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Recent items
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Ochrona i konserwacja historycznej architektury modernistycznej Gdyni
- Robert Hirsch
W książce opisano różnorodne działania związane z ochroną i konserwacją architektury modernistycznej Gdyni na podstawie kilkunastu lat doświadczeń autora. Scharakteryzowano system ochrony, a także problemy konserwacji od skali miasta, aż do różnych detali wykończeniowych. Przedstawiono wiele nieznanych do tej pory rozwiązań estetycznych, związanych z wykańczaniem budynków modernistycznych. Wykazano, że elewacje modernistyczne w Gdyni miały jasne kolory i często barwne detale, ale prawie nigdy nie były białe. Nie należy więc traktować dosłownie popularnego określenia "Biała Gdynia" stosowanego w odniesieniu do historycznej zabudowy .
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Ochrona katodowa stali zbrojeniowej w długoletnim okresie eksploatacji
- Marcin Majewski
- Anna Banaś
Zapobieganie powstawaniu ognisk korozji w zbrojeniu konstrukcji żelbetowych jest jednym z głównych czynników, które pozwalają na długą i niezawodną ich eksploatację. W artykule przedstawiono mechanizm działania protektorów cynkowych na podstawie przeprowadzonych badań in situ. Przedstawione badania wskazują, że ochrona katodowa z wykorzystaniem polskich protektorów cynkowych TOP ZINC wykazuje bardzo sprawne działanie.
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Oddziaływania międzycząsteczkowe w wybranych układach trójskładnikowych: woda - osmolit - model łańcucha białkowego
- Emilia Kaczkowska
W niniejszej rozprawie przedstawione zostały wyniki moich prac nad oddziaływaniami międzycząsteczkowych w wodnych układach osmolitów i białek. Wykorzystałam równolegle dwa kierunki badań: spektroskopię w podczerwieni (FTIR) oraz badania wolumetryczne i akustyczne. Mając możliwość śledzenia formowania się włókien amyloidowych, postanowiłam zbadać również wpływ wytypowanych osmolitów na proces formowania się włókien białkowych. Najważniejszym wnioskiem wynikającym z analizy pomiarów spektroskopowych FTIR układów osmolit-woda-N-metyloacetamid (NMA- model białka) jest bardzo mały wpływ (lub jego brak) osmolitów stabilizujących na strukturę oscylacyjną NMA. Denaturanty natomiast wyraźnie zmieniają widma NMA, co świadczy, że oddziaływują one bezpośrednio z NMA, w przeciwieństwie do stabilizatorów. Pomiary wolumetryczne i akustyczne dla zaproponowanego układu 3-składnikowego, również wykazały wyraźne różnice dla obu typów osmolitów. Graniczne pozorne molowe ściśliwości adiabatyczne oraz współczynniki oddziaływań w modelu McMillan-Mayer'a najwyraźniej wskazują stabilizujące i destabilizujące działanie badanych osmolitów_ Badania procesu tworzenia się włókien z lizozymu białka jaja kurzego wykazują różnice w intensywności fluorescencji, rozproszeniu i morfologii struktur powstających z białka w obecności osmolitów stabilizujących lub destabilizujących.
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Odpowiedź komórkowa indukowana przez niesymetryczne bisakrydyny skoniugowane z nanocząstkami w komórkach ludzkich raków okrężnicy i płuc
- Joanna Pilch
Pomimo znaczącego postępu w terapii nowotworów, wciąż pozostają one drugą przyczyną umieralności na świecie. Związane jest to przede wszystkim z brakiem istotnych różnic pomiędzy komórkami nowotworowymi a prawidłowymi, co przekłada się na problemy z terapią. Ponadto, chemioterapia często związana jest z dystrybucją silnie toksycznych związków, w dawkach które mogą powodować niespecyficzne działanie leku. W celu podniesienia specyficzności oraz selektywności chemioterapeutyków względem komórek nowotworowych poszukiwane są nowe metody ich dostarczania do komórek guza. W niniejszej pracy doktorskiej zbadałam wpływ skoniugowania pochodnych niesymetrycznych bisakrydyn (UAs) z nanocząstkami (m. in. kropkami kwantowymi, QDs) na ich cytotoksyczność oraz odpowiedź biologiczną, jaką indukują w komórkach nowotworu płuc oraz jelita grubego. Wykazałam, że skoniugowanie UAs z QDs (QDs UAs) zwiększa aktywność cytotoksyczną tych związków wobec komórek nowotworu płuc, jednocześnie chroniąc komórki prawidłowe przed toksycznym działaniem związku. Zastosowanie QDs jako platform transportujących leki pozwoliło na dostarczenie większej ilości związku do komórek. Ponadto, skoniugowanie UAs z QDs nie zmieniło znacząco rodzaju indukowanej odpowiedzi biologicznej, jednakże wpłynęło na jej poziom. Nieskoniugowane QDs nie były cytotoksyczne oraz nie indukowały istotnych zmian w komórkach badanych linii.
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Odwzorowanie właściwości energetycznych silników spalinowych pojazdów użytkowych z wykorzystaniem pomiarów trakcyjnych
- Oskar Wysocki
Przedmiotem rozprawy jest odwzorowanie właściwości energetycznych sinika spalinowego z wykorzystaniem danych pomiarowych, uzyskanych podczas bieżącej eksploatacji pojazdu użytkowego. W pierwszej części pracy omówione zostały podstawy działania pojazdów użytkowych oraz występowanie stanów statycznych i dynamicznych podczas rzeczywistej eksploatacji silnika. Następnie omówiono metody odwzorowania charakterystyk silnika spalinowego. Jako alternatywne do dotychczasowo stosowanego dopasowywania funkcją wielomianową, zaproponowano podejście na bazie Uczenia Maszynowego (K-Najbliższych Sąsiadów oraz Sztuczne Sieci Neuronowe). W części badawczej, przeanalizowano dobór metod odwzorowania przy wykorzystaniu wyników badań stanowiskowych, traktowanych jako referencyjne. Stanowisko pomiarowe zostało specjalnie w tym celu zaprojektowane przez autora oraz wykonane w firmie Zoeller Tech. Następnie aplikując wcześniej przeanalizowane metody, odwzorowano charakterystykę silnika pojazdu użytkowego przy użyciu danych trakcyjnych pochodzących z jednego dnia pracy pojazdu. W ostatnim rozdziale zaprezentowano wykorzystanie odwzorowanej charakterystyki w celu oceny sprawności eksploatacyjnej układu napędowego śmieciarki.
