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Publications from the year 2022

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  • High-temperature Co-electrolysis of CO2/H2O and direct methanation over Co-impregnated SOEC. Bimetallic synergy between Co and Ni
    • Patryk Błaszczak
    • Marcin Zając
    • Agata Ducka
    • Krzysztof Matlak
    • Barbara Wolanin
    • Sea-Fue Wang
    • Anna Mandziak
    • Beata Bochentyn
    • Piotr Jasiński
    2022 Full text INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    To study the synergy between the transition metals for enhancing the electrochemical and chemical activity, a series of SOECs were modified with a small amount of Co ions, namely 1.8, 3.6, and 5.4 wt% in the reduced state. The addition of βCD into the precursor solution allowed for extremely fine dispersion of Co species across the Ni-YSZ cermet structure. The sample containing 3.6 wt% Co reached an outstanding over 2.5-times-higher concentration of CH4 in the outlet stream. At the same time, the Co greatly enhanced the electrochemical efficiency of water and CO2 co-electrolysis. Full characterization involving STXM imaging allowed for better understanding of the synergy between the Ni and Co host metal and made it possible to find the causes of the increased activity. It revealed the complexity of the substructures formed within the electrode. A novel discovery was described regarding the NiCo2O4 spinel structure subjected to the O2-TPO measurements. Despite the applied oxidizing atmosphere, the catalyst evolved oxygen at elevated temperatures in a reversible manner. The performance tests indicated the roles of both rWGS and direct electrolysis of CO2 in the electroreduction process. The addition of Co did not influence the prolonged degradation of the cell.

  • Hommage a Profesor Kazimierz Ostrowski. Pamięć obrazów.
    • Jan Buczkowski
    2022

    Impulsem do stworzenia wystawy, było przekazanie Uczelni przez córkę Profesora Kazimierza Ostrowskiego, Panią Honoratę Pilszyk, podobrazi, jakie pozostawił po sobie Mistrz. Były to płótna zagruntowane przez Artystę osobiście, gotowe do dalszej pracy, niektóre z ledwo zaczętym szkicem lub próbą pozostawionego koloru. Gdy zobaczyłem je w pracowni w Gdyni (a było to w 2015 roku), pomyślałem, że te podkłady mogłyby stać się inspiracją do stworzenia nowych prac, rodzaju symbolicznej kontynuacji, dokończenia dzieła przez innych malarzy. Przygotowanie wystawy prac namalowanych przez innych twórców, na płótnach należących do Kazimierza Ostrowskiego, było ideą intrygującą, wartą zaangażowania. Podobrazia dość szybko powędrowały nie tylko do jego absolwentów i przyjaciół, ale także artystów z innych ośrodków, przyjaciół związanych z Galerią Koło (w której prace Profesora prezentowane były na wystawie inaugurującej działalność galerii w 1995 roku). Gest ten został przyjęty z zainteresowaniem jako duże wyzwanie artystyczne. Ponieważ ilość podarowanych „Kachowych” płócien była ograniczona, wracając ponownie do pomysłu realizacji wystawy, postanowiłem ją rozszerzyć. Zaproponowałem udział w wystawie wszystkim pracownikom Wydziału Malarstwa Akademii Sztuk Pięknych w Gdańsku. Celem wystawy jest wyrażenie uznania dla twórczej postawy Kazimierza Ostrowskiego i jego artystycznych zmagań. Jest to także wyzwanie wobec historii i dziedzictwa kultury. Warto przekazywać naszą wspólną historię nowym pokoleniom, które stają się jej symbolicznymi spadkobiercami. Poprzez udział artystów różnych generacji, będziemy mogli przyjrzeć się artystycznym ideom, które mimo pokoleniowych różnic, posiadają wspólny rodowód. Istotny jest także modernistyczny rys w twórczości Profesora i jej relacja z malarstwem współczesnym. Ważną częścią projektu jest wydawnictwo, które zostanie zrealizowane po wystawie. Biorący udział w tym przedsięwzięciu artyści, będą mogli zaprezentować nie tylko swoje dzieła, ale także wspomnienia związane z Profesorem oraz refleksje odnoszące się do czasów studiów na Wydziale Malarstwa. To niecodzienne spotkanie jest dla nas wszystkich okazją, by oddać hołd Profesorowi oraz docenić Jego wiarę w sztukę i przepełnione pasją oddanie profesji malarza.

