2018 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2018

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The domination of ionic conductivity in tetragonal phase of the organometal halide perovskite CH3NH3PbI3-xClx
- Damian Głowienka
- Tadeusz Miruszewski
- Jędrzej Szmytkowski
2018 Full text SOLID STATE SCIENCES
Organometal trihalide perovskites have recently gained extreme attention due to their high solar energy conversion in photovoltaic cells. Here, we investigate the contribution of iodide ions to a total conductivity of the mixed lead halide perovskite CH3NH3PbI3−xClx with a use of the modified DC Hebb–Wagner polarization method. It has been identified that an ionic conductivity dominates in tetragonal phase which is associated with room temperature. The obtained activation energy for this type of hopping mechanism is equal to (0.87 ± 0.02) eV, which is in a good agreement with previous literature reports. The high contribution of ionic conductivity at room temperature might be a reason of the observed hysteresis in halide perovskite solar cells.
The Drop-in-Drop Encapsulation in Chitosan and Sodium Alginate as a Method of Prolonging the Quality of Linseed Oil
- Szymon Mania
- Robert Tylingo
- Anna Michałowska
2018 Full text Polymers
Nowadays, the encapsulation of sensitive products by various techniques has become popular as a promising preservation method. In particular, this applies to oils with a high content of unsaturated fatty acids and a high susceptibility to deterioration. This work presents the possibility of using a chitosan and sodium alginate in the form of a hydrogel membrane to protect food ingredients such as linseed oil, which is stored in an aquatic environment. The obtained results showed the high efficiency of the coaxial method encapsulation, which did not affect the quality of the oil measured after encapsulation. The greatest protective effect was observed in the linseed oil–chitosan membrane system, in which the primary and secondary oxidation products content were 88% and 32% lower than in the control sample, respectively. The smallest changes of the fatty acid profile, conjugated dienes, and trienes were observed in the chitosan capsules with linseed oil compared to the control sample.
The Dynamical Projectors Method Hydro and Electrodynamics
- Anna Perelomova
- Sergey Leble
2018
The dynamical projectors method proves to reduce a multicomponent problem to the simplest one-component problem with its solution determined by specific initial or boundary conditions. Its universality and application in many different physical problems make it particularly useful in hydrodynamics, electrodynamics, plasma physics, and boundary layer problems. A great variety of underlying mechanisms are included making this book useful for those working in wave theory, hydrodynamics, electromagnetism, and applications.
The Eastern Battery in Świnoujście, Poland - history and architecture of a Prussian coastal fort from the 19th century
- Arkadiusz Woźniakowski
2018
The article describes the history, architecture and development of the Eastern Battery (also known as the Gerhard Fort) – one of three remaining coastal forts in Świnoujście (former Swinemünde) located in northern Poland, by the Baltic Sea. The research is mostly based on historical cartographic material and architectural plans verified during field studies. This data served to create a digital model – one of the results of the study, as well as a research tool helping to detect and visualize transformations of the fort. Thanks to the rich archival collection and good preservation state of the object, it was possible to determine all its stages of construction and modernization between 1848 and 1905, which had not yet been included in contemporary literature. It appeared to be an outstanding example of how coastal fortifications developed, under the influence of new armament and construction materials, during the second half of ninetieth century. This knowledge completes the historiography of military architecture but can also be useful during the ongoing process of restauration of the fort, which serves as a museum and is a significant tourist attraction in the region.
THE EFFECT OF ALTERNATIVE CUTTER PATHS ON FLATNESS DEVIATIONS IN THE FACE MILLING OF ALUMINUM PLATE PARTS
- Michał Dobrzyński
- Daniel Chuchała
- Kazimierz Orłowski
2018 Full text Journal of Machine Engineering
In this paper the relationships between the alternative machining paths and flatness deviations of the aluminum plate part, were presented. The flatness tolerance of the main surface of the plate part has crucial meaning due to the assembly requirement of piezoelectric elements on the radiator. The aluminum bodies under investigation are the base part of the radiators with crimped feathers for the train industry. The surface of the aluminum plate part was milled using three different milling strategies: along of longer or shorter side of workpiece and at an angle of 45°. The aluminum bodies were machined on milling centre ecoMILL 70 DMG MORI. The flatness deviation measurements were carried out on the Coordinated Measuring Machine Altera 7.5.5 Nikon Metrology NV. These measurements were made during the manufacturing process of the radiator, namely after machining, however, before the process crimping of feathers. The results that were obtained enables the validation of assumed milling path strategies in connection of the subsequent machining and assembly processes.
