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Shoreline Extraction Based on LiDAR Data Obtained Using an USV
- Armin Halicki
- Mariusz Specht
- Andrzej Stateczny
- Cezary Specht
- Oktawia Lewicka
2023 Pełny tekst TransNav - The International Journal on Marine Navigation and Safety of Sea Transportation
This article explores the use of Light Detection And Ranging (LiDAR) derived point clouds to extract the shoreline of the Lake Kłodno (Poland), based on their geometry properties. The data collection was performed using the Velodyne VLP‐16 laser scanner, which was mounted on the HydroDron Unmanned Surface Vehicle (USV). A modified version of the shoreline extraction method proposed by Xu et al. was employed, comprising of the following steps: (1) classifying the point cloud using the Euclidean cluster extraction with a tolerance parameter of 1 m and min. cluster size of 10,000 points, (2) further filtration of boundary points by removing those with height above 1 m from the measured elevation of water surface, (3) manual determination of a curve consisting of 5 points located along the entire shoreline extraction region at a relatively constant distant from the coast, (4) removal of points that are further from the curve than the average distance, repeated twice. The method was tested on the scanned section of the lake shoreline for which Ground Control Points (GCP) were measured using a Global Navigation Satellite System (GNSS) Real Time Kinematic (RTK) receiver. Then, the results were compared to the ground truth data, obtaining an average position error of 2.12 m with a standard deviation of 1.11 m. The max error was 5.54 m, while the min. error was 0.41 m, all calculated on 281 extracted shoreline points. Despite the limitations of this parametric, semi‐supervised approach, those preliminary results demonstrate the potential for accurate shoreline extraction based on LiDAR data obtained using an USV. Further testing and optimisation of this method for larger scale and better generalisation for different waterbodies are necessary to fully assess its effectiveness and feasibility. In this context, it is essential to develop computationally efficient methods for approximating shorelines that can accurately determine their course based on a set of points.
Siedziba Instytutu Pamięci Narodowej w Bydgoszczy
- Joanna Kabrońska
2023 Pełny tekst Architektura-Murator
Instytucje odpowiedzialne za ochronę dokumentów i artefaktów uczestniczą w tworzeniu tożsamości zbiorowej, ustanawiając most łączący przeszłość, teraźniejszość i przyszłość. Owe instytucje mają swoje materialne odpowiedniki: obiekty będące ich siedzibą. Tym samym również architektura bierze udział w procesie budowy zbiorowej pamięci i tożsamości, wzmacniając autorytet instytucji poprzez swoją formę oraz ukazując i kształtując relację między zbiorowością i jednostką. Potrzebne jest stopniowe wypracowywanie odmiennego sposobu myślenia o instytucjach związanych z pamięcią i ich nowej formie, zorientowanej na przyszłość. Bydgoska siedziba IPN jest właściwym punktem wyjścia do takich rozważań.
Silica In Silico: A Molecular Dynamics Characterization of the Early Stages of Protein Embedding for Atom Probe Tomography
- Giovanni Novi Inverardi
- Francesco Carnovale
- Lorenzo Petrolli
- Simone Taioli
- Gianluca Lattanzi
2023 Pełny tekst BIOPHYSICAL JOURNAL
A novel procedure for the application of atom probe tomography (APT) to the structural analysis of biological systems, has been recently proposed, whereby the specimen is embedded by a silica matrix and ablated by a pulsed laser source. Such a technique, requires that the silica primer be properly inert and bio-compatible, keeping the native structural features of the system at hand, while condensing into an amorphous, glass-like coating. In this work, we propose a molecular dynamics protocol, aimed at depicting and characterizing the earliest stages of the embedding process of small biomolecules in a solution of water and orthosilicic acid, here, taken as a precursor of the silica matrix. Overall, we observe a negligible influence of orthosilicic acid on the behavior of stable folded systems (such as ubiquitin). Conversely, intrinsically disordered and unstable peptides are affected by the coating, the latter seemingly inhibiting the fluctuations of flexible moieties. While further scrutiny is in order, our assessment offers a first mechanistic insight of the effects of orthosilicic acid, thereby validating its use in the proposed innovative application of APT to the structural resolution of protein molecules.
