Repozytorium publikacji - Politechnika Gdańska

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• Krzysztof Wróblewski

2015

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10 lat konkursu: Najlepsza przestrzeń publiczna województwa pomorskiego

• Hanna Obracht-Prondzyńska

2015

album zawiera nie tylko przegląd zrealizowanych w ostatnich latach projektów, które charakteryzują się wysoką jakością zastosowanych rozwiązań służących mieszkańcom. Jest również prezentacją zbioru dobrych praktyk, dzięki którym miasta, miasteczka i wsie województwa pomorskiego stają się wizytówką regionu.

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2-outer-independent domination in graphs

• Nader Jafari Rad
• Marcin Krzywkowski

2015 Pełny tekst NATIONAL ACADEMY SCIENCE LETTERS-INDIA

We initiate the study of 2-outer-independent domination in graphs. A 2-outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of V(G)\D has at least two neighbors in D, and the set V(G)\D is independent. The 2-outer-independent domination number of a graph G is the minimum cardinality of a 2-outer-independent dominating set of G. We show that if a graph has minimum degree at least two, then its 2-outer-independent domination number equals the vertex cover number. Then we investigate the 2-outer-independent domination in graphs with minimum degree one.

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3D modelling of liquid fuels base infrastructure for the purpose of visualization and geometrical analysis

• Artur Janowski
• Jakub Szulwic
• Mateusz Żuk

2015

The paper presents the methodology for obtaining a 3D model of the tank for liquid fuels on the basis of the terrestrial laser scanning and its processing for the analysis of tanks geometry. The development process indicates the possibility to obtain the reliable results useful for the evaluation of the tank side surfaces geometry (shells). The result of the development is a 3D model of the tank, taking into account the individual characteristics of the object: the creation of a 3D model is focused on possible reproduction of the geometry without using the imposed shapes of geometrical figures and patterns of the industrial installation components.

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3D porous graphene-based structures- synthesis and applications

• Kamila Sadowska
• Izabela Kondratowicz
• Wojciech Sadowski

2015

Porous carbon-based materials are of the great industrial and academic interest due to their high surface area, low density, good electrical conductivity, chemical inertness and low cost of fabrication. Up to now, the main approach to obtain porous carbon structures has involved the pyrolysis of carbonaceous natural or synthetic precursors. After the isolation of graphene, the interest in 3D porous graphene-based structures (called graphene foams, sponges, networks or frameworks) aroused and methods of their production were introduced. Their high porosity alongside their chemical and biological inertness makes such 3D porous graphene-based structures good candidates as chemical adsorbents and tissue-engineering scaffolds. However, the main advantage, as compared to other carbon-based structures, is their high electrical conductivity, thus they are mainly examined as an electrode material in devices such as (bio)fuel cells, batteries, and supercapacitors.

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3D Sound Intensity Measurement Around Organ Pipes Using Acoustic Vector Sensors

• Józef Kotus
• Piotr Odya
• Maciej Szczodrak
• Bożena Kostek

2015

The aim of the presented paper was to obtain and visualize sound intensity distribution of radiated acoustic energy around the organ pipes. The experimental setup consisted of the multichannel acoustic vector sensor and the specialized Cartesian robot. Measurements were performed in free field with spatial resolution of 0.1 [m]. Two organ pipes, i.e. wooden and metal were measured during the ex-periment. The organ pipes were activated using the air-compressor. Thus, it was possible to obtain a long-term steady state response. The multichannel sound card was used to record data from the acoustic vector sensor. The results were processed in order to visualize sound intensity distribution around each pipe. Results obtained for both organ pipes are compared and discussed in the paper.

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(4-(Bis(4-Fluorophenyl)Methyl)Piperazin-1-yl)(Cyclohexyl)Methanone Hydrochloride (LDK1229): A New Cannabinoid CB1 Receptor Inverse Agonist from the Class of Benzhydryl Piperazine Analogs

• Mariam M. Mahmoud
• Teresa Olszewska
• Hui Liu
• Derek M. Shore
• Dow P. Hurst
• Patricia H. Reggio
• Dai Lu
• Debra A. Kendall

