2023 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2023

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Neurodiversity and remote work in times of crisis: lessons for HR
- Joanna Szulc
- Frances-Louise McGregor
- Emine Cakir
2023 Full text Personnel Review
Purpose The rich qualitative study builds on 11 semi-structured interviews with nine neurodivergent employees and two business professionals supportive of neurodiversity to understand the lived experiences of dealing with crisis in a remote working environment. Design/methodology/approach The purpose of the reported research is to understand how neurominorities experience remote working in the times of crisis and what the implications of this are for human resource (HR) professionals. Findings Moving to remote work resulted in a lack of routine, distractions and working long hours, which can all be difficult for line managers to monitor. Further problems with communication in a virtual environment and lack of understanding by others were found to be particularly burdensome to neurodivergent individuals. On the positive note, remote working in the times of crisis allowed for avoiding sensory overwhelm and was seen as an important step in creating a healthy work–life balance (WLB). Practical implications The findings of this study point HR practitioners' attention towards building a more neurodiversity friendly post-pandemic workplace and prompt employers to offer working arrangements, which better suit employees' domestic and personal circumstances. Originality/value This study addresses the lack of research on the impact of the Covid-19 crisis on neurominorities. In doing so, it answers recent calls to move away from universal HR as a route to positive employee outcomes and facilitates a more accurate reflection of organizational reality for disadvantaged members of society.
New Complementary Resonator for Permittivity- and Thickness-Based Dielectric Characterization
- Tanveer Haq Ul
- Sławomir Kozieł
2023 Full text SENSORS
The design of high-performance complementary meta-resonators for microwave sensors featur-ing high sensitivity and consistent evaluation of dielectric materials is challenging. This paper presents the design and implementation of a novel complementary resonator with high sensi-tivity for dielectric substrate characterization based on permittivity and thickness. A comple-mentary crossed arrow resonator (CCAR) is proposed and integrated with a fifty-ohm mi-crostrip transmission line. The CCAR's distinct geometry, which consists of crossed ar-row-shaped components, allows for implementing a resonator with exceptional sensitivity to changes in permittivity and thickness of the material under test (MUT). The CCAR's geometrical parameters are optimized to resonate at 15 GHz. The CCAR sensor's working principle is ex-plained using a lumped-element equivalent circuit. The optimized CCAR sensor is fabricated using LPKF protolaser on a 0.762-mm-thick dielectric substrate AD250C. The MUTs with dielec-tric permittivity ranging from 2.5 to 10.2 and thickness ranging from 0.5 mm to 1.9 mm are used to investigate the properties and calibrate the proposed CCAR sensor. A two-dimensional cali-bration surface is developed using an inverse regression modelling approach to ensure precise and reliable measurements. The proposed CCAR sensor is distinguished by its high sensitivity of 5.74 percent, low fabrication cost, and enhanced performance compared to state-of-the-art de-signs, making it a versatile instrument for dielectric characterization.
New Design of Axial Piston Pump with Displaced Swash Plate Axis of Rotation for Hydro-Mechanical Transmissions
- Paweł Załuski
- Piotr Patrosz
- Marcin Bąk
2023
This paper presents a prototype design of an axial piston pump with displaced swash plate axis of rotation in two directions of discharge with electronic control intended for installation on a hydraulic-mechanical gearbox dedicated to working machines. The effect of displacement of the swash plate rotation axis on dead space volume and volumetric efficiency is presented. The construction and principle of operation of the capacity change mechanism and the delivery direction change mechanism are described. The design and hydraulic diagram of the pump are presented.