Silver(I) complexes with nitrile ligands: New materials with versatile applications
- Karolina Gutmańska
- Piotr Szweda
- Marek Daszkiewicz
- Tomasz Mazur
- Konrad Szaciłowski
- Anna Ciborska
- Anna Dołęga
2023 Pełny tekst APPLIED ORGANOMETALLIC CHEMISTRY
In the present study, the structure, thermal stability, conductive properties, and antimicrobial activity of silver(I) complexes with nitrile ligands were investigated. For the construction of the materials, 2-cyanopyridine (2-cpy), 4-cyanopyridine (4-cpy), 1,2-dicyanobenzene (1,2-dcb), and 1,3-dicyanobenzene (1,3-dcb) were used in addition to the silver nitrite and nitrate. Four new compounds were isolated and structurally characterized: one molecular complex [Ag4(1,2-dcb)4(NO3)4], two 1-D coordination polymers [Ag(2-cpy)2(NO2)]∞, [Ag2(1,3-dcb)2(NO3)2]∞, and one 3-D coordination polymer [Ag(4-cpy)(NO2)]∞. The results indicate that the nitrile complexes display good antimicrobial properties against the tested bacterial and fungal strains. The presence of weakly coordinating CN groups increases the release of silver ions into the bacterial and yeast cell environments. Moreover, these materials exhibit unusual electrical properties in thin-layer devices. On the other hand, the nitrite and nitrate counterions give rise to the low thermal stability of the complexes.
Simple analytical method for total biogenic amines content determination in wine using a smartphone
- Kaja Kalinowska
- Wojciech Wojnowski
- Marek Tobiszewski
2023 Analytical Methods
A simple, fast, and green smartphone-based procedure for total biogenic amines content determination in wine was developed and validated. Sample preparation and analysis were simplified to make the method suitable for routine analyses even in resource-scarce settings. The commercially available S0378 dye and smartphone-based detection were used for this purpose. The developed method has satisfactory figures of merit for putrescine equivalent determination with R2 of 0.9981. The method's greenness was also assessed using the Analytical Greenness Calculator. Samples of Polish wine were analysed to demonstrate the applicability of the developed method. Finally, results obtained with the developed procedure were compared with those previously obtained with GC-MS in order to evaluate the equivalence of the methods.
Simple colorimetric copper(II) sensor – spectral characterization and possible applications
- Błażej Galiński
- Jarosław Chojnacki
- Ewa Wagner-Wysiecka
2023 SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
New o-hydroxyazocompound L bearing pyrrole residue was obtained in the simple synthetic protocol. The structure of L was confirmed and analyzed by X-ray diffraction. It was found that new chemosensor can be successfully used as copper(II) selective spectrophotometric regent in solution and can be also applied for the preparation of sensing materials generating selective color signal upon interaction with copper(II). Selective colorimetric response towards copper(II) is manifested by a distinct color change from yellow to pink. Proposed systems were effectively used for copper(II) determination at concentration level 10-8 M in model and real samples of water.
Simulation Environment in Python for Ship Encounter Situations
- Lukasz Stolzmann
- Joanna Szłapczyńska
2023 Pełny tekst TransNav - The International Journal on Marine Navigation and Safety of Sea Transportation
To assess the risk of collision in radar navigation distance-based safety measures such as Distance at the Closest Point of Approach and Time to the Closest Point of Approach are most commonly used. Also Bow Crossing Range and Bow Crossing Time measures are good complement to the picture of the meeting situation. When ship safety domain is considered then Degree of Domain Violation and Time to Domain Violation can be applied. This manuscript provides a description of a ship encounter simulation software tool written in Python accompanied by a case study, implementing all the measures mentioned above. It offers a radar-like Graphical User Interface (GUI), is able to track AIS-based traffic or encounter scenarios stored in local files. The tool features several additional functions e.g. Variable Range Marker (VRM) or Electronic Bearing Line (EBL). The simulator might be a test sandbox for advanced collision avoidance algorithms.
