2023 - Repozytorium publikacji - Politechnika Gdańska

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A facile strategy for reclaiming discarded graphite and harnessing the rate capabilities of graphite anodes
- Honghong Tian
- Magdalena Graczyk-Zajac
- Dario M. De Carolis
- Chuanmu Tian
- Emmanuel III Ricohermoso
- Zhiwu Yang
- Wei Li
- Monika Wilamowska-Zawłocka
- Jan P. Hofmann
- Anke Weidenkaff
- Ralf Riedel
2023 JOURNAL OF HAZARDOUS MATERIALS
Graphite negative electrodes are unbeaten hitherto in lithium-ion batteries (LiBs) due to their unique chemical and physical properties. Thus, the increasing scarcity of graphite resources makes smart recycling or repurposing of discarded graphite particularly imperative. However, the current recycling techniques still need to be improved upon with urgency. Herein a facile and efficient hydrometallurgical process is reported to effectively regenerate aged (39.5 %, 75 % state-of-health, SOH) scrapped graphite (SG) from end-of-life lithium-ion bat- teries. Ultimately, the first cycle reversible capacity of SG1 (SOH = 39.5 %) improved from 266 mAh/g to 337 mAh/g while 330 mAh/g (98 %) remain after 100 cycles at 0.5 C. The reversible capacity for the first cycle of SG2 (SOH = 75 %) boosted from 335 mAh/g to 366 mAh/g with the capacity retention of 99.3 % after 100 cycles at 0.5 C, which is comparable with the benchmark commercial graphite. The regenerated graphites RG1 and RG2 exhibit excellent output characteristics even increasing the rate up to 4 C. This is the best rate level reported in the literature to date. Finally, the diffusion coefficient of Li ions during deintercalation and intercalation in the regenerated graphites have been measured by galvanostatic intermittent titration technique (GITT), determining values 2 orders-of-magnitude higher than that of the spent counterparts. Taking advantage of the synergistic effect of acid leaching and heat treatment, this strategy provides a simple and up-scalable method to recycle graphitic anodes.
A first-principles study of electronic and magnetic properties of 4d transition metals doped in Wurtzite GaN for spintronics applications
- Omkar A. Shilkar
- Rajendra Adhikari
- Subrahmanyam Sappati
- Shreya Godi
- Ashish M. Desai
2023 Pełny tekst JOURNAL OF MOLECULAR MODELING
We studied the electronic and magnetic properties of wurtzite GaN (w-GaN) doped with different concentrations of the 4d transition metal ions Nb, Mo, and Ru. We incorporated spin-polarized plane-wave density functional theory within an ultrasoft pseudopotential formalism. The 4d transition metals were doped at different geometrical sites to determine the geometry with the lowest total energy and the one that induced the largest magnetization. A spin-spin interaction study was performed to determine whether the doped compound was ferromagnetic or antiferromagnetic. The origin of magnetization in the transition metal-doped w-GaN compounds is due to the p-d hybridization of the nitrogen and 4d transition metals. From the bulk modulus results, we inferred that the structural integrity is preserved under compressive loads after doping w-GaN with these 4D transition metal ions. Our results indicate that these compounds can be used in spintronic applications.
A Five-Leg Three-Level Dual-Output Inverter
- Charles Odeh
- Arkadiusz Lewicki
- Marcin Morawiec
- Joseph O. Ojo
2023 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
Classical 3-level dual-output inverter, 3-L DOI, involves two similar 3-level inverters that provides a pair of 3-phase output voltages with same or different frequencies from common input voltage source. Flexibility of either operation of the constituting inverters is evident in this DOI; but total duplication of power switches is a major drawback. State of the art coupled 3-L DOIs reduce this drawback by providing series-shared power devices between the two different 3-phase output terminals. Compared with the classical 3-L DOI, these newly developed coupled 3-L DOIs involves a smaller number of power switches; however, independent operation of the constituting inverters is lost. In this brief, a 3-L DOI is proposed which involves lesser number of power devices and provides flexibility of either operation of the constituting inverters. The 3-L DOI feature hinges on the concept of parallel-common-inverter-leg representation. At the same or varying frequency mode operation, the proposed inverter can synthesize two 3-phase output voltages. Range and relation between the two modes of operations are defined for the DOI. The control strategy is based on the single triangular carrier sinusoidal pulse-width modulation perspective. Experimental results are presented that depict the DOI inverter performances.
