Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Pokaż publikacje z roku

Ostatnie pozycje

  • Determination of heavy metals in eyeshadows from China
    • Lesław Świerczek
    • Bartłomiej Cieślik
    • Adrianna Matysiak
    • Piotr Konieczka
    2019 Pełny tekst MONATSHEFTE FUR CHEMIE

    Personal care products and cosmetics are used daily by many people, causing local exposure to certain chemical substances through the application directly inside the oral cavity, on the skin, lips, eyes, and mucosa. Eyeshadows are among the most commonly used types of cosmetics. According to scientifc reports, they may contain heavy metals, especially in non-original products. The exposure to said heavy metals may cause local skin irritation, sensitization, and allergy. Due to the fact that they are applied around the eyes, where the skin is relatively thin, it is likely that heavy metals can get into the bloodstream which may pose a threat to consumers’ health. In the described research, the analysis of eyeshadows from two palettes of generic alternatives to the original eyeshadows was presented. The determination of Zn, Ni, Cd, Cu, and Pb was conducted using atomic absorption spectrometry. Based on the analysis of the obtained results, it was shown that the content of some heavy metals in generic eyeshadows exceeds the acceptable standards.

  • Determination of moisture resistance of covered electrodes according to PN-EN ISO 14372
    • Katarzyna Mielnicka
    • Adrian Wolski
    • Aleksandra Świerczyńska
    • Grzegorz Rogalski
    • Dariusz Fydrych
    2019 Pełny tekst Przegląd Spawalnictwa

    Moisture present in the electrode covering is one of the sources of diffusible hydrogen in welded joints. In order to study the diffusible hydrogen content in deposited metal, a stand for moisturizing covered electrodes, in accordance with the PN-EN ISO 14372 standard, was built. After the stand was completed, a test of moisturizing the electrodes was carried out and measurements of the diffusible hydrogen content in deposited metal using the mercury method (according to PN-EN ISO 3690) were conducted. The research was aimed at verifying the correctness of the operation of test stand and indirect determination of the influence of storage of rutile-cellulose and cellulose electrodes under fixed conditions on the degree of moisturizing of the weld metal. Both tested electrode grades belong to the group of electrodes with a standard covering.

  • Determination of Odor Intensity of Binary Gas Mixtures Using Perceptual Models and an Electronic Nose Combined with Fuzzy Logic
    • Bartosz Szulczyński
    • Jacek Gębicki
    2019 Pełny tekst SENSORS

    Measurement and monitoring of air quality in terms of odor nuisance is an important problem. From a practical point of view, it would be most valuable to directly link the odor intensity with the results of analytical air monitoring. Such a solution is offered by electronic noses, which thanks to the possibility of holistic analysis of the gas sample, allow estimation of the odor intensity of the gas mixture. The biggest problem is the occurrence of odor interactions between the mixture components. For this reason, methods that can take into account the interaction between components of the mixture are used to analyze data from the e-nose. In the presented study, the fuzzy logic algorithm was proposed for determination of odor intensity of binary mixtures of eight odorants: n-Hexane, cyclohexane, toluene, o-xylene, trimethylamine, triethylamine, α-pinene, and β-pinene. The proposed algorithm was compared with four theoretical perceptual models: Euclidean additivity, vectorial additivity, U model, and UPL model.

  • Determination of Peak Impact Force for Buildings Exposed to Structural Pounding during Earthquakes
    • Seyed Mohammad Khatami
    • Hosein Naderpour
    • Carneiro Rui Barros
    • Anna Jakubczyk-Gałczyńska
    • Robert Jankowski
    2019 Pełny tekst Geosciences

    Structural pounding between adjacent, insufficiently separated buildings, or bridge segments, has been repeatedly observed during seismic excitations. Such earthquake-induced collisions may cause severe structural damage or even lead to the collapse of colliding structures. The aim of the present paper was to show the results of the study focused on determination of peak impact forces during collisions between buildings exposed to different seismic excitations. A set of different ground motion records, with various peak ground acceleration (PGA) values and frequency contents, were considered. First, pounding-involved numerical analysis was conducted for the basic parameters of colliding buildings. Then, the parametric study was carried out for different structural natural periods, structural damping ratios, gap sizes between buildings and coefficients of restitution. The results of the analysis conducted for the basic structural parameters indicate that the largest response of the analysed buildings was observed for the Duzce earthquake. The parametric study showed that the pounding-involved structural response depended substantially on all parameters considered in the analysis, and the largest response was observed for different ground motions. The results of the study presented in this paper indicate that the value of the peak impact force expected during the time of the earthquake does not depend on the PGA value of ground motion, but rather on the frequency contents of excitation and pounding scenario. It is therefore recommended that the peak impact force for buildings exposed to structural pounding during earthquakes should be determined individually for the specific structural configuration taking into account the design ground motion.

  • Determination of polycyclic aromatic hydrocarbons (PAHs) and other organic pollutants in freshwaters on the western shore of Admiralty Bay (King George Island, Maritime Antarctica).
    • Małgorzata Szopińska
    • Danuta Szumińska
    • Robert Józef Bialik
    • Tomasz Dymerski
    • Erwin Rosenberg
    • Żaneta Polkowska
    2019 Pełny tekst ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

    Organic contamination in freshwater samples has never been investigated at the western shore of Admiralty Bay. Therefore, the presence of polycyclic aromatic hydrocarbons (PAHs) in five different sites distributed along a shore running from the Arctowski Station to the Baranowski Glacier was studied. Moreover, organic compounds such as n-alkanes, toluene and ethylbenzene were also noted. Increased ΣPAHs in late Austral summer 2016 are the result of long-range atmospheric transport of air masses from South America, confirmed by 10-day backward air mass trajectories analysis. The presence of n-alkanes and other hydrocarbons, as well as the evaluation of PAH indices (e.g. ΣLMW/ΣHMW* > 1), shows the use of fuel and indicate local human activity. As a final conclusion, our analysis indicates a mixed origin of PAHs (global and local). The presence of PAHs and other hydrocarbons in the water environment may constitute a potentially negative effect on the Antarctic ecosystem and it should be investigated in detail during further research (//*ΣLMW—sum of low molecular weight PAHs (two- and three-ring PAHs); ΣHMW—sum of high molecular weight PAHs (four- and five-ring PAHs)//).

  • Determination of selected parameters/ analytes in surface water samples collected in the surroundings of the capital of Spitsbergen (Longyearbyen)
    • Ruman Marek
    • Michał Ciepły
    • Żaneta Polkowska
    2019 Pełny tekst AIP Conference Proceedings

    Polar regions are extremely sensitive to pollution such as harmful gases, particles or toxic substances which affect the Arctic climate and ecosystems. Spitsbergen, as well as all Arctic region, because of its geographically distant location and lack of industry sector, should be free of chemical pollution. Despite this, many pollutants could be found in the Polar environment, for example in freshwaters. Their occurrence is related with the global distillation process (Grasshopper effect) in which the contaminants from lower latitudes are transferred to the higher latitudes, resulting in the pollution of Arctic area. The purpose of the research was to determine the selected parameters: TOC (Total Organic Carbon) and formaldehyde, phenols in samples of freshwaterwater (surface water) collected in the area surrounding the capital of Spitsbergen (Longyearbyen). The aim was to investigate the pollution of Arctic freshwater. The obtained results of detected compounds may confirm the role of transport of contaminants over large distances in pollution of Polar regions.