New empirical correlations for the viscosity of selected organic phase change materials
- Janusz Cieśliński
- Maciej Fabrykiewicz
- Tomasz Wiśniewski
- Michał Kubiś
- Slawomir Smolen
- Albrecht Eicke
- Krzysztof Dutkowski
- Małgorzata Głuszek-Czarnecka
2023 Full text Archives of Thermodynamics
Although there are many methods and instruments for measuring viscosity, it is still difficult to determine a reliable value of the dynamic viscosity of complex chemicals such as paraffins and fatty acids. This is due to the complex and heterogeneous structure of these compounds in the case of commercial products. On the other hand, the measuring instrument should be selected very carefully, including its measuring principle and measuring range. This paper presents results of viscosity measurements of three organic PCMs (phase change materials) obtained in four different research institutions. Commercial products: paraffin, myristic acid (97%) and mixture of palmitic acid (55%) and stearic acid (45%) were selected as PCMs. Four different viscometers, namely Fungilab V-Pad, Rheotest LK 2.2, Rheometer Anton Paar MCR 102, and Brookfield DV-II + Pro have been used to determine temperature dependent dynamic viscosity of the tested PCMs. Using a large database of present measurement results, correlations were developed to calculate the dynamic viscosity of fatty acids and paraffins, which predict the experimental data within a band of ±20%.
New, fast and cheap prediction tests for BRCA1 gene mutations identification in clinical samples.
- Aleksandra Gajda-Walczak
- Agnieszka Potęga
- Agata Kowalczyk
- Sławomir Sęk
- Sebastian Zięba
- Artur Kowalik
- Andrzej Kudelski
- Anna M. Nowicka
2023 Full text Scientific Reports
Despite significant progress in cancer therapy, cancer is still the second cause of mortality in the world. The necessity to make quick therapeutic decisions forces the development of procedures allowing to obtain a reliable result in a quick and unambiguous manner. Currently, detecting predictive mutations, including BRCA1, is the basis for effectively treating advanced breast cancer. Here, we present new insight on gene mutation detection. We propose a cheap BRCA1 mutation detection tests based on the surface plasmon resonance (SPR) or quartz crystal microbalance with energy dissipation (QCM-D) response changes recorded during a hybridization process of an oligonucleotide molecular probe with DNA fragments, with and without the BRCA1 mutation. The changes in the morphology of the formed DNA layer caused by the presence of the mutation were confirmed by atomic force microscopy. The unique property of the developed SPR and QCM tests is really short time of analysis: ca. 6 min for SPR and ca. 25 min for QCM. The proposed tests have been verified on 22 different DNA extracted from blood leukocytes collected from cancer patients: 17 samples from patients with various BRCA1 gene mutation variants including deletion, insertion and missense single-nucleotide and 5 samples from patients without any BRCA1 mutation. Our test is a response to the need of medical diagnostics for a quick, unambiguous test to identify mutations of the BRCA1 gene, including missense singlenucleotide (SNPs).
New hybrid quadrature schemes for weakly singular kernels applied to isogeometric boundary elements for 3D Stokes flow
- Maximilian Harmel
- Roger Sauer
2023 ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
This work proposes four novel hybrid quadrature schemes for the efficient and accurate evaluation of weakly singular boundary integrals (1/r kernel) on arbitrary smooth surfaces. Such integrals appear in boundary element analysis for several partial differential equations including the Stokes equation for viscous flow and the Helmholtz equation for acoustics. The proposed quadrature schemes apply a Duffy transform-based quadrature rule (Duffy, 1982) to surface elements containing the singularity and classical Gaussian quadrature to the remaining elements. Two of the four schemes additionally consider a special treatment for elements near to the singularity, where refined Gaussian quadrature and a new moment-fitting quadrature rule are used. The hybrid quadrature schemes are systematically studied on flat B-spline patches and on NURBS spheres considering two different sphere discretizations: An exact single-patch sphere with degenerate control points at the poles and an approximate discretization that consist of six patches with regular elements. The efficiency of the quadrature schemes is further demonstrated in boundary element analysis for Stokes flow, where steady problems with rotating and translating curved objects are investigated in convergence studies for both, mesh and quadrature refinement. Much higher convergence rates are observed for the proposed new schemes in comparison to classical schemes.
