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Ostatnie pozycje
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DESIGN LOGICAL LINGUISTIC MODELS TO CALCULATE NECESSITY IN TRUCKS DURING AGRICULTURAL CARGOES LOGISTICS USING FUZZY LOGIC
- Ievgen Medvediev
- Dmitriy Muzylyov
- Natalya Shramenko
- Pavlo Nosko
- Peter Eliseyev
- Vitalii Ivanov
: The study is aimed to develop the logic-linguistic models to design a number of rules for the correct calculation of the vehicles needed, taking into account the technical, technological, and weather and climate conditions of the harvesting and transport complex. The article has shown that the construction of the design of logic-linguistic models was not performed earlier to solve the problem of the agro-industrial production transportation support, considering the opportunity of forecasting size of influences of the weather and climatic factors on improving the productivity of the harvesting and transport complex elements. It is determined that the experience of applying the fuzzy logic theory in many practice situations confirms the universality of the mathematical apparatus. This toolkit provides better results than classical approaches (set theory, probability theory). This aspect indicates the expediency of the chosen mathematical apparatus for solving the tasks. The article using fuzzy logic explores the relationship and interdependence of technical, technological factors and weather and climate conditions for modeling transport support in harvesting and transport complex. Fuzzification of the parameters is carried out, based on the compiled equations using trapezoidal and triangular membership functions. The set of rules necessary for the creation of logical-linguistic models (LLM) for each factor has been arranged. LLMs were developed for dependent parameters, which will allow further modeling of the transport support of the harvesting and transport complex in the Fuzzy Logic Toolbox application of the MATLAB package.
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Design of battery charging system update for glider launcher
- Wojciech Rosiński
- Szymon Potrykus
- Michał Michna
This paper presents an innovative solution for increasing life of lead-acid batteries used in a glider launcher. The study is focused on upgrading a charging system instead of a costly full replacement of it. Based on literature review, the advanced three-stage charging profile was indicated. The new topology of the power converter was proposed and a simulation model was developed. A simulation study was performed which leads to a conclusion that the suggested solution can be successfully applied to the studied device. As a result, the conclusion of this work is the recommendation for modification of the launching system with an additional converter enabling 3 stage charging.
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Design of new cholinesterase inhibitors based on phosphorus analogs of tacrine as potential anti-Alzheimer’s disease agents
- Maja Przybyłowska
- Krystyna Dzierzbicka
- Iwona Inkielewicz-Stępniak
Based on the analysis of the determined free binding energy (using the AutoDock Vina 1.1.2 docking program), the most potent cholinesterase inhibitors were selected. Moreover, studies of 3D visualization of the results of molecular modeling led to the identification of potential sites for the interaction of new potential inhibitors with amino acid residues building active sites of investigated cholinesterases.
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Design of optimal state feedback controller with observer for multidimensional electrical system
- Robert Piotrowski
- Maciej Szafrański
- Konrad Żuk
From the control point of view, two-input-two-output RC electrical system is a linear and multidimensional system. In this paper, integral control and closed-loop observer are verified whether they can be used and designed. To verify this, Kalman tests are made. These structures are presented and discussed. Integral Control is tested with some base disturbances impact and checked whether it can handle them. The estimated values from the observer are compared with the original states. Simulation tests and real tests of control systems are presented.
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Design of poroelastic wearing course with the use of direct shear test
- Dawid Ryś
- Piotr Jaskuła
- Marcin Stienss
- Cezary Szydłowski
Poroelastic Road Surfaces (PERS) are characterized by porous structure with at least 20% of air void content and stiffness almost 10 times lower than typical asphalt course. Such properties enable noise reduction up to 12 dB in comparison to SMA 11 mixture. However, the main disadvantage of previously used poroelastic mixtures, based on resin type binders, was their low durability, which resulted in raveling and delamination from the lower layer. This paper presents initial results obtained for new type of PERS mixture, based on highly modified bitumen as a binder instead of resin type binder. The direct shear test was applied to estimate resistance of the mixture to raveling as well as to evaluate interlayer bond quality. Observations of first short test sections with different compositions of new PERS mixtures yielded promising results.
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Design of power cable lines partially exposed to direct solar radiation – special aspects
- Stanisław Czapp
- Seweryn Szultka
- Adam Tomaszewski
Power cable lines are usually buried in the ground. However, in some cases, their ending sections are mounted along the supports of overhead lines. This leads to a situation where the cables are exposed to direct solar radiation and, consequentially, overheat. The paper presents the advanced computer modelling of power cables’ heating, considering their insolation as well as the effect of wind. The temperature and current-carrying capacity of power cables – during exposure to direct solar radiation – are evaluated. An effective method of limiting the unfavourable impact of the sun is discussed. In the presence of solar radiation, the proposed method enables a significant increase in the power cables current-carrying capacity.
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Design of Resilient Vehicle-to-Infrastructure Systems
- Jacek Rak
- Magnus Jonsson
- Alexey Vinel
- Karol Jurczenia
Vehicular ad hoc networks (VANETs) have recently gained noticeable attention due to advantages in improving road traffic safety, shaping the road traffic and providing infotainment opportunities to travellers. However, transmission characteristics following from the IEEE 802.11p standard and the high mobility of VANET nodes remarkably reduce the lifetime, reach and capacity of wireless links, and often lead to simultaneous disruptions of communications at multiple links. In this chapter, we present a set of solutions to enhance the performance of VANETs (which can be applied independently of particular applications) concerning (a) design of the VANET infrastructure (location of road-side units—RSUs and gateways), (b) communications along vehicle-to-infrastructure (V2I) links and (c) resilience of VANET services to malicious human activities.
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Design, synthesis and high antitumor potential of new unsymmetrical bisacridine derivatives towards human solid tumors, specifically pancreatic cancers and their unique ability to stabilize DNA G-quadruplexes
- Ewa Paluszkiewicz
- Barbara Horowska
- Barbara Borowa-Mazgaj
- Grażyna Peszyńska-Sularz
- Jolanta Paradziej-Łukowicz
- Ewa Augustin
- Jerzy Konopa
- Zofia Mazerska
New promising unsymmetrical bisacridine derivatives (UAs), have been developed. Three groupsincluding 36 compounds were synthesized by the condensation of 4-nitro or 4-methylacridinone, imi-dazoacridinone and triazoloacridinone derivatives with 1-nitroacridine compounds linked with anaminoalkyl chain. Cytotoxicity screening revealed the high potency of these compounds against severaltumor cell lines. Particularly, imidazoacridinone-1-nitroacridine dimers strongly inhibited pancreaticPanc-1, Mia-Pa-Ca-2, Capan-2 and prostate cancer DU-145 cell growth. The studied compounds showedvery strong antitumor activity (T/C>300%) against Walker 256 rat adenocarcinoma. The selected 26 UAswere tested against 12 human tumor xenografts in nude mice, including colon, breast, prostate andpancreatic cancers. The studies on the molecular mechanism of action demonstrated that these un-symmetrical dimers significantly responded to the presence of G-quadruplex not to dsDNA. Structure-activity relationships for UAs potency to G-quadruplex stabilization indicated that thermal stability ofthis drug-G-quadruplex complex depended not only on the structure of heterocyclic rings, but also onthe properties of dialkylamino chains of the ring linkers. In conclusion, the presented studies identifiedthe new group of effective antitumor agents against solid human tumors, particularly pancreatic Panc-1,BxPC-3 and Mia-Pa-Ca-2 and strongly indicated their distinctive interactions with DNA. In contrast tomonomers, G-quadruplex not dsDNA is proposed to be thefirst molecular target for these compounds.
