Repozytorium publikacji - Politechnika Gdańska

Ustawienia strony

english
Repozytorium publikacji
Politechniki Gdańskiej

Pokaż publikacje z roku

Ostatnie pozycje

  • Simultaneous voltammetric determination of Cd2+, Pb2+, and Cu2+ ions captured by Fe3O4@SiO2 core-shell nanostructures of various outer amino chain length
    • Amanda Kulpa
    • Jacek Ryl
    • Grzegorz Schroeder
    • Adrian Koterwa
    • Jacek Sein Anand
    • Tadeusz Ossowski
    • Paweł Niedziałkowski
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    In the present study, we examined a novel functionalised magnetic nanoparticles Fe3O4@SiO2-Nn as a nano adsorbent for binding of Cd2+, Pb2+, Cu2+ ions in an aqueous solution. First, we obtained the nanoparticles functionalised with various carbon chains containing different number of amino groups: (3-amino)propyltriethoxysilane (Fe3O4@SiO2-N1), N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (Fe3O4@SiO2-N2) and N1-(3-trimethoxysilylpropyl)diethylenetriamine (Fe3O4@SiO2-N3). In the next step, we conducted their characterisation using SEM, TEM, FT-IR, and XPS methods. The detection of Cd2+, Pb2+, Cu2+ metal ions was performed under optimised experimental conditions using DPASV and HDME techniques. Using these methods we conducted the Cd2+, Pb2+, Cu2+ binding comparison in 4.5 μM concentration with 4 mg of Fe3O4@SiO2-Nn. Obtained results show that the adsorption rate of each ion differs due to the nanoparticles modification. The highest Pb2+ binding capacity was achieved using Fe3O4@SiO2-N1 and Fe3O4@SiO2-N2. The smallest binding capacity was observed for Cd2+ ions by Fe3O4@SiO2-N2 and Fe3O4@SiO2-N1. The Cd2+ biding was not observed for both Fe3O4@SiO2-N2 and Fe3O4@SiO2-N3 nanoparticles. Additionally, Pb2+ was not bound by Fe3O4@SiO2-N3. The research results show that the Fe3O4@SiO2-N3 nanoparticles bind copper ions with high selectivity. For the first time we performed the adsorption-desorption experiments using DPASV to prove the Cu2+ binding activity of Fe3O4@SiO2-N3 nanoparticles. Obtained results indicate that examined nanoparticles show strong binding capability. Additionally, we obtained 99.9% recovery of Cu2+ ions.

  • Single and Three -Phase PWM AC/AC Converters as Semiconductor Transformers
    • Ryszard Strzelecki
    • Natalia Strzelecka
    2020 Pełny tekst

    AC voltage transformation circuits contain pure or reactance PWM AC/AC converters. These circuits can be treated as AC/AC semiconductor transformers. This paper reviews single-phase and three-phase topologies: both non-isolated and isolated, single as well as two quadrant structure. Additionally, this paper present selected examples of their applications.

  • Single crystal growth and physical properties of MCo2Al9 (M= Sr, Ba)
    • Zuzanna Ryżyńska
    • Tomasz Klimczuk
    • Michał Winiarski
    2020 Pełny tekst JOURNAL OF SOLID STATE CHEMISTRY

    Single crystals of SrCo2Al and BaCo2Al9 were grown using a self-flux method. A LeBail analysis of the powder X-ray diffraction patterns show that both compounds crystallize in a hexagonal (P6/mmm) crystal structure with lattice parameters: a ​= ​7.8995(1) Å, c ​= ​3.9159(1) Å for SrCo2Al9, and a ​= ​7.9162(2) Å, c ​= ​3.9702(1) Å for BaCo2Al9 aluminide. The low temperature analysis of the heat capacity measurements give a Sommerfeld coefficient γ ​= ​4.99(6) mJ mol−1 K−2 for SrCo2Al9 and almost twice larger γ ​= ​7.94(9) mJ mol−1 K−2 for BaCo2Al9. Resistivity measurements show metallic-like behavior, with reasonably large residual resistivity ratio RRR ​= ​6 and 10 for SrCo2Al9 and BaCo2Al9, respectively. Neither heat capacity nor resistivity measurements reveal any phase transition down to 1.8 ​K.

  • Single-step grown boron doped nanocrystalline diamond-carbon nanograss hybrid as an efficient supercapacitor electrode
    • Debosmita Banerjee
    • Kamatchi J Sankaran
    • Sujit Deshmukh
    • Mateusz Ficek
    • Chien-Jui Yeh
    • Jacek Ryl
    • I-Nan Lin
    • Robert Bogdanowicz
    • Aloke Kanjilal
    • Ken Haenen
    • Susanta Sinha Roy
    2020 NANOSCALE

    Direct synthesis of nano-structured carbon hybrid consisting of vertically aligned carbon nanograss on top of boron-doped nanocrystalline diamond is demonstrated and the carbon hybrid is further applied as an electrode material for the fabrication of supercapacitor. The hybrid film combines the dual advantages of sp2 (carbon nanograss) and sp3 (nanocrystalline diamond) bonded carbon, possessing not only the excellent electrical characteristics of sp2 carbon but also exceptional electrochemical stability of sp3 carbon. As a result, the specific capacitance of the as-prepared hybrid material reaches upto 0.4 F cm-2, one of the highest reported in diamond-based supercapacitors. The entire electrochemical results exhibit enhanced electron transfer efficiency with remarkable stability of 95% of capacitance retention even after 10000 cycles.

  • Skład chemiczny wód podziemnych dopływających z Pobrzeża Kaszubskiego do Zatoki Puckiej
    • Dawid Potrykus
    • Małgorzata Pruszkowska-Caceres
    • Beata Jaworska-Szulc
    • Anna Gumuła-Kawęcka
    • Adam Szymkiewicz
    2020 Pełny tekst Przegląd Geologiczny

    Zatoka Pucka jest płytkim akwenem morskim szczególnie wrażliwym na dopływ biogenów z otaczających obszarów lądowych. Postępujący problem eutrofizacji wód zatoki wymaga podjęcia działań badawczych i naprawczych, w tym również odpowiedzi na pytanie czy i w jaki sposób spływające do zatoki wody podziemne wpływają na zjawisko eutrofizacji. Celem przeprowadzonych badań, przedstawionych w niniejszym artykule, było określenie składu chemicznego wód podziemnych wraz z analizą ich jakości na wysoczyznowym obszarze Pobrzeża Kaszubskiego. Analizując wyniki badań można uznać, iż skład chemiczny wydzielonych poziomów wodonośnych jest zbliżony. Wykazuje jednak zmienność parametrów hydrogeochemicznych w czasie, zmienność wraz ze wzrostem głębokości występowania wód podziemnych oraz mozaikowy rozkład przestrzenny. Zanieczyszczenie wód podziemnych dotyczy przede wszystkim wód poziomu zawieszonego Qz oraz górnego poziomu wodonośnego Q1, i występuje jedynie punktowo. Zatoka Pucka jest obszarem drenażu wód podziemnych poziomów Q1 i Q2. Stwierdzono, że w wodach podziemnych dopływających do zatoki stężenia większości analizowanych parametrów hydrogeochemicznych nie przekraczają norm jakościowych dla I i II klasy (wody bardzo dobrej i dobrej jakości).

  • Skośna kryza segmentowa do pomiaru przepływającego strumienia płynu
    • Andrzej Mrowiec
    • Marcin Heronimczak
    • Anna Golijanek-Jędrzejczyk
    2020

    Przedstawiono prototypową skośną kryzę segmentową, którą cechuje to, że w zwężkowym układzie pomiaru strumienia objętości wykorzystano pochyloną płaszczyznę kryzy segmentowej. Płyn napierając na kryzę spływa po jej powierzchni. Przyjęto kąt napływu α między płaszczyzną kryzy segmentowej a kierunkiem przepływu (osią rurociągu) mniejszy od kąta prostego. Wyniki symulacji numerycznych oraz badań przepływowych przez zwężkowy przepływomierz ze skośną kryzą segmentową, przy jej pochyleniu α = 60° i przewężeniu β = 0,5, przedstawiono w postaci wykresów i map rozkładu ciśnienia statycznego.

