2024 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2024

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Modified GAPI (MoGAPI) Tool and Software for the Assessment of Method Greenness: Case Studies and Applications
- Fotouh R. Mansour
- Justyna Płotka-Wasylka
- Marcello Locatelli
2024 Analytica
The green analytical procedure index (GAPI) has been widely used to assess the greenness of different steps in analytical methodology. In the GAPI index, the different stages of the chemical analysis process are depicted using five pentagrams divided in subsections, labeled green, yellow, or red according to the degree of greenness. This GAPI tool provides a quick overview of the environmental impact and safety of the procedure. However, there is no total score that can be calculated from the GAPI metric to enable comparison between methods. In this work, a modified GAPI tool (MoGAPI) and software have been developed and applied to address the limitations of the current GAPI metric. The presented tool offers a more precise assessment of greenness, while the software simplifies and expedites its application. It also combines the advantages of the analytical Eco-Scale with the merits of the widely used GAPI metric. This tool was successfully applied to calculate the greenness of a few case studies and applications to show the applicability of this modified metric. The software for the MoGAPI tool is also freely available (open source) at bit.ly/MoGAPI to facilitate application and method comparison. The MoGAPI tool and its software represent a significant advancement in greenness assessment, providing researchers with a robust and user-friendly means to evaluate and compare analytical methods.
Modified sliding mode control for seamless integration of P.V. energy in A.C. grid
- Shoaib Shaikh
- Arsalan Muhammad Soomar
- Kifayat Ullah
- Emad A.A. Ismail
- Fuad A. Awwad
- Muhammad Kamran
- Piotr Musznicki
- Syed Hadi Hussain Shah
2024 Full text Energy Reports
Solar energy is a potentially abundant and reliable source of renewable energy. While it can undoubtedly increase grid reliability and efficiency, the inverted voltage generated from PV. sources may introduce distortion into the AC. grid. The proposed control mechanism, modified sliding mode control (MSMC), can seamlessly integrate the inverter output generated by obtaining DC. voltage from the boost converter linked with the PV. output. This research confirms the validity of the proposed method by comparing its results with a similar system that is only integrated through filters and with a system with a P.I. control technique. The simulation proves the effectiveness of seamlessly integrating the Photovoltaic (PV) source into the AC. grid.
Molecular Design Using Selected Concentration Effects in Optically Activated Fluorescent Matrices
- Aneta Lewkowicz
- Katarzyna Walczewska-Szewc
- Martyna Czarnomska
- Emilia Gruszczyńska
- Mattia Pierpaoli
- Robert Bogdanowicz
- Zygmunt Gryczynski
2024 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Molecular physics plays a pivotal role in various fields, including medicine, pharmaceuticals, and broader industrial applications. This study aims to enhance the methods for producing specific optically active materials with distinct spectroscopic properties at the molecular level, which are crucial for these sectors, while prioritizing human safety in both production and application. Forensic science, a significant socio-economic field, often employs hazardous substances in analyzing friction ridges on porous surfaces, posing safety concerns. In response, we formulated novel, non-toxic procedures for examining paper evidence, particularly thermal papers. Our laboratory model utilizes a polyvinyl alcohol polymer as a rigid matrix to emulate the thermal paper’s environment, enabling precise control over the spectroscopic characteristics of 1,8-diazafluoro-9-one (DFO). We identified and analyzed the cyclodimer 1,8-diazafluoren-9-one (DAK DFO), which is a non-toxic and biocompatible alternative for revealing forensic marks. The reagents used to preserve fingerprints were optimized for their effectiveness and stability. Using stationary absorption and emission spectroscopy, along with time-resolved emission studies, we verified the spectroscopic attributes of the new structures under deliberate aggregation conditions. Raman spectroscopy and quantum mechanical computations substantiated the cyclodimer’s configuration. The investigation provides robust scientific endorsement for the novel compound and its structural diversity, influenced by the solvatochromic sensitivity of the DFO precursor. Our approach to monitoring aggregation processes signifies a substantial shift in synthetic research paradigms, leveraging simple chemistry to yield an innovative contribution to forensic science methodologies.
