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Gdańsk University of Technology

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  • Green analytical chemistry: Social dimension and teaching
    • Aleksandra Kurowska-Susdorf
    • Marcin Zwierżdżyński
    • Anita Bevanda
    • Stanislava Talić
    • Anita Ivanković
    • Justyna Płotka-Wasylka
    2019 Full text TRAC-TRENDS IN ANALYTICAL CHEMISTRY

    Green Analytical Chemistry (GAC) is the idea which every analytical chemist should be familiar of. Due to continuous improvement in the subject both from the aspects of theory and experimentation, the dynamic way analytical chemistry studies are evolving in the frame of chemistry degrees should not be surprising. Recently, many efforts have been made in order to include Green Chemistry principles to Education, also in the field of analytical chemistry, where twelve GAC principles play a main role. The understanding and awareness of these principles and other evolving related concepts requires special teaching of GAC as a part of curriculum at undergraduate and graduate levels. This article is focused on the main concepts and challenges of teaching GAC and also presents the current accomplishment in this field. In addition, teaching social responsibility in GAC is discussed. Several case studies are also presented as an example for the learners.

  • Green Analytical Chemistry: Summary of Existing Knowledge and Future Trends
    • Justyna Płotka-Wasylka
    • Agnieszka Gałuszka
    • Jacek Namieśnik
    2019

    Analysis of recent publications in green analytical chemistry shows the current trends and future needs in this area. The main issues are related with search for cheaper, more efficient, more accurate, greener and miniaturized alternatives. Miniaturization is perhaps, the most notable current trend in analytical chemistry. Rapid developments and improvements in instrumentation have led to impressive range of benchtop technology and portable devices. In addition, an important issue that has been explored by many authors is metrics of green analytical chemistry, such as Analytical Eco-Scale or Green Analytical Procedure Index. Implementation of interdisciplinary methods is an emerging trend in green analytical chemistry. Employment of multicriteria decision analysis, a technique which is used in environmental management, to green analytical chemistry is very popular and common trend. Another important issue that will determine the future of green analytical chemistry is education and popularization of this concept in the society. This chapter summarizes contemporary problems and gives future perspectives of Green Analytical Chemistry.

  • Green and equitable analytical chemistry
    • Renata Marcinkowska
    • Jacek Namieśnik
    • Marek Tobiszewski
    2019 Current Opinion in Green and Sustainable Chemistry

    Green analytical chemistry introduces the ideas of reduction ofanalytical activities impact on the environment. However, to bemore sustainable, analytical chemistry should include socialaspects in greater manner. In this light‘equitable’analyticalprocedures, which are easily available in terms of price andapplicability by everyday user, are developed. These positivetrends are observed as many procedures, based on commonlyused for nonanalytical purpose devices, are developed. Someexamples of methods based on smartphones, scanners, 3Dprinters, or espresso machines are presented herein. With thiscontribution, we want to stress that green analytical chemistryis not tantamount to sustainable analytical chemistry as it doesnot include social equity factors

  • Ground tire rubber thermo-mechanically devulcanized in the presence of waste engine oil as asphalt modifier
    • Yue Li
    • Aiqin Shen
    • Zhenghua Lyu
    • Shifeng Wang
    • Krzysztof Formela
    • Guangtai Zhang
    2019 CONSTRUCTION AND BUILDING MATERIALS

    Cross-linked elastomers network is main limitation for industrial usage of ground tire rubber (GTR) as asphalts’ and road pavements modifier. GTR was thermo-mechanically devulcanized via extrusion in the presence of waste engine oil (WEO) at temperature ranges from 150 to 280 °C. Combined impact of WEO content and extruder barrel temperature on the change of cross-linked structure of degraded GTR (DTGR) was investigated through sol fraction measurements and thermogravimetric analysis. Fourier-transform infrared spectroscopic analysis, storage stability, viscosity, temperature susceptibility and rheological properties of asphalt modified with DGTR were studied via infrared spectrometer, conventional tests, viscosity, dynamic shear rheology, dynamic mechanical analysis. Fluorescence microscopy was also applied to observe microstructure and the interfacial interaction between DGTR and asphalt. The results shown that the sol fraction of DGTR increases with the increase of WEO content, which results in low dynamic viscosity and storage modulus of the modified asphalts. Barrel temperature strongly affects the form of DGTR and final properties of modified asphalt. Modified asphalts with DGTR at barrel temperature in 180 °C and 210 °C show better rheological properties and broader operating temperature than that of at 280 °C, which is related to degradation of polymer main chain. In addition, 30 %wt. of DGTR content resulted in significant improvement rheological properties and storage stability of modified asphalt. Moreover, it was observed that higher content (above 40 %wt.) of DGTR causes the deterioration of performance properties of modified asphalts, due to the excessive quantities of undissolved rubber particles in asphalt.

  • Growth and Isolation of Large Area Boron‐Doped Nanocrystalline Diamond Sheets: A Route toward Diamond‐on‐Graphene Heterojunction
    • Robert Bogdanowicz
    • Mateusz Ficek
    • Michał Sobaszek
    • Adrian Nosek
    • Łukasz Gołuński
    • Jakub Karczewski
    • Andrés Jaramillo-botero
    • William A. Goddard III
    • Marc Bockrath
    • Tadeusz Ossowski
    2019 Full text ADVANCED FUNCTIONAL MATERIALS

    Many material device applications would benefit from thin diamond coatings, but current growth techniques, such as chemical vapor deposition (CVD) or atomic layer deposition require high substrate and gas‐phase temperatures that would destroy the device being coated. The development of freestanding, thin boron‐doped diamond nanosheets grown on tantalum foil substrates via microwave plasma‐assisted CVD is reported. These diamond sheets (measuring up to 4 × 5 mm in planar area, and 300–600 nm in thickness) are removed from the substrate using mechanical exfoliation and then transferred to other substrates, including Si/SiO2 and graphene. The electronic properties of the resulting diamond nanosheets and their dependence on the free‐standing growth, the mechanical exfoliation and transfer processes, and ultimately on their composition are characterized. To validate this, a prototypical diamond nanosheet–graphene field effect transistor‐like (DNGfet) device is developed and its electronic transport properties are studied as a function of temperature. The resulting DNGfet device exhibits thermally activated transport (thermionic conductance) above 50 K. Below 50 K a transition to variable range hopping is observed. These findings demonstrate the first step towards a low‐temperature diamond‐based transistor.

  • Guessing Intrinsic Forwarding Trustworthiness of Wireless Ad Hoc Network Nodes
    • Jerzy Konorski
    • Karol Rydzewski
    2019 Full text

    A novel node misbehavior detection system called GIFTED is proposed for a multihop wireless ad hoc network (WAHN) whose nodes may selfishly refuse to forward transit packets. The system guesses the nodes’ intrinsic forwarding trustworthiness (IFT) by analyzing end-to-end path performance rather than utilizing unreliable and incentive incompatible low-layer mechanisms. It can work with occasional IFT jumps, directional antennae, multichannel transmission, end-to-end encrypted packets, any single-path source routing protocol, and any number of selfish nodes; this makes it a valuable alternative to existing misbehavior detection schemes. GIFTED relies on approximate decomposition of a path equation system arising from successive performance reports from source nodes. The ability to near-perfectly guess IFT in the presence of various perturbations is demonstrated through Monte Carlo and time-true simulations, and compared with an existing weighted path trust scheme.