A Formal Approach to Model the Expansion of Natural Events: The Case of Infectious Diseases
- Maria Teresa Signes-Pont
- Joan Boters Pitarch
- Julian Szymański
- Higinio Mora-Mora
2023 Parallel Processing Letters
A formal approach to modeling the expansion of natural events is presented in this paper. Since the mathematical, statistical or computational methods used are not relevant for development, a modular framework is carried out that guides from the external observation down to the innermost level of the variables that have to appear in the future mathematical-computational formalization. As an example we analyze the expansion of Covid-19. We perform a qualitative estimation of the impact of the causes on the delays of the spread and an analysis of the parameters.
A framework estimating the minimum sample size and margin of error for maritime quantitative risk analysis
- Romanas Puisa,
- Przemysław Krata
- Jakub Montewka
2023 Pełny tekst RELIABILITY ENGINEERING & SYSTEM SAFETY
The average accident frequency is essential for quantitative risk analysis and is conventionally estimated from accident statistics. This paper has systematically synthesised the knowledge on statistical errors and offered the missing instructions, a framework, for determining the minimum sample size and the margin of error (MOE) when calculating the average accident frequency from an accident database at hand. We have applied this framework to representative accident datasets in the maritime domain and presented the revealing results that can already be used in QRAs based on these datasets. The findings are useful to both QRA analysts and policy makers. Interestingly, the framework application has revealed that the determined minimum sample sizes would exceed the datasets available in existing maritime casualty databases by decades, requiring at least 10% MOE to be factored into pertinent QRAs. By the same token, the earlier notable QRAs (developed as part of formal safety assessments in support of rule making) had to consider the MOE of over 30%, given the sample sizes used, likely shifting the conclusions they arrived at. Other findings of the application have shown that the average accident frequencies for large passenger ships have remained constant over the past 40 years.
A framework of open government data (OGD) e-service quality dimensions with future research agenda
- Charalampos Harris Alexopoulos
- Stuti Saxena
- Nina Rizun
- Shao Deo
2023 Pełny tekst Records Management Journal
Purpose This research paper aims to present a framework of open government data (OGD) relating to e-service quality dimensions. In addition, it provides a research agenda for the e-service delivery of OGD. Design/methodology/approach A literature review pertaining to e-service quality with special reference to e-government was delivered to deduce the key dimensions of e-service quality for OGD. Findings Five e-service quality dimensions of OGD are identified in the study; website design, fulfilment, service provision to the user while interfacing with the OGD Web portal, service provision to the user during and after the value-creation and innovation period and security/privacy. To further OGD re-use for value creation and innovation, it is important that the e-service quality dimensions are built into all OGD programmes by public authorities. Originality/value Hitherto, extant research has focused on the data quality dimensions of OGD, but the dimensions linked with e-service have not been explored. This study seeks to fill this gap and, in addition, suggests further research requirements in this field.
A Generalized Version of the Lions-Type Lemma
- Magdalena Chmara
2023 Pełny tekst Annales Mathematicae Silesianae
In this short paper, I recall the history of dealing with the lack of compactness of a sequence in the case of an unbounded domain and prove the vanishing Lions-type result for a sequence of Lebesgue-measurable functions. This lemma generalizes some results for a class of Orlicz–Sobolev spaces. What matters here is the behavior of the integral, not the space
A Generative Approach to Hull Design for a Small Watercraft
- Artur Karczewski
- Janusz Kozak
2023 Pełny tekst Polish Maritime Research
In the field of ocean engineering, the task of spatial hull modelling is one of the most complicated problems in ship design. This study presents a procedure applied as a generative approach to the design problems for the hull geometry of small vessels using elements of concurrent design with multi-criteria optimisation processes. Based upon widely available commercial software, an algorithm for the mathematical formulation of the boundary conditions, the data flow during processing and formulae for the optimisation processes are developed. As an example of the application of this novel approach, the results for the hull design of a sailing yacht are presented.