  • Hommage à Profesor Kazimierz Ostrowski. Pamięć obrazów
    • Krzysztof Wróblewski
    2022

    Impulsem do stworzenia wystawy, było przekazanie Uczelni przez córkę Profesora Kazimierza Ostrowskiego, Panią Honoratę Pilszyk, podobrazi, jakie pozostawił po sobie Mistrz. Były to płótna zagruntowane przez Artystę osobiście, gotowe do dalszej pracy, niektóre z ledwo zaczętym szkicem lub próbą pozostawionego koloru.(...) Przygotowanie wystawy prac namalowanych przez innych twórców, na płótnach należących do Kazimierza Ostrowskiego, było ideą intrygującą, wartą zaangażowania. Podobrazia dość szybko powędrowały nie tylko do jego absolwentów i przyjaciół, ale także artystów z innych ośrodków, przyjaciół związanych z Galerią Koło (w której prace Profesora prezentowane były na wystawie inaugurującej działalność galerii w 1995 roku).(...) Ponieważ ilość podarowanych „Kachowych” płócien była ograniczona, wracając ponownie do pomysłu realizacji wystawy, postanowiłem ją rozszerzyć. Zaproponowałem udział w wystawie wszystkim pracownikom Wydziału Malarstwa Akademii Sztuk Pięknych w Gdańsku. Ważny jest udział w projekcie najmłodszych pracowników Wydziału Malarstwa, którzy nie mieli okazji poznania profesora Kazimierza Ostrowskiego, znają osobę Profesora tylko z opowieści. Celem wystawy jest wyrażenie uznania dla twórczej postawy Kazimierza Ostrowskiego i jego artystycznych zmagań. Jest to także wyzwanie wobec historii i dziedzictwa kultury. (...) Poprzez udział artystów różnych generacji, będziemy mogli przyjrzeć się artystycznym ideom, które mimo pokoleniowych różnic, posiadają wspólny rodowód. Istotny jest także modernistyczny rys w twórczości Profesora i jej relacja z malarstwem współczesnym. (...) Ważną częścią projektu jest wydawnictwo, które zostanie zrealizowane po wystawie. Biorący udział w tym przedsięwzięciu artyści, będą mogli zaprezentować nie tylko swoje dzieła, ale także wspomnienia związane z Profesorem oraz refleksje odnoszące się do czasów studiów na Wydziale Malarstwa. To niecodzienne spotkanie jest dla nas wszystkich okazją, by oddać hołd Profesorowi oraz docenić Jego wiarę w sztukę i przepełnione pasją oddanie profesji malarza. Krzysztof Gliszczyński - kurator wystawy

  • Hopping or Tunneling? Tailoring the Electron Transport Mechanisms through Hydrogen Bonding Geometry in the Boron-Doped Diamond Molecular Junctions
    • Adrian Olejnik
    • Bartłomiej Dec
    • William A. Goddard III
    • Robert Bogdanowicz
    2022 Full text Journal of Physical Chemistry Letters

    Mechanisms of charge transport in molecular junctions involving hydrogen bonds are complex and remain mostly unclear. This study is focused on the elucidation of the electron transfer in a molecular device consisting of two boron-doped diamond interfaces bound with an aromatic linker and a hydrogen bonding surrogating molecule. The projected local density of states (PLODS) analysis coupled with transmission spectra and current−voltage (I−V) simulations show that hydrogen bonding through electron-donating hydroxyl groups in the aromatic linker facilitates electron transfer, while the electron-withdrawing carboxyl group inhibits electron transfer across the junction. Moreover, slight variations in the geometry of hydrogen bonding lead to significant changes in the alignment of the energy levels and positions of the transmission modes. As a result, we observe the switching of the electron transport mechanism from tunneling to hopping accompanied by a change in the shape of the I−V curves and current magnitudes. These results give important information on the tailoring of the electronic properties of molecular junctions.

