Publications Repository - Gdańsk University of Technology

Page settings

polski
Publications Repository
Gdańsk University of Technology

Show publications from the year

Publications from the year 2019

Show all
  • The Influence of Microstructure on the Passive Layer Chemistry and Corrosion Resistance for Some Titanium-Based Alloys
    • Nader El-bagoury
    • Sameh Ahmed
    • Ola Ahmed Abu Ali
    • Shimaa El-hadad
    • Ahmed Fallatah
    • G.a.m. Mersai
    • Mohamed Ibrahim
    • Joanna Wysocka
    • Jacek Ryl
    • Rabah Boukherroub
    • Mohammed Amin
    2019 Full text Materials

    The effect of microstructure and chemistry on the kinetics of passive layer growth and passivity breakdown of some Ti-based alloys, namely Ti-6Al-4V, Ti-6Al-7Nb and TC21 alloys, was studied. The rate of pitting corrosion was evaluated using cyclic polarization measurements. Chronoamperometry was applied to assess the passive layer growth kinetics and breakdown. Microstructure influence on the uniform corrosion rate of these alloys was also investigated employing dynamic electrochemical impedance spectroscopy (DEIS). Corrosion studies were performed in 0.9% NaCl solution at 37 °C, and the obtained results were compared with ultrapure Ti (99.99%). The different phases of the microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Chemical composition and chemistry of the corroded surfaces were studied using X-ray photoelectron spectroscopy (XPS) analysis. For all studied alloys, the microstructure consisted of α matrix, which was strengthened by β phase. The highest and the lowest values of the β phase’s volume fraction were recorded for TC21 and Ti-Al-Nb alloys, respectively. The susceptibility of the investigated alloys toward pitting corrosion was enhanced following the sequence: Ti-6Al-7Nb < Ti-6Al-4V << TC21. Ti-6Al-7Nb alloy recorded the lowest pitting corrosion resistance (Rpit) among studied alloys, approaching that of pure Ti. The obvious changes in the microstructure of these alloys, together with XPS findings, were adopted to interpret the pronounced variation in the corrosion behavior of these materials

  • The Influence of PEG on Morphology of Polyurethane Tissue Scaffold
    • Justyna Kucińska-Lipka
    • Helena Janik
    • Agnieszka Sulowska
    • Agnieszka Haryńska
    • Paweł Szarlej
    • Sylwia Grabska-Zielińska
    2019

    In this study, polyurethanes (PU) were synthesized from oligomeric dihydroxy(etylene-butylene adipate), poly(ethylene glycol) (PEG), hexamethylene diisocyanate (HDI), 1,4-butanediol (BDO) as chain extender and stannous octoate as catalyst. PEG due to its hydrophilic character influences physical and chemical properties of PU. For testing were used PU having the following weigh contents of PEG: 0%, 7%, and 14%. Porous scaffolds were prepared by the method of solvent casting and particulate leaching. The materials were subjected to miscoscopic analysis. Porosity and pore morphology were evaluated. Based on the results from experimental data, it was found that PEG influences the pore's morphology of the obtained scaffold. The scaffold containing 7% wt. of PEG showed optimal properties for tissue engineering.

  • The influence of robotization on the reliability of the production process in the bakery industry
    • Radosław Drozd
    • Jan Piwnik
    2019 Aparatura Badawcza i Dydaktyczna

    This article presents a new concept of technological system reliability based on the analysis of the relationship of associations of elements of energy streams, matter, information, time and finance. The method of stream specification and the method of determining the reliability values of significant and supporting relationships are given. Relevant relationships between elements of system streams were defined as having one-time reliability value. Supportive relationships have a value between zero and one. Relevant relationships are determined based on research, experience and knowledge. Pss expresses the efficiency of the production process. Pss indicates how to optimize the process by increasing the number of relationships significant between the components of the system batch streams. The Pss concept was used in research into the production efficiency of bakery X operating within the MiMPBP group. System analysis of the bakery allows a significant increase in the bread baking process reliability after using robotization. The concept of Pss stream-system reliability can be used to analyze the efficiency of technological processes and optimization in any production processes. This requires a detailed system analysis of such processes

