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Diamond Structures for Tuning of the Finesse Coefficient of Photonic Devices
- Monika Kosowska
- Awadesh Mallik
- Michał Rycewicz
- Ken Haenen
- Małgorzata Szczerska
2022 Pełny tekst Materials
Finesse coefficient is one of the most important parameters describing the properties of a resonant cavity. In this research, a mathematical investigation of the application of diamond structures in a fiber-optic Fabry–Perot measurement head to assess their impact on the finesse coefficient is proposed. We present modeled transmission functions of cavities utilizing a nitrogen-doped diamond, a boron-doped diamond, nanocrystalline diamond sheet and a silver mirror. The diamond structures were deposited using a microwave plasma-assisted chemical vapor deposition system. A SEM investigation of surface morphology was conducted. The modeling took into consideration the fiber-optic Fabry–Perot setup working in a reflective mode, with an external cavity and a light source of 1550 nm. A comparison of the mathematical investigation and experimental results is presented.
Diamondized carbon nanoarchitectures as electrocatalytic material for sulfate-based oxidizing species electrogeneration
- Karla Caroline de Freitas Araújo
- Elisama Vieira dos Santos
- Mattia Pierpaoli
- Mateusz Ficek
- José Eudes L. Santos
- Carlos A. Martínez-Huitle
- Robert Bogdanowicz
2022 Pełny tekst ELECTROCHIMICA ACTA
The introduction of nanotechnology seems to be an imperative factor to intensify the synergic effects of electrocatalytic materials to produce strong oxidant species or to increase the active sites on their surfaces as well as to enhance the conversion yield in a fuel cell, high-added value products, electrolytic treatment for environmental protection or the detection limit in electroanalysis. Recently, a new type of 3D-diamond electrodes was developed with boron-doped carbon nanowalls (B:CNW), which was manufactured using the microwave plasma-assisted chemical vapor deposition (CVD) process, improving the charge transfer and enhancing the electrochemical performance. The applicability of a BDD/boron-doped carbon nanowalls (BDD/B:CNW) anodes to degrade organic pollutants has been already investigated; however, no attempts at the electrosynthesis of oxidizing species using these diamond-carbon nanostructures have been reported yet. Therefore, the electrosynthesis of sulfate-based oxidizing species was studied here to answer relevant questions from both fundamental and practical point-of-view. The results demonstrated that persulfate was efficiently produced at the BBD electrode, while that the ion-radical sulfate could be the most important oxidant at BDD/B:CNW anode when compared to other electrocatalytic materials, including BDD surfaces. Persulfate concentrations ranged from 3 to 6 µM, depending on the applied current density (2.5, 5.0, and 15 mA cm−2), at diamond electrodes. A dye-model pollutant - methyl orange (MO) was degraded below the limit of detection within 45 min using BDD/B:CNW when in-situ sulfate-based oxidizing species were electrogenerated. These kinds of 3D-diamond-carbon nanostructures are thus promising as novel electrocatalyst for various catalytic applications in the environmental and energy fields.
Diatomaceous earth as a drug-loaded carrier in a glass-ionomer cement
- Magdalena Łępicka
- Magdalena Rodziewicz
- Michał Kawalec
- Klaudia Nowicka
- Yurii Tsybrii
- Jan Krzysztof Kurzydłowski
2022 Pełny tekst Journal of the Mechanical Behavior of Biomedical Materials
The effect of a natural filler (diatomaceous earth [DE], a promising drug-delivery agent) and its content was investigated on the performance of a model glass-ionomer cement (GIC). Three sample series, differing in DE content (0, 2.5 and 5 wt%), were prepared using a commercial GIC as a matrix (3M Ketac Molar Easymix). The resultant surface microhardness and roughness, wear performance, and compressive strength of the samples were measured after the samples had been stored in deionized water at 37°C for a fixed time. Moreover, the film thickness was tested for the freshly mixed samples. The numerical data was subjected to statistical analysis, in order to test the null hypotheses of the equality of the measured properties between the reference and the DE-modified samples. According to the results, diatomaceous earth particles are uniformly distributed in the GIC matrix, and the cavities of frustules tend to be filled with the GIC. This translates into the observed performance of the DE-loaded GIC. Compared with the reference material (0 wt% DE), the surface microhardness (2.5 wt% DE, p = 0.014; 5 wt% DE, p = 0.005) and roughness (e.g. Ra; 2.5 wt% DE, p = 0.003; 5 wt% DE, p < 0.001) are increased. No effect on the wear performance (p = 0.530 and 0.256, respectively) or compressive strength (p = 0.514) was noticed in the case of DE partially substituting the glass phase. Based on the study results, it is evidenced that diatom frustules are a suitable filler for application in conventional glass-ionomer cements as the glass-substituting drug-loaded carrier. Notably, however, the surface finish method of the DE-filled materials needs development.