Molecular transformation of dissolved organic matter in manganese ore-mediated constructed wetlands for fresh leachate treatment
- Md. Hasibur Rahaman
- Tong Yang
- Zhongyi Zhang
- Wenbo Liu
- Zhongbing Chen
- Jacek Mąkinia
- Jun Zhai
2024 JOURNAL OF ENVIRONMENTAL MANAGEMENT
The organic matter (OM) and nitrogen in Fresh leachate (FL) from waste compression sites pose environmental and health risks. Even though the constructed wetland (CW) can efficiently remove these pollutants, the molecular-level transformations of dissolved OM (DOM) in FL remain uncertain. This study reports the molecular dynamics of DOM and nitrogen removal during FL treatment in CWs. Two lab-scale vertical-flow CW systems were employed: one using only sand as substrates (act as a control, CW-C) and the other employing an equal mixture of manganese ore powder and sand (experimental, CW-M). Over 488 days of operation, CW-M exhibited significantly higher removal rates for chemical oxygen demand (COD), ammonia nitrogen (NH4 +-N), and dissolved organic matter (represented by dissolved organic carbon, DOC) at 98.2 ± 2.5%, 99.2 ± 1.4%, and 97.9 ± 1.9%, respectively, in contrast to CW-C (92.8 ± 6.8%, 77.1 ± 28.1%, and 74.7 ± 9.5%). The three-dimensional fluorescence excitation-emission matrix (3D-EEM) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analyses unveiled that the influent DOM was predominantly composed of readily biodegradable protein-like substances with high carbon content and low unsaturation. Throughout treatment, it led to the degradation of low O/C and high H/C compounds, resulting in the formation of DOM with higher unsaturation and aromaticity, resembling humic-like substances. CW-M showcased a distinct DOM composition, characterized by lower carbon content yet higher unsaturation and aromaticity than CW-C. The study also identified the presence of Gammaproteobacteria, reported as Mn-oxidizing bacteria with significantly higher abundance in the upper and middle layers of CW-M, facilitating manganese cycling and improving DOM removal. Key pathways contributing to DOM removal encompassed adsorption, catalytic oxidation by manganese oxides, and microbial degradation. This study offers novel insights into DOM transformation and removal from FL during CW treatment, which will facilitate better design and enhanced performance.
Molecularly imprinted polymers based on deep eutectic solvents as a greenest materials for selective extraction of emerging contaminants from complex samples
- Mariusz Marć
- Natalia Jatkowska
- Justyna Płotka-Wasylka
- Daniel Gallart-Mateu
- Francesc A. Esteve‐turrillas
- Miguel De la Guardia
2024 TRAC-TRENDS IN ANALYTICAL CHEMISTRY
Some of the reagents applied in the synthesis of molecularly imprinted polymers (MIPs) may impact on health and the environment. Thus, a new generation of promising green chemicals are nowadays introduced and investigated, including deep eutectic solvents (DESs). DESs seems to be a reasonable choice as they are characterized as non-toxic, low cost, easy to prepare and biodegradable chemicals. This review presents the information on imprinted materials prepared using versus polymerization techniques on which DESs were applied as a more green reagents. Paper presents the benefits and roles of DESs application in the synthesis of MIPs and their potential application area such as selective and reversible sorbents/resins in analytes extraction process as well as chromatographic stationary phases. Furthermore, the specific fields of application of new type of DES-based MIPs in environmental, food and biological samples analysis are described and the future remarks in the area of DES-based MIPs are discussed.