Simulations of high-pressure fluid flow in a pre-cracked rock specimen composed of densely packed bonded spheres using a 3D CFD model and simplified 2D coupled CFD-DEM approach
- Rezvan Abdi
- Marek Krzaczek
- Andrzej Tejchman-Konarzewski
2023 POWDER TECHNOLOGY
W artykule zastosowano dwa różne podejścia do opisu jednofazowego przepływu płynu w wstępnie spękanej próbce skały o niskiej porowatości pod wysokim ciśnieniem. Głównym celem pracy było bezpośrednie porównanie rozkładu ciśnień, gęstości i prędkości płynów we wstępnie pękniętej próbce. Zachowanie próbki imitującej skałę zostało opisane przez gęsto upakowane połączone kohezją kulki z nakładającymi się na siebie elementami. Pierwsze podejście polegało na symulacji trójwymiarowego turbulentnego przepływu ściśliwego płynu w domenie ciągłej między nieruchomymi kulami. W modelu wykorzystano metodę objętości skończonych (FVM) do rozwiązania równań Naviera-Stokesa uśrednionych przez Reynoldsa i podstawowych równań modelu naprężeń Reynoldsa (BSL). Drugie podejście polegało na zastosowaniu sprzężonego modelu 2D DEM-CFD, które symulowało laminarny przepływ płynu w sieci złożonej z kanałów w obszarze ciągłym między swobodnymi kulami. Układ kul był taki sam w obu podejściach. Uzyskano podobne rozkłady ciśnienia i gęstości płynów oraz masowe natężenia przepływu płynu. Jednak prędkości płynu i jego linie przepływu były nieco inne. Pomimo uproszczonego modelu przepływu płynu, podejście 2D DEM-CFD wystarczająco dokładnie opisało przepływ płynu we wstępnie pękniętych połączonych kohezją próbkach ziarnistych przy ogromnej redukcji czasu symulacji.
Single-Slope ADC With Embedded Convolution Filter for Global-Shutter CMOS Image Sensors
- Miron Kłosowski
- Yichuang Sun
- Waldemar Jendernalik
- Grzegorz Blakiewicz
- Jacek Jakusz
- Stanisław Szczepański
2023 IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS
This brief presents an analog-to-digital converter (ADC) suitable for acquisition and processing of images in the global-shutter mode at the pixel level. The ADC consists of an analog comparator, a multi-directional shift register for the comparator states, and a 16-bit reversible binary counter with programmable step size. It works in the traditional single-slope mode. The novelty is that during each step of the reference ramp, neighboring pixels can exchange status information. During the conversion, the direction and step size of the counter are set globally to realize the corresponding coefficient of a convolution kernel. This technique does not slow down the conversion when used for small kernels (3×3) and does not significantly increase sensor noise. Convolution windows of arbitrary size can be implemented. The concept was verified in an experimental 64×64 imaging array implemented in 180 nm CMOS technology.
Singlet oxygen in the removal of organic pollutants: An updated review on the degradation pathways based on mass spectrometry and DFT calculations
- Manoj P Rayaroth
- Usha K. Aravind
- Grzegorz Boczkaj
- Charuvila T. Aravindakumar
2023 CHEMOSPHERE
The degradation of pollutants by a non-radical pathway involving singlet oxygen (1O2) is highly relevant in advanced oxidation processes. Photosensitizers, modified photocatalysts, and activated persulfates can generate highly selective 1O2 in the medium. The selective reaction of 1O2 with organic pollutants results in the evolution of different intermediate products. While these products can be identified using mass spectrometry (MS) techniques, predicting a proper degradation mechanism in a 1O2-based process is still challenging. Earlier studies utilized MS techniques in the identification of intermediate products and the mechanism was proposed with the support of theoretical calculations. Although some reviews have been reported on the generation of 1O2 and its environmental applications, a proper review of the degradation mechanism by 1O2 is not yet available. Hence, we reviewed the possible degradation pathways of organic contaminants in 1O2-mediated oxidation with the support of density functional theory (DFT). The Fukui function (FF, f−, f+, and f0), HOMO–LUMO energies, and Gibbs free energies obtained using DFT were used to identify the active site in the molecule and the degradation mechanism, respectively. Electrophilic addition, outer sphere type single electron transfer (SET), and addition to the hetero atoms are the key mechanisms involved in the degradation of organic contaminants by 1O2. Since environmental matrices contain several contaminants, it is difficult to experiment with all contaminants to identify their intermediate products. Therefore, the DFT studies are useful for predicting the intermediate compounds during the oxidative removal of the contaminants, especially for complex composition wastewater.
