2021 - Publications Repository - Gdańsk University of Technology

Show publications from the year

Publications from the year 2021

Show all

Network design for surface water quality monitoring in a road construction project using Gamma Test theory
- Sama Azadi
- Hamid Amiri
- Mehrdad Ghorbani Mooselu
- Helge Liltved
- Roberto Castro-Muñoz
- Xun Sun
- Grzegorz Boczkaj
2021 Full text Water Resources and Industry
Road construction has a negative environmental impact on the surrounding aquatic environment, requiring the continuous monitoring of surface water quality. Here, optimization of the water quality monitoring network (WQMN) is an essential step in supporting the sustainable development of road construction projects. This study introduces Gamma Test theory (GTT) as a practical method for optimizing the WQMN of surface waters during road construction. The water quality index (WQI) was computed in 48 monitoring stations for six monitoring periods from 2017 to 2019; data was acquired from a primary monitoring network over a new highway in southern Norway. Based on the results, it is possible to reduce the number of stations by 23% in comparison with the original empirical network. The proposed method could be useful to design the monitoring networks of projects with limited construction time and budget, as well as projects lacking enough data.
Neural Modelling of Steam Turbine Control Stage
- Jerzy Głuch
- Marta Drosińska-Komor
2021
The paper describes possibility of steam turbine control stage neural model creation. It is of great importance because wider application of green energy causes severe conditions for control of energy generation systems operation Results of chosen steam turbine of 200 MW power measurements are applied as an example showing way of neural model creation. They serve as training and testing data of such neural model. Relatively simple set of nozzle boxes neural models consisting control stage is applied. They act as a neural regresor. Research study on ways of creation mentioned neural model is the main purpose of the paper. Finally accurate neural tool is created. It can serve as a proper pattern of control stage operation for engineers tuning turbine control equipment. Another way of application consists in usage as a component of turbomachinery heat and flow diagnostic programs. These programs take mainly into account of technical objects efficiency degradation.
Neural Oscillation During Mental Imagery in Sport: An Olympic Sailor Case Study
- Dagmara Budnik-Przybylska
- Adrian Kastrau
- Patryk Jasik
- Maria Każmierczak
- Łukasz Doliński
- Paweł Syty
- Marta Łabuda
- Jacek Przybylski
- Selenia di Fronso
- Maurizio Bertollo
2021 Full text Frontiers in Human Neuroscience
The purpose of the current study was to examine the cortical correlates of imagery depending on instructional modality (guided vs. self-produced) using various sports-related scripts. According to the expert-performance approach, we took an idiosyncratic perspective analyzing the mental imagery of an experienced two-time Olympic athlete to verify whether different instructional modalities of imagery (i.e., guided vs. self-produced) and different scripts (e.g., training or competition environment) could differently involve brain activity. The subject listened to each previously recorded script taken from two existing questionnaires concerning imagery ability in sport and then was asked to imagine the scene for a minute. During the task, brain waves were monitored using EEG (32-channel g. Nautilus). Our findings indicate that guided imagery might induce higher high alpha and SMR (usually associated with selective attention), whereas self-produced imagery might facilitate higher low alpha (associated with global resting state and relaxation). Results are discussed in light of the neural efficiency hypothesis as a marker of optimal performance and transient hypofrontality as a marker of flow state. Practical mental training recommendations are presented.