Molecularly imprinted polymers for the detection of volatile biomarkers
- Tomasz Wasilewski
- Sinem Orbay
- Nathália F. Brito
- Karol Sikora
- Ana Claudia A. Melo
- Matias E. Melendez
- Bartosz Szulczyński
- Amitav Sanyal
- Wojciech Kamysz
- Jacek Gębicki
2024 Full text TRAC-TRENDS IN ANALYTICAL CHEMISTRY
In the field of cancer detection, the development of affordable, quick, and user-friendly sensors capable of detecting various cancer biomarkers, including those for lung cancer (LC), holds utmost significance. Sensors are expected to play a crucial role in the early-stage diagnosis of various diseases. Among the range of options, sensors emerge as particularly appealing for the diagnosis of various diseases, owing to their cost-effectiveness, simplicity, and promising analytical performance. There is growing interest in the application of molecularly imprinted polymers (MIPs) as promising recognition elements in gas sensors. MIPs, as a leading technology for sensing analytes where no suitable bioreceptor exists, are commonly used in artificial sensing that can be applied in key fields like early disease diagnostics, based on the detection of volatile biomarkers. There is an extensive demand for early, non-invasive detection of various diseases and for the self-monitoring of health conditions. Detection of biomarkers in point-of-care mode remains challenging and is limited by various factors. Hence, breath analysis has received enormous attention in healthcare due to its relatively low cost, non-invasive sampling method, and rapid detection capabilities. The latest developments in MIP-based sensors and their utility in disease diagnosis through the detection of volatile biomarkers are comprehensively and critically evaluated in this review. Furthermore, the challenges and perspectives of MIP-based sensors are elaborated upon, with a view towards introduction to the market and successful commercialization.
Molybdenum sulfide modified with nickel or platinum nanoparticles as an effective catalyst for hydrogen evolution reaction
- Mariusz Szkoda
- Daria Roda
- Malgorzata Skorupska
- Rafał Glazer
- Anna Ilnicka
2024 Scientific Reports
In this study, we investigate the catalytic performance of molybdenum sulfide (MoS2) modified with either nickel (Ni) or platinum (Pt) nanoparticles as catalysts for the hydrogen evolution reaction (HER). The MoS2 was prepared on the TiO2 nanotube substrates via a facile hydrothermal method, followed by the deposition by magnetron sputtering of Ni or Pt nanoparticles on the MoS2 surface. Structural and morphological characterization confirmed the successful incorporation of Ni or Pt nanoparticles onto the MoS2 support. Electrochemical measurements revealed that Ni- and Pt-modified MoS2 catalysts exhibited enhanced HER activity compared to pristine MoS2. Obtained catalysts demonstrated a low onset potential, reduced overpotential, and increased current density, indicating efficient electrocatalytic performance. Furthermore, the Ni or Pt-modified MoS2 catalyst exhibited remarkable stability during prolonged HER operation. The improved catalytic activity can be attributed to the synergistic effect between metal nanoparticles and MoS2, facilitating charge transfer kinetics and promoting hydrogen adsorption and desorption. Incorporating Ni and Pt nanoparticles also provided additional active sites on the MoS2 surface, enhancing the catalytic activity.
Monitoring of Ship Operations in Seaport Areas in the Sustainable Development of Ocean–Land Connections
- Mirosław Gerigk
- Jacek Jachowski
- Zbigniew Burciu
- Teresa Abramowicz-Gerigk
2024 Sustainability
The paper is devoted to underlining the important role of monitoring systems in the sustainable development of seaport areas—sensitive ocean–land connections exposed to the harmful effects of multimodal transport. The study concerns the existing monitoring possibilities of the environmental factors and ship traffic near port infrastructure. The main aim of the study is presenting the example of solutions, supporting the sustainable development of port areas, related to the most dangerous ship maneuvering operations carried out near the berths. An indirect method for measuring loads on the seabed from the propeller and thruster jets during ship berthing and an experimental method for predicting the hydrodynamic forces generated on a moored Panamax-size bulk carrier by a similar vessel passing along in shallow water conditions are described in the context of their implementation in monitoring systems. The cloud-based system—installed in the ferry terminal in the Port of Gdynia and developed for monitoring the flow generated by the ship propellers during maneuvers near the berth and warning about the exceedance of allowable pressure on the quay wall—allows, after a two-year operation, to draw the conclusions related to maintenance planning and has an impact on port sustainability. The discussion presented in the paper underlines the influence of monitoring both the environmental elements and hazardous ship operations on the sustainable development of seaport areas.