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Design thinking (DT) for the design and planning education of engineer-architects
- Dorota Kamrowska-Załuska
- Tomasz Parteka
Engineers are facing new challenges connected with globalisation, digitisation and the increased complexity of the design process. This calls for new, more interdisciplinary and user-oriented approaches to problem- solving. In this article, the authors analyse design thinking (DT) as a method to support the education of engineers specialising in architecture and urban planning. Identified in this study are the opportunities this method offers to solve design and planning problems, as well as the limitations of the method. It is based on experience gained, while conducting regional and urban planning courses for engineers in the Faculty of Architecture at Gdańsk University of Technology (FA-GUT). Gdańsk, Poland, The design thinking method is not a remedy for all design problems, but the user-centric, iterative and experimental approach that can help to prepare future professionals to conduct participatory design in the changing conditions of the modern world.
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Designing control strategies of aeration system in biological WWTP
- Robert Piotrowski
- Tomasz Ujazdowski
The paper presents the complete design processes of a novel aeration control systems in the SBR (Sequencing Batch Reactor) wastewater treatment plant (WWTP). Due to large energy expense and high influence on biological processes, the aeration system plays a key role in WWTP operation. The paper considers the aeration system for a biological WWTP located in the northeast of Poland. This system consists of blowers, the main collector pipeline, three aeration lines with different diameters and lengths, and diffusers. Classical control systems applied for this type of installation are based on PID (Proportional–Integral–Derivative) controllers, the settings of which are often found experimentally. The article presents the optimization of these settings and the design of an alternative control algorithm – the fuzzy controller.
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Designing of Parking Spaces on Parking Taking into Account the Parameters of Design Vehicles
- Miroslava Mikusova
- Jamshid Abdunazarov
- Joanna Żukowska
- Juraj Jagelcak
Nowadays, in all cities, there is an acute problem of a lack of parking spaces. The number of vehicles is constantly increasing not only in big cities and megacities, but also in small towns of the country, and there are not enough parking places—the pace of solving the problem is several times slower than the growth rate of transport among citizens. The paper is dedicated to the determination of an optimal size of a parking place for design vehicles in a parking space as an element of roads. In the example of passenger cars and trucks, the optimal number of parking places is presented. The results of the research on the dimensioning of parking spaces serve as recommendations and can be used for the design of objects of transportation infrastructure. According to the research, authors introduce the term “design vehicle” and provide its definition. They also figure out optimal parameters for each design vehicle and recommend a special template for designing parking places.
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DESIGNING OF PARKING SPACES TAKING INTO ACCOUNT THE PARAMETERS OF DESIGN VEHICLES IN RUSSIA
- Miroslava Mikusova
- Jamshid Abdunazarov
- Joanna Żukowska
- Alisher Usmankulov
Nowadays, in all the cities, there is an acute problem of a lack of parking spaces. The number of vehicles are becoming more and more larger, not only in megacities, but in small cities of the country, as well and there are no more parking places - the pace of solving the problem is several times slower than the rate of the transport growth among the citizens. The article is dedicated to the determination of the optimum sizes parking place for designing vehicles on a parking space, which is an element of the roads. The optimum amount parking places are determined on examples of the passenger cars and trucks. The results of research on dimensioning of parking spaces and recommendations to use the results for design of objects of transportation infrastructure are presented. According to the research, authors included the term "design vehicle" and gave its definition. The authors developed a template for 7 types of design vehicles and their sizes and also recommended sizes for longitudinal parking for each of their design vehicles. The optimum parking plot angles are determined, as well.
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Design-oriented computationally-efficient feature-based surrogate modelling of multi-band antennas with nested kriging
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
Design of modern antenna structures heavily depends on electromagnetic (EM) simulation tools. EM analysis provides reliable evaluation of increasingly complex designs but tends to be CPU intensive. When multiple simulations are needed (e.g., for parameters tuning), the aggregated simulation cost may become a serious bottleneck. As one possible way of mitigating the issue, the recent literature fosters utilization of faster representations, or surrogates, of the system at hand. Notwithstanding, conventional models are severely affected by the curse of dimensionality. In practice, modelling of antenna structures described by no more than a few parameters over narrow parameter ranges is possible. In the context of the structural complexity of modern antennas, this is hardly acceptable. This paper presents a novel technique for cost-efficient design-oriented modelling of multi-band antennas. Our approach integrates a recently reported nested kriging framework and the response feature technology. This combination enables rendering of reliable surrogates valid within broad ranges of geometry parameters while using small training data sets. Benchmarking against conventional modelling methods demonstrates superiority of the proposed framework in terms of both the predictive power of the surrogate and its setup cost. Design applications for antenna optimization are discussed as well.
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Design-oriented modeling of antenna structures by means of two-level kriging with explicit dimensionality reduction
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
The employment of full-wave electromagnetic (EM) analysis is a practical necessity in the design of contemporary antenna structures. This is because simpler models are generally not available or of limited accuracy. At the same time, EM-based design is computationally expensive. Consequently, the ways of accelerating tasks such as parametric optimization or uncertainty quantification have to be sought. A possible workaround that has been gaining popularity over the recent years is utilization of fast surrogates. Among these, data-driven models are the most popular due to their versatility and easy handling. Notwithstanding, the curse of dimensionality and utility requirements (e.g., having the surrogate valid over broad ranges of geometry and operating parameters) limit the applicability of conventional approximation approaches to antenna modeling. Recently proposed performance-driven methods, especially the nested kriging framework, allow for going beyond the capability of the standard techniques. This is achieved by an appropriate confinement of the model domain, defined to contain only high-quality designs with respect to the selected performance figures. This paper proposes a novel approach, which combines the main idea of the nested kriging, specifically, the first-level model as a tool for constructing the domain-defining manifold, as well as principal component analysis to reduce the domain dimensionality in an explicit manner. Comprehensive benchmarking using three antenna structures indicates superiority of our methodology over conventional techniques, but also nested kriging, in terms of the achievable predictive power. The latter is obtained without compromising design utility of the model as demonstrated through application case studies.
