2017 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2017

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Direct Analysis of Samples of Various Origin and Composition Using Specific Types of Mass Spectrometry
- Hubert Byliński
- Jacek Gębicki
- Tomasz Dymerski
- Jacek Namieśnik
2017 Full text CRITICAL REVIEWS IN ANALYTICAL CHEMISTRY
One of the major sources of error that occur during chemical analysis utilizing the more conventional and established analytical techniques is the possibility of losing part of the analytes during the sample preparation stage. Unfortunately, this sample preparation stage is required to improve analytical sensitivity and precision. Direct techniques have helped to shorten or even bypass the sample preparation stage; and in this review, we comment of some of the new direct techniques that are mass-spectrometry based. The study presents information about the measurement techniques using mass spectrometry, which allow direct sample analysis, without sample preparation or limiting some pre-concentration steps. MALDI – MS, PTR – MS, SIFT – MS, DESI – MS techniques are discussed. These solutions have numerous applications in different fields of human activity due to their interesting properties. The advantages and disadvantages of these techniques are presented. The trends in development of direct analysis using the aforementioned techniques are also presented.
Direct brain stimulation modulates encoding states and memory performance in humans
- Youssef Ezzyat
- James E. Kragel
- John F. Burke
- Deborah F. Levy
- Anastasia Lyalenko
- Paul Wanda
- Logan O'Sullivan
- Katherine B. Hurley
- Stanislav Busygin
- Isaac Pedisich
- Michael R. Sperling
- Gregory Worrell
- Michał Tomasz Kucewicz
- Kathryn A. Davis
- Timothy H. Lucas
- Cory S. Inman
- Bradley C. Lega
- Barbara C. Jobst
- Sameer A. Sheth
- Kareem Zaghloul
- Michael J. Jutras
- Joel M. Stein
- Sandhitsu R. Das
- Richard Gorniak
- Daniel S. Rizzuto
- Michael J. Kahana
2017 Full text CURRENT BIOLOGY
People often forget information because they fail to effectively encode it. Here, we test the hypothesis that targeted electrical stimulation can modulate neural encoding states and subsequent memory outcomes. Using recordings from neurosurgical epilepsy patients with intracranially implanted electrodes, we trained multivariate classifiers to discriminate spectral activity during learning that predicted remembering from forgetting, then decoded neural activity in later sessions in which we applied stimulation during learning. Stimulation increased encoding-state estimates and recall if delivered when the classifier indicated low encoding efficiency but had the reverse effect if stimulation was delivered when the classifier indicated high encoding efficiency. Higher encoding-state estimates from stimulation were associated with greater evidence of neural activity linked to contextual memory encoding. In identifying the conditions under which stimulation modulates memory, the data suggest strategies for therapeutically treating memory dysfunction.
Direct measurements of odorous volatile organic compounds present in biosolids cakes by Proton Transfer Reaction – Mass Spectrometry Technique
- Hubert Byliński
- Radosław Barczak
- Tomasz Dymerski
- Jacek Gębicki
- Jacek Namieśnik
2017 Full text
This paper show the results of investigation of concentration of odorous chemical compounds emitted upon ageing of anaerobically stabilised biosolids that could contribute to the overall odour character of nuisance emissions. Biosolids samples from wastewater treatment plant were collected in spring time. Concentrations of volatile organic compounds using a US EPA flux hood and Proton Transfer Reaction-Time of Flight-Mass Spectrometry technique were monitored during three weeks. The concentrations of identified odorants were estimated from 0.23 ppm to 2.93 ppm. Increasing concentrations of all identified compoundswere observed after 10th day fromthe sampling days for two samples. It can be a consequence of biological process occurring in threeweek time in biosolids cakes.
