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Gdańsk University of Technology

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  • HYGRO-MAGNETIC VIBRATION OF THE SINGLE-WALLED CARBON NANOTUBE WITH NONLINEAR TEMPERATURE DISTRIBUTION BASED ON A MODIFIED BEAM THEORY AND NONLOCAL STRAIN GRADIENT MODEL
    • Jena Subrat Kumar
    • S. Chakraverty
    • Mohammad Malikan
    • Hamid M. Sedighi
    2020 Full text International Journal of Applied Mechanics

    In this study, vibration analysis of single-walled carbon nanotube (SWCNT) has been carried out by using a refined beam theory, namely one variable shear deformation beam theory. This approach has one variable lesser than a contractual shear deformation theory such as first-order shear deformation theory (FSDT) and acts like classical beam approach but with considering shear deformations. The SWCNT has been placed in an axial or longitudinal magnetic field which is also exposed to both the hygroscopic as well as thermal environments. The thermal environment is considered as nonlinear thermal stress field based on the Murnaghan’s model whereas the hygroscopic environment is assumed as a linear stress field. The size effect of the SWCNT has been captured by both the nonlocal and gradient parameters by employing the Nonlocal Strain Gradient Theory (NSGT). Governing equation of motion of the proposed model has been developed by utilizing the extended Hamilton’s principle and the non- dimensional frequency parameters have been computed by incorporating the Navier’s approach for Hinged-Hinged (HH) boundary condition. The proposed model is validated with the existing model in special cases, by comparing the non- dimensional frequency parameters, displaying an excellent agreement. Further, a parametric study has been conducted to analyze the impact of nonlocal parameter, gradient parameter, thermal environment, hygroscopic environment, and magnetic field intensity on the non-dimensional frequency parameters. Also, results for some other theories like Classical Elasticity Theory (CET), Nonlocal Elasticity Theory (NET), and Strain Gradient Theory (SGT) have been presented along with the NSGT.

  • Hyperbolic Asynchronous Method of a Radio Navigation Technique
    • Ryszard Katulski
    • Jarosław Sadowski
    • Jacek Stefański
    • Wojciech Siwicki
    2020 Full text Applied Sciences-Basel

    Humans have always wanted to determine position in an unknown environment. At the beginning methods were simple. They were based on the observation of characteristic points, in the case of shipping additional observations of the coastline. Then came navigation based on astronomical methods (astronavigation). At the beginning of the XX-century a new way of determining the current location was developed. It has used radiowave signals. First came radio-beacons. Then ground-based systems came. Currently satellite systems are being used. At present, the most popular one is Global Positioning System (GPS). This system is fully controlled by the Department of Defense, and only the U.S. forces and their closest allies have been guaranteed accuracy offered by the system. Armies of other countries can only use the civilian version. This situation has engendered the need for an independent radiolocation system. This article describes the construction and operation of such a technology demonstrator that was developed at Gdansk University of Technology. The main advantage of the system is managing without the chain organization of the reference stations, which work now with each other asynchronously. This article demonstrates the functionality of such system. It also presents results and analysis of its effectiveness.

  • Hysteresis curves for some periodic and aperiodic perturbations in magnetosonic flow
    • Anna Perelomova
    2020 Full text PHYSICS OF PLASMAS

    A thermodynamic relation between perturbations of pressure and mass density in the magnetohydrodynamic flow is theoretically studied. Planar magnetohydrodynamic perturbations with the wave vector, which forms a constant angle with the equilibrium magnetic field, are under study. The theory considers thermal conduction of a plasma and the deviation from adiabaticity of a flow due to some kind of heating–cooling function. It also considers nonlinear distortion of a waveform and nonlinear excitation of the entropy mode in the field of intense magnetosonic perturbations. In some conditions, the total density of a plasma enlarges over a cycle of magnetosonic perturbations. These conditions depend on the type of magnetosonic waveform, heating–cooling function, thermal conduction, and equilibrium parameters of a plasma. They depend also on the angle between the wave vector and the magnetic field. The diagrams in the plane of total variation of pressure vs total variation of density indicate the nonlinear phenomena and irreversible processes in a flow. Harmonic perturbation and a bipolar impulse of pressure are considered as magnetosonic exciters of the entropy mode. Exemplary diagrams are plotted and discussed for these particular cases of exciters.

  • I, Robot: between angel and evil
    • Magdalena Popowska
    2020

    The boosting of most digital innovations within recent technology progress by artificial intelligence (AI) constitutes a growing topic of interest. Besides its technical aspects, increasing research activity may be observed in the domain of security challenges, and therefore of responsibility related to the controlled or hypothetically uncontrolled or autonomous emergence of AI solutions. Consequently, responsibility and ethics in the creation of AI-based systems, and thus also solutions (machine ethics), have been, especially recently, at the center of debates and regulatory activities. The present chapter, after a short introduction to the AI concept, next provides an overview of considerations on ethical aspects of AI’s wide deployment. It explores ethical considerations based on a literature review and provides some recommendations emanating both from regulatory effort at international level, and from the work of experts and scholars.

  • IATUL Seminar 2019 – ważne wydarzenie wpisujące się w rozwój działań Biblioteki Politechniki Gdańskiej na polu współpracy międzynarodowej.
    • Urszula Szybowska
    2020 Full text Pismo PG

    Celem IATUL Seminar 2019 (Organizing the Open Science Framework – Strategies and Legal Aspects) było podsumowanie aktualnego stanu otwartości w nauce w Polsce i na świecie. Problematyka podejmowana na konferencji skupiała się na przeglądzie polityki repozytoriów instytucjonalnych i usług związanych z zarządzaniem danymi badawczymi. Poruszano także zagadnienia dotyczące aspektów prawnych związanych ze zbieraniem, przechowywaniem i wykorzystywaniem danych badawczych. IATUL Seminar 2019 zostało zorganizowane przez Bibliotekę Politechniki Gdańskiej we współpracy z IATUL (International Association of University Libraries), międzynarodowym Stowarzyszeniem Bibliotek Uniwersyteckich.

  • ICT and social development. Conceptual considerations.
    • Ewa Lechman
    • Franciszek Kutrzeba
    • Kai Mustakoski
    2020

    This chapter is intended to provide basic ideas and concepts related to technology, technological progress and society. It explains how and why technology and society are interrelated, forming a dynamic, complex and interdependent evolutionary system. It introduces the terms Digital (ICT) Revolution and information and communication technologies (ICTs), showing elementary features of new technologies. The chapter explains why ICTs are labelled as general purpose technologies. Finally, it briefly discusses the potential channels through which information and communication technologies may affect society, emphasizing some potential benefits but also threats and challenges that society meets along with fast worldwide adoption of technologies.

  • Idea urbanistyczna Juliana Rummla i jej wpływ na międzywojenne plany Gdyni = The Urban Idea of Jukiab Rummel and Its Influence on the Interwar Plans of Gdynia
    • Maria Sołtysik
    2020

    Julian Rummel nie był ani architektem ani urbanistą. Był inżynierem budowy okrętów, działaczem gospodarczym, jednym w wielkich orędowników budowy portu i miasta Gdyni oraz współtwórcą polskiej polityki morskiej II Rzeczypospolitej. W połowie 1924 roku, kiedy rozpoczęto w Gdyni przebudowę otwartego zaledwie rok wcześniej Portu Tymczasowego na wielki, uniwersalny port stały, Julian Rummel był pierwszym którzy zwracali uwagę na pilną potrzebę budowy miasta przy powstającym porcie. W artykule napisanym w grudniu 1924 roku zaprezentował swoją wizję urbanistyczną nowego miasta i pomimo że koncepcja ta została zaprezentowana jedynie w formie opisowej, przedstawiała bardzo nowoczesne podejście do problematyki przestrzennej. Artykuł ten został zatytułowany Miasto Gdynia. Przyczynek do opracowania planu miasta. Autor odnosi się w nim do jednej z najważniejszych teorii urbanistycznych początków XX stulecia – do idei miasta-ogrodu, proponując zastosowanie jej do konstruowania planu ogólnego całego zespołu miejskiego Gdyni. Poza tym, Rummel w sposób bardzo sugestywny zarysował w tym artykule przyszły kształt Dzielnicy Reprezentacyjnej miasta, z dużym placem nadmorskim, Bazyliką Morską i ratuszem. Trzeba przy tym zaznaczyć, że naszkicowana przez niego w 1924 roku wizja została opublikowana półtora roku przed sporządzeniem pierwszych planów urbanistycznych Gdyni. W rezultacie też, okazała się ona stanowić inspirację dla wielu architektów-urbanistów projektujących miasto w okresie międzywojennym, a zwłaszcza dla projektantów planów z lat 1926 i 1938. W ich właśnie projektach znaleźć możemy w sposób najpełniejszy realizację wizji urbanistycznej Gdyni, przedstawionej przez Juliana Rummla już w pierwszej połowie lat dwudziestych.