The Effect of Full-Cell Impregnation of Pine Wood (Pinus sylvestris L.) on Changes in Electrical Resistance and on the Accuracy of Moisture Content Measurement Using Resistance Meters
- Aleksandra Konopka
- Jacek Barański
- Kazimierz Orłowski
- Karol Szymanowski
2018 Full text BIORESOURCES
The impact of the full-cell impregnation of pine wood was investigated with respect to changes in electrical resistance and the accuracy of moisture content measurement. This study compared the resistance of impregnated and untreated pine timber harvested from the northern part of Poland (Pomeranian region). The wood was impregnated by the vacuum-pressure method. The preservative (TANALITH E 3475) and coloring (TANATONE 3950) agents were based on copper salts. The results showed a dependence of wood resistance as a function of the moisture content. Impregnated and not treated wood samples were used. This result reflects the greater conductivity of the impregnate solution (based on copper salt) than the water. This phenomenon became more distinctive as moisture content value was above the Fiber Saturation Point (FSP).
The effect of full-cell impregnation of pine wood (Pinus Sylvestris L.) on the fine dust content during sawing on a frame sawing machine
- Kazimierz Orłowski
- Daniel Chuchała
- Ladislav Dzurenda
2018 Full text Trieskove a Beztrieskove Obrabanie Dreva
In this paper the results of the analysis of the effect of the impregnation treatment of pine wood on the granularity of sawdust from the sawing process on the frame sawing machine PRW 15M are presented. Granulometric analyses of chips from impregnated and unimpregnated pine wood implies that the impregnation of pine wood does not affect the size and structure of the sawdust produced. A major ≈ 95% share of the formed chips is the coarse and thick coarse fractions at a grain range of 125 μm to 2 mm. The slight difference is in the fraction of the fine fraction with a particle size of 32 - 125 μm. While the share of pine wood sawdust of unimpregnated wood is between 0.48 and 0.8%, and of the impregnated wood pine wood is 0.68 - 1.1%. This fact does not affect the efficiency of separation in fabric filters and the technological use of sawdust in the production of briquettes and pellets.
The effect of high molecular weight bio-based diamine derivative of dimerized fatty acids obtained from vegetable oils on the structure, morphology and selected properties of poly(ether-urethane-urea)s
- Marcin Włoch
- Janusz Datta
- Kamila Błażek
2018 Full text JOURNAL OF POLYMERS AND THE ENVIRONMENT
In this work, the effect of the high molecular weight bio-based diamine on the chemical structure and selected properties of poly(ether-urethane-urea)s has been investigated. The ether-urethane prepolymer was cured using 1,4-butanediol and/or bio-based diamine. Mentioned chain extenders were used separately or in the mixture, and their different molecular weight and chemical structure resulted in obtaining materials with diversified mechanical performence. The presence of specific chemical groups (i.e. urethane and urea groups) was confirmed by FTIR method. For the synthesized poly(ether-urethane-urea)s morphology and fracture mechanism, thermo-mechanical properties and mechanical properties were determined and discussed. Results confirmed that bio-based diamine acts as soft segments, and this is connected with changing of mechanical and thermo-mechanical properties of prepared partially bio-based poly(etherurethane-urea)s. The increasing content of bio-based diamine resulted in increasing of tensile modulus and decreasing of tensile strength and elongation at break, and this is resulted from chemical structure of biobaseddiamine (i.e. presence of aliphatic side chains).
The Effect of Long Term Service at Elevated Temperatures on Microstructure Degradation of Austenitic Reformer Tubes
- Jerzy Łabanowski
- Mateusz Jurkowski
- Michał Landowski
2018 Full text Advances in Materials Science
The paper analyses the relationship between an increase of the inner diameter of tubes made of Manaurite XM cast steel and transformations occurring in their microstructure due to long-lasting operation in methane reformer. Examinations included metallographic analysis with light microscope (LM), scanning electron microscope (SEM) and microanalysis of the chemical composition of precipitates (EDX). It was indicated that there is a relationship between the microstructure degradation ratio, morphology of the precipitates and an increase of the inner diameter of the tubes.