  • Hotspot of human verbal memory encoding in the left anterior prefrontal cortex
    • Çağdaş Topçu
    • Victoria Marks
    • Krishnakant Saboo
    • Michał Lech
    • Petr Nejedly
    • Vaclav Kremen
    • Gregory A. Worrell
    • Michał Kucewicz
    2022 Full text EBioMedicine

    Background: Treating memory and cognitive deficits requires knowledge about anatomical sites and neural activities to be targeted with particular therapies. Emerging technologies for local brain stimulation offer attractive therapeutic options but need to be applied to target specific neural activities, at distinct times, and in specific brain regions that are critical for memory formation. Methods: The areas that are critical for successful encoding of verbal memory as well as the underlying neural activities were determined directly in the human brain with intracranial electrophysiological recordings in epilepsy patients. We recorded a broad range of spectral activities across the cortex of 135 patients as they memorised word lists for subsequent free recall. Findings: The greatest differences in the spectral power between encoding subsequently recalled and forgotten words were found in low theta frequency (3-5 Hz) activities of the left anterior prefrontal cortex. This subsequent memory effect was proportionally greater in the lower frequency bands and in the more anterior cortical regions. We found the peak of this memory signal in a distinct part of the prefrontal cortex at the junction between the Broca’s area and the frontal pole. The memory effect in this confined area was significantly higher (Tukey-Kramer test, p<0.05) than in other anatomically distinct areas. Interpretation: Our results suggest a focal hotspot of human verbal memory encoding located in the higher-order processing region of the prefrontal cortex, which presents a prospective target for modulating cognitive functions in the human patients. The memory effect provides an electrophysiological biomarker of low frequency neural activities, at distinct times of memory encoding, and in one hotspot location in the human brain.

  • Household Ability of Expenditures on Electricity and Energy Resources in the Countries That Joined the EU after 2004
    • Krystyna Gomółka
    • Piotr Kasprzak
    2022 Full text ENERGIES

    The purpose of the following article is to present the situation of the energy market from a household perspective between 2010 and 2020 in selected EU countries (the group of member states which joined EU after 2004). The selected countries when joining the EU had similar economic indicators and to some extent were similar in other macro-economic situations (personal income, unemployment rate, GDP level and annual growth). This article analyzes the past and current situation of the household ability expenditure on electricity and energy resources (petrol—eurosuper 95 and diesel and natural gas), taking into account price, tax conditions and the real possibility to purchase the analyzed energy sources (based on annual net salaries). The paper includes the conclusions and prospects for the future. The main objective of the study is to determine the ability amount of expenditure on electricity, natural gas and liquid fuels by household in the countries that joined the European Union after 2004. The specific objectives of the work include: the evolution of retail prices of energy sources in those countries and prices of electricity, natural gas and liquid fuels—petrol and diesel oil—in the research period from 2010 to 2020. The element that influences the final price, as assessed in this paper, is the share of taxes and compulsory charges imposed by the EU countries covered in this study. The result of the study presented inter alia that energy consumption structure did not change significantly, electricity prices were steadily growing in the countries under assessment, the use of liquid fuels—petrol and diesel oil—in the countries under study, grew over the study period. Furthermore, prices of fuel fluctuated over the period from 2010 to 2020 and during the COVID-19 pandemic, which broke out in March 2020, but did not cause any significant changes in the prices of energy carriers in the analyzed period, apart from the declines in the prices of eurosuper 95 and diesel.

  • How can systems thinking help us in the COVID‐19 crisis?
    • Krzysztof Zięba
    2022 Full text Knowledge and Process Management

    The COVID-19 pandemic outbreak remains one of the most influential events in the global economy over the recent years. While being primarily public health related, it has a tremendous impact on many other aspects, including business management. Many businesses were forced to introduce rapid changes to their business models in order to survive. The aim of this paper is to show the complexity and interrelations of changes triggered by COVID-19 outbreak. Understanding of this complexity is crucial for developing business resilience to similar events in the future. The paper uses systems thinking approach to analyze influence of COVID-19 pandemic on business operations and to show the importance of the proper government response to the COVID-19 crisis. A causal loop diagram is used to show the complicated mechanisms behind the impact of pandemic on several aspects of business operation and manage- ment. Perceptions of some variables play more important roles than actual variables, and it often requires more than one actor to solve a particular problem. Adaptive business management may prove to be a particular challenge for small business owners. The paper provides useful insights into the complex nature of contemporary business operation and management in the wake of a major epidemiological crisis. It may contribute to a better understanding of important factors that often tend to be disregarded and not paid enough attention to. It offers food for thought not only for academics, but also to business owners/managers, aware of the complexity of contemporary world and to government-level decision-makers.

