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Gdańsk University of Technology

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Publications from the year 2014

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  • Effects of Addictive Substances During Pregnancy and Infancy and Their Analysis in Biological Materials
    • Justyna Płotka-Wasylka
    • Sylwia Narkowicz
    • Żaneta Polkowska
    • Marek Biziuk
    • Jacek Namieśnik
    2014 REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY

    The use of addictive substances during pregnancy is a serious social problem, not only because of effects on the health of the woman and child, but also because drug or alcohol dependency it detracts from childcare and enhances the prospect of child neglect and family breakdown. Developing additive substance abuse treatment programs for pregnant women is socially important and can help ensure the health of babies, prevent subsequent developmental and behavioral problems (i.e., from intake of alcohol and other additive substances such as methamphetamine, cocaine, or heroine) and can reduce the cost to society. Because women of childbearing age often abuse controlled substances during their pregnancy, it is important to undertake biomonitoring of these substances in biological samples taken from the pregnant or nursing mother (blood, urine, hair, breast milk, swet, oral fluids), from the fetus and newborn (meconium, cord blood, neonatal hair and urine) and from both the mother and fetus (amniotic fluids, placenta). Maternal and neonatal biological materials reflect exposure in a specific time period and each of them has different advantages and disadvantages in terms of accuracy, time window of exposure and cost/benefit ratio. Sampling the placenta may be the most important biomonitoring step for assessing in utero exposure to addictive substances. The use of placenta in scientific research causes a minimum of ethical problems partly because the experiments are non-invasive, causing no harm to mother or child, and partly because placentas are discarded and incinerated after birth. Such samples, when properly analyzed may provide the key information necessary about fetal exposure to toxic substances, and may provide the groundwork for protecting the fetus or newborn and the mother from further damage. Sensitive and specific bioanalytical methods are commonly utilized to accurately measure for biomarkers of in utero drug exposure. Different immunoassays methods are used as screening methods for drug testing in the above reported specimens, however, the results from immunoassays should be carefully interpreted and confirmed by a more specific and sensitive chromatographic methods such as GC-MS or LC-MS. Although, the techniques for analysis are still being developed or refined, current methods are efficient and sensitive and provide valuable information of exposures to addictive substances and their metabolites.

  • Effects of consecutive apneas on pial artery pulsation and subarachnoid width in healthy subjects
    • Magdalena Wszędybył-Winklewska
    • Jacek Wolf
    • Ewa Świerblewska
    • Katarzyna Kunicka
    • Marcin Gruszecki
    • Wojciech Gumiński
    • Paweł J. Winklewski
    • Andrzej F. Frydrychowski
    • Leszek Bieniaszewski
    • Krzysztof Narkiewicz
    2014 JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY

    Hypercapnia is known to dilate the pial artery, disrupt cerebral autoregulation and increase pial artery pulsation. The cerebral blood flow velocity (CBFV) response to hypercapnia is biphasic. Below the threshold for the increase of blood pressure (BP) with carbon dioxide partial pressure (pCO2), the CBFV measurement reflects vascular reactivity to pCO2 alone at a constant BP. Above this threshold, the CBFV measurement provides an estimate of the cerebrovascular passive response to BP [4]. As a consequence, the CBFV response to apnea is driven by the interplay between BP and pCO2. In comparison with baseline values, BP drops at the onset of apnea, which is followed by an increase in BP and CBFV in the later part of the apneic episode. In the last decade, a new method based on infrared radiation (IR) called near-infrared transillumination/backscattering sounding (NIR-T/BSS) has been developed. NIR-T/BSS enables the assessment of changes in pial artery pulsation (cc-TQ), which reflect changes in pial artery compliance. In addition, NIR-T/BSS allows for measurement of the subarachnoid space (SAS) width (sas-TQ), which reflects changes in cerebrospinal fluid (CSF) volume and/or intracranial pressure (ICP). Contrary to near-infrared spectroscopy (NIRS), which relies on the absorption of IR by hemoglobin, NIR-T/BSS uses the SAS filled with translucent CSF as a propagation duct for IR. The main advantage of NIR-T/BSS technology is that cc-TQ reflects the functional status of the pial artery, and thus allows for direct assessment of the generalized effect of various factors affecting the pial artery (i.e. increased flow and/or pCO2, elevated ICP, etc.).