Neurochemical changes underlying cognitive impairment in olfactory bulbectomized rats and the impact of the mGlu5-positive allosteric modulator CDPPB
- Agata Płoska
- Paulina Cieślik
- Anna Siekierzycka
- Leszek Kalinowski
- Joanna M. Wierońska
2021 BRAIN RESEARCH
The olfactory bulbectomized (OBX) rat model is a well-established model of depression in which antidepressant drugs reverse deficits in the passive avoidance test 14 days after administration. Recently, the olfactory bulbectomized rat model has been proposed to be a model of Alzheimer’s disease (AD), and the available data indicate similarities between the changes that typically occur in AD and those observed in OBX animals. In the present study, the occurrence of neurochemical impairments related to AD were investigated 8 months after OB ablation. The expression of the nitric oxide synthases eNOS and nNOS, receptor for advanced glycation endproducts (RAGEs) and dimethylarginine dimethylaminohydrolase (DDAH1) in the prefrontal cortices (PFCs), hippocampi and striata of olfactory bulbectomized and sham-operated rats was evaluated. Subsequently, the impact of the administration of a positive allosteric modulator of the mGlu5 receptor, CDPPB (14 days, 2.5 or 5 mg/kg), on OBX-related changes was assessed. OB ablation induced typical deficits in passive avoidance. Significant aberrations in the expression of both isoforms of NOS were observed in the hippocampus and striatum, and the expression of DDAH1 was increased in the PFCs of OBX animals. CDPPB at a dose of 5 mg/kg ameliorated cognitive impairment in the passive avoidance test and partially reversed the changes in eNOS and nNOS expression induced by the lesion. The results of this study confirm that some of the neurochemical changes observed in OBX animals may resemble those associated with AD pathology and that activation of the mGlu5 receptor may partially counteract these pathological alterations.
Neuronowe modele z atencją w przetwarzaniu języka naturalnego
- Szymon Olewniczak
2021
Celem niniejszego rozdziału jest wprowadzenie w tematykę sieci neuronowych z atencją oraz ich zastosowań w przetwarzaniu języka naturalnego. Rozdział skupia się w szczególności na dokładnym omówieniu architektury modelu Transformer, wykorzystującego atencję jako podstawowy mechanizm swojego działania.
Neurotrophic factors in human milk in early lactation and the effect of Holder and microwave pasteurization on their concentrations
- Dorota Martysiak-Żurowska
- Małgorzata Puta
- Bogumiła Kiełbratowska
- Aleksandra Wesołowska
2021 JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION
Objective: The objective of this study was to determine the level of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) in human milk in the first two weeks of breastfeeding and compare of the effects of Holder pasteurization (HoP, 62.5°C, 30 minutes) and microwave pasteurization (MP) at constant temperature (62.5°C) on the concentraion of both neurotrophic factors (NFs). Methods: Concentration of NFs in human milk was determined using a commercially available ELISA assay. Results: The average concentration of BDNF and GDNF in milk was 11±6 ng/mL and 336 ±238 pg/mL respectively. There was a positive correlation between the concentrations of BDNF and GDNF in human milk and day of lactation (r=0.441, p<0.05 and r=0.482, p<0.05 respectively). In addition, there was a significant correlation between the levels of BDNF and GDNF (r=0.366, p<0.05). HoP and MP for 10 minutes affected both NF levels similarly, causing degradation of BDNF by about 24% and 17%, and GDNF by 47% and 45% respectively. Use of MP for 5 minutes resulted in preservation of nearly 91% BDNF and 79% GDNF in human milk. Conclusions: In the pasteurization processes carried out, results showed that GDNF is more susceptible to degradation under the influence of high temperature. To the authors’ best knowledge, this is the first study evaluating the effects of HoP and MP at constant temperature on the concentration of NFs in human milk. It was found that the MP for 5 minutes is the optimal method.
Neutralising Responsibility: A Critical Analysis of an Airline’s Climate Disclosures
- Eljas Johansson
2021 Full text
Sustainability reporting provides companies with a medium through which they can communicate their non-financial impacts to stakeholders. The airline industry has been much at the centre of the climate change debate in recent years, which is why it is hardly surprising that airlines seek to take a proactive stance in such reporting. This study critically assesses how an airline based in the Scandinavian region constructs sustainability discourse in relation to climate impact in its corporate reporting to stakeholders. The paper uniquely approaches this question by drawing upon thematic analysis combined with an examination of the text’s grammatical meanings. Overall, the findings demonstrate that the company’s climate discourse is characterised by optimistic forward-looking statements and justifications, realised by techniques of neutralisation, whose purpose is to rationalise and legitimise the company’s adverse climate impact. This short paper contributes to the still relatively underexamined research area of airline sustainability reporting by concentrating on the climate disclosures and responding to the lack of latent analysis in this context. This paper’s findings are intended to stimulate the discussion amongst academics and practitioners on how sustainability is communicated in corporate annual reporting to make it more meaningful.