  • The influence of solution annealing temperature on the properties of Lean Duplex 2101 welded joints in tubes
    • Grzegorz Rogalski
    • Aleksandra Świerczyńska
    • Dariusz Fydrych
    • Michał Landowski
    2019 Full text Przegląd Spawalnictwa

    The article presents a technology of TIG longitudinal welding without filler material (142) of heat exchanger tubes made of Lean Duplex 2101. The results of studies on the effect of heat treatment (solution annealing) on tensile strength, plasticity, delta ferrite and the structure of smooth tubes are shown. It was found, that the change in solution annealing temperature across the tested range has an impact on mechanical properties of welded tubes and the most advantageous solution annealing temperature (1050 °C) was determined.

  • The influence of the carbon equivalent on the weldability of high-strength low-alloy steel in the water environment
    • Jacek Tomków
    • Michalina Tomków
    2019 Full text Przegląd Spawalnictwa

    From many years, the high strength low alloy steels are often used for offshore constructions. This constructions, due to the environment in which they work, require more frequent repairs than the constructions from the land. For economic reasons, repairs take place in the underwater conditions, however water significantly decreases the weldability of steel. The paper presents the results of the CTS weldability test for S460ML and S460 steels, which have a similar value of the yield point, but different carbon equivalent (CeMIS) values. The welded joints were cut into specimens, which were then subjected to Vickers HV10 hardness measurements. The experiment has shown that as the CeMIS value increases, the hardness in the heat affected zone (HAZ) of joints and in the weld metal increases.

  • The Influence of the Co-Dopant Dexamethasone Phosphate on the Electrodeposition Process and Drug-Release Properties of Polypyrrole-Salicylate on Iron
    • Karolina Cysewska
    • Jakub Karczewski
    • Piotr Jasiński
    2019 JOURNAL OF THE ELECTROCHEMICAL SOCIETY

    In this work, the influence of incorporation of two anti-inflammatory drugs dexamethasone phosphate and sodium salicylate on the electrodeposition process of polypyrrole (PPy) film on iron has been studied. The incorporation of the agents into PPy has been carried out in a one-step electropolymerization process on oxidizable iron. The role of each drug agent during the deposition process has been discussed. The morphological and redox properties of as-deposited PPy doped with salicylate only or with addition of differently concentrated dexamethasone phosphate have been examined. Moreover, a spontaneous (in literature called: self-powered) drug-release study of PPy on iron was investigated in a phosphate buffer saline solution at the body temperature by the UV-Vis spectrophotometry with the flow cell. The study showed that the addition of high molecular weight co-dopant into PPy influenced much the growth mechanism and final properties of the material. It had also a big impact on the drug release profile compared to a polymer doped only with one agent.

  • The influence of the place of residence on the behavior and transport preferences of the inhabitants of the agglomeration
    • Krzysztof Grzelec
    • Romanika Okraszewska
    2019 Full text Transport Economics and Logistics

    Transport behaviors and preferences have an impact on modal split, which is why they should form the basis for shaping the public transport offer. Achieving the goals of sustainable mobility requires taking into account differences in transport behavior and preferences characterizing residents from different areas of the agglomeration. Analyzing differences in behaviors and preferences, the possibilities and limitations resulting from the mass character of public transport services and the fact that the main determinant of the offer is the space determined by displacements in the source-target relation should be taken into account. This article identifies differences in transport behavior and preferences of residents based on the center and suburbs of the Gdańsk agglomeration. At the same time, a preliminary attempt was made to explain the causes of specific differences in residents’ behavior and transport preferences, taking into account the limited volume ofpublication. Theshare ofpublic transport intheimplementation of travel decreases with the distance of the area of residence from the center of the agglomeration. The increase in the share of rail transport in travel affects the increase in the importance of waiting time and the lack of change as a decisive factor in the selection of cars in trips. Transport preferences are strongly diversified in individual areas. Differences are noticeable even in the center areas constituting separate administrative units.