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Design-Oriented Two-Stage Surrogate Modeling of Miniaturized Microstrip Circuits with Dimensionality Reduction
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
- Muath Al-hasan
Contemporary microwave design heavily relies on full-wave electromagnetic (EM) simulation tools. This is especially the case for miniaturized devices where EM cross-coupling effects cannot be adequately accounted for using equivalent network models. Unfortunately, EM analysis incurs considerable computational expenses, which becomes a bottleneck whenever multiple evaluations are required. Common simulation-based design tasks include parametric optimization and uncertainty quantification. These can be accelerated using fast replacement models, among which the data-driven surrogates are the most popular. Notwithstanding, a construction of approximation models for microwave components is hindered by the dimensionality issues as well as high nonlinearity of system characteristics. A partial alleviation of the mentioned difficulties can be achieved with the recently reported performance-driven modeling methods, including the nested kriging framework. Therein, the computational benefits are obtained by appropriate confinement of the surrogate model domain, spanned by a set of pre-optimized reference designs, and by focusing on the parameter space region that contains high quality designs with respect to the considered performance figures. This paper presents a methodology that incorporates the concept of nested kriging and enhances it by explicit dimensionality reduction based on spectral decomposition of the reference design set. Extensive verification studies conducted for a compact rat-race coupler and a three-section impedance matching transformer demonstrate superiority of the presented approach over both the conventional techniques and the nested kriging in terms of modeling accuracy. Design utility of our surrogates is corroborated through application cases studies.
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Detection and Imaging of Debonding in Adhesive Joints of Concrete Beams Strengthened with Steel Plates Using Guided Waves and Weighted Root Mean Square
- Erwin Wojtczak
- Magdalena Rucka
- Magdalena Knak
Strengthening of engineering structures is an important issue, especially for elements subjected to variable loads. In the case of concrete beams or slabs, one of the most popular approaches assumes mounting an external reinforcement in the form of steel or composite elements by structural adhesives. A significant disadvantage of adhesive joints is the lack of access to the adhesive film for visual condition assessment, thus, there is a need for non-destructive diagnostics of these kinds of connections. The aim of this paper was the identification and visualization of defects in adhesive joints between concrete beams and steel plates using the guided wave propagation technique. The initial theoretical and numerical analyses were performed. The experimental wave field was excited and measured by the scanning laser Doppler vibrometry. The collected signals were processed by the weighted root mean square (WRMS) calculation. As a result, 2-D damage maps were obtained. The numerical simulations were performed to corroborate the experimental results. The results showed that the guided waves could be successfully applied in non-destructive diagnostics of adhesive joints between concrete and steel elements. However, the quality of damage visualizations strongly depended on the location of excitation.
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Detection and size estimation of crack in plate based on guided wave propagation
- Beata Zima
- Rafał Kędra
The paper presents results of the comprehensive theoretical and experimental investigation of crack detection in metallic plate using guided wave propagation. The main aim of the paper is to develop the novel method which would allow for linear crack size estimation with the use of minimal number of the transducers. In general, there exists the relation between length of the propagation path and the wave amplitude value. However, we have shown that the amplitude value can be also influenced by the interaction with the damage. The meaningful differences in the amplitudes of waves reflected from various damage zones (the end and middle point) have become the foundation of the novel algorithm of line-crack detection. All stages of the algorithm have been described in detail and then the experimental tests were conducted. The experimental investigation involved crack detection and its size estimation for four different configurations of piezo transducers. Each configuration consisted of one actuator and three sensors, what which so far was the minimum number of sensors for point damage detection. The damage maps created on the basis of the collected time-domain signals visualized the exact crack orientation in each case. It has been revealed that the developed algorithm allows also for determining the crack size when the configuration of the transducers is designed properly.
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Detection, identification and determination of chiral pharmaceutical residues in wastewater: Problems and challenges
- Aysegul Dogan
- Justyna Płotka-Wasylka
- Dagmara Kempińska-Kupczyk
- Jacek Namieśnik
- Agata Kot-Wasik
Chiral pharmaceuticals (CPs) are widely used in different areas of human life, thus they are frequentlydetected in different ecosystems. However, before CPs reach the environment, wastewater is subjected todifferent treatment processes in order to remove them. Nevertheless, such processes may affect thechirality of CPs, thus it is very important to monitor CP levels during the wastewater treatment.This review addresses the present state of knowledge concerning the input, occurrence, fate and ef-fects of CPs in the environment. It focuses primarily on wastewater analysis, problems and challengesconnected with trace levels of CP enantiomers and highly complex matrices of samples. Analytical ap-proaches used in detection, identification and determination of enantiomers are presented. The appli-cation of the results of wastewater analysis to obtain information on the population's health andbehaviour has been included and discussed. Moreover, the prospects of the future trends in greenenantiomeric analysis are described.
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Detection of debonding in reinforced concrete beams using ultrasonic transmission tomography and hybrid ray tracing technique
- Monika Zielińska
- Magdalena Rucka
This paper concerns inspection of reinforced concrete elements, with particular emphasis on assessing the quality of the adhesive connection between steel and concrete. A novel theoretical model was developed to determine the paths of transmitted, refracted and reflected elastic waves as well as a creeping wave propagated along the inclusion surface. Imaging the internal structure of tested beams was based on wave propagation measurements carried out on their surface and computed tomography. The ray tracing was performed by the hybrid approach as a combination of the network theory and the ray bending methods. The obtained results indicated a great potential of ultrasonic tomography in detection of debonding in reinforced concrete structures.
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DETERMINATION OF ADDITIONAL TENSION IN TOWED STREAMER CABLE TRIGGERED BY COLLISION WITH UNDERWATER MOVING OBJECT
- Vladimir Blintsov
- Konstantin Trunin
- Wiesław Tarełko
The paper deals with issues connected with the behaviour of a streamer cable towed by a survey seismic vessel when the cable undergoes a strike triggered by collision with an underwater moving object. The consequences of such collisions may be both threat to the life of marine animals or damage to underwater units and large economic losses suffered by vessel owners. The risk of such collisions has increased over the last years as a result of increased offshore seismic survey operations. Therefore, a towed streamer should be very robust. To assure its robustness, we should know the deformation mechanism of a single streamer cable. This in turn requires the development of an appropriate mathematical model of such a phenomenon. In particular, the paper presents the characteristics of seismic survey vessels and streamers; an analysis of collisions that have occurred in the past; a statement of the problem, and a computer-aided system supporting simulation of the cable behaviour. To obtain all the necessary design parameters regarding the deformation mechanism of a streamer cable, we set up a dedicated computer-aided system that supports their calculation.
