2019 - Repozytorium publikacji - Politechnika Gdańska

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The influence of water and mineral oil on volumetric losses in the displacement pump for offshore and marine applications
- Paweł Śliwiński
2019 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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 Pełny tekst 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.
The overview of reactors used for the production of precipitated calcium carbonate via carbonation route
- Natalia Czaplicka
- Donata Konopacka-Łyskawa
2019 Pełny tekst Aparatura Badawcza i Dydaktyczna
Carbonation is one of the methods for the production of precipitated calcium carbonate (PCC) on the industrial scale. A gaseous CO2 is used as a reagent in this process. The hydrodynamic conditions gener-ated in the reactor affect the course of the process and the characteristics of the precipitated calcium carbonate particles. This paper discusses the construction of standard reactors and new proposed con-struction used for the synthesis of calcium carbonate and presents the effect of precipitation conditions in selected reactors on the characteristics of PCC particles.
The Performance of ASON/GMPLS Network with Hierarchical Control Plane Structure
- Sylwester Kaczmarek
- Magdalena Młynarczuk
2019
The paper regards the problem of ASON/GMPLS network performance with hierarchical control plane structure in condition of incomplete domain network information. The authors propose the hierarchical ASON/GMPLS control plane architecture, which fulfills the requirements of modern optical networks and allows to control the multidomain network with requirement quality of service. The authors examine the scalability and properties of hierarchical control plane structure in order to indicate which parameters have significant impact on required quality of service. The analysis is performed with simulation method by using OMNeT++ discrete-event simulator. Obtained results are compared with results for flat control plane architecture.
The possibility of estimating the height of the ionospheric inhomogeneities based on TEC variations maps obtained from dense GPS network
- Grzegorz Nykiel
- Yevgen M. Zanimonskiy
- Aleksander Koloskov
- Mariusz Figurski
2019 ADVANCES IN SPACE RESEARCH
A state of the ionosphere can be effectively studied using electromagnetic signals received from global navigation satellite systems (GNSS). Utilization of the dual frequency observations allows estimating values of the total electron content (TEC). They can be used for a number of scientific studies such as detection and monitoring of traveling ionospheric disturbances or plasma bubbles. Moreover, maps of TEC variations allow to classify ionospheric heterogeneities and to evaluate their parameters. However, most of the research describes ionospheric parameters only in 2D space and time. In this paper, we focus on the determination of the height of the ionospheric inhomogeneities. We used a dense network of GPS receivers to obtain the sequences of TEC variation maps for different heights of the ionospheric layer. For each satellite observed above 70 deg, we constructed separate sets of maps. For each ionospheric height, the crosscorrelation function between maps corresponding to different satellites was calculated. The biggest cross-correlation coefficient value determines the height of the ionospheric irregularities. This paper describes the methodology and the results obtained for a geomagnetic storm on St. Patrick’s Day in March 2013. We have found that in quiet geomagnetic conditions the ionospheric irregularities are localized predominantly within the interval 180–220 km close to the maximum of the ionospheric F2 layer. In disturbed conditions, the height of their localization was increased up to several hundreds of kilometers. These estimations correspond to the changes in the slab thickness of the ionosphere.
The potential of LC–MS technique in direct analysis of perfume content
- Dagmara Kempińska-Kupczyk
- Agata Kot-Wasik
2019 Pełny tekst MONATSHEFTE FUR CHEMIE
Perfumes are products that consist of a wide range of natural and synthetic compounds. Due to complex composition, the determination of their ingredients is a difficult task. Most of the perfume components are either volatile or semi-volatile; however, most of the attention has been paid to volatile ones, and thus, gas chromatography or electronic noses are generally used. Nevertheless, in this study, liquid chromatography coupled with mass spectrometry has been applied for direct perfume analysis. Four samples of different best-selling perfumes (two men’s and two women’s fragrances) and their counterfeits were taken under consideration. The identification of their ingredients was performed by combining obtained results with information available in on-line databases. Compounds specific to essential oils and carrier oils, antioxidants and dyes were generally detected in both types of samples, whereas components of the fragrance of animal origin were only found in brand-name perfumes. On the other hand, counterfeits contained more types of polymer emulsifiers. Therefore, based on the results obtained, it can be concluded that liquid chromatography coupled with very sensitive detection technique can be used as a complementary approach to analyses performed with gas chromatography. Moreover, this technique offers the possibility to determine compounds that have low thermostability.