  • Guided Wave Propagation in Detection of Partial Circumferential Debonding in Concrete Structures
    • Beata Zima
    2019 Full text SENSORS

    The following article presents results of investigating the damage detection in reinforced concrete beams with artificially introduced debonding between the rod and cover, using a non-destructive method based on elastic waves propagation. The primary aim of the research was to analyze the possible use of guided waves in partial circumferential debonding detection. Guided waves were excited and registered in reinforced concrete specimens with varying extents of debonding damage by piezoelectric sensors attached at both ends of the beams. Experimental results in the form of time–domain signals registered for variable extent of debonding were compared, and the relationships relating to the damage size and time of flight and average wave velocity were proposed. The experimental results were compared with theoretical predictions based on dispersion curves traced for the free rod of circular cross-section and rectangular reinforced concrete cross-section. The high agreement of theoretical and experimental data proved that the proposed method, taking advantage of average wave velocity, can be efficiently used for assessing debonding size in reinforced concrete structures. It was shown that the development of damage size in circumferential direction has a completely different impact on wave velocity than development of debonding length. The article contains a continuation of work previously conducted on the detection of delamination in concrete structures. The proposed relationship is the next essential step for developing a diagnostics method for detecting debondings of any size and orientation.

  • Hard carbon derived from rice husk as low cost negative electrodes in Na-ion batteries
    • Maria Rybarczyk
    • Yunming Li
    • Mo Qiao
    • Yong-Sheng Hu
    • Magdalena Titirici
    • Marek Lieder
    2019 Journal of Energy Chemistry

    Here, we report the synthesis of hard carbon materials (RH) made from natural rice husk through a single pyrolysis process and their application as an anode in sodium-ion batteries. The studies show that the electrochemical properties of RHs are affected by the treatment temperatures, which determine the materials morphology, in particular, their degree of graphitization and extent of continuous channels (nanovoids). The latter are accessible to sodium ions and significantly contribute to charge storage capacity of the produced anodes. The RHs obtained at 1600 °C deliver the highest reversible capacity of 276 mAh g−1 mainly due to insertion of sodium ions into the nanovoids. This work deepens the basic understanding of the influence of the carbonization temperature on the sodium storage mechanism.

  • Heat recovery from the hybrid photovoltaic tile – experimental studies with the solar light simulator
    • Jan Wajs
    • Aleksandra Gołąbek
    • Roksana Bochniak
    • Dariusz Mikielewicz
    2019

    Considering the current development of micro-cogeneration energy sources, supported by the national prosumer policy and the act on the renewable energy sources, there is a great demand for the effective solar technologies. In this area, the photovoltaic cells with a combined conversion of the solar radiation energy into the electrical and thermal energy (PV/T cells) seem to be attractive. They are already widely available and treated as the classical solutions. On the other hand, the photocells forming the autonomous roof coverings (the photovoltaic tiles) are still kind of a novelty. In addition to the benefits of electricity generation in PV modules, the heat recovery from them could partially cover the heat demand in the residential or industrial buildings. The paper is dedicated to the hybrid solar systems (PV/T). The greatest attention was devoted to the analysis of heat recovery from the photovoltaic panel and an impact of this process on the efficiency of electricity generation. It is worth to emphasize that one of the very few models of the photovoltaic roof tiles available on the market has been tested. Experimental investigations were carried out on a dedicated experimental stand, equipped with a solar light simulator, designed for the needs of this research.

  • Heat transfer and pressure drop characteristics of the silicone-based plate heat exchanger
    • Tomasz Muszyński
    • Rafał Andrzejczyk
    • Il Wong Park
    • Carlos Alberto Dorao
    2019 Full text Archives of Thermodynamics

    The paper presents an experimental investigation of a silicone based heat exchanger, with passive heat transfer intensification by means of surface enhancement. The main objective of this paper was to experimentally investigate the performance of a heat exchanger module with the enhanced surface. Heat transfer in the test section has been examined and described with precise measurements of thermal and flow conditions. Reported tests were conducted under steady-state conditions for single-phase liquid cooling. Proposed surface modification increases heat flux by over 60%. Gathered data presented, along with analytical solutions and numerical simulation allow the rational design of heat transfer devices.

  • Heat transfer intensification by jet impingement – numerical analysis using RANS approach
    • Tomasz Kura
    • Elżbieta Fornalik-Wajs
    • Jan Wajs
    • Sasa Kenjeres
    2019 Full text E3S Web of Conferences

    Jet impingement is a method of the heat transfer enhancement applied in the engineering systems. The idea is to generate fast-flow fluid jet which impinge on the heated (or cooled) surface, causing significantly higher heat transfer rate. Although some flat surface jet impingement cases are described in the literature, the validated data is still limited. The reason is coming from the fact, that these flows are hydrodynamically complex. Therefore the numerical analysis is necessary to understand the phenomena, especially in the range of turbulent flow. The well-known and accurate method is Reynolds Averaged Navier-Stokes (RANS) approach. However, depending on the applied turbulence model, various results can be obtained. The reason is that the jet impingement strongly depends on the complex boundary layer effects and their resolving is still challenging for RANS models and until now it is their weakest point. In the paper, the hydrodynamic and thermal, numerical results of jet impingement are presented, depending on selected RANS based models. The aim was to indicate their ability to anticipate the turbulence parameters.

  • Heavy Duty Vehicle Fuel Consumption Modelling Based on Exploitation Data by Using Artificial Neural Networks
    • Oskar Wysocki
    • Lipika Deka
    • David Elizondo
    • Jacek Kropiwnicki
    • Jacek Czyżewicz
    2019 Full text

    One of the ways to improve the fuel economy of heavy duty trucks is to operate the combustion engine in its most efficient operating points. To do that, a mathematical model of the engine is required, which shows the relations between engine speed, torque and fuel consumption in transient states. In this paper, easy accessible exploitation data collected via CAN bus of the heavy duty truck were used to obtain a model of a diesel engine. Various polynomial regression, K-Nearest Neighbor and Artificial Neural Network models were evaluated, and based on RMSE the most relevant sets of parameters for the given algorithm were selected. Finally, the models were compared by using RMSE and Absolute Relative Error scores for 5 test samples. These represent the whole engine’s operating area. Apart from goodness of fit, the models were analyzed in terms of sensitivity to the size of the training samples. ANN and KNN proved to be accurate algorithms for modeling fuel consumption by using exploitation data. The ANN model was ranked best, as it required less observations to be trained in order to achieve an absolute relative error which was lower than 5%. A conventional method, i.e. polynomial regression, performed significantly worse than either the ANN or the KNN models. The approach presented in this study shows the potential for using easy accessible exploitation data to modeling fuel consumption of heavy duty trucks. This leads to the reduction of fuel consumption having a clear positive impact on the environment.