Monometallic/Bimetallic Co‐ZIFs Synthesis, Characterization, and Application for Adsorption of SO2 and CO2 in Continuous Flow System
- Sara Sumbal
- Zaheer Aslam
- Umar Irshad
- Sobia Anwar
- Aamir Abbas
- Waqar Ahmad
- Ali Hamza
2024 APPLIED ORGANOMETALLIC CHEMISTRY
Sulfur dioxide is serious ultimatum to human health as well as environment, while carbon dioxide is viewed as one of the primary drivers of the worldwide temperature alteration. Therefore, capturing of these gases is a dynamic research subject attracting much consideration from scientists. Herein, we report synthesis of a series of Co-ZIF and bimetallic M-Co-ZIF adsorbents and application for room temperature adsorption of SO2 and CO2. In this work, the breakthrough curves for the adsorption of sulfur dioxide and carbon dioxide on Co-ZIF and M-Co-ZIF were obtained experimentally and theoretically using a laboratory-scale fixed bed column at room temperature. In this work, the adsorption capacities and breakthrough points for modified bimetallic M-Co-ZIF were found to be relatively higher than parent Co-ZIF. Notably, a high SO2 uptake capacity of 7.1 mmol/g for Zr-Co-ZIF and high CO2 uptake capacity of 69.9 mmol/g for Ni-Co-ZIF were achieved. The parent cobalt and bimetallic ZIF materials were characterized by XRD, FTIR, SEM, and nitrogen physisorption. The XRD results confirm the formation of pure phase highly crystalline ZIF materials while BET analysis suggests high surface area of prepared adsorbents. Finally, the results of dynamic adsorption combined with characterization show great potential for preparation of bimetallic ZIF adsorbents for effective SO2 and CO2 adsorption.
Monte Carlo simulations of the fracture resistance of an asphalt pavement layer
- Łukasz Smakosz
- Cezary Szydłowski
- Jarosław Górski
2024 CONSTRUCTION AND BUILDING MATERIALS
The purpose of the proposed numerical model is to analyze the cracking of the wearing course in a pavement overlay, assuming a pre-existing crack that passes through the binding layer and base. The computations employed the author's simulation-based Monte Carlo material model, which describes the failure process of a Semi-Circular Bend (SCB) specimen during standard laboratory testing of asphalt concrete. A key feature of this model is the incorporation of the random nature of material parameters, allowing for the simulation of result dispersion when analyzing a sufficiently large population of samples. The proposed FEM model and obtained material data were directly applied to the numerical analysis of the pavement structure. The comprehensive computational algorithm allows for a random description of the load that induces crack propagation in the pavement wearing course, leading to the creation of a histogram that defines the range of failure load dispersion. Such supporting calculations can assist in optimizing asphalt mix design and, in the future, may allow for the estimation of pavement structure reliability.
Monte-Carlo Modeling of Optical Sensors for Postoperative Free Flap Monitoring
- Paulina Stadnik
- Ignacy Rogoń
- Mariusz Kaczmarek
2024 Full text
This work aims to develop a numerical tissue model and implement software to simulate photon propagation using the Monte Carlo method to determine design guidelines for a physical measurement system. C++ was used for the simulation program, and Python as a programming environment to create an interface that allows the user to customize individual simulation elements, allowing for increased accuracy and flexibility when simulating photon movement. This allows the user to customize the simulation to their specific requirements, ensuring the results are as accurate and reliable as possible. It also models the detector to determine if a given photon is in the desired location. The program simulates the propagation of light from a normal illumination medium with anisotropic scattering and records the escape of photons on the upper surface. The simulation also takes into account absorption and scattering coefficients for a given wavelength, and data regarding these parameters are read from a .csv file. The variance reduction technique is used to improve the efficiency of the simulation. The user interface allows users to define their own parameters, such as wavelength, anisotropy coefficient, refractive index, and layer thickness. In this paper, we simulate four photodiodes and different distances between the source and detector to determine the most suitable model for designing a physical sensor.