New LED photoreactor with modulated UV–vis light source for efficient degradation of toluene over WO3/TiO2 photocatalyst
- Joanna Mioduska
- Marcin Łapiński
- Jakub Karczewski
- Jan Hupka
- Anna Zielińska-Jurek
2023 CHEMICAL ENGINEERING RESEARCH & DESIGN
The efficiencies of prepared WO3/TiO2 photocatalysts with varying amounts of WO3 were evaluated for gas-phase photocatalytic degradation of toluene. The obtained results revealed that the best photocatalytic properties were characteristic for samples calcined at 500ºC, which can be associated with high crystalline phase content (> 97%) and favourable BET surface area. The photocatalytic degradation tests were performed in two photoreactors equipped with different LED arrays as light sources – a flat circular reactor and a scaled-up batch photoreactor. In the first photoreactor, experiments performed under UV light (375 nm) revealed a negligible effect of WO3 content in the range of 0.1–3% mol on the photocatalytic activity. 1–hour irradiation contributed to around 99% elimination of toluene. Higher WO3 content (5% mol WO3) affected a 10% reduction in toluene removal. Furthermore, toluene degradation was performed in a scaled-up LED batch photoreactor equipped with modulated irradiation source consisting of a set of LEDs with wavelengths of 365 nm, 400 nm, and 450 nm appropriately selected for the photocatalytic material optical properties. The processes performed in a scaled-up photoreactor with a volume of 1 dm3 in the presence of a sample containing 2 mol% of WO3 showed above 80% effectiveness in toluene degradation after only 30 min of irradiation.
New light on the photocatalytic performance of NH4V4O10 and its composite with rGO
- Małgorzata Nadolska-Dawidowska
- Mariusz Szkoda
- Konrad Trzciński
- Jacek Ryl
- Aneta Lewkowicz
- Kamila Sadowska
- Julita Smalc-Koziorowska
- Marta Prześniak-Welenc
2023 Full text Scientific Reports
Solar-driven photocatalysis has shown great potential as a sustainable wastewater treatment technology that utilizes clean solar energy for pollutant degradation. Consequently, much attention is being paid to the development of new, efficient and low-cost photocatalyst materials. In this study, we report the photocatalytic activity of NH4V4O10 (NVO) and its composite with rGO (NVO/rGO). Samples were synthesized via a facile one-pot hydrothermal method and successfully characterized using XRD, FTIR, Raman, XPS, XAS, TG-MS, SEM, TEM, N2 adsorption, PL and UV‒vis DRS. The results indicate that the obtained NVO and NVO/rGO photocatalysts exhibited efficient absorption in the visible wavelength region, a high content of V4+ surface species and a well-developed surface area. Such features resulted in excellent performance in methylene blue photodegradation under simulated solar light illumination. In addition, the composite of NH4V4O10 with rGO accelerates the photooxidation of the dye and is beneficial for photocatalyst reusability. Moreover, it was shown that the NVO/rGO composite can be successfully used not only for the photooxidation of organic pollution but also for the photoreduction of inorganic pollutants such as Cr(VI). Finally, an active species trapping experiment was conducted, and the photodegradation mechanism was discussed.
NEW PRODUCT DEVELOPMENT FROM THE PERSPECTIVE OF CREATING A COMPETITIVE ADVANTAGE
- Dariusz Dąbrowski
2023 Full text Marketing Instytucji Naukowych i Badawczych
It is acknowledged that achieving product-based competitive advantage is a key task for a company. However, there is still a research gap in determining those specific actions in the process of developing new products that arise from companies' efforts to achieve product-based competitive advantage. Therefore, the aim of this study is to determine the specific actions in the new product development (NPD) process that result from companies' intention to introduce a new product to the market, enabling the achievement of a competitive advantage. The primary research method used in this study is deductive reasoning, supplemented by a literature review. The result of the study is the proposal of three types of actions: a) evaluating an opportunity in terms of its potential to generate a competitive advantage; b) creating a new product with high economic value; and c) assessing both the planned new product and the new product introduced to the market in terms of achieving a competitive advantage. The latter two types of actions can be undertaken at various stages of the NPD process and can pertain to the product concept itself and to specific product forms (e.g., prototypes, pilot products). These proposed actions are significant because attaining a product-based competitive advantage contributes to the achievement of other objectives related to new products (e.g., revenue generation). Therefore, it is recommended that companies incorporate these actions into their NPD process. This study contributes to the field of management by proposing few specific actions in each phase of the NPD process, which arise from a company's intention to achieve a product-based competitive advantage, addressing a previous gap in the literature.