  • The influence of the welding environment on the properties of Tekken joints made from S355J2C+N steel
    • Jacek Tomków
    • Anna Janeczek
    2019 Full text Przegląd Spawalnictwa

    There are three main methods of underwater welding: dry, wet and intermediate between them, by using the local dry chamber. Due to low costs, the most common method is the wet welding with the use of covered electrodes. Water as a welding environment carries out a lot of problems. The first is limited visibility and instability of the welding arc. The biggest problem during underwater welding is high susceptibility to cold cracking, resulting from the increased diffusible hydrogen content in deposited metal and high stress values. In the work, Tekken joints from S355J2C+N steel were made in air and in water environment. The joints were subjected to non-destructive visual (VT) and penetrant (PT) tests. Then, macroscopic tests and hardness measurements were performed. The results confirm the literature reports that the water environment causes an increase in hardness in the heat affected zone (HAZ), which promotes the formation of cracks in welding joints.

  • The influence of water and mineral oil on volumetric losses in the displacement pump for offshore and marine applications
    • Paweł Śliwiński
    2019 Full text Polish Maritime Research

    In this paper volumetric losses in a positive displacement pump supplied with water and mineral oil are described and compared. The experimental tests were conducted using a prototype of a satellite pump (with a non-circular tooth working mechanism). In this paper the sources of volumetric losses in this pump are characterised. On this basis, a mathematical model of these losses has been presented. The results of the calculation of volumetric losses according to the model are compared with the results of the experiment. Experimental studies have shown that the volumetric losses in the water pump are even 3.2 times greater than the volumetric losses in the oil pump. It has been demonstrated that the mathematical model describing the volumetric losses both in the water pump and in the oil pump is quite well. It has been found that the results from the loaded pump simulation (at p=25MPa and ant n=1500rpm) differ from the results of the experiment by no more than 5% both for oil and water.

  • The interpretation of the parameters of the equation used for the extrapolation of apparent molar volumes of the non-electrolyte (solutes) to the infinite dilution
    • Jarosław Wawer
    • Joanna Krakowiak
    2019 JOURNAL OF MOLECULAR LIQUIDS

    The paper discusses how to interpret the parameters of the basic equation used for the extrapolation of the apparent molar volume of the solute to infinite dilution. The common misunderstandings and oversimplifications have been pointed out. We present the alternative ways of the data interpretation that can be used to eliminate these obvious but frequent mistakes.

  • The lethal effect of hydrotechnical concrete on freshwater Bivalvia
    • Barbara Wojtasik
    • Małgorzata Zbawicka
    • Lucyna Grabarczyk
    • Marzena Kurpińska
    2019 Full text Limnological Review

    Most hydrotechnical buildings under construction demand the concrete mixture to be set directly under water. The main reason for such a procedure is to limit the washing away of the the concrete binding mixture and to increase the efficiency of organisation of work so as to ensure continuity in concreting. The impact on the aquatic environment of recent developments in concrete technology and the use of new components has not yet been established . Natural pebble aggregate containing portland cement and fugacious siliceous ash as a binder was used to prepare BP concrete samples, while concrete marked LB was composed with lightweight aggregate and portland cement as a binder. The aim of this paper was to answer to the question whether hydrotechnical concrete of different compositions (BP and LB) and the technology of setting in a water habitat have any influence on the life condition of commonly occurring Dreissena polymorpha (Mollusca, Bivalvia). The lethal effect of two types of freshly hardening concrete was observed. In the case of LB concrete the lethal outcome for D. polymorpha could be the effect of a considerable increase of electrolytic conduction in the test cultivation. In the case of BP the parameters of electrolytic conductivity and pH did not exceed the values appearing in lakes. The possibility of the occurrence of toxic compounds of D. polymorpha, arising from the reaction of the aquatic / lake environment or the elution of some components should be taken into account. D. polymorpha serves as an indicator of toxicity in the aquatic environment and therefore can be used as a model organism in the analysis of the influence concrete on the natural environment. The results obtained in this study indicate the significant impact of modern chemical composition of concrete on the aquatic environment and the living organisms that cover it. They underline the need for research based on the hydrobiont reaction to the substances used in the natural environment.