  • Determination of the uncertainty of mass flow measurement using the orifice for different values of the Reynolds number
    • Anna Golijanek-Jędrzejczyk
    • Andrzej Mrowiec
    • Robert Hanus
    • Marcin Zych
    • Dariusz Świsulski
    2019 Pełny tekst

    Standard orifice flowmeters are widely used in the chemical and energy industry. Therefore, it is essential to know how accurate the measurements made with these instruments are. The paper presents an estimation of measurement uncertainty of a liquid mass flow using the orifice plate. The authors will present the influence of ranges of the Reynolds number on the estimated uncertainty, obtained on the basis of simulation and laboratory experiments. The research was conducted for the central orifice in the Reynolds number 8,000 < Re < 21,000. The results of estimating the extended uncertainty of the measurement of water flow using simulation and experimental method, are convergent. The maximum difference in the extended uncertainty values of flow measurement for the simulation and experiment was 0.04.10-3 kg/s.

  • Determination of Thermophysical Parameters Involved in The Numerical Model to Predict the Temperature Field of Cast-In-Place Concrete Bridge Deck
    • Aleksandra Kuryłowicz-Cudowska
    2019 Pełny tekst Materials

    The paper dealswith a concept of a practical computationmethod to simulate the temperature distribution in an extradosed bridge deck. The main goal of the study is to develop a feasible model of hardening of concrete consistent with in-situ measurement capabilities. The presented investigations include laboratory tests of high performance concrete, measurements of temperature evolution in the bridge deck and above all, numerical simulations of temperature field in a concrete box bridge girder. A thermal conductivity equation in the author’s program, using finite dierence method has been solved. New approach for identification of the model parameters and boundary conditions (heat transfer coecients) has been proposed. The numerical results are verified by means of a wide set of experimental tests carried out on three stages of the extradosed bridge studies. A high agreement between the concrete temperature distribution in the time and space domain was obtained. The temperature history of concrete hardening, supplemented with maturity method equations, made it possible to estimate an early-age compressive strength of the cast-in-place concrete. The proposed solution could be applied in a Structural Health Monitoring system for concrete objects.

  • Developing a Framework for the Implementation of Landscape and Greenspace Indicators in Sustainable Urban Planning. Waterfront Landscape Management: Case Studies in Gdańsk, Poznań and Bristol
    • Joanna Badach
    • Elżbieta Raszeja
    2019 Pełny tekst Sustainability

    Urban landscape (UL) management and urban greenspace (UG) delivery require effective planning tools. The aim of the study is to develop a conceptual framework for the implementation of ecological, structural and visual landscape and greenspace indicators (LGI) in spatial development of urban areas. The UL and UG management provisions in Poland are identified at various levels of urban planning (local, municipal and regional). Furthermore, the applicability of the selected set of LGI in the Polish planning system is considered based on the existing planning documents. The quality of UL and UG transformation is discussed in three case studies in Bristol, Gda ´nsk and Pozna ´n in the broader context of the English and Polish spatial planning systems. Bristol is used as a point of reference for the evaluation of UL and UG management in Poland and for the comparison between English and Polish landscape policies. Based on the conceptual framework and the analysis of the case studies, critical areas of UL and UG management in Poland are identified. The existing planning system often fails to ensure the continuity of landscape structures, and it does not include its preservation and enhancement to a sufficient extent. Therefore, the implementation of the proposed LGI framework could significantly improve the ecological and visual quality, as well as the structural diversity of UL and UG. Moreover, the article concludes by indicating some practical implications of the proposed LGI framework for urban planners, policy makers and other stakeholders in terms of improving the modes of governance for UL and UG management as well as of accounting for human health and well-being.

  • Developing Novel Solutions to Realise the European Energy - Information Sharing & Analysis Centre
    • Rafał Leszczyna
    • Tania Wallis
    • Michał Wróbel
    2019 Pełny tekst DECISION SUPPORT SYSTEMS

    For more effective decision making in preparation for and response to cyberevents in the energy sector, multilevel situation awareness, from technical to strategic is essential. With an uncertain picture of evolving threats, sharing of the latest cybersecurity knowledge among all sector stakeholders can inform and improve decisions and responses. This paper describes two novel solutions proposed during the formation of the European Energy -- Information Sharing \& Analysis Centre (EE-ISAC) to build situation awareness and support information sharing. The development of the EE-ISAC towards regular information sharing among members is described. This demonstrates the foundations achieved so far upon which a situation awareness network can be built for the energy sector.

  • Development and validation of a model that includes two ultrasound parameters and the plasma D-dimer level for predicting malignancy in adnexal masses: an observational study
    • Maciej Stukan
    • Michał Badocha
    • Karol Ratajczak
    2019 Pełny tekst BMC CANCER

    Background: Pre-operative discrimination of malignant from benign adnexal masses is crucial for planning additional imaging, preparation, surgery and postoperative care. This study aimed to define key ultrasound and clinical variables and develop a predictive model for calculating preoperative ovarian tumor malignancy risk in a gynecologic oncology referral center. We compared our model to a subjective ultrasound assessment (SUA) method and previously described models. Methods: This prospective, single-center observational study included consecutive patients. We collected systematic ultrasound and clinical data, including cancer antigen 125, D-dimer (DD) levels and platelet count. Histological examinations served as the reference standard. We performed univariate and multivariate regressions, and Bayesian information criterion (BIC) to assess the optimal model. Data were split into 2 subsets: training, for model development (190 observations) and testing, for model validation (n = 100). Results: Among 290 patients, 52% had malignant disease, including epithelial ovarian cancer (72.8%), metastatic disease (14.5%), borderline tumors (6.6%), and non-epithelial malignancies (4.6%). Significant variables were included into a multivariate analysis. The optimal model, included three independent factors: solid areas, the color score, and the DD level. Malignant and benign lesions had mean DD values of 2.837 and 0.354 μg/ml, respectively. We transformed established formulae into a web-based calculator (http://gin-onc-calculators.com/gynonc.php) for calculating the adnexal mass malignancy risk. The areas under the curve (AUCs) for models compared in the testing set were: our model (0.977), Simple Rules risk calculation (0.976), Assessment of Different NEoplasias in the adneXa (ADNEX) (0.972), Logistic Regression 2 (LR2) (0.969), Risk of Malignancy Index (RMI) 4 (0.932), SUA (0.930), and RMI3 (0.912). Conclusions: Two simple ultrasound predictors and the DD level (also included in a mathematical model), when used by gynecologist oncologist, discriminated malignant from benign ovarian lesions as well or better than other more complex models and the SUA method. These parameters (and the model) may be clinically useful for planning adequate management in the cancer center. The model needs substantial validation.

  • Development of beltless respiration and heartbeat sensor based on flexible piezoelectric film
    • Łukasz Sienkiewicz
    • Roland Ryndzionek
    • Mieczysław Ronkowski
    2019 Pełny tekst

    The main goal of this work is to report initial development on a respiration and heartbeat measurement sensor that can be used in continuous monitoring conditions at a minimal impact on the patient. General description of the sensor, consisting of a PVDF film and the bonding layer, is given. Open-circuit voltage generated by the sensor is estimated by analytical and numerical calculations. Analog and digital interface used to extract the bio-data is briefly described. Finally, signal conditioning with digital filters, as well as, measurements of respiration and heart rate at two locations are presented and discussed.