Dietary behaviour and physical activity policies in Europe: learnings from the Policy Evaluation Network (PEN)
- Wolfgang Ahrens
- Hermann Brenner
- Marion Flechtner-Mors
- Janas M Harrington
- Antje Hebestreit
- Carlijn B.M. Kamphuis
- Liam Kelly
- Michael Laxy
- Aleksandra Luszczynska
- Mario Mazzocchi
- Celine Murrin
- Maartje Poelman
- Ingrid Hm Steenhuis
- Gun Roos
- Jürgen Meichsner
- Frank van Lenthe
- Hajo Zeeb
- Joanna Żukowska
- Jeroen Lakerveld
- Catherine B Woods
2022 Pełny tekst EUROPEAN JOURNAL OF PUBLIC HEALTH
The European Policy Evaluation Network (PEN), initiated in autumn 2018, aimed at advancing the evidence base for public policies impacting dietary behaviour, physical activity and sedentary behaviours in Europe. This is needed because non-communicable diseases—the leading cause of global mortality—are substantially caused by physical inactivity and unhealthy dietary behaviours, which in turn are driven by upstream factors that have not yet been addressed effectively by prevention approaches. Thus, successful policy interventions are required that target entire populations and tackle the ‘causes of the causes’. To advance our knowledge on the effective implementation of policies and their impact in terms of improving health behaviours, PEN focused on five research tasks: (i) Adaptation and implementation of a Food Environment Policy Index (Food-EPI) and development of a Physical Activity Environment Policy Index (PA-EPI); (ii) Mapping of health-related indicators needed for policy evaluation and facilitating a harmonized pan-European approach for surveillance to assess the impact of policy interventions; (iii) Refining quantitative methods to evaluate the impact of public policies; (iv) Identifying key barriers and facilitators of implementation of policies; and (v) Advance understanding the equity impact of the development, implementation and evaluation of policies aimed at promoting physical activity and a healthy diet. Finally, and in order to provide concrete evidence for policymaking, existing exemplary policies, namely sugar-sweetened beverages taxation, active transport policies and school policies on nutrition and physical activity were assessed in consideration of these five tasks. At the end of the PEN project’s formal runtime, considerable advancements have been made. Here, we present an overview of the most important learnings and outputs.
Digital Gaps and Economic Inequalities in MENA Countries: An Empirical Investigation
- Ewa Lechman
2022
This research contributes to the present state of the art by examining changes in cross-country inequalities in digital technologies deployment and economic performance. Our empirical target builds on the hypothesis that rapid global diffusion of digital technologies unequivocally leads to gradual eradication of cross-country digital gaps and cross-country inequalities in terms of deployment of ICT; the technology convergence occurs. Bearing in mind the fact that digital technologies’ growing access and use boost country’s economic performance, we confront changes in cross-country inequalities in terms of economic development. We hypothesize that gradual elimination of digital gaps shall be followed by diminishing gaps in economic wealth. Our country sample covers Middle East and North Africa (MENA) countries, and the time span of analysis covers the period 1990–2020. To test changes in digital development inequalities, we use 4 core ICT indicators: mobile cellular telephony, fixed broadband and mobile broadband networks, and Internet users, while regarding economic performance, we consider gross per capita income and Human Development Index. Our major findings support the hypothesis on dropping cross-country economic inequalities, which are accompanied by fast digital gaps being eradicated.