More than just a beer – Brewers' spent grain, spent hops, and spent yeast as potential functional fillers for polymer composites
- Aleksander Hejna
- Mateusz Barczewski
- Paulina Kosmela
- Joanna Aniśko
- Joanna Szulc
- Katarzyna Skórczewska
- Adam Piasecki
- Tairong Kuang
2024 WASTE MANAGEMENT
Beer is among the most popular beverages in the world, with the production distributed uniformly between the biggest continents, so the utilization of brewing by-products is essential on a global scale. Among their potential recipients, the plastics industry offers extensive range of potential products. Herein, the presented study investigated the application of currently underutilized solid brewing by-products (brewers' spent grain, spent hops, spent yeast) as fillers for highly-filled poly(ε-caprolactone)-based composites, providing the first direct connection between spent hops or spent yeast and the polymer composites. Comprehensive by-product characterization revealed differences in chemical composition. The elemental C:O ratio, protein content, and Trolox equivalent antioxidant capacity varied from 1.40 to 1.89, 12.9 to 32.4 wt%, and 2.41 to 10.24 mg/g, respectively, which was mirrored in the composites' structure and performance. Morphological analysis pointed to the composition-driven hydrophilicity gap limiting interfacial adhesion for high shares of brewers' spent grain and spent hops, due to high hydrophilicity induced by carbohydrate content. Phytochemicals and other components of applied by-products stimulated composites' oxidative resistance, shifting oxidation onset temperature from 261 °C for matrix over 360 °C for high spent yeast shares. Simultaneously, spent yeast also provided compatibilizing effects for poly(ε-caprolactone)-based composites, reducing complex viscosity compared to other fillers and indicating its highest affinity to poly(ε-caprolactone)due to the lowest hydrophilicity gap. The presented results indicate that the proper selection of brewing by-products and adjustment of their shares creates an exciting possibility of engineering composites' structure and performance, which can be transferred to other polymers differing with hydrophilicity.
Morphology and internal structure of small-scale washovers formed in the coastal zone of the semi-enclosed tideless basin, Gulf of Gdańsk, Baltic Sea
- D. Moskalewicz
- F. Bahr
- Łukasz Janowski
- K. Leszczyńska
- P. Sitkiewicz
- M. Słowik
- K. Stattegger
- Paweł Tysiąc
- C. Winter
2024 GEOMORPHOLOGY
This study explores the morphological features and internal structure of small-scale washovers along the southeastern Baltic Sea coast, providing insights into these most widespread yet often neglected deposits in the recent research of geomorphological and sedimentary record of storm surges. A 15-year-long record of morphological changes of the coast was acquired from regional orthophotos to analyse their geometry and spatial characteristics. Sedimentological analyses comprising a description of deposits, grain size and shape analyses, and Ground Penetrating Radar profiling were undertaken to investigate the internal structure of washovers. The formation of washovers appeared to be correlated with the average winter NAO (North Atlantic Oscillation) index. The study revealed different scaling relationships of selected spatial parameters in two coastal settings and extended previously hypothesized relationships of length-area, area-volume, and length-volume. The internal structure of washovers is defined by low-angle planar cross-stratification and horizontal stratification, both disrupted by small troughs. Grain-size data indicated extremely short transport of dune and beach sediments, lately deposited in the form of washovers. The study proves that in all domains, the geomorphological characteristics of washovers are scalable, despite the different coastal settings, and even small-scale washovers fit the existing development models
