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Open access

P. Jantos, D. Grzechca and J. Rutkowski

Evolutionary algorithms for global parametric fault diagnosis in analogue integrated circuits

An evolutionary method for analogue integrated circuits diagnosis is presented in this paper. The method allows for global parametric faults localization at the prototype stage of life of an analogue integrated circuit. The presented method is based on the circuit under test response base and the advanced features classification. A classifier is built with the use of evolutionary algorithms, such as differential evolution and gene expression programming. As the proposed diagnosis method might be applied at the production phase there is a method for shortening the diagnosis time suggested. An evolutionary approach has been verified with the use of several exemplary circuits - an oscillator, a band-pass filter and two operational amplifiers. A comparison of the presented algorithm and two classical methods - the linear classifier and the nearest neighborhood method - proves that the heuristic approach allows for acquiring significantly better results.

Open access

P.K. Krajewski, G. Piwowarski, J. Buraś, W.K. Krajewski, P. Rutkowski and D. Szeliga

Abstract

The paper brings results of examinations of main thermo-physical properties of selected Inconel alloys, i.e. their heat diffusivity, thermal conductivity and heat capacity, measured in wide temperature range of 20 – 900 oC. Themathematical relationships of the above properties vs. temperature were obtained for the IN 100 and IN 713C alloys. These data can be used when modelling the IN alloys solidification processes aimed at obtaining required structure and properties as well as when designing optimal work temperature parameters.

Open access

Dorota Konopacka, Krzysztof P. Rutkowski, Dorota E. Kruczyńska, Anna Skorupińska and Witold Płocharski

Abstract

The eating quality of nine new pear cultivars grown in Poland was investigated in 2008-2011. Fruits of two summer cultivars: ‘Alfa’ and ‘Radana’, as well as late season varieties: ‘Hortensia’, ‘Dicolor’, ‘Concorde’, ‘Uta’, ‘Xenia’, ‘Erika’ and ‘Verdi’ were compared to fruits of ‘Clapp’s Favorite’ and ‘Conference’, which were taken as cultivars of reference. Fruits of all cultivars were harvested from the Experimental Orchard of the Research Institute of Horticulture at the commercial maturity stage and stored at +2.5 °C or -0.5 °C in a normal atmosphere (NA) or at -0.5 °C in a controlled atmosphere (CA) (0.7% CO2 : 2% O2) for 6 to 16 weeks. At the end of storage, the fruits of each cultivar were subjected to an individual ripening schedule at 18 °C (up to 14 days), which generated samples of diversified quality attributes. Based on instrumental analyses and descriptive sensory assessment the quality attributes of each cultivar were examined. The gathered data on the dynamics of quality attribute changes during the ripening stage confirm that each new cultivar needs an individual strategy during storage and ripening in order to maximise their specific sensory attributes to increase potential market value. The obtained data leads to the conclusion that ‘Xenia’ and ‘Concorde’ fruits have the biggest chance to fulfil consumer expectations, as they were appreciated more than the reference ‘Conference’ cultivar. Among the others also ‘Hortensia’, ‘Verdi’ and ‘Dicolor’ were scored higher than ‘Conference’, but their advantages were not so evident.

Open access

P. Madejczyk, A. Piotrowski, K. Kłos, W. Gawron, A. Rogalski, J. Rutkowski and W. Mróz

Surface smoothness improvement of HgCdTe layers grown by MOCVD

This paper presents results of experimental efforts pointed towards morphology improvement of HgCdTe layers grown by MOCVD on GaAs substrates. Selected growth parameters on morphology state are presented. The substrate issues like its quality and crystallographic orientation have been discussed. Also influence of HgCdTe layer thickness on its surface roughness is described.

It is shown that extensive characterization studies using accessible equipments and methods: atomic force microscopy (AFM), secondary electron microscopy (SEM), laser scatterometer and Nomarski microscopy, have provided invaluable information about the correlation between defect formation and the influence of specific growth parameters.

Open access

J. Huebner, P. Rutkowski, D. Kata and J. Kusiński

Abstract

This study focuses on the investigation of fine (~0.54 μm) tungsten carbide particles effect on structural and mechanical properties of laser cladded Inconel 625-WC composite. Three powder mixtures with different Inconel 625 – WC weight ratio (10, 20 and 30 weight % of WC) were prepared. Coatings were made using following process parameters: laser beam diameter ø ≈ 500 μm, powder feeder rotation speed – 7 m/min, scanning velocity – 10 m/min, laser power – 220 W changed to 320 W, distance between tracks – 1 mm changed to 0.8 mm. Microstructure and hardness were investigated. Coatings produced by laser cladding were crack and pore free, chemically and structurally homogenous. High cooling rate during cladding process resulted in fine microstructure of material. Hardness improved with addition of WC from 396.3 ±10.5 HV for pure Inconel 625, to 469.9 ±24.9 HV for 30 weight % of WC. Tungsten carbide dissolved in Inconel 625 which allowed formation of intergranular eutectic that contains TCP phases.