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Offshore benthic habitat mapping based on object-based image analysis and geomorphometric approach. A case study from the Slupsk Bank, Southern Baltic Sea
- Lukasz Janowski
- Radoslaw Wroblewski
- Janusz Dworniczak
- Mateusz Kolakowski
- Karolina Rogowska
- Michał Wójcik
- Juliusz Gajewski
Benthic habitat mapping is a rapidly growing field of underwater remote sensing studies. This study provides the first insight for high-resolution hydroacoustic surveys in the Slupsk Bank Natura 2000 site, one of the most valuable sites in the Polish Exclusive Zone of the Southern Baltic. This study developed a quick and transparent, automatic classification workflow based on multibeam echosounder and side-scan sonar surveys to classify benthic habitats in eight study sites within the Slupsk Bank. Different predictor variables, four supervised classifiers, and the generalisation approach, improving the accuracy of the developed model were evaluated. The results suggested a very high significance for the classification performance of specific geomorphometric features that were not used in benthic habitat mapping before. These include, e.g., Fuzzy Landform Element Classification, Multiresolution Index of the Valley Bottom Flatness, and Multiresolution Index of the Ridge Top Flatness. Comparison of classification results with manual maps demonstrated that Random Forest had the highest performance of four tested supervised classifiers. Because the current needs include benthic habitat mapping for the whole area of the Polish Exclusive Economic Zone, the key findings of this study may be further applied to extensive areas in the Polish waters and other vast areas worldwide.
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Ogólnopolski Konkurs Plastyczny dla Dzieci i Młodzieży ‘DOM KASZUBSKI NA ZIEMI ZABORSKIEJ. smaki dziedzictwa’
- Agnieszka Kurkowska
Celem konkursu było upowszechnianie dziedzictwa Ziemi Zaborskiej, zarówno kulturowe jak i przyrodniczego ze szczególnym uwzględnieniem uwarunkowań lokalnych. Tematem konkursu było przedstawienie smaków dziedzictwa związanych z domem kaszubskim na Ziemi Zaborskiej.
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OGÓLNOPOLSKI PLENER ARTYSTYCZNY DOM KASZUBSKI NA ZIEMI ZABORSKIEJ. smaki dziedzictwa
- Agnieszka Kurkowska
Plener tematycznie dotyczył wysmakowanej architektury kaszubskiej na ziemi zaborskiej: domu kaszubskiego, zagrody i szerzej krajobrazu w kontekście tytułowych ‘smaków dziedzictwa’. Przedogródek, sad, ogród warzywny, pole, łąka, las i jezioro nadają smak życiu w kaszubskim domu. Ale rozumiejąc ‘smak dziedzictwa’ bardziej konceptualnie, karmimy zmysłu urokiem regionu, harmonią krajobrazu kulturowego i przyrodniczego oraz unikalną zabudową historyczną wsi kaszubskiej wraz z towarzyszącymi budynkom elementami przyrodniczymi i wypełniającymi je przedmiotami rzemieślniczymi. To całokształt ‘smaków dziedzictwa’. Tematem wiodącym były Kaszuby, skupiając uwagę na regionie zaborskim.
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Ograniczenia i koszty wdrożenia systemu open data
- Aleksander Orłowski
Przedstawienie kosztów i ograniczeń wdrażania open data w polskich urzędach miejskich.
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OIL-ASSISTED THERMO-MECHANICAL RECLAMATION OF GROUND TIRE RUBBER
- Aleksander Hejna
- Paulina Kosmela
- Adam Olszewski
- Łukasz Zedler
- Krzysztof Formela
Nowadays, it is crucial to seek for the methods of by-products and waste utilization, considering both environmental and economic factors. The example of waste material generated in the massive amounts, which requires the attention is ground tire rubber generated during recycling of post-consumer car tires. It can be applied as a filler into different polymer matrices, but to enhance its effectivity proper modifications should be performed. In the presented paper, we investigated the oil-assisted thermo-mechanical treatment of ground tire rubber in twin-screw extruder. Changes in the chemical structure were determined by the measurement of hydroxyl numbers of modified rubber. Moreover, application of oils enhanced thermal stability of treated ground tire rubber
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On analysis of double-impact test of 1500-kg vehicle into w-beam guardrail system
- Krzysztof Wilde
- Dawid Bruski
- Stanisław Burzyński
- Jacek Chróścielewski
- Łukasz Pachocki
- Wojciech Witkowski
Every day on roads many scenarios of accidents may occur. One of the measures to minimize their consequences is road safety barriers. Finite Element analyses are being increasingly used to support the physical testing of these devices. The paper addresses the issue of a secondary impact into the previously damaged w-beam guardrail system. This situation belongs to one of the most dangerous which can happen on roads and may cause serious hazards, especially if the vehicle goes through the barrier. To evaluate the crashworthiness of the road barrier, the computational model of the crash test was developed and validated against the full-scale crash test. Then two simulations of TB32 crash tests were conducted on both damaged and undamaged road barriers to assess the influence of damage on the effectiveness of the safety system during vehicular impact. The study has revealed that the partially damaged system preserved some of its original functionality.
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On asymptotic periodicity of kernel double Markovian operators
- Wojciech Bartoszek
- Michał Krzemiński
It is proved that a kernel, doubly Markovian operator T is asymptotically periodic if and only if its deterministic σ-field Σd(T)(equivalently Σd(T∗)) is finite. It follows that kernel doubly Markovian operator T is asymptotically periodic if and only if T∗ is asymptotically periodic.
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On Decomposition-Based Surrogate-Assisted Optimization of Leaky Wave Antenna Input Characteristics for Beam Scanning Applications
- Mehmet Belen
- Peyman Mahouti
- Sławomir Kozieł
- Alper Caliskan
- Jakub Szczepański
Recent years have witnessed a growing interest in reconfigurable antenna systems. Travelling wave antennas (TWAs) and leaky wave antennas (LWAs) are representative examples of structures featuring a great level of flexibility (e.g., straightforward implementation of beam scanning), relatively simple geometrical structure, low profile, and low fabrication cost. Notwithstanding, the design process of TWAs/LWAs is a challenging endeavor because efficient handling of their electrical/field characteristics requires repetitive full-wave electromagnetic (EM) analyses, which is computationally expensive. In this paper, a novel approach to rapid optimization of LWA’s input characteristics is proposed, based on structure decomposition and rendition of fast surrogate models of the antenna unit cells. The surrogates are combined into a single metamodel representing antenna input characteristics, which enables low-cost adjustment of the geometry parameters. The presented methodology is demonstrated through the design of several LWAs operating in the frequency bands of 8.2 GHz to 11.2 GHz, 6.2 GHz to 8.2 GHz, and 3.8 GHz to 4.7 GHz. Numerical results are validated through physical measurements of the fabricated array prototype.