DIGITAL HYDRAULICS CIRCUIT BASED ON PWM FUNCTION FOR CONTROLLING HYDRAULIC ACTUATOR POSITION
- Jan Zubair Ahmed
- Paweł Śliwiński
- Krzysztof Kędzia
2022
Hydraulic systems are used in many different industries, such as multi-source hydrostatic drive systems. In traditional hydraulic systems, a proportional servo valve is used to control the position of hydraulic actuators. The low energy efficiency and high cost of these control valves are two major problems with these systems. Digital hydraulics is one of the most unique ideas on how to solve these problems. Researchers like digital hydraulics because it is inexpensive, it saves energy, it is not sensitive to contamination, and it has low leakage. In this paper, a digital hydraulic circuit is suggested that uses a fast switching on/off valve instead of servo valves to control the position of a hydraulic actuator. Using a proper PWM duty cycle, the flow that passes through the fast-switching valve is controlled in this way. When the control valve is off, excess pump flow flows straight to the tank instead of going through the relief valve. Therefore, the waste of energy caused by the relief valve is greatly reduced. A robust sliding mode controller (SMC) is used to ensure position tracking even when there are uncertainties.
Digital transformation and economic growth - DESI improvement and implementation
- Magdalena Olczyk
- Marta Kuc-Czarnecka
2022 Pełny tekst Technological and Economic Development of Economy
The paper aims to improve the methodology of the Digital Economic and Society Index (DESI), the European Commission’s newest index to assess the development of the digital economy. In particular, we investigate whether methodological changes to the structure of DESI improve its ability to capture the digital transformation of EU economies. Using the sensitivity- based analysis, we check whether the selection of weights of individual elements included in the DESI is optimal or should be improved. We also verify the importance of DESI in explaining changes in GDP per capita in EU econo- mies. In the literature, we find that digital transformation has enabled the creation of new business models and maximized efficiency in traditional firms. Using DESI, we empirically test whether the gap between rich and poor countries in European Union can be closed or eliminated through rapid and intensive digital transformation. Our results show that the DESI – when modified by eliminating the pillars on internet services and digital public services – has the same explanatory power. Connectivity is the dimension with the largest impact on digital transformation in EU countries. We also find that DESI is a signifi- cant regressor to explain changes in GDP per capita in EU countries
Digitalizacja nie śpi! Czy w Bibliotece Politechniki Gdańskiej sprostamy wyzwaniom stawianym przez cyfrową humanistykę?
- Kamila Kokot-Kanikuła
- Anna Sobolewska
2022 Pełny tekst Biuletyn EBIB
Celem artykułu jest przedstawienie działań Biblioteki Politechniki Gdańskiej w zakresie digitalizacji oraz udostępniania zasobów kultury i nauki na platformie Pomorskiej Biblioteki Cyfrowej. Podejmowane zadania zostały zestawione z ogłoszonymi w 2020 r. postulatami międzynarodowej organizacji DARIAH zajmującej się dostarczaniem społecznościom naukowym metod cyfrowych do tworzenia, łączenia i dzielenia się wiedzą.
Digitalization of High Speed Craft Design and Operation Challenges and Opportunities
- Abbas Dashtimanesh,
- Mohammad Ghaemi
- Youjiang Wang
- Artur Karczewski
- Rasul Niazmand Bilandi
- Spyros Hirdaris
2022 Pełny tekst Procedia Computer Science
In recent years, global demands for safe and sustainable ships led to dramatic changes in the maritime industry. Digitalization is expected to play an important part in the future. This is supported by analysis of the autonomous ships market which shows that digitalization of large ship types such as tankers and container ships is well on track. Although to date designs of autonomous High-Speed Craft (HSC) have been developed, there are only a few studies on the impact of digitalization on design and operations. This is because of the challenging operational profile of these assets across a spread of waterborne activities namely fishing, leisure, patrolling, and rescuing. This paper reviews the literature of relevance on the potential of digitalization of the HSC sector in the Baltic. An overview of the systems that could be partly digitalized and how technology developments may influence operations are also outlined.