  • Skuteczność nowoczesnych algorytmów optymalizacji czerpiących inspirację z procesów naturalnych
    • Zuzanna Klawikowska
    • Bartosz Puchalski
    2020 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

    Ze względu na nieistnienie uniwersalnego algorytmu optymalizacji rozwiązującego wszystkie problemy naukowo techniczne opracowywanie nowych i wydajniejszych obliczeniowo algorytmów optymalizacyjnych wciąż jest popularnym zadaniem. Przeglądając literaturę z dziedziny optymalizacji można zauważyć trend tworzenia „wymyślnych” algorytmów opartych na procesach naturalnych. W artykule sprawdzono skuteczność nowo powstałych algorytmów meta-heurystycznych zainspirowanych życiem owadów i zwierząt – czarnych wdów (algorytm BWO) oraz szarego wilka (algorytm GWO). Skuteczność działania wybranych algorytmów porównano z klasycznym algorytmem quasi Newtonowskim BFGS oraz strategią ewolucyjną CMA-ES, które charakteryzują się solidnym uwarunkowaniem matematycznym. W celach porównawczych wykorzystano 3 wybrane funkcje testowe. W ramach badań sprawdzono również wpływ liczby zmiennych decyzyjnych na czas uzyskiwania rozwiązania.

  • Slurry Surfacing Mixes on the Basis of Bitumen Modified with Phenol-Cresol-Formaldehyde Resin
    • Yuriy Demchuk
    • Volodymyr Gunka
    • Serhiy Pyshyev
    • Iurii Sidun
    • Yurii Hrynchuk
    • Justyna Kucińska-Lipka
    • Michael Bratychak
    2020 Pełny tekst Chemistry & Chemical Technology

    Slow-breaking monophase cationic bitumen emulsions have been produced on the basis of bitumen modified with phenol-cresol-formaldehyde resin (PhCR-F). Bitumen emulsions were used as a binder for thin-layer coatings with slurry surfacing mixes (SSM). Physical and technical parameters of modified and unmodified emulsions were determined and analyzed. The optimal compositions of SSM were selected according to the breaking criterion. The values of SSM wet track abrasion were determined. It was found that the addition of PhCR-F allows to improve the adhesion properties of the thin-layer coatings.

  • Small Vessel with Inboard Engine Retrofitting Concepts; Real Boat Tests, Laboratory Hybrid Drive Tests and Theoretical Studies
    • Wojciech Leśniewski
    • Daniel Piątek
    • Konrad Marszałkowski
    • Wojciech Litwin
    2020 Pełny tekst ENERGIES

    The development of modern technologies and their increasing availability, as well as the falling costs of highly ecient propulsion systems and power sources, have resulted in electric or hybrid propulsions systems’ growing popularity for use on watercraft. Presented in the paper are design and lab tests of a prototype parallel hybrid propulsion system. It describes a concept of retrofitting a conventionally powered nine meter-long vessel with the system, and includes results of power and eciency measurements, as well as calculations of the vessel’s operating range under the propulsion of its electric motor. The concept of adding of a solar panels array was studied.

  • Smart acoustic band structures
    • Wiktor Waszkowiak
    • Arkadiusz Żak
    • Magdalena Palacz
    • Marek Krawczuk
    2020

    Smart acoustic band structures exhibit very interesting and non-standard physical properties due to the periodic nature of their certain characteristic on different scale levels. They manifest mostly in their frequency spectra as socalled frequency band-gaps or stop-bands, what has a great impact on the behaviour of these structures in relation to the propagation of vibro-acoustic signals that can be transmitted through the structures in some precisely defined frequency bands. Properties of acoustic band structures are directly linked to their geometry on the level of the unit cell, which parameters determine structural dynamics of such structures on the macroscopic scale. Here the piezoelectric transducers play a significant role. The combined exploitation of active properties of acoustic band structures equipped with active piezoelectric elements, in order to filter or damp transmitted vibro-acoustic signals, allows for very effective their applications. In their paper, the authors present certain results of certain computer simulations by the time-domain spectral finite element method, related to 1-D smart active and passive acoustic band structures supplemented with experimental measurements.

  • Smart Decisional DNA Technology to Enhance Industry 4.0 Environment in Conjunction with Conventional Manufacturing
    • Imran Shafiq
    • Cesar Sanin
    • Edward Szczerbicki
    2020

    Knowledge-based support has become an indispensable part not only to the traditional manufacturing set-ups but also to the new fast-emerging Industry 4.0 scenario. In this regard, successful research has been performed and extensively reported to develop Decisional DNA based knowledge representation models of engineering object and engineering process called Virtual engineering object (VEO), Virtual engineering process (VEP) and Virtual engineering factory (VEF). These models are the virtual representation of manufacturing resources, and with the help of IoT, are capable of capturing the past experience and formal decisions. In this chapter, a complete virtual manufacturing environment is summarized. Furthermore, the scope of this work is explained in the Cyber-Physical Systems (CPS) based Industry 4.0 framework. Four case studies are presented to validate the practical implementation of the proposed concept. In the first case the idea of VEO-VEP-VEF is applied to design an intelligent factory framework to achieve contextual information through real-time visualization. In the second study, the smart tool performance analysis is presented in which data of key tool parameters like tool life, surface integrity, tool forces, and chip formation can be sensed in real-time; also predictions can be made according to the specific requirements. In the third case study, the technique of Decisional DNA (DDNA) is applied to FMS to develop a generic model to achieve effective scheduling and manufacturing flexibility. In the last study, the framework to manage the storage, analysis, and processing of data, information, and knowledge of a typical CIM is presented. The benefits of this approach are manifold as it creates manufacturing DNA of a factory, felicitates in effective decision making, increases the rate of production, reduces errors and production waste, and streamlines manufacturing sub-systems. Moreover, and can be instrumental in designing Industry 4.0.

  • Smart Embedded Systems with Decisional DNA Knowledge Representation
    • Zhang Haoxi
    • Fei Li
    • Cesar Sanin
    • Edward Szczerbicki
    2020

    Embedded systems have been in use since the 1970s. For most of their history embedded systems were seen simply as small computers designed to accomplish one or a few dedicated functions; and they were usually working under limited resources i.e. limited computing power, limited memories, and limited energy sources. As such, embedded systems have not drawn much attention from researchers, especially from those in the artificial intelligence area. Thanks to the efforts of scientists over recent years, great progress has been made in both computer hardware and software, which enables us to have much more powerful computers in very small sizes and with many more functions. Consequently, new expectations and needs for embedded systems have increased considerably. Today, smart embedded systems are expected, which are supposed to have capability to learn from past task executions and evolve their performance based on learnt knowledge, and assist users to make good decisions more efficiently. Therefore, how to make embedded systems smart is becoming one of the researchers’ new challenges. In this chapter, we introduce the Experience-Oriented Smart Embedded Systems (EOSES) that is proposed as a new technological scheme providing embedded systems with capabilities for experiential knowledge capturing, storage, reuse, evolving, and sharing. In this scheme, knowledge is represented as the Set of Experience Knowledge Structure (SOEKS or shortly SOE) and organized as Decisional DNA. The scheme is mainly based on conceptual principles from embedded systems and knowledge management. The objective behind this research is to offer large-scale support for intelligent, autonomous, and coordinated knowledge management on various embedded systems. Several conceptual elements of this research have been implemented in testing prototypes, and the experimental results show that the EOSES scheme can not only provide active knowledge management to different embedded systems, it can also enable various systems to learn from their daily operations in many different fields to acquire valuable knowledge, assist decision making, reduce human workers’ workload, and improve the system’s performance. As a result, the EOSES has great potential for meeting today’s demands for embedded systems, and providing a universe knowledge management scheme for mass autonomous mechanisms.