  • Development of Intelligent Road Signs with V2X Interface for Adaptive Traffic Controlling
    • Andrzej Czyżewski
    • Andrzej Sroczyński
    • Tomasz Śmiałkowski
    • Piotr Hoffmann
    2019 Pełny tekst

    The objective of this paper is to present a practical project of intelligent road signs, under which a series of new products for the regulation of traffic is being created. The engineering part of the project, described in this paper, was preceded by a series of experimental studies, the results of which were described in another paper accepted for publication at the MTS-ITS conference 2019, entitled "Comparative study on the effectiveness of various types road traffic detectors". A new kind of intelligent road signs which will enable the prevention of the most common collisions on highways, resulting from the rapid stacking of vehicles resulting most often from accidental heavy braking. A range of products is being developed, including intelligent road signs: standing, hanging and mobile ones, displaying dynamically updated driving the speed limit, determined automatically, through an embedded electronic module, enabling multimodal measurement of traffic conditions. Solving a number of research and construction problems, such as: effective and independent of weather conditions traffic monitoring based on simultaneous analysis of several types of data representation, development of a method of calculating gradients and histograms of vehicle speed for various types of road situations or traffic topologies. Moreover, creating a platform for self-organizing reliable wireless connections among road signs equipped with innovative displays and power supplies and carrying out prototype tests are carried out. As a result, advanced conceptually products for increasing road safety for which there is a market demand are being prepared for future implementation.

  • Diagnosing wind turbine condition employing a neural network to the analysis of vibroacoustic signals
    • Andrzej Czyżewski
    2019 Pełny tekst Journal of the Acoustical Society of America

    It is important from the economic point of view to detect damage early in the wind turbines before failures occur. For this purpose, a monitoring device was built that analyzes both acoustic signals acquired from the built-in non-contact acoustic intensity probe, as well as from the accelerometers, mounted on the internal devices in the nacelle. The signals collected in this way are used for long-term training of the autoencoder neural network. The appropriately trained network automatically detects deviations, signaling them to technical service. The applied methods of analysis of vibroacoustic signals and neural network training are the subject of the presented paper. In addition, the motion magnification of video is used for extracting information on vibrations of the whole wind turbine construction. Finally, spectral analysis is applied for detecting unnatural components presence meaning defects in both: visual and vibroacoustic representations. The process of reduction and construction of a wind turbine model is discussed with a particular emphasis on application to perform extensive tests of the developed methods and algorithms. [The research was subsidized by the Polish National Centre for Research and Development within the project “STEO—System for Technical and Economic Optimization of Distributed Renewable Energy Sources”, No. POIR.01.02.00-00-0357/16.]

  • DIAGNOSIS OF MALIGNANT MELANOMA BY NEURAL NETWORK ENSEMBLE-BASED SYSTEM UTILISING HAND-CRAFTED SKIN LESION FEATURES
    • Michał Grochowski
    • Agnieszka Mikołajczyk
    • Arkadiusz Kwasigroch
    2019 Pełny tekst Metrology and Measurement Systems

    Malignant melanomas are the most deadly type of skin cancer but detected early have high chances for successful treatment. In the last twenty years, the interest of automated melanoma recognition detection and classification dynamically increased partially because of public datasets appearing with dermatoscopic images of skin lesions. Automated computer-aided skin cancer detection in dermatoscopic images is a very challenging task due to uneven datasets sizes, the huge intra-class variation with small interclass variation, and the existence of many artifacts in the image. One of the most recognized methods of melanoma diagnosis is the ABCD method. In the paper, we propose an extended version of this method and an intelligent decision support system based on neural networks that uses its results in a form of hand-crafted features. Automatic determination of the skin features used by the ABCD method is difficult due to the large diversity of images of various quality, the existence of hair, different markers and other obstacles. Therefore, it was necessary to apply advanced methods of preprocessing the images. The system is an ensemble of ten neural networks, working in parallel and one network using their results to generate a final decision. This system structure allowed us to increase the efficiency of the operation by several percentage points compared to a single neural network. The proposed system is trained on over 5000 and tested afterward on 200 skin moles. The presented system can be used as a decision support system for primary care physicians, as a system capable of self-examination of the skin with a dermatoscope and also as an important tool to improve biopsy decision making.

  • Diagnostic Model of Crankshaft Seals
    • Piotr Bzura
    2019 Pełny tekst Polish Maritime Research

    T he paper presents a research stand being a diagnostic model of radial lip seals used, among others, on crankshafts of piston combustion engines in order to identify the correctness of their operation. The possibility of determining the technical condition of lip seals on the basis of the proposed coefficient of correctness of operation has been described. T he basic features of seals influencing their correctness of operation were also described, along with examples of determining the durability limits of lip seals. A modified version of the friction node of the T-02 four-ball apparatus is presented. It allows to check the correctness of sealing lips operation as well as to test the compatibility between the steel shaft, sealing lip and sealed lubricating oil. It was shown that the test results con-firmed the usefulness of the hypothesis that the quality of oil affects the durability of sealing lips and their coefficient of correctness. Additionally, attention was paid to the possibility of analyzing the pumping effect affecting the transition of the seal-shaft system from the state of partial suitability S2 to the state of full suitability S1 or to the state of unfitness S3, and because the change in the state of such a system is random, it requires a probabilistic analysis.

  • Diagnostics and monitoring of the longest span extradosed bridge in Europe
    • Mikołaj Miśkiewicz
    • Krzysztof Wilde
    2019

    The article presents complex diagnostic procedures applied for the purpose of behavior analysis of the extradosed bridge with the longest span in Europe that was built in 2018 in Poland. The system of health monitoring was used to: register internal forces in temporary supports, monitor concrete bonding, perform in situ diagnostics and operation tests. The bridge is a continuous four-span structure with spans theoretical lengths equaling: 132.5+206.0+206.0+132.5 m. During the construction of the bridge, two technical monitoring systems were used. As a consequence of their application, it was possible to carry out works with the lowest level of risk and therefore the work schedule was accelerated. The first of systems was designed to measure forces transferred to temporary supports during cantilever construction stages. The second system was designed to measure changes of the strength of curing concrete, after it was poured at the site, which allowed to speed up the removal of the scaffoldings and post-tension of cross section with cables. When the bridge was finished, a Structural Health Monitoring (SHM) system was installed and final acceptance tests were launched. The obtained results were used to validate theoretical assumptions done at the stage of the bridge structural design and provided insight into the complex bridge behavior.

  • Diagnostics of pillars in St. Mary’s Church (Gdańsk, Poland) using the GPR method
    • Jacek Lachowicz
    • Magdalena Rucka
    2019 Pełny tekst International Journal of Architectural Heritage

    The main goal of this study was non-destructive evaluation of pillars in the St. Mary’s Church (Gdańsk, Poland) using the ground penetrating radar (GPR) technique. The GPR inspection was conducted on four brick masonry pillars and five pillars strengthened by reinforced concrete jacketing. Data were acquired with a 2 GHz antenna along longitudinal and transverse profiles. The study involved the estimation of the electromagnetic wave velocity in both brick and concrete, the inspection of the internal structure of the pillars and the precise identification of reinforcement bars. To determine the wave velocity in bricks, a novel mathematical model was developed. Finite-difference time-domain (FDTD) simulations were used to verify and assess the feasibility of the proposed model. Finally, GPR maps were processed using the hyperbolic summation method to visualize the reinforcement distribution in the concrete jacket.

