2014 - Repozytorium publikacji - Politechnika Gdańska

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Analysis of transformer state by fuzzy TOPSIS and AHP method
- Mikołaj Bartłomiejczyk
- Miroslav Gutten
- Stefan Hamacek
2014
The paper presents mathematical models TOPSIS and AHP methods, which was utilized on insulating state of distribution transformer to analyze and sensibility of individual measurements methods mutual comparison. We can uniquely determine the importance of these measurements methods with this mathematical apparatus in these measurements methods in insulating state of transformers.
Analytical Expression for the Time-Domain Discrete Green's Function of a Plane Wave Propagating in the 2-D FDTD Grid
- Tomasz Stefański
2014 IEEE Antennas and Wireless Propagation Letters
In this letter, a new closed-form expression for the time-domain discrete Green's function (DGF) of a plane wave propagating in the 2-D finite-difference time-domain (FDTD) grid is derived. For the sake of its verification, the time-domain implementation of the analytic field propagator (AFP) technique was developed for the plane wave injection in 2-D total-field/scattered-field (TFSF) FDTD simulations. Such an implementation of AFP requires computations of time-domain DGF for the plane wave with the use of multiple-precision arithmetic. Then, excitations at the TFSF interface can be computed as a time-domain convolution of a source function with DGF. The developed time-domain implementation of AFP demonstrates the leakage error across the TFSF interface around the numerical noise level that validates the correctness of the DGF derivation.
Analytical method for calculation of heat source temperature drop for the Organic Rankine Cycle application
- Dariusz Mikielewicz
- Jarosław Mikielewicz
2014 Pełny tekst APPLIED THERMAL ENGINEERING
In the paper presented are considerations on the cooperation of the limited capacity heat source with the Organic Rankine Cycle unit. Usually the heat source providing thermal energy to the Organic Rankine Cycle (ORC) may have twofold characteristics. It can be in the form of a single phase fluid, i.e. as hot exhaust gas or hot liquid, or in some cases it may be available as a phase changing fluid, as for example, technological or geothermal steam. Such fluid will be condensed whilst supplying heat to the ORC evaporator. In case of the heat source in the form of a single phase fluid flow its temperature is decreasing in the course of heating of the ORC. In the paper a simple analytical method, based on the energy balance of evaporator, is presented for evaluation of the final temperature of the heat source for ORC installation for two cases, namely single phase fluid and phase changing fluid heat supply. Additionally, the ratio of the heating fluid to the ORC working fluid is presented in function of the minimum temperature difference between the heat source and working fluid.
Analytical method of modelling the geometric system of communication route
- Władysław Koc
2014 Pełny tekst MATHEMATICAL PROBLEMS IN ENGINEERING
The paper presents a new analytical approach to modelling the curvature of a communication route by making use of differential equations. The method makes it possible to identify both linear and nonlinear curvature. It enables us to join curves of the same or opposite signs of curvature. Solutions of problems for linear change of curvature and selected variants of nonlinear curvature in polynomial and trigonometric form were analyzed. A comparison of determined horizontal transition curves was made and examples of negotiating these curves into a geometric system were given.
Analytical Modelling of the Multicell Piezoelectric Motor Based on Three Resonance Actuators
- Roland Ryndzionek
- Michał Michna
- Mieczysław Ronkowski
- Jean-Francois Rouchon
2014 Pełny tekst
This paper presents analytical model of the multicell piezoelectric motor. The results, obtained in the field of piezoelectric motors, have pointed out that these motors have potentially high possibilities in the future of special applications. The studied multicell piezoelectric motor have a stator using three rotating mode actuators. A theoretical analysis of operating principle of the rotating mode motor has been described. Additionally the stator/rotor friction contact has been considered. Using the analytical model some electromechanical characteristics of the considered multicell piezoelectric motor have been computed. Finally, computed and measured characteristics have been compared
Anatomy of noise in quantitative biological Raman spectroscopy
- Janusz Smulko
- Narahara Chari Dingari
- Jaqueline S. Soares
- Ishan Barman
2014 Pełny tekst BIOANALYSIS
Raman spectroscopy is a fundamental form of molecular spectroscopy that is widely used to investigate structures and properties of molecules using their vibrational transitions. It relies on inelastic scattering of monochromatic laser light irradiating the specimen. After appropriate filtering the scattered light is dispersed onto a detector to determine the shift from the excitation wavelength, which appears in the form of characteristic spectral patterns. The technique can investigate biological samples and provide real-time diagnosis of diseases. However, despite its intrinsic advantages of specificity and minimal perturbation, the Raman scattered light is typically very weak and limits applications of Raman spectroscopy due to measurement (im)precision, driven by inherent noise in the acquired spectra. In this article, we review the principal noise sources that impact quantitative biological Raman spectroscopy. Further, we discuss how such noise effects can be reduced by innovative changes in the constructed Raman system and appropriate signal processing methods.