2015 MOLECULAR PHARMACOLOGY

Some inverse agonists of cannabinoid receptor type 1 (CB1) have been demonstrated to be anorectic antiobesity drug candidates. However, the first generation of CB1 inverse agonists, represented by rimonabant (SR141716A), otenabant, and taranabant, are centrally active, with a high level of psychiatric side effects. Hence, the discovery of CB1 inverse agonists with a chemical scaffold distinct from these holds promise for developing peripherally active CB1 inverse agonists with fewer side effects. We generated a new CB1 inverse agonist, (4-(bis(4-fluorophenyl)methyl)piperazin-1-yl)(cyclohexyl)methanone hydrochloride (LDK1229), from the class of benzhydryl piperazine analogs. This compound binds to CB1 more selectively than cannabinoid receptor type 2, with a Ki value of 220 nM. Comparable CB1 binding was also observed by analogs 1-[bis(4-fluorophenyl)methyl]-4-cinnamylpiperazine dihydrochloride (LDK1203) and 1-[bis(4-fluorophenyl)methyl]-4-tosylpiperazine hydrochloride (LDK1222), which differed by the substitution on the piperazine ring where the piperazine of LDK1203 and LDK1222 are substituted by an alkyl group and a tosyl group, respectively. LDK1229 exhibits efficacy comparable with SR141716A in antagonizing the basal G protein coupling activity of CB1, as indicated by a reduction in guanosine 5'-O-(3-thio)triphosphate binding. Consistent with inverse agonist behavior, increased cell surface localization of CB1 upon treatment with LDK1229 was also observed. Although docking and mutational analysis showed that LDK1229 forms similar interactions with the receptor as SR141716A does, the benzhydryl piperazine scaffold is structurally distinct from the first-generation CB1 inverse agonists. It offers new opportunities for developing novel CB1 inverse agonists through the optimization of molecular properties, such as the polar surface area and hydrophilicity, to reduce the central activity observed with SR141716A.

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5-Thiocyanato-2′-deoxyuridine as a possible radiosensitizer: electron-induced formation of uracil-C5-thiyl radical and its dimerization

• Magdalena Zdrowowicz
• Lidia Chomicz
• Michał Żyndul
• Paweł Wityk
• Janusz Rak
• Tyler Wiegand
• Cameron Hanson
• Amitava Adhikary
• Michael Sevilla

2015 PHYSICAL CHEMISTRY CHEMICAL PHYSICS

In this work, we have synthesized 5-thiocyanato-2′-deoxyuridine (SCNdU) along with the C6-deuterated nucleobase 5-thiocyanatouracil (6-D-SCNU) and studied their reactions with radiation-produced electrons. ESR spectra in γ-irradiated nitrogen-saturated frozen homogeneous solutions (7.5 M LiCl in H2O or D2O) of these compounds show that electron-induced S–CN bond cleavage occurs to form a thiyl radical (dU-5-S˙ or 6-D-U-5-S˙) and CN−via the initial π-anion radical (SCNdU˙−) intermediate in which the excess electron is on the uracil base. HPLC and LC-MS/MS studies of γ-irradiated N2-saturated aqueous solutions of SCNdU in the presence of sodium formate as a OH-radical scavenger at ambient temperature show the formation of the dU-5S-5S-dU dimer in preference to dU by about 10 to 1 ratio. This shows that both possible routes of electron-induced bond cleavage (dUC5–SCN and S–CN) in SCNdU˙− and dU-5-S˙ formation are preferred for the production of the σ-type uracilyl radical (dU˙) by 10 fold. DFT/M06-2x/6-31++G(d,p) calculations employing the polarizable continuum model (PCM) for aqueous solutions show that dU-5-S˙ and CN− formation was thermodynamically favored by over 15 kcal mol−1 (ΔG) compared to dU˙ and SCN− production. The activation barriers for C5–S and S–CN bond cleavage in SCNdU˙− amount to 8.7 and 4.0 kcal mol−1, respectively, favoring dU-5-S˙ and CN− formation. These results support the experimental observation of S–CN bond cleavage by electron addition to SCNdU that results in the formation of dU-5-S˙ and the subsequent dU-5S-5S-dU dimer. This establishes SCNdU as a potential radiosensitizer that could cause intra- and inter-strand crosslinking as well as DNA–protein crosslinking via S–S dimer formation.

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A 0.5-V bulk-driven voltage follower / DC level shifter and its application in class AB output stage

• Tomasz Kulej
• Grzegorz Blakiewicz

2015 INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS

A simple realization of a 0.5-V bulk-driven voltage follower/DC level shifter, designed in a 0.18um CMOS technology is presented in the paper. The circuit is characterized by large input and output voltage swings, and a DC voltage gain close to unity. The DC voltage shift between input and output terminals can be regulated in a certain interval around zero, by means of biasing current sinks. An application of the proposed voltage follower circuit for realization of a low-voltage class AB output stage has also been described in the paper. Finally, the operational amplifier exploiting the proposed output stage has been presented and evaluated in detail.