A hybrid approach to optimization of radial inflow turbine with principal component analysis
- Łukasz Witanowski
- Paweł Ziółkowski
- Piotr Klonowicz
- Piotr Lampart
2023 ENERGY
Energy conversion efficiency is one of the most important features of power systems as it greatly influences the economic balance. The efficiency can be increased in many ways. One of them is to optimize individual components of the power plant. In most Organic Rankine Cycle (ORC) systems the power is created in the turbine and these systems can benefit from effective turbine optimization. The paper presents the use of two kinds of hybrid stochastic/deterministic methods for 3D blade shape optimization of a 10 kW single-stage radial inflow turbine (RIT) and compares the obtained results with those received from the stochastic or deterministic methods. Eight algorithms were used altogether, including one stochastic, three deterministic and four hybrid algorithms. Principal component analysis (PCA) was used to analyze the optimization process. 3D models of selected reference and optimized geometries were created to compare the differences in the obtained flow characteristics. At least two different geometries were found for which the efficiency increased by above 2 pp. (validated on refined grids). The increased efficiency was obtained over the entire investigated range of mass flow rate, with a value of the total-to-static efficiency of 90.6% at the nominal point obtained using a hybrid method.
A Low-Cost System for Far-Field Non-Anechoic Measurements of Antenna Performance Figures
- Jan Olencki
- Vorya Waladi
- Adrian Bekasiewicz
- Leifur Leifsson
2023 Pełny tekst IEEE Access
Prototype measurements are the key step in the development of antenna structures. Typically, their far-field characteristics are validated in expensive, dedicated facilities such as open range sites, or anechoic chambers. Despite being necessary for obtaining high-precision data (e.g., for device qualification), the use of costly infrastructure might not be fully justified when the main goal of measurements includes demonstration of the methodology behind determination of the performance figures of interest (e.g., for the purpose of teaching), or rough validation of the EM simulation model correctness. From this perspective, systems for far-field measurements in non-anechoic environments represent an interesting alternative to the utilization of the state-of-the-art equipment and facilities. Despite their proven usefulness, the mentioned systems are normally constructed around the expensive, laboratory-grade equipment, which contradicts the whole concept of low-cost measurements. This paper discusses a cost-efficient, mobile system for experimental validation of antennas. Its main components include the in-house developed rotary heads, an open-hardware-based vector network analyzer, and the measurements post-processing software. The cost of the system amounts to only around 3630 USD. The capabilities of the device have been demonstrated through measurements of two antenna structures. The considered performance figures include radiation pattern and single-direction gain vs. frequency. Comparisons against the measurements performed in benchmark conditions (anechoic chamber), as well as using professional network analyzer have also been provided. Furthermore, the documentation that facilitates the construction of the system components is shared in an online repository.