Skalowalne modele fizyczne wybranych typów siłowni wiatrowych w technologii hardware-in-the-loop
- Robert Rink
2023 Pełny tekst
Celem niniejszej rozprawy jest opracowanie adekwatnego programowalnego modelu fizycznego siłowni wiatrowej wykorzystującego urządzenia elektryczne oraz model przetwarzania energii kinetycznej wiatru na energię mechaniczną ruchu obrotowego wirnika generatora. Zaproponowany przez autora model sterowany jest przez regulator prędkości, bazujący jedynie na pomiarach prędkości obrotowej oraz momentu elektromagnetycznego. Monografia stanowi syntezę aktualnego stanu wiedzy dotyczącej modeli matematycznych oraz sposobów modelowania turbin wiatrowych. Studia i analiza obecnego stanu wiedzy w zakresie przedmiotu pracy objęły stosowane sposoby realizacji modeli fizycznych oraz symulacyjnych siłowni wiatrowej i jej poszczególnych elementów oraz analizę publikowanych wyników przeprowadzonych prac badawczych z wykorzystaniem modeli fizycznych. Przeprowadzona analiza pozwoliła na zidentyfikowanie wad i ograniczeń dotychczasowych realizacji. W konsekwencji, zaproponowano autorskie rozwiązanie skalowalnego modelu fizycznego siłowni wiatrowej z maszyną dwustronnie zasilaną pracującą jako generator bazując na rozwiązaniach stosowanych w technice hardware-in-the-loop. Rozwiązanie łączy uniwersalność modeli cyfrowych z wykorzystaniem urządzeń elektrycznych. W skład opracowanej cyfrowej części modelu wchodzą wszystkie elementy występujące w rzeczywistej siłowni wiatrowej. Część cyfrowa modelu zrealizowana została w środowisku czasu rzeczywistego Simulink Real-Time. Strukturę modelu opracowano w taki sposób, aby możliwa była stabilna praca modelu w sprzężeniu z przekształtnikami i zespołem maszynowym. W szczególności zaproponowano autorską metodę dostosowania stałej bezwładności maszyny dwustronnie zasilanej skalowalnego modelu fizycznego siłowni wiatrowej z modelowaniem inercji w torze sterowania momentem wraz z regulatorem prędkości. Istotnym elementem pracy jest opracowanie sposobu walidacji skalowalnego fizycznego modelu siłowni wiatrowej z maszyną dwustronnie zasilaną. Przeprowadzono badania porównawcze fizycznego modelu siłowni wiatrowej oraz referencyjnej farmy wiatrowej. Uzyskane w rozprawie wyniki badań symulacyjnych oraz testów laboratoryjnych wykazały, że zaproponowany model fizyczny siłowni wiatrowej pozwala na miarodajną oraz efektywną emulację wybranych typów rzeczywistych siłowni wiatrowych.
"SKONTEKSTOWANE. zamieszkiwanie krajobrazów", dwa tryptyki malarskie, akryl/ podobrazie płócienne, materiał video
- Agnieszka Kurkowska
2023
Poruszamy się w świecie przemieszanych znaczeń. Kierowani tradycją, doświadczeniem i intuicją przemierzamy przestrzenie odnosząc je do swojego domu. W każdy otaczający krajobraz podświadomie lub celowo wpisujemy siebie. Filtrujemy obraz, dźwięk i zapach włączając wartości niesione przez życie. Dom z marzeń, dom ze wspomnień, dom, do którego tęsknimy, nasz dom: wypełniają kadry i współtworzy historię odwiedzanych miejsc. Przedstawione obrazy to autorska próba przedstawienia sytuacji umieszczania domu w kaszubskim krajobrazie Pojezierza Wdzydzkiego. Plastyczna interpretacja wybranych miejsc łączy się z dokumentującymi fotografiami.