  • Heavy duty vehicle fuel consumption modelling using artificial neural networks
    • Oskar Wysocki
    • David Elizondo
    • Lipika Deka
    2019 Full text

    In this paper an artificial neural network (ANN) approach to modelling fuel consumption of heavy duty vehicles is presented. The proposed method uses easy accessible data collected via CAN bus of the truck. As a benchmark a conventional method, which is based on polynomial regression model, is used. The fuel consumption is measured in two different tests, performed by using a unique test bench to apply the load to the engine. Firstly, a transient state test was performed, in order to evaluate the polynomial regression and 25 ANN models with different parameters. Based on the results, the best ANN model was chosen. Then, validation test was conducted using real duty cycle loads for model comparison. The neural network model outperformed the conventional method and represents fuel consumption of the engine operating in transient states significantly better. The presented method can be applied in order to reduce fuel consumption in utility vehicles delivering accurate fuel economy model of truck engines, in particular in low engine speed and torque range.

  • Heavy Metals in Sediments of Urban Streams: Contamination and Health Risk Assessment of Influencing Factors
    • Ewa Wojciechowska
    • Nicole Nawrot
    • Jolanta Walkusz-miotk
    • Karolina Matej-Łukowicz
    • Ksenia Pazdro
    2019 Full text Sustainability

    Sediments of two urban streams in northern Poland outflowing to the Baltic Sea were assessed to explain the spatial variation in relation to urbanization level of the catchment, the role of retention tanks (RTs) and identification of pollution level. During the 3 month period of investigation sediment samples were collected from the inflow (IN) and outflow (OUT) of six RTs located on streams for flood protection. Six heavy metals (HMs) were investigated: Cu, Pb, Zn, Cd, Ni, Cr. The assessment of four geochemical enrichment indices used to quantify contamination of HMs in the sediments at IN and OUT samples was carried out. Contamination factor (CF), pollution load index (PLI), geoaccumulation index (Igeo) and potential ecological risk (RI) were calculated and the indices usefulness was assessed. Also, the hazard quotient (HQ) was calculated to assess health risk associated with dredging works. In sediments from RTs where paved surfaces constituted more than 70% of the catchment the HMs concentrations were from one to three times higher for Ni and from two to 143 times higher for Cu in comparison to soft catchment results. The extremely high Cu concentration (1114 mg/kg d.w.) found in sediments at RT Orłowska IN was most likely associated with large area of roofs covered with copper sheet. Calculation of CF, PLI, Igeo, RI, HQ indicators allows for a complex and multi-dimensional assessment of sediment status. Among these, CF and PLI classified the analyzed sediments as most polluted. Basing on the sedimentary HMs concentrations the health risk level via dermal exposure pathway was assessed as low.

  • Heterogeneous oxidation of highly boron-doped diamond electrodes and its influence on the surface distribution of electrochemical activity
    • Jacek Ryl
    • Łukasz Burczyk
    • Artur Zieliński
    • Mateusz Ficek
    • Artur Franczak
    • Robert Bogdanowicz
    • Kazimierz Darowicki
    2019 Full text ELECTROCHIMICA ACTA

    The electrochemical active surface area (EASA) of polycrystalline boron-doped diamond (BDD) electrodes is heterogeneous and can be affected by numerous factors. There is a strong need for proper consideration of BDD heterogeneity in order to improve this material's range of application in electrochemistry. Localized changes in surface termination due to the influence of oxidation agent result in increased surface resistance. The observed behavior of this characteristic feature varies among individual grains, depending on their crystallographic orientation. Still, there is not much information about this key factor in terms of its influence on the electrochemical response of BDD. In this study we compared two approaches towards BDD surface oxidation, namely: anodic polarization at potentiostatic and potentiodynamic conditions. The surface impedance measurements via Nanoscale Impedance Microscopy (NIM) allowed the confirmation of diversified propensity for the modification of surface termination in BDD. We showed that the NIM studies provide a deep understanding on the electrical characterization and variation of surface resistance in BDD electrodes. In order to evaluate the actual heterogeneity of electrochemical activity distribution, voltammetry, dynamic electrochemical impedance spectroscopy (DEIS) and scanning electrochemical microscopy (SECM) studies were performed. For each investigated electrode, departure from the Randles-Sevcik equation was observed, with its level depending on the surface heterogeneity and oxidation treatment, justifying the standardization of pre-treatment procedure and development of non-standard model for diffusion transport in proximity of BDD electrode.

  • High performance super-twisting sliding mode control for a maritime autonomous surface ship (MASS) using ADP-Based adaptive gains and time delay estimation
    • Hossein Nejatbakhsh Esfahani
    • Rafał Szłapczyński
    • Mohammad Hossein Ghaemi
    2019 Full text OCEAN ENGINEERING

    This research addresses two kinds of problems related to optimal trajectory tracking of a Maritime Autonomous Surface Ship (MASS): those caused by the time-varying external disturbances including winds, waves and ocean currents as well as those resulting from inherent dynamical uncertainties. As the paper shows, an accurate and robust optimal controller can successfully deal with both issues. An improved Optimal Adaptive Super-Twisting Sliding Mode Control (OAST-SMC) algorithm is proposed here as a robust optimal adaptive strategy. In this strategy, in order to improve performance of the standard super-twisting approach, we apply an Approximate Dynamic Programming (ADP)-based optimal tuning of gains and an underlying concept based on Time Delay Estimation (TDE). An ADP algorithm is implemented using an actor-critic neural network to deal with the curse of dimensionality in Hamilton–Jacobi–Bellman (HJB) equation. The critical role of TDE part in this algorithm is estimating the impact of disturbances and uncertainties on the MASS model. The results have shown that OAST-TDE significantly outperforms the ST-TDE and AST-TDE algorithm in terms of the optimal control efforts. Also, compared with a Nonlinear Model Predictive Control (NMPC), proposed controller meets the optimal control efforts and accurate tracking concurrently.

  • High Performance Tubular Heat Exchanger with Minijet Heat Transfer Enhancement
    • Jan Wajs
    • Dariusz Mikielewicz
    • Elżbieta Fornalik-Wajs
    • Michał Bajor
    2019 Full text HEAT TRANSFER ENGINEERING

    In the paper, the original cylindrical heat exchanger with minijets (MJHE) was introduced. The systematic experimental analysis of the prototype heat exchanger was described with special attention paid to such parameters as the heat transfer effectiveness, heat transfer rates, overall heat transfer coefficients, and pressure drop. The heat transfer coefficients were determined based on Wilson plot method, the most suitable approach for heat transfer coefficient determination in exchangers of complex geometry. The thermal-hydraulic characteristics of the in-house manufactured prototype of MJHE in water–water and gas–water configuration are also presented. The experimental results were compared with the predictions from well-known correlations found in the published research papers dedicated to the free-surface and submerged types of jets.

  • High temperature oxidation behavior of SUS430 SOFC interconnects with Mn-Co spinel coating in air
    • Chuan Jia
    • Yuhao Wang
    • Sebastian Molin
    • Yongliang Zhang
    • Ming Chen
    • Minfang Han
    2019 JOURNAL OF ALLOYS AND COMPOUNDS

    In this study, SUS430 alloy is evaluated for its high temperature corrosion properties as a possible material for interconnects of solid oxide fuel cells (SOFCs). Samples are coated with Mn-Co by commercial physical vapor deposition (PVD) process and oxidized in air for 1250 h at 800 °C. A dense cubic Mn-Co-Fe spinel layer is formed on the surface, showing great effect on corrosion reduction compared with the samples without coating. A corrosion rate constant of 1.22 × 10−14 g2 cm−4 s−1 is presented in this study for the coated samples, with an area specific resistance (ASR) of around 31 mΩ cm2. After the experiment, microstructures of the samples are analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), which shows that the SUS430 alloy with Mn-Co coating can be considered as one of the low-cost material for the interconnects of SOFCs with good performance.