  • Diagonalized Macromodels in Finite Element Method for Fast Electromagnetic Analysis of Waveguide Components
    • Krzysztof Nyka
    2019 Pełny tekst Electronics

    A new technique of local model-order reduction (MOR) in 3-D finite element method (FEM) for frequency-domain electromagnetic analysis of waveguide components is proposed in this paper. It resolves the problem of increasing solution time of the reduced-order system assembled from macromodels created in the subdomains, into which an analyzed structure is partitioned. This problem becomes particularly relevant for growing size and count of the macromodels, and when they are cloned in multiple locations of the structures or are used repeatedly in a tuning and optimization process. To significantly reduce the solution time, the diagonalized macromodels are created by means of the simultaneous diagonalization and subsequently assembled in the global system. For the resulting partially diagonal matrix, an efficient dedicated solver based on the Schur complement technique is proposed. The employed MOR method preserves frequency independence of the macromodels, which is essential for efficient diagonalization, as it can be performed once for the whole analysis bandwidth. The numerical validation of the proposed procedures with respect to accuracy and speed was carried out for varying size and count of macromodels. An exemplary finite periodical waveguide structure was chosen to investigate the influence of macromodel cloning on the resultant efficiency. The results show that the use of the diagonalized macromodels provided a significant solution speedup without any loss of accuracy

  • Diaminophosphinoboranes: effective reagents for phosphinoboration of CO2
    • Natalia Szynkiewicz
    • Anna Ordyszewska
    • Jarosław Chojnacki
    • Rafał Grubba
    2019 Pełny tekst RSC Advances

    The monomeric diaminophosphinoboranes readily react with CO2 under mild conditions to cleanly form products of the general formula R2P-C(=O)-O-B(NR2)2 in the absence of a catalyst. The isolated products from the CO2-phosphinoboration were fully characterized by NMR spectroscopy, IR spectroscopy, and X-ray diffraction. The mechanism of CO2 phosphinoboration with diaminophosphinoboranes was elucidated by DFT calculations.

  • Die Sandgrube „Köplitz“ – ein interessanter geologischer Aufschluss am Nordwestrand der Schmiedeberger Stauchendmoräne
    • Roland Wimmer
    • Ewa Wagner-Wysiecka
    2019 Pełny tekst Mauritiana

    Die Kiessandgrube Köplitz ermöglicht einen Einblick in die komplizierten, durch glazidynamische Überprägung gekennzeichneten geologischen Lagerungsverhältnisse im Bereich der Schmiedeberger Stauchendmoräne. Anhand neuer Geländedokumentationen wird ein kleiner Eindruck vom komplizierten injektiven „Fließfalten-Schuppenbau“ der Stauchendmoräne vermittelt. Die steil aufgerichteten, aus tertiären (Untermiozän bis Oligozän) und quartären (elster- bis saalekaltzeitlichen) Sedimenten bestehenden Schollenpakete streichen nahezu an der Geländeoberfläche aus. In den tertiären Ablagerungen wurden in den letzten Jahren wiederholt Einzelfunde von Bernstein gemacht. Sie wurden mittels der Infrarotspektroskopie untersucht.

  • Dietary antioxidants as a source of hydrogen peroxide
    • Michalina Grzesik
    • Grzegorz Bartosz
    • Ireneusz Stefaniuk
    • Monika Pichla
    • Jacek Namieśnik
    • Izabela Sadowska-Bartosz
    2019 FOOD CHEMISTRY

    Studies of 54 antioxidants revealed that 27 of them, mainly polyphenols, generated hydrogen peroxide (H2O2) when added to Dulbecco’s modified Eagle’s medium (DMEM), other media used for culture of mammalian and yeast cells and phosphate-buffered saline. The most active antioxidants were: propyl gallate (PG), (−)-epigallocatechin gallate (EGCG) and quercetin (Q). Chelex treatment and iron chelators decreased H2O2 generation suggesting that transition metal ions catalyze antioxidant autoxidation and H2O2 production. Green tea also generated H2O2; tea prepared on tap water generated significantly more H2O2 than tea prepared on deionized water. Ascorbic acid decreased H2O2 production although it generated H2O2 itself, in the absence of other additives. Lemon added to the tea significantly reduced generation of H2O2. Hydrogen peroxide generated in the medium contributed to the cytotoxicity of PG, EGCG and Q to human prostate carcinoma DU-145 cells, since catalase increased the survival of the cells subjected to these compounds in vitro.

  • Diethyl carbonate as a green extraction solvent for chlorophenol determination with dispersive liquid–liquid microextraction
    • Marek Tobiszewski
    • Weronika Zabrocka
    • Marta Bystrzanowska
    2019 Pełny tekst Analytical Methods

    The principles of green analytical chemistry indicate that the search for greener organic solvents for extraction applications is crucial. In this study diethyl carbonate (DEC) is proved to be a green solvent, as it is relatively nontoxic, obtainable from renewable resources and biodegradable. Here it is applied as an extraction solvent for chlorophenol determination in water samples with dispersive liquid–liquid microextraction. The multiobjective optimization for 7 chlorophenols is done with the design of an experiment combined with Derringer's desirability function. The optimized parameters in the extraction step are 300 mL of DEC, 0.5 mL of methanol, 8 mL of water sample and 7.5% of inorganic salt addition. The values of LOQ are from 0.01 to 0.3 mg L1, and CVs are between 7.1 and 17.3% for 7 CPs. In this study DEC is proved to be a promising, green solvent, applicable in analytical extractions.

  • Differences between selected volatile aromatic compound concentrations in sludge samples in various steps of wastewater treatment plant operations
    • Hubert Byliński
    • Justyna Aszyk
    • Paweł Kubica
    • Małgorzata Szopińska
    • Sylwia Fudala-Książek
    • Jacek Namieśnik
    2019 JOURNAL OF ENVIRONMENTAL MANAGEMENT

    Sewage sludge, one of the main wastes generated during wastewater treatment, constitutes an important source of emissions of volatile chemical compounds such as volatile aromatic compounds These substances may undergo various changes as a result of operations and unit processes, which affects their concentrations in sewage sludge. An important factor determining the potential hazardousness of volatile organic compounds is the quality of wastewater delivered to wastewater treatment plants and the technical and equipment solutions applied to wastewater. In this study, a rapid and sensitive headspace gas chromatography method, coupled with tandem mass spectrometry using the standard addition method, was developed for the determination of selected volatile aromatic compounds in sewage sludge samples collected at different stages from three wastewater treatment plants located in Poland. This study attempted to assess the relationship between differences in the emissions of representative VACs and the given stage of the technological process within three analysed wastewater treatment plants. The highest concentration levels were determined for p-cresol, with concentrations ranging from 44.0*101±5.6*101 ng/g of sludge (sludge from aerobic chamber, wastewater treatment plant no.2) to 47.7*102±6.9*102 ng/g of sludge (sludge from aerobic chamber, wastewater treatment plant no.1), while the lowest concentration levels were observed for chlorobenzene, with concentrations ranging from 0.1300 ± 0.0030 ng/g of sludge (sludge from anaerobic chamber, wastewater treatment plant no.2), to 0.2606 ± 0.0046 ng/g of sludge (primary sludge, wastewater treatment plant no.1). The repeatability of the method was better than 10%, with accuracy levels in the ranges 89%–108%.Wastewater treatment technologies and residual sludge management in the selected wastewater treatment plantsinfluenced volatile aromatic compounds emission. Furthermore, the diversity of the wastewater quality, depending on the catchment area, is also an important factor determining the differentiation in volatile aromatic compounds emission. The microbial composition of raw wastewater highly influenced not only the treatment effectiveness of wastewater treatment plants but also the production of intermediate products, such as volatile aromatic compounds, which may contribute to odour emissions.