  • Smart Innovation Engineering Using Set of Experience and Decisional DNA
    • Mohammad Waris
    • Cesar Sanin
    • Edward Szczerbicki
    2020

    Knowledge-based Engineering Systems are founded upon integration of knowledge into computer systems and are one of the core requirements for the future Industry 4.0. Since the fourth industrial revolution is passing through the developing phase, implementation of Cyber-Physical Production Systems require more realistic approach. Knowledge Management and Knowledge Engineering plays an important role in manufacturing industries facing global competition. One of the most promising areas where Knowledge Management is studied and applied is product innovation. This chapter presents the idea of Smart Innovation Engineering (SIE) System based on Set of Experience and Decisional DNA that facilitates the process of product innovation. It collects the experiential knowledge from the formal decisional event from the group of similar products having some common functions and features. The SIE system behaves like a group of experts in its domain as it collects, captures and stores the experiential knowledge and reuses this experiential knowledge as well that ultimately enhances the innovation process. The analysis of basic concepts and implementation method proves that SIE system is an advanced form of Cyber Physical Systems. It is flexible, systematic, fast, and supports customization. It can play a vital role towards Industry 4.0 development.

  • Smart Services for Improving eCommerce
    • Andrzej Sobecki
    • Julian Szymański
    • Henryk Krawczyk
    • Higinio Mora-Mora
    • David Gil
    2020

    The level of customer support provided by the existing eCom-merce solutions assumes that the person using the functionality of theshop has sufficient knowledge to decide on the purchase transaction. Alow conversion rate indicates that customers are more likely to seekknowledge about the particular product than finalize the transaction.This is facilitated by the continuous development of customers’ digi-tal competencies, resulting in the increasing popularity of web servicesenabling the exchange of information, e.g. through social networks. Cur-rently the user act with eCommerce platform like a source of informa-tion. At the same time, he or she usually use more than one source ofinformation e.g., web portals, social networks, etc. The existing onlineshops seem unsuited to these trends because they remain simple tradingplatforms without integration with external web services and sources ofknowledge. New categories of smart services are suggested, enabling thenewly implemented eCommerce network platform to enhance the offeredknowledge and reduce the abandonment of the platform by the user. Ourempirical studies show an increase in the conversion rate in the case ofshops which increased the level of customer support using the proposedmodel of integration.

  • SMART SHOP SERVICES FOR BUILDING CUSTOMER-ORIENTED SCENARIOS
    • Henryk Krawczyk
    • Andrzej Sobecki
    2020 Pełny tekst TASK Quarterly

    The shops of today mostly support the customer by offering him or her products based on basic relationships between products viewed or ordered by users with similar tastes. This common approach may fail in many cases especially when the user does not have sufficient knowledge about the market, or when he or she wants to build a set of products in more than one shop. New categories of smart shop services are proposed in order to execute such customer-oriented scenarios where recommended products do meet mutual dependencies with products previously ordered by the customer. An attempt is made to collect additional information about the behavior of users (from past and current contexts) and represent it in a targeted graph called the customer-oriented scenario. Four types of such scenarios are distinguished depending on how many shops have been visited by the user before buying the expected products and how many products the user wants to buy. Moreover, the proposed scenario model provides the possibility of showing which services had been used by the user before the selection was made. Customer-oriented scenarios may be created post factum based on event data logs or before the user will use the shop, which means that it can be arranged which information, knowledge sources (internal or external), products or categories should be suggested in some context of the user’s decision. The possibility of leveraging additional smart services into a traditional trading platform may help users, especially when they want to implement a complex scenario and order many products with mutual dependencies or in a situation when the user wants to understand the market before buying something. Using internal and external services allows creating a network for distributing knowledge focused on the actual customer context in a shop.

  • Smart Virtual Product Development (SVPD): Experience Based Product Development System for Industry 4.0
    • Muhammad Bilal
    • Cesar Sanin
    • Edward Szczerbicki
    2020

    This chapter presents the concept of smart virtual product development (SVPD) system capable of supporting industrial product development. It enhances the decision making process during various activities involved in product development i.e. product design, manufacturing, and inspection planning. This is achieved by using the explicit knowledge of past formal decision events, which are captured, stored, and recalled in the form of set of experiences (SOEs). The basic description and principles of approach are introduced first, and then the prototype version of the system is developed and tested. Working of the design knowledge management module and manufacturing capability analysis and process planning module of the system are demonstrated with the case study, which verifies the feasibility of the proposed approach. The presented system successfully supports smart product design and manufacturing, and it can play a vital role in Industry 4.0.

  • Smart Virtual Product Development (SVPD) System to Support Product Inspection Planning in Industry 4.0
    • Muhammad Ahmed
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Pełny tekst Procedia Computer Science

    This paper presents the idea of supporting product inspection planning process during the early stages of product life cycle for the experts working on product development. Aim of this research is to assist a collaborative product development process by using Smart Virtual Product Development (SVPD) system, which is based on Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). The proposed system is developed to support three key aspects of industrial product development i.e. design, manufacturing, and product inspection. Therefore, it comprises of three main modules; design knowledge management (DKM), manufacturing capability and process planning (MCAPP), and product inspection planning (PIP). It collects, stores, and uses experiential knowledge from formal decisional events in the form of set of experience (SOE). This research enlightens the working mechanism of the PIP module, and shows how experiential knowledge related to product inspection can be used during the early stages of product development process. This experiential knowledge is extracted and stored from similar products having some common features and functions. First, the basic description and principles of the approach are introduced, then the prototype version of the system is developed and tested for product inspection planning (PIP) module for the case study, which verifies the feasibility of the proposed approach. The presented system successfully supports smart manufacturing and can play a vital role in Industry 4.0.

  • Social benefits valuation of hosting non-mega sporting events
    • Krystian Zawadzki
    2020 Pełny tekst International Journal of Event and Festival Management

    Purpose In the study, an attempt was made to estimate the social benefits resulting from three non-mega sporting events organized in Ergo Arena located on the border of two cities in Poland. By attributing a value to intangible social benefits, the intangible effect was determined and compared to the expenditure incurred in the construction of Ergo Arena Hall. Design/methodology/approach In order to value social intangible effects of three non-mega sporting events the Contingent Valuation Method was applied. Each time, the Contingent Valuation Method study covered the area of the two cities: Gdańsk and Sopot and was conducted on a sample of 500 people – 250 per city. The mean values of Willingness-to-Pay were used in order to obtain aggregate values of intangible benefits. Finally, the aggregate results were compared to expenditure incurred in connection with the construction of Ergo Arena Hall. Findings It appeared that intangible effects were eagerly valued by the residents of Gdańsk and Sopot. The aggregated value of all three sporting events was estimated at PLN 8.8 million. The obtained results question the equal share of both cities in financing but confirm that under certain circumstances, hosting non-mega sporting events may justify the use of public funds. In the case of the two cities, the reasonable reason for the employment of public means is the size of Gdańsk compared to Sopot. Originality/value The paper fulfils the research gap which arises regarding Willingness-to-Pay in estimating the intangible social effects of non-mega sporting events and considering these effects in the net effect valuation. The findings have implications for policy makers since they show to what extent it may be justified to use public means in order to host non-mega sporting events.

  • Soft Sensor Application in Identification of the Activated Sludge Bulking Considering the Technological and Economical Aspects of Smart Systems Functioning
    • Bartosz Szeląg
    • Jakub Drewnowski
    • Grzegorz Łagód
    • Dariusz Majerek
    • Ewa Dacewicz
    • Francesco Fatone
    2020 Pełny tekst SENSORS

    The paper presented the methodology for the construction of a soft sensor used for activated sludge bulking identification. Devising such solutions fits within the current trends and development of a smart system and infrastructure within smart cities. In order to optimize the selection of the data-mining method depending on the data collected within a wastewater treatment plant (WWTP), a number of methods were considered, including: artificial neural networks, support vector machines, random forests, boosted trees, and logistic regression. The analysis conducted sought the combinations of independent variables for which the devised soft sensor is characterized with high accuracy and at a relatively low cost of determination. With the measurement results pertaining to the quantity and quality of wastewater as well as the temperature in the activated sludge chambers, a good fit can be achieved with the boosted trees method. In order to simplify the selection of an optimal method for the identification of activated sludge bulking depending on the model requirements and the data collected within the WWTP, an original system of weight estimation was proposed, enabling a reduction in the number of independent variables in a model— quantity and quality of wastewater, operational parameters, and the cost of conducting measurements.