Digitalization Process and Its Impact on Economic Growth A Panel Data Study for Developing Countries
- Ewa Lechman
- Helena Anacka
2022
This book analyses the impact of Information and Communication Technologies (ICTs) on economic development. It contains theoretical and empirical studies, including panel studies on various issues facing developing countries, such as education, corruption, economic growth, government expenditure, financial inclusion, foreign direct investment, infrastructure, economic and social welfare, and inequality. Each chapter offers a well-conceived analysis of the most recent trends in both theory and empirics and addresses numerous policy implications related to the different aspects dealt with in the volume.
Direct Constraint Control for EM-Based Miniaturization of Microwave Passives
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
2022 Pełny tekst Scientific Reports
Handling constraints imposed on physical dimensions of microwave circuits has become an important design consideration over the recent years. It is primarily fostered by the needs of emerging application areas such as 5G mobile communications, internet of things, or wearable/implantable devices. The size of conventional passive components is determined by the guided wavelength, and its reduction requires topological modifications, e.g., transmission line folding, or utilization of compact cells capitalizing on the slow-wave phenomenon. The resulting miniaturized structures are geometrically complex and typically exhibit strong cross coupling effects, which cannot be adequately accounted for by analytical or equivalent network models. Consequently, electromagnetic (EM)-driven parameter tuning is necessary, which is computationally expensive. When the primary objective is size reduction, the optimization task becomes far more challenging due to the presence of constraints related to electrical performance figures (bandwidth, power split ratio, etc.), which are all costly to evaluate. A popular solution approach is to utilize penalty functions. Therein, possible violations of constraints degrade the primary objective, thereby enforcing their satisfaction. Yet, the appropriate setup of penalty coefficients is a non-trivial problem by itself, and is often associated to extra computational expenses. In this work, we propose an explicit approach to constraint handling, which is combined with the trust-region gradient-search procedure. In our technique, the decision about the adjustment of the search radius is determined based on the reliability of rendering the feasible region boundary by linear approximation models of the constraints. Comprehensive numerical experiments conducted using three miniaturized coupler structures demonstrate superiority of the presented method over the penalty function paradigm. Apart from the efficacy, its appealing features include algorithmic simplicity, and no need for tailoring the procedure for a particular circuit to be optimized.
Direct-contact condensation from vapour- gas mixture in a spray ejector condenser for negative CO2 power plant
- Dariusz Mikielewicz
- Milad Amiri
- Jaroslaw Mikielewicz
2022 Pełny tekst
Direct-contact condensation of vapour containing the inert gas on a spray of subcooled liquid exists in a number of technical applications. For example, it may be found in the nuclear industry (e.g. pressurized jet under normal operating conditions, in safety analyses) or in the chemical industry (e.g. mixing-type heat exchanger, degasser, sea water desalting). The problem is also essential to modelling and analysis of some fundamental phenomena of two phase flow, such as condensation in power engineering condenser of steam power plant as well as a new concept of negative CO2 power plant, where separation of carbon dioxide from the mixture of steam and inert gas takes place in the spray ejector condenser (SEC) followed by the centrifugal separation in the cyclone. The phenomenon of direct-condensation heat transfer is primarily characterized by the appropriate transport of heat and mass through a moving vapour-liquid interface. Furthermore, using a spray ejector condenser (SEC) with separators can be considered as an alternative method to increase the efficiency of separation process. The present survey attempts to investigate the effect of different initial velocity of mixture and droplet on their temperature as well as the effect of diameter of throat on temperature of droplet and mixture. For the ejector design, the study focuses on the ejector nozzle, pre-mixing chamber, the mixing section and the diffuser. Flow properties and ejector geometry are considered using the thermodynamic equations, conservation equations and other assumptions established based on literature. Comparisons with experimental data show a good consistency with experimental results. Results show that increasing the value of initial velocity of mixture of steam (Um0) not only results in increasing the temperature of droplet, but also leads to rise the temperature of mixture of steam at the length of throat. Moreover, the lowest value for temperature of droplet and mixture of steam is when the drop is moving in stagnant environment (() = 0).
