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Gdańsk University of Technology

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Publications from the year 2013

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  • Four-body recombination in organic bulk heterojunction solar cells: an alternative interpretation
    • Jędrzej Szmytkowski
    2013 SEMICONDUCTOR SCIENCE AND TECHNOLOGY

    We demonstrate a new interpretation of the previously reported quadrimolecular recombination in organic bulk heterojunction solar cells. It is suggested that the recently described (Szmytkowski 2012 Phys. Status Solidi RRL 6 300) interaction between exciton and electron–hole Langevin bound pair formed across the donor–acceptor interface is a four-particle process. This is in opposition to the treatment of this effect as a three-particle phenomenon which might be intuitively expected because one exciton annihilates physically on one charge carrier. An excellent agreement between experimental data and theoretical calculations has been obtained. The novelty of the presented interpretation is of fundamental importance to understand mechanisms which limit the efficiency of organic solar cells.

  • Four-state stochastic model of changes in the reliability states of a motor vehicle
    • Jerzy Girtler
    • Marek Ślęzak
    2013 Full text Eksploatacja i Niezawodność - Maintenance and Reliability

    The properties of semi-Markov processes have been generally characterized and the applicability of the theory of such processes to the determining of the reliability of motor cars and other road vehicles has been explained. A formal description of the process of changes in the motor vehicle technical states considered as reliability states and a model of this process in the form of a one-dimensional stochastic process have been presented. The values of this process are the technical states of the motor vehicle in question that have significant practical importance. A four-state set of states interpreted as follows has been adopted: full (complete) serviceability, partial (incomplete) serviceability,task-limiting serviceability,and complete (total) unserviceability. Based on the initial distribution adopted and the functional matrix worked out, the boundary distribution of the process of changes in the technical (reliability) states of the motor vehicle has been defined. The probability of the vehicle being fully serviceable has been considered a measure of the vehicle reliability for a long period of vehicle operation. A possibility of defining the vehicle reliability in the form of a probability that a task would also be fulfilled by the vehicle being partially serviceable has also been indicated.

  • Fractional equations of Volterra type involving a Riemann Liouville derivative
    • Tadeusz Jankowski
    2013 Full text APPLIED MATHEMATICS LETTERS

    In this paper, we discuss the existence of solutions of fractional equations of Volterra type with the Riemann Liouville derivative. Existence results are obtained by using a Banach fixed point theorem with weighted norms and by a monotone iterative method too. An example illustrates the results.

  • Free convection of water-Al2O3 nanofluid from horizontal porous coated tube
    • Janusz Cieśliński
    • Katarzyna Ronewicz
    2013 Key Engineering Materials

    Nanofluids are expected to enhance heat transfer in many thermal systems. Present efforts are concentrated on boiling heat transfer of nanofluids, although single phase convection is of key importance in various appliances such as car radiators or heating systems. This paper presents experimental results of heat transfer during free convection of water-Al3O3 nanofluid from horizontal tube covered with metallic porous coating. Contrary to theoretical considerations deterioration of heat transfer was observed.

  • Free convection of water-Al2O3 nanofluid from horizontal porous coated tube
    • Janusz Cieśliński
    • Katarzyna Ronewicz
    • Mateusz Pietrulewicz
    • Tomasz Kaczmarczyk
    2013

    The main aim of the present study was to investigate the influence of nanoparticles on heat transfer coefficients during free convection of water-Al2O3 nanofluid from horizontal porous coated tube under atmospheric pressure for nanoparticle concentration of 0.01% by weight. Contrary to published data present study concerns on free convection of nanofluids in extensive, quiescent fluid.

  • Freeze-casting jako metoda wytwarzania porowatych ceramik
    • Paweł Gdaniec
    2013

    Praca przedstawia opis metody Freeze-casting stosowanej do wytarzania porowatych materiałów ceramicznych. Zaprezentowano ogólny opis techniki, metodologie oraz sposoby kontrolowania struktury otrzymanej ceramiki.