  • Identification of Parameters Influencing the Accuracy of the Solution of the Nonlinear Muskingum Equation
    • Dariusz Gąsiorowski
    • Romuald Szymkiewicz
    2020 Full text WATER RESOURCES MANAGEMENT

    Two nonlinear versions of the Muskingum equation are considered. The difference between both equations relates to the exponent parameter. In the first version, commonly used in hydrology, this parameter is considered as free, while in the second version, it takes a value resulting from the kinematic wave theory. Consequently, the first version of the equation is dimensionally inconsistent, whereas the proposed second one is consistent. It is shown that the difference between the results provided by both versions of the nonlinear Muskingum equation depends on the longitudinal bed slope of a channel. For an increasing slope, when a propagating wave becomes more kinematic, the value of the exponent considered as the free parameter tends to its value resulting from the kinematic wave theory. Consequently, when the character of an open channel flow tends to a kinematic one, the dimensionally inconsistent version of the nonlinear Muskingum equation becomes a consistent one. The results of the numerical analysis suggest that apart from the parameters involved in the Muskingum equation, usually considered as free, the parameters of the numerical method of the solution (the number of reservoirs and the time step) should be considered also as free parameters. This conclusion results from the fundamental property of the Muskingum equation, relating to the numerical roots of the wave attenuation process. All numerical examples and tests relate to the solutions of the system of Saint Venant equations, considered as the benchmark.

  • Identification of Substrates of Cytoplasmic Peptidyl-Prolyl Cis/Trans Isomerases and Their Collective Essentiality in Escherichia Coli
    • Gracjana Klein-Raina
    • Paweł Wojtkiewicz
    • Daria Biernacka
    • Anna Stupak
    • Patrycja Gorzelak
    • Satish Raina
    2020 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Protein folding often requires molecular chaperones and folding catalysts, such as peptidyl-prolyl cis/trans isomerases (PPIs). The Escherichia coli cytoplasm contains six well-known PPIs, although a requirement of their PPIase activity, the identity of their substrates and relative enzymatic contribution is unknown. Thus, strains lacking all periplasmic and one of the cytoplasmic PPIs were constructed. Measurement of their PPIase activity revealed that PpiB is the major source of PPIase activity in the cytoplasm. Furthermore, viable Δ6ppi strains could be constructed only on minimal medium in the temperature range of 30–37 °C, but not on rich medium. To address the molecular basis of essentiality of PPIs, proteins that aggregate in their absence were identified. Next, wild-type and putative active site variants of FkpB, FklB, PpiB and PpiC were purified and in pull-down experiments substrates specific to each of these PPIs identified, revealing an overlap of some substrates. Substrates of PpiC were validated by immunoprecipitations using extracts from wild-type and PpiC-H81A strains carrying a 3xFLAG-tag appended to the C-terminal end of the ppiC gene on the chromosome. Using isothermal titration calorimetry, RpoE, RseA, S2, and AhpC were established as FkpB substrates and PpiC’s PPIase activity was shown to be required for interaction with AhpC.

  • Identification of the Agile Mindset and Its Comparison to the Competencies of Selected Agile Roles
    • Jakub Miler
    • Paulina Gaida
    2020

    In this paper we present the results of the identification and evalua-tion of the elements of an agile mindset as well as its comparison to the compe-tence models for the roles of Scrum Master, Product Owner and agile analyst. We have identified 70 unique agile mindset elements from literature and 5 in-terviews with experts. Based on an opinion survey among 52 agile practitioners we evaluated the importance of 26 selected elements of the agile mindset to the effectiveness of an agile team. The competence models contain 29 competen-cies of a Scrum Master, 16 competencies of a Product Owner and 40 competen-cies of an agile analyst, divided into behavioral, technical and contextual ones. We discuss which agile mindset elements are important to each agile role. This paper is an extended version of the paper titled “On the Agile Mindset of an Ef-fective Team – An Industrial Opinion Survey” presented at the 3nd International Conference on Lean and Agile Software Development LASD 2019 [28]

  • Il"valore aggiunto" delle biografie imprenditoriali
    • Luciano Segreto
    2020

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  • Image Representation for Cognitive Systems Using SOEKS and DDNA: A Case Study for PPE Compliance
    • Caterine Silva de Oliveira
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Full text

    Cognitive Vision Systems have gained significant interest from academia and industry during the past few decade, and one of the main reasons behind this is the potential of such technologies to revolutionize human life as they intend to work under complex visual scenes, adapting to a comprehensive range of unforeseen changes, and exhibiting prospective behavior. The combination of these properties aims to mimic the human capabilities and create more intelligent and efficient environments. Nevertheless, preserving the environment such as humans do still remains a challenge in cognitive systems applications due to the complexity of such process. Experts believe the starting point towards real cognitive vision systems is to establish a representation which could integrate image/video modularization and virtualization, together with information from other sources (wearable sensors, machine signals, context, etc.) and capture its knowledge. In this paper we show through a case study how Decisional DNA (DDNA), a multi-domain knowledge structure that has the Set of Experience Knowledge Structure (SOEKS) as its basis can be utilized as a comprehensive embedded knowledge representation in a Cognitive Vision System for Hazard Control (CVP-HC). The proposed application aims to ensure that workers remain safe and compliant with Health and Safety policy for use of Personal Protective Equipment (PPE) and serves as a showcase to demonstrate the representation of visual and non-visual content together as an experiential knowledge in one single structure.

  • Image transmission in UAV MIMO UWB-OSTBC system over Rayleigh channel using multiple description coding (MDC)
    • Ali Arshaghi
    • Navid Razmjooy
    • Vania V. Estrela
    • Paweł Burdziakowski
    • Douglas A. Nascimento
    • Anand Deshpande
    • Prashant P. Patavardhan
    2020 Full text

    Orthogonal Space-Time Block Codes (OSTBC) and multiple-input-multiple-output (MIMO) communication system are new techniques with high performance that have many applications in wireless telecommunications. This chapter presents an image transfer technique for the unmanned aerial vehicle (UAV) in a UWB system using a hybrid structure of the MIMO-OSTBC wireless environment in multiple description coding (MDC) deals. MDC technique for image transmission is a new approach in which there is no record of it so far. This ensures that in the packet loss scenario due to channel errors, images with acceptable quality with no need for retransmission can be reconstructed. The proposed system is implemented using a different number of transmitter and receiver antennas UAV. Assuming a Rayleigh model for the communication channels, the MDC image transmission performance is compared with single description coding (SDC). Experimental results confirm that the proposed hybrid method has better performance than the SDC.

  • Immittance Studies of Bi6Fe2Ti3O18 Ceramics
    • Agata Lisińska-Czekaj
    • Dionizy Czekaj
    • Barbara Garbarz-Glos
    • Wojciech Bąk
    2020 Full text Materials

    Results of studies focusing on the electric behavior of Bi6Fe2Ti3O18 (BFTO) ceramics are reported. BFTO ceramics were fabricated by solid state reaction methods. The simple oxides Bi2O3, TiO2, and Fe2O3 were used as starting materials. Immittance spectroscopy was chosen as a method to characterize electric and dielectric properties of polycrystalline ceramics. The experimental data were measured in the frequency range D = (101–107) Hz and the temperature range DT = (120–200) C. Analysis of immittance data was performed in terms of complex impedance, electric modulus function, and conductivity. The activation energy corresponding to a non-Debye type of relaxation was found to be EA = 0.573 eV, whereas the activation energy of conductivity relaxation frequency was found to be EA = 0.570 eV. An assumption of a hopping conductivity mechanism for BFTO ceramics was studied by ‘universal’ Jonscher’s law. A value of the exponents was found to be within the “Jonscher’s range” (0.54 n 0.72). The dc-conductivity was extracted from the measurements. Activation energy for dc-conductivity was calculated to be EDC = 0.78 eV, whereas the dc hopping activation energy was found to be EH = 0.63 eV. The obtained results were discussed in terms of the jump relaxation model.