Skutki zanieczyszczenia środowiska związane z generowaniem energii
- Anna Dettlaff
2023
Na całym świecie (dane z 2020 roku) spalanie paliw kopalnych takich jak węgiel, ropa naftowa i gaz ziemny dostarczyło ok. 84% całej zużywanej energii pierwotnej. W przypadku Polski konwencjonalne źródła energii stanowiły ponad 93%. Gigantyczne zużycie konwencjonalnych paliw powoduje wielkie straty w środowisku, objawiające się m.in. skażeniem powietrza, które stanowi największe środowiskowe zagrożenie dla zdrowia ludzi na świecie i jest przyczyną milionów przedwczesnych zgonów i chorób. Szacuje się, że obciążenie chorobami powodowanymi przez skażenie powietrza jest porównywalne do innych globalnych zagrożeń dla zdrowia, w tym niezdrowej diety i palenia tytoniu. W tym rozdziale szczegółowo omówiono dwa zjawiska, smog i globalne ocieplenie, które stanowią środowiskowy, społeczny, ekonomiczny i zdrowotny koszt spalania paliw kopalnych.
Sliding bearings with sintered bronze bush lubricated by contaminated water with solid particles – Theoretical and experimental studies
- Wojciech Litwin
- Steffen Kropp
2023 WEAR
Sliding journal bearings lubricated with water coming directly from the environment are a solution used in shipbuilding, pumps and hydropower. However, the working fluid or surrounding water cannot always be filtered because of design limitations, which often causes the problem of premature wear of these sensitive bearings. The research conducted made it possible to assess the wear of sliding bearings lubricated with water containing solid particles of mineral origin. It has been proved that the geometry of the bearing and the relative size of the particles have a significant impact on the wear process of the tested sliding pair of sintered bronze and steel.
Soft skills among academics: Five theoretically informed lessons for current times
- Joanna Szulc
- Magdalena Toporek
- Michał Tomczak
- Małgorzata Gawrycka
2023 Pełny tekst Horyzonty Polityki
RESEARCH OBJECTIVE: The aim of this article is to provide a comprehensive examination of the role of soft skills among academics in the context of the evolving higher-education landscape. THE RESEARCH PROBLEM AND METHODS: We use a scoping review of existing literature to discuss the importance of soft skills in academia. Through critical analysis and synthesis, we identify patterns and gaps in current knowledge and develop five theoretically informed lessons to improve practice and theory. THE PROCESS OF ARGUMENTATION: A unique theoretical blending of five theories (resource-based, dynamic capabilities, cultural learning, implicit leadership, and human capital) forms the conceptual framework we used to arrive at our conclusions. RESEARCH RESULTS: Our first conclusion emphasizes that soft skills are essential for a competitive advantage in the performative culture of neoliberal academies. Second, we emphasize that updating soft skills is crucial in order to respond to the changing higher-education environment. Third, going beyond the universal view of academia as a sharply hierarchical industry, we demonstrate how building relationships with stakeholders is necessary for academic skill development. Our fourth lesson explores the implications of different evaluators’ perceptions of soft skills, highlighting the need for recognition of their value. The ultimate lesson highlights the need to invest in the skills of academics. CONCLUSIONS, INNOVATIONS, AND RECOMMENDATIONS: We consolidate existing theoretical approaches and overcome theoretical fragmentation to arrive at a comprehensive and theoretically grounded set of lessons for those interested in developing and utilizing soft skills among academics in the unique context of the ever-changing higher-education environment. We challenge the norms of neoliberal academia and call for the development of realistic policies and procedures that promote a respectful, collaborative, and sustainable higher-education environment.