Most średnicowy w Warszawie. Koncepcja przebudowy
- Krzysztof Żółtowski
- Mikołaj Binczyk
- Przemysław Kalitowski
- Piotr Żółtowski
- Sebastian Chylewski
- Daniel Pełka
- Tomasz Jabłoński
2024 Mosty
Artykuł omawia koncepcję przebudowy Mostu Średnicowego w Warszawie, który, ze względu na zły stan techniczny i nieprzystosowanie do współczesnych wymagań, wymaga rekonstrukcji. Planowana przebudowa obejmuje wykorzystanie istniejących filarów nurtowych oraz wydłużenie mostu, co pozwoli na eliminację wiaduktów nad Wisłostradą i Wybrzeżem Szczecińskim. Przedstawiono trzy warianty konstrukcyjne: kratownicę o zmiennej wysokości, skrzynkowe przęsła blachownicowe oraz konstrukcję nawiązującą do pierwotnego projektu z lat 20. XX wieku. Analizy nośności i detali konstrukcyjnych wykonano przy użyciu zaawansowanych modeli numerycznych w środowisku MES SOFiSTiK. Ostatecznie inwestor wybrał do dalszego projektowania wariant łukowy. Prace projektowe były częścią większej modernizacji całej Linii Średnicowej w Warszawie, której realizacja ma kluczowe znaczenie dla funkcjonowania stołecznego węzła kolejowego.
MSP for port areas – To what extent should we interfere with governance of ports’ waters? Case study of Polish seaports
- Ernest Czermański
- Magdalena Matczak
- Aneta Oniszczuk-Jastrząbek
- Karolina Krośnicka
- Joanna Witkowska
2024 Full text MARINE POLICY
The EU MSP Directive imposed the requirement to develop plans for all water areas under the jurisdiction of an EU country by the end of March 2021. Poland is the only country in the Baltic Sea Region whose maritime administration has decided to elaborate detailed maritime spatial plans for port waters. The aim of the paper is to draw conclusions from the work carried out so far on the MSP for Polish port water areas. For this purpose, the drafts of the first ever plans for port areas, constituting Poland’s internal marine waters, were considered. The authors analysed planning efforts concerning Polish port water areas in two stages, quantitative and qualitative. The subjects of the analysis were the draft spatial maritime plans, prepared or in preparation, for three selected ports – Gdańsk, Szczecin and Elbląg. These study cases were chosen to represent the best variety of approaches (they were elaborated by different planning companies, having very different planning backgrounds) and were the basis for evaluating the solutions proposed in the draft plans in terms of possible interpretations of the plan’s provisions. The paper raises such questions as: What kind of functions (uses) occur while elaborating the maritime spatial plan of the port’s waters?; How are the functions distinguished within the ports’ plans interpreted by planers originating from different environments and having different types of planning experience?; How could the process of maritime spatial planning for port waters be coordinated between port authorities, maritime administration, and municipal authorities?