  • High-efficiency mini and micro heat exchangers for dispersed power generation
    • Jan Wajs
    • Dariusz Mikielewicz
    2019

    Taking into account the dispersed systems technologies and their development, the ORC systems seem to be promising technology amongst various micro-CHP domestic units (electrical power production below 10 kWe), however practical realization of the ORC cycle in a micro-scale is technically challenging. The system consists in devices such as the vapour generation unit (boiler), expansion device and heat exchangers. Each of them should be of high performance so that the system as a whole could work efficiently. This is the reason why novel constructions of heat exchangers or heat transfer enhancement mechanisms are looked for in relation to the evaporator, condenser or regenerator. In the present paper the own construction of compact heat exchangers (plate-type and cylindrical constructions) with microjets and with minichanels are proposed. They were designed on the basis of several years of experiences, for the needs of domestic ORC system and other dispersed energy generation technologies. The features of mentioned above heat exchangers are discussed together with the flow and thermal characteristics of their prototypes. As a summary, the experimental studies of the authors domestic ORC unit equipped with prototype minichannel heat exchangers are also presented.

  • Highlights from RNDM 2018 – 10th Anniversary Workshop on Resilient Networks Design and Modeling
    • Jacek Rak
    • Poul Heegaard
    • Bjarne Helvik
    2019 IEEE COMMUNICATIONS MAGAZINE

    Artykuł prezentujący relację z workshopu RNDM 2018

  • Highly effective asphaltene-derived adsorbents for gas phase removal of volatile organic compounds
    • Maksymilian Plata-Gryl
    • Malwina Momotko
    • Sławomir Makowiec
    • Grzegorz Boczkaj
    2019 Full text SEPARATION AND PURIFICATION TECHNOLOGY

    A novel nitrated asphaltene-derived adsorbent (Asf-Nitro) was prepared using facile isolation and modification procedures. The successful modification was confirmed by Fourier-transform infrared spectroscopy (FTIR). The nitrated adsorbent was evaluated in terms of dispersive and specific interactions, Lewis acid-base properties and adsorption isotherms by means of inverse gas chromatography (IGC). Nitration was found to be extremely effective in enhancing adsorption properties of asphaltenes towards variety of chemical compounds. Asf-Nitro adsorbent exhibits superior dispersive interactions (197.50 ± 1.12 mJ m-2 at 423 K), as compared to unmodified asphaltenes, which are comparable with activated carbons, zeolites or alumina. Examination of the specific interactions revealed a shift from basic to acidic character of the surface, what will be beneficial for adsorption of alkaline gases. Additionally, adsorption isotherms revealed that developed surface properties of the Asf-Nitro results in more than doubled monolayer adsorption capacity. Obtained results demonstrates the applicability of the asphaltene-derived materials in adsorption processes as highly effective and low cost adsorbents. This studies revealed a highly effective adsorption of environmentally important VOCs, e.g. n-butanol (odorous compound), trichloromethane (chlorinated hydrocarbon) and benzene (carcinogenic).

  • High-temperature heat pumps – potential technology for heat recovery and production of process heat
    • Dariusz Mikielewicz
    • Jan Wajs
    2019

    In the paper, the high temperature vapour compressor based heat pump with a selection of working fluids, both perspective and ecological ones, is considered. Such system is not yet commercially available on the market and in author’s opinion it has significant potential for various applications. In the presented analysis it was assumed that the heat source has a temperature of 50oC and the temperature lift is 60, 80 and 100K respectively. Such temperature lift is a requirement for perspective applications. On the basis of obtained results the fluid working temperatures, heat rates, coefficient of performance of proposed solution as well as second law analysis have been determined. They confirm the potential for implementation in high temperature heat pumps in energy engineering area. Especially ethanol as working fluid seems to outperform other fluids.

  • High-temperature kinetics study of 430L steel powder oxidized in air at 600–850 °C
    • Jakub Karczewski
    • Tomasz Brylewski
    • Tadeusz Miruszewski
    • K. H. Andersen
    • Piotr Jasiński
    • Sebastian Molin
    2019 CORROSION SCIENCE

    The 430L stainless steel powder with a mean particle size of 95 μm was studied to determine its high-temperature oxidation properties. Continuous thermogravimetric measurements were carried out for 100 h in air at temperatures in the range of 600–850 °C. Even though a considerable amount of Cr (up to ˜5 wt.% Cr) inside the grains was depleted – especially inside small grains – no breakaway oxidation was observed. This indicates that both the remaining Cr and the formed chromia scale remained protective with regard to the metallic core until the Cr concentration reached very low levels.

  • High-temperature oxidation of the Crofer 22 H ferritic steel with Mn1.45Co1.45Fe0.1O4 and Mn1.5Co1.5O4 spinel coatings under thermal cycling conditions and its properties
    • M Bednarz
    • Sebastian Molin
    • Michał Bobruk
    • M Stygar
    • E Długoń
    • M Sitarz
    • Tomasz Brylewski
    2019 MATERIALS CHEMISTRY AND PHYSICS

    The aim of the presented study was to deposit protective-conducting Mn1.45Co1.45Fe0.1O4 and Mn1.5Co1.5O4 spinel coatings on the Crofer 22 H ferritic steel by means of electrophoresis and to evaluate their physicochemical properties after high-temperature oxidation under thermal cycling conditions. When the Crofer 22 H steel – whether uncoated or coated with the two spinels – was oxidized in 48-h cycles involving a temperature of either 750 or 800 °C, its oxidation kinetics approximately obeyed the parabolic rate law. The oxidation rate observed for uncoated steel was higher than that for the studied coating/steel systems. The Fe-doped spinel coating material improved the oxidation resistance of steel to a higher degree than the undoped spinel coating. The obtained bulk spinels exhibited a regular phase composition and high electrical conductivity, while the Mn1.45Co1.45Fe0.1O4 and Mn1.5Co1.5O4 coatings were dual-phase, compact, and exhibited good adhesion to the metallic substrate. The area-specific resistance values measured for the steel/coating systems indicate that the coatings significantly improve the electrical properties of the studied ferritic steel, especially at 800 °C. The conducted research confirmed the suitability of the Mn1.45Co1.45Fe0.1O4 and Mn1.5Co1.5O4 spinels as coatings on the Crofer 22 H ferritic steel to be applied in the production of interconnects used in intermediate-temperature SOFCs.