New Transparent Flame-Retardant (FR) Coatings Based on Epoxy-Aluminum Hypophosphite Nanocomposites
- Fouad Laoutid
- Maryam Jouyandeh
- Oltea Murariu
- Henri Vahabi
- Mohammad Saeb
- Loic Brison
- Marius Murariu
- Philippe Dubois
2023 Full text Coatings
The present study investigated the flame-retardant (FR) effect of transparent epoxy coating containing aluminum hypophosphite (AHP) nanoparticles (NPs) on polylactic acid (PLA) sheets used as a typical model of combustible polymeric material. First, AHP NPs (≤60 nm) were prepared by a specific two-stage wet milling process and deeply analyzed (morphology, thermal/mechanisms of degradation under nitrogen and air). The thermal properties of epoxy–AHP nanocomposites were compared with the pristine epoxy resin. The addition of AHP NPs into epoxy resin accelerated thermal degradation of the coating, thereby increasing the amount of char residue. The application of blank epoxy coating on the surface of PLA plate slightly made PLA more ignitable, without any reduction in the peak of heat release rate (pHRR). The decrease of time to ignition (TTI) was more important in the presence of AHP NPs due to their reactivity toward epoxy resin. Epoxy coating containing 15 wt.% AHP NPs showed the most significant reduction in pHRR as the result of the formation of a homogenous char layer. Further increase of AHP NPs content up to 20 wt.% did not end in any further enhancement, as a consequence of structural cracks observed in the coating that prevent the formation of an effective char. The coated samples remained transparent, promisingly paving the way to appropriate decorative flame-retardant coatings.
Nexus between stock markets, economic strength, R&D and environmental deterioration: new evidence from EU-27 using PNARDL approach
- Muhammad Mushafiq
- Błażej Prusak
2023 Full text ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
This research investigates the impact of stock market indices, economic strength, and research and development expenditures on environmental deterioration in the EU-27 countries for the period 2000–2020. This study utilized linear and non-linear panel ARDL to estimate the short- and long-run effect. According to the results, the stock market indices have negative effect on environmental deterioration in the symmetric form. However, the asymmetric evidence shows that in the long run the positive shocks of stock market indices contribute positively to the environmental deterioration and negative shocks decrease the environmental deterioration. This effect is reversed in the short run. Linear effect of economic strength on environmental deterioration is positive. For non-linear effect, the long-run shocks show no difference. However, the negative shock of economic strength in the short run causes an increase in the environmental deterioration. Symmetric evidence for research and development increases environmental deterioration. However, asymmetric results show weak evidence. The study has policy implications in context of achieving sustainable development goals.
Nick Srnicek. Kapitalizm platform.Przekład i opracowanie naukowe: Janusz Grygieńć i Andrzej Karalus
- Janusz Grygieńć
- Andrzej Karalus
2023
Autor książki dowodzi, że aby zrozumieć współczesną gospodarką należy analizować największe spółki technologiczne, traktując je jako aktorów ekonomiczni w ramach kapitalistycznego systemu produkcji. Punktem wyjścia jest diagnoza, iż w wyniku długotrwałego spadku rentowności produkcji przemysłowej kapitalizm zaczął wykorzystywać dane do tego, żeby utrzymać wzrost gospodarczy oraz witalność, których nie mógł zapewnić sektor produkcyjny. W XXI wieku, w związku z ewolucją technologii cyfrowych, dane stają się coraz bardziej istotne dla firm i ich relacji z pracownikami, klientami oraz z innymi podmiotami gospodarki kapitalistycznej. Platforma wyłoniła się jako nowy model biznesowy, zdolny do gromadzenia i kontrolowania ogromnych ilości danych, a wraz z tą zmianą można było zaobserwować powstanie dużych firm monopolistycznych. Dziś kapitalizm średnio i wysokodochodowych gospodarek jest coraz bardziej zdominowany przez tego typu firmy, a zarysowana w książce dynamika sugeruje, że trend ten będzie się tylko utrzymywał.