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Determination of aminoglycoside antibiotics: current status and future trends
- Marta Glinka
- Wojciech Wojnowski
- Andrzej Wasik
The use of aminoglycoside antibiotics is prevalent in medicine and agriculture. Their overuse increases their mobility in the environment, resulting in a need for reliable methods for their determination in a variety of matrices. However, the properties of aminoglycosides, in particular their high polarity, make the development of such methods a non-trivial task, inciting researchers to tackle this complex issue from different angles. The necessity to determine aminoglycosides in complex matrices and at low concentration levels requires the development of relatively elaborate sample preparation methods and the use of selective and sensitive detection techniques. Various modes of liquid chromatography coupled with tandem mass spectrometry are usually the analytical methods of choice. However, the recent developments in techniques such as bioassays, quantum dot-based colourimetric applications and various aptasensors point towards the development of more easily accessible and user-friendly point-of-need tests for screening applications in food control and environmental monitoring. This review summarizes the state-of-the-art in sample preparation protocols and the determination of aminoglycosides using various techniques and outlines the future trends with an emphasis placed on the novel and emerging solutions in this area.
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Determination of bromhexine and its metabolites in equine serum samples by liquid chromatography – Tandem mass spectrometry: Applicability to the elimination study after single oral dose
- Emilia Waraksa
- Katarzyna Owczarek
- Paweł Kubica
- Ewa Kłodzińska
- Mariusz Ozimek
- Robert Wrzesień
- Barbara Bobrowska-Korczak
- Jacek Namieśnik
Bromhexine (BH), expectorant used in the treatment of respiratory disorders associated with viscid or excessive mucus, is not permitted for use in the competing horse by many authorities in horseracing and Olympic disciplines. Metabolic studies are of the great importance in anti-doping field because they allow for updating the selection of the most appropriate markers for prohibited substances, such as metabolites present at higher concentration levels and/or lasted for a longer period of time in biological samples than a parent drug. This study describes LC-MS/MS-based method for simultaneous determination of BH and its metabolites, including 4-(2-amino-3,5-dibromobenzylamino)cyclohexanol (4-HDMB), 3-(2-amino-3,5-dibromobenzylamino)cyclohexanol (3-HDMB), in equine serum samples. The 2-(2-amino-3,5-dibromobenzylamino)cyclohexanol (2-HDMB) was monitored as well. The assay was validated in terms of linearity (R2 greater than 0.9951), intra- and inter-assay accuracy (91.6 – 109.1%) and precision (CV < 9.6%) as well as recovery (94.8 – 105.65%). The LODs were 0.0052, 0.0053, 0.0056 and 0.0043 ng/mL for BH, 2-HDMB, 3-HDMB and 4-HDMB, respectively. The developed method was applied to determine the time curses of BH and its metabolites concentrations in equine serum collected for 95.25 h following a single oral administration of BH to two healthy mares (in dose of 0.8 mg/kg). The parent drug was found at higher concentration levels than 3-HDMB (major metabolite) and 4-HDMB (minor metabolite), however, both BH metabolites lasted for a longer period of time in equine serum than the parent drug. Thus, both metabolites of BH can be considered as BH abuse markers.
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Determination of energy-transfer distributions in ionizing ion-molecule collisions
- Suvasthika Indrajith
- Ewa Erdmann
- Jacopo Chiarinelli
- Alicja Domaracka
- Marta Łabuda
- Lorenzo Avaldi
- Manuel Alcami
- Nestor F. Aguirre
- Sergio Díaz-Tendero
- Paola Bolognesi
- Patrick Rousseau
- Bernd Alan Huber
The main objective of this study is to determine the energy transfer occuring in ion-molecule collisions. In order to solve this problem, we followed two approaches; the first one by validating a purely experimental method and the second one by testing a new theoretical model M3C (Microcanonical Metropolis Monte Carlo).
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Determination of long-chain aldehydes using a novel quartz crystal microbalance sensor based on a biomimetic peptide
- Tomasz Wasilewski
- Bartosz Szulczyński
- Marek Wojciechowski
- Wojciech Kamysz
- Jacek Gębicki
There is an increasingly popular trend aimed at improvement of fundamental metrological parameters of sensors via implementation of materials mimicking biological olfactory systems. This study presents investigation on usefulness of the peptide mimicking HarmOBP7 region as a receptor element of the piezoelectric sensor for selective analysis of long-chain aldehydes. Identification of odorant binding proteins creates new possibilities for design of peptides mimicking binding properties of their volatile compounds. Exploration of OBPs and new peptide sequences capable to effectively bind volatile compounds is necessary to enhance artificial olfaction. For the development of biosensors where simple detection is crucial rather than identification of subsequent metabolic activity, the use of sub-protein components (e.g. ligand-binding regions or synthetic peptides) is still escalating. Bearing all this in mind, a segment of a peptide sequence associated with a specific function of HarmOBP7 (involved in binding the long-chain aldehydes) has been designed, synthesised and immobilised on a piezoelectric transducer. The results of in silico investigations were correlated with the experimental measurements of gas substances. The correlated results confirm a high selectivity of the KLLFDSLTDLKKKMSEC-based sensor with respect to long-chain aliphatic aldehydes including octanal, decanal, undecanal, nonanal and helional. Odorant molecules interact with recognition peptide with specific affinities. The lowest limit of detection, 14 ppm was calculated for nonanal. The results can throw a new light on the possibility of synthetic peptide application as a receptor layer in biosensors in odorants analysis.
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Determination of phenol biodegradation pathways in three psychrotolerant yeasts, Candida subhashii A011, Candida oregonensis B021 and Schizoblastosporion starkeyi-henricii L012, isolated from Rucianka peatland
- Natalia Filipowicz
- Malwina Momotko
- Grzegorz Boczkaj
- Hubert Cieśliński
In this study, three psychrotolerant phenol-degrading yeast strains Candida subhashii (strain A011), Candida oregonenis (strain B021) and Schizoblastosporion starkeyi-henricii (strain L012) isolated from Rucianka peatland were examined to determine which alternative metabolic pathway for phenol biodegradation is used by these microorganisms. All yeast strains were cultivated in minimal salt medium supplemented with phenol at 500, 750 and 1000 mg l−1 concentration with two ways of conducting phenol biodegradation experiments: with and without the starving step of yeast cells. For studied yeast strains, no catechol 2,3-dioxygenase activities were detected by enzymatic assay and no products of catechol meta-cleavage in yeast cultures supernatants (GC–MS analysis), were detected. The detection of catechol 1,2-dioxygenase activity and the presence of cis,cis-muconic acid in the analyzed samples revealed that all studied psychrotolerant yeast strains were able to metabolize phenol via the ortho-cleavage pathway. Therefore, they may be tested in terms of their use to develop biotechnology for the production of cis,cis-muconic acid, a substrate used in the production of plastics (PET) and other valuable goods.