  • The linkage between knowledge risk management and organizational performance
    • Susanne Durst
    • Christoph Hinteregger
    • Małgorzata Zięba
    2019 Full text JOURNAL OF BUSINESS RESEARCH

    The purpose of this study is to examine the effect of knowledge risk management (KRM) on organizational performance, with measures considered as “softer” measures of performance, i.e. innovativeness, responsiveness, sustainability, and agility. Data were collected using an online questionnaire sent to private and public orga- nizations located all over the world. The analysis and hypotheses testing were performed using structural equation modeling. The results showed that KRM positively affects organizational success, sustainability, growth, innovativeness, and agility, however, KRM does not show any positive effect on the responsiveness of organizations. The results can help managers and owners to a better understanding of the linkage between KRM and organizational performance. They could use the results to design their KRM practices accordingly. To the authors' best knowledge, this paper is the first empirical study that has investigated the relationship between KRM and organizational performance with a broad organization sample.

  • The Maslov index and the spectral flow—revisited
    • Marek Izydorek
    • Joanna Janczewska
    • Nils Waterstraat
    2019 Full text Fixed Point Theory and Applications

    We give an elementary proof of a celebrated theorem of Cappell, Lee and Miller which relates the Maslov index of a pair of paths of Lagrangian subspaces to the spectral flow of an associated path of self-adjoint first-order operators. We particularly pay attention to the continuity of the latter path of operators, where we consider the gap-metric on the set of all closed operators on a Hilbert space. Finally, we obtain from Cappell, Lee and Miller’s theorem a spectral flow formula for linear Hamiltonian systems which generalises a recent result of Hu and Portaluri.

  • The metabolic activity of denitrifying microorganisms accumulating polyphosphate in response to addition of fusel oil
    • Agnieszka Tuszyńska
    • Magdalena Kaszubowska
    • Przemysław Kowal
    • Slawomir Ciesielski
    • Jacek Mąkinia
    2019 Full text BIOPROCESS AND BIOSYSTEMS ENGINEERING

    The effect of distillery waste product (fusel oil) as an alternative external organic carbon source (EOCS) was investigated in terms of the metabolic properties of denitrifying polyphosphate accumulating organisms (DPAOs). Samples of the non-acclimated biomass were collected from a local full-scale wastewater treatment plant employing A2/O type bioreactors. The acclimated biomass was obtained after cultivation (with fusel oil added) in a bench-scale reactor with a process configuration similar to the full-scale bioreactor. Changes in the functional properties of the biomass were investigated by measuring the phosphate release/uptake rates (PRRs and PURs), and nitrate utilization rates (NURs) with fusel oil in anaerobic-anoxic batch tests. Furthermore, a validated extended Activated Sludge Model no 2d (ASM2d) was used as a supporting tool to analyze the experimental results and estimate the contribution of DPAOs to the overall denitrification. In the non-acclimated biomass with fusel oil, the PRRs, PURs and NURs were low and close to the rates obtained in a reference test without adding EOCS. With the acclimated biomass, the PUR and NUR increased significantly, i.e., 3.5 and 2.7 times, respectively. In the non-acclimated biomass, approximately 60.0 ± 3.6% and 20.0 ± 2.2% of the total NUR was attributed to the utilization of endogenous carbon and examined EOCS, respectively. The remaining portion (20% of the total NUR) was attributed to PHA utilization (linked to PO4-P uptake) by DPAOs. With the acclimated biomass, the contribution of the EOCS to the NUR increased to approximately 60%, while the contribution of the endogenous carbon source decreased accordingly. Very accurate predictions of PURs and NURs (R2 = 0.97–1.00) were obtained with the extended ASM2d. Based on model simulations, it was estimated that the activity of DPAOs and denitrifying ordinary heterotrophic organisms corresponded to approximately 20% and 80% of the total NUR, respectively.