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On EM-driven size reduction of antenna structures with explicit constraint handling
- Sławomir Kozieł
- Sławomir Kozieł
Simulation-driven miniaturization of antenna components is a challenging task mainly due to the presence of expensive constraints, evaluation of which involves full-wave electromagnetic (EM) analysis. The recommended approach is implicit constraint handling using penalty functions, which, however, requires a meticulous selection of penalty coefficients, instrumental in ensuring optimization process reliability. This paper proposes a novel size reduction technique with explicit handling of design constraints. Our approach employs trust-region gradient-based procedure as an underlying optimization engine, and adjusts the search radius based on assessing the quality of representing constraints by auxiliary linear expansion models (versus their exact evaluation through EM analysis), rather than based on the quality of objective rendition. This unconventional utilization of trust region framework leads to a procedure that is demonstrably superior over implicit methods, as indicated by comprehensive numerical studies involving four broadband antennas, and benchmarking against state-of-the-art techniques. The two most attractive features of our methodology are simplicity, and no need to tune the algorithm for a specific problem at hand.
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On Fast Multi-objective Optimization of Antenna Structures Using Pareto Front Triangulation and Inverse Surrogates
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
- Leifur Leifsson
Design of contemporary antenna systems is a challenging endeavor, where conceptual developments and initial parametric studies, interleaved with topology evolution, are followed by a meticulous adjustment of the structure dimensions. The latter is necessary to boost the antenna performance as much as possible, and often requires handling several and often conflicting objectives, pertinent to both electrical and field properties of the structure. Unless the designer’s priorities are already established, multi-objective optimization (MO) is the preferred way of yielding the most comprehensive information about the best available design trade-offs. Notwithstanding, MO of antennas has to be carried out at the level of full-wave electromagnetic (EM) simulation models which poses serious difficulties due to high computational costs of the process. Popular mitigation methods include surrogate-assisted procedures; however, rendering reliable metamodels is problematic at higher-dimensional parameter spaces. This paper proposes a simple yet efficient methodology for multi-objective design of antenna structures, which is based on sequential identification of the Pareto-optimal points using inverse surrogates, and triangulation of the already acquired Pareto front representation. The two major benefits of the presented procedure are low computational complexity, and uniformity of the produced Pareto set, as demonstrated using two microstrip structures, a wideband monopole and a planar quasi-Yagi. In both cases, ten-element Pareto sets are generated at the cost of only a few hundreds of EM analyses of the respective devices. At the same time, the savings over the state-of-the-art surrogate-based MO algorithm are as high as seventy percent.
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On FEM analysis of Cosserat-type stiffened shells. Static and stability linear analysis
- Stanisław Burzyński
The present research investigates the theory and numerical analysis of shells stiffened with beams in the framework based on the geometrically exact theories of shells and beams. Shell’s and beam’s kinematics are described by the Cosserat surface and the Cosserat rod respectively, which are consistent including deformation and strain measures. A FEM approximation of the virtual work principle leads to the conforming shell and beam FE with 6 DoFs (including the drilling rotation for shells) in each node. Examples of static and stability linear analyses are included. Novel design formulas for the stability of stiffened shells are included.
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On forced vibrations of piezo-flexomagnetic nano-actuator beams
- Mohammad Malikan
- Victor Eremeev
The effect of excitation frequency on the piezomagnetic Euler-Bernoulli nanobeam taking the flexomagnetic material phenomenon into consideration is investigated in this chapter. The magnetization with strain gradients creates flexomagneticity. We couple simultaneously the piezomagnetic and flexomagnetic properties in an inverse magnetization. Resemble the flexoelectricity, the flexomagneticity is also size-dependent. So, it has further notable influence at a small size. Here, a dynamic loading is transversely acted on the nanobeam. This loading plays the role of the excitation force. Moreover, we combine the equilibrium equations with the nonlocal model of strain gradient elasticity (NSGT). Afterward, we impose the Hamilton’s principle for having the governing equations. The attained linear differential equation is transferred into an algebraic equation by using Galerkin weighted residual method. Then, the gained linear algebraic equation is solved which leads to numerical values of dynamic deflections.
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On geometry parameterization for simulation-driven design closure of antenna structures
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
Full-wave electromagnetic (EM) simulation tools have become ubiquitous in antenna design, especially final tuning of geometry parameters. From the reliability standpoint, the recommended realization of EM-driven design is through rigorous numerical optimization. It is a challenging endeavor with the major issues related to the high computational cost of the process, but also the necessity of handling several objectives and constraints over often highly-dimensional parameter spaces. From the numerical perspective, making decisions about the formulation of the optimization problem, the approach to handling the design constraints, but also parameterization of the antenna geometry, are all non-trivial. At the same time, these issues are interleaved, and may play an important role in the performance and reliability of the simulation-based design closure process. This paper demonstrates that the approach to arranging the structure parameterization (e.g., the use of absolute or relative parameters) may have a major effect of the optimization outcome. Our investigations are carried out using three broadband monopole antennas optimized under different scenarios and using different parameterizations. In particular, the results indicate that relative parameterization is preferred for optimization of input characteristics, whereas absolute parameterization is more suitable for size reduction.
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On Guard for Lighting Quality. The establishment of the first association of professional lighting designers
- Karolina Zielińska-Dąbkowska
Not many people in the lighting community are aware of the fact, that after electricity was invented and in general use in the United States from the late nineteenth century, only electrical engineers were responsible for the illumination of architecture. After 1906, when the Illuminating Engineering Society of North America (IESNA) was established in the USA, companies and individuals professionally involved in the field of gas lighting and natural light, were first brought together. However, this new field quickly became dominated by people applying electric light in their projects. Members of this young discipline were mindful from the beginning, that a collaboration with architects was decisive and of great importance for the future development of lighting as a profession.
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On nonlinear dilatational strain gradient elasticity
- Victor Eremeev
- Antonio Cazzani
- Francesco dell'Isola
We call nonlinear dilatational strain gradient elasticity the theory in which the specific class of dilatational second gradient continua is considered: those whose deformation energy depends, in an objective way, on the gradient of placement and on the gradient of the determinant of the gradient of placement. It is an interesting particular case of complete Toupin–Mindlin nonlinear strain gradient elasticity: indeed, in it, the only second gradient effects are due to the inhomogeneous dilatation state of the considered deformable body. The dilatational second gradient continua are strictly related to other generalized models with scalar (one-dimensional) microstructure as those considered in poroelasticity. They could be also regarded to be the result of a kind of “solidification” of the strain gradient fluids known as Korteweg or Cahn–Hilliard fluids. Using the variational approach we derive, for dilatational second gradient continua the Euler–Lagrange equilibrium conditions in both Lagrangian and Eulerian descriptions. In particular, we show that the considered continua can support contact forces concentrated on edges but also on surface curves in the faces of piecewise orientable contact surfaces. The conditions characterizing the possible externally applicable double forces and curve forces are found and examined in detail. As a result of linearization the case of small deformations is also presented. The peculiarities of the model is illustrated through axial deformations of a thick-walled elastic tube and the propagation of dilatational waves.