  • Immunosuppressive properties of amino acid and peptide derivatives of mycophenolic acid
    • Agnieszka Siebert
    • Grzegorz Cholewiński
    • Piotr Trzonkowski
    • Janusz Rachoń
    2020 Full text EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY

    Mycophenolic acid (MPA) was coupled with amino acids and biologically active peptides including derivatives of tuftsin to modify its immunosuppressive properties. Both amino acid unit in the case of simple MPA amides and modifications within peptide moiety of MPA - tuftsin conjugates influenced the observed activity. Antiproliferative potential of the obtained conjugates was investigated in vitro and MPA amides with threonine methyl ester and conjugate of MPA with retro-tuftisin occurred to be more selective against PBMC in comparison to parent MPA. Both amino acid and peptide derivatives of MPA acted as inosine-5'-monophosphate dehydrogenase (IMPDH) inhibitors.

  • Impact of Spatial Noise Correlation on Bearing Accuracy in DIFAR Systems
    • Mariusz Rudnicki
    • Jacek Marszal
    • Roman Salamon
    2020 Full text Archives of Acoustics

    DIFAR type underwater passive systems are one of the more commonly used tools for detecting submarines. At the design stage, which usually uses computer simulations, it is necessary to generate acoustic noise of the sea. It has been shown that correlating noise significantly reduces these errors compared to the assumption that noise is uncorrelated. In addition, bearing errors have been shown to be the same in systems with a commonly used antenna containing five hydrophones, as in a system without a central hydrophone, which may be useful in some DIFAR system design solutions.

  • Impact of the anion and chalcogen on the crystal structure and properties of 4,6-dimethyl-2-pyrimido(thio)nium halides
    • Andrzej Okuniewski
    • Damian Rosiak
    • Jarosław Chojnacki
    2020 Full text Acta Crystallographica Section C-Structural Chemistry

    By the reaction of urea or thiourea, acetylacetone and hydrogen halide (HF, HBr or HI), we have obtained seven new 4,6-dimethyl-2-pyrimido(thio)nium salts, which were characterized by single-crystal X-ray diffraction, namely, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium bifluoride, C₆H₉N₂O⁺·HF₂⁻ or (dmpH)F₂H, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium bromide, C₆H₉N₂O⁺·Br⁻ or (dmpH)Br, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium iodide, C₆H₉N₂O⁺·I⁻ or (dmpH)I, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium iodide–urea (1/1), C₆H₉N₂O⁺·I⁻·CH₄N₂O or (dmpH)I·ur, 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium bifluoride–thiourea (1/1), C₆H₉N₂S⁺·HF₂⁻·CH₄N₂S or (dmptH)F₂H·tu, 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium bromide, C₆H₉N₂S⁺·Br⁻ or (dmptH)Br, and 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium iodide, C₆H₉N₂S⁺·I⁻ or (dmptH)I. Three HCl derivatives were described previously in the literature, namely, 4,6-dimethyl-2-oxo-2,3-dihydropyrimidin-1-ium chloride, (dmpH)Cl, 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium chloride monohydrate, (dmptH)Cl·H₂O, and 4,6-dimethyl-2-sulfanylidene-2,3-dihydropyrimidin-1-ium chloride–thiourea (1/1), (dmptH)Cl·tu. Structural analysis shows that in 9 out of 10 of these compounds, the ions form one-dimensional chains or ribbons stabilized by hydrogen bonds. Only in one compound are parallel planes present. In all the structures, there are charge-assisted N⁺—H∙∙∙X⁻ hydrogen bonds, as well as weaker Cₐᵣ⁺—H∙∙∙X⁻ and π⁺∙∙∙X⁻ interactions. The structures can be divided into five types according to their hydrogen-bond patterns. All the compounds undergo thermal decomposition at relatively high temperatures (150–300°C) without melting. Four oxopyrimidinium salts containing a π⁺∙∙∙X⁻∙∙∙π⁺ sandwich-like structural motif exhibit luminescent properties.

  • Impact of the trap–assisted recombination in the perovskite solar cells
    • Damian Głowienka
    • Dong Zhang
    • Mehrdad Najafi
    • Francesco Di Giacomo
    • Jędrzej Szmytkowski
    • Yulia Galagan
    2020 Full text

    To achieve the highest performance using perovskite solar cells it is necessary to understand all the dominant mechanisms which affect the operation of solar cell. Here, we have investigated the bulk and interface trap–assisted recombination processes in the solar cells with p–i–n architecture. These studies are based on the numerical and experimental methods to get better understanding of these physical processes. The following results are useful for optimization of the performance of perovskite solar cells.

  • Impact performance of novel multi-layered prepacked aggregate fibrous composites under compression and bending
    • G. Murali
    • Sallal R. Abid
    • Y.H. Mugahed Amran
    • Hakim Abdelgader
    • Roman Fediuk
    • Arikatla Susrutha
    • K. Poonguzhali
    2020 Structures

    Multi-layered Prepacked aggregate fibrous composite (MLPAFC) is a new type of concrete, which is prepared in two subsequent stages of aggregate-fibre skeleton prepacking and cementitious grouting. In this study, ten MLPAFC mixtures were prepared in three subsequent layers incorporating different contents of four different types of steel fibres. Long and short hooked-end and crimped steel fibers were adopted with 3.0 and 1.5% dosages for the outer and interior layers, respectively. In-between the three MLPAFC layers, two layers of Glass Fiber Mesh (GFM) were inserted in five of the ten mixtures. The impact response of the MLPAFC mixtures was evaluated using two test methods. In the first, the ACI 544-2R repeated free-falling weight test was followed using disk specimens, while flexural free-falling weight on prism specimens was the second adopted impact test. Moreover, Weibull distribution was used to statistically analyse the discrepancies of the obtained experimental impact records. The impact tests results revealed that MLPAFC can absorb significantly high energy under falling weight impact due to its structure and the dual crack arresting activity of both steel fibers and GFM. The cracking number of impacts of MLPAFC cylindrical specimens without GFM was increased by approximately 530–870% compared reference specimens, while increment percentages reaching 1350% were recorded at failure stage. The impact resistance of MLPAFC prisms under flexural impact was noticeably improved, yet with lower percentages than cylindrical specimens. The insertion of intermediate GFMs let to additional developments in the impact strength of both cylindrical and prism specimens.

  • Impact response of two-layered grouted aggregate fibrous concretecomposite under falling mass impact
    • M. K. Haridharan
    • S. Matheswarana
    • G. Murali
    • Sallal R. Abid
    • Roman Fediuk
    • Y.h. Mugahed Amran
    • Hakim Abdelgader
    2020 CONSTRUCTION AND BUILDING MATERIALS

    Two-layered Grouted Aggregates Fibrous Concrete Composite (TGAFCC) is a new category concrete which became popular recently and attracted the attention of researchers globally. Recent studies indicated that TGAFCC has notable improvement in mechanical properties, which has been sufficiently documented. However, the impact behaviour of TGAFCC when combined with Glass Fibre Mesh (GFM) and Textile Fibre Mesh (TFM) is still unexplored. The research objective is to study the effect of GFM and TFM insertion in TGAFCC against the drop hammer impact. Twenty one TGAFCC mixtures were prepared and divided into two series; non-fibrous concrete and fibrous concrete. The combined action of GFM and TFM of various diameters were inserted between the two layers and tested experimentally against drop mass impact. Additionally, all fibrous specimens were reinforced with a constant 3% dosage of 5D hooked end fibre. All specimens were tested under repeated drop mass impact as per ACI Committee 544. The impacts number or number of blows till the first visible crack and failure, impact energy at the first visible crack and failure, impact ductility index and cracking configuration were examined. Besides, Weibull distribution was used to examine the variations in the test results, where impact numbers were presented using the reliability function. The research findings indicate that inserting GFM and TFM between the two layers combined with 5D hooked end steel fibres, provided high impact resistance, higher absorbed energy and prolonged failure duration. Increasing the diameters of the GFM and TFM insertions, in both non-fibrous and fibrous concrete resulted in increasing the impact numbers till the first visible crack and failure. The experimental findings confirm that the major contribution of impact resistance comes from the 5D hooked end steel fibres, while the share of the intermediate meshes was significantly lower.

