Publications Repository - Gdańsk University of Technology

Page settings

polski
Publications Repository
Gdańsk University of Technology

Show publications from the year

Publications from the year 2015

Show all
  • Measurements of fundamental properties of homogeneous tissue phantoms
    • Maciej Wróbel
    • Alexey Popov
    • Alexander Bykov
    • Matti T. Kinnunen
    • Małgorzata Szczerska
    • Valery Tuchin
    2015 Full text JOURNAL OF BIOMEDICAL OPTICS

    We present the optical measurement techniques used in human skin phantom studies. Their accuracy and the sources of errors in microscopic parameters’ estimation of the produced phantoms are described. We have produced optical phantoms for the purpose of simulating human skin tissue at the wavelength of 930 nm. Optical coherence tomography was used to measure the thickness and surface roughness and to detect the internal inhomogeneities. A more detailed study of phantom surface roughness was carried out with the optical profilometer. Reflectance, transmittance, and collimated transmittance of phantoms were measured using an integrating-sphere spectrometer setup. The scattering and absorption coefficients were calculated with the inverse adding-doubling method. The reduced scattering coefficient at 930 nm was found to be 1.57 0.14 mm−1 and the absorption was 0.22 0.03 mm−1. The retrieved optical properties of phantoms are in agreement with the data found in the literature for real human tissues.

  • Measurements of Path Loss in Off-Body Channels in Indoor Environments
    • Sławomir Ambroziak
    • Luis M. Correia
    • Ryszard Katulski
    • Michał Maćkowiak
    2015

    The main goal of the paper is to investigate the influence of body orientation and on-body antenna placement on the path loss in off-body communications. In addition, the influence of different bodies is analysed.

  • Measurements of relative frequency instability
    • Dariusz Świsulski
    2015 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Frequency constancy can be determined by the change in time for the subsequent periods. The article shows that classical the method of digital period measurement is not suitable for the measurement process. Therefore, a method using an integrating circuit is being proposed. Errors in the measurement of the given method have been analyzed.

  • Measures of region failure survivability for wireless mesh networks
    • Jacek Rak
    2015 Full text WIRELESS NETWORKS

    Wireless mesh networks (WMNs) are considered as a promising alternative to wired local, or metropolitan area networks. However, owing to their exposure to various disruptive events, including natural disasters, or human threats, many WMN network elements located close to the failure epicentre are frequently in danger of a simultaneous failure, referred to as a region failure. Therefore, network survivability, being the ability to provide the continuous transmission after a failure, is of great importance. In this paper, we define three new measures of wireless mesh networks survivability for a region failure scenario, including the region failure survivability function, p-fractile region survivability function, and the expected percentage of total flow delivered after a failure as a function of region radius r. These measures are next used to evaluate the vulnerability of example wireless mesh networks to region failures.

  • Measuring and Analyzing Audio Levels in Film, Commercials, and Movie Trailers Using Leq(A) Values and the LUFS Loudness Model . Analiza pomiarów dźwięku w filmie oraz w reklamach filmowych z wykorzystaniem modelu głośności
    • Bożena Kostek
    • Kamila Milarska
    • Aleksander Zakrzewski
    2015

    The purpose of this paper is to describe the measurement of loudness levels in movies, movie trailers, and commercials displayed before feature films at movie theaters. In the initial section, the paper discusses the issues related to measurement of loudness levels, provides recommendations regarding permissible loudness levels during movie screenings, and mentions the applied units of measurement. The following section of the paper describes the actual measurements, measuring equipment, as well as analysis of the results of the measurements. The summary provides conclusions about the measured loudness levels at movie theaters, for DVD and Blu ray discs, and for YouTube videos.