  • Effects of deviations from thermo-rheologically simple behavior of asphalt mixes in creep on developing of master curves of their stiffness modulus
    • Mariusz Jaczewski
    • Józef Judycki
    2014

    The paper presents the deviations from the thermo-rheologically simple behavior of asphalt mixes and their effects on the developing of master curves of stiffness modulus. Eleven different mixes were tested in three point bending test under constant load at temperatures –20°C, –10 °C and 0 °C, and in some cases at +10 °C. The test method was developed at the Gdansk University of Technology, Poland. The applied stress level was approximately equal to 30% of the flexural strength. It was found that the stiffness moduli of tested asphalt mixes at a certain low temperature and at a long time of loading greater than 600 s or 1200 s tended to the constant values unrelated to the time of loading. It resulted from the diminishing of viscoelastic flow of the material at long loading time at low temperature. Therefore, the stiffness modulus at long loading time was dependent upon temperature but was almost not related to the loading time. In most cases at temperatures –20 °C and at –10 °C a clear deviation from the time-temperature superposition principle was observed. These deviations were dependent on the type of bitumen used, type of asphalt mixture and the value of applied stresses. The deviations from thermoreologically simple behavior affected the formation of the master curve of stiffness modulus and might cause increase of thermal stresses in asphalt layers of pavements and disappearance of stress relaxation.

  • Effects of Different Aeration Modes on Ammonia Removal from Sludge Digester Liquors in the Nitritation-Anammox Process
    • Dominika Sobotka
    • Jacek Mąkinia
    • Krzysztof Czerwionka
    2014

    Sludge digester liquors can be responsible for up to one third of the nitrogen load to the biological step of wastewater treatment plants (WWTPs). The conventional process for ammonia removal via two sequential processes, i.e. nitrification and denitrification, is increasingly being challenged by a one-step process in which ammonium is oxidized directly to nitrogen gas e.g. ammonium oxidation (anammox) process. In this novel process, compared to a conventional nitrification and denitrification, the aeration and carbon-source demand is reduced by over 50 and 100%, respectively. This study focuses on the feasibility of nitrogen removal from sludge digester liquors from WWTPs in the combined nitritation/anammox process. The specific aim of this study was to determine the impact of continuous and intermittent aeration, as well as concentration of dissolved oxygen on the rate of ammonia removal in the combined nitritation/anammox process. Nitritation and anaerobic ammonium oxidation was carried out simultaneously in a sequencing batch reactor (SBR, V=10 dm3) with the nitrogen removal rate of 0,852 kg N m−3reactor d−1 and nitrogen removal efficiency of approximately 75%.

  • Efficiency comparison of selected endoscopic video analysis algorithms
    • Jan Cychnerski
    2014 Full text International Journal of Innovative Research in Computer and Communication Engineering

    In the paper, selected image analysis algorithms were examined and compared in the task of identifying informative frames, blurry frames, colorectal cancer and healthy tissue on endoscopic videos. In order to standardize the tests, the algorithms were modified by removing from them parts responsible for the classification, and replacing them with Support Vector Machines and Artificial Neural Networks. The tests were performed in an unified manner on a common, large movie database of real endoscopy videos. The test results often do not seem to confirm the high efficiency declared by their authors. A maximum of 80% sensitivity and specificity was achieved, while the authors often declared as much as 90%.

  • Efficiency Evaluation of High Performance Computing Systems Using Data Envelopment Analysis
    • Paweł Kaczmarek
    2014

    The paper presents an evaluation method of high performance computing (HPC) systems using multicriteria efficiency analysis. The Data Envelopment Analysis approach was applied and adapted to the specifics of HPC, which enabled us to compare relative efficiency of systems considering simultaneously multiple parameters. The analysis is based on the TOP500 list of world largest supercomputers and their parameters such as: the number of cores, theoretical performance, experimental performance and power consumption. Two complementary evaluations were performed with the following goals: find currently most efficient machines and compare time-dependent efficiency changes. Using the proposed method, experimental analysis was performed for a subset of one hundred machines and five year time window. Results show improvement in efficiency during recent years and significant importance of co-processor and graphical accelerators.

  • Efficiency of gas mixtures detection by resistive gas sensors
    • Janusz Smulko
    • Mateusz Kotarski
    2014

    Resistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Theeir main disadvantage is very limited selectivity. Practical use of gas sensors in environenmental applications requires determination of concentration of a few mixed gases at the same time. We would like to present recent results of gas detection improvement by utilizing a single gas sensor and additional measurements to get more information about the sensor ambient atmosphere. The measurements utilize fluctuactions enhanced sensing and temperature modulation to gather more data and therefore assure better selectivity. Various algorithms will be considered to detect gas mixtures. The considered methods can be applied in cheap portable systems or in more advanced devices due to more complex computations. Finally, the new method of gas sensors parameters modulations by UV irradiation will be mentioned as well.