  • Frequency response spectra applied to assess efficiency of the training techniques
    • Tomasz Kucharski
    2013 Key Engineering Materials

    The purpose of the research is to assess the increase of the muscle strength and power. Movement of the human body when the moving one impacts a stationary or moving body is taken under consideration. The waveform produced by an impact is transformed into frequency domain. The acceleration record is transformed as a complex spectrum, by the use of a Discrete Fourier Transformation. In this paper the applications of the discrete Fourier transform is discussed and it was pointed out that it can be fruitfully applied to analyze movement techniques during competition or training exercises. The acceleration response spectrum contains knowledge about efficiency of certain techniques. It has distinct features which can show that the energy is concentrated around several discrete frequencies. Data from the shape of a frequency response spectra curve can provide the coach and the performer with valuable information on technique and also give information on recommendations with respect to corrections and adjustments that can lead to performance enhancement. In this paper, the technique of a database creation is proposed what allows us to establish a particular set of circumstances under a specified protocol to observe and evaluate the implications of the resulting observations.

  • Fully Isohexide-Based Polyesters: Synthesis, Characterization, and Structure-Properties Relations
    • Jing Wu
    • Pieter Eduard
    • Lidia Jasińska-Walc
    • Artur Różański
    • Bart A. J. Noordover
    • Daan S. Van Es
    • Cor E. Koning
    2013 MACROMOLECULES

    Here we present a novel series of biobasedpolyesters solely based on renewable isohexide building blocks,synthesized via melt polymerization. The recently developedisoidide dicarboxylic acid (IIDCA) was polymerized with rigidrenewable diols such as isosorbide (IS), isomannide (IM),isoidide (II), and the novel 2,5-methylene-extended isoididedimethanol (IIDML). Both IIDCA and IIDML weredeveloped to increase the reactivity of the isohexide buildingblock, while retaining rigidity and hence the beneficial effectson Tg. Compared to the parent isohexides, IIDML showed amarkedly higher reactivity, resulting in three to four timeshigher weight-average molecular weight (Mw) values of thesynthesized polyesters. The molecular structure of the novel polyesters was analyzed by 1H, 13C and 2D-COSY NMR techniques,confirming that the stereoconfigurations of the isohexide moieties were preserved under the applied polymerization conditions.The II/IS-based polyesters have high Tg values noted of 70 and 85 °C, respectively, while the IIDML-based polyester has a lowerTg of approximately 45 °C, yet with an higher degree of crystallinity than the parent isohexide-based polyesters. A systematicstudy on structure-thermal properties relations comparing these novel polyesters with, e.g., aliphatic polyesters reveals that, whenincorporated into polyesters, both IIDCA and IIDML are able to increase the Tg by approximately 70 °C, which is comparable tothe parent isohexides. Given the enhanced reactivity, high thermal stability and the retained ability to increase the Tg, IIDML is apromising renewable building block for performance polymers.

  • Fully Separated Flow Control Using DBD Plasma Actuators Located at the Leading Edge of an Airfoil
    • Annie Leroy
    • Pierre Audier
    • Dunpin Hong
    • J. Podliński
    • Artur Berendt
    • Jerzy Mizeraczyk
    2013 ERCOFTAC Bulletin

    In the framework of the PLASMAERO European project, experiments were conducted to investigate the authority of surface DBD plasma actuators to alter a fully separated flow around an airfoil in order to improve its aerodynamic performances in its natural stall regime. In this paper, unsteady excitation control is more specifically investigated. The key control parameter studied here is the burst frequency which periodically imposes switching on and off the actuator. Results show that it is possible to perform a modification of the massively separated flow by unsteady excitation near the leading-edge. However, depending on the forcing frequency and the post-stall regime, two different flow modification mechanisms can be observed leading to either the reduction of the flow separation or the occurrence of a mean large lifting vortex next to the suction side. In both cases, a large lift increase is obtained.

  • Functional safety and reliability analysis methodoloogy for hazardous industrial plants
    • Kazimierz Kosmowski
    2013

    This monograph is devoted to current problems and methods of the functional safety and reliability analyses of the programmable control and protection systems for industrial hazardous plants. The results of these analyses are useful in the process of safety management in life cycle, for effective reducing relevant risks at the design stage, and then controlling these risks during the operation of given installation. The methodology outlined is oriented on safety functions and factors that influence significantly specific risks. It is applicable to the hazardous plants of the process industry sector and the nuclear power plants as well. The main objective of the monograph was to present the state of the art of the functional safety concept and its relations to technical and organisational solutions that can be applied in hazardous plants in the light of current scientific domain literature, relevant international standards and other documents related to the safety and security, issued by international organisations. The purpose was also to propose a coherent methodology for dealing with selected functional safety aspects of the control and protection systems of nuclear power plants, designed as the safety layers according to “defence in depth” conception. The human factors in designing of the human machine interface are also considered. The scope of the monograph includes in consecutive chapters following issues: the functional safety concept and challenges, determining and verifying the safety integrity level under uncertainty, the layer of protection analysis including human factors and the cost-benefit analysis of functional safety improvement in the context of safety criteria. A classification of structures, systems and components is presented, useful in designing the control and protection systems of nuclear power plants. Using of a framework for the risk-informed decision making is proposed.