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On possible applications of media described by fractional-order models in electromagnetic cloaking
- Tomasz Stefański
The purpose of this paper is to open a scientific discussion on possible applications of media described by fractional-order (FO) models (FOMs) in electromagnetic cloaking. A 2-D cloak based on active sources and the surface equivalence theorem is simulated. It employs a medium described by FOM in communication with sources cancelling the scattered field. A perfect electromagnetic active cloak is thereby demonstrated with the use of a finite-difference time-domain method combined with a simulation algorithm of non-monochromatic wave propagation in the media described by FOM. The application of constitutive relations based on FOMs in Maxwell’s equations provides solutions which correspond to the results reported for the time-fractional diffusion-wave equation, which is non-relativistic, like the classical diffusion equation. This property is employed in the presented cloaking scheme for communication with active current sources around the cloak, which cancel the scattered field of an object inside the cloak. Although in the real world perfect invisibility is impossible to obtain due to the constraint of light speed, it is possible to obtain a perfect cloak in theoretical considerations by using FO formulation of electromagnetism. It is worth noticing that numerous literature sources experimentally confirm the existence of electromagnetic media described by FOMs; hence, the presented numerical results should hopefully stimulate further investigations related to applications of FOMs in electromagnetic cloaking.
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On the Application of Magnetoacoustic Emission for a Nondestructive Assessment of the Post Welding Heat Treatment of High Chromium Steel Weld Seams
- Leszek Piotrowski
- Marek Chmielewski
- Grzegorz Golański
- K. Wojsyk
The paper analyses the possibility of post weld heat treatment (PWHT) quality assessment with the help of magnetoacoustic emission (MAE) signal measurements. Two welded superheater tubes, made of high chromium VM12 steel, were analysed—as welded and heat treated one. The analysed sample in the as welded state exhibited significantly higher hardness, accompanied by a big difference in the MAE signal intensity (of order of about 50%). In order to explain that, the influence of tempering on the MAE signal intensity is demonstrated for the very similar X20CrMoV12.1 steel. It is shown that the observed increase of the MAE intensity as a function of annealing time is directly correlated with the change in hardness. The as described dependence allows to propose a method based on the MAE signal measurements as a new tool for the PWHT assessment.
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On the Characteristic Graph of a Discrete Symmetric Channel
- Dariusz Dereniowski
- Marcin Jurkiewicz
We present some characterizations of characteristic graphs of row and/or column symmetric channels. We also give a polynomial-time algorithm that decides whether there exists a discrete symmetric channel whose characteristic graph is equal to a given input graph. In addition, we show several applications of our results.
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On the current state of dovetail wall-corner joints in wooden Greek Catholic churches in Polish Subcarpathia with structural and sensitivity analyses
- Izabela Lubowiecka
- Tomasz Zybała
- Grzegorz Bukal
- Marcin Krajewski
- Marcin Kujawa
- Paweł Kłosowski
This paper describes the current condition of some dovetail joints which form the wall corners of two Greek Catholic churches of wooden construction in Polish Subcarpathia. It also gives the historical background of the sacral architecture of that region. The two structures, which represent the same type of log corner joints are situated in Chotylub and Cewków. The buildings were examined e.g. for damage, wood moisture content, out-of-plane deviations and changes in the geometry of the walls. The study is based on in-situ examination and structural analysis of the joints. Finite element simulations of the statics of joints built of old, and mixture of old and new, wood are performed in order to show how the change of material properties affects their structural behaviour. Also a sensitivity analysis is performed to describe the effect on potential repairs that combining old damp wood with new and dry joint members might have.
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On the generalized model of shell structures with functional cross-sections
- Shahriar Dastjerdi
- Mohammad Malikan
- Victor Eremeev
- Bekir Akgöz
- Ömer Civalek
In the present study, a single general formulation has been presented for the analysis of various shell-shaped structures. The proposed model is comprehensive and a variety of theories can be used based on it. The cross-section of the shell structure can be arbitrarily analyzed with the presented equations. In other words, various types of shell structures, including cylindrical, conical, spherical, elliptical, hyperbolic, parabolic, and any non-geometric structure with functional cross-section, can be modeled mechanically with only one partial differential equation system. The obtained equations have been solved by applying SAPM semi-analytical solution method. In order to present a comprehensive research, dynamic nonlinear analysis is considered. The variation of material properties through the thickness has been assumed as functionally graded and its effect on the strength of the shell structure with the functional cross-section has been investigated. The numerical results have been compared with available papers and also with FEM results for some structures that there is no paper available for validation. Different types of shell structures have been studied in terms of cross-sectional shape and properties. Finally, the effects of some important factors on the results such as boundary conditions, nonlinear analysis, dynamic analysis, and rotation of the structure around its central axis have been conducted thoroughly. This study and its original governing equations can be considered as a comprehensive reference for mechanical analysis of various shell structures with functional cross-sectional shape.
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On the influence of a surface roughness on propagation of anti-plane short-length localized waves in a medium with surface coating
- Gennadi Mikhasev
- Marina Botogova
- Victor Eremeev
We discuss the propagation of localized surface waves in the framework of the linear Gurtin–Murdoch surface elasticity and taking into account a roughness of a free boundary. We derive a boundary-value problem for anti-plane motions with curvilinear boundary and surface stresses. Using the asymptotic technique developed earlier, we obtain the form of a localized wave and analyze its amplitude evolution. As the main result we present the dependence of the wave amplitude on the roughness magnitude. The presented results could be used for non-destructive evaluation of the surface microstructure using surface waves-based devices. In particular, measuring the decay rate with the depth one can estimate roughness of a surface and appearance of new surface defects.