  • Mebel jako integralny element obiektu architektonicznego
    • Agnieszka Kurkowska
    2015 Full text

    Projektant mebli, będąc architektem, może swobodnie obrać właściwą mu strategię pracy, czyli stawiać meble w roli elementów organizujących przestrzeń, przekazujących treść, współdecydujących o odczuciach i doznaniach użytkowników i odbiorców. Dlatego zaprezentowany i przeanalizowany został sposób ‘meblowania przestrzeni’ rozumiany jako jej doposażanie obiektami spoza struktury architektonicznej zaprojektowanymi jednak jako integralne elementy obiektu. Takie rozumienie mebla pozwala rozpatrywać go w kategoriach przedmiotu wielofunkcyjnego. Spełniając, poza funkcją podstawową, jednocześnie rolę podmiotu sytuacji przestrzennej lub związanego z nią ‘wydarzenia’, ustanowienia granicy, może jednocześnie stanowić obiekt sztuki, zgodnie z zamysłem i talentem twórcy.

  • Mechanical Properties of Polyester Coated Fabric Subjected to Biaxial Loading
    • Andrzej Ambroziak
    2015 JOURNAL OF MATERIALS IN CIVIL ENGINEERING

    The paper is focused on the comparison between uniaxial and biaxial laboratory test results for polyester coated fabric. A short literature review concerning coated woven fabrics with emphasis on biaxial tensile tests is presented. A description of the polyester-coated fabric under biaxial test by means of constitutive models and material parameter values is proposed. To establish the right values of the ultimate tensile strength, flat and curved grips are tested.

  • Mechanical properties of Precontraint 1202S coated fabric under biaxial tensile test with different load ratios
    • Andrzej Ambroziak
    2015 CONSTRUCTION AND BUILDING MATERIALS

    The paper describes a method of laboratory tests necessary for identifying the mechanical properties of polyester coated fabrics named Precontraint 1202S with PVDF surface treatment. Two sets of initial material parameters for dense net model and orthotropic model are specified. Material parameters for Precontraint 1202S coated fabric are specified on the basis of the biaxial tensile tests for different load ratios. In order to observe a change of initial mechanical properties, the biaxial cyclic tests are carried out. Additionally, a short survey of literature concerning the coated woven fabrics description and numerical simulations is presented. This paper is also proposed as an introduction to the comprehensive investigation of the mechanical properties of coated woven fabrics.

  • Mechanical properties of PVDF-coated fabric under tensile tests
    • Andrzej Ambroziak
    2015 JOURNAL OF POLYMER ENGINEERING

    This article describes the laboratory tests necessary to identify the mechanical properties of the polyvinylidene fluoride (PVDF)-coated fabrics named Precontraint 1202S and Precontraint 1302S. First, a short survey of the literature concerning the description of coated woven fabrics is presented. Second, the material parameters for PVDF-coated fabrics are specified on the basis of biaxial tensile tests. A comparison of the 1:1 biaxial and the uniaxial tensile tests results is also given. Additionally, biaxial cyclic tests were performed to observe the change of immediate mechanical properties under cyclic load. The article is aimed as an introduction to a comprehensive investigation of the mechanical properties of coated fabrics

  • Mechanical Strength of MV Ship-switchgear During Fault Arc
    • Roman Partyka
    • Daniel Kowalak
    2015 Full text Acta Energetica

    In the paper the analysis of pressure stressed in enclosure during fault arc inside switchgear is pre-sented as well. There is introduced the method based on determining stresses which are sum of tensile stresses (membrane) and deflection stresses. For tensile stresses nalysis the energy method, for unrestrainedly supported rectangular plate, was used. In the further part of the paper, the calculations and measurements results of enclosure stresses were shown. Dimensions of analyzed enclosure were 0,48 x 0,52 m. Also oscillogram record from laboratory tests was given in further part of the paper. There were demonstrated the results of calculations of maximum stresses in enclosure of analyzed cable compartment of marine switchgear during fault arc. In the presented paper the calculation method of pressure and temperature of gases inside MV marine switchgear during fault arc was presented. Simultaneous equation (1) gives thermodynamic model of processes concurrent to fault arcs inside air insulated switchgear. Simultaneous equation (1) enables calculation of pressure and temperature based on average arc power. Above mentioned model is particularly useful for analysis of pressure and temperature in switchgears equipped with slots or overpressure reducing canals. Calculated, according to (1), temperature is average temperature in area encompassed by fault arc. Formulating it more strictly; that area is defined by product of volume V and coefficient c. The method does not count a spatiotemporal distributions of temperature and pressure in total volume of the compartment.