  • Functionalized azobenzocrown ethers as sensor materials—The synthesis and ion binding properties
    • Ewa Wagner-Wysiecka
    • Tomasz Rzymowski
    • Mirosław Szarmach
    • Marina S. Fonari
    • Elżbieta Luboch
    2013 SENSORS AND ACTUATORS B-CHEMICAL

    New 13- and 16-membered azobenzocrown ethers with aromatic amino, amide, ether–ester or ether–amide residue in para position to an azo moiety were obtained. Acid–base properties and ion binding ability of the colored compounds were studied by spectroscopic methods: UV–vis, fluorimetry and 1H NMR spectroscopy. Selected azobenzocrowns were tested as ionophores in ion-selective membrane electrodes (ISEs) – classic and miniature all solid state. The X-ray structure of the sodium complex of ether–ester derivative of 16-membered azobenzocrown was presented.

  • Fundamenty palowe. Badania i zastosowanie. - Tom 2
    • Kazimierz Gwizdała
    2013

    Stosowanie nowoczesnych rozwiązań zgodnie z EC7 wymaga wzmożonej kontroli w całym procesie produkcji, wykonania i eksploatacji Stosowanie nowoczesnych rozwiązań zgodnie z Eurokodem 7 wymaga wzmożonej kontroli w całym procesie produkcji, wykonania, odbioru i eksploatacji fundamentów palowych. Istotne znaczenie mają warunki geologiczne, hydrogeologiczne i geotechniczne jako podłoże do posadowienia budowli. W tomie drugim przedstawiono: · badania statyczne i dynamiczne nośności pali, · pale i ustroje palowe obciążone siłami poziomymi, · zastosowania fundamentów płytowo-palowych, · oddziaływanie środowiskowe na fundamenty palowe i fundamenty głębokie. Książka bogato ilustrowana przykładami rozwiązań konstrukcyjnych i zdjęciami z placów budowy popartymi spostrzeżeniami praktycznymi Autora. Podręcznik przeznaczony dla studentów kierunków budownictwo, architektura i inżynieria środowiska. Będzie też przydatny dla inżynierów pracujących w biurach projektów i w wykonawstwie robót palowych, a także dla pracowników nadzoru budowlanego.

  • Fungal Typin Methods
    • Anna Brillowska-Dąbrowska
    2013 MYCOSES

    The broad application of the molecular techniques in mycoses diagnosis is related to increase of infections caused by fungi in many countries. The oldest typing methods relaying on fenotypic observation, physiological and biochemical examination have had very limited importance from decades. Novadays, the molecular biology methods took their place. Most of the genotyping methods have been devoleped to be applied for typing of bacteria and viruses and are applied for fungi typing. However, the proper choice of the method is possible only when differences between bacterial and fungal genotypes are considered. Moreover, such differences can be found even within one genus, e.g. diploid Candida albicans and haploid Candida glabrata. The next issue that should be considered is that the proper choice of the method depends on the research aim to be obtained. This issue is closely related to the discrimination potential of the particular methods e.g. DNA-DNA hybridisation methods allow to distinguish genera or species, but are not useful for distinguishing strains. Moreover, some of the methods, e.g. sequencing can be applied to distinguishing the isolates on almost all the taxonomic levels - order, family, genus, species or strains. However, the definition of typing of microorganisms is their distinguishing within species or subspecies level. The choice of the typing method also depends on the knowledge of the genomes of fungi to be typed. Some methods, such PCR fingerprinting (RAPD, AP-PCR, DAF) or techniques based on the adapters ligation (LM PCR), don’t require the sequences of the genomes or their fragments, the others are based on their comparison (Multilocus Sequence Typing - MLST). To understand the possibilities and limitations of genotyping methods, their principles should be carefully studied. Various sequencing strategies and PCR based techniques, which can be applied in genotyping, will be presented The techniques based on restriction fragment length polymorphism (RFLP) with or without hybridization to probes (Southern), although their use is less extensive and is limited mostly to research laboratories, will be also reviewed. Beside the choice of the technique, the influence of experimental errors on the obtained results should be also considered. Moreover, it is important to remember that small differences not always are meaningfull and do not always allow for recognising the different strains.

