
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Abstract

Heating surfaces in power boilers are exposed to very high heat flux. For evaporator protection against overheating, internally helically ribbed tubes are used. The intensification of the heat transfer and the maintenance of the thin water layer in the intercostal space, using ribbed tubes, enables better protection of the power boiler evaporator than smooth pipes. Extended inner surface changes flow and thermal conditions by influencing the linear pressure drop and heat transfer coefficient. This paper presents equations that are used to determine the heat transfer coefficient. The results of total heat transfer, obtained from CFD simulations, for two types of internally ribbed and plain tubes are also presented.

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Authors and Affiliations

Karol Majewski
Sławomir Grądziel
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Abstract

Time-Frequency (t-f) distributions are frequently employed for analysis of new-born EEG signals because of their non-stationary characteristics. Most of the existing time-frequency distributions fail to concentrate energy for a multicomponent signal having multiple directions of energy distribution in the t-f domain. In order to analyse such signals, we propose an Adaptive Directional Time-Frequency Distribution (ADTFD). The ADTFD outperforms other adaptive kernel and fixed kernel TFDs in terms of its ability to achieve high resolution for EEG seizure signals. It is also shown that the ADTFD can be used to define new time-frequency features that can lead to better classification of EEG signals, e.g. the use of the ADTFD leads to 97.5% total accuracy, which is by 2% more than the results achieved by the other methods.

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Authors and Affiliations

Nabeel A. Khan
Sadiq Ali
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Abstract

Biosensors are a crucial part of most of bioanalytical diagnostic devices and systems. Due to semiconductor technologies, a great progress in diminution of costs and miniaturisation as well as an increased reliability of these devices was achieved. Application of

molecular and biological techniques in the detection process has contributed to a real increase in sensitivity, selectivity, the detection limit and the number of analytes to be detected. Different transducers of chemical parameters into electrical output signals are applied in these devices. Electrochemical principles, both potentiometric and amperometric, are opted for due to their simplicity of application and extremely low costs of such biosensors. Ion sensitive field effect transistors (ISFETs) may be easily integrated into the required electronics, resulting in their miniaturisation. Further miniaturisation may be attained by development of miniaturised total analytical systems (uTAS). To ensure competitive parameters of these biosensors, optimal methods of immobilisation of biochemical receptors (ionophores, enzymes, antibodies, etc.) should be developed. A review of the work by the authors related to these problems is presented in the article.

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Authors and Affiliations

D.G. Pijanowska
W. Torbicz
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Abstract

A number of micromechanical investigations have been performed to predict behaviour of composite interfaces, showing that the detailed behaviour of the material at these interfaces frequently dominates the behaviour of the composite as a whole. The interfacial interaction is an extremely complex process due to continuous evolution of interfacial zones during deformation and this is particularly true for carbon nanotubes since the interfacial interaction is confined to the discrete molecular level. The atomic strain concept based upon Voronoi tessellation allows analyzing the molecular structure atom by atom, which may give a unique insight into deformation phenomena operative at molecular level such as interface behaviour in nanocomposites.

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Authors and Affiliations

R. Pyrz
B. Bochenek

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