  • High-temperature properties of titanium-substituted yttrium niobate
    • Aleksandra Mielewczyk-Gryń
    • Piotr Winiarz
    • Sebastian Wachowski
    • Maria Gazda
    2019 JOURNAL OF MATERIALS RESEARCH

    he defect fluorite titanium-doped yttrium niobate samples Y3Nb1−xTixO7−δ have been synthesized and investigated by the means of high-temperature X-ray diffraction, dilatometry, and thermogravimetry. Thermal expansion coefficients (TECs) as well as chemical expansion coefficients for material with 5, 10, and 15 mol% of titanium were determined. All investigated samples exhibit chemical contraction caused by Ti doping. The values of TECs obtained by two different methods show similar results, which suggests the isotropy of the polycrystalline ceramic. Thermogravimetric studies have shown that all of the compositions exhibit a mass increase upon being exposed to a humid air atmosphere. The total proton concentration calculated on the basis of these results was in the range of 0.1 mol%. Moreover, titanium content influences chemical expansion coefficient, water uptake, and protonic defects concentration, whereas it does not significantly affect the values of TECs

  • Historia i materialne relikty fortyfikacji Westerplatte sprzed 1920 r.
    • Arkadiusz Woźniakowski
    2019

    Z uwagi na swoje położenie Westerplatte od momentu uformowania się wyspy, a następnie półwyspu, miało kluczowe znaczenie dla obrony wejścia do portu w Gdańsku. Pierwsze znane nowożytne fortyfikacje na terenie Westerplatte to oszańcowany obóz warowny wojsk pruskich z końca XVII w., ale najintensywniejsza rozbudowa umocnień nastąpiła od połowy XIX w., kiedy położono większy nacisk na zabezpieczenie ujścia Wisły. Od lat osiemdziesiątych XIX w. w Gdańsku rozbudowywano już tylko fortyfikacje nadbrzeżne, z których wiele znalazło się na Westerplatte. Przechodziły one wiele przemian związanych przede wszystkim z rozwojem uzbrojenia i taktyki, ale także naturalną działalnością morza, rozwojem przemysłu portowego i zmianami geopolitycznymi. Celem artykułu jest prześledzenie rozwoju i zmian w układzie przestrzennym fortyfikacji Westerplatte do momentu utworzenia Wolnego Miasta Gdańska oraz identyfikacja zachowanych reliktów w świetle najnowszych badań i źródeł kartograficznych. Jest to przyczynek do badań nad mniej znanym rozdziałem w militarnej historii tego miejsca, jeszcze przed ustanowieniem Wojskowej Składnicy Tranzytowej.

  • History and Milestones of Green Analytical Chemistry
    • Justyna Płotka-Wasylka
    • Magdalena Fabjanowicz
    • Kaja Kalinowska
    • Jacek Namieśnik
    2019

    Due to the increased environmental consciousness, Green Analytical Chemistry (GAC) is an important concept steadily gaining popularity, as its implementation facilitates the decrease the detrimental effect analytical chemistry methodologies may have on the environment. In this chapter, a brief overview of the history of Green Analytical Chemistry (GAC) and its milestones was given. Emphasis has been put on the beginnings of green chemistry awareness and on the possibilities of increasing and evaluating the greeness of both currently used and designed analytical chemistry methodologies. In addition, the prospects of implementation of 12 principles of Green Analytical Chemistry have been briefly described.

  • Home Sweet Home. Connecting the dots for healthy evening residential illumination
    • Karolina Zielińska-Dąbkowska
    2019 Full text ARC Lighting In Architecture

    During the twentieth century, lighting designers would commonly use incandescent light sources for residential homes as they provided a visual comfort, with high quality colour rendering properties, along with relaxing ambient atmosphere. Unfortunately, it’s now difficult to buy incandescent light sources because they have been banned in many countries (https://bit.ly/2GwN2Wv). This article addresses some of the challenges in regards to health, brought about by the changeover to new LEDs and other related technologies, and tries to offer some context on how to keep up with these rapid transformations. While we know it’s necessary to limit blue-rich light at night (as it prevents melatonin production and impaires nocturnal sleep), and that it’s important to maximise exposure to the blue wavelength of light in the morning (to trigger circadian timing, increase alertness), there are other issues that are misunderstood and often ignored. This includes flicker from LEDs and electromagnetic fields (EMFs), which can be produced by smart home lighting technology.

  • Homo- i heteroleptyczne związki koordynacyjne metali przejściowych z pochodnymi imidazolu, ze szczególnym uwzględnieniem 4(5)-(β-hydroksyetylo)imidazolu – badania strukturalne i spektroskopowe w ciele stałym i roztworze
    • Piotr Maślewski
    2019 Full text

    Rozprawa doktorska porusza zagadnienia związane z syntezą oraz właściwościami związków koordynacyjnych metali przejściowych z pochodnymi imidazolu. Główna uwaga poświęcona jest 4(5)-(β-hydroksyetylo)imidazolowi — występującemu naturalnie ligandowi, będącemu hydroksylowym analogiem histaminy, o zwyczajowej nazwie histaminol. Praca skupia się na ligandach zbliżonych strukturalnie do 4(5)-(β-hydroksyetylo)imidazolu oraz wykazującymi tę samą co on zdolność do chelatacji jonów metali w związkach kompleksowych. W ramach pracy przeprowadzono syntezę trzech ligandów imidazolowych, a następnie wykorzystano je do otrzymania związków kompleksowych z wybranymi jonami metali, przeważnie z tymi które występują w układach biologicznych. Za pomocą rentgenografii strukturalnej uzyskano struktury krystalograficzne dwóch otrzymanych ligandów oraz czternastu nowo poznanych związków koordynacyjnych z 4(5)-(β-metoksyetylo)imidazolem, 4(5)-(β-hydroksyetylo)imidazolem, 2,2’-bis(4,5-dimetyloimidazol)em oraz 1H-imidazolem. Oznaczono stałe trwałości związków koordynacyjnych 4(5)-(β-hydroksyetylo)imidazolu z wybranymi jonami metali w roztworach wodnych oraz prześledzono proces ich tworzenia za pomocą metod potencjometrycznych. Dzięki uzyskanym wynikom udało się scharakteryzować właściwości badanych ligandów oraz tworzonych przez nie kompleksów zarówno w ciele stałym jak i roztworze.

  • Host and pathogen factors in Klebsiella pneumoniae upper urinary tract infections in renal transplant patients
    • Justyna Gołębiewska
    • Beata Krawczyk
    • Magdalena Wysocka
    • Aleksandra Ewiak
    • Jolanta Komarnicka
    • Marek Bronk
    • Bolesław Rutkowski
    • Alicja Dębska-ślizień
    2019 Full text JOURNAL OF MEDICAL MICROBIOLOGY

    Purpose . To analyse the role of virulence factors (VFs) and host in Klebsiella pneumoniae upper urinary tract infections (UTIs) in renal transplant (RTx) recipients. Methodology. Clinical and demographic data were registered prospectively. Phylogenetic background of K. pneumoniae isolates was analysed by PCR melting profiles (MP) and the following VFs genes: fimH-1, uge, kpn, ycfM, mrkD, rmpA, magA, hlyA, cnf-1, irp-1, irp-2, fyuA, entB, iutA, iroN by PCR. Results. We studied urine cultures and clinical data from 61 episodes of K. pneumoniae UTI in 54 RTx recipients. There were 32 cases of AB (53%), 10 cases of lower UTI (16%), 19 cases of AGPN (31%), including six cases of bacteraemia. In total, 74 % of strains were extended-spectrum beta-lactamase+, and there were two carbapenemase-producing strains. PCR MP typing showed a diverse population with 52 different genetic profiles of K. pneumoniae . Analysis of the DNA profiles indicated 45 unrelated, unique genotypes and 7 related (16 isolates from 15 patients) genotypes. Urine flow impairment emerged as an independent predictor of K. pneumoniae upper UTIs (OR 14.28, CI 2.7–75.56, P 0.002), while we did not find any association between the profile of VFs and developing upper UTIs. The prevalence of the uge gene was lower in RTx patients on everolimus when compared to isolates from patients not receiving mTOR inhibitors (33.3 % vs 82.8 % P<0.05). Conclusions . K. pneumoniae upper UTI may be a marker of urine flow impairment. Bacterial VFs could not discriminate between upper and lower UTIs. However, immunosuppression may influence the selection of particular VFs.