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DETERMINATION OF SEAKEEPING PERFORMANCE FOR A CASE STUDY VESSEL BY THE STRIP THEORY METHOD
- Karol Niklas
- Artur Karczewski
The increase of seakeeping performance is of particular importance for car and passenger ferries, service ships in the gas and oil extraction industry and offshore wind power farm industry, as well as for special purpose ships (including military applications). In the water areas of the Baltic Sea, North Sea, and Mediterranean Sea, which are characterised by a short and steep wave, the hull shape has a substantial impact on the operational capacity and propulsion efficiency of the ship, as well as on comfort and safety of navigation. The article analyses selected aspects of seakeeping for four variants of a selected case study vessel, indicating practical limitations of the strip method. The analysed aspects included hull heaving and pitching, added resistance, Motion Thickness Indicator (MSI), and Subjective Magnitude (SM). Experimental tests were also performed in the towing tank. Their comparison with the numerical results has indicated high inaccuracy of the strip method. What is more, the simplified representation of hull shape used in the strip method makes it impossible to analyse the effect of hull shape changes on the predicted seakeeping characteristics. Especially for the case of head wave, neglecting highly non-linear phenomena, such as slamming or head wave breaking, in strip method-based computer simulations will significantly decrease the reliability of the obtained results. When using the strip method, the seakeeping analysis should be complemented with model tests in a towing tank, or by another more complex numerical analysis, such as CFD for instance.
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Determination of the Bending Properties of Wire Rope Used in Cable Barrier Systems
- Dawid Bruski
This paper presents research on the bending properties of 3 × 7 19-mm wire rope commonly used in road cable barriers. A total of 19 experimental tests were conducted. In addition, two nonlinear 3D numerical models of the wire rope using beam and solid finite elements were developed. Based on these models, four numerical simulations were carried out. The numerical results were validated against the experimental ones and a very good agreement was obtained. The main result of the research is the determination of the moment–curvature relationship for the wire rope considered. The effect of prestretching on the rope performance is discussed. The numerical results are analyzed in this paper in detail, including the behavior of the wire rope under bending and analyses of the cross-sectional and contact stresses. Suggestions concerning the type of finite element for wire rope modeling are also given. The results can be used, for example, in numerical simulations of crash tests of cable barriers.
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Determination of the dynamic critical maneuvering area in an encounter between two vessels: Operation with negligible environmental disruption
- Mateusz Gil
- Jakub Montewka
- Przemysław Krata
- Tomasz Hinz
- Spyros Hirdaris
This paper introduces the concept of Collision Avoidance Dynamic Critical Area (CADCA) for onboard Decision Support Systems (DSS). The indicator proposed is derived via identification of a minimum required maneuvering zone in an encounter between two vessels. The CADCA model accounts for ship maneuvering dynamics and associated hydrodynamic actions emerging from different rudder angles and forward speed effects. The method presented is novel as it considers the variability of a critical area due to dynamic changes in operational parameters for both vessels. Results of the simulations carried out in negligible weather conditions confirm that computed zones may differ significantly in terms of shapes and limits. It is demonstrated that the size of the CADCA depends on the rudder angle, forward speed, as well as the dimensions of the vessels.
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DETERMINATION OF THE EFFECT OF ENVIRONMENTAL FACTORS ON THE CORROSION OF WATER DISTRIBUTION SYSTEM BASED ON ANALYSIS OF ON-LINE CORROSION MONITORING RESULTS
- Agata Jażdżewska
- Maciej Gruszka
- Robert Mazur
- Juliusz Orlikowski
- Jacek Banaś
Corrosion of water distribution system is a significant issue causing problems with quality, safety and continuity of distribution. The changes of corrosion rates of the water distribution systems in Cracow made of carbon steel were investigated by analysis of online corrosion monitoring system results. Corrosion rates were determined using the linear polarization method. The impact of rain, temperatures, conductivity, dissolved oxygen content on corrosion rate were characterized. The corrosivity of different water sources like mountain water, underground water or river water were indicated. The possible actions for reducing corrosion losses were characterized. Results show that pollution of the environment in the form of acid rain and runoff from agriculture as well as the type of the source water has significant influence on corrosion of water distribution system. Corrosion monitoring system gives possibility of controlling corrosion rate by mixing waters from different sources in the way to obtain less corrosive mixture
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DETERMINATION OF THE HYDROXYL NUMBER OF GROUND TIRE RUBBER PARTICLES VIA MODIFIED TEST METHOD FOR ISOCYANATE GROUPS
- Aleksander Hejna
- Paulina Kosmela
- Adam Olszewski
- Łukasz Zedler
- Krzysztof Formela
Nowadays, considering the environmental trends and law regulations associated with the circular economy, it is very important to seek for the methods of by-products and waste utilization. The example of such material, which requires the attention and recycling method is ground tire rubber generated during recycling of post-consumer car tires. It can be introduced into various polymer matrices as a filler, but to enhance its effectivity it is essential to guarantee the interfacial compatibility. Therefore, the fast and simple methods for determination of the waste rubber chemical structure are needed. In the presented paper, we are presenting the method for the determination of hydroxyl number of ground tire rubber, based on the modified standard test method for isocyanate groups. Hydroxyl number is used as a quantitative measure of the hydroxyl groups content, which is essential during manufacturing of multiple polymeric materials, such as polyurethanes, epoxy resins, polyesters or polyamides. Moreover, the presence of hydroxyls on the rubber surface may be exploited during compatibilization of composites.
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Determination of the theoretical and actual working volume of a hydraulic motor
- Paweł Śliwiński
A new methodology of determination of the theoretical and actual working volume of a hydraulic motor based on the characteristics of the delivered flow rate into hydraulic motor vs. the rotational speed at a constant pressure drop in the working chambers is described in this paper. A new method of describing the delivered flow rate into a motor per one shaft revolution as a nonlinear function of the pressure drop in the motor working chamber is proposed. The influence of the flowmeter location in the measurement system on the result of the theoretical and actual working volume calculation is described. It is shown that, in order to assess the energy losses (volumetric and mechanical) in the motor, the actual working volume must be a polynomial function (third degree) of its pressure drop in the working chambers. The result of the experimental tests of the satellite hydraulic motor confirmed the validity of the proposed method. The result of the calculation of the theoretical working volume of the motor according to the proposed method was compared with the results of calculations according to known methods.
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Determination of the tram track axis using a multi receiver GNSS measurement system
- Andrzej Wilk
- Cezary Specht
- Władysław Koc
- Krzysztof Karwowski
- Jacek Skibicki
- Jacek Szmagliński
- Paweł Dąbrowski
- Mariusz Specht
- Marek Zienkiewicz
- Sławomir Judek
- Piotr Chrostowski
- Marcin Skóra
- Sławomir Grulkowski
This article refers to research, that has been conducted by an interdisciplinary research team from the Gdańsk University of Technology and the Maritime University in Gdynia since 2009. These investigation concerns the determination of a railway track axis using the mobile satellite measurement technique. Following the dynamic development of GNSS techniques, that could be seen in the last decade, the team carried out further experiments aimed at developing an effective measurement method. Using the acquired experience in this period, another measurement campaign was carried out on the tram tracks in Gdansk. The main goal of these measurements was to check how the new assumptions regarding the method of mounting the antennas as well as their placement on the measuring platform will work in various field conditions. For this purpose, ten sets of GNSS receivers offered by two independent manufacturers – currently market leaders – were used. The choice of testing track section made it possible to analyze the repeatability of results obtained from multiple measurements in conditions of varying GNSS signal availability. The article presents in a synthetic way the course of this research and the obtained results.