  • How can the work environment be redesigned to enhance the well-being of individuals with autism?
    • Michał Tomczak
    2022 Full text Employee Relations

    Purpose – This article examines the opportunities to create optimal conditions for individuals with autism, to work successfully within the contemporary workplace and improve their well-being. These opportunities arise from digital technology (DT) development, enabling the work environment to be remodeled by providing new possibilities and ways of working. The author discusses both technology-based as well as non-technological accommodations supporting overcoming the workplace challenges faced by employees with autism. Design/methodology/approach – A qualitative research was conducted with the use of in-depth interviews with 21 individuals with expertise in the field. Findings – Possible technology-based work environment modifications and non-technological managerial practices facilitating work integration and the long-term well-being of individuals with autism were proposed. These solutions address four main problems: (1) effective communication; (2) time management, task prioritizing, and organization of work; (3) stress management and emotion control; and (4) sensory sensitivity. Practical implications – Proposed solutions include primarily the wide usage of electronic mediated forms of communicating based on non-direct and non-verbal contact; a flexible approach towards work organization; accurate stress monitoring systems; and an individualized approach toward office space arrangements limiting external stimuli. Originality/value – All this could lead not only to an increase in employment in individuals on the autism spectrum but also influence the improvement of the job performance of already employed. Modifications introduced could improve the long-term well-being of all employees, both with autism and neurotypical ones.

  • How does climate change affect ice formation and presence in rivers, lakes and oceans, as well as its impact on infrastructure
    • Knut Alfredsen,
    • Robert Bridges
    • Hayo Hendrikse
    • Knut Vilhelm Høyland
    • Tomasz Kolerski
    • Matti Leppäranta,
    • Lu Peng
    • Xinlei Guo,
    2022 Hydrolink

    Ice season in rivers, lakes, seas and oceans is sensitive to climate change due to the high homologous temperature. Two vital aspects of the predicted climate change are increasing average air temperature and increasing variability in the weather. These cause delayed formation of ice, thinner ice and shorter duration of seasonal ice covers, the geographical ice margin to move further away from the equator, the perennial ice to become thinner and decrease in extent, and as a result the fraction of first-year ice becomes higher. But, because of the larger weather variability, the severity of extreme events may not be reduced. In this article we discuss how ice in surface waters is affected by climate change and discuss some practical consequences for adapting our societies to these changing ice conditions.

  • How high-tech solutions support the fight against IUU and ghost fishing: a review of innovative approaches, methods, and trends
    • Zuzanna Klawikowska
    • Tomasz Ujazdowski
    • Michał Grochowski
    • Robert Piotrowski
    2022 Full text IEEE Access

    Illegal, Unreported, and Unregulated fishing is a major threat to human food supply and marine ecosystem health. Not only is it a cause of significant economic loss but also its effects have serious long-term environmental implications, such as overfishing and ocean pollution. The beginning of the fight against this problem dates since the early 2000s. From that time, a number of approaches and methods have been developed and reported. A key role in this topic is played by machine learning algorithms which exploit data provided by classical and high-tech sensors, devices and systems such as for example: CCTV, onboard cameras placed on autonomous vehicles, Global Positioning Systems, radars, Automatic Identification Systems, Vessel Monitoring Systems, or Coastal Surveillance Systems. The main objective of this paper is to provide the reader with knowledge about the scale of this phenomenon, methods to tackle the issue, and the current state of research on the subject. This has been achieved through a review of existing approaches that deal with these harmful phenomena by using dedicated artificial intelligence and machine learning tools, as well as the accompanying equipment and devices. In addition, flaws and gaps in current methods, and future directions are disscussed.

