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Volume 4, Year 2013, Issue 1, January-March

Volume 4, Year 2013, Issue 1, January-March

Cover
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Segmentation Based on Determinate Chaos of Histological Specimen Images
Author:
Valery Orel, Andriy Gusynin, Hanna Selezneva, Serge Kolesnik, Hanna Stendyk, Helen Komisarova
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Abstract: Neuroblastoma is one of the most abundant tumors in infancy and ranks the fourth place among all malignant tumors of children, after acute leukemia, tumors of central nervous system and malignant lymphomas. Histological examination of atypical cell structures is mandatory for diagnosing and forecasting of neoplasm growth .. At present, the image processing of histological specimens is made by a professional histologist manually and is based on visual perception of the histologist. Naturally, visual approach has some shortcomings. Therefore, for objective estimation of medical images, increasing diagnosis accuracy and information processing speed, the computer analysis of histological images is a current need. In this paper, the features of the digital images of histological specimens and methods for digital analysis of medical images are presented. An innovative information system for instant diagnosis of the stage of neuroblastoma based on digital images analysis of histological specimens is developed. In presented studies, a new algorithm, based on deterministic chaos of digital images of histological specimens which uses original formalized indicators (irregularity of contoured zone of diagnostic interest, its structures heterogeneity including cells, nuclei,  itochondrion
etc.) have been implemented.

Keywords: image analysis, segmentation, histological specimen, neuroblastoma

Area: Biomedical Engineering

Electrospinning Production of PLLA Fibrous Scaffolds for Tissue Engineering
Author:
Michał Wojasinski, Krzysztof Faliszewski, Tomasz Ciach
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Abstract: Nonwoven fibrous mats were produced in the process of solution electrospinning. Polymeric fibres generated in this process consist of poly(L-lactic) acid (PLLA), biodegradable and biocompatible polymer. Produced fibrous mats were examined by scanning electron microscopy and additionally degradation rate of fibrous material was investigated. Obtained fibres exhibit porous surface and fibre diameter varied from 200 nm to 1,2 ım, depending on the process parameters. Low degradation rate of scaffold material was designed for long-term scaffold usage. The influence of solvent type and solution concentration as well as the solution flow rate, applied voltage and the setup geometry on the fibres morphology and diameter were examined and presented. The influence of polymer concentration on the solution viscosity was also evaluated. Further, the degradation rate of obtained fibres was investigated, as well as the influence of degradation process on surrounding environment. Materials produced in electrospinning process have potential application as long-term biodegradable scaffold for tissue engineering, especially in bone tissue, vascular tissue or cartilage tissue engineering.

Keywords: nanofibre, electrospinning, poly(L-lactic acid), tissue engineering, biomaterial, degradation

Area: Biomedical Engineering

Aircraft dynamic model identification on the basis of flight data recorder registers
Author:
Maciej Lasek, Piotr Lichota
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Abstract: We investigate the problem of an aircraft dynamic model parametric identification using dimensional derivatives as an example. Identification is done in offline mode, in the time domain. Flight parameters used for identification are obtained from Flight Data Recorder, that register them during each scheduled flight. We investigate the possibility of application of Maximum Likelihood Estimation that belongs to the Output Error Methods class. The likelihood function is defined for n-dimensional multivariate normal distribution. Unknown covariance matrix is estimated with the use of measured data and output equation. Output equation is calculated with Runge–Kutta fourth order method. In order to find the cost function minimum we consider using Levenberg-Marquardt Algorithm, where derivatives are calculated with central difference formulas and small perturbations theory. Mathematical model of an aircraft is obtained through flight dynamics classical approach. Rigid body model of an aircraft is assumed. Coordinate Systems Transformations are done using Euler’s Rotation Theorem with angle order typical for flight dynamics. Equations of motion are obtained from Newtons Second Law of Motion in body fixed coordinate system Oxyz, that is located at aircraft’s center of gravity. Turbulence is modeled as a bias, and also is an object of identification. We implement this method in Matlab R2009b environment.

Keywords: Dimensional derivatives; Estimation; Flight Data Recorder; Flight Dynamics; Maximum Likelihood Estimation; Levenberg-Marquardt; System Identification

Area: Mechanics, Automation and Robotics

Fault-tolerant algorithm for a mobile robot solving a maze
Author:
Adam Srebro
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Abstract: Maze solving problem has been considered since the ancient times. In robotics community this problem is widely known from the ”All Japan Micromouse Competition”. In this paper the author has extended the maze solving problem of cases when some robot distance sensors have been damaged. A new fault-tolerant algorithm for a mobile robot solving a maze is proposed. A dedi - cated simulator has been designed and written in Java to compare several maze solving algorithms for different combination of sensors failures.

Keywords: fault-tolerant, flood fill, maze solving, mobile robot, simulator

Area: Mechanics, Automation and Robotics

Operating properties of photopolymer stamps for hot foil stamping
Author:
Nataliya Yarka, Volodymyr Maik, Valentyna Sysyuk
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Abstract: Hot foil stamping of printed products is very popular in postpress processes. Use of photopolymer materials for stamps producing is a well known process. This work provides operating properties (hardness, deformation and thermophysical properties, wear resistance) research of novel photopolymer materials for direct laser engraving of stamps for hot foil stamping. Research results comparison with requirements to photopolymer materials for printing plates and stamps made it possible to provide a conclusion about suitability of the researched materials for stamps producing.