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On the mechanism of photocatalytic reactions on CuxO@TiO2 core–shell photocatalysts
- Kunlei Wang
- Zuzanna Bielan
- Maya Endo-Kimura
- Marcin Janczarek
- Dong Zhang
- Damian Kowalski
- Anna Zielińska-Jurek
- Agata Markowska-Szczupak
- Bunsho Ohtani
- Ewa Kowalska
Titania (titanium(IV) oxide) is a highly active, stable, cheap and abundant photocatalyst, and is thus commonly applied in various environmental applications. However, two main shortcomings of titania, i.e., charge carrier recombination and inactivity under visible-light (vis) irradiation, should be overcome for widespread commercialization. Accordingly, titania has been doped, surface modified and coupled with various ions/compounds, including narrower bandgap semiconductors, such as oxides of copper and silver. Unfortunately, these oxides are not as stable as titania, and thus loss of activity under long-term irradiation (photo-corrosion) has been observed. Therefore, this study has focused on the preparation of stable coupled photocatalysts, i.e., CuxO@TiO2 core–shell nanostructures, by the microemulsion method from commercial Cu2O as a core and TiO2 (ST01-fine anatase) as a shell. The photocatalysts have been characterized by DRS, SEM, TEM, XRD, XPS and reversed double-beam photo-acoustic spectroscopy (RDB-PAS) methods, and activity tests under UV (anaerobic dehydrogenation of methanol and oxidative decomposition of acetic acid) and vis (phenol oxidation) irradiation. The higher activities of coupled photocatalysts than their counterparts have been found in all studied systems under UV/vis irradiation. Moreover, long-term experiments (10 h) have shown high stability of CuxO@TiO2. However, the change of oxidation state of copper has also been observed, i.e., to negative and positive values, confirming the charge transfer according to the Z-scheme under UV irradiation and type-II heterojunction under vis irradiation, respectively. The property-governed activity and the mechanism have been discussed in detail.
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On the problem of optimised allocation of water quality sensors and actuators in DWDS
- Tomasz Zubowicz
- Rafał Łangowski
The problems of water quality sensors and actuators placement in drinking water distribution systems (DWDSs) are addressed as separate, primarily. However, against the background of control systems theory, the nature of DWDSs dynamics indicates that these both problems are interdependent and impact the design of related water quality monitoring and control structures and algorithms. The research work presented in this paper is to investigate the state-of-the-art in this field and discuss the problems of water quality sensors and actuators placement within DWDS and to highlight the potential benefits of considering the joint task of their allocation.
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On thermal stability of piezo-flexomagnetic microbeams considering different temperature distributions
- Mohammad Malikan
- Tomasz Wiczenbach
- Victor Eremeev
By relying on the Euler–Bernoulli beam model and energy variational formula, we indicate critical temperature causes in the buckling of piezo-flexomagnetic microscale beams. The corresponding size-dependent approach is underlying as a second strain gradient theory. Small deformations of elastic solids are assessed, and the mathematical discussion is linear. Regardless of the pyromagnetic effects, the thermal loading of the thermal environment varies in three states along with the thickness, which is linear, uniform, and parabolic forms. We then establish the results by developing consistent shape functions that independently evaluate boundary conditions. Next, we analytically develop and explore the effective properties of the studied beam concerning vital factors. It was achieved that piezomagnetic-flexomagnetic microbeams are more affected by the thermal environment while the thermal loading is parabolically distributed across the thickness, particularly when the boundaries involve simple supports.
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On thio‐substituted N‐heterocyclic arsines
- Johannes Bender
- Agnieszka Skowrońska
- Anna Dołęga
- Martin Nieger
- Dietrich Gudat
Metathesis of N-heterocyclic chloroarsines with sulfur-based nucleophiles furnished thio-substituted 1,3,2-diazarsolidines and 1,3,2-diazarsolenes. Crystallographic and NMR spectroscopic studies revealed that a thiocyanato-diazarsolene exhibits a salt-like structure composed of weakly interacting thiocyanate and arsenium ions, while the remaining products formed neutral molecules. The structural data indicate that the heterocyclic framework induces an elongation of exocyclic As−S bonds that is more prominent in diazarsolenes than in diazarsolidines and parallels the bond polarisation effect established for N-heterocyclic phosphines. The NMR data suggest that diazarsolenes undergo facile inversion of the pyramidal configuration at arsenic, which was successfully modelled by DFT studies.
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On topology optimization of large deformation contact-aided shape morphing compliant mechanisms
- Prabhat Kumar
- Roger Sauer
- Anupam Saxena
A topology optimization approach for designing large deformation contact-aided shape morphing compliant mechanisms is presented. Such mechanisms can be used in varying operating conditions. Design domains are described by regular hexagonal elements. Negative circular masks are employed to perform dual task, i.e., to decide material states of each element and also, to generate rigid contact surfaces. Each mask is characterized by five design variables, which are mutated by a zero-order based hill-climbing optimizer. Geometric and material nonlinearities are considered. Continuity in normals to boundaries of the candidate designs is ensured using a boundary resolution and smoothing scheme. Nonlinear mechanical equilibrium equations are solved using the Newton–Raphson method. An updated Lagrange approach in association with segment-to-segment contact method is employed for the contact formulation. Both mutual and self contact modes are permitted. Efficacy of the approach is demonstrated by designing four contact-aided shape morphing compliant mechanisms for different desired curves. Performance of the deformed profiles is verified using a commercial software. The effect of frictional contact surface on the actual profile is also studied.
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On weak solutions of boundary value problems within the surface elasticity of Nth order
- Victor Eremeev
- Leonid Lebedev
- Michael Cloud
A study of existence and uniqueness of weak solutions to boundary value problems describing an elastic body with weakly nonlocal surface elasticity is presented. The chosen model incorporates the surface strain energy as a quadratic function of the surface strain tensor and the surface deformation gradients up to Nth order. The virtual work principle, extended for higher‐order strain gradient media, serves as a basis for defining the weak solution. In order to characterize the smoothness of such solutions, certain energy functional spaces of Sobolev type are introduced. Compared with the solutions obtained in classical linear elasticity, weak solutions for solids with surface stresses are smoother on the boundary; more precisely, a weak solution belongs to 1()∩() where ⊂≡ and ⊂ℝ3 .
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On Wrinkling in Sandwich Panels with an Orthotropic Core
- Zbigniew Pozorski
- Jolanta Pozorska
- Ireneusz Kreja
- Łukasz Smakosz
This paper deals with the local loss of stability (wrinkling) problem of a thin facing of a sandwich panel. Classical solutions to the problem of facing instability resting on a homogeneous and isotropic substructure (a core) are compared. The relations between strain energy components associated with different forms of core deformations are discussed. Next, a new solution for the orthotropic core is presented in detail, which is consistent with the classic solution for the isotropic core. Selected numerical examples confirm the correctness of the analytical formulas. In the last part, parametric analyses are carried out to illustrate the sensitivity of wrinkling stress to a change in the material parameters of the core. These analyses illustrate the possibility of using the equations derived in the article for the variability of Poisson’s ratio from -1 to 1 and for material parameters strongly deviating from isotropy.