  • EFFICIENCY OF GAS MIXTURES DETECTION BY RESISTIVE GAS SENSORS
    • Janusz Smulko
    • Mateusz Kotarski
    2014

    Resistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Their main disadvantage is very limited selectivity. Practical use of gas sensors in environmental applications (e.g., in sewage systems to protect workers, in air conditioning systems to monitor atmosphere quality) requires determination of concentration of a few mixed gases at the same time. We would like to present recent results of gas detection improvement by utilizing a single gas sensor and additional measurements to get more information about the sensor ambient atmosphere. The measurements utilize fluctuations enhanced sensing and temperature modulation to gather more data and therefore assure better selectivity. Various algorithms will be considered to detect gas mixtures. The considered methods can be applied in cheap portable systems or in more advanced devices due to more complex computations. Finally, the new method of gas sensors parameters modulations by UV irradiation will be mentioned as well.

  • Efficiency of the Use of LTE System Radio Resources in Highway Transport Enironment
    • Sławomir Gajewski
    2014 Archives of Transport System Telematics

    The paper describes the problem of analysis of throughput-coverage characteristics of the LTE system. Simulation results of the efficiency of the use of LTE radio resources are presented. Simulation studies on the basis of original model of the LTE network simulator were carried out. In addition, the evaluation of throughput for a single connection, and available capacity were evaluated in the context of the use of the same available frequency band in all cells of a cellular network. The results were also analysed in view of LTE transport applications. The results shows that from the point of view of transport applications of LTE better results on system performance gives the PFR method.

  • Efficiency of thermomechanical reclaiming of ground tire rubber conducted in counter-rotating and co-rotating twin screw extruder
    • Krzysztof Formela
    • Magdalena Formela
    2014 Full text Polimery

    In this article the results of research on a continuous thermomechanical reclaiming process of ground tire rubber (GTR) conducted in a twin screw extruder are presented. The effects of the rotation direction (co-rotating/counter-rotating), design of co-rotating plasticizing units and the rotational speed of the screws on the extruder working parameters, sol fraction and the degree of reclaiming in the obtained products were described. The influence of secondary vulcanization on cure characteristics as well as mechanical properties of revulcanizates, and blends of reclaimed rubber and styrene-butadiene rubber (SBR) were determined. Based on the obtained results, it was concluded that the application of counter- rotating plasticizing system (i.e. screw profile A), consisting mainly of transport elements with different pitch, increases the time during which ground tire rubber is exposed to the barrel temperature. The use of co-rotating plasticizing system, equipped with kneading elements and characterized by constant pitch, causes that the retention time of ground tire rubber in the extruder barrel is much shorter. In the case of co-rotating plasticizing system, it is also higher shear forces (then in counter-rotating screw configuration), besides temperature, acts on ground tire rubber, and converts mechanical energy into heat. Testing of styrene-butadiene rubber-ground tire rubber/reclaimed ground tire rubber (SBR-GTR/dGTR) compounds confirmed that the reclaiming process has positive influence on properties of obtained products.

  • Efficient Method for the Synthesis of Functionalized Basic Maleimides
    • Natalia Salewska
    • Maria Jolanta Milewska
    2014 Full text JOURNAL OF HETEROCYCLIC CHEMISTRY

    A three-step procedure involving Diels-Alder condensation of maleic anhydride with furane, formation of N-substituted imide upon reaction with appropriate diamine and a final retro Diels-Alder regeneration of the maleic carbon-carbon double bond is proposed for an unequivocal synthesis of N-substituted basic maleimides. The novel method is characterized by mild reaction conditions, easy work-up, high yields and no need for additional catalysis.

  • Efficient Multi-Objective Simulation-Driven Antenna Design Using Co-Kriging
    • Sławomir Kozieł
    • Adrian Bekasiewicz
    • Ivo Couckuyt
    • Tom Dhaene
    2014 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION

    A methodology for fast multi-objective antenna optimization is presented. Our approach is based on response surface approximation (RSA) modeling and variable-fidelity electromagnetic (EM) simulations. In the design process, a computationally cheap RSA surrogate model constructed from sampled coarse-discretization EM antenna simulations is optimized using a multi-objective evolutionary algorithm. The initially determined Pareto optimal set representing the best possible trade-offs between conflicting design objectives is then iteratively refined. In each iteration, a limited number of high-fidelity EM model responses are incorporated into the RSA model using co-kriging. The enhanced RSA model is subsequently re-optimized to yield the refined Pareto set. Combination of low- and high-fidelity simulations as well as co-kriging results in the low overall optimization cost. The proposed approach is validated using two UWB antenna examples.