  • The Method of Finding the Optimal Spindle Speed When Milling Flexible Details
    • Barbara Kowalska
    • Krzysztof Jan Kaliński
    2019

    The paper presents a new method of vibration reduction during milling of flexible details. The method consists in selecting the optimal spindle speed, based on the natural frequency of the workpiece. For this purpose, an original method was created, which is based on minimizing the work of cutting forces in the direction of the depth of cutting. The effectiveness of the method has been proved by comparing the RMS values of vibration displacements in the time-domain obtained during experimental research.

  • The methodology of design of axial clearances compensation unit in hydraulic satellite displacement machine and their experimental verification
    • Paweł Śliwiński
    2019 Full text Archives of Civil and Mechanical Engineering

    A new methodology of calculating the dimensions of the axial clearance compensation unit in the hydraulic satellite displacement machine is described in this paper. The methods of shaping the compensation unit were also proposed and described. These methods were used to calculate the geometrical dimensions of the compensation field in an innovative prototype of a satellite hydraulic motor. This motor is characterized by the fact that the body rotates. In other words, the planet (an inner element of the working mechanism) is stationary and the curvature (an external element of the working mechanism) is rotating. The inflow and outflow ports are located in the motor pin which replaces its shaft. The results of the analytical calculation of the compensation field geometrical dimensions were used in FEM calculations of the compensation plate deformation. The correctness of the design of axial clearance compensation unit has been verified experimentally. The experimental method consists in measuring leaks in the gaps of the working mechanism and measuring the torque at low constant speed of the motor case. The results of experimental test are also described in this paper. This way, it has been proven that the proposed new analytical methodology for the design of the axial clearance compensation unit in the hydraulic satellite displacement machine is correct.

  • The Morphology, Structure, Mechanical Properties and Biocompatibility of Nanotubular Titania Coatings before and after Autoclaving Process
    • Aleksandra Radtke
    • Michalina Ehlert
    • Tomasz Jędrzejewski
    • Michał Bartmański
    2019 Full text Journal of Clinical Medicine

    The autoclaving process is one of the sterilization procedures of implantable devices. Therefore, it is important to assess the impact of hot steam at high pressure on the morphology, structure, and properties of implants modified by nanocomposite coatings. In our works, we focused on studies on amorphous titania nanotubes produced by titanium alloy (Ti6Al4V) electrochemical oxidation in the potential range 5–60 V. Half of the samples were drying in argon stream at room temperature, and the second ones were drying additionally with the use of immersion in acetone and drying at 396 K. Samples were subjected to autoclaving and after sterilization they were structurally and morphologically characterized using Raman spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) and scanning electron microscopy (SEM). They were characterized in terms of wettability, mechanical properties, and biocompatibility. Obtained results proved that the autoclaving of amorphous titania nanotube coatings produced at lower potentials (5–15 V) does not affect their morphology and structure regardless of the drying method before autoclaving. Nanotubular coatings produced using higher potentials (20–60 V) require removal of adsorbed water particles from their surface. Otherwise, autoclaving leads to the destruction of the architecture of nanotubular coatings, which is associated with the changing of their mechanical and biointegration properties.

  • The Multiplatform Environment for Simulation and Features Estimation of Mixed-Signal Devices
    • Krystyna Noga
    • Beata Pałczyńska
    • Romuald Maśnicki
    2019