Direction-of-Arrival Estimation Using an ESPAR Antenna with Simplified Beam Steering
- Łukasz Kulas
2017
In this paper, it has been shown, how electronically steerable parasitic array radiator (ESPAR) antenna, in which beam steering is done in a simple way, can be used for directionof- arrival (DoA) estimation of an unknown signal impinging the antenna. The concept is based on an ESPAR antenna having twelve parasitic elements, in which beam switching is realized by RF switches providing required loads to its parasitic elements. Numerical simulations indicate, that, by recording ESPAR antenna’s output for different directions of its main beam and applying the DoA estimation algorithm introduced in [6] that relies on received signal strength (RSS) values only, one can obtain estimation errors at the similar level as for the ESPAR antenna with six parasitic elements and steering involving DSP-based controller. By simplifying the way the directional main beam is switched in ESPAR antennas and by using RSS-based DoA estimation algorithm, one makes DoA estimation possible for inexpensive wireless sensor networks (WSN) nodes.
Disciplines and measures of information resilience
- Jacek Rak
- Magnus Jonsson
- David Hutchison
- James Sterbenz
2017
Communication networks have become a fundamental part of many critical infrastructures, playing an important role in information delivery in various failure scenarios triggered e.g., by forces of nature (including earthquakes, tornados, fires, etc.), technology-related disasters (for instance due to power blackout), or malicious human activities. A number of recovery schemes have been defined in the context of network resilience (with the primary focus on communication possibility in failure scenarios including access to a particular host, or information exchange between a certain pair of end nodes). However, because end-users are becoming more and more interested in information itself (regardless of its physical location in the network), it is appropriate to complement the well-defined framework of network resilience with one that addresses information resilience, and to introduce definitions of relevant disciplines and measures, as proposed in this paper.
Discrete and continuous fractional persistence problems – the positivity property and applications
- Jacky Cresson
- Anna Szafrańska
2017 Communications in Nonlinear Science and Numerical Simulation
In this article, we study the continuous and discrete fractional persistence problem which looks for the persistence of properties of a given classical (α=1) differential equation in the fractional case (here using fractional Caputo’s derivatives) and the numerical scheme which are associated (here with discrete Grünwald–Letnikov derivatives). Our main concerns are positivity, order preserving ,equilibrium points and stability of these points. We formulate explicit conditions under which a fractional system preserves positivity. We deduce also sufficient conditions to ensure order preserving. We deduce from these results a fractional persistence theorem which ensures that positivity, order preserving, equilibrium points and stability is preserved under a Caputo fractional embedding of a given differential equation. At the discrete level, the problem is more complicated. Following a strategy initiated by R. Mickens dealing with non local approximations, we define a non standard finite difference scheme for fractional differential equations based on discrete Grünwald–Letnikov derivatives, which preserves positivity unconditionally on the discretization increment. We deduce a discrete version of the fractional persistence theorem for what concerns positivity and equilibrium points. We then apply our results to study a fractional prey–predator model introduced by Javidi et al.
Displacement measurements during load testing of railway arch bridge
- Mikołaj Miśkiewicz
- Karolina Makowska
2017
The paper discusses issues concerning load tests carried out on a twin-track, arch railway bridge over the Martwa Wisla river in Gdansk. Currently, it is the bridge with the longest span in its class in Poland. The load-bearing structure consists of three no-hinge arches and an orthotropic deck suspended from them. The studies of the structure assumed the performing of static and dynamic tests. The paper presents the method for carrying out geodetic measurements during static tests as well as the analysis of obtained results. The main emphasis was on the total station measurements and precise leveling. Data was obtained concerning deck and arch displacements at controlled points and also on abutment subsidence. The tests allowed for both evaluation of the structural response under the load and verification of the safety of structure usage. The tests demonstrated that when the bridge is exposed to load, it behaves in accordance with the design assumptions and, therefore, the object can be put into operation.