Nickel phase deposition on V2CTx/V2AlC as catalyst precursors for a dry methane reforming: The effect of the deposition method on the morphology and catalytic activity
- Izabela Wysocka
- Jakub Karczewski
- Anna Gołąbiewska
- Marcin Łapiński
- Bartłomiej Cieślik
- Michał Maciejewski
- Barbara Kościelska
- Andrzej Rogala
2023 INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
Dry reforming of methane (DRM) is a promising alternative technology for the production of syngas with simultaneous utilization of two main greenhouse gases (CH4, CO2). However, DRM technology is still an industrially immature process due to the lack of stable and active catalyst. Therefore, the search for new catalytic materials is of great research interest. Recently, MAX and MXenes materials are increasingly being tested as potential materials for catalytic processes including dry reforming of hydrocarbons. However, transition metal carbides may be deactivated under DRM conditions due to phase transition caused by an oxidation process. The combining of the MAX/MXene materials with nickel phase may be beneficial for to improve catalytic activity and stability. In this view, we report preparation and characterization of nickel-modified V2CTx/V2AlC materials. The Ni–V2CTx/V2AlC catalysts were prepared using HF-etching followed by impregnation/precipitation method. The effect of preparation route on morphology and catalytic activity was investigated. The properties of fresh and spent catalysts were evaluated using XRD, XPS, MP-AES, SEM, BET surface area, H2-TPR, CO2-TPD, TG/DTG and TEM techniques. Catalytic activity was investigated in the DRM process at 800 °C and 1 bar. It was found that the V2CTx/V2AlC- based materials undergo phase transition to vanadium oxide V2O3, vanadium carbide V8C7 and aluminium oxide. The presence of nickel was crucial for the catalyst activity of V2CTx/V2AlC- based catalysis. The catalytic activity was different and related to the preparation procedure resulting in dissimilar nickel-phase morphology and intercalation of sodium ions. It was found that the distribution of nickel phase and presence of alkali ions determined catalysts’ activity and stability. The highest activity and stability in DRM process was observed for Ni–V2CTx/V2AlC_IMP catalysts obtained using only impregnation method without precipitation agents. For the catalysts nickel phase was distributed uniformly forming needle-like structures. The CO2 and CH4 conversions during 20 h-test were in the range of 90–93% and 90-80%, respectively. The molar ration of H2 to CO in outlet stream fluctuated from 1.05 in the first hour of the process to 0.95 after 20 h of the DRM. The activity and stability of Ni–V2CTx/V2AlC_IMP catalyst was higher compared to unmodified V2CTx/V2AlC, unetched V2AlC and Ni–SiO2.
Nickel-based catalysts for electrolytic decomposition of ammonia towards hydrogen production
- Justyna Łuczak
- Marek Lieder
2023 Full text ADVANCES IN COLLOID AND INTERFACE SCIENCE
Nickel is an attractive metal for electrochemical applications because it is abundant, cheap, chemically resilient, and catalytically active towards many reactions. Nickel-based materials (metallic nickel, its alloys, oxides, hydroxides, and composites) have been also considered as promising electrocatalysts for ammonia oxidation. The electrolysis of ammonia aqueous solution results in evolution of gaseous hydrogen and nitrogen. Up to date studies showed that metallic Ni and Ni (hydro)oxides are not catalytically active unless they are electrochemically converted to NiOOH at ~1.3 V vs. RHE. Then, dehydrogenation of NH3 begins with electron-coupled proton transfer to NiOOH resulting in a would-be reversible reduction of the latter to Ni(OH)2. Unlike the water electrolysis process, in which solely oxygen is obtained at the anode, during ammonia electrooxidation apart from release of N2, many undesired oxygenated nitrogen moieties may also turn up. These products appear after at least partial dehydrogenation of ammonia. Studies on NiOOH activity have been conducted for systems containing various modifiers, e.g., Cu, Co, S, P, however, their particular role in catalytic activity has not yet been elucidated. Nowadays research is being conducted in the direction of increasing the activity, selectivity, and stability of NiOOH. In this review, the electroactivity of Ni is analyzed and discussed in accordance with its oxidation states along with the ammonia oxidation mechanism. The main research problems to be solved and challenges for the future industrial use of ammonia are presented
Nitrogen transformation during fermentation in agricultural biogas plants