Multi-Analytical Techniques for the Study of Burial Clothes of Polish King Sigismund III Vasa (1566–1633) and His Wife Constance Habsburg (1588–1631)
- Magdalena Śliwka-Kaszyńska
- Maria Cybulska
- Anna Drążkowska
- Sławomir Kuberski
- Jakub Karczewski
- Anna Marzec
- Przemysław Rybiński
2024 Full text MOLECULES
The subjects of this research are the burial clothes of Polish King Sigismund III Vasa and his wife Constance, which were woven and embroidered with silk and metal threads. Fragments of the textiles underwent spectroscopic, spectrometric, and thermogravimetric analyses. The hydrofluoric acid extraction method was improved to isolate various classes of dyes from the textile samples that had direct contact with human remains. High-performance liquid chromatography, coupled with diode array and tandem mass spectrometry detectors with electrospray ionization (HPLC-DAD-ESIMS/ MS) facilitated the detection and identification of colorants present in the textiles. Cochineal, indigo-, madder-, orchil-, and tannin-producing plants were identified as the sources of dyes used. Scanning electron microscopy with an energy-dispersive X-ray detector (SEM-EDS) was employed to identify and characterize the silk fibers and mordants and the metal threads. The presence of iron, aluminum, sodium, and calcium in the silk threads suggests their potential use as mordants. The analysis of the metal threads revealed that most of them were made from flattened gilded silver wire, with only a few being cut from a sheet of metal. Typical degradation mechanisms of metal threads were shown, resulting from both burial environment and earlier manufacturing process, and the use of the textiles in clothing, i.e., a significant loss of the gold layer was observed in most of silver gilt threads, caused by abrasion and delamination. The results of the thermal analysis confirmed the presence of silk and silver threads in the examined textiles.
Multi-channel radio-over-fiber communication systems through modulation instability phenomenon
- Rasul Azizpour
- Hassan Zakeri
- Gholamreza Moradi
- Mohammad Alibakhshikenari
- Francisco Falcone
- Liu Bo
- Tayeb Dendini
- Imko Park
- Sławomir Kozieł
- Ernesto Limiti
2024 Full text IEEE Photonics Journal
Recent advancements in Radio-over-Fiber (RoF) technology have positioned it as a promising solution for highcapacity wireless communications. This paper explores novel applications of RoF systems in enhancing phased array antenna (PAA) performance for multi-channel wireless communication applications through the modulation instability (MI) phenomenon. Utilizing fibers experiencing MI with varying group velocity dispersions (β2) of -20, -11.3, -3.2, and -2 ps2/km, the RoF system achieves operational flexibility across distinct central frequencies of 12, 16, 30, and 38 GHz, respectively. This approach represents a significant advancement in wireless communication technology, leveraging MI gain and an MI-based control system architecture to enhance performance across diverse frequency bands. The study investigates the impact of MI on modulation efficiency, presenting experimental results validating the feasibility and effectiveness of the proposed approach. The maximum MI gain by employing a 30 km fiber under MI is 18 dB, experimentally. Further optimization, achieved by increasing the fiber length to 45 km and adjusting nonlinear parameters and input power, demonstrates a remarkable MI gain of 38.1 dB. MIbased true time delay (TTD) techniques also address beam squint challenges, enhancing beamforming capabilities. The findings suggest that integrating MI into RoF systems holds excellent potential for improving wireless communication capabilities with reduced costs and space requirements compared to conventional methods. This research contributes to the growing body of knowledge in the field of RoF systems and offers insights into their practical applications in modern wireless communication networks.
Multi-factor fuzzy sets decision system forecasting consumer insolvency risk
- Tomasz Korol
2024 Decision
The objective of this study is to develop a multi-factor decision system predicting insolvency risk for natural persons with the use of fuzzy sets. Considering that the financial situation of households is affected by various endogenous and exogenous factors, the main assumption of this study is that the system for predicting financial difficulties should not be limited to the use of only a few financial variables concerning consumers, but also include variables describing the environment. The author proposes a system consisting of three different forecasting models that connect the macroeconomic and microeconomic environments. It monitors the economic situation of households by also identifying those environmental variables, which may directly, or indirectly, endanger the consumer, such as unemployment rate (job market situation), inflation and interest rates, exchange rates, or economic situation in the country (GDP growth rate, the dynamics of retail sales, etc.). Moreover, the created multi-factor tool is in the form of a flexible application that can be easily adapted to changing economic conditions. Another unique feature of the study is the proposed use of newly developed ratios in household finance, similar to that in financial ratio analysis, which is commonly used in corporate finance. The proposed ratios demonstrated high predictive abilities. The paper also identifies the predictive capabilities of selected macroeconomic variables from the perspective of their impact on the risk of consumer insolvency. The research relies on four samples consisting of a total of 2,400 consumers from Taiwan and Poland. The author created three forecasting models separately for the South-East Asian and Central European regions, and two multi-factor systems, each consisting of 1260 decision rules. The findings clearly showed that a multi-factor system is a significantly more effective method compared to single forecasting models.