  • Implant system for treatment of the orbital floor defects of blowout fractures in the maxillofacial region using polypropylene yarn and bioactive bone cement
    • Marcin Wekwejt
    • Damroka Etmańska
    • Aleksandra Halman
    • Anna Pałubicka
    • Beata Świeczko-Żurek
    • Grzegorz Gajowiec
    2020 Full text JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS

    Fractures in the craniofacial region are a serious problem in terms of treatment. The most reasonable solution is the use of individual implants dedicated to a specific patient. The aim of this study was to develop the implant system specifically for treatment of the orbital floor defects of blowout fractures of maxillofacial region, using polypropylene yarn and bone cement. Three types of bone cement were used to fix the polypropylene yarn: unmodified, antibiotic‐loaded, and modified with nanometals. The following research was carried out: selection of cement production parameters, assessment of the curing time, measurement of polymerization temperature, an analysis of microstructure and surface topography, evaluation of wettability, measurement of microhardness, and studies of bactericidal effectiveness. The research confirms the possibility of using bone cement and polypropylene yarn for an individual implant, dedicated to the fractures treatment in the maxillofacial region. Moreover, the bactericidal properties of the proposed modifications for bone cement have been verified; hence, bioactive cements are recommended for use in the case of infectious complications.

  • Implementation of advanced micropollutants removal technologies in wastewater treatment plants (WWTPs) - Examples and challenges based on selected EU countries
    • Klaudia Kosek
    • Aneta Łuczkiewicz
    • Sylwia Fudala-Książek
    • Katarzyna Jankowska
    • Małgorzata Szopińska
    • Ola Svahn
    • Jens Tränckner
    • Alena Kaiser
    • Valdas Langas
    • Erland Björklund
    2020 Full text ENVIRONMENTAL SCIENCE & POLICY

    The accumulation of micropollutants (MPs) and their increasing concentration in the aquatic environment are an emerging issue for water quality in the world. The complex web of exposure pathways, as well as the variety in the chemical structure and potency of MPs, represents enormous challenges for researchers and policy initiatives. In order to manage MPs, it has to be decided which of them have to be reduced and to what extent, where in the water cycle this would be the most efficient and which technical means that should be applied to be sustainable. All of these aspects require a knowledge of MPs abundance, properties, fate and impact in the environment, which is essentially determined by two related features: the sources and the physico-chemical characteristics of MPs. Micropollutants including pharmaceuticals, antibiotics and hormones can enter the aquatic environment through both diffuse and point sources, but in urbanised regions wastewater treatment plants (WWTPs) play a crucial role in their dissemination. Conventional WWTPs are effective in removal of macropollutants (e.g. nutrients, suspended solids and some trace elements), while MPs may go through the treatment unchanged or be removed at different rates. Most of the EU countries are convinced that the presence of MPs in the environment poses a serious problem, particularly in highly populated regions where surface water resources serve as a source of potable water. Presently, various technical solutions are available and have been proven possible to integrate with existing treatment processes in an expedient manner. The solutions that have been evaluated are mainly based on ozonation and/or activated carbon treatment technologies which may definitely be considered the most effective compared to the costs incurred.

  • Implementation of Hermite-Ritz method and Navier’s Technique for Vibration of Functionally Graded Porous Nanobeam Embedded in Winkler-Pasternak Elastic Foundation Using bi-Helmholtz type of nonlocal elasticity
    • Subrat Kumar Jena
    • S. Chakraverty
    • Mohammad Malikan
    • Hamid M. Sedighi
    2020 Full text Journal of Mechanics of Materials and Structures

    Present study is devoted to investigating the vibration characteristics of Functionally Graded (FG) porous nanobeam embedded in an elastic substrate of Winkler-Pasternak type. Classical beam theory (CBT) or Euler-Bernoulli beam theory (EBT) has been incorporated to address the displacement of the FG nanobeam. Bi-Helmholtz type of nonlocal elasticity is being used to capture the small scale effect of the FG nanobeam. Further, the nanobeam is assumed to have porosity, distributed evenly along the thickness throughout the cross-section. Young’s modulus and mass density of the nanobeam are considered to vary along the thickness from ceramic to metal constituents in accordance with power-law exponent model. A numerically efficient method, namely the Hermite-Ritz method, is incorporated to compute the natural frequencies of Hinged-Hinged (HH), Clamped-Hinged (CH), and Clamped-Clamped (CC) boundary conditions. A closed-form solution is also obtained for Hinged-Hinged (HH) boundary condition by employing Navier’s technique. The advantages of using Hermite polynomials as shape functions are orthogonality, a large domain that makes the method more computationally efficient and avoids ill-conditioning for higher values of polynomials. Additionally, the present results are validated with other existing results in special cases demonstrating excellent agreement. A comprehensive study has been carried out to justify the effectiveness or convergence of the present model or method. Likewise, impacts of various scaling parameters such as Helmholtz and bi-Helmholtz types of nonlocal elasticity, porosity volume fraction index, power-law exponent, and elastic foundation on frequency parameters have been investigated.

  • Implementation of spatial/polarization diversity for improved-performance circularly polarized multiple-input-multiple-output ultra-wideband antenna
    • Ubaid Ullah
    • Ismail Mabrouk
    • Sławomir Kozieł
    • Muath Al-hasan
    2020 Full text IEEE Access

    In this paper, spatial and polarization diversities are simultaneously implemented in an ultra-wideband (UWB) multiple-input-multiple-output (MIMO) antenna to reduce the correlation between the parallel-placed radiators. The keystone of the antenna is systematically modified coplanar ground planes that enable excitation of circular polarization (CP). To realize one sense of circular polarization as well as ultra-wideband operation, an extended rectangular slot is etched on the left-hand-side of the coplanar waveguide (CPW) feed. This is combined with the asymmetrical ground plane geometry on the right-hand-side of the feeding line. The current flowing on the slotted ground plane forms a quasi-loop and generates CP, whereas the combination of the vertical current on the feedline and the horizontal current on the asymmetric ground plane adds to the axial ratio (AR) bandwidth. To implement the MIMO design with polarization and spatial diversity, the position of the coplanar ground planes is switched with respect to the feedline, and placed in a parallel formation with the edge-to-edge distance of 0.29λ0 . All geometrical parameters are optimized at the full-wave level of description before prototyping and experimental characterization. Simulation and measured results indicate that the proposed MIMO antenna features approximately 82% impedance bandwidth from 2.9 GHz to 7.1 GHz and 68.5% (3.1 GHz- 6.35 GHz) AR bandwidth. Moreover, the peak envelop correlation coefficient (ECC) is below 0.003, which corresponds to almost no correlation between the radiators. The antenna can be operated with either bidirectional or unidirectional characteristics, covering multiple commercial application bands including WLAN and WiMax.

  • Implementation Of The Innovative Radiolocalization System VCS-MLAT (Voice Communication System Multilateration)
    • Szymon Wiszniewski
    • Olga Błaszkiewicz
    • Alicja Olejniczak
    • Jarosław Sadowski
    • Jacek Stefański
    2020

    In the article the concept of the radiolocalization subsystem of the VHF communication for aviation VCS-MLAT (Voice Communication System – Multilateration) is presented. The distributed localization system can estimate the position of the aircraft using the audio signals from aircraft transmitters in the VHF band (118-136 MHz). This paper shows initial verification of the possibility to use voice airband communication to estimate the position of the aircraft. Main assumptions of the project and the structure of the localization modules (ground receiver stations) are also presented.