New Carvone-Based Deep Eutectic Solvents for Siloxanes Capture from Biogas
- Patrycja Makoś-Chełstowska
- Edyta Słupek
- Aleksandra Kramarz
- Jacek Gębicki
2021 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
During biogas combustion, siloxanes form deposits of SiO2 on engine components, thus shortening the lifespan of the installation. Therefore, the development of new methods for the purification of biogas is receiving increasing attention. One of the most effective methods is physical absorption with the use of appropriate solvents. According to the principles of green engineering, solvents should be biodegradable, non-toxic, and have a high absorption capacity. Deep eutectic solvents (DES) possess such characteristics. In the literature, due to the very large number of DES combinations, conductor-like screening models for real solvents (COSMO-RS), based on the comparison of siloxane activity coefficient of 90 DESs of various types, were studied. DESs, which have the highest affinity to siloxanes, were synthesized. The most important physicochemical properties of DESs were carefully studied. In order to explain of the mechanism of DES formation, and the interaction between DES and siloxanes, the theoretical studies based on σ-profiles, and experimental studies including the 1H NMR, 13C NMR, and FT-IR spectra, were applied. The obtained results indicated that the new DESs, which were composed of carvone and carboxylic acids, were characterized by the highest affinity to siloxanes. It was shown that the hydrogen bonds between the active ketone group (=O) and the carboxyl group (-COOH) determined the formation of stable DESs with a melting point much lower than those of the individual components. On the other hand, non-bonded interactions mainly determined the effective capture of siloxanes with DES.
NEW DESIGNS OF MAGNETIC FLUID SEALS FOR RECIPROCATING MOTION
- Leszek Matuszewski
- Piotr Bela
2021 Full text Polish Maritime Research
T he operating conditions of magnetic fluid seals during reciprocating motion are so different from those observed in rotating motion that the use of their conventional structures for reciprocating motion seals yields no good results. The analysis of the sealing mechanism of magnetic fluid seals in reciprocating motion shows that the operation of these seals is affected by the carry-over phenomenon and magnetic fluid film deformation in the sealing gap, which depends on the velocity of the reciprocating motion. The reduced amount of magnetic fluid in the sealing gap caused by the reciprocating motion of the shaft is the main reason for seal failures. T he paper presents a short characterisation of magnetic fluid sealing technology, the principle of sealing, the operation of the magnetic fluid and the seal failure mechanism in linear motion of the shaft. Moreover, some new structural designs of hybrid seals, being combinations of typical hydraulic seals with magnetic fluid seals for reciprocating motion, and some examples of magnetic fluid sealing structures for hydraulic cylinders and piston compressors which have practical application values are presented.
New insights on lithium storage in silicon oxycarbide/carbon composites: Impact of microstructure on electrochemical properties
- Dominik Knozowski
- Magdalena Graczyk-Zając
- Dragoljub Vrankovic
- Grzegorz Trykowski
- Mirosław Sawczak
- Dario M. De Carolis
- Monika Wilamowska-Zawłocka
2021 Full text COMPOSITES PART B-ENGINEERING
In this work, we study the impact of the preceramic precursor vinyltriethoxysilane (VTES) on the electrochemical performance of silicon oxycarbide (SiOC) glass/graphite composites. We apply an innovative approach based on high-power ultrasounds in order to obtain highly homogenous composites with a uniform distribution of small graphitic flakes. This procedure enhances gelation and drying of VTES-based preceramic polymer/graphite blends. The SiOC/graphite composites reveal stable capacities (up to 520 mAh g−1 after 270 cycles), which are much higher than the sum derived from the ratio of the components. Additionally, the first cycle Coulombic efficiencies obtained for the composites are 15% higher than that of the pristine VTES-based SiOC ceramic. These properties are identified as the synergistic effect, originated from the addition of graphite to VTES-based SiOCs. Interestingly, such improvement in electrochemical performance is not noticed in the case of analogous SiOC/graphite composites based on phenyltriethoxysilane (PhTES) precursor. The microstructural investigation of the composites based on two different preceramic precursors using solid-state 29Si NMR and Raman Spectroscopy unveils the reason for such discrepancy in their electrochemical behaviour.