Solar light driven degradation of textile dye contaminants for wastewater treatment – studies of novel polycationic selenide photocatalyst and process optimization by response surface methodology desirability factor
- Arif Nawaz
- Muhammad Atif
- Adnan Khan
- Mohsin Siddique
- Nisar Ali
- Falak Naz
- Muhammad Bilal
- Tak H. Kim
- Malwina Momotko
- Hameed Haq
- Grzegorz Boczkaj
2023 CHEMOSPHERE
The unplanned anthropogenic activities and raced industrial revolution detrimentally causes serious threat to terrestrial and aquatic life. A high discharge of wastewater from industries using dyes affects living organisms and the environment. This paper presents studies on polycationic selenides (PCS) synthesized by hydrothermal methods for photocatalytic degradation of dyes. The synthesized PCS were confirmed by various characterization techniques such as FTIR, SEM, EDX, UV/Vis, and XRD. The FTIR spectra revealed characteristic band at 843, 548 cm−1, and 417 cm−1 due to the M − Se stretching and intrinsic stretching vibrations, respectively. The optical bandgap of polycationic selenide lies in the visible light region (2.36 eV). The SEM images showed that PCS has a spherical shape with an average crystallite size of 29.23 nm calculated from XRD data using Scherer's equation. The PCS has a point of zero charge (PZC) at pH 7. The efficiency of synthesized PCS photocatalyst was confirmed in terms of its activity towards Eosin (EY) and Crystal violet (CV) dyes mineralization. The photocatalytic degradation for EY and CV dyes at optimum conditions was 99.47% and 99.31% and followed second order reactions kinetics with 1.4314 and 0.551 rate constant, respectively. The polynomial quadratic model is the best-fitted response surface methodology (RSM) model having a maximum desirability factors value and significant terms, with R2 (0.9994) and adj R2 values (1.0).
Solubility of carbon dioxide in water: Some useful results for hydrate nucleation
- Jesús Algaba
- Iván M. Zerón
- José Manuel Míguez
- Joanna Grabowska
- Samuel Blazquez
- Eduardo Sanz
- Carlos Vega
- Felipe J. Blas
2023 Pełny tekst JOURNAL OF CHEMICAL PHYSICS
In this paper, the solubility of carbon dioxide (CO2) in water along the isobar of 400 bar is determined by computer simulations using the well-known TIP4P/Ice force field for water and the TraPPE model for CO2. In particular, the solubility of CO2 in water when in contact with the CO2 liquid phase and the solubility of CO2 in water when in contact with the hydrate have been determined. The solubility of CO2 in a liquid–liquid system decreases as the temperature increases. The solubility of CO2 in a hydrate–liquid system increases with temperature. The two curves intersect at a certain temperature that determines the dissociation temperature of the hydrate at 400 bar (T3). We compare the predictions with T3 obtained using the direct coexistence technique in a previous work. The results of both methods agree, and we suggest 290(2) K as the value of T3 for this system using the same cutoff distance for dispersive interactions. We also propose a novel and alternative route to evaluate the change in chemical potential for the formation of hydrates along the isobar. The new approach is based on the use of the solubility curve of CO2 when the aqueous solution is in contact with the hydrate phase. It considers rigorously the non-ideality of the aqueous solution of CO2, providing reliable values for the driving force for nucleation of hydrates in good agreement with other thermodynamic routes used. It is shown that the driving force for hydrate nucleation at 400 bar is larger for the methane hydrate than for the carbon dioxide hydrate when compared at the same supercooling. We have also analyzed and discussed the effect of the cutoff distance of dispersive interactions and the occupancy of CO2 on the driving force for nucleation of the hydrate.
Solvent influence on the crystal structures of new cadmium tri-tert -butoxysilanethiolate complexes with 1,4-bis(3-aminopropyl)piperazine: luminescence and antifungal activity
- Daria Kowalkowska-Zedler
- Piotr Bruździak
- Zbigniew Hnatejko
- Renata Łyszczek
- Anna Brillowska-Dąbrowska
- Łukasz Ponikiewski
- Bartosz Cieśla
- Agnieszka Pladzyk
2023 Pełny tekst Acta Crystallographica Section C-Structural Chemistry
Monocrystals of dinuclear 1,4-bis(3-aminopropyl)piperazine-�4N1,N10:N4,N40-bis[bis(tri-tert-butoxysilanethiolato-�S)cadmium(II)], [Cd2(C12H27O3SSi)4(C10-H24N4)] or [Cd2{SSi(OtBu)3}4(�-BAPP)], 1, and polynuclear catena-poly[[bis- (tri-tert-butoxysilanethiolato-�S)cadmium(II)]-�-1,4-bis(3-aminopropyl)piperazine-�2N10:N40], [Cd(C12H27O3SSi)2(C10H24N4)]n or [Cd{SSi(OtBu)3}2(�-BAPP)]n, 2, with 1,4-bis(3-aminopropyl)piperazine (BAPP) and tri-tert-butoxysilane-thiolate ligands, were obtained from the same ratio of reactants, but with different solvents used for the crystallization processes. The structures and properties of both complexes were characterized using elemental analysis, X-ray diffraction and FT–IR, 1H NMR and luminescence spectroscopy. Applied density functional theory (DFT) computational methods and noncovalent interaction (NCI) analysis were used for geometry optimization and visualiza- tion of the interactions between the metallic centres and their surroundings. The X-ray analysis revealed four-coordinate CdII centres bound to two S atoms of the silanethiolate groups and two N atoms of the BAPP ligand; however, it chelates to tertiary and primary N atoms in 1, whilst in 2 it does not chelate and bonds only to RNH2. The photoluminescence properties of complexes 1 and 2 result from free-ligand emission and differ significantly from each other with respect to emission intensity. Additionally, antifungal activity was investigated against 18 isolates of fungi. Compound 1 strongly inhibited the growth of three dermatophytes: Epidermophyton floccosum, Microsporum canis and Trichophyton rubrum.