  • How green are ionic liquids? – A multicriteria decision analysis approach
    • Marta Bystrzanowska
    • Pena-pereira Francisco
    • Łukasz Marcinkowski
    • Marek Tobiszewski
    2019 Full text ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY

    Due to various desirable physicochemical properties, ionic liquids (ILs) are still gaining in popularity. ILs have been recurrently considered green solvents. However, environmental, health and safety assessments of ILs have raised certain doubts about their benignness, and their greenness status is currently unclear. To clarify the situation on their greenness, we perform a comprehensive assessment of more than 300 commercially available ILs. We apply multicriteria decision analysis, the tool that allows ranking many alternatives according to relevant criteria. They are toxicity towards various organisms, biodegradability, hazard statements and precautionary measures during their handling. We incorporated organic solvents to rankings, as their greenness is better described, so they serve as greenness reference points. The ranking results obtained considering the whole set of criteria show that ILs are placed between recommended polar solvents and problematic/undesirable non polar organic solvents in terms of greenness. However, the exclusion of toxicity data due to unavailability of endpoints results in assessment of ILs as greener than most of organic solvents.

  • How to achieve sustainability?-Employee's point of view on company's culture and CSR practice
    • Wioleta Kucharska
    • Rafał Kowalczyk
    2019 Full text Corporate Social Responsibility and Environmental Management

    The people are the company. This study aims to examine the structure of relationships between company culture, performance, corporate social responsibility (CSR), and reputation, as seen from the employee's perspective, to determine which company culture factors most influence CSR practice and, as a result, sustain a company's development and improve its performance. To accomplish this goal, we conducted a survey among employees of Polish construction companies regarding CSR practices in their organizations. We applied a structural equation model based on 539 individual cases. For a better understanding of the employee's perception of CSR practice, the model included control variables such as company size and position in the company. Our findings suggest that company reputation is a strong mediator of the CSR practice and company performance relationship, and the cultural dimension of long‐term orientation has the greatest influence on CSR practice. The study advances the knowledge on the subject using a microlevel approach to stakeholders' engagement in CSR by exploring the personalized employee‐centric view of organizational culture, CSR practice, and company reputation to sustain a company's development and improve its performance.

  • How to stop salami science: promotion of healthy trends in publishing behavior
    • Jarosław Wawer
    2019 Accountability in Research-Policies and Quality Assurance

    The career of scientists often depends on the number of their published works. This fact leads to the overproduction of low quality papers burying the important articles and making the knowledge less accessible. One of the methods to counteract these negative aspects might lie in the promotion of healthy trends in publishing behavior. In the present work, the theoretical analysis of a new bibliometric measure is presented, and its potential impact on the publishing strategies is carefully discussed.

  • Human Centric Lighting. The New X Factor?
    • Karolina Zielińska-Dąbkowska
    2019 Full text ARC Lighting In Architecture

    We live in challenging times, and one could even claim we’re experiencing a revolution in lighting with LED technology taking over the world. Part of this rapid change involves a concept called Human Centric Lighting (HCL). In Frankfurt this year, during Light+Building, it was the buzzword, with nearly every second manufacturer’s stand claiming they had figured out the special formula necessary to create perfect HCL illumination. But how can such claims be legitimate when we know so little about the full and complex impact of artificial lighting on human biology, let alone how to responsibly apply this new approach?

  • Human Computer Interface for Tracking Eye Movements Improves Assessment and Diagnosis of Patients With Acquired Brain Injuries
    • Michał Lech
    • Michał Tomasz Kucewicz
    • Andrzej Czyżewski
    2019 Full text Frontiers in Neurology

    One of the first clinical signs differentiating the minimally conscious state from the vegetative state is the presence of smooth pursuit eye movements occurring in direct response to moving salient stimuli. Glasgow Coma Scale (GCS) is one of the most commonly used diagnostic tools for acute phase assessment of the level of consciousness, together with a neurological examination. These classic measures are limited to qualitative neurological examination without more quantitative measures provided from e.g., tasks with tracking position of the gaze. Among this and other limitations, it is prone to a relatively high rate of misdiagnosis. Here, we developed an interface for gaze tracking to enhance the assessment of consciousness in 10 patients with acquired brain injuries. According to the acute phase GCS assessment, nine of them were considered unaware and below the minimally conscious state. Chronic neurological examination confirmed six of them below the minimally conscious state. Our new Human Computer Interface (HCI) revealed that six patients were conscious enough to complete at least one of the gaze tracking tasks. Among these six patients, one was originally diagnosed as remaining in a vegetative state and one in coma. The patient diagnosed as remaining in a chronic vegetative state scored six GCS points acutely. Following assessment with our HCI the patient was re-diagnosed with a possible locked-in syndrome. Our HCI method provides a new complementary tool for clinical assessment of patients suffering from disorders of consciousness.

  • Human verbal memory encoding is hierarchically distributed in a continuous processing stream
    • Michał Tomasz Kucewicz
    • Krishnakant Saboo
    • Brent M. Berry
    • Vaclav Kremen
    • Laura R. Miller
    • Fatemeh Khadjevand
    • Cory S. Inman
    • Paul A. Wanda
    • Michael R. Sperling
    • Richard Gorniak
    • Kathryn A. Davis
    • Barbara C. Jobst
    • Bradley Lega
    • Sameer A. Sheth
    • Daniel S. Rizzuto
    • Ravishankar K Iyer
    • Michael J. Kahana
    • Gregory A. Worrell
    2019 Full text eNeuro

    Processing of memory is supported by coordinated activity in a network of sensory, association, and motor brain regions. It remains a major challenge to determine where memory is encoded for later retrieval. Here we used direct intracranial brain recordings from epilepsy patients performing free recall tasks to determine the temporal pattern and anatomical distribution of verbal memory encoding across the entire human cortex. High gamma frequency activity (65-115 Hz) showed consistent power responses during encoding of subsequently recalled and forgotten words on a subset of electrodes localized in 16 distinct cortical areas activated in the tasks. More of the high gamma power during word encoding, and less power before and after the word presentation, was characteristic of successful recall and observed across multiple brain regions. Latencies of the induced power changes and this subsequent memory effect between the recalled and forgotten words followed an anatomical sequence from visual to prefrontal cortical areas. Finally, the magnitude of the memory effect was unexpectedly found to be the largest in selected brain regions both at the top and at the bottom of the processing stream. These included the language processing areas of the prefrontal cortex and the downstream visual areas at the junction of the occipital and temporal lobes. Our results provide evidence for distributed encoding of verbal memory organized along a hierarchical posterior-to-anterior processing stream.

  • Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
    • Jacek Łubiński
    • Henryk Olszewski
    2019 Full text Polish Maritime Research

    In the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading, as well as the influence of vibrations, buoyancy and accompanying mass of water. Both commercial and open source mathematical modeling software which is available nowadays allows for cost effective and flexible implementation of advanced models for offshore industrial structures with high level of credibility and safety. The models can be built to suit task-specific requirements and evaluated on the basis of the selected criterial system best suited to the needs of the customer. Examples of methodology for environmental and structural model development are presented, along with simulation results covering a wide scope of data, ranging from stress and deformation to resonant characteristics and issues of technological feasibility

  • Hybrid System for a Person Tracking in Harsh Indoor Environments
    • Piotr Rajchowski
    • Krzysztof Cwalina
    • Jarosław Sadowski
    • Jacek Stefański
    2019

    In the article, the prototype of a system for a person tracking in a harsh indoor environment, especially when no other commercially available radiolocalization system can be used, was briefly described. The prototype realizes the data fusion, i.e. combines data from inertial and environmental sensors and radio distance measurements to estimate the position of a moving person. It is worth noting that the concept and practical realization of the system was consulted with Maritime Regional Unit of Polish Border Guard.

  • Hydraulic analysis of causes of washout of Gdynia-Orłowo seashore during the flood in the Kacza river estuary
    • Michał Szydłowski
    2019 Full text Polish Maritime Research

    In July 2016 in the Three-city agglomeration a rainfall episode of over a day duration and 150 mm summary rainfall height, occurred. This situation, extreme as for Polish conditions, caused significant freshets in rivers and streams running into Gdansk Bay, the Baltic Sea, and serving as collectors of rainfall waters for the sea-coast towns. In many areas of the Three-city flood phenomena and overflows took place. The flood also occurred in the catchment area of the Kacza river in Gdynia. The passing of flood water rise caused damage of many infrastructure objects located along the river valley. The estuary section of the river suffered most, especially sea-shore belt together with beach around the estuary which were significantly washed out. In this paper an approach was made to answer to the question on direct causes of the situation which occurred at the estuary of the Kacza river. To this end, there was worked out a hydrodynamic model of the considered section of the river, based on the solving of two-dimensional differential motion equations of free-surface liquid, and simulations of water flow propagation along the river’s valley were performed for a few variants of hydraulic engineering infrastructure of river bed. Numerical hydraulic analysis made it possible to determine a role of the hydraulic engineering objects in forming the flood water rise as well as their impact on location and range of washout zones of sea-shore belt.

  • Hydraulic resistance analyses of selected elements of the prototype Stirling engine
    • Mariusz Furmanek
    • Jacek Kropiwnicki
    2019 Full text Archives of Thermodynamics

    The paper presents the results of simulation tests of hydraulic resistance and temperature distribution of the prototype Stirling alpha engine supplied with waste heat. The following elements were analyzed: heater, regenerator and cooler. The engine uses compressed air as a working gas. Analyses were carried out for three working pressure values and different engine speeds. The work was carried out in order to optimize the configuration of the engine due to the minimization of hydraulic resistance, while maintaining the required thermal capacity of the device. Preliminary tests carried out on the real object allowed to determine boundary and initial conditions for simulation purposes. The simulation assumes that there is no heat exchange between the regenerator and the environment. The solid model used in simulation tests includes the following elements: supply channel, heater, regenerator, cooler, discharge channel. Due to the symmetrical structure of the analyzed elements, simulation tests were carried out using 1/6 of the volume of the system.

  • Hydro Power Plant in the Process of Voltage Control in the Electric Power System and the System Restoration
    • Zbigniew Lubośny
    • Maciej Łosiński
    2019 Full text Acta Energetica

    The article covers selected issues related to the share of hydroelectric power in the process of rebuilding the power system after black-out and voltage control during that process. Selected results of measurements made during the creation of the transmission chain for the need to start a block of a thermal power plant from a hydroelectric power plant were presented.

  • Hydromechaniczne aspekty projektowania statków z napędem azymutalnym
    • Maciej Reichel
    2019

    W monografii przedstawiono ocenę stanu dotychczasowej wiedzy dotyczącej hydromechanicznych aspektów projektowania statków z pędnikami azymutalnymi, dostępnej w światowym otwartym obiegu wiedzy. Praca prezentuje proces projektowania, w tym optymalizacji kształtu kadłuba statku z napędem azymutalnym. Omówiono wpływ zmian kształtu kadłuba na właściwości manewrowe statków z takim typem napędu, ze szczególnym uwzględnieniem stateczności kursowej. Głównym jednak elementem pracy są te etapy spirali projektowej, które wprost są związane z zagadnieniami hydromechaniki. Monografia zawiera opis procesu optymalizacji właściwości napędowych i manewrowych statków z pędnikami azymutalnymi wraz z szerokim opisem prób modelowych służących optymalizacji. Osobny rozdział poświęcono charakterystykom hydrodynamicznym pędników azymutalnych w warunkach wody otwartej. Zwrócono uwagę na odmienne znaczenie sił napędowych i sił sterujących generowanych na pędnikach azymutalnych w procesie projektowania. Monografia zawiera najnowsze informacje dotyczące projektowania statków oraz pędników azymutalnych, dostępne w światowej literaturze. Uwzględnia ona zarówno prace badawcze wykonywane przez międzynarodowe środowisko hydromechaników, jak i prace autora realizowane przez wiele lat w polskich i zagranicznych ośrodkach naukowych. W podsumowaniu monografii zaprezentowano krytyczną ocenę procedur badania i projektowania statków z pędnikami azymutalnymi oraz przyszłe tematy badawcze, które według autora powinny zostać podjęte w najbliższym czasie w celu podniesienia jakości procesu projektowania.

  • Hydrothermal synthesis of vanadium ammonium compounds – the crucial role of the pressure
    • Małgorzata Nadolska
    • Marta Prześniak-Welenc
    • Andrzej Nowak
    • Kamila Sadowska
    2019

    Due to the structural diversity and chemical activity, vanadium oxides and their derivatives are continuingly in the great interest of scientist. In a large family of vanadium compounds, one of the most interesting are ammonium vanadates (with the general formula (NH4)xVyOz). They have received much attention because of their promising application as cathode material in mono- and multivalent-ion batteries [1]. Hydrothermal synthesis is already established as an efficient method to produce ammonium vanadates with various morphology, structure and chemical composition. The aforementioned parameters determined the electrochemical properties of the material and could be tailored by varying synthesis parameters (e.g. temperature, time, pH) [2]. In presented work, the effect of the initial hydrothermal synthesis pressure on the final product was studied for the first time. All samples were prepared via hydrothermal method in the autoclave, in which the water solution of NH4VO3 and C2H2O4 was heated to 180°C for 8h. In order to study the pressure effect, the same procedure was repeated without the initial pressure and with pre-pressurized the autoclave to 5, 25, 50 bars. The obtained samples were fully characterized with SEM, TEM, XRD, XPS, FTIR and TGA. Results indicate that the initial pressure affects both the morphology and the structure of samples and cannot be neglected in the synthesis. Moreover, the electrochemical performance of the as-prepared samples as lithium-ion cathode materials were investigated. It was found that sample obtained with higher pressure exhibit higher specific capacity and cyclic stability. FIGURE 1. Comparison of ammonium vanadates obtained with different initial hydrothermal synthesis pressure. Acknowledgements Part of this work was supported by the National Science Centre (No. 2017/01/X/ST5/01415). References [1] Y. Liu et al.J., Mater. Sci., 53(3),pp. 2045–2053, 2018 [2] S. Sarkar et al., Electrochim. Acta, vol. 132, pp. 448–456, 2014.