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DETERMINATION OF VERTICAL DISPLACEMENTS IN RELATIVE MONITORING NETWORKS
- Daria Filipiak-Kowszyk
- Waldemar Kamiński
The problem of determining displacements of objects is an important and current issue, in particular in terms of operational safety. This is a requirement that covers geodetic, periodic control measurements in order to determine horizontal and vertical displacements. The paper is focused on the analysis of vertical displacements. Geodetic measurements and their interpretation allow to reduce the risk of possible structural catastrophes. The major research topic of the majority of available papers is displacement determination of individual controlled points, in a situation where there are identified as fixed reference points. There are cases making identification of such points difficult or impossible to use in displacement analysis. This paper addresses a rare case of determining vertical displacements in unstable reference systems. Due to the fact that most of the existing and known literature methods do not always bring satisfactory results, the paper propose a new method of vertical displacement determination in the absence of reference points in the local coordinate system. Practical considerations on simulated data show that the presented method performs the task correctly.
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Developing students' spatial skills and teaching the history of architecture through structural drawing
- Maria Sołtysik
The method of “structural drawing" is used in teaching history of architecture in the Architectural Faculty of Gdańsk University of Technology. It is addressed to students of the first semester of study – so to the architectural beginners. There are three main goals of the structural drawing method used in that educational course: (1) developing the students’ spatial skills; (2) training architectural drawing ability; (3) teaching the history of architecture. The method of structural drawing is based on creating the axonometric and the orthogonal views of the historic architectural objects, important to the outline of architecture. Every exercise lasts 1,5 hour, during which every student is creating a hand-drawing spatial study of one given object. The process of drawing is performed in a “structural” way, which means that all phases of its construction are visible and the very object is presented spatially as if it was transparent. Those are the main rules of “structural drawing”. The first part of the exercise – mostly the axonometric projection - is commented and guided by the teacher. During it the students are doing the drawings simultaneously to the drawing performed by the teacher on the table. The second part of the exercise is done by every student on his own, without the teacher’s guidance. It concerns the structural drawing of a chosen orthogonal view of the object or a chosen architectural detail.
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Development and validation of a GC–MS/MS method for the determination of 11 amphetamines and 34 synthetic cathinones in whole blood
- Mateusz Woźniak
- Laura Banaszkiewicz
- Marek Wiergowski
- Ewa Tomczak
- Marzena Kata
- Beata Szpiech
- Jacek Namieśnik
- Marek Biziuk
Purpose Psychoactive compounds that contain a phenylethylamine structure (such as amphetamine-type stimulants and synthetic cathinones) are one of the major classes of stimulants on the recreational drug market. Approximately 670 new psychoactive substances (NPS) are monitored only in Europe; however, new psychoactive compounds are being developed for illicit trade each year. In this context, the development of new analytical procedures for the determination of such compounds in biological specimens for forensic toxicology is of great importance. Methods Gas chromatography–tandem mass spectrometry (GC–MS/MS) technique was applied for analysis of amphetamines and synthetic cathinones. The volumes of 200 µL of each whole blood sample and 1 mL of liquid-liquid extraction solvent were used for extraction, followed by pentafuoropropionyl derivatization. Results A high-throughput, robust, rapid, and sensitive procedure involving a simple liquid-liquid extraction for the simultaneous determination of 45 amphetamine-type stimulants and synthetic cathinones in whole blood was developed. The assay was validated based on its recovery (83.2–106%), interday accuracy (89.0–108%), and interday precision (≤8.1%). In view of the low limits of detection (ranged between 0.02 and 0.72 ng/mL) and limits of quantifcation (1 and 2.5 ng/mL), the developed method can serve as a less expensive and more ecologically friendly alternative to the liquid chromatography–tandem mass spectrometric methods. Conclusions To the best of our knowledge, this is the frst work presenting a GC–MS/MS method for the determination of NPS in blood samples. The presented procedure was applied to authentic samples from forensic cases, demonstrating its utility in the quantifcation of a wide number of psychoactive substances in routine toxicological analyses. The developed procedure can also be easily expanded to additional compounds.
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Development of a Peptide Derived from Platelet-Derived Growth Factor (PDGF-BB) into a Potential Drug Candidate for the Treatment of Wounds
- Milena Deptuła
- Przemysław Karpowicz
- Anna Wardowska
- Piotr Sass
- Paweł Sosnowski
- Alina Mieczkowska
- Natalia Filipowicz
- Maria Dzierżyńska
- Justyna Sawicka
- Ewa Nowicka
- Paulina Langa
- Adriana Schumacher
- Mirosława Cichorek
- Jacek Zieliński
- Karolina Kondej
- Franciszek Kasprzykowski
- Artur Czupryn
- Łukasz Janus
- Piotr Mucha
- Piotr Skowron
- Arkadiusz Piotrowski
- Paweł Sachadyn
- Sylwia Rodziewicz-Motowidło
- Michał Pikuła
Objective: This study evaluated the use of novel peptides derived from platelet-derived growth factor (PDGF-BB) as potential wound healing stimulants. One of the compounds (named PDGF2) was subjected for further research after cytotoxicity and proliferation assays on human skin cells. Further investigation included evaluation of: migration and chemotaxis of skin cells, immunological and allergic safety, the transcriptional analyses of adipose-derived stem cells (ASCs) and dermal fibroblasts stimulated with PDGF2, and the use of dorsal skin wound injury model to evaluate the effect of wound healing in mice. Approach: Colorimetric lactate dehydrogenase and tetrazolium assays were used to evaluate the cytotoxicity and the effect on proliferation. PDGF2 effect on migration and chemotaxis was also checked. Immunological safety and allergic potential were evaluated with a lymphocyte activation and basophil activation test. Transcriptional profiles of ASCs and primary fibroblasts were assessed after stimulation with PDGF2. Eight-week-old BALB/c female mice were used for dorsal skin wound injury model. Results: PDGF2 showed low cytotoxicity, pro-proliferative effects on human skin cells, high immunological safety, and accelerated wound healing in mouse model. Furthermore, transcriptomic analysis of ASCs and fibroblasts revealed the activation of processes involved in wound healing and indicated its safety. Innovation: A novel peptide derived from PDGF-BB was proved to be safe drug candidate in wound healing. We also present a multifaceted in vitro model for the initial screening of new compounds that may be potentially useful in wound healing stimulation. Conclusion: The results show that peptide derived from PDGF-BB is a promising drug candidate for wound treatment.