  • How non-technological innovation saved the day by using ICT
    • Julita Wasilczuk
    2022

    Certainly, the current pandemic situation provides a lot of evidence of the need for non-technological innovations, both in the area of company organization and marketing. Socio-cultural innovations are not less important. Therefore, the role of non-technological innovation during the COVID-19 pandemic is discussed in the sixth chapter. Innovations supported by digital solutions have become a silent heroes for many companies as they struggle with the consequences of the pandemic. New distribution and promotion channels allowed for the continuation of sales during the lockdown. Organizational changes in the functioning of enterprises also played an important role, primarily in the area of work that was transferred to homes. Entrepreneurs, forced to use ICT technologies, have rapidly accelerated their digital transformation. The chapter cites the results of the latest research and reports on the functioning of enterprises during the pandemic, as well as literature relating to crisis management and resilience.

  • How to Meet the Green Deal Objectives—Is It Possible to Obtain 100% RES at the Regional Level in the EU?
    • Bartłomiej Igliński
    • Michał Pietrzak
    • Urszula Kiełkowska
    • Mateusz Skrzatek
    • Artur Gajdos
    • Anas Zyadin
    • Karthikeyan Natarajan
    2022 Full text ENERGIES

    The subject matter discussed in the article concerns the problem of the energy transformation of the European Union (EU) countries. In the case of the EU, the energy transformation has specific characteristics due to formal legal and institutional provisions. This means that the member states are obliged to implement the adopted Community Energy Strategy, which was defined under the European Green Deal. According to the EU policy, all member states are to have cli-mate-neutral and zero-gas-emission economies by 2050. The energy transformation is to be largely based on the diversification of the energy sources used, with a dominance of renewable energy sources (RES). The article presents a research problem, where the question was asked whether achieving climate-neutral energy independence based solely on RES is possible at the regional level. It seems that the positive answer is an important argument in the discussion about the possibility of all member states achieving the goals set under the European Green Deal. Additionally, stating the possibility of energy independence from RES for a selected re-gion is an important argument to promote just and bottom-up initiatives in order to carry out the energy transformation more effectively. The assessment of the energy potential from re-newable sources at the regional level was carried out on the example of a selected NUTS 2 re-gion, the Greater Poland Voivodeship in Poland. The main objective of the study is to analyze the possibility of obtaining independence from RES by the selected Greater Poland Voivodeship. The implementation of the objective consists of determining the energy potential from RES in the Voivodeship under study on the basis of the methods of a geographic information system (GIS). GIS methods were selected due to the fact that they allow for the spa-tial positioning of point, line, and surface structures in relation to the potential of RES, thus en-suring high accuracy of the obtained estimates. The analysis carried out in the study shows that the technical potential of RES in the Greater Poland Voivodeship is higher than the current elec-tricity and heat usage. This means that by focusing solely on RES in the region, the Greater Po-land Voivodeship can fully meet the energy demand thanks to its green resources. It should be emphasized that the Greater Poland Voivodeship is one of the coal-dependent regions in Poland that has already prepared a structured plan of just transformation.

  • How to Sort Them? A Network for LEGO Bricks Classification
    • Tomasz Boiński
    • Konrad Zawora
    • Julian Szymański
    2022 Full text

    LEGO bricks are highly popular due to the ability to build almost any type of creation. This is possible thanks to availability of multiple shapes and colors of the bricks. For the smooth build process the bricks need to properly sorted and arranged. In our work we aim at creating an automated LEGO bricks sorter. With over 3700 different LEGO parts bricks classification has to be done with deep neural networks. The question arises which model of the available should we use? In this paper we try to answer this question. The paper presents a comparison of 28 models used for image classification trained to classify objects to high number of classes with potentially high level of similarity. For that purpose a dataset consisting of 447 classes was prepared. The paper presents brief description of analyzed models, the training and comparison process and discusses the results obtained. Finally the paper proposes an answer what network architecture should be used for the problem of LEGO bricks classification and other similar problems.

  • Human emotion recognition with biosignals
    • Wioleta Szwoch
    2022

    This chapter presents issues in the field of affective computing. Basic preliminary information for the recognition of emotions is given and models of emotions, various ways of evoking emotions, as well as their theoretical foundations are discussed. The particular attention is given to the use of physiological signals in recognizing emotions. This subject is outlined further below by presenting selected biosignals, their relationship to emotions and their use in emotion recognition. Related problems, methods and algorithms are presented and applications, along with the possible further research directions reviewed.