Sources of contamination in sediments of retention tanks and the influence of precipitation type on the size of pollution load
- Karolina Matej-Łukowicz
- Ewa Wojciechowska
- Tomasz Kolerski
- Nicole Nawrot
- Karol Kuliński
- Aleksandra Winogradow
2023 Pełny tekst Scientific Reports
Densification of cities and urban population contributes to increased runoff and suspended solids and alteration of the urban water cycle. Nowadays, Blue-Green Infrastructure is promoted to increase a city’s resilience to floods; however, stormwater drainage systems, supported with retention tanks are still important in protecting urban areas against floods. Sediment accumulation in stormwater infrastructure relates to an issue of pollutants such as heavy metals, nutrients etc. Research on the origin of the pollutants associated with the suspension and ultimately sediment accumulated in sewage can bring new insights about processes in urban catchment areas. This is the first study, which is focused on the analysis of stable carbon and nitrogen isotopes in bottom sediments collected from municipal retention tanks to verify the origin of the deposited pollutants immediately after pluvial floods. The research was additionally extended with water quality analyzes immediately after three types of weather: a dry period, typical precipitation (< 30 mm) and torrential rainfalls (2 events with daily precipitation over 30 mm which caused pluvial flooding of the city area). Analyses of sediments indicated that the main source of carbon and nitrogen in the bottom of the retention tanks had been brought with stormwater runoff from the city area. Organic nitrogen fertilizers appeared to be the main source of nitrogen, while the sources of organic carbon were mixed: C3 land plants, wood, and oil. Additionally, it was found that torrential rainfall caused a 23-fold increase of N-NO3 concentration, a sevenfold increase of P-PO4 concentration, and an over fivefold increase of concentration of organic matter, in comparison to typical precipitation.
Space Vector Pulsewidth Modulation Strategy for Multilevel Cascaded H-Bridge Inverter With DC-Link Voltage Balancing Ability
- Arkadiusz Lewicki
- Charles Odeh
- Marcin Morawiec
2023 Pełny tekst IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS
Space vector pulsewidth modulation (SVPWM) algorithms for cascaded H-bridge multilevel (CHB ML) inverter usually provide the possibility of using several combinations of active voltage vectors to generate the same output voltage vector. For preselected H-bridges, some of them may generate output voltages opposite to the assumed direction. This results in the change of the dc-link voltages of these H-bridges in the opposite direction to the assumed direction in the ordering algorithm. Consequently, these algorithms are characterized by undue constraints and narrow possibilities of dc-link voltage balancing. In the proposed control algorithm, CHB ML inverter is treated as groups of successively activated three-level inverters; depending on the length of the reference voltage vector. These three-level inverters consist of three H-bridges selected from each phase. The proposed extended selection method enables firm-grip control of the dc-link voltages. For a given direction of phase currents, the possibility of using H-bridges with lowest and highest dc-link voltages is simultaneously analyzed. Additionally, each of the three-level inverters is controlled by one of three proposed alternative modulation methods for which both the attainable output voltage vectors and unbalanced dc-link voltages are predicted. Simulation and experimental results confirm the correctness of the algorithm execution.