  • Mechanika ogólna : Rozwiązywanie zagadnień z MATHCAD-em
    • Tomasz Kucharski
    2015

    W książce zaprezentowano nową metodę studiowania mechaniki, umożliwiającą kształtowanie intuicji inżynierskiej. W tym celu wykorzystano program MATHCAD, który usprawnia żmudne obliczenia i pozwala zaoszczędzić czas na dokładną analizę rozważanych zjawisk oraz otrzymanych wyników. Książka polecana studentom na zajęcia z mechaniki ogólnej oraz jako praktyczną pomoc przy wykonywaniu prac dyplomowych, a także inżynierom szukającym rozwiązań ułatwiających opracowywanie dokumentacji projektowej.

  • Mechanisms of azole resistance among clinical isolates of Candida glabrata in Poland
    • Piotr Szweda
    • Katarzyna Magdalena Gucwa
    • Ewa Romanowska
    • Katarzyna Dzierżanowska-Fangrat
    • Łukasz Naumiuk
    • Anna Brillowska-Dąbrowska
    • Iwona Wojciechowska-Koszko
    • Sławomir Milewski
    2015 Full text JOURNAL OF MEDICAL MICROBIOLOGY

    Candida glabrata is currently ranked as the second most frequently isolated aetiological agent of human fungal infections, next only to Candida albicans. In comparison with C. albicans, C. glabrata shows lower susceptibility to azoles, the most common agents used in treatment of fungal infections. Interestingly, the mechanisms of resistance to azole agents in C. albicans have been much better investigated than those in C. glabrata. The aim of the presented study was to determine the mechanisms of resistance to azoles in 81 C. glabrata clinical isolates from three different hospitals in Poland. The investigation was carried out with a Sensititre Yeast One test and revealed that 18 strains were resistant to fluconazole, and 15 were cross-resistant to all other azoles tested (voriconazole, posaconazole and itraconazole). One isolate resistant to fluconazole was cross-resistant to voriconazole, and resistance to voriconazole only was observed in six other isolates. All strains were found to be susceptible to echinocandins and amphotericin B, and five were classified as resistant to 5-fluorocytosine. The sequence of the ERG11 gene encoding lanosterol 14-a demethylase (the molecular target of azoles) of 41 isolates, including all strains resistant to fluconazole and three resistant only to voriconazole, was determined, and no amino acid substitutions were found. Real-time PCR studies revealed that 13 of 15 azole-resistant strains showed upregulation of the CDR1 gene encoding the efflux pump. No upregulation of expression of the CDR2 or ERG11 gene was observed.

  • Mechanisms of Damage to DNA Labeled with Electrophilic Nucleobases Induced by Ionizing or UV Radiation
    • Janusz Rak
    • Lidia Chomicz-Mańka
    • Justyna Wiczk
    • Kinga Westphal
    • Magdalena Zdrowowicz
    • Paweł Wityk
    • Michał Żyndul
    • Samanta Makurat
    • Łukasz Golon
    2015 JOURNAL OF PHYSICAL CHEMISTRY B