  • Efficient production of Staphylococcus simulans lysostaphin in a benchtop bioreactor by recombinant Escherichia coli.
    • Piotr Szweda
    • Grzegorz Gorczyca
    • Paweł Filipkowski
    • Magdalena Zalewska
    • Sławomir Milewski
    2014 PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY

    Lysostaphin is an enzyme with bactericidal activity against Staphylococcus aureus and other staphylococcal species. In spite of many advantages and promising results of preliminary research, the enzyme is still not widely used in medicine, veterinary or as a food preservative. One of the most important factors limiting application of the enzyme in clinical or technological practice is the high costs of its production. In the present study we have determined the optimal conditions for lysostaphin production in 5 l batch bioreactor. The enzyme production was based on, constructed earlier in our laboratory, heterologous, E. coli expression system assigned as pBAD2Lys. An evident influence of both physicochemical conditions of the process (areation, pH and temperature) and composition of the growing media on the amount and activity of produced enzyme was noticed. The efficiency of production of about 13000 U/L have been achieved in the optimal conditions of the production process: low aeration (400 rpm of mechanical stirrer), pH = 6 and temperature of 37 °C in classical LB medium. Further, about twofold improvement in the production efficiency of the enzyme was achieved as a result of modification of composition of growing media. Finally over 80 000 units of lysostaphin were obtained from one (batch) bioreactor −3 L of culture of E. coli TOP10 F' transformed with pBAD2Lys plasmid. From our best knowledge, it is the most efficient method of production of recombinant lysostaphin in E. coli expression systems described to date.

  • Ekologiczna sanitacja. Część I – rozdział i zagospodarowanie ścieków szarych
    • Agnieszka Tuszyńska
    • Dorota Woch
    2014 Wodociągi - Kanalizacja

    W ostatnich latach, szczególnie w Europie Zachodniej (Niemcy, Austria, Szwajcaria) i krajach skandynawskich (Szwecja, Norwegia), zaobserwować można coraz większe zainteresowanie sanitacją ekologiczną (w jęz. ang. Ecological Sanitation). Zrównoważoną sanitację można zdefiniować jako sanitację, która chroni i promuje zdrowie ludzkie, nie przyczyniając się do degradacji środowiska, jest technicznie dopasowana oraz ekonomicznie akceptowalna. Istnieje wiele różnych wariantów technicznych zrównoważonej sanitacji, a wybór odpowiedniego rozwiązania zależy od warunków lokalnych. Aby zaprezentować różnorodność metod w niniejszym artykule przedstawiono przykłady sanitacji. Przykłady te prezentują rozwiązania techniczne od podstawowych metod, po zaawansowane technologie. W części I przedstawiono sposoby odprowadzania i zagospodarowania ścieków szarych zgodnie z panującymi zasadami sanitacji ekologicznej.

  • Ekologiczna sanitacja. Część II – rozdział i zagospodarowanie ścieków żółtych
    • Agnieszka Tuszyńska
    • Dorota Woch
    2014 Wodociągi - Kanalizacja

    W ostatnich latach zaobserwować można coraz większe zainteresowanie sanitacją ekologiczną. Dzięki ekologicznej sanitacji odpady bytowe są usuwane i ponownie poddane zagospodarowaniu, przy całkowitym zapewnieniu odpowiednich warunków higienicznych oraz odzysku substancji odżywczych. Ten niedrogi i łatwy w użytkowaniu sposób stanowi alternatywę tradycyjnej kanalizacji „end-of-pipe”. Jednym z rozwiązań sanitacji ekologicznej jest instalacja sanitarna z rozdziałem ścieków żółtych przy zastosowaniu bio-toalety. Odseparowana uryna pomimo, że stanowi jedynie ok. 2 % ścieków bytowych, reprezentuje aż 80 % azotu, niemal 50 % fosforu i 54 % potasu. To innowacyjne rozwiązanie pozwala, by związki odżywcze ponownie mogły trafić do obiegu naturalnego. W niniejszym artykule przedstawiono przykłady instalacji eko-sanitarnej z rozdziałem ścieków żółtych oraz wskazówki praktyczne dotyczące jej projektowania i budowy, poparte doświadczeniami uzyskanymi z analizy pracy obiektów istniejących. Niniejszy artykuł może służyć rozpowszechnieniu wśród projektantów, instalatorów i inwestorów informacji o alternatywnych sposobach zagospodarowania ścieków bytowych.