Direction of Arrival Estimation Based on Received Signal Strength Using Two-Row Electronically Steerable Parasitic Array Radiator Antenna
- Mateusz Rzymowski
- Krzysztof Nyka
- Łukasz Kulas
2022 Pełny tekst SENSORS
In this paper, we present a novel approach to direction-of-arrival (DoA) estimation using two-row electronically steerable parasitic array radiator (ESPAR) antenna which has 12 passive elements and allows for elevation and azimuth beam switching using a simple microcontroller, relying solely on received signal strength (RSS) values measured at the antenna output port. To this end, we thoroughly investigate all 18 available 3D antenna radiation patterns of the antenna measured in an anechoic chamber with respect to radiation coverage in the horizontal and vertical direction and propose a generalization of the power-pattern cross-correlation (PPCC) algorithm involving a high number of multiple calibration planes (MCP) as well as specific combinations of radiation pattern sets. Additionally, a new way of RSS-based DoA estimation accuracy assessment, which involves thorough testing conducted along the elevation direction when RF signals impinging on the antenna arrive from arbitrary θ angles, has been reported in this paper to verify the overall algorithm’s performance. The results obtained for different signal-to-noise ratio (SNR) levels indicate that two-row ESPAR antenna can produce, even for low SNR values, accurate DoA estimation in the horizontal plane without prior knowledge about the elevation direction of the unknown RF signals by using appropriate combinations of only 12 3D antenna radiation patterns.
Directions of Energy Transition of Uzbekistan
- Krystyna Gomółka
- Piotr Kasprzak
2022
The aim of the paper is to present the changes in the Uzbekistan energy market over the past few years. Uzbekistan is self-sufficient in terms of energy resources, the exploitation of which will last for many years. In 2019, the government adopted the "Concept Note ensuring electricity supply in Uzbekistan in 2020-2030" strategy, which announced the modernization of gas and coal power plants and the construction of new energy facilities, mainly photovoltaic. The projected increase in energy until 2030 assumes a 25% share in the production of renewable energy sources. A novelty in the work is the analysis of energy projects implemented until September 2021 in Uzbekistan. Its results show that the planned 25% share of renewable energy sources in the overall energy balance of Uzbekistan may not be achieved because financial resources from international sources have been allocated to the modernization of the existing gas and coal-fired power plants.
Discovering interactions between applications with log analysis
- Krzysztof Goczyła
- Łukasz Korzeniowski
2022 Pełny tekst Annals of Computer Science and Information Systems
Application logs record the behavior of a system during its runtime and their analysis can provide useful information. In this article, we propose a method of automated log analysis to discover interactions taking place between applications in an enterprise. We believe that such an automated approach can greatly support enterprise architects in building an up-to-date view of a governed system in a modern, fast-paced development environment. Our contribution is the following: we propose a new method for log template generation called SLT (Simple Log Template), we propose a method of extracting knowledge about application interactions from logs, and we validate the proposed methods on a real system running at Nordea Bank. Additionally, we collect statistical information about application logs from the real-life system, based on which we formulate some observations that support our method.