The effect of macro polymer fibres length and content on the fibre reinforced concrete
- Aleksandra Kuryłowicz-Cudowska
- Marzena Kurpińska
2018 Full text MATEC Web of Conferences
The paper presents studies of a ready-mix concrete containing polymer fibres of three different lengths: 24, 38 and 54 mm. The performed tests allowed to determine the effect of fibre volume fraction and length on the concrete strength. The basic parameters of concrete mixture (consistency, air content and bulk density) were identified. Fibre reinforced concrete belongs to a group of composite materials. The polymer fibres are applied in the concrete in structures where the reduction of shrinkage cracking as well as corrosion resistance and fire temperatures are required. It is widely known, that the cracking behaviour of concrete structures depends on flexural tensile strength of concrete. The addition of fibres significantly improves the tensile strength. The experimental study, including axial compressive strength and center-point loading flexural tensile strength, was carried out. The scope of the research was also expanded by the usage of a scanning microscope. The test results showed the effect of fibre length and fibre combinations on mechanical properties of concrete. The effect of the research is to formulate guidelines due to the quantity of macro polymer fibres. In general, appropriate fibre content brings a beneficial effect e.g. improves better workability of a concrete
THE EFFECT OF NOTCH DEPTH ON CTOD VALUES IN FRACTURE TESTS OF STRUCTURAL STEEL ELEMENTS
- Jakub Kowalski
- Janusz Kozak
2018 Full text Polish Maritime Research
In elements of steel structures working at low temperatures, there is a risk of appearance of brittle fracture. This risk is reduced through the use of certified materials having guaranteed strength at a given temperature. A method which is most frequently used to determine brittle fracture toughness is the Charpy impact test, preformed for a given temperature. For offshore structures intended to work in the arctic climat e, the certifying institutions more and more often require Crack Tip Opening Displacement (CTOD) tests instead of conventional impact tests, especially for steel and welded joints of more than 40 mm in thickness in the case of high-strength steel, and more than 50 mm for the remaining steels. The geometry of specimens and the test procedure are standardised; however, these standards provide some margin for specimen notch depth. The paper analyses the effect of notch depth difference, within the range permitted by the standards, on the recorded CTOD values of a given material. The analysis was performed via numerical modelling of destruction of specimens with different notch geometries and further verification of the obtained numerical results in laboratory tests. The calculations were carried out at the Academic Computer Centre in Gdansk.
The effect of numerical 2D and 3D FEM element modelling on strain and stress distributions at laser weld notches in steel sandwich type panels
- Karol Niklas
- Janusz Kozak
2018 Full text Polish Maritime Research
Like other means of transport, merchant ships face the problem of increasing requirements concerning the environment protection, which, among other issues, implies the reduction of fuel consumption by the ship. Here, the conventional approach which consists in making use of higher strength steels to decrease the mass of the ship hull can be complemented by the use of new steel structures of sandwich panel type. However, the lack of knowledge and experience concerning, among other issues, fatigue strength assessment of thin-walled sandwich structures makes their use limited. Untypical welds imply the need for individual approach to the fatigue analysis. The article presents the effect of numerical FEM modelling with the aid of two-dimensional (2D) and three-dimensional (3D) elements on the results of strain and stress distributions in the areas of toe and root notches of the analysed laser weld. The presented results of computer simulation reveal that modelling of strain and stress states in 2D (instead of full 3D) affects only the results in close vicinity of the notch, and the observed differences rapidly disappear at a distance of 0.05 mm from the bottom of the notch. The obtained results confirm the possibility of use of numerically effective 2D strain and stress state models for analysing the fatigue strength of laser weld according to local approach.
The Effect of Oxygenated Diesel-N-Butanol Fuel Blends on Combustion, Performance, and Exhaust Emissions of a Turbocharged CRDI Diesel Engine
- Gvidonas Labeckas
- Stasys Slavinskas
- Jacek Rudnicki
- Ryszard Zadrąg
2018 Full text Polish Maritime Research
The article deals with the effects made by using various n-butanol-diesel fuel blends on the combustion history, engine performance and exhaust emissions of a turbocharged four-stroke, four-cylinder, CRDI 1154HP (85 kW) diesel engine. At first, load characteristics were taken when running an engine with normal diesel fuel (DF) to have ‘baseline’ parameters at the two ranges of speed of 1800 and 2500 rpm. Four a fossil diesel (class 1) and normal butanol (n-butanol) fuel blends possessing 1 wt%, 2 wt%, 3 wt%, and 4 wt% (by mass) of n-butanol-bound oxygen fractions were prepared by pouring 4.65 wt% (BD1), 9.30 wt% (BD2), 13.95 wt% (BD3), and 18.65 wt% (BD4) n-butanol to diesel fuel. Then, load characteristics were taken when an engine with n-butanol-oxygenated fuel blends at the same speeds. Analysis of the changes occurred in the autoignition delay, combustion history, the cycle-to-cycle variation, engine efficiency, smoke, and exhaust emissions NOx, CO, THC obtained with purposely designed fuel blends was performed on comparative bases with the corresponding values measured with ‘baseline’ diesel fuel to reveal the potential developing trends.