Annual changes of basic parameters of bottom sediments from the Klodnica River Catchment
- Ewa Olkowska
- Marek Ruman
- Żaneta Polkowska
2014
The Klodnica River Catchment is heavily contaminated ecosystem located in area of the Upper Silesia Industrial Region. In this area various forms of human activity can be observed (e.g. mining coal underground, metallurgy, power/heat plants, wastewater discharged directly into the river). The impact of industrial and municipal wastes on this aquatic system causes to changes in the hydrographic network of river and the waters quality. In present study, the annual changes of basic physicochemical parameters (pH, electrical conductivity, inorganic ions, different type of organic compounds e.g. cationic surfactants) of bottom sediments collected in area of the Klodnica River Catchment were investigated. These research aims can provide the knowledge to expand areas of research in order to protect abiotic and biotic elements of the environment and the possibility of using them in a sustainable manner.
Annual signals observed in regional GPS networks
- Janusz Bogusz
- Mariusz Figurski
2014 Pełny tekst Acta Geodynamica et Geomaterialia
Abstract: This paper describes analyses concerning annual signals in GPS-derived coordinates. The data was processed in the Military University of Technology Local Analysis Centre with Bernese 5.0 software. We used observations from 129 permanent GPS stations which belong to the Polish Active Geodetic Network (ASG-EUPOS), for the period of GPS weeks 1465-1729, corresponding to about 5 years. The annual signals have been estimated using the Least Squares Estimation (LSE) with assumption of stationarity of amplitude and phase, and uncertainties calculated with the coloured noise assumption using the First Order Gauss Markov model (FOGM). The phase was defined as the time span from the beginning of the year to the maximum of the best-fitting sinusoid. The data was analysed using the TSView software (Herring, 2003). Amplitudes of best-fitting sinusoids into the North components range between 0.1 and 3.5 mm, the East component: 0.1-4.1 mm, the Up component: 0.1-4.0 mm with similar uncertainties of 0.1-0.3 mm. The phase shifts are unevenly distributed over the considered area, no clearly visible spatial dependencies were discovered. The North and East components reveal clearly maximums concentrated over winter- (January and February) and summer-time (June-July). They could be explained by the hydrological and atmospheric (including thermal) influences. However, this theory does not seem to be supported by the Up distribution with no clearly visible extreme values. We noticed that the velocity bias due to annual oscillation could range from –0.6 to +0.5 mm/y, but when we look at the issue relatively we can mismodel the North and East velocity by 3.4 % (0.5 of 14.8 mm/y), while the Up velocity at the tectonically stable areas considered in this publication could be mismodelled by even 600 % (0.6 of 0.1 mm/y). But the annual signal in the GPS time series has to be understood twofold:
Anthropopressure’s intensification with reference to Arctic ecosystems
- Katarzyna Kozak
- Małgorzata Szopińska
- Aneta Pacyna-Kuchta
- Krystyna Kozioł
- Sara Lehmann-Konera
- Żaneta Polkowska
2014
This paper concerns issue of long range atmospheric transport of pollutants to polar areas and intensification of their toxic effect on biota in the face of climate change. Arctic which was for years seen as a pristine and not affected by antropopressure region became a sink of xenobiotics. Atmospheric circulation facilitates transport of chemicals from Eurasia to Arctic. Influence of climate change on crucial balance of polar environment and presence of xenobiotics in polar areas are discussed.
Antibiotic resistance in Staphylococcus aureus strains isolated from cows with mastitis in the eastern Poland and analysis of susceptibility of resistant strains to alternative non-antibiotic agents: lysostaphin, nisin and polymyxin B.