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A bound on the number of middle-stage crossbars in f-cast rearrangeable Clos networks

• Paweł Obszarski
• Marek Kubale

2015

In 2006 Chen and Hwang gave a necessary and sufficient condition under which a three-stage Clos network is rearrangeable for broadcast connections. Assuming that only crossbars of the first stage have no fan-out property, we give similar conditions for f-cast Clos networks, where f is an arbitrary but fixed invariant of the network. Such assumptions are valid for some practical switching systems, e.g. high-speed crossconnects. We also recognize the complexity status for a related routing problem. In our considerations we introduce the hypergraph edge coloring model, which is a suitable mathematical idealization for the three-stage Clos networks.

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A calibration model for gas sensor array in varying environmental conditions

• Paweł Kalinowski
• Karolina Sturgulewska
• Katarzyna Koc
• Piotr Jasiński
• Grzegorz Jasiński

2015 Elektronika : konstrukcje, technologie, zastosowania

Abstract: Gas-analyzing systems based on gas sensors, commonly referred to as electronic noses, are the systems which enable the recognition of volatile compounds in their working environment and provide the on-line results of analysis. The most commonly used type of sensors in such systems is semiconductor gas sensors. They are considered to be the most reliable in the long-term applications (more than 1 year), however, their signal tends to drift. Instability of semiconductor gas sensors is one of the most challenging issues to solve in order to get reliable e-nose systems. There are a few causes of drift phenomenon, like i.e. sensors poisoning or aging. On the other hand, drift-like effects are also connected with the influence of environmental parameters such as temperature, humidity or the parameters connected with measurement systems – such as gas flow rate in sensors measurement chamber. In the case of devices for air-quality monitoring, which are exposed to varying environmental conditions it is crucial to develop the robust sensor signals processing system, which is insensitive to the variation of environmental conditions. In this article we present the calibration model for an array of four semiconductor sensors which is able to eliminate the influence of temperature and gas flow rate effect from the sensor responses.

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A Centralized Reputation System for MANETs Based on Observed Path Performance

• Jerzy Konorski
• Karol Rydzewski

2015

A reputation system for MANETs is described that attempts to deduce nodal trustworthiness (forwarding behaviour) from observed end-to-end path performance. The trustworthiness deduction algorithm produces interval estimates and works well if node misbehaviour is not selec-tive with respect to traversing paths. Nodal reputation levels are next calculated in the spirit of generous tit-for-tat so as to best reflect momentary nodal trustworthiness. High-reputed sources are favoured when forwarding transit pack-ets (indirect reciprocity) and high-reputed paths are fa-voured by the multipath DSR. For a simplified network model and assuming the nodes are able to control their repu-tation levels with a view of a high source throughput, we find that high reputation may be costly to maintain. We examine an arising reputation game and conditions under which it produces a cooperation-stimulating Nash equilibrium.

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A city and a wind farm. Landscape perspective

• Aleksandra Sas-Bojarska

2015

The aim of the paper is to present the problems of the location of the wind farms in close neighbourhood to the historical cities, and the ways to minimize the potential landscape threats. The production of clean energy is obligatory in EU. In spite of how positive to the environment the wind energy production is, it may cause negative effects. The results of landscape studies of two towns in Poland prove that the location of such big constructions should be in some cases restricted. The crucial conclusion relates to the need for prediction of landscape threats, using the Environmental Impact Assessment procedure. The long-term, cumulative and irreversible landscape impacts have to be described, to precise effective mitigation measures. This is the only way to protect the unique character and touristic potential of historical cities and of the valuable historical landscapes.

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A commercial gas boiler fitted with the ORC module as perspective solution for households

• Dariusz Mikielewicz
• Jan Wajs
• Michał Bajor
• Jarosław Mikielewicz

2015

In this paper the applicability of the commercial gas boiler (De Dietrich DTG X23N) coupled with the laboratory prototype micro ORC setup was experimentally studied. The main objective was to determine the working fluid capability to obtain required temperatures of vapour prior to the turbine, attainable heat rates and efficiencies of the whole system. The boiler thermal power was 25 kW. Tests were carried out with a single stage turbine specifically designed and manufactured for the facility. Investigations show that the boiler was able to provide the saturated/superheated steam of ethanol as a working fluid at proper conditions needed in the ORC system and it can be utilized as a heat source in the domestic micro-CHP. The attained turbine power reached 1.5kW. In authors opinion it is very important conclusion for the research development on the domestic micro ORC.