The effect of reduced pressure on carbon dioxide flow boiling heat transfer in minichannels
- Dariusz Mikielewicz
- Blanka Jakubowska
2018
. In the paper presented are the results of the study on the effect of reduced pressure on flow boiling heat transfer data in minichannels as well as conventional ones. That effect renders that most of heat transfer correlations fail to return appropriate results of predictions. Mostly they have been developed for the reduced pressures from the range 0.1-0.3. The special correction has been postulated to the in-house model of flow boiling and condensation which modifies the two-phase flow multiplier as well as the temperature gradient in pool boiling. Four two-phase flow multiplier models were tested for this purpose, i.e. due to Friedel, Tran, Müller-Steinhagen and Heck and finally its in-house modification for applicability to minichannels. The model has been tested against a large selection of experimental data collected from various researchers to investigate the sensitivity of the in-house developed model. The collected experimental data came from various studies from literature and were conducted for the full range of quality variation and a wide range of mass velocity and saturation temperatures. In the work are presented the results of calculations obtained using the in-house developed semi empirical model on selected experimental flow boiling data related to carbon dioxide.
The effect of road restraint systems on the level of road safety - Polish experience
- Marcin Budzyński
- Kazimierz Jamroz
- Łukasz Jeliński
2018
Roadside accidents happen when a vehicle runs off the road. The majority of these accidents are very severe because leaving the road is usually followed by hitting a solid obstacle (tree, pole, support, culvert front wall, barrier). Roadsides are some of the most important issues of road safety. They have been studied for years to identify roadside hazards and the effectiveness of road safety measures such as restraint systems. While restraint systems prevent crashes into obstacles or running off the road down steep slopes, they are obstacles themselves. If wrongly designed and located, restraints may pose a serious risk to the safety of road users. Examples of safety barrier models were analysed to understand how barriers change safety. It was found that the models differ and use different methodologies and data. In building a new analytical tool, the models’ differentiating factors were combined to create a comprehensive model to match the Polish conditions. Fieldwork focussed on sections outside built-up areas, i.e. on national roads of the total length of app. 3,000 km. The data were inventoried separately for the left and right edge of the road and for the central reservation. Potential roadside hazards were identified (e.g. trees, slopes, utility poles, engineering structures) as well as the type of cross-section and existing types of safety barriers (concrete, steel, wire rope). Using the data collected, models of road safety measures were developed. By combining the effect of the roadside and safety measures, the models will help to build tools for road network management at the operational level (concrete locations on the road network) and select the right types of restraint systems and design the clearance zone.
The effectiveness of polymer adhesive in reduction of vibrations of structural members
- Natalia Lasowicz
- Arkadiusz Kwiecień
- Robert Jankowski
2018 Full text MATEC Web of Conferences
In this paper, the idea of using polymer adhesive as a damping layer is proposed. An experimental study of two aluminium cantilevered beams has been conducted. One of them presents a plain cantilevered beam, while the second one considers two aluminium beams bonded with a polymer adhesive of different thickness (0,5; 1,2; 1,75; 3,1 and 5 mm). The polymer adhesive considered in the study is a specially designed flexible two-component grout, which has high damping properties. The aim of the study is to determine dynamic parameters, such as natural frequencies and damping ratios of both beams, based on the tests in which analyzed elements have been induced to vibrations by a modal hammer. The behaviour of the beams under different additional weight, installed at the end of elements, has been studied. The results of the study clearly show that the response of the composite aluminium beam with polymer adhesive inside is substantially different then the response of the plain beam. The application of polymer adhesive leads to significant increase in structural damping. Based on the results, the method of using the polymer adhesive can be considered as an effective one in reduction of structural vibrations.