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Development of cooperation in localized cooperation networks: A comparative study of cluster organizations and technology parks
- Anna Lis
The main aim of the paper is to analyze the level of development of cooperative relationships in localized cooperation networks – among enterprises associated in cluster organizations and park tenants. The author reports the findings from the quantitative study carried out in the selected cluster organizations and technology parks functioning in Poland. The basic method of data collection was a survey questionnaire. The research sample included 132 respondents from cluster enterprises and 137 from park tenants. In addition, a comparative analysis was conducted. The research is based on the original concept of the trajectory of development of cooperative relationships in cluster organizations. The current study focused on three main areas of inter-organizational cooperation: motivation, effectiveness, and commitment. The effectiveness of the surveyed enterprises in both groups should be assessed as quite low, while their attitude as passive. The study shows that the most common forms of cooperation are those assigned to the lowest level of cooperation – the surveyed enterprises achieved level I, regardless of their initial motivation. At this level, the surveyed enterprises also showed the greatest commitment. In contrast, it was the most difficult for them to achieve the highest level IV, which requires the highest level of commitment. The knowledge of the identified relationships among motivation, effectiveness, and commitment in cluster and park structures can help these organizations to take conscious actions aimed at developing cooperation among their members/tenants. The findings add to the state-of-the-art knowledge in the concept of industrial clusters, as they shed new light on cooperation developed within formally established organizations, based on geographical proximity, focused on the networking of their constituent companies.
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Development of proximity in cluster organizations
- Anna Lis
Sustainable development in cluster organizations (COs) is most fully manifested in the synergy effect. In turn, the synergy effect is achieved thanks to the development of proximity among cluster entities. The purpose of the paper is to test two conceptual models reflecting relations between selected dimensions of proximity in cluster organizations. The author reports the findings of a quantitative study conducted in four COs. The basic technique for collecting data was an online questionnaire. Both theoretical models were tested using Structural Equation Modelling.The research goes beyond the state-of-the-art knowledge in the concept of industrial cluster by exposing a broader view on cluster cooperation, which is developed on the basis of geographical proximity, and simultaneously contributes to the development of proximity in other dimensions: social, competence and organizational.
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Development of the New Polish Method for Capacity Analysis of Motorways and Expressways
- Piotr Olszewski
- Tomasz Dybicz
- Wojciech Kustra
- Aleksandra Romanowska
- Kazimierz Jamroz
- Ostrowski Krzysztof
The paper presents development of the new Polish method for performing capacity analysis of basic segments of dual carriageway roads (motorways and expressways). The method is based on field traffic surveys conducted at 30 motorway and expressway sites (class A and S roads) in Poland. Traffic flows, composition and travel times were observed in 15-min intervals at each site using ANPR filming method. These data were used to calibrate a family of traffic speed-flow relationships for different roads, based on Van Aerde model. Free flow speed of traffic and road class are the basic parameters defining the speed-flow relationship and the value of capacity per lane in pcu/h. Traffic density was adopted as the measure of effectiveness for defining the level of service. The paper describes derivation of formulae for estimation of free flow speed for different types of roads as well as determination of equivalent factors for converting vehicles to passenger car units. The method allows us to determine capacity and the level of service based on existing or forecasted traffic flow.
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Dia- and paramagnetic contributions to magnetizabilities of relativistic hydrogenlike atoms in some low-lying discrete energy eigenstates
- Patrycja Stefańska
In this paper we present tabulated data for relative diamagnetic and paramagentic contributions to the magnetizability ($\chi$) of the relativistic hydrogenlike atoms with a pointlike, motionless and spinless nucleus of charge $Ze$. Utilizing general analytical formulas for the diamagnetic ($\chi_{d}$) and paramagnetic ($\chi_{p}$) components of $\chi$, recently derived by us [P. Stefa{\'n}ska, 2020] with the aid of the Gordon decomposition technique, valid for an arbitrary discrete energy state, we have computed the numerical values of $\chi_{d}/\chi$ and $\chi_{p}/\chi$ for the ground state and for the first and second set of excited states (i.e.: $2s_{1/2}$, $2p_{1/2}$, $2p_{3/2}$, $3s_{1/2}$, $3p_{1/2}$, $3p_{3/2}$, $3d_{3/2}$, and $3d_{5/2}$) of the hydrogen atom ($Z=1$) and for hydrogenic ions with $2 \leqslant Z \leqslant 137$. We compare also the numerical values of the total magnetizabilities for the ground state $1s_{1/2}$ and for each state belonging to the first set of excited states of selected hydrogenlike atoms, obtained with the use of two different values of the fine-structure constant, i.e.: $\alpha^{-1}=137.035 \: 999 \: 139$ (from CODATA 2014) and $\alpha^{-1}=137.035 \: 999 \: 084$ (from CODATA 2018).
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Diagnostic Models and Estimators for LDI in Transmission Pipelines
- Zdzisław Kowalczuk
- Marek Tatara
This article considers and compares four analytical models of the pipeline flow process for leak detection and location tasks. The synthesis of these models is briefly outlined. Next, the methodology for generating data and diagnosing pipes is described, as well as experimental settings, assumptions and implemented scenarios. Finally, the quality of model-based diagnostic estimators has been evaluated for their bias, standard deviations and computational complexity. The global level of optimality served as a general indicator of the quality and performance of multidimensional estimators.
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Diamine derivatives of dimerized fatty acids and bio-based polyether polyol as sustainable platforms for the synthesis of non-isocyanate polyurethanes
- Kamila Błażek
- Paulina Kasprzyk
- Janusz Datta
A series of environmentally friendly non-isocyanate polyurethanes (NIPUs) were successfully prepared via the polyaddition reaction of bio-based polyether polyol-based cyclic carbonate with diamine derivative of dimerized fatty acids. The syntheses of NIPUs were realized by the three-step method in the absence of toxic solvents and, importantly, the process of carbonation did not require the use of elevated pressure. The effect of using various types of bio-based amines, [amine]/[cyclic carbonate] molar ratio as well as different reaction temperatures on the chemical structure and thermal properties were widely investigated by Fourier transform infrared spec-troscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), respectively. The Gaussian deconvolution technique was used to decompose the carbonyl region (-C––O) of three peaks in various samples. It was found that the molar ratio of substrates and curing temperature have an effect on the distribution of free and H-bonded carbonyl groups as well as carbonyl groups from cyclic carbonates in the chemical structure of the prepared compounds. On this basis, the role of hydrogen bonds in the chemical structure of NIPU on selected sample properties was determined. Moreover, the impact of water during 6 months of immersion on the polymer networks was examined.