- Piotr Szweda
- Marta Schielmann
- Aneta Frankowska
- Barbara Kot
- Magdalena Zalewska
2014 Pełny tekst JOURNAL OF VETERINARY MEDICAL SCIENCE
The aim of the studies was analysis of resistance of Staphylococcus aureus isolates from bovine mastitis in eastern part of Poland to a set of 20 antibiotics and three alternative agents: lysostaphin, nisin and polymyxin B. Eighty-six out of 123 examined isolates were susceptible to all of 20 tested antibiotics (70 %). The highest percentage of resistance was observed in the case of β-lactam antibiotics: amoxicillin (n=22, 17.9 %), ampicillin (n=28, 22.8 %) and penicillin (n=29, 23.6 %) and streptomycin (n=13; 10.6 %). Twenty-five out of penicillin resistant strains were found to carry blaZ gene coding for β-lactamases. Two strains were found to be mecA positive and few strains were classified as Multi Drug Resistant (MDR), one of them was simultaneously resistant to six antibiotics. All strains, resistant to at least one antibiotic (n=37) and two control strains, were susceptible to lysostaphin with MIC values of: 0.008 – 0.5 μg/ml (susceptible breakpoint 32 μg/ml). Twenty-one (54 %) isolates were susceptible to nisin. The MIC value of this agent for 17 (44 %) strains was 51.2 μg/ml and was not much higher than susceptibility breakpoint value (32 μg/ml). The polymyxin B was able to inhibit the growth of most of strains tested (n=31, 77.5 %) in the concentration of 64 μg/ml, for six isolates the MIC value of this agent was 32 μg/ml and two strains required higher concentration. The presented results confirmed observed worldwide problem of spreading antibiotic resistance among staphylococci isolated from bovine mastitis, on the other hand, we have indicated high level of bactericidal activity of nisin and especially lysostaphin.
Antioxidants: a premature scientific hypothesis that reshuffled the traditional food pyramid
- Agnieszka Bartoszek-Pączkowska
2014
Antioxidants present in substantial amounts in foods, plant-based products in particular, have been suggested as chemopreventive agents that can curb the development of undesirable health effects caused by oxidative stress simply by enriching diet in such compounds. This idea has been enthusiastically accepted by consumers, as well as food and pharmaceutical industry, and created great demand for products containing antioxidant phytochemicals. However, human studies failed to confirm benefits of supplementation with antioxidant nutrients. The chapter discusses possible oversimplifications in understanding the biological role of reactive oxygen species with emphasis on the chemistry behind presumed protective action of antioxidants.
Antitumor 1-nitroacridine derivative C-1748 induces significant apoptosis in pancreatic cancer cells.
- Barbara Borowa-Mazgaj
- Ewa Augustin
- Zofia Mazerska
- Jerzy Konopa
2014 Acta Biochimica Polonica
Pancreatic cancer is the fifth leading cause of cancer death and has the lowest survival rate of any solid cancer in the industrial countries. The poor prognosis of pancreatic cancer results from its tendency for late presentation, aggressive invasion, early metastasis, and resistance to chemotherapy. Gemcitabine still remains the best chemotherapeutic agent available for the treatment of advanced pancreatic cancer. However, gemcitabine treatment results in only a marginal survival advantage. Thus there is a strong need for the continual development of novel therapeutic agents to improve pancreatic cancer therapy. The compound C-1748 is the most active derivative of 1-nitroacridine antitumor agents developed in our laboratory. Strong cytotoxic activity against colon cancer cell lines (HCT8 and HT29) and high antitumour activity against xenografts in nude mice of prostate (LnCaP) and colon carcinoma (HCT8), along with low mutagenic potential and slight myelosuppressive properties allowed the selection of C-1748 for phase I clinical trials.The aim of the current study was to investigate and characterize the cellular response of human pancreatic cancer cell line MiaPaca-2 to C-1748 treatment. This cell line was selected due to its high sensitivity to C-1748. Cell cycle analysis revealed that between 24 h and 48 h of C-1748 treatment, MiaPaca-2 cells underwent transient accumulation in the G2/M phase which was followed by prolonged arrest in the G1 phase. Starting from 96 h of drug exposure, decrease in G1 phase population was accompanied by progressive increase in sub-G1 fraction, suggesting that initial G1 arrest led to cell death through apoptosis. Morphological changes of MiaPaca-2 cells in response to C-1748 treatment were observed using fluorescent microscopy. DAPI staining revealed that cells exposed to C-1748 exhibited features characteristic for apoptosis: condensed chromatin and apoptosis-body like structures. The drug induced apoptosis in time- and dose-dependent manner was also confirmed by flow cytometry analysis. Caspase-3 activation, phosphatydylserine externalization and mitochondrial dysfunction typical for apoptosis were detectable already after 24 h of treatment. To sum up, major cellular response triggered by C-1748 in MiaPaca-2 cells was the effective induction of apoptosis. These results highlight the therapeutic potential of C-1748 in pancreatic cancer and support rationale for its further investigation towards this type of malignancy.
