2018 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2018

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PTR-MS and GC-MS as complementary techniques for analysis of volatiles: A tutorial review
- Tomasz Majchrzak
- Wojciech Wojnowski
- Martyna Lubinska-Szczygeł
- Anna Różańska
- Jacek Namieśnik
- Tomasz Dymerski
2018 ANALYTICA CHIMICA ACTA
This tutorial review is a critical commentary on the combined use of two instrumental analytical techniques, namely GC-MS and PTR-MS. The first mention of such an analytical approach likely appeared after the year 2000 and despite many advantages, it has not been applied very often. Therefore, the aim of this article is to elaborate on the concept of their combined use and to provide a curse tutorial for those considering taking such an approach. The issue of complementarity was raised in a broad sense of this term. Special emphasis was placed on indicating the possibilities of complementary utilization of GC-MS and PTR-MS and presenting the advantages and disadvantages as well as the current application of these techniques when used together.
Pupil size reflects successful encoding and recall of memory in humans
- Michał Tomasz Kucewicz
- Jaromir Dolezal
- Vaclav Kremen
- Brent M. Berry
- Laura R. Miller
- Abigail L. Magee
- Vratislav Fabian
- Gregory A. Worrell
2018 Full text Scientific Reports
Pupil responses are known to indicate brain processes involved in perception, attention and decision-making. They can provide an accessible biomarker of human memory performance and cognitive states in general. Here we investigated changes in the pupil size during encoding and recall of word lists. Consistent patterns in the pupil response were found across and within distinct phases of the free recall task. The pupil was most constricted in the initial fixation phase and was gradually more dilated through the subsequent encoding, distractor and recall phases of the task, as the word items were maintained in memory. Within the final recall phase, retrieving memory for individual words was associated with pupil dilation in absence of visual stimulation. Words that were successfully recalled showed significant differences in pupil response during their encoding compared to those that were forgotten – the pupil was more constricted before and more dilated after the onset of word presentation. Our results suggest pupil size as a potential biomarker for probing and modulation of memory processing.
Quadratic stochastic operators on Banach lattices
- Michał Badocha
- Wojciech Bartoszek
2018 Full text POSITIVITY
We study the convergence of iterates of quadratic stochastic operators that are mean monotonic. They are defined on the convex set of probability measures concentrated on a weakly compact order interval S = [0, f] of a fixed Banach lattice F. We study their regularity and identify the limits of trajectories either as the “infimum” or “supremum” of the support of initial distributions.
Qualitative and Quantitative Analysis of Selected Tonic Waters by Potentiometric Taste Sensor With All-Solid-State Electrodes
- Ewa Marjańska
- Maria Szpakowska
2018 IEEE SENSORS JOURNAL
Taste sensor with five all-solid-state electrodes (ASSE) III (third version) was used for qualitative and quantitative analysis of selected tonic waters (J.Gasco, Kinley, Jurajski, Jurajski with citrus flavor, Carrefour, Schweppes Indian Tonic, and Schweppes Bitter Lemon). The results obtained by this taste sensor analyzed with principal component analysis, agglomerative hierarchical clustering methods show that this sensor can be applied for discrimination of tonic waters with respect to their composition. Based on sensor's results, two models for prediction of the content of quinine hydrochloride and total saccharides in selected tonic waters were developed using multivariate linear regression. The results obtained by this analysis in comparison to nominal data (experimentally determined and obtained from manufacturers') are consistent (range of 0.1%-1.8%). It means that taste sensor with five ASSE III may be a useful tool for the qualitative and quantitative analysis of selected tonic waters.
Quality Assurance and Quality Control in the Analytical Chemical Laboratory. A practical approach : Second edition
- Piotr Konieczka
- Jacek Namieśnik
2018
The second edition defines the tools used in QA/QC, especially the application of statistical tools during analytical data treatment. Clearly written and logically organized, it takes a generic approach applicable to any field of analysis. The authors begin with the theory behind quality control systems, then detail validation parameter measurements, the use of statistical tests, counting the margin of error, uncertainty estimation, traceability, reference materials, proficiency tests, and method validation. New chapters cover internal quality control and equivalence method, changes in the regulatory environment are reflected throughout, and many new examples have been added to the second edition.