New methodology for calculating cost-efficiency of different ways of voting: is internet voting cheaper?
- Robert Krimmer
- David Duenas Cid
- Iuliia Krivonosova
2021 Full text PUBLIC MONEY & MANAGEMENT
New ways of voting in elections are being sought by electoral administrations worldwide who want to reverse declining voter turnouts without increasing electoral budgets. This paper presents a novel approach to cost accounting for multi-channel elections based on local elections in Estonia. By doing so, it addresses an important gap in the academic literature in this field. The authors confirm that internet voting was most cost-efficient voting channel offered to Estonian voters. This paper presents a new, proven methodology for calculating the cost-efficiencies of various ways of voting. The authors provide rare data on electoral costs, including costs ranging from stationery to depreciation costs and provide a detailed cost breakdown of activities. The findings will have direct practical implications for electoral management bodies and policy-makers around the world.
New patterns in the position of CEE countries in global value chains: functional specialisation approach
- Aleksandra Kordalska
- Magdalena Olczyk
2021 Full text Oeconomia Copernicana
Research background: High servitisation of manufacturing makes it impossible to separate services from manufactured goods properly, which implies difficulties in the assessment of the position of the country on the smile curve, i.e. in the proper assignment of products or services to one of the industrial process steps: pre-production, pure fabrication or post-production services. Therefore, we propose to use the business functions of industries identified with the aid of labour market data rather than the industrial classification of products in order to create a more appropriate measure of the position of countries in GVCs. Purpose of the article: We aim to identify and analyse the patterns of functional specialisation for eight Central and Eastern European Countries (CEECs) ? the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia and Slovenia ? both at the country and industry level. In addition, we analyse functional specialisation patterns for Germany, which serves as a reference country. Methods: To assess functional specialisation patterns, we employ the methodology proposed by Timmer et al. (2019a). It allows us to obtain functional specialisation indices for four different business functions ? management, R&D, marketing, and fabrication. To compute them, we combine two sources of data ? domestic value added from decomposed sectoral input-output tables (the World Input Output Database) and the Occupations Database built up by Timmer et al. (2019a). Findings & value added: Our research shows a very heterogeneous pattern in CEEC countries' position in GVCs by taking into account their functional specialisation at the countries and industries levels. Poland and Slovakia focus primarily on low value-added fabrication processes, the Baltic countries and Slovenia specialise in management services, Hungary and Latvia gain in marketing services, and the Czech Republic and Slovenia win in R&D activities. We indicate that some CEE countries (Poland, Slovakia) could be stuck in a functional trap, and our approach could be a valuable tool for assessing the process of coming out of it.
New potent steroid sulphatase inhibitors based on 6-(1-phenyl-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate derivatives
- Olga Ciupak
- Mateusz Daśko
- Karol Biernacki
- Janusz Rachoń
- Maciej Masłyk
- Konrad Kubiński
- Aleksandra Martyna
- Sebastian Demkowicz
2021 Full text JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
In the present work, we report a new class of potent steroid sulphatase (STS) inhibitors based on 6-(1-phenyl-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate derivatives. Within the set of new STS inhibitors, 6-(1-(1,2,3-trifluorophenyl)-1H-1,2,3-triazol-4-yl)naphthalen-2-yl sulphamate 3L demonstrated the highest activity in the enzymatic assay inhibiting the STS activity to 7.98% at 0.5 µM concentration. Furthermore, to verify whether the obtained STS inhibitors are able to pass through the cellular membrane effectively, cell line experiments have been carried out. We found that the lowest STS activities were measured in the presence of compound 3L (remaining STS activity of 5.22%, 27.48% and 99.0% at 100, 10 and 1 nM concentrations, respectively). The measured STS activities for Irosustat (used as a reference) were 5.72%, 12.93% and 16.83% in the same concentration range. Moreover, a determined IC50 value of 15.97 nM for 3L showed that this compound is a very promising candidate for further preclinical investigations.