Dissecting gamma frequency activities during human memory processing
- Michał Tomasz Kucewicz
- Brent M. Berry
- Vaclav Kremen
- Benjamin H. Brinkmann
- Michael R. Sperling
- Barbara C. Jobst
- Robert E. Gross
- Bradley Lega
- Sameer A. Sheth
- Joel M. Stein
- Sandhitsu R. Das
- Richard Gorniak
- S. Matthew Stead
- Daniel S. Rizzuto
- Michael J. Kahana
- Gregory A. Worrell
2017 Brain: A Journal of Neurology
Gamma frequency activity (30-150 Hz) is induced in cognitive tasks and is thought to reflect underlying neural processes. Gamma frequency activity can be recorded directly from the human brain using intracranial electrodes implanted in patients undergoing treatment for drug-resistant epilepsy. Previous studies have independently explored narrowband oscillations in the local field potential and broadband power increases. It is not clear, however, which processes contribute to human brain gamma frequency activity, or their dynamics and roles during memory processing. Here a large dataset of intracranial recordings obtained during encoding of words from 101 patients was used to detect, characterize and compare induced gamma frequency activity events. Individual bursts of gamma frequency activity were isolated in the time-frequency domain to determine their spectral features, including peak frequency, amplitude, frequency span, and duration. We found two distinct types of gamma frequency activity events that showed either narrowband or broadband frequency spans revealing characteristic spectral properties. Narrowband events, the predominant type, were induced by word presentations following an initial induction of broadband events, which were temporally separated and selectively correlated with evoked response potentials, suggesting that they reflect different neural activities and play different roles during memory encoding. The two gamma frequency activity types were differentially modulated during encoding of subsequently recalled and forgotten words. In conclusion, we found evidence for two distinct activity types induced in the gamma frequency range during cognitive processing. Separating these two gamma frequency activity components contributes to the current understanding of electrophysiological biomarkers, and may prove useful for emerging neurotechnologies targeting, mapping and modulating distinct neurophysiological processes in normal and epileptogenic brain.
Dissociation of 2-oxopropanoic acid by low energy electrons
- Mateusz Zawadzki
- Jaroslav Kočišek
- Juraj Fedor
2017 Full text Journal of Physics : Conference Series
Electron attachment to molecular target can lead to a variety of negative fragment ions. We experimentally probe the main dissociative electron attachment (DEA) channels in 2-oxopropanoic acid (CH3 - CO - COOH) - an important trace component in the Earth's atmosphere. In our studies we utilise nearly mono-energetic electrons at electron energies from 0 eV up to 15 eV.
Distinction of citrus fruits based on their volatile composition using the electronic nose
- Dominika Pudlak
- Martyna Lubinska-Szczygeł
- Tomasz Dymerski
- Jacek Namieśnik
2017
The aim of the study was to analyze the volatile fraction of the citrus fruit using an electronic nose device integrated with ultrafast gas chromatography. The subjects were Citrus aurantifolia, Fortunella margarita Swingle and Citrus × floridana. The chromatographic data obtained were analyzed by means of chemometric methods: PCA and SQC. On the basis of the charts obtained, it is possible to distinguish the fruits tested on the basis of their botanical origin and to determine the differences between the individual fruit samples.