  • Human System Interaction in Review: Advancing the Artificial Intelligence Transformation
    • Daswin De Silva
    • Rashmika Nawaratne
    • Jacek Rumiński
    • Aleksander Malinowski
    • Milos Manic
    2022

    The industrial advancement of human society has been fundamentally driven by diverse ‘systems’ that facilitate ‘human interaction’ within physical, digital, virtual, social and artificial environments, and upon the hyper-connected layers of system-system interactions across these environments. The research and practice of Human System Interaction (HSI) has undergone exponential development due to the enhanced capabilities, increased efficiencies and decreased costs of digitalization. Primarily driven by its unique capacity for information persistence, digitalization is now leading us into a nexus of transition where HSI is being transformed by Artificial Intelligence (AI). AI has leveraged the data and information amassed by digitalization to learn, reason, predict, optimize and thereby augment both human-system interaction and system-system interaction, within and across all hyper-connected environments noted above. In this paper, we review this evolution of HSI and contribute towards its future directions by articulating the AI transformation strategy for this nexus of transition into a Human-AI-System Interaction. The paper begins with a review of HSI that focuses on developments in the past 15 years, followed by the AI transformation strategy which comprises of the primary configurations for Human-AI-System Interaction, the current capabilities of AI, a lifecycle approach for the design, development and deployment of an AI solution and the ethical implications of AI in HSI.

  • Hybrid cross-linked chitosan/protonated-proline:glucose DES membranes with superior pervaporation performance for ethanol dehydration
    • Roberto Castro-Muñoz
    • Emilia Gontarek-Castro
    • Jakub Karczewski
    • René Cabezas
    • Gastón Merlet
    • Claudio Araya-Lopez
    • Grzegorz Boczkaj
    2022 Full text JOURNAL OF MOLECULAR LIQUIDS

    This work explores a protonated L-proline:glucose (molar ratio 5:1) deep eutectic solvent (DES) in fabricating biopolymer membranes utilizing chitosan (CS). Initially, the miscibility of CS and DES to prepare homogeneous dense blend membranes has been investigated. Different techniques, such as scanning electron microscopy, contact angle (CA), atomic force microscopy (AFM), Fourier transformed infrared spectroscopy (FTIR) and swelling degree (uptake), were used to characterize the structure of the resulting membranes. Within the pervaporation performance for ethanol dehydration, Arrhenius and mass transfer analysis were analysed in detail. Interestingly, the addition of DESs provided superior performance to crosslinked CS: DES membranes compared with the ones lacking DES. Based on the morphology and properties observed, this new concept of CS-based membranes can be alternatively applied in other solvent separations requiring hydrophilic membranes.

  • Hybrid no-signaling-quantum correlations
    • Michał Banacki
    • Piotr Mironowicz
    • Ravishankar Ramanathan
    • Paweł Horodecki
    2022 Full text NEW JOURNAL OF PHYSICS

    Fundamental investigations in non-locality have shown that while the no-signaling principle alone is not sufficient to single out the set of quantum non-local correlations, local quantum mechanics and no-signaling together exactly reproduce the set of quantum correlations in the two-party Bell scenario. Here, we introduce and study an intermediate hybrid no-signaling quantum set of non-local correlations that we term HNSQ in the multi-party Bell scenario where some subsystems are locally quantum while the remaining subsystems are only constrained by the no-signaling principle. Specifically, the set HNSQ is a super-quantum set of correlations derived from no-signaling assemblages by performing quantum measurements on the trusted subsystems. We show that in contrast to the set NS of no-signaling behaviors, there exist extreme points of HNSQ in the tripartite Bell scenario that admit quantum realization. As a tool for optimization over the set HNSQ, we introduce an outer hierarchy of semi-definite programming approximations to the set following an approach put forward by Doherty–Parrilo–Spedalieri. We perform an extensive numerical analysis of the maximal violation of the facet Bell inequalities in the three-party binary input–output scenario and study the corresponding self-testing properties. In contrast to the usual no-signaling correlations, the new set allows for simple security proofs of (one-sided)-device-independent applications against super-quantum adversaries.