- Anna Wilińska-Lisowska
- Otton K. Roubinek
- Andrzej G. Chmielewski
- Krzysztof Czerwionka
2023 Full text Biomass Conversion and Biorefinery
The aim of the present study was to determine changes in the organic nitrogen fraction in the liquid fraction of the digestate during laboratory tests of mono- and co-digestion. Three agricultural wastes were tested: distillery residue, cattle slurry and corn silage. In the mono-fermentation tests, the initial total nitrogen concentration depended on the feedstock used. As a result of the hydrolysis and ammonification of the organic matter contained in the feedstocks, there was an increase in ammonium nitrogen concentration after 28 days of fermentation. Analysis of organic nitrogen fractions showed that different organic nitrogen fractions predominated in each of the feedstocks. Four co-digestion tests were performed with 20% and 80% inoculum content and the combination of feedstocks used in the mono-fermentation. Proper evaluation of the transformation of nitrogen forms for the tests with 20 and 80% inoculum participation required the calculation of concentrations from the mass balance, taking into account the effect of changes taking place in the inoculum itself (control test). For these tests, the initial concentrations of nitrogen forms are similar to those found in the mono-fermentation tests. A greater increase in ammonium nitrogen concentrations was found for the test with 80% inoculum than in the test with 20% (for the same feedstock). An increase in the removal efficiency of the dissolved organic nitrogen fraction (DON), and an increase for the colloidal (CON) and particulate organic nitrogen (PON) fractions after 28 days of co-digestion were observed. The trend of change was similar for 20% and 80% inoculum.
Ni-WC/Al2O3 and Ni-WC/MgWO4/MgAl2O4 catalysts for resource recovery via pyrolysis combined with the dry reforming of plastics (PCDR)
- Izabela Wysocka
- Jakub Karczewski
- Michał Maciejewski
- Barbara Kościelska
- Adam Kubiak
- Andrzej Rogala
- Jacek Gębicki
2023 Full text Journal of Environmental Chemical Engineering
Plastic waste (PW) is currently one of an environmental threat. Despite the increasing share of recycled plastics, their disposal remains high. Therefore, there is a high demand for new PW management systems. Among them, pyrolysis combined with dry reforming (PCDR) is an advantageous solution because it allows for resource recovery in the form of gas and liquid fuels, with simultaneous utilization of CO2. To date, catalysts based on Ni, Co, and noble metals supported on metal oxides have been examined. However, these catalysts suffer from quick deactivation due to coking and sintering. Therefore, testing other materials for PCDR is of particular importance. In this regard, Ni-WC/Al2O3 and Ni-WC/MgWO4/MgAl2O4 were investigated as potential PCDR catalysts. The catalysts were characterized by BET, BJH, XRD, CO2-TPD, H2-TPR, SEM, TEM, TG and DTG. The catalytic activity was evaluated in a two-step PCDR process using low-density polyethylene (LDPE), polystyrene (PS), polyethylene terephthalate (PET), and simulated waste plastic (SWP). The structure of the polymer strongly determines the yields of gas, liquid, and solid products. The highest yield of synthetic gas generation was observed for Ni-WC/MgWO4/MgAl2O4 and was 48.20 ± 2.41 mmol/gp. Different origins of the structural changes including oxidation or coking were observed for different plastics. PCDR of PET led mainly to oxidation, LDPE to the coking deposition. Catalysts after the process with PS were characterized by preservation of crystalline structure. The results indicate a high potential of carbide catalysts in the recovery of gaseous and liquid raw materials.
Noise effect on parameters of quiet sonar with code modulation
- Roman Salamon
- Jacek Marszal
- Andrzej Jedel
2023 Full text Vibrations in Physical Systems
Earlier publications of the paper authors have shown that the use of code keying mixed with the CW FM sound signal allows the significant reduction in the distance measurement error, compared to classic silent CW FM sonar. In addition to the code modulation parameters, the magnitude of this error is influenced by the received input acoustic noise. The article shows the dependence of the input signal-to-noise ratio and the sound signal parameters on the target distance measurement error and the detection conditions, such as the output signal-to-noise ratio and the side lobe level. The results of the analysis were compared to the same parameters of the CW FM silent sonar without code modulation.