New Product Creativity Dimensions and Performance
- Dariusz Dąbrowski
2021 Full text
A new product’s meaningfulness and novelty are recognized as two distinct and important dimensions. Thus, researchers started to investigate their impact on new product performance. However, researchers’ reports on the impact of novelty on performance are still mixed, and several issues need to be solved. One of these problems is comparing how strongly each of these dimensions affects the new product performance. The other is to investigate the contingent influence of market turbulence on the relation between the new product’s novelty and its performance. Building on the resource-based view of the firm and signaling theory, this study aims to: 1) examine the impact of a new product’s meaningfulness and novelty on its commercial performance; 2) compare the relative influence of these dimensions on product performance; and 3) examine the moderating effect of market turbulence on the relationship between the novelty and the new product’s commercial performance. Data concerning 374 new products of Polish high- and medium-high-technology companies were examined to achieve these goals using structural equation modeling. First, the results indicated that a new product’s meaningfulness is positively related to its commercial performance, whereas novelty is not. Furthermore, meaningfulness affects performance more strongly than product novelty, and market turbulence moderates the relation between the new product’s novelty and performance. Subsequently, based on these findings, theoretical and managerial implications and directions for future research are provided.
Nieliniowa statyka 6-parametrowych powłok sprężysto plastycznych. Efektywne obliczenia MES
- Stanisław Burzyński
2021
Głównym zagadnieniem omawianym w monografii jest sformułowanie sprężysto-plastycznego prawa konstytutywnego w nieliniowej 6-parametrowej teorii powłok. Wyróżnikiem tej teorii jest występujący w niej w naturalny sposób tzw. stopień 6 swobody, czyli owinięcie (drilling rotation). Podstawowe założenie pracy to przyjęcie płaskiego stanu naprężenia uogólnionego na ośrodek typu Cosseratów. Takie podejście stanowi oryginalny aspekt opracowania. Powłokowe siły i momenty przekrojowe wyrażone są przez całki ze składowych naprężenia, co pozwala na sformułowanie nieliniowego prawa konstytutywnego dla powłoki. Zawarte w pracy rozważania teoretyczne obejmują: wyprowadzenie zlinearyzowanej zasady prac wirtualnych dla powłok, krótkie omówienie odkształceniowej teorii plastyczności, opisy liniowego ośrodka typu Cosseratów oraz funkcji plastycznego płynięcia. Zostały omówione dwa algorytmy numeryczne rozwiązywania równań plastyczności. Opisano też klasyczny algorytm MES uwzględniający nieliniowość materiałową. Osobną część monografii stanowią rozważania dotyczące efektywności obliczeń MES. Skoncentrowano się na kwestii zrównoleglenia obliczeń numerycznych oraz użyciu algorytmów rozwiązywania wielkich układów równań o rzadkiej macierzy współczynników. Celem przedstawionych technik jest skrócenie czasu trwania obliczeń numerycznych. Zwieńczenie pracy stanowią przykłady numeryczne, w których analizowane są konstrukcje powłokowe. Obliczenia przeprowadzono za pomocą autorskiego programu MES, napisanego w języku Fortran. Zaimplementowano w nim algorytmy rozwiązywania równań plastyczności oraz techniki zwiększenia efektywności obliczeń. Rozpatrywane są przykłady płaskie, powłoki cylindryczne i powłoki wielopłatowe. Stosowana w pracy teoria powłok jest w naturalny sposób przeznaczona do rozwiązywania problemów związanych z ostatnią spośród wymienionych grup. Ze względu na brak dostępnych przykładów w literaturze zaproponowano nowy przykład analizy sprężysto-plastycznej powłoki wielopłatowej. Oryginalne są również wyniki analizy stateczności powłok cylindrycznych.