ANYTIME POLYNOMIAL HEURISTIC ALGORITHM FOR PARTITIONING GROUPS OF DATA WITH PRESERVING CLASS PROPORTIONS FOR CROSS-VALIDATION
- Jan Cychnerski
2014
The article describes a problem of splitting data for k-fold cross-validation, where class proportions must be preserved, with additional constraint that data is divided into groups that cannot be split into different cross-validation sets. This problem often occurs in e.g. medical data processing, where data samples from one patient must be included in the same cross-validation set. As this problem is NP-complete, a heuristic anytime polynomial algorithm is proposed and described in the article. Also, it is experimentally compared to two other, simpler algorithms.
APLIKACJA MARKOWSKIEGO MODELU NIEZAWODNOŚCIOW EGO UKŁADU TŁOKOWO – KORBOWEGO SILNIKA SPALINOWEGO Z ZAPŁONEM SAMOCZYNNYM
- Jacek Rudnicki
2014
Prognozowanie niezawodności okrętowych silników spalinowych jest szczególnie istotnym problemem. Pozwala bowiem na przewidywanie stanów niezawodnościowych w przyszłości na podstawie informacji o tych stanach w przeszłości. Trafne prognozowanie niezawodności, to złożony proces przetwarzania empirycznych wyników badań uzyskanych w praktyce eksploatacyjnej, uzupełniony rozważaniami analitycznymi. Proces zmian stanu technicznego każdego silnika jest stochastyczny, ciągły w stanach i w czasie. Zachodzi zatem potrzeba podziału tego nieskończonego zbioru stanów silnika na skończoną liczbę podzbiorów (klas), możliwych do wyraźnej ale i permanentnej identyfikacji za pomocą funkcjonującego systemu diagnozującego. W referacie przedstawiono propozycję modelu matematycznego, który z jednej strony umożliwia uwzględnienie losowości zjawisk wymuszających uszkodzenia, z drugiej zaś prezentuje dosyć istotną elastyczność aplikacyjną
Apparent Molar Volumes and Expansivities of Ionic Liquids Based on N-Alkyl-N-methylmorpholinium Cations in Acetonitrile
- Łukasz Marcinkowski
- Teresa Olszewska
- Adam Kloskowski
- Dorota Warmińska
2014 JOURNAL OF CHEMICAL AND ENGINEERING DATA
Densities of some acetonitrile solutions of ionic liquids based on N-alkyl-N-methyl-morpholinium cations, N-ethyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-butyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide, N-methyl-N-octylmorpholinium bis(trifluoromethanesulfonyl)imide and N-decyl-N-methylmorpholinium bis(trifluoromethanesulfonyl)imide were measured at T = (298.15− 318.15) K and at atmospheric pressure. From density data the apparent molar volumes and partial molar volumes of the ILs at infinite dilution as well as the limiting apparent molar expansibilities and the Hepler’s constant values have been evaluated. The results have been discussed in terms of the effect that alkyl chain length of the ILs and experimental temperature have on the ionic liquid−acetonitrile interactions occurring in the studied solutions.