Multi-GPU UNRES for scalable coarse-grained simulations of very large protein systems
- Krzysztof Ocetkiewicz
- Cezary Czaplewski
- Henryk Krawczyk
- Agnieszka Lipska
- Adam Liwo
- Jerzy Proficz
- Adam K. Sieradzan
- Paweł Czarnul
2024 COMPUTER PHYSICS COMMUNICATIONS
Graphical Processor Units (GPUs) are nowadays widely used in all-atom molecular simulations because of the advantage of efficient partitioning of atom pairs between the kernels to compute the contributions to energy and forces, thus enabling the treatment of very large systems. Extension of time- and size-scale of computations is also sought through the development of coarse-grained (CG) models, in which atoms are merged into extended interaction sites. Implementation of CG codes on the GPUs, particularly the multiple-GPU platforms is, however, a challenge due to more complicated potentials and removing the explicit solvent, forcing developers to do interaction- rather than space-domain decomposition. In this paper, we propose a design of a multi-GPU coarse-grained simulator and report the implementation of the heavily coarse-grained physics-based UNited RESidue (UNRES) model of polypeptide chains. By moving all computations to GPUs and keeping the communication with CPUs to a minimum, we managed to achieve almost 5-fold speed-up with 8 A100 GPU accelerators for systems with over 200,000 amino-acid residues, this result making UNRES the best scalable coarse-grained software and enabling us to do laboratory-time millisecond-scale simulations of such cell components as tubulin within days of wall-clock time.
Multi-GPU-powered UNRES package for physics-based coarse-grained simulations of structure, dynamics, and thermodynamics of protein systems at biological size- and timescales
- Cezary Czaplewski
- Paweł Czarnul
- Henryk Krawczyk
- Agnieszka Lipska
- Emilia Lubecka
- Krzysztof Ocetkiewicz
- Jerzy Proficz
- Adam Sieradzan
- Rafał Ślusarz
- Józef Liwo
2024 BIOPHYSICAL JOURNAL
Coarse-grained models are nowadays extensively used in biomolecular simulations owing to the tremendous extension of size- and time-scale of simulations. The physics-based UNRES (UNited RESidue) model of proteins developed in our laboratory has only two interaction sites per amino-acid residue (united peptide groups and united side chains) and implicit solvent. However, owing to rigorous physics-based derivation, which enabled us to embed atomic details in the energy function, it is able to model the structures, dynamics, and thermodynamics of protein systems at good accuracy without ancillary information from structural databases. The UNRES package is an implementation of the UNRES model and uses Langevin molecular dynamics and its extensions for conformational search. It can be applied in both unrestrained simulations and those with restraints from experimental data or bioinformatics models. The package has been heavily optimized for memory and parallel performance using the message passing interface (MPI) and OpenMP libraries. Further, a GPU (graphical processor unit) and a well-scalable multiple-GPU version have been developed, thus enabling us to reach about 1 ms laboratory time in 1 day of computations for a chunk of tubulin comprising 234,260 amino-acid residues. In this communication the recent developments of the UNRES package will be presented and illustrated with appropriate examples including the simulations of (i) the dynamics of human norovirus variants, (ii) the dynamics of kinesin binding to tubulin, (iii) the conversion of thermal energy into net rotational motion by selected molecular rotatory motors, (iv) prediction of the structures of proteins and protein assemblies in recent CASP/CAPRI experiments and (iv) determination of protein structures at coarse-grained level using ambiguous NMR data. The optimized UNRES package is available from www.unres.pl and https://projects.task.gda.pl/eurohpcpl-public/unres.