Nietechnologiczne nie znaczy gorsze. Rzecz o innowacjach
- Julita Wasilczuk
- Magdalena Popowska
- Marita Mcphillips
- Magdalena Licznerska
2021 Full text
Innowacje nietechnologiczne nie zajmują istotnego miejsca w dyskursie naukowym jak i praktycznym. Zauważona luka badawcza oraz brak praktycznych rozwiązań wspierających innowacje nietechnologicznie, były motywem podjęcia tego tematu przez międzynarodowy zespół, składający się z badaczy z czterech krajów (Danii, Finlandii, Litwy i Polski) oraz szeregu instytucji wspierających biznes, w tych krajach, pełniących funkcje pośredników innowacji. W takim właśnie składzie w latach 2017-2020 realizowano projekt o wdzięcznym akronimie SNOwMAN, oznaczającym: Supporting Non-technology Innovation in Owner-managed Manufacturing czyli wsparcie nietechnologicznych innowacji w przedsiębiorstwach produkcyjnych, zarządzanych przez właścicieli, po przez stworzenie metody doradztwa . W trakcie realizacji tego projektu, okazało się, że niewiele wiadomo na temat innowacji nietechnologicznych, a zebrane materiały, doświadczenia oraz wyniki przeprowadzonych badań, mogą zostać spożytkowane w postaci monografii, która posłuży upowszechnianiu tej grupy innowacji.
Nilpotent singularities and chaos: Tritrophic food chains
- Fátima Drubi
- Santiago Ibáñez
- Paweł Pilarczyk
2021 Full text CHAOS SOLITONS & FRACTALS
Local bifurcation theory is used to prove the existence of chaotic dynamics in two well-known models of tritrophic food chains. To the best of our knowledge, the simplest technique to guarantee the emergence of strange attractors in a given family of vector fields consists of finding a 3-dimensional nilpotent singularity of codimension 3 and verifying some generic algebraic conditions. We provide the essential background regarding this method and describe the main steps to illustrate numerically the chaotic dynamics emerging near these nilpotent singularities. This is a general-purpose method and we hope it can be applied to a huge range of models.
Nitric Oxide-Dependent Pathways as Critical Factors in the Consequences and Recovery after Brain Ischemic Hypoxia
- Joanna M. Wierońska
- Paulina Cieślik
- Leszek Kalinowski
2021 Full text Biomolecules
Brain ischemia is one of the leading causes of disability and mortality worldwide. Nitric oxide (NO), a molecule that is involved in the regulation of proper blood flow, vasodilation, neuronal and glial activity constitutes the crucial factor that contributes to the development of pathological changes after stroke. One of the early consequences of a sudden interruption in the cerebral blood flow is the massive production of reactive oxygen and nitrogen species (ROS/RNS) in neurons due to NO synthase uncoupling, which leads to neurotoxicity. Progression of apoptotic or necrotic neuronal damage activates reactive astrocytes and attracts microglia or lymphocytes to migrate to place of inflammation. Those inflammatory cells start to produce large amounts of inflammatory proteins, including pathological, inducible form of NOS (iNOS), which generates nitrosative stress that further contributes to brain tissue damage, forming vicious circle of detrimental processes in the late stage of ischemia. S-nitrosylation, hypoxia-inducible factor 1 (HIF-1) and HIF-1-dependent genes activated in reactive astrocytes play essential roles in this process. The review summarizes the roles of NO-dependent pathways in the early and late aftermath of stroke and treatments based on the stimulation or inhibition of particular NO synthases and the stabilization of HIF-1 activity
Nitrofurazone Removal from Water Enhanced by Coupling Photocatalysis and Biodegradation
- Wojciech Smułek
- Zuzanna Bielan
- Amanda Pacholak
- Agata Zdarta
- Agnieszka Zgoła-Grześkowiak
- Anna Zielińska-Jurek
- Ewa Kaczorek