  • Funkcje sektora bankowego w gospodarce: przypadek Indii
    • Adam Marszk
    2013 Ekonomia. Prace Naukowe Uniwersytetu Ekonomicznego we Wrocławiu

    Celem artykułu jest zbadanie wpływu sektora bankowego na sferę realną gospodarki w Indiach i określenie, w jakim stopniu oddziałuje pozytywnie, a w jakim stanowi barierę rozwojową. W pierwszej części tekstu omówione zostały teoretyczne propozycje dotyczące zależności między działalnością banków a sferą realną. Cztery podstawowe funkcje banków to zwiększanie efektywności alokacji zasobów, mobilizacja oszczędności, ograniczanie ryzyka oraz zmniejszanie kosztów transakcyjnych. Następna część artykułu poświęcona jest historii i obecnej sytuacji sektora w Indiach. Mimo przeprowadzanej od początku lat 90. XX w. liberalizacji branży, zakres kontroli państwowej jest nadal szeroki i przejawia się przede wszystkim w nakładaniu minimalnych limitów kredytów, które muszą być kierowane do tzw. sektorów priorytetowych. Stanowi to istotny problem dla banków, ponieważ portfel tego typu kredytów jest niskiej jakości i znaczący ich odsetek jest klasyfikowany jako kredyty zagrożone. Sektor bankowy jako całość jest słabo rozwinięty w stosunku do krajów bogatszych, zarówno pod względem rozmiarów, jak i dostępności i jakości oferowanych usług. O zacofaniu świadczy również niska wartość udzielanych kredytów w odniesieniu do depozytów, nie tylko znacznie niższa niż w krajach wysoko rozwiniętych, ale też niż w pozostałych krajach grupy BRIC, do której zaliczane są Indie. Banki indyjskie udzielały kredytów głównie przedsiębiorstwom z sektora przemysłowego (45% łącznej wartości) oraz z sektora usługowego (ok. 24%). Pozytywnie, biorąc pod uwagę istotne bariery rozwoju Indii, należy ocenić wysoki odsetek kredytów udzielonych przedsiębiorstwom infrastrukturalnym, zwłaszcza w branży produkcji i dystrybucji energii elektrycznej. Na podstawie wymienionych i innych danych dotyczących różnych aspektów funkcjonowania banków w Indiach, należy stwierdzić, że spełnia on swoje funkcje makroekonomiczne w ograniczonym zakresie. Funkcje mobilizacyjna i zmniejszania kosztów transakcji nie są realizowane w dostatecznym stopniu z powodu niskiego stopnia nasycenia usługami bankowymi. Funkcja alokacyjna, związana z poprawą efektywności alokacji kapitału, a także funkcja ograniczania ryzyka, również są wypełniane w niewielkim stopniu głównie z powodu rządowego programu wsparcia dla wybranych sektorów i związanego z nim wysokiego odsetka kredytów zagrożonych.

  • Funkcjonalność platformy KASKADA
    • Jerzy Proficz
    • Adam Brzeski
    • Paweł Czarnul
    • Bartłomiej Daca
    • Rafał Knopa
    • Mateusz Westa
    2013

    Przedstawiono opis funkcjonalności platformy KASKADA, a w szczególności jej architektury oprogramowania, mechanizmów zarządzania oraz biblioteki usług aplikacyjnych. Zaprezentowano poszczególne komponenty platformy, opisano ich budowę i implementację podstawowych funkcji, jak również zasygnalizowano problemy jakie wystąpiły podczas jej implementacji.

  • Funkcjonowanie skrzyżowań z wyspą centralną ze zmienną wielkością wewnętrznych powierzchni akumulacji.
    • Wojciech Kustra
    • Lucyna Gumińska
    2013

    W niniejszym artykule przedstawiono wybrane zagadnienia dotyczące funkcjonowania skrzyżowań z wyspą centralną przy dużych i bardzo dużych natężeniach ruchu. Ten typ skrzyżowań jest często stosowany w Polsce w centrach miast na ulicach wielopasowych i jest dość powszechny w przypadku występowania torowiska tramwajowego w pasie dzielącym jezdnie. Przy dużym udziale natężenia pojazdów skręcających w lewo lub zawracających, wyspa centralna staje się skrzyżowaniem niezmiernie trudnym do sterowania ruchem. Niewielki obszar akumulacji w obrębie wyspy środkowej, jest miejscem newralgicznym, istotnie wpływającym na przepustowość tego typu skrzyżowań. Dla potrzeb prowadzonych analiz, wykorzystano modele mikrosymulacyjne wykonane w programie PTV Vissim, które umożliwiły odwzorowanie warunków ruchu i rozwiązanie kilku ważnych zagadnień przy wyznaczaniu ich przepustowości.