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Onboard Energy Storage and Power Management Systems forAll-Electric Cargo Vessel Concept
- Dariusz Karkosiński
- Wojciech Aleksander Rosiński
- Piotr Deinrych
- Szymon Potrykus
This paper presents an innovative approach to the design of a forthcoming, fully electric-powered cargo vessel. This work begins by defining problems that need to be solved when designingvessels of this kind. Using available literature and market research, a solution for the design of apower management system and a battery management system for a cargo vessel of up to 1504 TEUcapacity was developed. The proposed solution contains an innovative approach with three parallelenergy sources. The solution takes into consideration the possible necessity for zero-emission workwith the optional function of operation as an autonomous vessel. Energy storage system based onlithium-ion battery banks with a possibility of expanding the capacity is also described in this work asit is the core part of the proposed solution. It is estimated that the operation range for zero-emissionwork mode of up to 136 nautical miles can be achieved through the application of all fore-mentioned parts.
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Ongoing progress on novel nanocomposite membranes for the separation of heavy metals from contaminated water
- Roberto Castro Munoz
- Luisa Loreti González-Melgoza
- Octavio García-Depraect
Membranes, as the primary separation element of membrane-based processes, have greatly attracted the attention of researchers in several water treatment applications, including wastewater treatment, water purification, water disinfection, toxic and non-toxic chemical molecules, heavy metals, among others. Today, the removal of heavy metals from water has become challenging, in which chemical engineers are approaching new materials in membrane technologies. Therefore, the current review elucidates the progress of using different concepts of membranes and potential novel materials for such separations, identifying that polymeric membranes can exhibit a removal efficiency from 77 up to 99%; while novel nanocomposite membranes are able to offer complete removal of heavy metals (up to 100%), together with unprecedented permeation rates (from 80 up to 1, 300 L m−2 h−1). Thereby, the review also addresses the highlighted literature survey of using polymeric and nanocomposite membranes for heavy metal removal, highlighting the relevant insights and denoted metal uptake mechanisms. Moreover, it gives up-to-date information related to those novel nanocomposite materials and their contribution to heavy metals separation. Finally, the concluding remarks, future perspectives, and strategies for new researchers in the field are given according to the recent findings of this comprehensive review.
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On-line assessment of oil quality during deep frying using an electronic nose and proton transfer reaction mass spectrometry
- Tomasz Majchrzak
- Wojciech Wojnowski
- Agnieszka Głowacz-Różyńska
- Andrzej Wasik
We describe a novel method for the quality assessment of oil utilized for deep frying. The method is based on the analysis of frying fumes using a custom electronic nose. The quality score could be obtained after less than 3 min of analysis and without interrupting the frying process or sampling the oil directly. The obtained results were correlated with the peroxide value using a multivariate linear regression model. The most relevant variables were selected based on heat maps and on the analysis of variance. The coefficients of determination for palm oil and rapeseed oil were 0.920 and 0.935, respectively. Real-time monitoring of selected VOCs in the frying fumes was performed using proton transfer reaction mass spectrometry. It was shown that 1-heptanol is a possible indicator of rapeseed oil’s quality. The proposed method might be used to supplement the currently available techniques and could find implementation in the non-invasive on-line assessment of frying oils’ quality during deep frying of foodstuffs
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Ontological Model for Contextual Data Defining Time Series for Emotion Recognition and Analysis
- Teresa Zawadzka
- Wojciech Waloszek
- Aleksandra Karpus
- Sara Zapalowska
- Michał Wróbel
One of the major challenges facing the field of Affective Computing is the reusability of datasets. Existing affective-related datasets are not consistent with each other, they store a variety of information in different forms, different formats, and the terms used to describe them are not unified. This paper proposes a new ontology, ROAD, as a solution to this problem, by formally describing the datasets and unifying the terms used. The developed ontology allows information about the origin and meaning of the data to be modeled, i.e., time series, representing both emotional states and features derived from biosignals. Furthermore, the ROAD ontology is extensible and not application-oriented, thus it can be used to store data from a wide range of Affective Computing experiments. The ontology was validated by modeling data obtained from one experiment on the AMIGOS dataset. The approach proposed in the paper can be used both by researchers who create new datasets or want to reuse existing ones, and for those who want to process data from experiments in a more automated way.
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Open Innovation Competence for a Future-Proof Workforce: A Comparative Study from Four European Universities
- Marita Mcphillips
- Magdalena Licznerska
Digital transformation is a key driving force of open innovation to capture and transfer knowledge inside and outside of a company’s bounds. New challenges in organizing multiple knowledge flows imply the need for increased competences related to this paradigm of future employees. In this article, we organize and aggregate the competencies required for open innovation collaboration and develop a competence profile that organizes individual competencies in an open innovation context. Based on elements of the European Entrepreneurship Competence Framework, we delineate an OI Competence Profile and list the core competencies to manage and accelerate the inflow and outflow of knowledge. We explore this profile by comparing data from 2332 students from four European universities to find differences in the distribution of OI competencies between countries. The study contributes to understanding the individual competencies that target the future OI needs of companies necessary in the context of digital transformation. It also introduces an interdisciplinary approach to integrate the research streams of management practice, open innovation, and entrepreneurial education.
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Opinia na temat celowości oraz zakresu rzeczowego remontu tokarki karuzelowej FKD-60/80. Ekspertyza techniczna opracowana na zlecenie ENEROMONTAŻ-PÓŁNOC GDYNIA S.A.
- Wojciech Blacharski
Opracowana Opinia Jednostki Naukowej dotyczyła ciężkiej tokarki karuzelowej typu FKD-60/80 ze sterowaniem CNC. Na podstawie przeprowadzonego w miejscu użytkowania tej obrabiarki audytu, dokonano oceny obecnego stanu maszyny oraz przeanalizowano przyczyny awarii, które zdarzały się w okresie jej eksploatacji. Zakres analizy przyczyn stanów awaryjnych obejmował: - awarie zespołu elektrowrzeciona oraz układów hydraulicznych zawartych w tym zespole; - obserwowane ugięcia i błędy geometryczne stołu obrotowego (oś C) ulokowanego na prowadnicy hydrostatycznej oraz ocenę dopuszczalnej obciążalności tego stołu; - problemy z napędem ruchu belki w kierunku pionowym (oś W); - usterki w układach smarowania i układach hydraulicznych; - problemy z układem sterowania. W opracowaniu określono zakres koniecznych prac remontowych oraz zaproponowano wprowadzenie działań zapobiegawczych w ramach utrzymania ruchu. Przeanalizowano również ograniczenia możliwości obróbkowych tokarki FKD-60/80 w kontekście potrzeb produkcyjnych firmy użytkującej tą maszynę. Opracowanie zawiera 28 stron, 7 rysunków i 7 fotografii.