  • Soft-mode enhanced type-I superconductivity in LiPd2Ge
    • Karolina Górnicka
    • Gabriel Kuderowicz
    • Elizabeth M. Carnicom
    • Kamil Kutorasiński
    • Bartlomiej Wiendlocha
    • Robert J. Cava
    • Tomasz Klimczuk
    2020 Pełny tekst PHYSICAL REVIEW B

    The synthesis, crystal structure, and physical properties (magnetization, resistivity, heat capacity) in combination with theoretical calculations of the electronic structure and phonon properties are reported for intermetallic compounds LiPd2X (X = Si, Ge, and Sn). LeBail refinement of powder x-ray diffraction data confirms that all compounds belong to the Heusler family (space group Fm-3m, No. 225). The lattice parameter increases with atomic size of X, and its value varies from a = 5.9059(4) Å for LiPd2Si and a = 6.0082(3) Å for LiPd2Ge, to a = 6.2644(1) Å for LiPd2Sn. The first compound, LiPd2Si, has apparently not been previously reported. All measured quantities demonstrate that LiPd2Ge exhibits superconductivity below Tc = 1.96 K and the normal and superconducting-state data indicate that it is a weak-strength type-I superconductor (C/γ Tc = 1.38) with electron-phonon coupling constant λe−p = (0.53 − 0.56). LiPd2Si and LiPd2Sn are not superconducting above 1.68 K. The experimental observations are supported by theoretical calculations which show that LiPd2Ge has the highest computed λe−p and Tc of the group. A strong softening of the acoustic phonon mode is calculated, and in the case of X = Ge and Sn, imaginary phonon frequencies were computed. The soft mode is most pronounced in the case of LiPd2Ge, which suggests its correlation with superconductivity.

  • Solvent dependency of carbon dioxide Henry's constant in aqueous solutions of choline chloride-ethylene glycol based deep eutectic solvent
    • Ali Reza Harifi-Mood
    • Fereshteh Mohammadpour
    • Grzegorz Boczkaj
    2020 Pełny tekst JOURNAL OF MOLECULAR LIQUIDS

    The Henry's constants of carbon dioxide absorbed in aqueous solutions of ethaline (choline chloride-ethylene glycol) were determined for temperatures ranging from 303.15 to 323.15 K based on solubility measurement at CO2 pressure ranging from 0 to 6 bar (0.6 MPa). These studies revealed that the Henry's constant increased with the increase of temperature. Data indicated the highest capacity of CO2 absorption is obtained for ethaline and the lowest temperature dependency of absorption capacity is reported for aqueous solution of ethaline based deep eutectic solvent (0.3 mol fraction of water). The dependence of Henry's constant on solvent composition and solvent properties was investigated using preferential solvation model and linear free energy relationship method. Results showed that CO2 was preferentially solvated by ethaline in aqueous solution. Furthermore it revealed that solute-solvent interactions related to the scale of hydrogen bond donor ability of the solvent were the main parameter which controls the solubility of CO2 in the studied system. Presented methodology is useful for selection of best absorbent composition for systems of hot off-gases treatment. Interesting and practical results obtained in this work, indicated that precisely selected composition of the deep eutectic solvent based absorbent provide low sensitivity of the treatment performance in respect to the temperature of the treated gas.

  • Solvent Impact on the Diversity of Products in the Reaction of Lithium Diphenylphosphide and a Ti(III) Complex Supported by a tBu2P–P(SiMe3) Ligand
    • Aleksandra Ziółkowska
    • Natalia Szynkiewicz
    • Jerzy Pikies
    • Łukasz Ponikiewski
    2020 Pełny tekst INORGANIC CHEMISTRY

    We present two important trends in the reactivity ofthe titanium complex [MeNacNacTi(Cl){η2-P(SiMe3)-PtBu2}](MeNacNac− = [Ar]NC(Me)CHC(Me)N[Ar]; Ar = 2,6-iPr2Ph)with nucleophilic reagents RLi (R = Ph2P,tBuO, (Me3Si)2N, andtBu2N) depending on the reaction medium. Reaction in nonpolarsolvent (toluene) leads to three main products: via an autoredoxprocess and nucleophilic substitution at the Ti-atom to afford theTi(IV) complex [MeNacNacTi(R){η2-P-PtBu2}] (1for R = PPh2),via the elimination of Me3SiR to afford Ti(III) complex[MeNacNacTi(Cl){η2-P-PtBu2}]−[Li(12-crown-4)2]+(2), and via2e−reduction process to afford new ionic complex [{ArNC(Me)-CHC(Me)}TiNAr{η1-P(SiMe3)-PtBu2}]−[Li(12-crown-4)2]+(3). Quite differently, the complex [MeNacNacTi(Cl){η2-P(SiMe3)-PtBu2}] reacts with Ph2PLi in THF, unexpectedly yielding two new, four-coordinate Ti(IV) imido complexes4a[{ArNC(Me)CHC(H)(Me)-P(PtBu2)}TiNAr(Cl)]−[Li(12-crown-4)2]+·(toluene)2and4b[{ArNC(CH2)CHC(Me)-P(PtBu2)}TiNAr-(Cl)]−[Li(12-crown-4)2]+·(Et2O). Complex2dissolved in THF converts to4aand4b.1,2,3,4a, and4bwere characterized by X-ray diffraction.1,4a, and4bwere also fully characterized by multinuclear NMR spectroscopy.

  • Some Security Features of Selected IoT Platforms
    • Robert Kałaska
    • Paweł Czarnul
    2020 Pełny tekst TASK Quarterly

    IoT (Internet of Things) is certainly one of the leading current and future trends for processing in the current distributed world. It is changing our life and society. IoT allows new ubiquitous applications and processing, but, on the other hand, it introduces potentially serious security threats. Nowadays researchers in IoT areas should, without a doubt, consider and focus on security aspects. This paper is aimed at a high-level review of the existing IoT enabling standalone middleware solutions and frameworks in terms of potential application areas, architecture and components, communication APIs as well as support for key security features including access control, support against attacks on service, device authorization and data filtering. On the one hand, it allows the developer to choose the middleware best matching their needs. On the other hand, it can serve as a starting point for further research on middleware security features based on the provid ed security related open areas and challenges.

  • Sophistication assessment of existing FEM models of orbital blowout trauma: Is models valuation justified?
    • Marcin Zmuda Trzebiatowski
    • Andrzej Skorek
    2020 Journal of Stomatology Oral and Maxillofacial Surgery

    After a thorough study of the work entitled “Development and validation of an optimized finite element model of the human orbit”, some doubts aroused concerning the sophistication assessment of the existing finite element method (FEM) models of orbital blow-out. Although the work was unquestionably innovative, and the results were not only fascinating but also invaluable, the authors stated that their model was the most sophisticated one ever developed to their best knowledge. Hence, the purpose of this letter is to consider whether and upon what circumstances FEM models valuation may be justified.