  • Improved degradation of etodolac in the presence of core-shell ZnFe2O4/SiO2/TiO2 magnetic photocatalyst
    • Eryka Mrotek
    • Szymon Dudziak
    • Izabela Malinowska
    • Daniel Pelczarski
    • Zuzanna Ryżyńska
    • Anna Zielińska-Jurek
    2020 Full text SCIENCE OF THE TOTAL ENVIRONMENT

    In the present study, susceptibility to photocatalytic degradation of etodolac, 1,8-diethyl-1,3,4,9 – tetrahydro pyran - [3,4-b] indole-1-acetic acid, which is a non-steroidal anti-inflammatory drug frequently detected in an aqueous environment, was for the first time investigated. The obtained p-type TiO2-based photocatalyst coupled with zinc ferrite nanoparticles in a core-shell structure improves the separation and recovery of nanosized TiO2 photocatalyst. The characterization of ZnFe2O4/SiO2/TiO2, including XRD, XPS, TEM, BET, DR/UV-Vis, impedance spectroscopy and photocatalytic analysis, showed that magnetic photocatalyst containing anatase phase revealed markedly improved etodolac decomposition and mineralization measured as TOC removal compared to photolysis reaction. The effect of irradiation and pH range on photocatalytic decomposition of etodolac was studied. The most efficient degradation of etodolac was observed under simulated solar light for a core-shell ZnFe2O4/SiO2/TiO2 magnetic photocatalyst at pH above 4 (pKa=4.7) and below 7. The irradiation of etodolac solution in a broader light range revealed a synergetic effect on its photodegradation performance. After only 20 min of degradation, about 100% of etodolac was degraded. Based on the photocatalytic analysis in the presence of scavengers and HPLC analysis, the transformation intermediates and possible photodegradation pathways of etodolac were studied. It was found that ∙O2- attack on C2-C3 bond inside pyrrole ring results mostly in the hydroxylation of the molecule, which next undergoes CH2COOH detachment to give 1,9-diethyl-3,4-dihydro-pyrano[3,4-b]indol-4a-ol. The obtained compound should further undergo subsequent hydropyran and pyrrole ring breaking to give a family of benzene derivatives.

  • Improved model of isothermal and incompressible fluid flow in pipelines versus the Darcy–Weisbach equation and the issue of friction factor
    • Zdzisław Kowalczuk
    • Marek Tatara
    2020 Full text JOURNAL OF FLUID MECHANICS

    In this article, we consider the modelling of stationary incompressible and isothermal one-dimensional fluid flow through a long pipeline. The approximation of the average pressure in the developed model by the arithmetic mean of inlet and outlet pressures leads to the known empirical Darcy–Weisbach equation. Most importantly, we also present another improved approach that is more accurate because the average pressure is estimated by integrating the pressure along the pipeline. Through appropriate transformation, we show the difference between the Darcy–Weisbach equation and the improved model that should be treated as a Darcy–Weisbach model error, in multiplicative and additive form. This error increases when the overall pressure drop increases. This symptomatic phenomenon is discussed in detail. In addition, we also consider four methods of estimating the coefficient of friction, assess the impact of pressure difference on the estimated average flow velocity and, based on experimental data, we show the usefulness of new proposals in various applications.

  • Improved-Efficacy Optimization of Compact Microwave Passives by Means of Frequency-Related Regularization
    • Sławomir Kozieł
    • Anna Pietrenko-Dąbrowska
    • Hasan Alhasan
    2020 Full text IEEE Access

    Electromagnetic (EM)-driven optimization is an important part of microwave design, especially for miniaturized components where the cross-coupling effects in tightly arranged layouts make traditional (e.g., equivalent network) representations grossly inaccurate. Efficient parameter tuning requires reasonably good initial designs, which are difficult to be rendered for newly developed structures or when re-design for different operating conditions or material parameters is required. If global search is needed, due to either the aforementioned issues or multi-modality of the objective function, the computational cost of the EM-driven design increases tremendously. This paper introduces a frequency-related regularization as a way of improving the efficacy of simulation-based design processes. Regularization is realized by enhancing the conventional (e.g., minimax) objective function using a dedicated penalty term that fosters the alignment of the circuit characteristics (e.g., the operating frequency or bandwidth) with the target values specified by the design requirement. This leads to smoothening of the objective function landscape, improves reliability of the optimization process, and reduces its computational cost as compared to the standard formulation. An added benefit is the increased immunity to poor initial designs and multi-modality issues. In particular, regularization can make local search routines sufficient in situations where global optimization would normally be necessary. The presented approach is validated using two miniaturized circuits, a rat-race and a branch line coupler. The numerical results demonstrate its superiority over conventional design problem formulations in terms of reliability of the optimization process.

  • Improvement of Performance Level of Steel Moment-Resisting Frames Using Tuned Mass Damper System
    • Masoud Dadkhah
    • Reza Kamgar
    • Heisam Heidarzadeh
    • Anna Jakubczyk-Gałczyńska
    • Robert Jankowski
    2020 Full text Applied Sciences-Basel

    In this paper, parameters of the tuned mass dampers are optimized to improve the performance level of steel structures during earthquakes. In this regard, a six-story steel frame is modeled using a concentrated plasticity method. Then, the optimum parameters of the Tuned Mass Damper (TMD) are determined by minimizing the maximum drift ratio of the stories. The performance level of the structure is also forced to be located in a safety zone. The incremental dynamic analysis is used to analyze the structural behavior under the influence of the artificial, near- and far-field earthquakes. The results of the investigation clearly show that the optimization of the TMD parameters, based on minimizing the drift ratio, reduces the structural displacement, and improves the seismic behavior of the structure based on Federal Emergency Management Agency (FEMA -356). Moreover, the values of base shear have been decreased for all studied records with peak ground acceleration smaller or equal to 0.5 g.

  • Improvement of ships seakeeping performance by application of the full-scale cfd simulations
    • Karol Niklas
    • Hanna Pruszko
    2020

    The ship’s fuel economy is increasingly important. The paper presents the effect of redesigning a case study ship for increasing seakeeping performance. Selected wave parameters reflect very difficult operational conditions existing on the North Sea and the Baltic Sea. The analyzed variants of a case study ship represent the latest developments of modern hull forms. The concepts similar to V-shaped bulbous bow, X-bow, X-aft, B-bow were adopted. Full-scale CFD simulations were performed to analyze the influence of innovative hull forms on the added resistance, heave and pitch motions for head waves and two vessel speeds. It was found that with the use of Full-scale CFD simulations it is possible to capture phenomena that cause ship’s non-linear behavior. The calculated relation between added resistance and ships’ vertical motions was opposite to linear strip theory. It proves that the results obtained by linear strip theory method and the CFD can differ significantly.

  • Improvement of subsoil and railway substructure by explosive means.
    • Eligiusz Mieloszyk
    • Anita Milewska
    • Mariusz Wyroślak
    2020

    Quick and effective method of subsoil and railway substructure improvement by using explosive means (registered trade name: microblasting) allowes design and construct railways on lowered bearing soils (i.e. wetlands, marshlands, industrial by-products, municipal wastes, degraded antropogenic embankments). It is usefull and recommendable technology to construct new railways, modernization or maintenance and repairing of old ones (often associated with modernization). Properly improved subsoil and railway substructure is a warranty of reliability for railways. It increase vitality and security of rail traffic.

  • Improving Objective Speech Quality Indicators in Noise Conditions
    • Krzysztof Kąkol
    • Grazina Korvel
    • Bożena Kostek
    2020

    This work aims at modifying speech signal samples and test them with objective speech quality indicators after mixing the original signals with noise or with an interfering signal. Modifications that are applied to the signal are related to the Lombard speech characteristics, i.e., pitch shifting, utterance duration changes, vocal tract scaling, manipulation of formants. A set of words and sentences in Polish, recorded in silence, as well as in the presence of interfering signals, i.e., pink noise and the so-called babble speech, also referred to as the “cocktail-party” effect is utilized. Speech samples were then processed and measured utilizing objective indicators to check whether modifications applied to the signal in the presence of noise increased values of the speech quality index, i.e., PESQ (Perceptual Evaluation of Speech Quality) standard.