  • Ekonomiczne aspekty strategii utrzymania torów kolejowych
    • Zbigniew Kędra
    2014 Full text Logistyka

    W ostatnich lata coraz więcej uwagi poświęca się analizie kosztów cyklu życia (Life Cycle Cost - LCC) w zakresie planowania strategii utrzymania infrastruktury kolejowej. Większość prac ogranicza się jednak do kosztów bezpośrednich (planowanych), takich jak budowy, konserwacji, odnowienia i utylizacji. Takie podejście prowadzi do niedoszacowania kosztów wynikających z niskiej jakości geometrii toru. W artykule przedstawiona została metoda planowania strategicznego kosztów cyklu życia infrastruktury kolejowej, która stosowana jest w wielu krajach europejskich. W obliczeniach uwzględnione zostały koszty ponoszone przez przewoźników kolejowych i pasażerów oraz koszty utrzymania i odbudowy infrastruktury kolejowej. Przedstawiono również przykładowe modele degradacji geometrii toru kolejowego i wpływ niskiej jakości toru na koszt cyklu życia.

  • Ekonomiczne aspekty zastosowania techniki Mobilnych Pomiarów Satelitarnych przy regulacji osi toru
    • Cezary Specht
    • Władysław Koc
    • Piotr Chrostowski
    • Jacek Szmagliński
    2014 Logistyka

    Od 2009 roku interdyscyplinarny zespół naukowy Politechniki Gdańskiej i Akademii Marynarki Wojennej (a obecnie Akademii Morskiej w Gdyni) rozwija technikę Mobilnych Pomiarów Satelitarnych toru kolejowego. Technika ta polega na objeździe trasy ciągnikiem szynowym z przyczepą (wagonem-platformą) lub wózkami, z zainstalowanymi na tych pojazdach odbiornikami sygnałów satelitarnych. Umożliwia ona precyzyjne określenie współrzędnych osi toru w bezwzględnym układzie odniesienia. Już pierwsze przeprowadzone z jej wykorzystaniem pomiary wykazały, że ukształtowanie geometryczne torów na sieci PKP pozostawia dużo do życzenia − stwierdzone deformacje poziome są znacznie większe niż można się było spodziewać. Jako podstawową przyczynę takiego stanu rzeczy wskazano stosowane sposoby regulacji geometrycznej osi toru. W pracy omówiono uwarunkowania procesu kształtowania układów geometrycznych toru kolejowego i scharakteryzowano metodykę regulacji osi toru opartą na pomiarze stacjonarnym (obecnie wykorzystywaną na kolei). Wskazano na korzyści wynikające z zastosowania techniki Mobilnych Pomiarów Satelitarnych, która z uwagi na zdecydowanie mniejszą czasochłonność pozwala na zwiększenie dokładności dzięki korzystaniu z większej liczby współrzędnych. Szczególnie istotne okazują się przy tym aspekty ekonomiczne. Ponieważ regulacja osi toru jest procesem ciągle się powtarzającym, dalsze utrzymywanie dotychczasowej sytuacji prowadzić będzie do niekorzystnych skutków finansowych.

  • Ekspertyza dotycząca odpowiedzi na pytanie "czy smartfon i tablet są urządzeniami podobnymi do magnetofonów i magnetowidów oraz czy urządzenia te mogą być zakwalifikowane do grupy urządzeń kopiujących"
    • Sławomir Gajewski
    • Małgorzata Gajewska
    • Marcin Sokół
    2014

    W ekspertyzie odpowiedziano na pytanie "czy smartfon i tablet są urządzeniami podobnymi do magnetofonów i magnetowidów oraz czy urządzenia te mogą być zakwalifikowane do grupy urządzeń kopiujących"

  • Ekspertyza głowicy napowietrznej EHFVC 145 po skutkach zwarć w układzie elektroenergetycznym linii 110 kV zasilających stację R110 kV Rafineria
    • Marek Olesz
    2014

    W ekspertyzie oceniono poprawność wykonania i podłączenia głowic 110 kV oraz analizowano przebieg zdarzeń w sieci elektroenergetycznej. Ustalono przyczynę uszkodzenia oraz przebieg zjawisk starzeniowych w układzie izolacyjnym.

  • Ekspertyza oddziaływania napowietrznych linii wysokiego napięcia
    • Kazimierz Darowicki
    • Michał Narożny
    2014

    Wykonano obliczeń oddziaływania linii 400kV i 110kV na gazociągi DN500, DN400 i DN100 w miejscach ich kolizji oraz wyznaczono gęstości upływających prądów przez jednostkowy defekt o powierzchni 1cm^2.