  • Spatial and vertical distribution analysis of heavy metals in urban retention tanks sediments: a case study of Strzyza Stream
    • Nicole Nawrot
    • Ewa Wojciechowska
    • Karolina Matej-Łukowicz
    • Jolanta Walkusz-miotk
    • Ksenia Pazdro
    2020 Pełny tekst ENVIRONMENTAL GEOCHEMISTRY AND HEALTH

    Concentrations of seven heavy metals (HMs): Zn, Cu, Pb, Cd, Ni, Cr, and Fe in core samples of bottom sediments from four retention tanks (RTs) located along the Strzyza Stream in northern Poland (Gdansk) were measured to obtain a general view of sediment quality. The recognition of contamination and potential environmental impacts is the main aim of this paper. A total of 96 sediment samples were collected from eight sampling sites at depths of 0–2 cm, 8–10 cm, 16–18 cm, 24–26 cm. Concentrations of Cu, Zn, Pb, Fe, Ni, and Cr were measured with AAS while Cd concentration was measured with ICP-MS. Granulometric analyses with normalized sieve apertures were carried out. Geochemical indices: enrichment factor, anthropogenic factor, and modified degree of contamination (mCd) were used to assess the contamination level. Concentrations of HMs in sediments changed in the range: Cu (3.24–119 mg/kg d.w.), Zn (12.5–584 mg/kg d.w.), Pb (4.91–309 mg/kg d.w.), Cd (0.003–0.716 mg/kg d.w.), Ni (1.57–25.8 mg/kg d.w.), Cr (2.45–74.5 mg/kg d.w.), and Fe (3993–63817 mg/kg d.w.). The sequential extraction verified the bonding of HMs with non-mobile fractions. Geochemical indices showed widespread pollution by Cu, Pb, Cd, and Zn. Cluster and factor analysis distinguished three related subgroups of HMs: Pb, Ni–Cr, and Fe–Cd–Cu–Zn, suggesting possible common source of each subgroup. Strongly contaminated sediments were distinguished in sediment cores in two middle stream RTs characterized by intense urbanization in their direct catchments.

  • Spatial Differences in the Chemical Composition of Surface Water in the Hornsund Fjord Area: A Statistical Analysis with A Focus on Local Pollution Sources
    • Krystyna Kozioł
    • Ruman Marek
    • Filip Pawlak
    • Stanisław Chmiel
    • Żaneta Polkowska
    2020 Pełny tekst Water

    Surface catchments in Svalbard are sensitive to external pollution, and yet what is frequently considered external contamination may originate from local sources and natural processes. In this work, we analyze the chemical composition of surface waters in the catchments surrounding the Polish Polar Station in Svalbard, Hornsund fjord area. We have pooled unpublished and already published data describing surface water composition in 2010, related to its pH, electrical conductivity (EC), metals and metalloids, total organic carbon (TOC) and selected organic compound concentrations, including persistent organic pollutants (POPs) and surfactants. These data were statistically analyzed for spatial differences, using Kruskal–Wallis ANOVA and principal component analysis (PCA), with distance from the station in the PCA approximating local human activity impact. The geological composition of the substratum was found to be a strong determinant of metal and metalloid concentrations, sufficient to explain significant differences between the studied water bodies, except for the concentration of Cr. The past and present human activity in the area may have contributed also to some of the polycyclic aromatic hydrocarbons (PAHs), although only in the case of naphthalene can such an effect be confirmed by an inverse correlation with distance from the station. Other likely factors contributing to the chemical concentrations in the local waters are marine influence, long-range pollution transport and release from past deposition in the environment.

  • Special Issue: “Non-Destructive Testing of Structures”
    • Magdalena Rucka
    2020 Pełny tekst Materials

    The Special Issue “Non-Destructive Testing of Structures” has been proposed to present recent developments in the field of diagnostics of structural materials and components in civil and mechanical engineering. The papers highlighted in this editorial concern various aspects of non-invasive diagnostics, including such topics as condition assessments of civil and mechanical structures and connections of structural elements, the inspection of cultural heritage monuments, the testing of structural materials, structural health monitoring systems, the integration of non-destructive testing methods, advanced signal processing for the non-destructive testing of structures (NDT), damage detection and damage imaging, as well as modeling and numerical analyses for supporting structural health monitoring (SHM) systems.

  • Special Issue: Recent Advances in Corrosion Science
    • Jacek Ryl
    2020 Pełny tekst Materials

    The dynamic development of the global industry and growing demand for new material technologies generates constantly increasing problems regarding premature material degradation and the requirement to determine corrosion mechanisms and to develop new protection/evaluation approaches. This Special Issue, “Recent Advances in Corrosion Science”, brings together fourteen articles and one review, providing a snapshot of the recent activity and development in this field.

  • Speciation of heavy metals in bottom sediments of drinking water reservoir for Gdansk, Poland – changes over the 14 years
    • Eliza Kulbat
    • Aleksandra Sokołowska
    2020 Desalination and Water Treatment

    There was conducted a comparative study of the concentrations of heavy metals (Zn, Cu, Pb, and Cd) in the surface layer of sediments collected in two investigation periods: 1999–2000 and 2013. Theresults demonstrated that the degree of metals pollution decreased over time. The contamina-tion factors (Cf) calculated for Zn, Cu, Pb, and Cd were respectively 3.63, 3.86, 3.23, and 3.25 in the first period of research and 1.35, 3.42, 1.98, and 1.43 in the second one. The metal speciation analysis indicated that Zn was mainly associated with the Fe–Mn oxides fraction and the residual fraction, and Cu – with the residual fraction and the organic fraction in both periods of investigation, while the percentage of geochemical fractions in binding of Pb and Cd changed in time. The share of fractions Fe–Mn oxides/carbonate increased in the case of Pb, and carbonate/exchangeable fractions in the case of Cd. The risk assessment code (RAC) decreased in the following order: Cd>Zn>Pb>Cu and was higher in 2013 - it achieved the very high-risk category in the case of Cd. Thus, despite the decrease of sediment pollution, RAC for Cd increased due to changed geochemical speciation.

  • Spectroscopic Optical Coherence Tomography for Thin Layer and Foil Measurements
    • Aleksandra Kamińska
    • Marcin Strąkowski
    • Jerzy Pluciński
    2020 Pełny tekst SENSORS

    The main goal of this research was to assess if it is possible to evaluate the thickness of thin layers (both thin films on the surface and thin layers below the surface of the tested object) and foils using optical coherence tomography (OCT) for thickness assessment under the resolution of the standard commercially available OCT measurement system. In the proposed solution, light backscattered from the evaluated thin layer has been expressed as a multiple beam interference. Therefore, the OCT system was modeled as a two-beam interferometer (e.g., Michelson), in which one beam propagates from the reference arm and the other comes from a Fabry–Pérot interferometer. As a consequence, the mathematical model consists of the main Michelson interferometer, in which the measuring arm represents the Fabry–Pérot interferometer. The parameters of the layer (or foil) are evaluated by analyzing the minimum value of the interference contrast. The model developed predicts the behavior of the thin layers made from different materials (with different refractive indexes) with different thickness and located at different depths. To verify the correctness of the proposed model, an experiment with a wedge cell has been carried out. The wedge cell was shifted across the scanning beam using a linear translation stage with a micrometer screw under the scanning head. The relationship between the thickness of the gap of the wedge cell and the OCT output signal is presented. For the additional verification of the proposed model, the results of the measurements of the thickness of the thin foil were compared with the theoretical results of the simulations. The film thickness was evaluated based on the calculated positions of the minimum value of interference contrast. A combination of the standard potentialities of OCT with the proposed approach to analyzing the signal produces new metrological possibilities. The method developed allows us to evaluate thickness under the resolution of the system and the location of the layer as well. This produces the possibility of measuring a layer which is covered by another layer. Moreover, it is possible to create a thickness map with high sensitivity to thickness changes. These experiments and simulations are the culmination of preliminary research for evaluating the potential of the proposed measurement method.