  • Improving the Accuracy of Automatic Reconstruction of 3D Complex Buildings Models from Airborne Lidar Point Clouds
    • Marek Kulawiak
    • Zbigniew Łubniewski
    2020 Full text Remote Sensing

    Due to high requirements of variety of 3D spatial data applications with respect to data amount and quality, automatized, effcient and reliable data acquisition and preprocessing methods are needed. The use of photogrammetry techniques—as well as the light detection and ranging (LiDAR) automatic scanners—are among attractive solutions. However, measurement data are in the form of unorganized point clouds, usually requiring transformation to higher order 3D models based on polygons or polyhedral surfaces, which is not a trivial process. The study presents a newly developed algorithm for correcting 3D point cloud data from airborne LiDAR surveys of regular 3D buildings. The proposed approach assumes the application of a sequence of operations resulting in 3D rasterization, i.e., creation and processing of a 3D regular grid representation of an object, prior to applying a regular Poisson surface reconstruction method. In order to verify the accuracy and quality of reconstructed objects for quantitative comparison with the obtained 3D models, high-quality ground truth models were used in the form of the meshes constructed from photogrammetric measurements and manually made using buildings architectural plans. The presented results show that applying the proposed algorithm positively influences the quality of the results and can be used in combination with existing surface reconstruction methods in order to generate more detailed 3D models from LiDAR scanning.

  • Improving the Performance of a Graphite Foil/Polyaniline Electrode Material by a Thin PEDOT:PSS Layer for Application in Flexible, High Power Supercapacitors
    • Zuzanna Zarach
    • Konrad Trzciński
    • Marcin Łapiński
    • Anna Lisowska-Oleksiak
    • Mariusz Szkoda
    2020 Full text Materials

    In this study, we present a novel strategy for enhancing polyaniline stability and thus obtaining an electrode material with practical application in supercapacitors. A promising (graphite foil/polyaniline/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) GF/PANI/PEDOT:PSS) electrode material was characterized and used in the construction of a symmetric supercapacitor that provides an outstanding high power density. For this purpose, the electropolymerization of PANI was carried out on a graphite foil and then a thin protective layer of PEDOT:PSS was deposited. The presence of the nanometer PEDOT:PSS layer made it possible to widen the electroactivity potential range of the electrode material. Moreover, the synergy between materials positively affected the amount of accumulated charge, and thus the thin PEDOT:PSS layer contributed to enhancing the specific capacity of the electrode material. The electrochemical performance of the GF/PANI/PEDOT:PSS electrode, as well as the symmetrical supercapacitor, was investigated by cyclic voltammetry and galvanostatic charge/discharge cycles in 1 M H2SO4 at room temperature. The fabricated electrode material shows a high specific capacitance (Csp) of 557.4 Fg−1 and areal capacitance (Careal) of 2600 mF·cm−2 in 1 M H2SO4 at a current density of 200 mA·cm−2 (~4 A·g−1). The supercapacitor performance was studied and the results show that a thin PEDOT:PSS layer enables cycling stability improvement of the device from 54% to 67% after 10,000 cycles, and provides a high specific capacity (159.8 F·g−1) and a maximum specific power (18,043 W·kg−1) for practical applications.

  • Improving the Performance of Ontological Querying by using a Contextual Approach
    • Wojciech Waloszek
    • Aleksander Waloszek
    2020 Full text Procedia Computer Science

    In the paper we present the results of experiment we performed to determine whether a contextual approach may be used to increase the performance of querying a knowledge base. For the experiments we have used a unique setting where we put much effort in developing a contextual and a non-contextual ontology which are as much close counterparts as possible. To achieve this we created a contextual version of a non-contextual ontology and reformulated the set of competency questions to reflect the contextual structure of the newly created knowledge base. The results of the experiment strongly suggest that using contexts might be advantageous for improving performance, and also show the further ways of development of the approach.

  • Improving the procedure of probabilistic load testing design of typical bridges based on structural response similarities
    • Piotr Owerko
    • Karol Winkelmann
    2020 Full text Archives of Civil Engineering

    This paper concerns load testing of typical bridge structures performed prior to operation. In-situ tests of a two-span post-tensioned bridge loaded with three vehicles of 38-ton mass each formed the input of this study. On the basis of the results of these measurements, an advanced FEM model of the structure was developed for which the sensitivity analysis was performed for chosen uncertainty sources. Three uncorrelated random variables representing material uncertainties, imperfections of positioning, and total mass of loading vehicles were indicated. Afterward, two alternative FE models were created based on a fully parametrized geometry of the bridge, differing by a chosen global parameter – the skew angle of the structure. All three solid models were subjected to probabilistic analyses with the use of the second-order Response Surface Method in order to define the features of the structural response of the models. It was observed that both the ranges of expected deflections and their corresponding mean values decreased with an increase in the skewness of the bridge models. Meanwhile, the coefficient of variation and the relative difference between the mean value and boundary quantiles of the ranges remain insensitive to the changes in the skew angle. Owing to this, a procedure was formulated to simplify the process of load testing design of typical bridges differing by a chosen global parameter. The procedure allows - if certain conditions are fulfilled - to perform probabilistic calculations only once and use the indicated probabilistic parameters in the design of other bridges for which calculations can be performed deterministically.

  • Improving the Quality of Magnetic Signature Reproduction by Increasing Flexibility of Multi-Dipole Model Structure and Enriching Measurement Information
    • Jarosław Tarnawski
    • Adam Cichocki
    • Tomasz Rutkowski
    • Krystian Buszman
    • Mirosław Wołoszyn
    2020 Full text IEEE Access

    The paper presents the construction of a multi-dipole model that allows reproducing magneticsignatures of ferromagnetic objects. The virtual object used in the paper is an ellipsoid, which is the sourceof synthetic data. To make the situation more realistic, noise is added to the synthetic data. Two significantimprovements compared to previous work are presented. Three-axial magnetometers are introduced insteadof uniaxial magnetometers. However, a more important change is the modification of the model structurethat allows placing dipoles on the entire plane, e.g. object’s deck. The multi-dipole model consists of ana priori assumed number of permanent and induced single-dipole models. Each single dipole is described bythree magnetic moments and, depending on the applied approach, one or two dipole position parameters. Thenon-linear least-squares optimization method is used to determine model parameters. To assess the qualityof magnetic signature reproduction, qualitative and quantitative forms are used. The final quality assessmentis based on differences between the reference fields and the fields determined from the multi-dipole model.The applied modifications bring significant improvement, however, only their combined application allowsto restore magnetic signatures with good quality for directions other than for which the data were available.

  • Improving the Survivability of Carrier Networks to Large-Scale Disasters
    • Amaro de Sousa
    • Jacek Rak
    • Fábio Barbosa
    • Dorabella Santos
    • Deepak Mehta
    2020

    This chapter is dedicated to the description of methods aiming to improve the survivability of carrier networks to large-scale disasters. First, a disaster classification and associated risk analysis is described, and the disaster-aware submarine fibre-optic cable deployment is addressed aiming to minimize the expected costs in case of natural disasters. Then, the chapter addresses the improvement of the network connectivity resilience to multiple node failures caused by malicious human activities. Two improvement methods are described aiming to minimize the connectivity impact of any set of node failures. One method is based on the appropriate selection of a set of network nodes to be made robust to node attacks. The other is a topology design method aiming to select the most appropriate set of links, within a given fibre budget, that provide the best resilience to multiple node failures. The latter method can also be applied to the upgrade task of a current network topology.