  • Digital Government as Implementation Means for Sustainable Development Goals
    • Ignacio Marcovecchio
    • Mamello Thinyane
    • Elsa Estevez
    • Tomasz Janowski
    2019 Pełny tekst International Journal of Public Administration in the Digital Age

    One of the challenges for implementing Sustainable Development Goals (SDGs) is the measurement of indicators that represent progress towards such goals. Measuring such progress enables data-driven decision-making and management of SDG-relevant projects and strategies. The premise of this research is that measuring such indicators depends on measuring so-called means of implementation, i.e. activities that directly contribute to the achievement of SDGs. Building on this premise, this article studies how the measurement of digital government (DG) can contribute to the measurement of SDGs. In particular, how the indicators originating in three DG measurement instruments can inform the SDG indicators. The main finding is an alignment matrix, showing how the DG indicators contribute with varying level of specificity to the measurement of 10 SDG indicators.

  • Dimethyl ether (DME) as potential environmental friendly fuel
    • Patrycja Makoś
    • Edyta Słupek
    • Joanna Sobczak
    • Dawid Zabrocki
    • Jan Hupka
    • Andrzej Rogala
    2019 Pełny tekst E3S Web of Conferences

    In recent years, there has been a growing interest in replacing petroleum fuels with so-called second generation environmental friendly fuels. Compared to traditional petroleum fuels dimethyl ether (DME) could be used as a clean high-efficiency compression ignition fuel with reduced particulate matter (PM), sulfur oxides (SOx), hydrocarbons (HC), carbon monoxide (CO) as well as combustion noise. Compared to some of the other leading alternative fuel candidates i.e., methane, methanol, ethanol, compressed natural gas, DME appears to have the largest potential impact on society including well-to-wheel greenhouse gas emissions, non-petroleum feedstocks, well-to-wheel efficiencies, fuel versatility, infrastructure, availability, economics, and safety and should be considered as the fuel of choice for eliminating the dependency on petroleum. This paper reviews the properties and the DME combustion effects on environmental and they were compared to diesel characteristic as well as the effect of blending DME with liquefied petroleum gas (LPG), conventional diesel fuel and biodiesel were discussed.

  • Diphosphination of CO2 and CS2 mediated by frustrated Lewis pairs - catalytic route to phosphanyl derivatives of formic and dithioformic acid
    • Natalia Szynkiewicz
    • Łukasz Ponikiewski
    • Rafał Grubba
    2019 Pełny tekst CHEMICAL COMMUNICATIONS

    The first example of CO2 diphosphination is described. Reactions of unsymmetrical diphosphanes with CE2 (E = O, S) catalyzed by BPh3 insert a CE2 molecule into the P-P bond with formation of the products of the general formula R2P-E-C(=E)-PR2. The obtained CO2 adducts arise from synergistic interaction of diphosphane and borane with CO2 molecule.

  • Dirac fermions and possible weak antilocalization in LaCuSb2
    • Juan Chamorro
    • A. Topp
    • Y. Fang
    • Michał Winiarski
    • C. R. Ast
    • M. Krivenkov
    • A. Varykhalov
    • B. J. Ramshaw
    • Leslie Schoop
    • Tyrel McQueen
    2019 Pełny tekst APL Materials

    Layered heavy-metal square-lattice compounds have recently emerged as potential Dirac fermion materials due to bonding within those sublattices. We report quantum transport and spectroscopic data on the layered Sb square-lattice material LaCuSb2. Linearly dispersing band crossings, necessary to generate Dirac fermions, are experimentally observed in the electronic band structure observed using angle-resolved photoemission spectroscopy, along with a quasi-two-dimensional Fermi surface. Weak antilocalization that arises from two-dimensional transport is observed in the magnetoresistance, as well as regions of linear dependence, both of which are indicative of topologically nontrivial effects. Measurements of the Shubnikov–de Haas quantum oscillations show low effective mass electrons on the order of 0.065me, further confirming the presence of Dirac fermions in this material.

  • Discovering Rule-Based Learning Systems for the Purpose of Music Analysis
    • Grazina Korvel
    • Bożena Kostek
    2019 Pełny tekst Journal of the Acoustical Society of America

    Music analysis and processing aims at understanding information retrieved from music (Music Information Retrieval). For the purpose of music data mining, machine learning (ML) methods or statistical approach are employed. Their primary task is recognition of musical instrument sounds, music genre or emotion contained in music, identification of audio, assessment of audio content, etc. In terms of computational approach, music databases contain imprecise, vague and indiscernible data objects. Moreover, most of the machine learning algorithms outcomes are given as a black-box result. Also, underfitting or overfitting may occur, meaning that either the model description is not complex enough or the test set is too small or not sufficiently representative. Thus the goal is to generalize the model. To overcome some of these problems, rule-based systems may be used, e.g., based on rough set theory that shows the outcome in the form of rules interconnecting features retrieved from music. Thus, first, principles of rule-based classifiers and particularly rough sets (RS) are presented, showing their usability in the music domain. A potential of the rough set-based approach was shown in the context of music genre recognition. The results were analyzed in terms of the recognition rate and computation time efficiency.

  • Discovery of Stylistic Patterns in Business Process Textual Descriptions: IT Ticket Case
    • Nina Rizun
    • Aleksandra Revina
    • Vera Maister
    2019 Pełny tekst

    Growing IT complexity and related problems, which are reflected in IT tickets,create a need for new qualitative approaches. The goal isto automate the extraction of main topics described in tickets in order to provide high quality support for the IT process workers and enablea smooth service delivery to the end user. Present paper proposes a method of knowledge extraction in a form of stylistic patterns in business process (BP) texts, here in incoming IT tickets texts. Hereby, the authors set an objective to predicttheir readability andperceivedcomplexityfor a process worker, what will influencefurther tasks execution. The results of experimental analysis of a data set of incoming ticket texts from anITIL-based Change Management process showed that the specificity of stylistic patterns expressing the readability of a ticket and perceived complexity could be identified with the help of proposed measures of the ticket length, parts-of-speech distributions and wording style (PDF) Discovery of Stylistic Patterns in Business Process Textual Descriptions: IT Ticket Case. Available from: https://www.researchgate.net/publication/331843977_Discovery_of_Stylistic_Patterns_in_Business_Process_Textual_Descriptions_IT_Ticket_Case [accessed Jun 23 2019].