A mechanistically approached review upon assorted cell lines stimulated by athermal electromagnetic irradiation
- Khadijeh Askaripour
- Arkadiusz Żak
2023 Pełny tekst CELL CYCLE
The probable influence of electromagnetic irradiation on cancer treatment has been deduced from the interaction of artificial electromagnetic emissions with biological organisms. Nonetheless, the suspected health effects induced by electromagnetic-based technology imply that such a treatment may contaminate the adjacent healthy cells. Thus, gaining mechanistic insights into the problem is required to avoid athermal health hazards. To tackle that, the current review, based upon in vitro studies into assorted cell lines, depicts the alterations in physiological processes triggered by electromagnetic irradiation via addressing gene regulatory cascades. Furthermore, decisive factors in the hypothesized cause-effect linkage in terms of the cell line-associated, exposure-associated, or endpoint-associated parameters are highlighted. As a result, subcellular structures such as aberrant Ca2+ channels, rich glycocalyx charge, or high water content in cancerous cells, which have attracted a great deal of attention, can explain their higher susceptibility compared with healthy cells under irradiation. Affected by cell components or geometry, the cellular biological window correlates with the metabolic or cell cycle status and determines the irradiation that causes the maximum influence. For instance, correlations between the frequency (or intensity) of irradiation and cell excitability or between the duration of irradiation and cell doubling time are observed. There are unspecified signaling pathways such as the pathway of PPAR-γ or MAPKs, and also proteins devoid of any investigation such as p14, or S phase-related and G2 phase-related proteins. Other chains, such as the cAMP connection with mitochondrial ATP or ERK signaling, the association of Hsps releases with signaling pathways of MAPKs, or the role of different ion channels in regulating various cell processes, require further investigation.
A Monte Carlo Strategy to simulate Positrons and Positronium in biological Materials
- Małgorzata Franz
- Jan Franz
2023 Pełny tekst Bio-Algorithms and Med-Systems
We present an algorithm for Monte Carlo simulations of positron tracks in biological materials. The algorithm takes into account the cross-section data for elastic and inelastic collisions between positrons and molecules and processes like direct annihilation, ionization and positronium formation. In the case of positronium formation, the algorithm considers the interactions of positronium with molecules. The algorithm can be used to identify the processes that are responsible to determine the lifetime of the positrons and their annihilation mechanism (direct or through positronium formation).
A multi‑criteria approach to investigate spatial distribution,sources, and the potential toxicological effect of polycyclic aromatic hydrocarbons (PAHs) in sediments of urban retention tanks
- Nicole Nawrot
- Anna Pouch
- Karolina Matej-Łukowicz
- Ksenia Pazdro
- Muhammad Mohsin
- Shahabaldin Rezania
- Ewa Wojciechowska
2023 Pełny tekst ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
Bottom sediments deposited in retention tanks (RTs) located on two urban streams (Oliwski and Strzyza) in the central part of Gdansk (Poland) were analysed for polycyclic aromatic hydrocarbons’ (PAHs) content. PAHs were extracted from samples with methylene chloride, then the extracts were subjected to clean-up applying the solid phase extraction (SPE) method. Quantitative and qualitative determination of 16 PAHs was performed with the use of gas chromatography/mass spectrometry technique. A multi-dimensional approach was applied to analyse PAHs’ spatial distribution, source, and contamination status. Potential sources of PAHs were verified using isomer ratios supported by a statistical approach. The Σ16PAHs (in mg/kg d.w.) ranged from 1.95 ± 0.64 to 20.4 ± 6.8 for RTs located on the Oliwski Stream and from 0.50 ± 0.17 to 8.6 ± 2.9 for RTs located on the Strzyza Stream. PAHs detected in bottom sediments were mainly composed of 4- and 5-ring compounds. PAH isomer ratios such as Phen/Anth, Flth/Pyr, B(a)A/B(a)A + Chry, Inpy/Inpy + B(ghi)P, Flth/Flth + Pyr, Anth/Anth + Phen, and Flth/Flth + Pyr suggested delivery pathways for biomass, coal, and petroleum combustion. Petrogenic PAHs related to fuel leaks from cars were not detected. Statistical analyses confirmed traffic and heating system sources, while factor analysis (FA) pointed out the abrasion of wasting parts of vehicles. Based on threshold levels presented in sediment quality guidelines (SQGs), in most cases, PAHs were at low levels with occasional negative biological effects on organisms. Only sediments deposited in two RTs located on the Oliwski Stream presented harmful features for sediment-dwelling organisms. The risk assessment performed accordingly to the Σ16PAHs presented a moderate and high risk for biota. This study not only reflects the direct threat related to PAH content in bottom sediments, but also highlights the overall pollution of an area, considered to be a recreational part of the city (Oliwski Stream catchment). The findings of this study highlight the need to launch preventative methods to protect the area against pollution from heating system emission and traffic.