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A Comparative Numerical Simulation Study of Turbulent Non-premixed CO/H2/N2 Syngas Jet Flames

• Michał Lewandowski
• Jacek Pozorski

2015

In the present work, numerical simulations of turbulent non-premixed syngas flame have been performed in Reynolds-Averaged Naver-Stokes turbulence approach using four turbulence-chemistry interaction models. To this aim, we used assumed beta PDF approach, Steady Laminar Flamelet model, Eddy Dissipation Concept and Partially Stirred Reactor model. Numerical results are compared and analysed with respect to two experiments from the TNF Workshop data sets. The most accurate predictions were obtained with the Partially Stirred Reactor model in OpenFOAM. Finally, we present a simulation of an industrial combustion chamber designed for low-calorific gas burning.

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A COMPARISON OF THE WIND SPECTRUM ACCORDING TO DIFFERENT METHODS - AN ORIGINAL PROJECT OF A BUILDING ON A CLIFF IN GDYNIA

• Monika Zielińska
• Karolina Zarychta

2015 Pełny tekst International Journal of Applied Mechanics and Engineering

The article presents numerical simulations of the dynamic wind loads on the structure of a building designed on a cliff in Gdynia. The results obtained from the two methods: Davenport’s and Karman’s are compared. The results allowed a comparison of the two methods, and they provided an answer to the question how a construction, designed in such an unusual condition of a cliff behaves under the influence of the gusting wind. The wind spectrum is presented and compared in both directions: of the X-axis and of the Y-axis. The dynamic calculations are carried out in the Abaqus software. The conducted numerical analyses compare the displacements in two points - at half height of the building and at the top - obtained by the two methods.

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A comprehensive evaluation of mimosa extract as a corrosion inhibitor on AA6060 alloy in acid rain solution: part I. Electrochemical AC methods

• Husnu Gerengi
• Agata Jażdżewska
• M. Kurtay

2015 JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY

The inhibition effect of mimosa extract on the corrosion of AA6060 aluminum alloy in acid rain solution was investigated by electrochemical impedance spectroscopy and dynamic electrochemical impedance spectroscopy (DEIS). All the studied electrochemical parameters showed good corrosion inhibitive characteristics with respect to the aluminum alloy in the tested solution. Inhibitor efficiency increased with the concentration and attained 45% at 2750 ppm. The advantage of DEIS as a tool for the investigation of corrosion inhibitor influence was discussed.

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A design framework and a digital toolset supporting the early-stage explorations of responsive kinetic building skin concepts

• Małgorzata Zboińska
• Kacper Radziszewski
• Jan Cudzik
• Robert Juchnevic

2015

In this paper we present the first phase of our research on the development of a framework for early-stage responsive kinetic building skin design. The aims of this study were: to formulate a methodological and instrumental basis for the construction of the framework, to conduct an initial pre-assessment of its features, and finally to provide the first example of how the framework could be applied in practice. Importantly, at this point our goal was not yet to indicate the framework's effectiveness, but rather focus on formulating its foundations. A pilot design experiment, aimed at the probing of the framework's characteristics, suggests the emergence of its two noteworthy features. Firstly, it allows to freely but at the same time also systematically explore six design aspects of responsive architecture: form, functionality, performance, kinetic behaviors, system mechanics and responsiveness. Secondly, it helps to explore these six aspects using diverse means: parametric models, digital simulations, computational analyses, physical models and interactive prototypes. These features suggest that the framework could be a valid and useful means of supporting designers in the complex task of creating architectural concepts of responsive kinetic structures.

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A dipole-driven path for electron and positron attachments to gas-phase uracil and pyrimidine molecules: a quantum scattering analysis

• Fabio Carelli
• F.a. Gianturco
• Jan Franz
• Mauro Satta

2015 EUROPEAN PHYSICAL JOURNAL D

Electron and positron scattering processes in the gas-phase are analysed for uracil and pyrimidine molecules using a multichannel quantum approach at energies close to threshold. The special effects on the scattering dynamics induced by the large dipole moments in both molecules on the spatial features of the continuum leptonic wavefunctions are here linked to the possible bound states of the Rydberg-like molecular anions or ‘positroned’ molecules which could be reached via further couplings with molecular internal degrees of freedom.

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A Goal-Oriented Error Estimator for Reduced Basis Method Modeling of Microwave Devices

• Michał Rewieński
• Adam Lamęcki
• Michał Mrozowski

2015 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS

This letter proposes a novel a-posteriori error estimator suitable for the reduced order modeling of microwave circuits. Unlike the existing error estimators based on impedance function residuals, the new one exploits the residual error associated with the computation of the scattering matrix. The estimator can be effectively used in the Reduced Basis Method (RBM) to automatically generate reduced-order models. The results of numerical experiments show that the new error estimator predicts the errors in the computed S-parameters more accurately than the other existing pproaches, and that it can be used to automate the generation of wideband reduced models

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