The potential of urban agriculture in the revitalisation of a metropolis
- Gabriela Maria Rembarz
2019
In Poland, the topic addressing urban areas of agricultural production and gardening activity is still viewed in two main blocks: 1) a shift of the urbanized zone’s boundaries, causing dispersion of suburban buildings as well as creates conflict zone between the residential area and the production and post-production zones; 2) a socially contentious issue of restructuring the inner-city complexes of former employee allotments. The article develops a conversation with the third block – urban gardening, understood as a revitalization tool – introducing a discussion on the city’s potentials, a perspective for alternative developmental scenarios within a metropolitan area. Threads of a metropolitan policy SMART have been collated with developmental potentials of the ‘slow life’ attitude and philosophy. The thesis was supported by the results of a study-research project titled: “SlowSmartOrunia: SlowLife in SmartCity”, carried out in the form of urban mentoring. Metropolization in Poland is plane of urban debate which revises the region-city-village relation. Urban agriculture has been the password triggering revision of the current modernization and development paradigm. The paste 25 years of the organizational and spatial changes implies the urban community’s growing interest in the SLOW mainstream. It combines unexpired Polish tradition with a new trends of western metropolises. Redefinition of the developmental targets and the methods, striving to reduce stress resulting from accelerations in technological and economic development. The need to maintain a secure sustainability in social development, responsible for the so-called urban resilient, that is, flexible resistance to the changes in developmental conditions. Smart City, while improving communication between the residents, should open developmental channels of new forms of codecision-making (creative planning and governance) and co-responsibility adequate to the contemporary pace and lifestyle. Mobilization of the city’s newly developed endogenic potential is meant to increase all the parameters hidden under the term ‘sustainable development’. Alternative strategies implemented in order to strengthen the social and cultural capital, here, gain special importance. Urban forms of plant cultivation, as tools for strengthening communities, are perceived as the symbol of change.
The preferable ways of decision-making in IT teams
- Beata Krawczyk-Bryłka
- Henryk Krawczyk
2019 Pełny tekst Decision Making in Manufacturing and Services
Software development team collaboration requires various decisions regarding essential aspects of a project’s progress. General and particular decision-making models are considered, and their main aspects such as team types, problem solving categories, and decision-making ways are analyzed. The research concerns representative groups of IT specialists and their preferences in decision-making are investigated. Four possible cases were tested: hierarchical choice (by leader) team members’ choice (team consensus or voting) and external expert impact. It allows one to show some differences in the behaviors of both traditional and virtual teams.
The principles of arturbain.fr for teaching sustainable urban design
- Izabela Burda
- Małgorzata Dymnicka
2019 Pełny tekst World Transactions on Engineering and Technology Education
The article is an attempt to show how important it is in the contemporary education of architecture students to use an ordered repertoire of principles and concepts of a universal nature, at the same time, pointing to the new directions of solutions and answers to the problems of the 21st century. This task is implemented by the French Association L'Arturbain dans les Territoires. It is accompanied by an idea consisting in observing a few basic principles in urban planning: learn to look, learn to get to know vocabulary, learn to cultivate memory, learn to work in a multi-disciplinary team, learn to communicate. Adopting an attitude thus defined towards the built environment implies undertaking specific actions for the recovery of public space, the restoration of landscape diversity, of socio-cultural identity, and the protection of the natural environment.
The Production Possibility of the Antimicrobial Filaments by Co-Extrusion of the PLA Pellet with Chitosan Powder for FDM 3D Printing Technology
- Szymon Mania
- Jacek Ryl
- Jia-Rong Jinn
- Ya-Jane Wang
- Anna Michałowska
- Robert Tylingo
2019 Pełny tekst Polymers
The last decades have witnessed a major advancement and development in three-dimensional (3D) printing technology. In the future, the trend’s utilization of 3D printing is expected to play an important role in the biomedical field. This work presents co-extrusion of the polylactic acid (PLA), its derivatives (sPLA), and chitosan with the aim of achieving filaments for printing 3D objects, such as biomedical tools or implants. The physicochemical and antimicrobial properties were evaluated using SEM, FT-IR, DSC, instrumental mechanical test, and based on the ASTM E2149 standard, respectively. The addition of chitosan in the PLA and sPLA filaments increased their porosity and decreased density. The FT-IR analysis showed that PLA and chitosan only formed a physical mixture after extrusion. The addition of chitosan caused deterioration of the mechanical properties of filaments, especially elongation at break and Young’s modulus. The addition of chitosan to the filaments improved their ability to crystallize and provide their antimicrobial properties against Escherichia coli and Staphylococcus aureus.