Open access

M.U. Ahmed, N. Rehman, D. Looney, T.M. Rutkowski and D.P. Mandic

Abstract

Established complexity measures typically operate at a single scale and thus fail to quantify inherent long-range correlations in real-world data, a key feature of complex systems. The recently introduced multiscale entropy (MSE) method has the ability to detect fractal correlations and has been used successfully to assess the complexity of univariate data. However, multivariate observations are common in many real-world scenarios and a simultaneous analysis of their structural complexity is a prerequisite for the understanding of the underlying signal-generating mechanism. For this purpose, based on the notion of multivariate sample entropy, the standard MSE method is extended to the multivariate case, whereby for rigor, the intrinsic multivariate scales of the input data are generated adaptively via the multivariate empirical mode decomposition (MEMD) algorithm. This allows us to gain better understanding of the complexity of the underlying multivariate real-world process, together with more degrees of freedom and physical interpretation in the analysis. Simulations on both synthetic and real-world biological multivariate data sets support the analysis.

Open access

Dorota Konopacka, Urszula Kaczmarek, Aneta Matulska, Anna Wawrzyńczak, Dorota Kruczyńska and Krzysztof P. Rutkowski

Abstract

The aim of the study was to compare the sensory quality of scab resistant ‘Topaz’ apples grown in certified organic orchards (ECO) with those grown in orchards managed within integrated method (IP), and to determine their potential processing suitability. Fruits were harvested in five certificated IP and ECO orchards at the optimum ripeness stage and stored for two months in normal atmosphere at 1 ºC. Apple quality was assessed one day after cold storage and after 7 days of storage at the temperature 18 ºC to simulate shelf life. The results of taste and flavour sensory assessment did not explicitly demonstrate the effect of the orchard management system on the overall eating quality. Although the fruits from the organic orchards were perceived as less sweet and sourer, the management system did not influence the overall eating quality. There was no effect of the growing technology on quality traits connected with aroma and overall texture assessment. Regarding appearance evaluation, fruits from organic orchards were characterized by a higher variation in shape and size, and more frequently than in the case of IP apples had blemishes, scars and rust, which negatively affected their attractiveness. Analysis of the chemical composition of fruits indicates that apples from organic orchards are characterized on average by higher titratable acidity and higher soluble solids content than apples from IP orchards, which could favour their potential application as the additive regulating acidity and shaping the desirable sensory traits of processed organic products.

Open access

Robert Rozwałka, Tomasz Rutkowski and Paweł Bielak -Bielecki

Abstract

In Central Europe, as well as in Poland many introduced spider species have been recorded in the past decades. Most of them are from areas with warm climate, and spreading mainly in synanthropic environment, rarely colonizing natural habitats. Results of research, presented in this paper extend the list of Polish synanthropic araneofauna by four species: Latrodectus mactans, Cheiracanthium mildei, Heteropoda venatoria and Heliophanus cf. apiatus. In addition, new findings of rare or rarely collected synanthropic spider species (Nesticella mogera, Scytodes thoracica, Psilochorus simoni, Uloborus plumipes, Parasteatoda tabulata, Steatoda triangulosa, Mermessus trilobatus, Ostearius melanopygius, Hasarius adansoni, Leptorchestes berolinensis, Pseudeuophrys lanigera) are discussed. Presented data enrich our knowledge about distribution of these species in Poland and show new pathways of potential expansion. For Uloborus plumipes and Hasarius adansoni presence of stable, permanent populations is shown. Findings of Mermessus trilobatus and Ostearius melanopygius in open country suggest that these alien species are gradually colonizing natural biotopes.

Open access

Magdalena Jasińska-Stroschein, Piotr Szcześniak, Jacek Owczarek, Krzysztof P. Rutkowski, Jarosław Markowski, Elżbieta Rozpara and Daria Orszulak-Michalak

Abstract

The allergic reactions to fruits are lesser known among food sensitivities. The most common fruits belonging to the Rosaceae family that might cause allergic reactions are apples, pears and peaches. However, little is known about the potential allergic reactions caused by another member of the Rosaceae, the cherry. The aim of this study was to assess the risk of any allergic reaction or food hypersensitivity resulting from topical application and chronic oral administration of cherry fruits. The cherry fruits ‘Sabina’ cv. were produced in the orchard in Dąbrowice according to the principles of integrated (IFP) and organic (OR) productions. Fruits of ‘Debreceni Bötermö’ cv. were produced in Dąbrowice (IFP), and in the orchard in Nowy Dwór (OR). The experiments were performed on 65 outbred young, adult, white albinotic guinea pigs (Dankin Hartley). Three procedures were applied: I. Guinea-Pig Maximization Test (GPMT); II. Chronic administration of fruits and III. Skin prick (Dreborg) test. The skin reactions based on GPMT or Dreborg tests revealed no differences between the two cherry cultivars ‘Sabina’ and ‘Debreceni’ obtained from integrated or organic production. Similarly, it was not observed of any effect of cultivars of cherries nor the type of fruits production on the guinea pig skin reaction as a result of chronic feeding with fruits.