Quality of limes juices based on the aroma and antioxidant properties
- Martyna Lubinska-Szczygeł
- Anna Różańska
- Jacek Namieśnik
- Tomasz Dymerski
- Rajamohamed Beema Shafreen
- M. Weisz
- Aviva Ezra
- Shela Gorinstein
2018 FOOD CONTROL
Kaffir (Citrus hystrix) and Key (Citrus aurantifolia) limes juices were investigated and compared. Two dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOF-MS) was applied to assess the botanical origin of Kaffir and Key limes juices, based on volatile substances. The biggest differences in the contents of selected terpenes in Kaffir and Key limes occur in chemical compounds such as Limonene, Citral, Terpinen-4-ol. Limonene concentration is almost 8 times higher in the Key lime volatile fraction than in Kaffir lime. The difference in concentration of Citral in Kaffir lime is almost 20 mg/kg lower than in Key lime. Higher concentration of Terpinen-4-ol was noted in Kaffir lime samples and the content was almost 20 times higher. The concentrations of α-Pinene, Citronellal, Camphene, Nerol, trans-Geraniol and β-Pinene are at similar levels in the volatile fraction of both fruits. Bioactive substances (polyphenols, flavonoids, tannins and flavanols) and the values of antioxidant capacities by four radical scavenging assays (DPPH, CUPRAC FRAP, ABTS) were determined and compared in water and methanol extracts in Kaffir and Key limes juices. The bioactivity of Kaffir lime differ significantly in water extracts in comparison with Key lime juices. The 1H NMR shifts in methanol and chloroform extracts showed some differences in aromatic region between the two varieties of lime juices. Terpinen-4-ol for Kaffir lime and Citral for Key lime were used as potential markers. The GC×GC-TOF-MS allows better separation of substances originating from complex matrices than one-dimensional chromatography, based on improved resolution, increased peak capacity and unique selectivity. The possible falsification of mentioned juices can be detected by the use of GC×GC-TOF-MS, antioxidant assays and NMR shifts.
Quantitative study of free convective heat losses from thermodynamic partitions using Thermal Imaging
- Witold Lewandowski
- Michał Ryms
- Hubert Denda
2018 ENERGY AND BUILDINGS
The following paper presents a simple method of determining the presence, distribution and values of heat losses from external building walls as thermodynamic partitions using a Thermal Imaging Camera (TIC). According to Fourier's equation, the value of heat loss is proportional to the temperature gradient ∂t/∂y|y=0 in air in the y direction perpendicular to the heated surface. Unfortunately, air temperature cannot be measured with a TIC, as gases do not emit thermal radiation. It is therefore suggested that a grid placed vertically in the air and perpendicularly to the heated surface should be used as a detector of temperature field. Warmed by convective air flows, such a grid becomes a source of infrared radiation. The temperature distribution reproduced on the grid constructed from thin strands of a low thermal conductivity material is sufficiently distinct and sharp to be recorded with a TIC. The correctness of the TIC method has been tested in laboratory conditions on the example of a vertical heating plate, as well as in real-life conditions – on a single pane of glass serving as a building partition. When compared to the works of other authors, the result obtained as Nu = 0.571∙〖Ra〗^0.25 relation reveals a satisfactory correlation for the heating plate, while estimated temperature distributions and heat fluxes from the room to the surface of thermodynamic partition wall Qloss,conv,in and on the outside of the building Qloss,conv,ext successfully and quite precisely correlate (5−7% for both internal and external sides) with theoretical calculations. Therefore, the TIC method proposed in this paper can significantly extend the range of application of TICs in energy audits, especially for buildings.