Non-destructive Diagnostics of the Floor in the Gdańsk Crane Using Ground Penetrating Radar = Diagnostyka nieniszcząca posadzki w gdańskim Żurawiu z zastosowaniem metody georadarowej
- Monika Zielińska
- Magdalena Rucka
- Erwin Wojtczak
- Tomasz Ciborowski
- Michał Steffens
2023 Full text Wiadomości Konserwatorskie
This paper presents the results of a ground penetrating radar (GPR) survey carried out at the Crane in Gdańsk. The measurements were conducted on the floor of the southern and northern towers. The aim of the experiment is to assess the possibility of detecting anomalies beneath the floor. The surveys were carried out in a non-destructive manner, using a georadar unit with 2 GHz and 400/900 MHz antennas. This paper compares the tomographic maps and echograms (B-scans) obtained from both measurements. In view of the ongoing renovation of this monument of great historical importance, it was possible to compare the results obtained with the elements uncovered during the excavation. The paper proves the effectiveness of using the GPR method to detect elements such as wooden beams, pipes, stone substructures or manholes in the ground. The superiority of the 2 GHz antenna was also demonstrated for the detection of deeper elements.
Non-ergodic fragmentation upon collision-induced activation of cysteine–water cluster cations
- Lukas Tiefenthaler
- Paul Scheier
- Ewa Erdmann
- Néstor Aguirre
- Sergio Díaz-Tendero
- Thomas F. M. Luxford
- Jaroslav Kočišek
2023 Full text PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Cysteine–water cluster cations Cys(H2O)3,6 + and Cys(H2O)3,6H+ are assembled in He droplets and probed by tandem mass spectrometry with collision-induced activation. Benchmark experimental data for this biologically important system are complemented with theory to elucidate the details of the collisioninduced activation process. Experimental energy thresholds for successive release of water are compared to water dissociation energies from DFT calculations showing that clusters do not only fragment exclusively by sequential emission of single water molecules but also by the release of small water clusters. Release of clustered water is observed also in the ADMP (atom centered density matrix propagation) molecular dynamics model of small Cys(H2O)3 + and Cys(H2O)3H+ clusters. For large clusters Cys(H2O)6 + and Cys(H2O)6H+ the less computationally demanding statistical Microcanonical Metropolis Monte–Carlo method (M3C) is used to model the experimental fragmentation patterns. We are able to detail the energy redistribution in clusters upon collision activation. In the present case, about two thirds of the collision energy redistribute via an ergodic process, while the remaining one third is transferred into a non-ergodic channel leading to ejection of a single water molecule from the cluster. In contrast to molecular fragmentation, which can be well described by statistical models, modelling of collisioninduced activation of weakly bound clusters requires inclusion of non-ergodic processes.
Nonlinearity shaping in nanostructured glass-diamond hybrid materials for optical fiber preforms
- Grzegorz Stępniewski
- Pascal Hänzi
- Adam Filipkowski
- Monika Janik
- Mariusz Mrózek
- Yuriy Stepanenko
- Robert Bogdanowicz
- Valerio Romano
- Alexander Heidt
- Ryszard Buczyński
- Mariusz Klimczak
2023 CARBON
Nanodiamond integration with optical fibers has proved a compelling methodology for magneto-optics. We reveal that the applicability of nanodiamonds in nonlinear optics goes beyond the previous demonstrations of frequency converters. Instead, we exploit the recently reported volumetric integration of nanodiamonds along the optical fiber core and show that the nonlinear response of glasses can be manipulated by nanodiamonds. By taking the mature z-scan approach we measure the nonlinear absorption and nonlinear refraction of three dielectric materials containing nanodiamonds in different concentrations and sizes. The work begins with nanodiamond-water suspensions, which offer the advantage of rapidly assessing the dependence of the nonlinear refractive index on the nano-particle concentration and size. Subsequently we investigate two fiber preforms based on silica and soft glass doped with nanodiamonds to evaluate the feasibility of nonlinearity shaping. We achieve a nearly 20% reduction of the nonlinear refractive index of fused silica containing trace amounts of nanodiamonds relative to a pristine reference. The demonstration of such a noticeable impact on the nonlinear response of the key optical material widely accepted by ultrafast optics practitioners provides a guideline for future work on the novel concept of negative nonlinearity fibers, which could disrupt the established chromatic dispersion-nonlinearity landscape.