Applicability of null-steering for spoofing mitigation in civilian GPS
- Jarosław Magiera
- Ryszard Katulski
2014
Civilian GPS signals are currently used in many critical applications, such as precise timing for power grids and telecommunication networks. Spoofing may cause their improper functioning. It is a threat which emerges with the growing availability of GPS constellation simulators and other devices which may be used to perform such attack. Development of the effective countermeasures, covering detection and mitigation, is necessary to provide the appropriate level of protection. In this article the authors present a GPS spoofing mitigation method which uses spatial filtering (null-steering) for excision of undesired signals. The performance of this method is analyzed in various conditions. The attenuation of undesired signals, in presence of noise, is estimated. Furthermore, the statistical analysis of the influence of spatial filtering on the availability of true signals is provided.
Application of an Electronic Nose Instrument to Fast Classification of Polish Honey Types
- Tomasz Dymerski
- Jacek Gębicki
- Waldemar Wardencki
- Jacek Namieśnik
2014 Pełny tekst SENSORS
The paper presents practical utilization of an electronic nose prototype, based on the FIGARO semiconductor sensors, in fast classification of Polish honey types—acacia flower, linden flower, rape, buckwheat and honeydew ones. A set of thermostating modules of the prototype provided gradient temperature characteristics of barbotage-prepared gas mixtures and stable measurement conditions. Three chemometric data analysis methods were employed for the honey samples classification: principal component analysis (PCA), linear discriminant analysis (LDA) and cluster analysis (CA) with the furthest neighbour method. The investigation confirmed usefulness of this type of instrument in correct classification of all aforementioned honey types. In order to provide optimum measurement conditions during honey samples classification the following parameters were selected: volumetric flow rate of carrier gas—15 L/h, barbotage temperature—35 °C, time of sensor signal acquisition since barbotage process onset—60 s. Chemometric analysis allowed discrimination of three honey types using PCA and CA and all five honey types with LDA. The reproducibility of 96% of the results was within the range 4.9%–8.6% CV.
Application of atmospheric pressure microwave plasma source for hydrogen production from ethanol
- Bartosz Hrycak
- Dariusz Czylkowski
- Robert Miotk
- Mirosław Dors
- Mariusz Jasiński
- Jerzy Mizeraczyk
2014 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
In contrast to conventional technologies of hydrogen production like water electrolysis or coal gasification we propose a method based on the atmospheric pressure microwave plasma. In this paper we present results of the experimental investigations of the hydrogen production from ethanol in the atmospheric pressure plasma generated in waveguidesupplied cylindrical type nozzleless microwave (915 MHz and 2.45 GHz) plasma source (MPS). Argon, nitrogen and carbon dioxide were used as a working gas. All experimental tests were performed with the working gas flow rate Q ranged from 1500 to 3900 NL/h and absorbed microwave power PA up to 6 kW. Ethanol was introduced into the plasma as vapours carried with the working gas. The process resulted in the ethanol conversion rate greater than 99%. The hydrogen production rate was up to 210 NL[H2]/h and the energy efficiency was 77 NL[H2] per kWh of absorbed microwave energy.
APPLICATION OF BINARY-ENCOUNTER-BETHE METHOD TO ELECTRON-IMPACT IONIZATION CROSS SECTION CALCULATIONS FOR BIOLOGICALLY RELEVANT MOLECULES
- Bożena Żywicka
- Paweł Możejko
2014
Electron-impact cross sections for platinum chemotherapeutic compounds, purine and pyrimidine molecules calculated using binary-encounterBethe model are presented as examples of possible applications of that method.
Application of composite indicators and nonparametric methods to evaluate and improve the efficiency of the technical universities
- Andrzej Szuwarzyński
- Bartosz Paweł Julkowski
2014 Edukacja
Publicly funded universities, like commercial organizations are obliged to ensure their efficiency. This article presents a model to measure and assess the relative efficiency of technical universities. The analysis was performed using publically available data from 2011 for 18 universities using the Composite Indicators method and the SBM Data Envelopment Analysis model. Fourteen indicators for efficiency were defined in the five areas of the university performance: research, teaching, scientific staff development, quality of teaching processes and public funding. Inefficient units were identified, based on their calculated efficiency scores and the directions for change to allow them to reach greater efficiency were suggested. Methods used to assess efficiency allowed the combined effect of all relevant factors to be taken into account which described the basic operations of the university. Ukazaja się również polska wersja artykułu : http://www.edukacja.ibe.edu.pl/images/numery/2014/3-4-szuwarzynski-julkowski-wykorzystanie-wskaznikow-zlozonych.pdf