2021 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(1) Background: Environmental contamination with antibiotics is particularly serious because the usual methods used in wastewater treatment plants turn out to be insufficient or ineffective. An interesting idea is to support natural biodegradation processes with physicochemical methods as well as with bioaugmentation with efficient microbial degraders. Hence, the aim of our study is evaluation of the effectiveness of different methods of nitrofurazone (NFZ) degradation: photolysis and photodegradation in the presence of two photocatalysts, the commercial TiO2-P25 and a self-obtained Fe3O4@SiO2/TiO2 magnetic photocatalyst. (2) Methods: The chemical nature of the photocatalysis products was investigated using a spectrometric method, and then, they were subjected to biodegradation using the strain Achromobacter xylosoxidans NFZ2. Additionally, the effects of the photodegradation products on bacterial cell surface properties and membranes were studied. (3) Results: Photocatalysis with TiO2-P25 allowed reduction of NFZ by over 90%, demonstrating that this method is twice as effective as photolysis alone. Moreover, the bacterial strain used proved to be effective in the removal of NFZ, as well as its intermediates. (4) Conclusions: The results indicated that photocatalysis alone or coupled with biodegradation with the strain A. xylosoxidans NFZ2 leads to efficient degradation and almost complete mineralization of NFZ.
Nitrogen-Incorporated Boron-Doped Nanocrystalline Diamond Nanowires for Microplasma Illumination
- Salila Kumar Sethy
- Mateusz Ficek
- Kamatchi J Sankaran
- Sourav Sain
- Anupam R. Tripathy
- Shivam Gupta
- Jacek Ryl
- Susanta Sinha Roy
- Nyan-Hwa Tai
- Robert Bogdanowicz
2021 Full text ACS Applied Materials & Interfaces
The origin of nitrogen-incorporated boron-doped nanocrystalline diamond (NB-NCD) nanowires as a function of substrate temperature (Ts) in H2/CH4/B2H6/N2 reactant gases is systematically addressed. Because of Ts, there is a drastic modification in the dimensional structure and microstructure and hence in the several properties of the NB-NCD films. The NB-NCD films grown at low Ts (400 °C) contain faceted diamond grains. The morphology changes to nanosized diamond grains for NB-NCD films grown at 550 °C (or 700 °C). Interestingly, the NB-NCD films grown at 850 °C possess one-dimensional nanowire-like morphological grains. These nanowire-like NB-NCD films possess the co-existence of the sp3-diamond phase and the sp2-graphitic phase, where diamond nanowires are surrounded by sp2-graphitic phases at grain boundaries. The optical emission spectroscopy studies stated that the CN, BH, and C2 species in the plasma are the main factors for the origin of nanowire-like conducting diamond grains and the materialization of graphitic phases at the grain boundaries. Moreover, conductive atomic force microscopy studies reveal that the NB-NCD films grown at 850 °C show a large number of emission sites from the grains and the grain boundaries. While boron doping improved the electrical conductivity of the NCD grains, the nitrogen incorporation eased the generation of graphitic phases at the grain boundaries that afford conducting channels for the electrons, thus achieving a high electrical conductivity for the NB-NCD films grown at 850 °C. The microplasma devices using these nanowire-like NB-NCD films as cathodes display superior plasma illumination properties with a threshold field of 3300 V/μm and plasma current density of 1.04 mA/cm2 with a supplied voltage of 520 V and a lifetime stability of 520 min. The outstanding plasma illumination characteristics of these conducting nanowire-like NB-NCD films make them appropriate as cathodes and pave the way for the utilization of these materials in various microplasma device applications.