  • Spectroscopic studies of Nb-doped tricalcium phosphate glass-ceramics prepared by sol-gel method
    • Wojciech Korzeniewski
    • Agnieszka Witkowska
    • Maciej Manecki
    2020 Synchrotron Radiation in Natural Science

    Calcium-phosphate based glasses and glass-ceramics play a crucial role in the tissue engineering development. Apart from their high biocompatibility and excellent ability to undergo varying degrees of resorbability1, they exhibit relatively high bioactivity and due to that they are commonly used as bone and dental implants. A substantial research effort is devoted to improve calcium-phosphate materials physico-chemical properties by tuning their degree of crystallinity and doping them with metal ions is one of the mostly researched strategies. The results found in the literature show that synthesized CaOP2O5-Nb2O5 compounds exhibit a good biocompatibility, very low cytotoxicity in respect to calciumphosphate doped with other metals and additionally can enhance human osteoblast function2,3. As of today structure of these materials is not thoroughly described. Therefore, the detailed structural investigation by means of spectroscopic studies, i.e. FTIR spectroscopy, Raman spectroscopy, XAFS spectroscopy, XPS and EDX, together with SEM imaging, XRD and BET surface area measurements, was realized to shed light on the relationship between materials structure and the presence of dopant. In this work, we show the results obtained for bioactive glass-ceramics, prepared via simple sol-gel method, with Ca/(P+Nb) molar ratio equal to 1.5 and with relative Nb contents of 0 mol% and 10 mol% of P. XRD patterns analysis shows that samples consist of tricalcium phosphate and hydroxyapatite phase. Raman spectra analysis confirms the incorporation of Nb into the material structure. Moreover, niobium doping leads to an increase in degree of crystallinity and crystallite size of the sample. Stoichiometry of the ceramics is as intended. Additionally, there is a greater proportion of carbonate groups in the doped material than in the undoped one (FTIR, Raman spectroscopy), and all samples exhibit calcium deficiency on the surface (XPS). XAFS analysis shows presence of octahedral coordination of niobium ions, with average oxidation state around +4.5 and XPS analysis indicates that on the sample surface the contribution of Nb+5 ions is greater than Nb+4 ions. Additionally it can be concluded, that Nb accumulates on materials surface.

  • Spinon excitations in the quasi-one-dimensional S=12 chain compound Cs4CuSb2Cl12
    • Thao Tran
    • Chris A. Pocs
    • Yubo Zhang
    • Michał Winiarski
    • Jianwei Sun
    • Minhyea Lee
    • Tyrel McQueen
    2020 Pełny tekst PHYSICAL REVIEW B

    The spin−1/2 Heisenberg antiferromagnetic chain is ideal for realizing one of the simplest gapless quantum spin liquids (QSLs), supporting a many-body ground state whose elementary excitations are fractional fermionic excitations called spinons. Here we report the discovery of such a one-dimensional (1D) QSL in Cs4CuSb2Cl12. Compared to previously reported S=1/2 1D chains, this material possesses a wider temperature range over which the QSL state is stabilized. We identify spinon excitations extending at T>0.8K, with a large T-linear contribution to the specific heat, γ=31.5(2)mJmol−1K−2, which contribute itinerantly to thermal transport up to temperatures as high as T=35K. At T=0.7K, we find a second-order phase transition that is unchanged by a μ0H=5T magnetic field. Cs4CuSb2Cl12 reveals new phenomenology deep in the 1D QSL regime, supporting a gapped QSL phase over a wide temperature range compared to many other experimental realizations.

  • Spirala 2 (wg Ulama) z cyklu No Quick Response
    • Krzysztof Wróblewski
    2020

    Spirala 2 (wg Stanisława Ulama) Obraz odnosi się do modelu matematycznego nazywanego Spiralą Ulama, który polega na okrężnym zapisie w polu kwadratu liczb naturalnych od 1 do nieskończoności. Taki zapis uwidacznia szczególne wzory, które powstają z położenia liczb pierwszych (niepodzielnych). Liczby pierwsze tworzą ciągi mniej lub bardziej regularne w układzie diagonalnym, poziomym i pionowym. W obrazie Spirala 2 wykorzystany został zestaw liczb od 1 do 1600. Położenia liczb pierwszych są malowane czernią i bielą, natomiast położenie pozostałych liczb kolorami podstawowymi i pochodnymi w różnej tonacji. Kolory "wędrują" progresywnie za liczbami po kształcie spirali. Sekwencyjny rytm przerywany jest położeniem liczby pierwszej. W wyniku tego zabiegu samorzutnie powstają grupy różnych form i kolorów, przy czym żadna z nich nie jest dominująca w całości układu. Poszczególne kształty są tylko cząstkami większej całości. W spirali Ulama podobnie jak w ciągu Fibonacciego występuje rodzaj harmonijnej jedności. Krzysztof Wróblewski

  • Społeczna odpowiedzialność biznesu w branży odzieżowej - perspektywa polskiego konsumenta
    • Ewa Marjańska
    • Piotr Grudowski
    • Anna Wendt
    • Mateusz Muchlado
    2020 Problemy Jakości

    Przesunięcie produkcji do krajów dotkniętych ubóstwem towarzyszy podejściu kładącemu nacisk na szybkie odpowiedzialność i tanie udostępnianie trendów modowych konsumentom oraz systemowi wytwarzania opartemu na popycie biznesu, w przemyśle odzieżowym. W artykule zwrócono uwagę na: świadomość, postawy, zachowania etyczne oraz zrównoważony sposób postrzegania jakości produktów „fast fashion” w perspektywie społecznej odpowiedzialności. Na rozwój, podstawie metody CAWI i PAPI przeprowadzono badanie polskich konsumentów deklarujących zachowania przemysł odzieżowy, nabywcze związane z „fast fashion”. Badania wykazały, że działania związane ze społeczną odpowiedzialnością fast fashion biznesu w branży odzieżowej są istotne dla klientów, jednak cena jest najważniejszym czynnikiem przy podejmowaniu decyzji o zakupie. Ocena świadomości konsumentów w zakresie CSR może posłużyć do ukierunkowania przyszłych działań edukacyjnych w tym obszarze, zwłaszcza w dobie przyspieszonej konsumpcji i celów zrównoważonego rozwoju. Wyniki badań mogą też być przesłanką do określenia kierunku działań związanych z CSR dla sprzedawców „fast fashion”.

  • Społeczna odpowiedzialność biznesu w kontekście strategii wybranych spółek posiadających istotne znaczenie dla gospodarki
    • Sebastian Skuza
    • Anna Modzelewska
    • Malwina Popiołek
    • Marta Szeluga-Romańska
    2020

    Przedmiotem badań jest analiza sposobów realizacji strategii społecznej odpowiedzialności biznesu przez przez wybrane spółki z udziałem Skarbu Państwa.

  • Stability analysis of interconnected discrete-time fractional-order LTI state-space systems
    • Łukasz Grzymkowski
    • Damian Trofimowicz
    • Tomasz Stefański
    2020 Pełny tekst International Journal of Applied Mathematics and Computer Science

    In this paper, a stability analysis of interconnected discrete-time fractional-order (FO) linear time-invariant (LTI) state-space systems is presented. A new system is formed by interconnecting given FO systems using cascade, feedback, parallel interconnections. The stability requirement for such a system is that all zeros of a non-polynomial characteristic equation must be within the unit circle on the complex z-plane. The obtained theoretical results lead to a numerical test for stability evaluation of interconnected FO systems. It is based on modern root-finding techniques on the complex plane employing triangulation of the unit circle and Cauchy’s argument principle. The developed numerical test is simple, intuitive and can be applied to a variety of systems. Furthermore, because it evaluates the function related to the characteristic equation on the complex plane, it does not require computation of state-matrix eigenvalues. The obtained numerical results confirm the efficiency of the developed test for the stability analysis of interconnected discrete-time FO LTI state-space systems.

  • Stability analysis of nanobeams in hygrothermal environment based on a nonlocal strain gradient Timoshenko beam model under nonlinear thermal field
    • Subrat Kumar Jena
    • S. Chakraverty
    • Mohammad Malikan
    2020 Pełny tekst Journal of Machinery Manufacture and Reliability

    This article is dedicated to analyzing the buckling behavior of nanobeam subjected to hygrothermal environments based on the principle of the Timoshenko beam theory. The hygroscopic environment has been considered as a linear stress field model, while the thermal environment is assumed to be a nonlinear stress field based on the Murnaghan model. The size-dependent effect of the nanobeam is captured by the nonlocal strain gradient theory (NSGT), and the governing equations of the proposed model have been derived by implementing a variational principle. The critical buckling loads have been calculated for the hinged–hinged boundary condition by incorporating the Navier approach and considering other elasticity theories such as classical elasticity theory, Eringen nonlocal elasticity theory, and strain gradient theory along with the NSGT. The present model is also validated with the pre-existing model in exceptional cases. Further, a parametric investigation has been performed to report the influence of various scaling parameters like hygroscopic environment, thermal environment, length-to-diameter ratio, small scale parameter, and length scale parameter on critical buckling loads by considering both the linear and nonlinear temperature distributions.