Distinction of clenbuterol intake from drug or contaminated food of animal origin in a controlled administration trial – the potential of enantiomeric separation for doping control analysis
- Maria K. Parr
- Marco Blokland
- Franz Liebetrau
- Alexander Schmidt
- Thijs Meijer
- Mijo Stanic
- Dorota Kwiatkowska
- Emilia Waraksa
- Saskia Sterk
2017 Food Additives and Contaminants Part A-Chemistry Analysis Control Exposure& Risk Assessment
The differentiation of clenbuterol abuse and unintentional ingestion by contaminated meat is crucial with respect to the valuation of an adverse analytical finding in human sports doping control. The proportion of the two enantiomers of clenbuterol may serve as potential discriminating parameter. For the determination of the individual enantiomers, specific methods were developed and validated for the different matrices under investigation based on chiral chromatography coupled to tandem mass spectrometry. Data from the administration of clenbuterol from a pharmaceutical preparation and from cattle meat and liver containing residues to humans are presented. A shift in the proportion of the enantiomers in cattle meat is detected and this signature is also found in human urine after ingestion. Thus, an altered enantiomeric composition of clenbuterol may be used to substantiate athletes’ claims following adverse analytical findings in doping control. However, in meat, the enantiomeric composition was found to be highly variable. Species as well as tissue dependent variances need to be considered in interpreting enantiomer discrimination. Post administration urine from a controlled experiment comparing the administration of racemic clenbuterol from a registered pharmaceutical preparation and the administration of residue containing meat and liver from treated animals (nonracemic mixture) is reported. Furthermore doping control samples from Mexican U17 World Championship 2011 of the Fédération Internationale de Football Association (FIFA), with adverse analytical findings for clenbuterol, were reanalysed
Distortional buckling of thin-walled columns of closed quadratic cross-section
- Czesław Szymczak
- Marcin Kujawa
2017 THIN-WALLED STRUCTURES
The elastic stability of axially compressed column related to the cross-section distortion is investigated. Two kinds of closed quadratic cross-sections are taken into consideration with internal walls and without it. The governing differential equation is derived with aid of the principle of stationary total potential energy. The critical loads for the simply supported columns are found in an analytical form and compared with the FEM solution. Sufficient accuracy of the results is worth of noticing.
Distributed NVRAM Cache – Optimization and Evaluation with Power of Adjacency Matrix
- Artur Malinowski
- Paweł Czarnul
2017
In this paper we build on our previously proposed MPI I/O NVRAM distributed cache for high performance computing. In each cluster node it incorporates NVRAMs which are used as an intermediate cache layer between an application and a file for fast read/write operations supported through wrappers of MPI I/O functions. In this paper we propose optimizations of the solution including handling of write requests with a synchronous mode, additional modes preventing data preloading from a file and synchronization on file close if the solution is used as temporary cache only. Furthermore, we have evaluated the solution for a real application that computes powers of an adjacency matrix of a graph in parallel. We demonstrated superiority of our solution compared to a regular MPI I/O implementation for various powers and numbers of graph nodes. Finally, we presented good scalability of the solution for more than 600 processes running on a large HPC cluster.
Distribution of relaxation times as a method of separation and identification of complex processes measured by impedance spectroscopy
- Justyna Bartoszek
- Yi-Xin Liu
- Jakub Karczewski
- Sea-Fue Wang
- Aleksander Mroziński
- Piotr Jasiński
2017
Impedance spectroscopy is one of the most commonly performed measurements to characterize electronic and electrochemical systems. Impedance spectra have limited resolution and many different processes may overlap what could be the reason of obstructions in its proper later analysis. Up to date, there are three approaches to solve this problem: examining impedance spectra itself, fitting spectra with equivalent circuits, and calculating the distribution of relaxation times (DRT). The latter method does not require any model or further knowledge about the system. As a result of DRT calculation, a plot containing relatively narrow peaks related to relaxation process of measured system is obtained. Namely, the position of the peak is related to time constant of the process, while the area under the peak to relaxation resistance. The aim of this work is to test available fitting functions to calculate area under a peak for previously prepared model containing different equivalent circuit elements. Obtained results are validated using exact formulas describing distribution of relaxation times for mentioned elements.
DŁUGOTRWAŁE BEZROBOCIE W POLSCE W LATACH 2000-2015 NA TLE WYBRANYCH KRAJÓW UNII EUROPEJSKIEJ
- Aleksandra Podwysocka
2017 Full text Acta Universitatis Nicolai Copernici ZARZĄDZANIE
DŁUGOTRWAŁE BEZROBOCIE JEST POTWIERDZENIEM ISTNIENIA TRWAŁEJ NIERÓWNOWAGI NA RYNKU PRACY. SKUTKUJE UJEMNYMI SKUTKAMI W SFERZE EKONOMICZNEJ, SPOŁECZNEJ I INDYWIDUALNEJ. CELEM OPRACOWANIA JEST PRZEDSTAWIENIE ZMIAN W DŁUGOTRWAŁYM BEZROBOCIU W POLSCE, PREZENTACJA I OCENA NA TLE WYBRANYCH KRAJÓW UNII EUROPEJSKIEJ W LATACH 2000-2015. DO BADAŃ WYKORZYSTANO OGÓLNODOSTĘPNE MATERIAŁY STATYSTYCZNE I ELEMENTY STATYSTYKI OPISOWEJ. PONADTO DOKONANO PRZEGLĄDU LITERATURY POŚWIĘCONEJ ZAGADNIENIOM DŁUGOTRWAŁEGO BEZROBOCIA.