  • Hyperbolic heat conduction at a microscopic sliding contact with account of adhesion-deformational heat generation and wear
    • Oleksii Nosko
    2019 Full text INTERNATIONAL JOURNAL OF THERMAL SCIENCES

    Different non-Fourier models were proposed to simulate temperatures in materials subjected to extremely fast thermal disturbances, when the speed of heat propagation should be concerned. The present study investigated temperature and heat balance at a microscopic sliding contact during a single frictional interaction based on the Cattaneo-Vernotte hyperbolic heat conduction equation. Two fundamental features of friction, namely, adhesion-deformational heat generation and wear, were taken into account. By applying the Laplace transform approach, non-stationary temperature expressions were derived for the hyperbolic and classical parabolic heat conduction equations. Parametric analysis was then done for parameter ranges typical of brake materials. It was found that the hyperbolic heat conduction generally results in a higher temperature at the sliding surface compared to the parabolic heat conduction. The influence of the heat propagation speed can be significant for thermal relaxation time of the order above microsecond. It becomes stronger with an increase in the contribution of the adhesive heat generation. Another finding obtained is that a considerable fraction of heat is removed from the contact zone along with wear debris, resulting in a lower temperature. This fraction is larger for the hyperbolic heat conduction.

  • ICT-driven economic and financial development. Analyses of European countries
    • Ewa Lechman
    • Adam Marszk
    2019

    ICT-Driven Economic and Financial Development: Analyses of European Countries demonstrates the effects of ICT diffusion on economic, social and financial development by examining their impact on the structure and dynamics of national economies. It provides the insight into shifts observed in labour markets, international trade activities productivity factors, education and use of innovative financial products. It combines empirical analyses and data sources stretching back to 1990 make it an important contribution to understanding the effects of ICT diffusion on economic and financial development. The book answers questions such as how will national and regional economies react to upcoming ICT developments and growing usage, and what is the magnitude of impact of new information and communication technologies on various aspects of social and economic life.

  • Identification, Assessment and Automated Classification of Requirements Engineering Techniques
    • Aleksander Jarzębowicz
    • Kacper Sztramski
    2019 Full text

    Selection of suitable techniques to be used in requirements engineering or business analysis activities is not easy, especially considering the large number of new proposals that emerged in recent years. This paper provides a summary of techniques recommended by major sources recognized by the industry. A universal attribute structure for the description of techniques is proposed and used to describe 33 techniques most frequently quoted by reviewed sources. A pilot study of automated classification of techniques based on attribute values is also reported. The study used fuzzy c-means clustering algorithm and produced pairings of complementary techniques, most of which successfully passed validation conducted by business analysis practitioners.

  • Identification of damages in the inlet air duct of a diesel engine based on exhaust gas temperature measurements
    • Patrycja Puzdrowska
    2019 Full text Combustion Engines

    The temperature of the exhaust gas of a diesel piston engine, measured in the characteristic control sections of its thermo-flow system, can be a valuable source of diagnostic information about the technical condition of the elements limiting the working spaces thus separated, including the turbocharging system, but also its fuel supply system and replacement of the medium. In standard marine engine measurement systems equipped with an impulse turbocharging system, the exhaust gas temperature is measured at the outlet of individual cylinders and before and after the turbocharger turbine, using traditional thermocouples with high measurement inertia (time constant of tenths of a second and more). This means that for further diagnostic analyses, the average value of the periodically changing temperature of the exhaust stream leaving individual engine cylinders, the exhaust stream in the collective duct feeding the turbine and the exhaust stream in the exhaust duct of the turbine is used. This article proposes a new approach to the issue of diagnostic informationiveness of the exhaust gas temperature of a diesel engine, extending its observations with the dynamics of changes in the duration of one working cycle. The aim of the tests carried out on the laboratory stand of Farymann Diesel engine type D10 was to determine the diagnostic relations between the loss of permeability of the inlet air channel filter baffle and selected standards of the quick-changing signal of the exhaust gas temperature. On the basis of the calculations carried out, the following dynamic features of the recorded signal were determined: maximum amplitude of instantaneous exhaust gas temperature values (peak-to-peak value), its rate of increase and decrease, and the specific enthalpy of exhaust gases within one engine work cycle. Comparative analysis of numerical data characterizing the recorded quick-changing exhaust gas temperature courses clearly indicates obvious thermodynamic and energy consequences of partial loss of flow capacity of the air channel supplying the combustion chamber of the test engine. A further development of the experimental test programme is foreseen in order to determine a diagnostic matrix to support the diagnostic inference about the technical condition of the diesel engine on the basis of measurements and analysis of the quick-changing exhaust gas temperature.

  • Identification of evolutionary conserved DNA sequence and corresponding S21 ribosomal protein region for diagnostic purposes of all Borrelia spirochetes
    • Roman Kotłowski
    • Lucyna Holec-Gąsior
    2019 Full text Acta Biochimica Polonica

    It is still under investigation, whether all Borrelia sp. causing Lyme borreliosis and other diseases are already identified and properly classified as human pathogens. For this reason, it is of great importance to develop a diagnostic ELISA test that detects all Borrelia sp. The aim of this study was to identify conserved DNA and protein regions present in all currently known Borrelia sp. In experimental studies 31 available Borrelia sp. genomes were aligned and screened for the presence of evolutionary conserved regions. As a result of bioinformatics analysis, one evolutionally conserved DNA region encoding a core fragment of the S21 ribosomal protein was identified. Both a couple of genus-specific PCR primers and the S21 protein B-cell epitope were designed for prospective diagnostic purposes.

  • Identification of Shear Modulus Parameters of Half-space Inhomogeneous by Depth
    • Vladimir Zelentsov
    • Polina Lapina
    • Victor Eremeev
    2019 Full text AIP Conference Proceedings

    The paper propose a method for determining of the parameters of the exponential shear modulus of a functionally graded half-space based on the solution of the problem of a pure shear of an elastic functionally graded half-space by a strip punch. The solution of the integral equation of the contact problem is constructed by asymptotic methods with respect to the dimensionless parameter. The dependence of contact stresses on the parameters of the shear modulus is analyzed. The determination of the parameters of the shear modulus of a functionally graded half-space is based on the values of shear stresses at the contact. By choosing proper shear modulus parameters of the functionally graded half-space, “approximately homogeneous” area inside of the functionally graded half-space are developed.

  • Identifying Selected Tram Transport Risks
    • Marcin Budzyński
    • Agnieszka Tubis
    • Kazimierz Jamroz
    2019 Full text IOP Conference Series: Materials Science and Engineering

    In the area of transport infrastructure risks, infrastructure is inspected for safety. It is an element of transport safety management based on risk management and forms part of preventative activities and measures. As regards tram infrastructure which is a component of urban transport infrastructure, there are potential collisions with cars, cyclists and pedestrians. Data from Gdansk Buses and Trams (GAiT) shows that between 2012 and 2016 on average there were about 650 incidents involving trams (collisions and accidents). The objective of inspection will be to identify sources of hazards which may lead to tram accidents or indirectly when tram infrastructuremay contribute to accidents not involving trams. The objective of the work is to identify the risks to urban public transport operation with a special focus on trams and to formulate recommendations on how to improve its quality and safety