    The use of simulation laboratories is gaining popularity in thedomains of engineering programs. However, the experience in teaching showsthat the simulation itself is not very effective in didactic processes. Teachingprocesses in thefield of specialist subjects, designed for students of technicaluniversities, should be based on direct operations performed by the student onreal devices. At the same time, at the later stages of didactic processes, moderncomputer tools and techniques that enable modeling, simulations and mea-surements of projected systems or devices cannot be omitted. The article pre-sents an example of applications of computer technology in the analysis ofsystem properties at the stage of their designing, commissioning and testing ofprototype properties. Based on the chosen hybrid system, in mixed analog-digital technology, the novel techniques of testing its functional properties werepresented. The multiplatform combined with graphical programming and sim-ulation software and hardware allows comparing a schematically captured cir-cuit with a prototype of the same design. The platform based on NI myDAQinstruments and the Multisim Circuit Design software is presented. To illustrateits capabilities, the generator of the sawtooth wave with a mixed analogue-digital structure was tested. The integration between NI Multisim and NImyDAQ makes possible to correlate real and simulated measurements in asingle interface. The possibility of presented techniques combined use allowsoptimizing the processes of designing, commissioning, testing and teaching theproperties of electronic circuits.

  • The Optimal Location of Ground-Based GNSS Augmentation Transceivers
    • Jacek Rapiński
    • Artur Janowski
    2019 Full text Geosciences

    Modern Global Navigation Satellite Systems (GNSS) allow for positioning with accuracies ranging from tens of meters to single millimeters depending on user requirements and available equipment. A major disadvantage of these systems is their unavailability or limited availability when the sky is obstructed. One solution is to use additional range measurements from ground-based nodes located in the vicinity of the receiver. The highest accuracy of distance measurement can be achieved using ultra wide band (UWB) or ZigBee phase shift measurement. The position of the additional transmitter must be carefully selected in order to obtain the optimal improvement in the dilution of precision (DOP), which reflects the improvement in the geometry of solution. The presented case study depicts a method for selecting the optimal location of a ground-based ranging source. It is based on a search of a minimum DOP value as a transmitter location function. The parameters of objective function are the elevation and azimuth of the transceiver. The solution was based on a limited-memory Broyden–Fletcher–Goldfarb–Shanno with Box constraints (L-BFGS-B) method and a numerical optimization algorithm for parameter value estimation. The presented approach allows for the selection of the optimal location of a ground-based source of ranging signals in GNSS processing from a geometry of solution point of view. This can be useful at the design stage of an augmentation network of ground-based transceivers. This article presents a theoretical basis and a case study presenting the selection of the optimal location of a ground-based ranging source.

  • The optimization of enzyme immobilization at Au-Ti nanotextured platform and its impact onto the response towards glucose in neutral media
    • Wiktoria Lipińska
    • Siuzdak Katarzyna
    • Jacek Ryl
    • Piotr Barski
    • Gerard Śliwiński
    • Katarzyna Grochowska
    2019 Materials Research Express

    The market of non-invasive glucose sensors is drastically growing due to increasing number of people suffering from diabetes. Therefore, there is a significant need for any improvement in the field of biosensors that can be used for monitoring glucose level in human body. In recent years the emphasis is put onto the modification of electrode material with enzymes possessing recognition centre specific towards particular molecules. In this work, the nanoscale Au-Ti heterostructures functionalized with glucose oxidase is reported. Au-Ti material is prepared by anodization of Ti foil, chemical etching, thin Au layer sputtering and finally thermal treatment under continuous regime. The formation of dimples as well as the single Au nanoparticle per each structure dimple was revealed by field emission scanning electron and atomic force microscopies. The surface of obtained material is modified with glucose oxidase enzyme by three immobilization methods: covalent bonding, adsorption and crosslinking leading to selection of the most optimized electrode preparation process. In order to confirm enzyme presence and to describe the chemical state of elements, x-ray photoelectron spectroscopy measurements were performed indicating the complete coverage of Au-Ti material by the enzyme layer. The obtained electrodes were tested in 0.1 M phosphate buffer saline with an addition of glucose using cyclic and differential pulse voltammetries. The determined linear range of 0.05–3.05 mM and detection limit of 7.61 μM satisfy the demands for glucose detection in human body fluids, for example interstitial fluid and sweat. Moreover, no impact onto the electrode response is observed for typical interfering species that is of key importance for further application.