  • Imunofan—RDKVYR Peptide—Stimulates Skin Cell Proliferation and Promotes Tissue Repair
    • Justyna Sawicka
    • Maria Dzierżyńska
    • Anna Wardowska
    • Milena Deptuła
    • Piotr Rogujski
    • Paweł Sosnowski
    • Natalia Filipowicz
    • Alina Mieczkowska
    • Piotr Sass
    • Anna Pawlik
    • Aleksandra Hać
    • Adriana Schumacher
    • Magdalena Gucwa
    • Natalia Karska
    • Jolanta Kamińska
    • Rafał Płatek
    • Jarosław Mazuryk
    • Jacek Zieliński
    • Karolina Kondej
    • Piotr Młynarz
    • Piotr Mucha
    • Piotr Skowron
    • Łukasz Janus
    • Anna Herman-Antosiewicz
    • Paweł Sachadyn
    • Artur Czupryn
    • Arkadiusz Piotrowski
    • Michał Pikuła
    • Sylwia Rodziewicz-Motowidło
    2020 Full text MOLECULES

    Regeneration and wound healing are vital to tissue homeostasis and organism survival. One of the biggest challenges of today’s science and medicine is finding methods and factors to stimulate these processes in the human body. Effective solutions to promote regenerative responses will accelerate advances in tissue engineering, regenerative medicine, transplantology, and a number of other clinical specialties. In this study, we assessed the potential efficacy of a synthetic hexapeptide, RDKVYR, for the stimulation of tissue repair and wound healing. The hexapeptide is marketed under the name “Imunofan” (IM) as an immunostimulant. IM displayed stability in aqueous solutions, while in plasma it was rapidly bound by albumins. Structural analyses demonstrated the conformational flexibility of the peptide. Tests in human fibroblast and keratinocyte cell lines showed that IM exerted a statistically significant (p < 0.05) pro-proliferative activity (30–40% and 20–50% increase in proliferation of fibroblast and keratinocytes, respectively), revealed no cytotoxicity over a vast range of concentrations (p < 0.05), and had no allergic properties. IM was found to induce significant transcriptional responses, such as enhanced activity of genes involved in active DNA demethylation (p < 0.05) in fibroblasts and activation of genes involved in immune responses, migration, and chemotaxis in adipose-derived stem cells derived from surgery donors. Experiments in a model of ear pinna injury in mice indicated that IM moderately promoted tissue repair (8% in BALB/c and 36% in C57BL/6 in comparison to control).

  • In silico design of telomerase inhibitors.
    • Maciej Bagiński
    • Katarzyna Serbakowska
    2020 Full text DRUG DISCOVERY TODAY

    Telomerase is a reverse transcriptase enzyme involved in DNA synthesis at the end of linear chromosomes. Unlike in most other cells, telomerase is reactivated most cancerous cells and, therefore, has become a promising new anticancer target. Despite extensive research, direct telomerase inhibitors have yet not been introduced to the clinics because of the complexity of this enzyme. Structures of this protein from simple organisms and human homology models are currently available and have been used in structure-based drug design efforts to find potential inhibitors. Different is silico strategies have been applied and different chemical groups have been explored. Here, we provide an overview of recent discoveries.

  • In Vitro Biological Characterization of Silver-Doped Anodic Oxide Coating on Titanium
    • Oleksandr Oleshko
    • Iryna Liubchak
    • Yevheniia Husak
    • Viktoriia Korniienko
    • Aziza Yusupova
    • Tetiana Oleshko
    • Rafal Banasiuk
    • Marek Szkodo
    • Igor-Matros Taranets
    • Alicja Kazek-Kęsik
    • Wojciech Simka
    • Maksym Pogorielov
    2020 Full text Materials

    Despite the high biocompatibility and clinical effectiveness of Ti-based implants, surface functionalization (with complex osteointegrative/antibacterial strategies) is still required. To enhance the dental implant surface and to provide additional osteoinductive and antibacterial properties, plasma electrolytic oxidation of a pure Ti was performed using a nitrilotriacetic acid (NTA)-based Ag nanoparticles (AgNP)-loaded calcium–phosphate solution. Chemical and structural properties of the surface-modified titanium were assessed using scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) and contact angle measurement. A bacterial adhesion test and cell culture biocompatibility with collagen production were performed to evaluate biological effectiveness of the Ti after the plasma electrolytic process. The NTA-based calcium– phosphate solution with Ag nanoparticles (AgNPs) can provide formation of a thick, porous plasma electrolytic oxidation (PEO) layer enriched in silver oxide. Voltage elevation leads to increased porosity and a hydrophilic nature of the newly formed ceramic coating. The silver-enriched PEO layer exhibits an effective antibacterial effect with high biocompatibility and increased collagen production that could be an effective complex strategy for dental and orthopedic implant development.

  • In Vitro Studies on Nanoporous, Nanotubular and Nanosponge-Like Titania Coatings, with the Use of Adipose-Derived Stem Cells
    • Michalina Ehlert
    • Aleksandra Radtke
    • Tomasz Jędrzejewski
    • Katarzyna Roszek
    • Michał Bartmański
    • Piotr Piszczek
    2020 Full text Materials

    In vitro biological research on a group of amorphous titania coatings of different nanoarchitectures (nanoporous, nanotubular, and nanosponge-like) produced on the surface of Ti6Al4V alloy samples have been carried out, aimed at assessing their ability to interact with adipose-derived mesenchymal stem cells (ADSCs) and affect their activity. The attention has been drawn to the influence of surface coating architecture and its physicochemical properties on the ADSCs proliferation. Moreover, in vitro co-cultures: (1) fibroblasts cell line L929/ADSCs and (2) osteoblasts cell line MG-63/ADSCs on nanoporous, nanotubular and nanosponge-like TiO2 coatings have been studied. This allowed for evaluating the impact of the surface properties, especially roughness and wettability, on the creation of the beneficial microenvironment for co-cultures and/or enhancing differentiation potential of stem cells. Obtained results showed that the nanoporous surface is favorable for ADSCs, has great biointegrative properties, and supports the growth of co-cultures with MG-63 osteoblasts and L929 fibroblasts. Additionally, the number of osteoblasts seeded and cultured with ADSCs on TNT5 surface raised after 72-h culture almost twice when compared with the unmodified scaffold and by 30% when compared with MG-63 cells growing alone. The alkaline phosphatase activity of MG-63 osteoblasts co-cultured with ADSCs increased, that indirectly confirmed our assumptions that TNT-modified scaffolds create the osteogenic niche and enhance osteogenic potential of ADSCs.

  • In vivo performance of intraperitoneal onlay mesh after ventral hernia repair
    • Izabela Lubowiecka
    • Agnieszka Tomaszewska
    • Katarzyna Szepietowska
    • Czesław Szymczak
    • Maciej Śmietański
    2020 Full text CLINICAL BIOMECHANICS

    Background: Ventral hernia repair needs to be improved since recurrence, postoperative pain and other complications are still reported in many patients. The behavior of implants in vivo is not sufficiently understood to design a surgical mesh mechanically compatible with the human abdominal wall. Methods: This analysis was based on radiological pictures of patients who underwent laparoscopic ventral hernia repair. The pictures show the trunk of the patient at rest in a standing position and under side bending. The change in the distance between different tacks due to trunk movement was analyzed, which allowed us to determine the in vivo elongation of the mesh incorporated into the abdominal wall. Findings: The relative elongations of the surgical mesh varied from a few percent to greater than 100% in two cases. The median of the median relative elongations obtained for all patients is 9.5%, and the median of the maximum relative elongations for all patients is 32.6%. The maximum elongation occurs between tacks that are next to each other. Trunk movement causes implant deformation, and this study provides quantitative information regarding changes in the distance between fasteners. Interpretation: The physiological movement of the human abdomen must be regarded as a very important factor in mesh deformation and should be considered in surgical practice to reduce the hernia recurrence rate and postoperative pain.