A Multifunctional Microwave Filter/Sensor Component Using a Split Ring Resonator Loaded Transmission Line
- Zahra Shaterian
- Michał Mrozowski
2023 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
This research is focused on the design and realiza2 tion of a microwave component with multifunctional filter/sensor 3 operation using a resonator-loaded transmission line (TL). It is 4 shown that while the structure acts as a bandstop filter, the 5 phase of the reflection coefficient from the loading resonator(s) 6 on a movable layer can be used for displacement sensing, thus 7 allowing for combining filtering with sensing in one device. 8 The proposed multifunctional mechanism is validated through 9 electromagnetic (EM) simulation of the structure. The concept 10 and the performance of the proposed device are further examined 11 through the fabrication and measurement of a multifunctional 12 filter/sensor component based on a microstrip TL loaded with 13 movable split ring resonators (SRRs).
A multi‐industry and cross‐country comparison of technology contribution to formal and informal knowledge sharing processes for innovativeness
- Wioleta Kucharska
- G. Scott Erickson
2023 Pełny tekst Knowledge and Process Management
The study explores the impact of organizational information technology (IT) competency on knowledge sharing, both explicit and tacit, in the context of innovativeness of products and processes. Knowledge sharing is then assessed in terms of tacit-to-explicit conversion and the impact of both types of knowledge on organizational innovation. Both process (internal) and product/service (external) innovation are included. As an extension, this IT competency to innovation framework is evaluated in context, both by nation (Poland and the United States) and by industry(IT, construction, and healthcare). The results obtained through the structural equation modeling method (sample size 2168 cases in total) exposed that IT competency dimensions matter for formal and informal knowledge-sharing processes and vary across countries and industries. For instance, in the US IT industry, IT-infrastructure,IT-knowledge, and IT-operations dimensions equally support explicit (formal) and tacit (informal) knowledge sharing. On the contrary, for the same industry in Poland, all dimensions support explicit knowledge sharing but regarding tacit knowledge sharing, only IT-knowledge supports it. Summing up the general findings, this study exposes that for tacit knowledge sharing, the critical IT-competency dimension is IT-knowledge, whereas for explicit- IT operations. Next, it clarifies that tacit knowledge sharing supports the explicit, and both are needed to introduce external innovations thanks to their significant impact on internal processes improvement.
A multithreaded CUDA and OpenMP based power‐aware programming framework for multi‐node GPU systems
- Paweł Czarnul
2023 Pełny tekst CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE
In the paper, we have proposed a framework that allows programming a parallel application for a multi-node system, with one or more GPUs per node, using an OpenMP+extended CUDA API. OpenMP is used for launching threads responsible for management of particular GPUs and extended CUDA calls allow to manage CUDA objects, data and launch kernels. The framework hides inter-node MPI communication from the programmer who can benefit from the traditional OpenMP+CUDA API in a multi-node environment. For optimization, the implementation takes advantage of the MPI THREAD MULTIPLE mode allowing: multiple threads handling distinct GPUs as well as overlapping communication and computations transparently using multiple CUDA streams. The solution allows data parallelization across available GPUs in order to minimize execution time and supports a power-aware mode in which GPUs are automatically selected for computations using a greedy approach in order not to exceed an imposed power limit. We have implemented and benchmarked three parallel applications including: finding the largest divisors; verification of the Collatz conjecture; finding patterns in vectors. These were tested on three various systems: a GPU cluster with 16 nodes, each with NVIDIA GTX 1060 GPU; a powerful 2-node system – one node with 8x NVIDIA Quadro RTX 6000 GPUs, the second with 4x NVIDIA Quadro RTX 5000 GPUs; a heterogeneous environment with one node with 2x NVIDIA RTX 2080 and 2 nodes with NVIDIA GTX 1060 GPUs. We demonstrated effectiveness of the framework through execution times versus power caps within ranges of 100-1400W, 250-3000W and 125-600W for these systems respectively as well as gains from using two versus one CUDA streams per GPU. Finally, we have shown that for the testbed applications the solution allows to obtain high speed-ups between 89.3% to 97.4% of the theoretically assessed ideal ones, for 16 nodes and 2 CUDA streams, demonstrating very good parallel efficiency.