  • FURTHER REMARKS ON THE NEO-CLASSICAL NAVIER-STOKES EQUATIONS
    • Paweł Ziółkowski
    • Janusz Badur
    2013

    The seminal Navier-Stokes equations have been stated yet before creation of principles of thermodynamics and the first and second laws. In the literature there is the common opinion that the Navier-Stokes equations cannot be taken as a thermodynamically correct model of “working fluid” which is able to describe transformation of “ heat” into “work” and vice versa. Therefore, in the paper, a new exposition of thermodynamically consistent Navier-Stokes equations is presented. Keeping the line of reasoning, based on the Gyftopoulos and Beretta concept of thermodynamics [1], we will introduce the basic concepts of thermodynamics with the notion of “heating” and “working” fluxes, and will extend the Gyftopoulos and Beretta approach into three-dimensional continuum thermodynamics. In our approach notion of “energy” and “energy interactions” play a dominant role. The main inconsistencies connected with the internal energy concept as a form of ,,energy storage’’ and the transformations of different forms of energy are evaluated. Thus, the balance of energy is finally presented as a sum of internal, kinetic, potential and radiation energies in the system that are compensated by the total energy flux, which consists of working, heating, chemical, electric, magnetic and radiation energy fluxes at the system boundaries. The law of energy conservation can be considered as the most important one which is superior over any other laws of nature. Summarizing of the consequences of the Gyftopoulos-Beretta thermodynamics exposition – the presented above mathematical model of continuum – the neo-classical Navier-Stokes - has a thermodynamic consistency, what means that unknown fields assigned from a proper set of governing equations must additionally fulfill the condition of not creating energy from nothing [Se= 0 , eq.(9)].

  • FURTHER REMARKS ON THE SURFACE VIS IMPRESSA CAUSED BY A FLUID-SOLID CONTACT
    • Janusz Badur
    • Paweł Ziółkowski
    2013

    It is well-known that, nano-mechanics should take into account not only physical phenomena occuring within the bulk but, first of all, the physical phenomena appropriate for a surface of two materials contact. The huge volume density of internal surfaces as well countours lines located within the nanomaterial results in our interest in, apart from classical form of mass, momentum and entropy transport, those modes of transportation where a carrier of physical property follows a free path having of a dimension greater than nanostructure characteristic dimension. The mode of transport dominated by mechanical, thermal and electrical slip of carried bounding off walls (a surface of separation) is called usually in physics ”a ballistic mode”. In the paper the appropriate Newtonian surface vis impressa responsible for the ballistic mode of transport is defined, classified and explained. We postulate that generally surface vis impressa can be additivelly splited onto friction and mobility forces.

  • Garść refleksji o parametryzacji w nauce i szkolnictwie wyższym w Polsce
    • Krzysztof Leja
    2013 Nauka Polska. Jej Potrzeby Organizacja i Rozwój

    W artykule zawarto uwagi o parametryzacji jednostek organizacyjnych uczelni przeprowadzonej w 2013 r., dostrzegając jej zasadność i koncentrując się głównie na słabościach.

  • Gas boiler as a heat source for the domestic micro-CHP
    • Dariusz Mikielewicz
    • Jan Wajs
    • Jarosław Mikielewicz
    2013

    In the presented analysis a commercially available domestic gas boiler as a heat source for domestic ORC is considered. The applicability of the gas boiler (De Dietrich with thermal power 25 kW) coupled with the laboratory prototype micro ORC setup has experimentally studied. The main aim of the study is to determine the working fluid temperature, attainable heat rates and efficiencies of the whole system. Preliminary investigations show that the boiler was able to provide the saturated/superheated vapour of ethanol and HFE-7100 as a working fluid at required conditions needed in the ORC system and it can be utilized as a heat source in the domestic micro-CHP. Obtained results encourage for further development of micro cogeneration units.