  • In vivoevaluation of the CB1allosteric modulator LDK1258 reveals CB1-receptor independent behavioral effects
    • Teresa Olszewska
    • Mustafa Mohammed
    • Giulia Donvito
    • Lauren Moncayo
    • Amelia Swafford
    • Justin Poklis
    • Ralph Grauer
    • Bogna Ignatowska-Jankowska
    • Debra A. Kendall
    • Dai Lu
    • Aron H. Lichtman
    2020 PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR

    In the present study, we examined whether LDK1258, which produces strong CB1receptor allosteric effects ininvitroassays, would elicitin vivoeffects consistent with allosteric activity. In initial studies, LDK1258 reducedfood consumption and elicited delayed antinociceptive effects in the chronic constrictive injury of the sciaticnerve (CCI) model of neuropathic pain, which unexpectedly emerged 4 h post-injection. UPLC-MS/MS analysisquantified significant levels of LDK1258 in both blood and brain tissue at 30 min post-administration thatremained stable up to 4 h. The observation that LDK1258 also produced respective antinociceptive and anorecticeffects in rimonabant-treated wild type mice and CB1(−/−) mice suggests an off-target mechanism of action.Likewise, LDK1258 produced a partial array of common cannabimimetic effects in the tetrad assay, which werenot CB1receptor mediated. Additionally, LDK1258 did not substitute for the CB1receptor orthosteric agonistsCP55,940 or anandamide in the drug discrimination paradigm. In otherinvivoassays sensitive to CB1receptorallosteric modulators, LDK1258 failed to shift the dose-response curves of either CP55,940 or anandamide inproducing thermal antinociception, catalepsy, or hypothermia, and did not alter the generalization curve ofeither drug in the drug discrimination assay. Thus, this battery of tests yielded results demonstrating thatLDK1258 produces antinociceptive effects in the CCI model of neuropathic pain, anorectic effects, and otherinvivopharmacological effects in a manner inconsistent with CB1receptor allosterism. More generally, this studyoffers a straightforward screening assay to determine whether newly synthesized CB1receptor allosteric mod-ulators translate to the whole animal.

  • Including the Dark Side of Entrepreneurship in the Entrepreneurship Education
    • Paweł Ziemiański
    • Jakub Golik
    2020 Full text Education Sciences

    Pursuing an entrepreneurial career is often rewarding in terms of both economic and psychological outcomes. However, becoming an entrepreneur also has its darker side that affects professional and personal life. Meanwhile, the positivity bias is prevalent in entrepreneurial education and research. It is recognized as emphasizing the advantages of becoming an entrepreneur and giving considerably less attention to potential downsides. Based on the theoretical model of met expectations, it is proposed that building an accurate and balanced image of the entrepreneurial career is crucial to help students prepare to pursue it successfully. Using data from SEAS (Survey on Entrepreneurial Attitudes of Students) Project, authors quantitatively test the perception of the severity of negative aspects of entrepreneurship among 513 business students from northern Poland. Further, the results of 16 semi-structured qualitative interviews conducted with mature and experienced entrepreneurs from the same region are presented. They are focused on the entrepreneurs’ perspective on the experienced dark sides and reveal employed coping strategies. A call is made to include these findings in designing university entrepreneurship programs by eliciting the awareness of the existence of the dark sides and indicating the means of their attenuation.

  • Incomplete Cross-Bonding in the MV Line. Experience from the Operation of MV Single Cable Lines
    • Krzysztof Dobrzyński
    • Zbigniew Lubośny
    • Jacek Klucznik
    • Janusz Grala
    • Dominik Falkowski
    2020 Full text ENERGIES

    Cable lines are one of the basic components of power systems. Medium and high voltage cables mainly comprise a metallic sheath, which is concentric to the main core conductor. There are several operating schemes of such cable lines, which differ in the place of earthing of sheaths and the possible use of the sheaths and/or conductors crossing. The sheaths cross-bonding is typically done in two places of one cable line section, and it allows to reduce power losses. Nevertheless, the use of incomplete sheaths crossing—only in one place on cable route may have economic justification. The paper presents an incomplete sheaths cross-bonding analysis of an existing medium voltage cable line. The results obtained by the mathematical model are validated by measurements taken on 30 October 2019 on an existing cable line. Measurements recorded on a real object for various systems of crossing sheaths are presented. The influence of incorrect sheaths crossing on the measured quantities was shown. In addition, the risk of excess voltage on the sheaths during short-circuits has been verified using a mathematical model.

  • Increasing the Geometrical and Interpretation Quality of Unmanned Aerial Vehicle Photogrammetry Products Using Super-Resolution Algorithms
    • Paweł Burdziakowski
    2020 Full text Remote Sensing

    Unmanned aerial vehicles (UAVs) have now become very popular in photogrammetric and remote-sensing applications. Every day, these vehicles are used in new applications, new terrains, and new tasks, facing new problems. One of these problems is connected with flight altitude and the determined ground sample distance in a specific area, especially within cities and industrial and construction areas. The problem is that a safe flight altitude and camera parameters do not meet the required or demanded ground sampling distance or the geometrical and texture quality. In the cases where the flight level cannot be reduced and there is no technical ability to change the UAV camera or lens, the author proposes the use of a super-resolution algorithm for enhancing images acquired by UAVs and, consequently, increase the geometrical and interpretation quality of the final photogrammetric product. The main study objective was to utilize super-resolution (SR) algorithms to improve the geometric and interpretative quality of the final photogrammetric product, assess its impact on the accuracy of the photogrammetric processing and on the traditional digital photogrammetry workflow. The research concept assumes a comparative analysis of photogrammetric products obtained on the basis of data collected from small, commercial UAVs and products obtained from the same data but additionally processed by the super-resolution algorithm. As the study concludes, the photogrammetric products that are created as a result of the algorithms' operation on high-altitude images show a comparable quality to the reference products from low altitudes and, in some cases, even improve their quality.

  • Increasing the lifetime of engineering structures through the use of composite laggings
    • Eligiusz Mieloszyk
    • Anita Milewska
    • Marcin Abramski
    2020

    The use of composite laggings prevents concrete (chemical and biological) corrosion. Columns coated with composite or reinforced composite are more resistant to negative environmental impact on concrete or steel. The mechanical properties of the reinforced casing also cause that these types of columns are more resistant to lateral forces. The applied casing limits carbonization of concrete and cyclical freezing and thawing with penetrating water, and thus increases the lifespan of columns exposed to water. Laboratory tests were carried out regarding the short-time load-carrying capacity of columns in a composite laggings.

  • Industry 4.0 Implementation Challenges in Manufacturing Industries: an Interpretive Structural Modelling Approach
    • Ahmad Reshad Bakhtari
    • Vineet Kumar
    • Mohammad Waris
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Full text Procedia Computer Science

    For the last few years, the fourth industrial revolution, known as Industry 4.0, has been a hot topic among academics. Industry 4.0 literature involves researches presenting studies related to its different aspects including challenges, opportunities, implementation and adoption. However, a detailed study of challenges and barriers towards the Industry 4.0 implementation in manufacturing industries is missing. Hence, this paper aims to study and analyze the Industry 4.0 implementation challenges in manufacturing industries based on the expert opinions and the Interpretive Structural Modelling (ISM). The ISM analysis investigates the challenges in a structural base, finds the relationships between these challenges and finally shows how challenges affect each other to uncover the root cause triggering the other challenges. The industrial practitioners and managers can then take advantage of this analysis to know which challenge acts as the main barrier towards Industry 4.0 implementation and to be focused first in order to reach a solution.

  • Indywidualne programy integracyjne dla uchodźców i cudzoziemców objętych ochroną uzupełniającą z państw poradzieckich w dobie przynależności Polski do Unii Europejskiej
    • Krystyna Gomółka
    2020

    Celem pracy jest analiza uwarunkowań i skali obejmowania indywidualnymi programami integracyjnymi obywateli państw poradzieckich, którym przyznawano status uchodźcy i ochronę uzupełniającą w Polsce w okresie od 2004 r. do 2018 r., tj. od przystąpienia przez Polskę do Unii Europejskiej. Omawiane są następujące zagadnienia: uwarunkowania formalno-prawne ochrony międzynarodowej w Polsce, zasady przyznawania indywidualnych programów integracyjnych, skala udziału obywateli państw poradzieckich objętych ochroną międzynarodową w programach integracyjnych na tle innych grup cudzoziemców. Zaprezentowano także ocenę skuteczności programów integracyjnych oferowanych uchodźcom w Polsce opartą na badaniach przeprowadzonych przez Beatę Samoraj i Mieczysława Bienieckiego. Z kolei ustalenia dokonane przez Sławomira Łodzińskiego i Jana Kruszyńskiego pozwoliły ujawnić oceny, jakie Polacy formułują pod adresem tych programów oraz pomocy przyznawanej cudzoziemcom.