  • Discussion on “Coupled effective stress analysis of insertion problems in geotechnics with the Particle Finite Element Method” by L. Monforte, M. Arroyo, J.M. Carbonell, and A. Gens
    • Jakub Konkol
    • Lech Bałachowski
    2019 Pełny tekst COMPUTERS AND GEOTECHNICS

    Addressed here is the Particle Finite Element Method (PFEM) modelling of undrained CPTu penetration with regard to a reference analytical solution based on the Spherical Cavity Expansion Method (SCEM). Also discussed is the choice of the soil model and its parameters. The effect of cone interface friction on CPTu simulation is analyzed in a series of penetration tests using Arbitrary Lagrangian-Eulerian (ALE) and Updated Lagrangian (UL) methods. The results of the simulations are compared with the Authors’ proposal.

  • Dispersive liquid-liquid microextraction combined with gas chromatography–mass spectrometry for in situ determination of biogenic amines in meat: Estimation of meat's freshness
    • Wojciech Wojnowski
    • Justyna Płotka-Wasylka
    • Jacek Namieśnik
    2019 Pełny tekst MICROCHEMICAL JOURNAL

    A dispersive liquid-liquid microextraction (DLLME) gas chromatography–mass spectrometry (GC–MS) technique was developed for the determination of selected biogenic amines (BAs) in samples of poultry, pork and beef. Prior to the extraction process, an appropriate volume of sodium hydroxide solution was added to each of the portioned samples. Next, samples were homogenized, centrifuged and finally sonicated at an increased temperature. After another centrifugation, the supernatant was made up to 50 mL in a calibrated flask. Subsequently, 5 mL of supernatant was separately subjected to a derivatization and extraction procedure. A mixture of methanol (dispersive solvent; 210 μL), chloroform (extractive solvent; 300 μL), and isobutyl chloroformate (derivatizing reagent; 100 μL) was used in the extraction process together with an admixture of pyridine and HCl in order to eliminate the by-products. The application of the method enables fast derivatization and extraction of the BAs and a straightforward and rapid sample enrichment. It displayed good linearity, intra- and inter-day precision and good recoveries. The proposed methodology is characterized by low limits of detection and quantification (0.003–0.009 μg/g and 0.009–0.029 μg/g, respectively). The green character of the method was established based on the results of two tools, namely the Analytical Eco-Scale and GAPI. It was successfully used to analyse samples of poultry, porcine and bovine meat. Multivariate statistical data analysis was applied in order to evaluate the potential use of the determined BAs as spoilage markers of particular meat types.

  • Dissociative ionization dynamics of dielectric gas C3F7CN
    • Milos Ranković
    • J Chalabala
    • Mateusz Zawadzki
    • Jaroslav Kočišek
    • Petr Slavíček
    • Juraj Fedor
    2019 PHYSICAL CHEMISTRY CHEMICAL PHYSICS

    Fluoronitrile C3F7CN is a promising candidate for the replacement of SF6 dielectric gas in high-voltage insulation. We present a combined experimental and theoretical study on its ionization dynamics probed in the 0-100 eV energy range. We exploited the total ion collection technique to determine the absolute ionization cross section, mass spectrometry to determine the fragment branching ratios and ab initio nonadiabatic molecular dynamics to simulate the ionization process. The latter two approaches showed the dominating presence of the CF+3 cation over the whole electron energy range. The Binary-Encounter-Bethe (BEB) approximation reproduces experimental cross sections very well and reveals that the ionization from a surprisingly large number of orbitals contributes almost equally to the processes. We show that the initially populated cation excited states undergo an ultrafast internal conversion to the ground state where the dissociation into a single decay channel takes place. Implications for the use of C3F7CN as an insulating material are discussed.

  • Distortional buckling of composite thin-walled columns of a box-type cross section with diaphragms
    • Czesław Szymczak
    • Marcin Kujawa
    2019 Pełny tekst ACTA MECHANICA

    Distortional buckling of axially compressed columns of box-like composite cross sections with andwithout internal diaphragms is investigated in the framework of one-dimensional theory. The channel membersare composed of unidirectional fibre-reinforced laminate. Two approaches to the member orthotropic materialare applied: homogenization based on the theory of mixture and periodicity cells, and homogenization basedon the Voigt–Reuss hypothesis. The principle of stationary total potential energy is applied to derive thegoverning differential equation. The obtained buckling stress is valid in the linear elastic range of columnmaterial behaviour. Numerical examples address simply supported columns, and analytical critical stressformulas are derived. The analytical and FEM solutions are compared, and sufficient accuracy of the resultsis observed.

  • Distributed Architectures for Intensive Urban Computing: A Case Study on Smart Lighting for Sustainable Cities
    • Higinio Mora
    • Jesus Peral
    • Antonio Ferrandez
    • David Gil
    • Julian Szymański
    2019 Pełny tekst IEEE Access

    New information and communication technologies have contributed to the development of the smart city concept. On a physical level, this paradigm is characterised by deploying a substantial number of different devices that can sense their surroundings and generate a large amount of data. The most typical case is image and video acquisition sensors. Recently, these types of sensors are found in abundance in urban spaces and are responsible for producing a large volume of multimedia data. The advanced computer vision methods for this type of multimedia information means that many aspects can be dynamically monitored, which can help implement value-added applications in the city. However, obtaining more elaborate semantic information from these data poses significant challenges related to a large amount of data generated and the processing capabilities required. This work aims to address these issues by using a combination of cloud computing technologies and mobile computing techniques to design a three-layer distributed architecture for intensive urban computing. The approach consists of distributing the processing tasks among a city’s multimedia acquisition devices, a middle computing layer, known as a cloudlet, and a cloud-computing infrastructure. As a result, each part of the architecture can now focus on a small number of tasks for which they are especially designed, and data transmission communication needs are significantly reduced. To this end, the cloud server can hold and centralise the multimedia analysis of processed results from the lower layers. Finally, a case study on smart lighting is described to illustrate the benefits of using the proposed model in smart city environments.

  • DISTRIBUTION OF FLOWS IN A CHANNEL NETWORK UNDER STEADY FLOW CONDITIONS
    • Dariusz Gąsiorowski
    • Wojciech Artichowicz
    2019 Pełny tekst Acta Scientiarum Polonorum Formatio Circumiectus

    The article presents an algorithm for calculating the distribution of flow in a junction of open channel network under steady flow conditions. The article presents a simplified calculation algorithm used to estimate the distribution of flow in a network of channels under steady flow conditions. The presented algorithm is based on the continuity equation and a simplified energy equation. To describe the relationship between the depth of water and the flow rate, the Manning’s equation was used to express discharge in the main channel, whereas in case of other channels, with hydraulic structures, appropriate equations describing the flow over a weir and through the culverts were used. Substitution of the abovementioned relationships with the continuity equation leads to a non-linear algebraic equation with respect to the water level. The resulting equation can be solved with iterative numerical methods. Calculation example using the proposed algorithm was carried out for the hydraulic system located on the Strzyża stream in Gdańsk. The presented approach can be an alternative to analytical-graphic method and it does not require formulation of the boundary problem for the

  • Distribution Transformer with Multi-Zone Voltage Regulation for Smart Grid System Application
    • Ryszard Strzelecki
    • Wojciech Matelski
    • Robert Małkowski
    • Valentin Tomasov
    • Leszek Wolski
    • Antoni Krahel
    2019 Pełny tekst

    The article presents four concepts of the multi-zone voltage regulation (MZVR) system. It is a combination of a distribution transformer with an on-load tap-changer, for step voltage regulation, and a power electronic converter, dimensioned for a fraction of MZVR power, realizing continuous voltage regulation, supplemented by a special switch, the so-called bypass. This allows voltage regulation at high resolution, wide range and with high dynamics and increased reliability. The work contains selected computer simulation results of the continuous regulation system, and considerations about extending the MZVR continuous voltage regulation range and its power level.