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Opinia na temat celowości oraz zakresu rzeczowego remontu wytaczarko-frezarki płytowej typu FLF16/CNC. Ekspertyza techniczna opracowana na zlecenie ENEROMONTAŻ-PÓŁNOC GDYNIA S.A.
- Wojciech Blacharski
Opracowana Opinia Jednostki Naukowej dotyczyła ciężkiej wytaczarko-frezarki płytowej typu FLF16/CNC ze sterowaniem CNC. Na podstawie przeprowadzonego w miejscu użytkowania tej obrabiarki audytu, dokonano oceny obecnego stanu maszyny oraz przeanalizowano przyczyny awarii, które zdarzały się w okresie jej eksploatacji. Zakres analizy przyczyn problemów eksploatacyjnych i stanów awaryjnych obejmował: - awarie zespołu elektrowrzeciona oraz układów hydraulicznych zawartych w tym zespole; - usterki głowicy przechylnej do elektrowrzeciona; - usterki w układach napędowych osi liniowych, w tym osi X (ruch liniowy stojaka w kierunku poziomym, osi Y (ruch liniowy suwaka w kierunku pionowym), osi Z (ruch liniowy belki wrzeciennika); - problemy ze zbyt dużymi błędami geometrycznymi ustawienia głównych zespołów obrabiarki i niedotrzymywaniem wymagań WOT; - usterki układów smarowania i hydrauliki; - problemy z układem sterowania. W opracowaniu określono zakres prac remontowych, które byłyby konieczne dla przywrócenia maszyny do jej stanu początkowego. Wskazano również na istotne ograniczenia możliwości obróbkowych wytaczarko frezarki FLF16/CNC w kontekście aktualnych potrzeb produkcyjnych firmy użytkującej tą maszynę. Opracowanie zawiera 25 stron, 1 rysunek i 10 fotografii.
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Opioid Growth Factor and its Derivatives as Potential Non-toxic Multifunctional Anticancer and Analgesic Compounds
- Justyna Budka
- Szymon Kowalski
- Monika Chylińska
- Krystyna Dzierzbicka
- Iwona Inkielewicz-Stępniak
In this paper, we review the structure-activity relationship of OGF and its analogues. We highlight also OGF derivatives with analgesic, immunomodulatory activity and the ability to penetrate the blood-brain barrier and may be used as safe agents enhancing chemotherapy efficacy and improving quality of life in cancer patients. The reviewed papers indicate that Met-enkephalin and its analogues are interesting candidates for the development of novel, non-toxic, and endowed with an analgesic activity anticancer drugs. More preclinical and clinical studies are needed to explore these opportunities.
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Opłacalność zastosowania pompy ciepła w układach centralnego ogrzewania i ciepłej wody użytkowej
- Karol Olszewski
- Blanka Jakubowska
W artykule przedstawiono problem opłacalności ekonomicznej stosowania pompy ciepła, w układach ciepłej wody użytkowej oraz centralnego ogrzewania. Zasadność zastosowania takich źródeł ciepła w tych instalacjach spowodowana jest ogólnoświatowymi kierunkami i stopniowym odchodzeniem od konwencjonalnych źródeł energii takich jak kotły olejowe lub gazowe. Przedmiotem artykułu był budynek jednorodzinny o powierzchni użytkowej ok. 145 m2, w którym instalacja c.o. oraz c.w.u. byłaby zasilana gruntową pompą ciepła. Do analizy przyjęto dwa warianty instalacji c.o., tj. dwururową grzejnikową z rozdziałem dolnym oraz ogrzewanie podłogowe. W przypadku instalacji ciepłej wody użytkowej przyjęto jeden wariant układu centralnego przygotowaniu c.w.u. i magazynowanej w zbiorniku znajdującym się wewnątrz obudowy pompy ciepła. Do analizy opłacalności użyto metodę prostego czasu zwrotu nakładów inwestycyjnych, w której pompa ciepła została porównana z konwencjonalnym źródłem ciepła.
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Optical fiber aptasensor for label-free bacteria detection in small volumes
- Monika Janik
- Ewa Brzozowska
- Paula Czyszczoń
- Anna Celebańska
- Marcin Koba
- Andrzej Gamian
- Wojtek J. Bock
- Mateusz Śmietana
Highly sensitive devices for fast bacteria detection are sought to be developed with the task of quantifying the worldwide problem of pathogenic bacteria and thus helping to take control over spreading bacterial infections. This work concerns a sensing solution based on microcavity in-line Mach-Zehnder interferometer (μIMZI) induced in an optical fiber. Such a device exhibits ultrahigh sensitivity to refractive index changes in the microcavity. We show that for well-adjusted chemical surface functionalization combined with highly specific low-molecular-weight bioreceptor the μIMZI can also be used for efficient label-free bacteria detection. The detection capability has been shown for peptide aptamers and pathogenic E. coli O157:H7 bacteria used as a bioreceptor and a target, respectively. We have found that the sensor is capable of detecting bacteria concen-trations as low as 10 colony-forming units per mL in a sample which volume may be as small as hundreds of picoliters. The selectivity of the synthesized peptides is additionally confirmed by Enzyme-Linked Immunosor-bent Assay (ELISA). Based on the presented performance, the μIMZI sensor is one of the most sensitive and lowest-analyte-volume label-free biosensors among fiber optical platforms to date
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Optical flow method for measuring deformation of soil specimen subjected to torsional shearing
- Piotr Srokosz
- Marcin Bujko
- Marta Bocheńska
- Rafał Ossowski
In this study optical flow method was used for soil small deformation measurement in laboratory tests. The main objective was to observe how the deformation distributes along the whole height of cylindrical soil specimen subjected to torsional shearing (TS test). The experiments were conducted on dry non-cohesive soil specimens under two values of isotropic pressure. Specimens were loaded with low-amplitude cyclic torque to analyze the deformation within the small strain range (0.001–0.01%). Optical flow method variant by Ce Liu (2009) was used for motion estimation from series of images. This algorithm uses scale-invariant feature transform (SIFT) for image feature extraction and coarse-to-fine matching scheme for faster calculations. The results were validated with the Particle Image Velocimetry (PIV). The results show that the displacement distribution deviates from commonly assumed linearity. Moreover, the observed deformation mechanisms analysis suggest that the shear modulus G commonly determined through TS tests can be considerably overestimated.