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Diastereoselective Synthesis of Z‐Alkenyl Disulfides from α‐Thiophosphorylated Ketones and Thiosulfonates
- Mateusz Musiejuk
- Justyna Doroszuk
- Bartosz Jędrzejewski
- Gregory Ortiz Nieto
- Marisol Marin Navarro
- Dariusz Witt
We developed a simple and efficient method for the synthesis of functionalized unsymmetrical Z‐alkenyl disulfides under mild conditions in moderate to good yields. The designed method is based on the reaction of α‐thiophosphorylated carbonyl compounds with thiotosylates in the presence of a base. The developed method allows the preparation of unsymmetrical Z‐alkenyl disulfides bearing additional hydroxy, carboxy, or ester functionalities
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Diatoms Biomass as a Joint Source of Biosilica and Carbon for Lithium-Ion Battery Anodes
- Andrzej Nowak
- Myroslav Sprynskyy
- Izabela Wojtczak
- Konrad Trzciński
- Joanna Wysocka
- Mariusz Szkoda
- Bogusław Buszewski
- Anna Lisowska-Oleksiak
The biomass of one type cultivated diatoms (Pseudostaurosira trainorii), being a source of 3D-stuctured biosilica and organic matter—the source of carbon, was thermally processed to become an electroactive material in a potential range adequate to become an anode in lithium ion batteries. Carbonized material was characterized by means of selected solid-state physics techniques (XRD, Raman, TGA). It was shown that the pyrolysis temperature (600 °C, 800 °C, 1000 °C) affected structural and electrochemical properties of the electrode material. Biomass carbonized at 600 °C exhibited the best electrochemical properties reaching a specific discharge capacity of 460 mAh g−1 for the 70th cycle. Such a value indicates the possibility of usage of biosilica as an electrode material in energy storage applications
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Dielectric Barrier Discharge Systems with HV Generators and Discharge Chambers for Surface Treatment and Decontamination of Organic Products
- Jan Mucko
- Robert Dobosz
- Ryszard Strzelecki
The article presents applications of systems with power electronic converters, high voltage transformers, and discharge chambers used for nonthermal, dielectric barrier discharge plasma treatment of a plastic surface and decontamination of organic loose products. In these installations, the inductance of the high voltage transformers and the capacitances of the electrode sets form resonant circuits that are excited by inverters. The article presents characteristic features of the installations and basic mathematical relationships as well as the impact of individual parameters of system components. These converters with their output installations were designed, built, and tested by the authors. Some of the converters developed by the authors are manufactured and used in the industry.
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Differential analysis of dynamic immittance spectra
- Kazimierz Darowicki
- Artur Zieliński
This work presents a new approach to the analysis of immittance spectrograms of systems characterised by non-stationarity. The possibility of linking the evolution of the immittance response with changes in the parameters describing the system is achieved by introducing a spectrum in differential form. By using the above procedure, it becomes possible to separate elements with a dependence (or lack thereof) from an independent variable appearing in the dynamic electrochemical impedance method. The work illustrates the usefulness of this approach for the elementary components used to model the behaviour of electrochemical systems.
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Digital Filtering of Railway Track Coordinates in Mobile Multi–Receiver GNSS Measurements
- Andrzej Wilk
- Władysław Koc
- Cezary Specht
- Sławomir Judek
- Krzysztof Karwowski
- Piotr Chrostowski
- Krzysztof Czaplewski
- Paweł Dąbrowski
- Sławomir Grulkowski
- Roksana Licow
- Jacek Skibicki
- Mariusz Specht
- Jacek Szmagliński
The article discusses an important issue in connection with the technique of mobile Global Navigation Satellite System (GNSS) measurements of railway track coordinates, which is digital filtering performed to precisely determine railway track axes. For this purpose, a measuring technique is proposed which bases on the use of a measuring platform with a number of appropriately distributed GNSS receivers, where two of them determine the directional base vector of the platform. The receivers used in the research had high measuring frequency in the Real Time Kinematic (RTK) operating mode and enabled correction of the obtained results in post–processing. A key problem discussed in the article is the method for assessing the quality of the measurement results obtained from GNSS receivers, and their preparation for further processing making use of geometrically constrained parameters of the base vector and specialized digital filtering, among other elements, to precisely determining the track axis. The obtained results confirm the applicability of the used method of GNSS signal processing.
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Direct modulation for conventional matrix converters using analytical signals and barycentric coordinates
- Paweł Szczepankowski
- Tomasz Bajdecki
- Ryszard Strzelecki
This paper proposes the generalized direct modulation for Conventional Matrix Converters (CMC) using the concept of analytical signals and barycentric coordinates. The paper proposes a novel approach to the Pulse Width Modulation (PWM) duty cycle computing, which allows faster prototyping of direct control algorithms. The explanation of the new idea using analytical considerations demonstrating the principles of direct voltage synthesis has been presented in the article. The study concerns mainly the CMC3x3 but solutions for 3xn, 5x5, and 5x3 topologies have also been discussed. The transformation of instantaneous input voltages to analytic signals great permits for simple presenting of real input voltage conditions such as waveform type, asymmetry or other deformation like higher-order harmonics. The proposed interpolation methods allow for determining the values of PWM duty cycles using simple formulas based on the determinants of the 2nd-degree matrices. Therefore, the proposed method, which based on the barycentric coordinates, frees an algorithm from trigonometry and angles.
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Direction-of-Arrival Estimation Methods in Interferometric Echo Sounding
- Piotr Grall
- Iwona Kochańska
- Jacek Marszal
Nowadays, there are two leading sea sounding technologies: the multibeam echo sounder and the multiphase echo sounder (also known as phase-dierence side scan sonar or bathymetric side scan sonar). Both solutions have their advantages and disadvantages, and they can be perceived as complementary to each other. The article reviews the development of interferometric echo sounding array configurations and the various methods applied to determine the direction-of-arrival. “Interferometric echo sounder” is a broad term, applied to various devices that primarily utilize phase dierence measurements to estimate the direction-of-arrival. The article focuses on modifications to the interferometric sonar array that have led to the state-of-the-art multiphase echo sounder. The main algorithms for classical and modern interferometric echo sounder direction-of-arrival estimation are also outlined. The accuracy of direction-of-arrival estimation methods is dependent on the configuration of the array and external and internal noise sources. The main sources of errors, which influence the accuracy of the phase dierence measurements, are also briefly characterized. The article ends with a review of the current research into improvements in the accuracy of interferometric echo sounding and the application of the principle of interferometric in other devices.
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Disaster-Resilient Routing Schemes for Regional Failures
- Teresa Gomes
- Dorabella Santos
- Rita Girão-Silva
- Lúcia Martins
- Boro Nedic
- Matthias Gunkel
- Balázs Vass
- János Tapolcai
- Jacek Rak
Large-scale natural disasters can have a profound effect on the telecommunication services in the affected geographical area. Hence, it is important to develop routing approaches that may help in circumventing damaged regional areas of a network. This prompted the development of geographically diverse routing schemes and also of disaster-risk aware routing schemes. A minimum-cost geodiverse routing, where a minimum geographical distance value D is imposed between any intermediate element of one path and any element of the other path, is presented. Next, the problem of the calculation of a D-geodiverse routing solution which ensures a certain level of availability is tackled. An algorithm is described that either obtains a solution to that problem or the most available path pair satisfying the desired geographical distance value D—this can be useful for the specification of availability levels in Service Level Agreements. Finally, a case study is presented, in an optical network, to determine the cost increase in terminal equipment (transponders) of approaches to ensure a much larger separation of the paths (of the selected path pair), with respect to minimal length link-disjoint routing.