DMI measurements impact on a position estimation with lack of GNSS signals during Mobile Mapping
- Katarzyna Bobkowska
- Grzegorz Nykiel
- Paweł Tysiąc
2017 Full text Journal of Physics : Conference Series
Nowadays, Mobile Laser Scanning is common in use in addition to geodesy measurements. The data which are provided by the system characterizes with high precision and flexibility. To precise mapping, the accuracy of the data should be maintained. In Poland, according to the minister’s dispositions, the accuracy of the data should not exceeded 10 cm. With fully operated system it is easy to uphold, but there is a situation when a signal from an INS is not enough to preserve it. This paper is presenting the solution of a DMI use in Mobile Laser Scanning measurements as the support for position estimation during lack of satellites signal situation when the vehicle with the platform was entered the tunnel. To comparison the results a several of entrances was performed. This research helps understand the use of DMI in mobile data acquisition in different acquiring situations.
Do górskiego żródła
- Wojciech Strzelecki
2017
Wystawa indywidualna
Dobór geotekstyliów i wyrobów pokrewnych pełniących funkcję zbrojenia w budownictwie komunikacyjnym – wybrane problemy inżynierskie
- Grzegorz Horodecki
- Angelika Duszyńska
2017 Full text Magazyn Autostrady
Z uwagi na odpowiedzialność uczestników procesu budowlanego za realizowane inwestycje komunikacyjne w coraz dłuższym horyzoncie czasowym, celowe wydaje się zwrócenie uwagi na zagadnienia związane z obserwowanymi niestety nadal problemami dotyczącymi umiejętności odróżniania poszczególnych rodzajów geosyntetyków oraz weryfikacji wymaganych w projekcie tzw. technicznych parametrów istotnych (np. wytrzymałość długoterminowa w przypadku wyrobów pełniących funkcję zbrojenia).
DOBÓR PRZEKROJU ŻYŁ POWROTNYCH W KABLACH ŚREDNIEGO NAPIĘCIA
- Marek Olesz
- Radosław Sawicz
2017 Full text Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
W referacie przedstawiono zasady doboru przekroju żył powrotnych w kablach średniego napięcia (SN) z uwzględnieniem zwarć jednofazowych i dwufazowych z udziałem ziemi. Przeprowadzona analiza wskazuje na możliwość zmniejszenia obowiązującego dotychczas przekroju żyły powrotnej 50 mm2, co wprowadzono do stosowania w sieci rozdzielczej w Energa Operator SA.
Dobór rodzaju funkcjonalnego PG asfaltów według metody Superpave w zależności od stref klimatycznych w Polsce.
- Marek Pszczoła
- Dawid Ryś
- Piotr Jaskuła
2017 Full text Nawierzchnie Asfaltowe
Obecnie w Polsce, podobnie jak i w pozostałych krajach Unii Europejskiej, asfalty drogowe są badane i klasyfikowane głównie w oparciu o wynik oznaczenia penetracji w temperaturze 25ºC niezależnie od warunków klimatycznych, w jakich potem mają one pracować w nawierzchni drogowej. Pod koniec ubiegłego wieku w ramach amerykańskiego programu SHRP opracowano i wdrożono nowy system klasyfikacji asfaltów. Ideą wprowadzenia nowego systemu była potrzeba lepszego dostosowania metod badań oraz wymagań dla asfaltów drogowych do rzeczywistych warunków, w jakich pracują te asfalty w nawierzchniach drogowych.