  • DME as alternative fuel for compression ignition engines – a review
    • Denys Stepanenko
    • Zbigniew Kneba
    2019 Pełny tekst Combustion Engines

    The ecological issues and the depletion of crude oil, has led the researchers to seeking for non-petroleum based alternative fuels, along with more advanced combustion technologies, and after-treatment systems. The use of clean alternative fuels is the one of the most perspective method that aiming at resolving of the said issues. One of the promising alternative fuels that can be used as a clean highefficiency compression ignition fuel with reduced of toxic emissions is dimethyl ether (DME). Moreover, it can be produced from various feedstocks such as natural gas, coal, biomass and others. This article describes the properties and the potential of DME application on the combustion and emission reduction characteristics of the compression ignition engines.

  • DMSO hydration redefined: Unraveling the hydrophobic hydration of solutes with a mixed hydrophilic–hydrophobic characteristic
    • Aneta Panuszko
    • Piotr Bruździak
    • Maciej Śmiechowski
    • Marcin Stasiulewicz
    • Joanna Stefaniak
    • Janusz Stangret
    2019 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    Hydrophobic hydration of solutes with a mixed hydrophilic--hydrophobic characteristics is still poorly understood. This is because both experimental and theoretical methods find it difficult to see the ice-like water structure around the nonpolar solute groups, unlike hydrogen bonds with the hydrophilic groups. In order to unravel this problem, we have investigated DMSO hydration by means of infrared spectroscopy and theoretical methods, namely DFT, ONIOM calculations and AIMD simulations, which allowed us to redefine its hydration. In dilute DMSO solutions the clathrate-like water is formed around the DMSO molecule, supported by interactions of water molecules with the methyl hydrogens (the blue-shifted hydrogen bonds). The cage is constructed by water molecules that form hydrogen bonds of the comparable energy and length with the SO group and between water molecules. When the construction of the cage is completed, DMSO molecule partially regains its rotational freedom inside. Strong hydrogen bonds within the frame are masked by the relatively small population of weakened hydrogen bonds of water molecules in the vicinity of the SO group, due to the improper fit to the bulk water of water molecules hydrogen bonded to the oxygen atom of DMSO. We also propose a new explanation of the highly non-ideal mixing behavior of aqueous DMSO solutions at the eutectic point, as the positive excess entropy of the equimolar amounts of molecular complexes distinguished in the system.

  • DNA Methylation Changes Induced by Redox-Active Compounds—Choosing the Right PCR-Based Method
    • Patrycja Jakubek
    • Jovana Rajić
    • Monika Baranowska
    • Melita Vidaković
    • Agnieszka Bartoszek-Pączkowska
    • Jacek Namieśnik
    2019 Pełny tekst Proceedings

    The impact of catechins on the expression profile of redox-related genes in HT29 cell line has been studied recently by our group using Oxidative Stress RT2 Profiler PCR Array. Within the examined panel of 84 genes, the down-regulation of SRXN1 gene was unique among other up-regulated genes. We hypothesized that the observed down-regulation resulted from DNA methylation and have exploited this observation to choose the proper strategy to monitor the changes in DNA methylation patterns incurred by dietary antioxidants. The current study verified two PCR-based approaches.

  • Do online reviews reveal mobile application usability and user experience? The case of WhatsApp
    • Anna Baj-Rogowska
    • Paweł Weichbroth
    2019 Pełny tekst Annals of Computer Science and Information Systems

    The variety of hardware devices and the diversity of their users imposes new requirements and expectations on designers and developers of mobile applications (apps). While the Internet has enabled new forms of communication platform, online stores provide the ability to review apps. These informal online app reviews have become a viral form of electronic wordof-mouth (eWOM), covering a plethora of issues. In our study, we set ourselves the goal of investigating whether online reviews reveal usability and user experience (UUX) issues, being important quality-in-use characteristics. To address this problem, we used sentiment analysis techniques, with the aim of extracting relevant keywords from eWOM WhatsApp data. Based on the extracted keywords, we next identified the original users’ reviews, and individually assigned each attribute and dimension to them. Eventually, the reported issues were thematically synthesized into 7 attributes and 8 dimensions. If one asks whether online reviews reveal genuine UUX issues, in this case, the answer is definitely affirmative.

  • Doktorant PG – Jutronauta w NASA
    • Adam Dąbrowski
    2019 Pełny tekst Pismo PG

    Mgr inż. Adam Dąbrowski, doktorant i asystent na Wydziale Mechanicznym, został laureatem konkursu Gazety Wyborczej „Jutronauci. Bilet za horyzont”, w ramach którego odbył staż w Jet Propulsion Laboratory (JPL), laboratorium NASA w Pasadenie w Kalifornii.

  • Dokumentacja oraz wnioski z badań prototypowego stropu typu filigran z wkładką styropianową dla firmy Strobud Prefabrykacja sp. z o.o.
    • Krystyna Nagrodzka-Godycka
    • Marek Wesołowski
    • Jarosław Kondrat
    • Maciej Solarczyk
    2019

    Niniejsze opracowanie stanowi dokumentację oraz wnioski z badań prototypowego stropu typu filigran z wkładką styropianową.

  • Domination subdivision and domination multisubdivision numbers of graphs
    • Magda Dettlaff
    • Joanna Raczek
    • Jerzy Topp
    2019 Pełny tekst Discussiones Mathematicae Graph Theory

    The domination subdivision number sd(G) of a graph G is the minimum number of edges that must be subdivided (where an edge can be subdivided at most once) in order to increase the domination number of G. It has been shown [10] that sd(T)<=3 for any tree T. We prove that the decision problem of the domination subdivision number is NP-complete even for bipartite graphs. For this reason we define the domination multisubdivision number of a nonempty graph G as a minimum positive integer k such that there exists an edge which must be subdivided k times to increase the domination number of G. We show that msd(G)<=3 for any graph G. The domination subdivision number and the domination multisubdivision number of a graph are incomparable in general, but we show that for trees these two parameters are equal. We also determine the domination multisubdivision number for some classes of graphs.

  • Doped Nanocrystalline Diamond Films as Reflective Layers for Fiber-Optic Sensors of Refractive Index of Liquids
    • Monika Kosowska
    • Daria Majchrowicz
    • Kamatchi J Sankaran
    • Mateusz Ficek
    • Ken Haenen
    • Małgorzata Szczerska
    2019 Pełny tekst Materials

    This paper reports the application of doped nanocrystalline diamond (NCD) films—nitrogen-doped NCD and boron-doped NCD—as reflective surfaces in an interferometric sensor of refractive index dedicated to the measurements of liquids. The sensor is constructed as a Fabry–Pérot interferometer, working in the reflective mode. The diamond films were deposited on silicon substrates by a microwave plasma enhanced chemical vapor deposition system. The measurements of refractive indices of liquids were carried out in the range of 1.3 to 1.6. The results of initial investigations show that doped NCD films can be successfully used in fiber-optic sensors of refractive index providing linear work characteristics. Their application can prolong the lifespan of the measurement head and open the way to measure biomedical samples and aggressive chemicals.