  • Hybrid systems using hydrodynamic cavitation/ultrasound/Fenton processes for effective treatment of wastewater
    • Vividha Landge
    • Vikas S. Hakke
    • Sneha Korpe
    • P. Venkateswara Rao
    • Shirish H. Sonawane
    • Shriram Sonawane
    • Grzegorz Boczkaj
    2022

    The present situation of rapid growth in industrialization generates complex recalcitrant pollutants that are challenging to degrade by conventional wastewater treatment processes. The new generation pollutants such as non-metals in cosmetics or household cleaning chemicals and radioactive compounds which are recalcitrant are the emerging threat to the ecosystem. The headstrong micro and macro pollutants present in wastewater are found to be very difficult to mineralize. The known chemical & biological treatments have a limited range of applicability. The conventional methods such as mechanical agitation, coagulation, filtration, sedimentation, etc. are all time and energy-consuming processes. Energy intensive processes the exploitation of emerging technologies like sonocatalysis, photocatalysis, advanced oxidation processes in combination with cavitation (either ultrasonic cavitation or hydrodynamic cavitation), new generation adsorbents such as hydrogel; photoactive compounds, and many more need to be explored individually or in combination to get the end-to-end solution on the wastewater problem. The need for the hybrid system which is technically & economically feasible for getting efficient pollutant separation from the effluents is a colossal requirement. The chapter includes a representation of some of the attempts made to develop hybrid wastewater treatment. The combination of conventional methods such as the adsorption process in assistance with cavitation and the Fenton process to improve the removal efficiency is described with case studies. The chapter includes the case studies of wastewater treatment using the individual and combined effects of all three methods for wastewater treatment. The efficiency and effectiveness of the process have been discussed followed by the future scope & potential application of the process.

  • Hybridized Space-Vector Pulsewidth Modulation for Multiphase Two-Level Voltage Source Inverter
    • Arkadiusz Lewicki
    • Charles Ikechukwu Odeh
    • Dmytro Kondratenko
    • Marcin Morawiec
    2022 Full text IEEE TRANSACTIONS ON POWER ELECTRONICS

    In space vector pulsewidth modulation (SVPWM) algorithms for multiphase two-level voltage source inverters (VSI), the components of active vectors in all orthogonal spaces have to be calculated within the processor and stored in its memory. These necessitate intensive computational efforts of the processor and large memory space. This article presents a hybridized SVPWM for multiphase two-level VSI. In this algorithm, elements of the vector coefficient inverse matrix are calculated once outside the inverter processor and treated as constant values; this reduces the computational efforts of the processor and memory space. This scheme reverses the computational steps used in classical SVPWM. Arbitrarily pre-selected active vectors (for any position and amplitude of the reference vectors) with durations determined using classical SVPWM concept are utilized. The durations of switching vectors are analyzed and the switching sequences in individual inverter phases are optimized to reduce the number of commutations. This approach demonstrates that resignation from classical analytical method in multiphase two-level VSI enables the creation of simplified modulation algorithm. This modulation strategy enables an independent generation of multiple output voltage vectors with independent rotating speed, lengths, and positions. Experimental validation of the algorithm was carried out on two-level five-phase VSI with RL load.

  • Hybrydowa koncepcja łagodzenia stromości zmian napięcia du/dt dla wielopoziomowych przekształtników kaskadowych SiC
    • Marek Adamowicz
    • Janusz Szewczyk
    • Zbigniew Krzemiński
    2022

    W referacie zaproponowano nową hybrydową koncepcję łagodzenia stromości zmian napięcia du/dt w wielopoziomowych przekształtnikach kaskadowych SiC. Proponowana koncepcja polega na wykorzystaniu nietłumionego filtra du/dt, podatnego na rezonans oraz zastosowaniu w algorytmie sterowania PWM dodatkowych impulsów sterujących tranzystorami SiC MOSFET, wymuszających rezonansowe przełączanie napięcia na wyjściu filtra. Efekt zmniejszenia stromości du/dt w przekształtniku wielopoziomowym uzyskuje się przy wykorzystaniu pojedynczego filtra du/dt, wspólnego dla całej gałęzi fazowej, co pozwala uzyskać kompaktową konstrukcję całego przekształtnika.