Quantum dots conjugates with unsymmetrical bisacridines enhance cytotoxicity of these antitumor compounds in lung cancer cells and have protecting effects on normal cells
- Joanna Pilch
- Monika Pawłowska
- Piotr Bujak
- Anna M. Nowicka
- Ewa Augustin
2018 EUROPEAN JOURNAL OF CANCER
Background: In recent years, with the rapid development of nanotechnology and its extensive applications in the medicine, nanocarriers for anticancer drug delivery have gained a great importance. Spherical semiconductor nanocrystals, frequently called quantum dots (QDs) are very attractive nanomaterials for bioimaging applications and they possess properties as potential candidates for drug carrier. Unsymmetrical bisacridines (UAs), synthesized in our laboratory, EP 15461518.1, 2017, are the promising antitumor agents with high cytotoxic activity against many experimental cellular and tumor models (colon, lung, pancreatic, breast, prostate). Here, we investigated whether QDs conjugated with unsymmetrical bisacridines affect cytotoxicity of these compounds in human lung carcinoma cells as well as normal lung fibroblasts. Results: Both compounds exhibited high cytotoxicity against lung cancer H460 cells (IC80: 0.035 µM for C-2028 and 0.273 µM for C-2045), being less active against normal lung fibroblast MRC-5 (IC80: 0.47 µM for C-2028, 0.45 µM for C-2045). C-2028 and C-2045 conjugated with QDred and QDgreen decreased IC80 values of both compounds (QDred: 1.5 and 1.9 fold, QDgreen: 1.2 and 1.3 fold, respectively). Interestingly, UAs conjugated with both red and green QD were much less cytotoxic against normal MRC-5 cells. IC80 value for QDred-C-2028 increased 22 fold, QDred-C-2045 28 fold, QDgreen-C-2028 2.5 fold and QDgreen-C-2045 11 fold. Moreover, QDs alone did not influence cancer and normal cells proliferation. Comparing the obtained values from voltammetric measurements with the maximum amount of UAs compounds immobilized at QD surface one can conclude that the efficiency of the nanoconjugates synthesis was higher for QDred nanocrystals. Conclusions: Our results indicate that conjugation of unsymmetrical bisacridines with QDs improves drugs cytotoxicity in lung cancer cells and protects normal lung fibroblast from drugs action. These effects were more pronounced in the case of QDred, which were more effectively loaded by bisacridines.
Quasirelativistic potential energy curves and transition dipole moments of NaRb
- Marcin Wiatr
- Patryk Jasik
- Tymon Kilich
- Józef Eugeniusz Sienkiewicz
- Hermann Stoll
2018 Full text CHEMICAL PHYSICS
We report on extensive calculations of quasi-relativistic potential energy curves and, for the first time, transition dipole moments including spin-orbit and scalar-relativistic effects of the NaRb molecule. The calculated curves of the 0+, 0-, 1, 2 and 3 molecular states correlate for large internuclear separation with the fourteen lowest atomic energies up to the Na(3s ^2S_{1/2}) + Rb(7s ^2S_{1/2}) atomic limit. Several new features of the potential energy curves have been found.
Radio Simulcasting at a Glance: a New Look at Broadcasting and Streaming Services
- Przemysław Falkowski-Gilski
2018
Radio is by far one of the most popular and accessible medium. With its availability it attracts listeners all around the world. There are numerous ways of delivering content to consumers. The present situation is characterized by the convergence of acoustics, computer science and telecommunications. This paper reviews the current status of radio broadcasting and streaming services. It describes a subjective study concerning different ways of providing content through analog and digital terrestrial, as well as Internet networks. It analyzes the possibilities and limitations related with each technology, from an economic and technological point of view, as well as resource sharing mechanisms.
Radioisotope measurement of selected parameters of liquid-gas flow using single detector system
- Marcin Zych
- Robert Hanus
- Marek Jaszczur
- Volodymyr Mosorov
- Dariusz Świsulski
2018 Full text EPJ Web of Conferences
To determine the parameters of two-phase flows using radioisotopes, usually two detectors are used. Knowing the distance between them, the velocity of the dispersed phase is calculated based on time delay estimation. Such a measurement system requires the use of two gamma-ray sealed sources. But in some situations it is also possible to determine velocity of dispersed phase using only one scintillation probe and one gamma-ray source. However, this requires proper signal analysis and prior calibration. This may also cause larger measurement errors. On the other hand, it allows measurements in hard to reach areas where there is often no place for the second detector. Additionally, by performing a previous calibration, it is possible to determine the void fraction or concentration of the selected phase. In this work an autocorrelation function was used to analyze the signal from the scintillation detector, which allowed for the determination of air velocities in slug and plug flows with an accuracy of 8.5%. Based on the analysis of the same signal, a void fraction with error of 15% was determined.
Radioisotope measurements of the liquid-gas flow in the horizontal pipeline using phase method
- Robert Hanus
- Marcin Zych
- Marek Jaszczur
- Leszek Petryka
- Dariusz Świsulski
2018 Full text EPJ Web of Conferences
The paper presents application of the gamma-absorption method to a two-phase liquid-gas flow investigation in a horizontal pipeline. The water-air mixture was examined by a set of two Am-241 radioactive sources and two NaI(Tl) scintillation probes. For analysis of the electrical signals obtained from detectors the cross-spectral density function (CSDF) was applied. Results of the gas phase average velocity measurements for CSDF were compared with results obtained by application of the classical cross-correlation function (CCF). It was found that the combined uncertainties of the gas-phase velocity in the presented experiments did not exceed 1.6% for CSDF method and 5.5% for CCF.