    Hypoxia—a hallmark of solid tumors—makes hypoxic cells radioresistant. On the other hand, DNA, the main target of anticancer therapy, is not sensitive to the near UV photons and hydrated electrons, one of the major products of water radiolysis under hypoxic conditions. A possible way to overcome these obstacles to the efficient radio- and photodynamic therapy of cancer is to sensitize the cellular DNA to electrons and/or ultraviolet radiation. While incorporated into genomic DNA, modified nucleosides, 5-bromo-2′-deoxyuridine in particular, sensitize cells to both near-ultraviolet photons and γ rays. It is believed that, in both sensitization modes, the reactive nucleobase radical is formed as a primary product which swiftly stabilizes, leading to serious DNA damage, like strand breaks or cross-links. However, despite the apparent similarity, such radio- and photosensitization of DNA seems to be ruled by fundamentally different mechanisms. In this review, we demonstrate that the most important factors deciding on radiodamage to the labeled DNA are (i) the electron affinity (EA) of modified nucleoside (mNZ), (ii) the local surroundings of the label that significantly influences the EA of mNZ, and (iii) the strength of the chemical bond holding together the substituent and a nucleobase. On the other hand, we show that the UV damage to sensitized DNA is governed by long-range photoinduced electron transfer, the efficiency of which is controlled by local DNA sequences. A critical review of the literature mechanisms concerning both types of damage to the labeled biopolymer is presented. Ultimately, the perspectives of studies on DNA sensitization in the context of cancer therapy are discussed.

  • Mechanizmy zmian klimatu atmosfery - problem współczesnego ocieplenia
    • Anna Styszyńska
    • Andrzej Marsz
    2015

    W pracy omawia się rozmiary i rozkład przestrzenny zmian temperatury powietrza na Ziemi w latach 1880-2014, przebieg zmian temperatury powietrza w ostatnim 1000.leciu, poglądy na naturalne przyczyny wzrostu temperatury i oceaniczną kontrolę klimatu atmosfery zwracając uwagę na niezrównoważenie bilansu cieplnego Ziemi w cyklu rocznym oraz akumulację ciepła w oceanie. Zwraca się uwagę na rolę Multidekadowej Oscylacji Atlantyku w zmianach klimatu. Stwierdza się, że zmienność cyrkulacji termohalinowej jest zasadniczą przyczyną obserwowanego obecnie wzrostu temperatury powietrza.

  • Mechatronic design o strongly nonlinear systems on a basis of three wheeled mobile platform
    • Krzysztof Jan Kaliński
    • Cezary Buchholz
    2015 MECHANICAL SYSTEMS AND SIGNAL PROCESSING

    Remarkable grow in demand both of mobile platform operability performance and reduction of project leading time development encourage to apply modern algorithms and reliable engineering tools for the design process. The paper discusses the mechatronic design applied for the surveillance system based on the energy performance index algorithm. The exploited mechatronic techniques i.e. virtual prototyping, Hardware-In-the-Loop Simulation (HILS) and rapid prototyping on target object, supported by the LabVIEW, allowed for integration of the developed control system and strongly nonlinear mobile platform, built simultaneously for the research purposes. Mathematical complexity of on-line algorithm and sophisticated model description affected all the process design. In order to boost mobile platform performance and handle its real time motion surveillance the authors implemented the Real Time controller. The presented design approach allowed authors to achieve the highest level of a mobile platform performance and increased probability of the final concept success.

  • MECONIUM SAMPLES USED TO ASSESS INFANT EXPOSURE TO THE COMPONENTS OF ETS DURING PREGNANCY
    • Sylwia Narkowicz
    • Żaneta Polkowska
    • Bogumiła Kiełbratowska
    • Jacek Namieśnik
    2015 Full text INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH

    The aim of the study was to use meconium samples to assess fetal exposure to compounds present in environmental tobacco smoke (ETS). Material and Methods: In order to assess fetal exposure to toxic tobacco smoke compounds, samples of meconium from the offspring of women with different levels of tobacco smoke exposure, and the samples of saliva from the mothers were analyzed. Thiocyanate ion as a biomarker of tobacco smoke exposure, and other ions that are indices of such exposure were determined by means of ion chromatography. Results: The results of ion chromatography analysis of the meconium and maternal saliva samples for the presence of cations and anions (including thiocyanate ion) indicate that the concentration level of specific ions depends on the intensity of environmental tobacco smoke exposure of pregnant women. Conclusions: Based on the results, it can be concluded that meconium samples can be used to determine the substances from tobacco smoke. The results confirm the effect of smoking during pregnancy on the presence and content of substances from tobacco smoke.