A new anisotropic bending model for nonlinear shells: Comparison with existing models and isogeometric finite element implementation
- Eshwar J. Savitha
- Roger Sauer
2023 INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
A new nonlinear hyperelastic bending model for shells formulated directly in surface form is presented, and compared to four existing prominent bending models. Through an essential set of elementary nonlinear bending test cases, the membrane and bending stresses of each model are examined analytically. Only the proposed bending model passes all the test cases, while the other bending models either fail or only pass the test cases for small deformations. The proposed new bending model can handle large deformations and initially curved surfaces. It is based on the principal curvatures and their directions in the initial configuration, and it thus can have different bending moduli along those directions. These characteristics make it flexible in modeling a given material, while it does not suffer from the pathologies of existing bending models. Further, the bending models are compared computationally through four classical benchmark examples and one contact example. As the underlying shell theory is based on Kirchhoff–Love kinematics, isogeometric NURBS shape functions are used to discretize the shell surface. The linearization and efficient finite element implementation of the proposed new model are also provided.
A New Approach to Capacitive Sensor Measurements Based on a Microcontroller and a Three-Gate Stable RC Oscillator
- Zbigniew Czaja
2023 IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
A complete smart capacitive sensor solution basedA complete smart capacitive sensor solution based on a microcontroller was developed. This approach includes the development of both the hardware and software. The hardware part comprises an 8-bit microcontroller equipped with two timers/counters and a three-gate stable RC relaxation oscillator. The software part handles system configuration, measurement control, communication control, and data processing. Hence, the microcontroller acts as a frequency meter with an adaptive measuring time, and the relaxation oscillator generates a square wave with a frequency depending on the value of the capacitance of the sensor. The paper also proposes a calibration method that reduces the measurement range to 1 pF. The experimentally proven relative measurement errors of sensor capacitance are less than 0.012% for values smaller than 12 pF, and less than 0.0084% for values from 12 pF to 300 pF.
A new approach to cross-bonding in medium voltage cable lines
- Jacek Klucznik
2023 Pełny tekst Przegląd Elektrotechniczny
The medium voltage underground cable sheaths are usually bonded and earthed in every substation on the cable route. This results in additional power losses in the sheaths. The paper presents an idea of reducing power losses caused by sheaths cross-bonding. The idea of sheaths cross-connecting only in selected MV/LV substations is given instead of a typical solution, where sheaths cross-bonding requires installing additional joints on the cable route. It leads to a significant power losses reduction while investment cost remains low. Two cases are analysed in the paper: a theoretical simple radial network and a part of a real open-loop network. A significant power losses reduction was obtained in both cases.
A new approach to designing control of dissolved oxygen and aeration system in sequencing batch reactor by applied backstepping control algorithm
- Michał Kolankowski
- Michał Banach
- Robert Piotrowski
- Tomasz Ujazdowski
2023 Pełny tekst Acta Mechanica et Automatica
The Wastewater Treatment Plant (WWTP) is a very complex system, due to its nonlinearity, time-variance, and multiple time scales in its dynamics among others. The most important control parameter in a WWTP is the Dissolved Oxygen (DO) concentration. The tracking problem of the DO concentration is one of the most fundamental issues in biological wastewater treatment. Proper DO concentration control is necessary to achieve adequate biological conditions for microorganisms in a WWTP. Aeration is an im-portant, but expensive activity. It is performed using an aeration system, which includes blowers, pipelines and diffusers. This pa-per presents a new approach to designing a nonlinear control system for DO concentration control using an adaptive backstepping algorithm. A model of biological processes and a model of aeration system are applied for control system design. Simulation tests of the control system are performed. Very good control results were obtained. The proposed solution has proved to be effective and computationally efficient.