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Optical Spectroscopic Studies of Tetrahydrofuran Fragmentation Induced by Collisions with Dihydrogen Cations
- Tomasz Wąsowicz
- Bogusław Pranszke
Collisions of dihydrogen cations with tetrahydrofuran molecules have been studied. Luminescence spectra and the emission functions of the excited products at projectile energies ranging from 8 to 1000 eV have been measured using collision-induced emission spectroscopy. The recorded spectra are dominated by the atomic lines of the hydrogen Balmer series, whose intensities decrease more quickly than derived by the quantum-theoretical principle. The spectra also exhibit weak molecular bands of vibrationally and rotationally excited diatomic CH fragments created in the A2D and B2S ectronic states. The collisional processes are identified and compared with the latest results on cation-induced fragmentation of tetrahydrofuran.
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Optical-Fiber Microsphere-Based Temperature Sensors with ZnO ALD Coating—Comparative Study
- Paulina Listewnik
- Mikhael Bechelany
- Paweł Wierzba
- Małgorzata Szczerska
This study presents the microsphere-based fiber-optic sensor with the ZnO Atomic Layer Deposition coating thickness of 100 nm and 200 nm for temperature measurements. Metrological properties of the sensor were investigated over the temperature range from 100 °C to 300 °C, with a 10 °C step. The interferometric signal was used to monitor the integrity of the microsphere and its attachment to the connecting fiber. For the sensor with a 100 nm coating, a spectrum shift of the reflected signal and the optical power of the reflected signal were used to measure temperature, while only the optical power of the reflected signal was used in the sensor with a 200 nm coating. The R2 coefficient of the discussed sensors indicates a linear fit of over 0.99 to the obtained data. The sensitivity of the sensors, investigated in this study, equals 103.5 nW/°C and 19 pm/°C or 11.4 nW/°C for ZnO thickness of 200 nm and 100 nm, respectively.
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OPTIMAL FARM SIZE AND EFFECTIVENESS OF AGRICULTURE IN THE EU: THE CASE OF WHEAT YIELDS
- Roman Skalicky
- Elżbieta Rogalska
- Michał Pietrzak
- Marek Zinecker
- Jana Meluzinova
The article concentrates on the relationship between the size of a farm and its efficiency in relation to wheat production in the European Union (EU). The issue is not new, however fundamental from the point of view of the agricultural policy, as the appropriate shape of the agrarian structure affects the economic rationality in agriculture and significantly improves the productivity. We analysed data for the period between 2004 to 2016 while using the Farm Accountancy Data Network. The fixed effects model was used to identify the explanatory variables for farm size and wheat yields. We calculate the yields per hectare as the ratio of the sum of input costs per hectare to the cost of producing a unit of yield per hectare. Using the 1st derivative, we then estimate the marginal cost of the inputs for each of the farm size categories. Our main conclusion is that with the growing size of a farm, there is a continuous increase in yields of wheat per hectare. This result is achieved by increasing the specific crop costs, a significant part of which are fertilizers and crop protection products, both with respect to the cultivated area and the production achieved. When evaluating the efficiency of production, the optimal size of the economic unit (according to the FADN categorization) is 5. Up to the size category 5, there is an increase in production with respect to the monetary value of production inputs. In the case of larger farms, the ratio is declining.
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Optimal Rotating Receiver Angles Estimation for Multicoil Dynamic Wireless Power Transfer
- Bohdan Pakhaliuk
- Viktor Shevchenko
- Jan Mućko
- Oleksandr Husev
- Mykola Lukianov
- Piotr Kołodziejek
- Natalia Strzelecka
- Ryszard Strzelecki
This study proposed an approach to dynamic wireless charging that uses a rotating receiver coil. Our simulation study focused on the verification of a novel way of increasing the coupling coefficient and power transfer stability by following the flux of the transmitting coils. To obtain the highest possible coupling by means of the FEM analysis, we studied the optimization of the trajectory of the angular velocity of the rotating receiver. The coupling coefficient trajectories that were obtained were simulated by means of the state space model with three transmitters. Our comprehensive analysis showed that the proposed approach of wireless power transmission enabled a 40% increase in the usage of track space
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Optimisation and field assessment of poroelastic wearing course bond quality
- Piotr Jaskuła
- Dawid Ryś
- Cezary Szydłowski
- Marcin Stienss
- Łukasz Mejłun
- Mariusz Jaczewski
- Grzegorz Ronowski
Compared to typical asphalt mixtures, poroelastic mixtures are characterised by high porosity and high flexibility, which are desirable for traffic noise reduction. However, the same properties increase the risk of debonding from the lower layer, which is a significant source of premature damage. The study investigates which of the factors – tack coat agent, type and texture of the lower layer – have the greatest impact on interlayer bonding quality. From 27 variants of interface bond techniques investigated in laboratory, 8 were selected and constructed on two full-scale test sections. Monotonic direct shear loading and cyclic direct shear loading tests with normal force were used for this purpose. The tests indicated that softer bitumen used for the tack coat and the milled texture of the lower layer improves bond quality. However the appropriate laying compaction has the major influence. Poroelastic mixtures are much more sensitive to technological imperfections than standard asphalt mixtures.
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Optimization of carbamazepine photodegradation on defective TiO2-based magnetic photocatalyst
- Szymon Dudziak
- Zuzanna Bielan
- Paweł Kubica
- Anna Zielińska-Jurek
In this work, carbamazepine (CBZ) degradation over defective Fe3O4@SiO2/d-TiO2/Pt photocatalyst was studied. Within the titania structure, Ti vacancies and Pt nanoparticles were introduced to enhance the photocatalyst’s light absorption and influence charge carriers’ mobility. For the carbamazepine degradation, process parameters, e.g., temperature, flux intensity, photocatalyst loading, aeration, pH, and addition of H2O2, were optimized for 4 or 5 different levels, with the quadratic model including 2-factor interactions determined to analyze the effect of these parameters. Carbamazepine presence and by-product formation were monitored using the HPLC-DAD system together with additional HPLC-TOFMS analysis for further identification of created compounds. Acridine was selected as an additional factor, indicating differences in the performed process of photolysis and photocatalytic CBZ degradation. Pure TiO2 exhibited the highest efficiency of CBZ degradation under alkaline conditions, while the performed optimization shows that a combination of H+ and H2O2 addition is crucial to achieve high CBZ removal and its mineralization in the presence of Fe3O4@SiO2/d-TiO2/Pt photocatalyst. The obtained results were discussed concerning photocatalyst structure, generation of reactive oxygen species inside H+/H2O2/photocatalyst system, and the possible effect of introduced Ti vacancies. In terms of reusability, the performance of Fe3O4@SiO2/d-TiO2/Pt photocatalyst was stable after 8 subsequent cycles of carbamazepine degradation.