  • Doraźna nośność słupów o przekroju kołowym z rur FRP wypełnionych betonem Badania, teoria, obliczanie
    • Marcin Abramski
    2019

    Praca ma charakter monografii opisującej aktualny stan wiedzy z zakresu badań, teorii i projektowania słupów CFFT (concrete-filled fiber-reinforced polymer tube). Celem prowadzonych przez autora prac studialnych i badań własnych, w tym eksperymentalnych, jest szczegółowa analiza doraźnej nośności i zachowania się słupów CFFT poddanych ściskaniu osiowemu i mimośrodowemu. W pierwszym rozdziale wyjaśniono motywację autora do podjęcia tej tematyki, przedstawiając ją jednocześnie jako niszę badawczą. W rozdziale drugim opisano na konkretnych przykładach najbardziej odpowiednie dla słupów CFFT obszary zastosowań: jako obiekty infrastruktury morskiej i mostowej. Rozdziały trzeci i czwarty mają na celu przedstawienie aktualnego stanu wiedzy, odpowiednio na temat zachowania betonu skrępowanego w słupach z rur stalowych lub kompozytowych wypełnianych betonem (concrete filled tube) oraz uwzględniania efektów drugiego rzędu w obliczaniu nośności słupów z betonu. W rozdziale trzecim przywołano wyselekcjonowane, zdaniem autora – mające charakter najbardziej poznawczy badania obce i opatrzono je komentarzem. W rozdziale czwartym natomiast wzięto pod uwagę normatywy projektowania słupów z betonu: przede wszystkim europejskie (Eurokody), ale także amerykańskie, międzynarodowe i wybrane krajowe. W rozdziale piątym, najbardziej obszernym, przedstawiono badania eksperymentalne, w przeważającej części własne, poświęcone nośności i zachowaniu słupów CFFT ściskanych osiowo lub mimośrodowo. W całości własne w tym rozdziale są obszerne badania eksperymentalne własności kompozytów FRP rur, których użyto do wykonania wspomnianych słupów. Dla trzech zastosowanych kompozytów wyznaczono podstawowe stałe materiałowe, wymagane w teorii liniowej sprężystości. Ponieważ były to badania nietypowe dla inżynierii budowlanej, zastosowano procedury nie tylko normowe, lecz także własne, zaproponowane przez autora. Wszystkie przeprowadzone badania opisane w pracy pozwoliły na sformułowanie propozycji metody wyznaczania doraźnej nośności słupów CFFT. Przedstawiono ją w rozdziale szóstym. Opracowując metodę, wzorowano się przede wszystkim na Eurokodach oraz na amerykańskim normatywie poświęconym projektowaniu słupów CFFT. Dla zaproponowanej metody opracowano program komputerowy i przy jego użyciu sprawdzono zgodność wyników nośności obliczonych metodą autorską z wynikami eksperymentów. Na zakończenie nakreślono kierunki dalszych badań nad słupami CFFT.

  • Drewniane więźby dachowe żuławskich domów podcieniowych typu III – badania, stan zachowania, analiza
    • Tomasz Zybała
    2019 Pełny tekst Budownictwo i Architektura

    Zabytkowe domy podcieniowe ujścia Delty Wisły były obiektem zainteresowań wielu badaczy, jednak ich prace koncentrowały się głównie na aspektach historyczno-architektonicznych. Nie ma publikacji skupiających się na szczegółach i dokładnych analizach ustrojów budowlanych dla tej grupy historycznych obiektów. Artykuł jest rezultatem badań terenowych, kwerendy archiwalnej i obliczeń wykonanych przez autora. W pracyprzeanalizowano konstrukcje więźb dachowych zachowanych domów podcieniowych typu III.Autor wykonał zestawienia elementów nośnych dachów, połączeń ciesielskich, kątów nachylenia krokwi, opisał także stan zachowania wiązarów dachowych.Praca zawiera również obliczenia średniej objętości materiału konstrukcyjnego wiązara więźby dachowej przypadającego na metr kwadratowy rzutu połaci dachowej.

  • DREWNO i DOM. Drewno w architekturze mieszkalnej dawnego Wejherowa
    • Anita Jaśkiewicz-Sojak
    • Kurpiewski Maciej
    2019

    Drewno jest jednym z podstawowych materiałów budowlanych, który bardzo często był wykorzystywany w budownictwie minionych okresów historycznych. Drewno stosowano zarówno jako materiał konstrukcji budynków lub ich części, jak i tworzywo do kształtowania poszczególnych elementów i detalu architektonicznego. Wystawa przedstawia różne sposoby wykorzystania tego materiału budowlanego w architekturze mieszkaniowej Wejherowa w przeszłości. Rozważania na ten temat zostały zilustrowane archiwalnymi fotografiami i kartami pocztowymi dawnego Wejherowa, powstałymi w końcu XIX i w pierwszej połowie XX wieku. Ilustracjom towarzyszą także eksponaty, drewniane elementy zabytkowych budynków, które udało się zabezpieczyć i zachować. Są one dowodami na kruchość i nietrwałość drewna oraz świadczą o tym, że materialne dziedzictwo drewniane powoli znika z miejskiego krajobrazu i - paradoksalnie - powoli przekształca się w dziedzictwo niematerialne.

  • Droga S7 Koszwały – Kazimierzowo – geotechniczne aspekty inwestycji.
    • Grzegorz Horodecki
    2019 Magazyn Autostrady

    W artykule przedstawiono ogólne informacje dotyczące geotechnicznych aspektów projektu i realizacji drogi S7 na odcinku Koszwały – Kazimierzowo, ze szczególnym uwzględnieniem rozwiązań z zastosowaniem technologii zamkniętego materaca odciążającego z kruszywa lekkiego – keramzytu geotechnicznego. Przedstawiono metody wzmocnienia podłoża przyjęte na etapie projektu oraz realizacji wraz z monitoringiem geotechnicznym.

  • Drop-coating deposition surface-enhanced Raman spectroscopy on silver substrates for biofluid analysis
    • Maciej Wróbel
    • Zufang Huang
    • Soumik Siddhanta
    • Ishan Barman
    2019 Pełny tekst

    Utilization of surface-enhanced Raman spectroscopy as a measurement technique is of particular interest in biodetection due to its superb chemical specificity and high sensitivity. The use of SERS substrates further improve this method by massive enhancement of the molecule Raman spectrum, permitting very low levels of detection. Therefore it is important to seek for new ways to develop reliable substrates, which are quickly and easily manufactured at a low cost. This paper describes the development of a simple and cost-effective substrate for the SERS detection. The substrate is synthesized from a silver ink on the glass, and its utilization for biodetection is shown. The hydrophobicity of the substrate permits the pre-concentration benefit of the drop-coating deposition, by the formation of the coffee-ring. This allows to achieve lower limits of detection, by effectively measuring areas with higher concentration of measured molecules than the initial sample. However, the different properties of the medium, such as the influence of protein types and amounts, may influence the ring formation mechanics, thus effectively changing the pre-concentration of the target analyte.