Discussion of “Stress-Displacement Response of Sand–Geosynthetic Interfaces under Different Volume Change Boundary Conditions” by Aliyeh Afzali-Nejad, Ali Lashkari, and Alejandro Martinez
- Lech Bałachowski
- Jakub Konkol
2022 Pełny tekst JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
The influence of normal stiffness of interface on the interpretation of shear box tests
Dispersive Delay Structures With Asymmetric Arbitrary Group-Delay Response Using Coupled-Resonator Networks With Frequency-Variant Couplings
- Maciej Jasiński
- Martyna Mul
- Adam Lamęcki
- Roberto Gomez-Garcia
- Michał Mrozowski
2022 Pełny tekst IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
This article reports the design of coupled-resonatorbased microwave dispersive delay structures (DDSs) with arbitrary asymmetric-type group delay response. The design process exploits a coupling matrix representation of the DDS circuit as a network of resonators with frequency-variant couplings (FVCs). The group delay response is shaped using complex transmission zeros (TZs) created by dispersive cross-couplings. We also present an optimization-based synthesis procedure for characteristic polynomials with a prescribed group delay profile. Thus, when compared with prior-art DDS approaches, the proposed DDS solutions allow a general group delay profile to be patterned while incorporating optimization-based coupling matrix design techniques for their synthesis. The design method is validated by full-wave simulations and measurements of three built proof-ofconcept prototypes of DDS devices with different shapes of group delay response in waveguide and microstrip technologies
Displacement Sensors Based on the Phase of the Reflection Coefficient of a Split Ring Resonator Loaded Transmission Line
- Zahra Shaterian
- Michał Mrozowski
2022 IEEE SENSORS JOURNAL
— In this paper, novel displacement sensors using a microstrip loaded with a pair of split ring resonators (SRRs) are proposed. It is shown that the phase of the reflection coefficient from the loading SRRs can be used for displacement sensing. The paper also proposes a differential version of the sensor that benefits from a higher sensitivity and reference zero, which is useful for alignment purposes. It is further shown that the concept of interferometry can be used to convert the output variable of the sensor from changes in the phase to variation in the amplitude of the reflected wave, which can be easily measured. To this end, the proposed single-ended or differential sensors are used along with a branch-line coupler. The proposed sensing mechanism is validated through EM simulation of the structures. The concept is further validated through the fabrication and measurement of a prototype
Divulging the anti-acetylcholinesterase activity of Colletotrichum lentis strain KU1 extract as sustainable AChE active site inhibitors
- Anoop Kallingal
- Aravind Ayyolath
- Varun Thachan Kundil
- Akshay M S
- Tomy Muringayil
- Józef Haponiuk
- Sabu Thomas
- Anu Augustine
2022 Pełny tekst ARCHIVES OF MICROBIOLOGY
Alzheimer’s disease (AD), also called senile dementia is a neurodegenerative disease seen commonly in the elderly and is characterised by the formation of β-amyloid plaques and neurofbrillary tangles (NFT). Though a complete understanding of the disease is lacking, recent studies showed the role of the enzyme acetylcholinesterase (AChE) in pathogenesis. Finding new lead compounds from natural sources has always been a quest for researchers. Endophytic fungi are a set of microbes that reside within plants without causing any harm. This study focuses on screening endophytes for the production of active acetylcholinesterase inhibitors. Five endophytic fungi were isolated from Catharanthus roseus and screened for AChE inhibitory activity. Three isolates were found to inhibit AChE inhibitory activity and were distinguished based on molecular and microscopic methods. The mycelial extract was taken for the bioassay-guided column chromatography and TLC was performed on the active fraction. The GC–MS and NMR analysis identifed the active compounds in the extract as 9-hexadecen-1-ol and erucamide. Molecular docking studies revealed that the compounds are thermodynamically feasible and have signifcant glide scores. Computational studies revealed that the hydroxyl group of 9-hexadecen-1-ol forms a hydrogen bond with Ser 293 in the active site of AChE, whereas the active site interactions were predominantly hydrophobic in the case of erucamide and are refected in AChE inhibition assays.
DMSO and TMAO—Differences in Interactions in Aqueous Solutions of the K-Peptide
- Julia Godlewska
- Bartosz Cieśla
- Jarosław Wawer
- Piotr Bruździak
2022 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Interactions between a solvent and their co-solute molecules in solutions of peptides are crucial for their stability and structure. The K-peptide is a synthetic fragment of a larger hen egg white lysozyme protein that is believed to be able to aggregate into amyloid structures. In this study, a complex experimental and theoretical approach is applied to study systems comprising the peptide, water, and two co-solutes: trimethylamide N-oxide (TMAO) or dimethyl sulfoxide (DMSO). Information about their interactions in solutions and on the stability of the K-peptide was obtained by FTIR spectroscopy and differential scanning microcalorimetry. The IR spectra of various osmolyte–water–model-peptide complexes were simulated with the DFT method (B3LYP/6-311++G(d,p)). The FTIR results indicate that both solutes are neutral for the K-peptide in solution. Both co-solutes affect the peptide to different degrees, as seen in the shape of its amide I band, and have different influences on its thermal stability. DFT calculations helped simplify the experimental data for easier interpretation.