The effects of offshoring to low-wage countries on domestic wages: a worldwide industrial analysis
- Joanna Wolszczak-Derlacz
- Aleksandra Parteka
2018 Full text Empirica
This paper extends the literature on the implications of offshoring for labour markets by investigating its effect on the wages of different skill groups in a broad global context. The analysis draws on input–output data from the WIOD project, and in the panel analysed (13 manufacturing industries, 40 countries, 1995–2009) we account for up to 96 % of the international trade in manufacturing inputs. Being particularly interested in the wage effects of offshoring to low-wage countries (LWC), we use precise LWC classifications (varying across industries and time) to decompose overall offshoring by source country. We use a decomposition of the conventional offshoring measure in order to capture its pure international component, which is further instrumented using a gravity-based strategy. According to the estimation results, the negative impact of offshoring on wages mainly concerns low and medium skilled workers. However, in terms of magnitude, the downward pressure on domestic wages exhibited by offshoring to LWC is relatively small.
The effects of perceived risk, brand value, and brand trust on eWOM
- Magdalena Brzozowska-Woś
2018 Full text Handel Wewnętrzny
Unrestricted access to the Internet, mobile devices, social applications and offering shopping comment options via online stores and platforms, encourages customers to generate online reviews about brands. That is why it became important to learn about the factors that motivate customers to create electronic word of mouth (eWOM). The survey aimed to check if there are links between perceived brand value, perceived risk, brand trust and consumers' willingness to express opinions online about products bought online. Structural equation modelling (SEM) was applied to analyse the data from the study (340 respondents). Five of the six hypotheses were confirmed. The direct impact of perceived brand value on generating eWOM has not been established. Perceived product value has a more significant effect on brand trust than perceived risk. The adverse effect of perceived risk on the perceived brand value by consumers was also confirmed. It also turned out that trust in the brand has a more significant effect on the significance of eWOM than the perceived risk.
The efficiency and technological reliability of biogenic compounds removal during long-term operation of a one-stage subsurface horizontal flow constructed wetland
- Krzysztof Jóźwiakowski
- Piotr Bugajski
- Karolina Kurek
- Maria De
- Maria Almeida
- Tadeusz Siwiec
- Gabriel Borowski
- Wojciech Czekała
- Jacek Dach
- Magdalena Gajewska
2018 SEPARATION AND PURIFICATION TECHNOLOGY
The paper presents the results of a study of the efficiency and technological reliability of total nitrogen and total phosphorus removal during long term operation of a one-stage constructed wetland system with subsurface horizontal wastewater flow. The flow rate of the wastewater treatment plant was 1.2m3/d during the research period. Physical and chemical analyses of raw wastewater and treated effluent were carried out in the years 1997–2010 (14 years). During this study period, 56 series of analyses were performed and 112 wastewater samples were collected. It was observed that the average efficiency of total nitrogen and total phosphorus removal amounted to 51% and 73%, respectively. The technological reliability, determined by means of the Weibull reliability method, was 45% for total nitrogen removal and 48% in the case of total phosphorus removal. Total nitrogen and total phosphorus concentrations in the treated wastewater did not exceed the permissible values in 39.3% and 37.5% of cases, respectively. A negative correlation was found between the sorption capacity of the soil-plant filter for the removal of total phosphorus and the time of plant operation. The efficiency of total nitrogen removal was stable over time.
The Emission and Combustion Characteristics of Marine Diesel Engine with Extreme Throttled of Air or Exhaust Ducts
- Jerzy Kowalski
2018 Full text New Trends in Production Engineering
Presented paper shows the results of the laboratory tests on the relationship between the extreme throttling of both air intake duct and exhaust gas duct and gaseous emission from the marine engine. The object of research is a laboratory, 4-stroke, DI diesel engine, operated at loads from 50 kW to 250 kW at a constant speed equal to 750 rpm. During the laboratory tests the thermodynamic and exhaust gas emission characteristics of the engine were measured with technical condition recognized as "working properly" and with simulated throttling of both air intake duct and exhaust gas duct. Air intake duct throttling by 60% causes visible changes at both gas temperature and pressure behind the intercooler. The study results show significant changes of NOx and CO2 emission for considered air intake duct throttling. The best indicator of exhaust gas duct throttling among considered thermodynamic parameters of the engine is mean in-cylinder pressure. In the case of measuring the composition of exhaust gas, the throttling of the exhaust gas duct causes visible changes in CO2 and NOx emission. The conclusion is that the results of measurements of the composition of the exhaust gas may contain valuable diagnostic information about the technical condition of air intake and exhaust gas duct of the marine engine