Radiowe łącze ruchome do szybkiej transmisji danych multimedialnych dla systemu kontroli obszaru
- Ryszard Katulski
2018 Full text Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
Przedstawiono działalność naukowo-badawczą Katedry Systemów i Sieci Radiokomunikacyjnych Politechniki Gdańskiej w dziedzinie obronności bezpieczeństwa publicznego na przykładzie zagadnienia zastosowania ruchomego kanału radiowego o dużej przepływności do transmisji w czasie rzeczywistym danych multimedialnych. Krótko przeanalizowano przydatność do tego elementów techniki transmisji danych stosowanych w rozwiązaniach komercyjnych. Opisano wykonane badania wstępne i scharakteryzowano ich wyniki pod względem wykorzystania w projektowanym łączu radiowym. Przedstawiono opracowaną innowacyjną koncepcję takiego łącza i wybrane wyniki badań w rzeczywistych warunkach eksploatacyjnych zaprojektowanego i wykonanego demonstratora technologicznego.
RANS-based design optimization of dual-rotor wind turbines
- Andrew Thelen
- Leifur Leifsson
- Anupam Sharma
- Sławomir Kozieł
2018 ENGINEERING COMPUTATIONS
Purpose An improvement in the energy efficiency of wind turbines can be achieved using dual rotors. Because of complex flow physics, the design of dual-rotor wind turbines (DRWTs) requires repetitive evaluations of computationally expensive partial differential equation (PDE) simulation models. Approaches for solving design optimization of DRWTs constrained by PDE simulations are investigated. The purpose of this study is to determine design optimization algorithms which can find optimal designs at a low computational cost. Design/methodology/approach Several optimization approaches and algorithms are compared and contrasted for the design of DRWTs. More specifically, parametric sweeps, direct optimization using pattern search, surrogate-based optimization (SBO) using approximation-based models and SBO using kriging interpolation models with infill criteria are investigated for the DRWT design problem. Findings The approaches are applied to two example design cases where the DRWT fluid flow is simulated using the Reynolds-averaged Navier−Stokes (RANS) equations with a two-equation turbulence model on an axisymmetric computational grid. The main rotor geometry is kept fixed and the secondary rotor characteristics, using up to three variables, are optimized. The results show that the automated numerical optimization techniques were able to accurately find the optimal designs at a low cost. In particular, SBO algorithm with infill criteria configured for design space exploitation required the least computational cost. The widely adopted parametric sweep approach required more model evaluations than the optimization algorithms, as well as not being able to accurately find the optimal designs. Originality/value For low-dimensional PDE-constrained design of DRWTs, automated optimization algorithms are essential to find accurately and efficiently the optimal designs. More specifically, surrogate-based approaches seem to offer a computationally efficient way of solving such problems.
Rapid assessment of the authenticity of limequat fruit using the electronic nose and gas chromatography coupled with mass spectrometry
- Martyna Lubinska-Szczygeł
- Dominika Pudlak
- Tomasz Dymerski
- Jacek Namieśnik
2018 Full text MONATSHEFTE FUR CHEMIE
Citrus fruits are very popular food products. There are many species and varieties of them. There are also documented cases of some citrus fruits causing a severe allergic reaction. Some species of the citrus fruits, especially hybrid ones show a reduced allergenic effect due to the lack of seeds. There is a need for rapid methods for evaluation of citrus’ botanical origin. During research, the headspace of three citrus fruits Citrus Aurantifolia, Citrus japonica, and Citrus × floridana was analysed using electronic nose based on ultrafast gas chromatography and gas chromatography with mass spectrometry. In the paper, two approaches were compared. The usefulness of an electronic nose to control the quality of hybrids was demonstrated. The results obtained during ultrafast gas chromatography analyses were subjected to statistical analysis. Four chemometric methods namely: principal component analysis (PCA), discriminant function analysis (DFA), soft independent modeling of class analogies (SIMCA), statistical quality control (SQC) were used to distinguish between limequat and its parent fruits. Electronic nose combined with chemometrics is a novel analytical tool for hybrid fruits’ classification due to their botanical origin. It can supplement established techniques by providing results in a short time and at a low cost.