  • Media społecznościowe: innowacja w kreowaniu polskich marek
    • Wioleta Kucharska
    2015

    Wartość marki jest kluczowym wskaźnikiem skuteczności przyjętych strategii marketingowych. Komunikacja marketingowa za pomocą mediów społecznościowych stanowi innowację w stosunku do coraz mniej efektywnej komunikacji za pomocą mediów tradycyjnych. Artykuł poświęcony jest analizie, za pomocą korelacji i regresji liniowej, relacji pomiędzy wartością najbardziej znanych polskich marek, a ich pozycją w mediach społecznościowych na przykładzie Facebooka.

  • Mentor & Student Reserch Lab
    • Hanna Obracht-Prondzyńska
    2015 Przegląd Urbanistyczny

    Relacja z realizacji projektów badawczych przygotowanych w ramach Mentor&Student Research Lab - Urban Transformations 2014

  • Metabolism of antitumour agent 1-nitroacridine derivative, C-1748 in pancreatic cancer cell lines
    • Anna Mróz
    • Barbara Borowa-Mazgaj
    • Zofia Mazerska
    2015 Acta Biochimica Polonica

    Pancreatic cancer has the highest mortality rate of all major cancers because of limited treatment options. Surgical removal of the tumour is possible only in its early stage, nevertheless the asymptomatic development very often makes unable an accurate diagnose. In the case of metastatic pancreatic cancer only chemotherapy, mainly with gemcitabine, can be offered to patients. However, common resistance towards gemcitabine imposes the research for new active compounds. The compound 9-(2′-hydroxyethylamino)-4-methyl-1-nitroacridine, C-1748 is the most potent antitumour derivative among 1-nitroacridines developed in our department. It possesses strong cytotoxic activity against colon and prostate cancer cells what allowed its selection for preclinical studies. Preliminary results indicate therapeutic potential of C-1748 against pancreatic cancers. The cytotoxic effect of an antitumour agent often depends on its metabolism leading to the activation or detoxification of the parent compound. The metabolism of C-1748 with human liver microsomes, human P450 reductase and in HepG2 cells was well studied and structures of four metabolites were identified. The aim of the current study is to investigate the metabolism of C-1748 in pancreatic cancer cell lines: Panc-1, MiaPaCa-2 and BxPC-3, which show different expression of cytochrome P450 isoenzymes. Both: medium and cellular extracts were analysed by HPLC/UV-Vis after drug treatment of the cells. A few metabolites were accumulated inside the cells whereas two products were found in the medium; but the metabolic profiles depended on the type of pancreatic cell line. One of the metabolite observed in all cancer cells was identified as the acridine derivative with an additional 6-membered ring. In conclusion, P450 mediated metabolism of C-1748 in pancreatic cancer cell lines strongly influenced its cytotoxicity. Moreover, C-1748 as a substrate for P450 isoenzymes in pancreatic cancer cells and a modulator of UGT activity, could be responsible for drug-drug interactions in the combined therapy.

  • Metals in the environment as risk factors for infectious diseases: gaps and opportunities
    • M. Ackland
    • Julia Bornhorst
    • George V. Dedoussis
    • Rodney R. Dieter
    • Jerome Nriagu
    • Józef Pacyna
    • John M. Pettifor
    2015

    This chapter aims to provide insights into current knowledge and gaps in our understanding of the influence that trace metals in the environment have on the pathogenesis of infectious diseases. By reducing immune function, trace metal deficiencies may substantially contribute to the global burden of diarhea, pneumonia, and malaria. Improved methods and biomarkers for assessing the risk of trace metals deficiencies and toxicities are required.