  • Stabilizing lactate production through repeated batch fermentation of food waste and waste activated sludge
    • Xianbao Xu
    • Wenjuan Zhang
    • Xia Gu
    • Zhichao Guo
    • Jian Song
    • Daan Zhu
    • Yanbiao Liu
    • Yanan Liu
    • Gang Xue
    • Xiang Li
    • Jacek Mąkinia
    2020 BIORESOURCE TECHNOLOGY

    Bio-valorization of organic waste streams, such as food waste and waste activated sludge, to lactic acid (LA) has recently drawn much attention. It offers an opportunity for resource recovery, alleviates environmental issues and potentially turns a profit. In this study, both stable and high LA yield (0.72 ± 0.15 g/g total chemical oxygen demand) and productivity rate (0.53 g/L•h) were obtained through repeated batch fermentation. Moreover, stable solubilization and increase in the critical hydrolase activities were achieved. Depletions of ammonia and phosphorus were correlated with the LA production. The relative abundance of the key LA bacteria genera (i.e., Alkaliphilus, Dysgonomonas, Enterococcus and Bifidobacterium) stabilized in the repeated batch reactor at a higher level (44.5 ± 2.53%) in comparison with the batch reactor (26.2 ± 4.74%). This work show a practical way for the sustainable valorization of organic wastes to LA by applying the repeated batch mode during biological treatment.

  • Standardy Profesjonalnego Public Relations
    • Jacek Barlik
    • Ewa Hope
    • Jerzy Olędzki
    • Krystyna Wojcik
    2020

    " Standardy przedstawiają wartości i pryncypia uzasadniające konieczność dokonywania odpowiednich wyborów. Public relations ma godzić interesy zleceniodawców, przedstawicieli mediów i różnych grup społeczeństwa, a przy tym pozostawać w zgodzie z normami etycznymi i odwoływać się do takich wartości jak szacunek, godność, rzetelność, uczciwość, prawda, wiarygodność, niezależność, lojalność i zaufanie. Opracowanie "Standardów profesjonalnego Public Relations" zostało przygotowane przez społeczny zespół ekspertów - autorzy dokumentu, w przekonaniu, że profesjonalizm i etyka są ze sobą nierozerwalnie połączone -zwłaszcza w dziedzinach, które - jak PR, wpływają na kondycję społeczeństwa."

  • Stanowisko laboratoryjne do badania procesów wibroakustycznych w rejonie głowicy cylindrowej silnika z zapłonem samoczynnym - wyniki badań pilotażowych
    • Jacek Rudnicki
    2020 Pełny tekst Journal of Polish CIMEEAC

    W artykule przedstawiono założenia oraz ich praktyczną realizację w odniesieniu do stanowiska laboratoryjnego przeznaczonego do badania procesów wibroakustycznych w rejonie głowicy silnika z zapłonem samoczynnym. Podstawowym założeniem podczas realizacji tego projektu było stworzenie możliwości dydaktycznych oraz naukowo – badawczych w zakresie obserwacji i rejestracji procesów drganiowych w rejonie głowicy cylindrowej silnika z zapłonem samoczynnym podczas pracy układu rozrządu napędzane go ze źródła zewnętrznego. Umożliwia to wyselekcjonowanie prawie „czystej” postaci tych procesów, pochodzących wyłącznie od pracy układu rozrządu bez zakłóceń spowodowanych pracą innych przekładni i mechanizmów w rzeczywistym silniku oraz zjawisk gazodynamicznych związanych ze spalaniem. Fakt ten pozwala na rejestrację wartości wybranych wskaźników opisujących drgania tego węzła konstrukcyjnego silnika, odpowiednie opracowanie powstałych zapisów i ich ewentualne wykorzystanie we wnioskowaniu diagnostycznym np. w zakresie oceny faz rozrządu. Innym sposobem wykorzystania tak uzyskanych wyników jest możliwość wykorzystania tych zapisów do filtracji wyników uzyskanych na obiekcie rzeczywistym czyli funkcjonującym silniku.

  • Stanowisko wizualizacji zdarzeń w systemie STRADAR – realizacja i funkcje dla operatora
    • Bartosz Czaplewski
    • Sylwester Kaczmarek
    • Jacek Litka
    2020 Pełny tekst Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    It is crucial for the Border Guard to be equipped with a communication-teleinformatic infrastructure designed to support them in efficient realization of their operational tasks. STRADAR – a system which results are presented in this paper – is such an infrastructure. It is a distributed solution for the maritime division of the border guard. The system, with the use of a network of sensors located in both stationary and mobile points collects, archives and processes information and multimedia data, which can be made available to the staff on their demand. STRADAR consists of a number of functional elements. The paper includes a detailed description of one of them. This element being Event Visualization Post EVP, which utilizes multidisplay set up in the Centrum, to display multimedia presentation of information and data for both archival and current situations.

  • Static and Dynamic Mechanical Properties of 3D Printed ABS as a Function of Raster Angle
    • Mateusz Galeja
    • Aleksander Hejna
    • Paulina Kosmela
    • Arkadiusz Kulawik
    2020 Pełny tekst Materials

    Due to the rapid growth of 3D printing popularity, including fused deposition modeling (FDM), as one of the most common technologies, the proper understanding of the process and influence of its parameters on resulting products is crucial for its development. One of the most crucial parameters of FDM printing is the raster angle and mutual arrangement of the following filament layers. Presented research work aims to evaluate different raster angles (45°, 55°, 55’°, 60° and 90°) on the static, as well as rarely investigated, dynamic mechanical properties of 3D printed acrylonitrile butadiene styrene (ABS) materials. Configuration named 55’° was based on the optimal winding angle in filament-wound pipes, which provides them exceptional mechanical performance and durability. Also in the case of 3D printed samples, it resulted in the best impact strength, comparing to other raster angles, despite relatively weaker tensile performance. Interestingly, all 3D printed samples showed surprisingly high values of impact strength considering their calculated brittleness, which provides new insights into understanding the mechanical performance of 3D printed structures. Simultaneously, it proves that, despite extensive research works related to FDM technology, there is still a lot of investigation required for a proper understanding of this process.

  • Step on It Bringing Fullwave Finite-Element Microwave Filter Design up to Speed
    • Łukasz Balewski
    • Grzegorz Fotyga
    • Adam Lamęcki
    • Michał Mrozowski
    • Martyna Mul
    • Piotr Sypek
    • Damian Szypulski
    2020 Pełny tekst IEEE MICROWAVE MAGAZINE

    There are many steps in the design of a microwave filter: mathematically describing the filter characteristics, representing the circuit as a network of lumped elements or as a coupling matrix, implementing the distributed elements, finding the initial dimensions of the physical structure, and carrying out numerical tuning using electromagnetic (EM) simulators. The whole process is painstaking and time-consuming, and it requires a great deal of engineering expertise. Microwave filters are extremely complex geometric structures, and their simple circuits are often quite hard to represent. Moreover, manufacturing them is costly: to be sure that the hardware resulting from the design will meet the performance goals, rigorous computer tools are used to determine the physical dimensions and evaluate all of the adjustments at the final stage. This last stage is particularly challenging, and advanced computational techniques are required.

  • Storage electric multiple units on partially electrified suburban railway lines
    • Aleksander Jakubowski
    • Natalia Karkosińska-Brzozowska
    • Krzysztof Karwowski
    • Andrzej Wilk
    2020 Pełny tekst Przegląd Elektrotechniczny

    The paper presents possible environmental, energy and economical gains implied by replacing conventional traction vehicles with independent powered electric multiple units (IPEMU) on partially electrified suburban railways. IPEMUs can operate in two modes of power supply – using overhead catenary or onboard battery storage. Appropriate computer simulations were carried out in the Matlab program, indicating the parameters of storage electric multiple units.