Rapid design closure of linear microstrip antenna array apertures using response features
- Sławomir Kozieł
- Ogurtsov Stanislav
2018 IEEE Antennas and Wireless Propagation Letters
A simple yet reliable approach to a rapid design closure of linear antenna array apertures at the electromagnetic (EM)-simulation level is proposed. Our methodology exploits an underlying array factor (AF) model suitably corrected by means of characteristic points (angles and levels) of the radiation pattern of the EM model of the antenna array aperture. This conveniently allows for controlling both the side lobe levels and the main beam width of the radiation pattern. The surrogate model constructed using the characteristic points is iteratively updated and re-optimized within the trust-region-embedded gradient-search framework. Considerable design speedup is achieved by exploiting correlations between the AF and EM models. The proposed algorithm is demonstrated using 12, 24, and 36-element linear microstrip antenna array apertures with the optimum designs obtained at the cost of a few EM simulations of the respective structures.
Rapid design closure of microwave components by means of feature-based optimization and adjoint sensitivities
- Sławomir Kozieł
- Adrian Bekasiewicz
2018 Full text INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING
In this article, fast design closure of microwave components using feature-based optimization (FBO) and adjoint sensitivities is discussed. FBO is one of the most recent optimization techniques that exploits a particular structure of the system response to “flatten” the functional landscape handled during the optimization process, which leads to reducing its computational complexity. When combined with gradient-based search involving adjoint sensitivities, the design cost becomes even lower, allowing us to find the optimum design using just a few electromagnetic (EM) simulations of the structure at hand. Here, operation and performance of the algorithm is demonstrated using a waveguide filter and a miniaturized microstrip rat-race coupler (RRC). Comparative studies indicate considerable savings that can be achieved even compared with adjoint-based gradient search. In case of RRC, numerical results are supported by experimental validation.
Rapid Design Tuning of Miniaturized Rat-Race Couplers Using Regression-Based Equivalent Network Surrogates
- Piotr Kurgan
- Sławomir Kozieł
- John W. Bandler
2018
A simple technique for fast design tuning of compact rat-race couplers is presented. Our approach involves equivalent circuit representation, corrected by nonlinear functions of frequency with coefficients extracted through nonlinear regression. At the same time, the tuning process connects two levels of coupler representation: EM simulation of the entire circuit and re-optimization of the coupler building blocks (slow-wave cells and folded transmission lines) with specifications obtained by appropriate manipulation of the corrected network model. The latter is driven by the necessity of accounting for EM cross-couplings within the coupler that result in performance degradation. Demonstration examples of a miniaturized rat-race coupler indicate that rapid and reliable design closure (at a cost of two or three coupler simulations) can be accomplished even for strong cross-couplings within the structure.
Rapid Evaluation of Poultry Meat Shelf Life Using PTR-MS
- Wojciech Wojnowski
- Tomasz Majchrzak
- Piotr Szweda
- Tomasz Dymerski
- Jacek Gębicki
- Jacek Namieśnik
2018 Full text Food Analytical Methods
The use of proton transfer reaction mass spectrometry (PTR-MS) for freshness classification of chicken and turkey meat samples was investigated. A number of volatile organic compounds (VOCs) were selected based on the correlation (> 95%) of their concentration during storage at 4 °C over a period of 5 days with the results of the microbial analysis. In order to verify if the selected compounds are not sample-specific, a number of samples sourced from various retailers were classified using the concentration of these compounds in the samples’ volatile fraction as input variables. The classification was performed using the support vector machines (SVM) supervised pattern recognition algorithm. It was concluded that it is possible to evaluate the shelf life of meat samples obtained from the same source based on the results of a prior analysis. The PTR-MS fingerprint approach might supplement the currently used methods of shelf life evaluation of poultry due to the short time and nondestructive nature of measurement and ease of quantitative analysis.
Raport z I etapu badań eksperymentalnych żelbetowych płyt prefabrykowanych z łącznikami balkonowymi
- Maciej Niedostatkiewicz
- Paweł Piotrkowski
- Jarosław Kondrat
- Maciej Tomasz Solarczyk
2018
Niniejsze opracowanie stanowi raport z I etapu badań prefabrykowanych zestawów balkonowych o wymiarach (szerokość × długość × wysokość): 2,0 m × 2,78 m × 0,186 m (w spadku do 0,17 m) składających się z żelbetowych płyt połączonych ze sobą łącznikami balkonowymi typu 1 lub typu 2.