Keywords: photopolymer stamps, physico-mechanical properties, direct laser engraving

Area: Nanotechnologies and Materials

Influence of Ionic Liquids on growth of Escherichia coli strain possessing β-galactosidase activity
Author:
Magdalena Stobinska, Dawid Urbanski, Artur Bartkowiak
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Abstract: Ionic liquids (ILs) have gained a significant attention as alternative solvents in many chemical and biological reactions. ILs have evolved as a new type of non-aqueous solvents for biocatalysis, because they can stabilize and activate enzymes. Ionic liquids to be considered as so called “green solvents” should possess only very low or no toxicity to living organism and the environment. Currently, very little is known about the biotoxicity of ionic liquids. Within this paper a relative toxicity of two ionic liquids 1,3 dimethylimidazolium methyl sulfate [MMIM][MeSO4] and 1-hexyl-3-methylimidazolium chloride [HMIM][Cl]) on the growth of Escherichia coli (E.coli) was evaluated. In this study we focused on ionic liquids, which potentially could increase activity of β-galactosidase produced by selected strain of E. coli. The inhibition of cell growth in the presence of various ionic liquids was determined using both, solid and liquid cultures. Liquid culture was incubated in culture medium with different concentrations of ionic liquids (0.1, 1, 5, 10% (v/v)). Determination of the minimal inhibitory concentration (MIC50) of ionic liquids was based on monitoring of E. coli growth by optical density measured at 600 nm using densitometer. In the second method the solid culture plate with addition of various amount of ILs has been used. The number of colonies formed on the solid culture plate was converted to colony forming units (CFUs). The obtained results have confirmed, that prescreening based on cytotoxicity tests is a key element in selection procedure of ILs for any biotechnological processes based on application of microorganisms.

Keywords: ionic liquids, β-galactosidase, toxicity

Area: Natural Sciences

Potentiometric detection of the metabolic activity of human tumor cells
Author:
Karina (Ziółkowska) Kwapiszewska, Katarzyna Stepien, Przemysław Sendys, Michał Chudy, Zbigniew Brzózka
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12 x
 

 

Abstract: Monitoring of cellular viability is a key part of toxicological assays in vitro. On-line monitoring of metabolic activity would be particularly useful for evaluation of responses to potential therapeutic compounds. Current assays are mostly based on fluorescent dyes and optical detection methods. These methods offer high sensitivity and specificity, however are not suitable for long-term on-line observations. Electrochemical methods can be an alternative for current protocols. Electrochemical detection is low cost and label-free, therefore suitable for long-term cell culture monitoring. In this work investigations on human cancer cells viability will be presented. Cells were cultured as two-dimensional monolayer or three-dimensional spheroids. Different cell culture media were examined. Potentiometric detection was used for continuous monitoring of cell culture as well as end-point investigations. Different growth phases were identified using applied method. Finally, response to an anticancer drug was successfully observed.

Keywords: cancer, in vitro cell culture, potentiometry, cell culture monitoring

Area: Natural Sciences

Analysis of properties of a laboratory model of a Gamma Stirling engine
Author:
Daniel Fekieta
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16 x
 

 

Abstract: The main subject of the article is the analysis of the characteristics of a Stirling engine. The article presents a general principle of operation of the engine, its basic types and properties. The paper contains a description of the construction of a laboratory model of the engine and the results of the experimental studies. The basic criterion which guided the designing and building the engine was to maximize the energy density, efficiency, while minimizing the cost of materials – to this end the engine has been designed and constructed so as to allow replacement of particular components. The conducted experimental studies have shown that the best parameters of the engine has a cylinder made of iron, a steel flywheel and a steel radiator. The brake efficiency of the engine for this configuration was 16%.

Keywords: Stirling engine, efficiency, mechanical power

Area: Power Engineering

The fire hazard during combustion of some alternative fuels
Author:
Arkadiusz Szydełko, Bartosz Urbanek, Wojciech Moroń
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12 x
 

 

Abstract: Alternative fuels are fuels which include: biomass fuel from waste and sewage sludge. Co-firing biomass with coal is now considered as an effective and financially attractive way the use of biomass for energy production. Perhaps in the future this new technology will replace co-efficient technologies, such as gasification in combination of the gas-steam systems, and the use of gas or ethanol from biomass to value highly efficient fuel cells [1]. The use of coal and biomass mixtures can also be a threat to the safe operation of the plant, including in particular the preparation and installation of the fuel supply. Organic matter in biomass (organic fraction) is a complex mixture of fats, proteins, carbohydrates, humic material-go and fatty acids [2–4]. Self-igniting the fuel can be the result of various factors such as chemical, physical or biological agents stored inside a large amount of organic matter. Self-igniting solid fuels storage depends on many factors such as particle size, nature and type of biomass, coal, the moisture content of the fuel, the storage method and the means of ventilation [5]. In order to determine the self-ignition temperature of coal and of biomass: straw pellets and wood pellets, the method called CPT (Crossing Point Test) [18] was used. Apart from this, the  elemental composition of these biomass as well as of coal have been marked.

Keywords: alternative fuel, biomass, SRF, CPT, fire hazard, self-ignition

Area: Power Engineering

 
 
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