  • Strategic Flexibility as a Mediator in Relationship between Managerial Decisions and Organizational Learning: Ambidexterity Perspective
    • Monika Stelmaszczyk
    • Agata Pierścieniak
    2020 Pełny tekst European Research Studies Journal

    Purpose: The purpose of the article is to determine strategic flexibility in the relationship between managerial decisions and organizational learning. The analyses are conducted in the ambidexterity convection. Design/Methodology/Approach: The study was conducted at a textile company. The company is a leader in the textile recycling industry in Poland. Empirical data were collected using the PAPI technique. The survey questionnaire was addressed to all 138 company managers. The response rate was 57%. Linear regression analyses were performed to test the research hypotheses. The significance of indirect effects was checked using the bootstrap method. Findings: Our findings show that as the ambidexterity oriented managerial decisions increases, the organizational learning ambidexterity increases. This relationship mediates strategic flexibility through variable flexibility resources and flexibility coordination. In fact, we have indicated the effect of double mediation. This means that there is a relationship between the independent variable and the dependent variable because of interacting resource flexibility and coordination flexibility. Practical Implications: Our study shows that managerial decisions in the company will become more conducive for improving current ideas and introducing new ideas, including ways of their implementation if the enterprise undertakes the proposed steps. They include the acquisition of resources, to develop practical skills, to care in maintaining relatively low costs and shortening task execution duration, to be able to switch to alternative uses of resources. Originality/Value: The value of our research is gaining new knowledge about strategic flexibility. Arguing its necessity for the existence of relationships between managerial decisions and organizational learning, using the ambidexterity convention, improves the knowledge regarding the identity of this category of flexibility.

  • Stratification of nano-pigments in anti-corrosive coatings by means of magnetic field
    • Andrzej Miszczyk
    • Kazimierz Darowicki
    2020 Pełny tekst PROGRESS IN ORGANIC COATINGS

    The concept of self-stratification of coatings, although attractive, causes difficulties in its practical use, especially when pigments are added to the resins. An alternative way of obtaining a multilayer structure in a single step was presented. Using the inhomogeneous magnetic field and magnetically active components of the coating, the possibility of vertically graded differentiation of the one layer properties has been verified. For this purpose, the magnetic properties of nickel ferrite (NiFe2O4) nano-particles and magnetic field for their transport in a wet coating were used. It has been shown that it is possible to use the magnetic field to transport magnetic ferrite, used as active anticorrosive pigments, near the coating/substrate interface, in the initially homogeneous wet paint layer, during film formation. These results prove that magnetic ferrite pigments can be magnetically manipulated in liquid coating layer applied on the substrate. Using the impedance spectroscopy technique, it was possible to detect stratification by analyzing complex capacity diagrams. As a result of impedance tests, better anti-corrosive properties of the system hardened in the presence of the magnetic field were demonstrated.

  • Stream Reasoning to Improve Decision-Making in Cognitive Systems
    • Caterine Silva de Oliveira
    • Franco Giustozzi
    • Cecilia Zanni-Merk
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Pełny tekst CYBERNETICS AND SYSTEMS

    ABSTRACT Cognitive Vision Systems have gained a lot of interest from industry and academia recently, due to their potential to revolutionize human life as they are designed to work under complex scenes, adapting to a range of unforeseen situations, changing accordingly to new scenarios and exhibiting prospective behavior. The combination of these properties aims to mimic the human capabilities and create more intelligent and efficient environments. Contextual information plays an important role when the objective is to reason such as humans do, as it can make the difference between achieving a weak, generalized set of outputs and a clear, target and confident understanding of a given situation. Nevertheless, dealing with contextual information still remains a challenge in cognitive systems applications due to the complexity of reasoning about it in real time in a flexible but yet efficient way. In this paper, we enrich a cognitive system with contextual information coming from different sensors and propose the use of stream reasoning to integrate/process all these data in real time, and provide a better understanding of the situation in analysis, therefore improving decision-making. The proposed approach has been applied to a Cognitive Vision System for Hazard Control (CVP-HC) which is based on Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA) and has been designed to ensure that workers remain safe and compliant with Health and Safety policy for use of Personal Protective Equipment (PPE).

  • Stress Monitoring System for Individuals with Autism Spectrum Disorders
    • Michał Tomczak
    • Marek Wójcikowski
    • Bogdan Pankiewicz
    • Jacek Łubiński
    • Jakub Majchrowicz
    • Daria Majchrowicz
    • Anna Walasiewicz
    • Tomasz Kiliński
    • Małgorzata Szczerska
    2020 Pełny tekst IEEE Access

    In this article, a stress monitoring system tailored for individuals with Autism Spectrum Disorders (ASD) and developed for the educational institution is presented. People with ASD face problems with effective stress management due to their high self-perceived levels of stress, poor ability to cope with it, and dificulties with the accurate detection of the source of stress. Consistently, being able to measure stress appears to be highly vital for this specifc group. The design and construction of the measuring system are introduced. The stress monitoring system including autonomic wearable device (wristband), both the electronics and mechanical part, as well as the software application for data analysis are shown. The wearable device includes sensors for measuring heart rate, skin resistance, temperature and movement. A dedicated software application allows for generating reports to evaluate therapeutic effects. The complex stress monitoring system has been tested in an educational institution. It can provide signifcant support in the stress management of people with ASD and become a meaningful assistance in the therapy of neurodiverse individuals.

  • Stress-driven nonlocal elasticity for nonlinear vibration characteristics of carbon/boron-nitride hetero-nanotube subject to magneto-thermal environment
    • Hamid M. Sedighi
    • Mohammad Malikan
    2020 Pełny tekst PHYSICA SCRIPTA

    Stress-driven nonlocal theory of elasticity, in its differential form, is applied to investigate the nonlinear vibrational characteristics of a hetero-nanotube in magneto-thermal environment with the help of finite element method. In order to more precisely deal with the dynamic behavior of size-dependent nanotubes, a two-node beam element with six degrees-of freedom including the nodal values of the deflection, slope and curvature is introduced. In comparison with the conventional beam element, the vector of nodal displacement for the proposed element has one additional component indicating the nodal curvature to comply with the stress-driven nonlocal beam model. The nonlinear term associated with the von Kármán strain is included in the governing equation of motion and it is assumed that the nanotube structure is exposed to temperature changes and surrounded by a magnetic field. The obtained results endorsing the amplitude-dependence of the nonlinear frequencies are justified compared to those reported in the literature and a detailed study is conducted to explore the effect of different parameters on the vibrational behavior of the considered nano-hetero-structure.

  • Striking elements - A lifebelt or a fad? Searching for an effective way of adapting abandoned churches.
    • Agnieszka Szuta
    • Jakub Szczepański
    2020 Pełny tekst Frontiers of Architectural Research

    Are avant-garde elements added to historical objects as a temporary fashion to fulfill the aspirations of designers or an attempt to draw attention to themselves? It may be the exact opposite, and this type of controversial project is the best lifebelt for such monuments. This article explores issues related to external avant-garde elements added to adapted churches and their influence on the efficiency of such adaptation projects. Gothic churches located in the north of Europe that have changed their religious function, entirely or in part, were considered. This work examined former churches in Maastricht, namely, the Minorite Church, the Church of the Kruisheren Monastery, the Dominican Church, as well as Polish churches located in Gda nsk, including St. John’s Church and St. Catherine’s Church. This article attempted to identify the factors that contribute to the successful adaptation of former churches and the benefits and drawbacks of adopting avant-garde design solutions. Results of this study might provide valuable inspiration for other churches that are losing worshippers. This study was conducted on the basis of a wide range of literature, statistical data, logical reasoning, and comparative methods. Observations from selected edifices were checked for their correlation over time. This study also included in situ investigations.