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Charakterystyka procesu deamonifikacji oraz rozwój technologii usuwania azotu w oparciu o ten proces
- Dominika Grubba
- Hussein Al Hazimi
- Joanna Majtacz
- Jacek Mąkinia
2019
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Charakterystyka procesu utleniania stopów cyrkonu i jego wpływu na stan warstwy wierzchniej oraz desorpcję wodoru
- Bartłomiej Trybuś
2019 Pełny tekst
Zjawiska degradacji tlenowej i wodorowej stopów cyrkonu mają istotne znaczenie dla modelowania mechanizmów utraty spójności koszulek paliwowych w warunkach katastrof nuklearnych, szczególnie typu LOCA. Celem naukowym pracy było poznanie i analiza zachowania utlenionych, komercyjnych stopów cyrkonu, wpływu wodoru na utlenione stopy oraz przedstawienie fizycznych źródeł i matematycznych zależności pomiędzy tymi zjawiskami. Wyniki badań kinetyki utleniania w temperaturze poniżej punktu przemiany fazowej tlenku wykazały, że stałe szybkości utleniania są dla długich czasów 15 i 48 h zgodne z parabolicznym równaniem kinetycznym, natomiast są one niższe w przypadku czasów krótkich, 0,5 i 2 h. Badania erozji wodorowej ujawniły najniższy przyrost zawartości wodoru w stopie przy najdłuższym czasie jego utleniania potwierdzając tezę, iż warstwa tlenkowa istotnie spowalnia absorpcję i dyfuzję wodoru do wnętrza stopu. Podczas awarii może dojść do gwałtownego przegrzania elementów paliwowych prowadzących do przemian fazowych oraz utraty stabilności wymiarowej. Do celów zbadania procesów zachodzących w takich warunkach użyto, nie stosowanej jak dotąd, nieniszczącej metody tomografii komputerowej. Wyniki badań warstwy tlenkowej tworzącej się w temperaturze powyżej punktu przemiany fazowej ujawniły wpływ umiejscowienia warstwy tlenkowej na koszulce cyrkonowej na kinetykę utleniania, pojawienie się efektu korozji guzowatej, powstanie odkształceń na powierzchni stopu a także pęknięć na granicy tlenek - podłoże w pobliżu tych odkształceń.
Charakterystyka produktów utleniania fosfolipidów oraz określenie ich wybranych aktywności biologicznych w komórkach HT29 jako modelu ludzkiego przewodu pokarmowego
- Karol Parchem
2019
Wyniki licznych badań epidemiologicznych wskazują, że rodzaj, ilość oraz jakość dostarczanych wraz z pożywieniem lipidów może przyczyniać się do ograniczenia bądź rozwoju chorób dietozależnych, takich jak otyłość, cukrzyca typu 2, miażdżyca czy nadciśnienie tętnicze. Rosnące zainteresowanie określeniem wpływu lipidów dostarczanych z pożywieniem na funkcjonowanie ludzkiego organizmu wymaga przeprowadzenia licznych badań, zarówno pod kontem oznaczenia ich składu w próbkach żywności, jak i określenia ich aktywności biologicznej. Lipidami wykazującymi szczególną aktywność biologiczną, a tym samym będącymi w centrum badań lipidomicznych są fosfolipidy, a także produkty ich utlenienia. Celem niniejszej pracy doktorskiej była charakterystyka produktów enzymatycznego i termicznego utlenienia frakcji fosfolipidowej wyizolowanej z żółtka jaja kurzego, które zostało wybrane jako modelowe źródło fosfolipidów dostarczanych do organizmu z pożywieniem. W kolejnym etapie podjęto próbę określenia wpływu utlenienia fosfolipidów na kinetykę ich hydrolizy katalizowanej w wyniku aktywności trzustkowej fosfolipazy A2. Ponadto sprawdzono wpływ obecności utlenionych fosfolipidów na szybkość trawienia innych związków lipidowych, takich jak triacyloglicerole. Ostatnim celem prowadzonych badań było określenie cytotoksyczności i genotoksyczności mieszanin składających się z soli żółciowych oraz natywnych lub utlenionych fosfolipidów przed i po procesie trawienia jelitowego w warunkach in vitro. W wyniku prowadzonych prac badawczych zaproponowano metodę analizy utlenionych fosfolipidów opartą na technice dwuwymiarowej chromatografii cieczowej w trybie off-line sprzężonej z detektorem z matrycą diodową, detektorem naładowanego aerozolu oraz spektrometrem mas. Opracowana metoda została następnie wykorzystana podczas profilowania oraz identyfikacji produktów enzymatycznego i termicznego utlenienia frakcji fosfolipidowej, a także badania kinetyki tych reakcji. Utlenienie fosfolipidów przyczyniło się od zmniejszenia szybkości reakcji ich hydrolizy w wyniku aktywności fosfolipazy A2. Natomiast z drugiej strony obecność utlenionych fosfolipidów na powierzchni trawionych kropli lipidowych prowadziła prawdopodobnie do przyspieszenia reakcji hydrolizy triacylogliceroli w wyniku aktywności lipazy trzustkowej. Zarówno utlenienie, jak i hydroliza fosfolipidów w znaczący sposób wpływały na ich aktywność biologiczną.
Charge density wave and large nonsaturating magnetoresistance in YNiC2 and LuNiC2
- Kamil Kolincio
- Marta Roman
- Tomasz Klimczuk
2019 Pełny tekst PHYSICAL REVIEW B
We report a study of physical properties of two quasi-low-dimensional metals YNiC2 and LuNiC2 including the investigation of transport, magnetotransport, galvanomagnetic, and specific heat properties. In YNiC2 we reveal two subsequent transitions associated with the formation of weakly coupled charge density wave at TCDW=318K and its locking in with the lattice at T1=275K. These characteristic temperatures follow the previously proposed linear scaling with the unit cell volume, demonstrating its validity extended beyond the lanthanide-based RNiC2. We also find that, in the absence of magnetic ordering able to interrupt the development of charge density wave, the Fermi surface nesting leads to opening of small pockets, containing high-mobility carriers. This effect gives rise to substantial enhancement of magnetoresistance, reaching 470% for YNiC2 and 50% for LuNiC2 at T=1.9K and B=9T.
Charge Transfer, Complexes Formation and Furan Fragmentation Induced by Collisions with Low-Energy Helium Cations
- Tomasz Wąsowicz
- Marta Łabuda
- Boguslaw Pranszke
2019 Pełny tekst INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
The present work focuses on unraveling the collisional processes leading to the fragmentation of the gas-phase furan molecules under the He+ and He2+ cations impact in the energy range 5–2000 eV. The presence of diﬀerent mechanisms was identiﬁed by the analysis of the optical fragmentation spectra measured using the collision-induced emission spectroscopy (CIES) in conjunction with the ab initio calculations. The measurements of the fragmentation spectra of furan were performed at the diﬀerent kinetic energies of both cations. In consequence, several excited products were identiﬁed by their luminescence. Among them, the emission of helium atoms excited to the 1s4d1D2,3D1,2,3 states was recorded. The structure of the furan molecule lacks an He atom. Therefore, observation of its emission lines is spectroscopic evidence of an impact reaction occurring via relocation of the electronic charge between interacting entities. Moreover, the recorded spectra revealed signiﬁcant variations of relative band intensities of the products along with the change of the projectile charge and its velocity. In particular, at lower velocities of He+, the relative cross-sections of dissociation products have prominent resonance-like maxima. In order to elucidate the experimental results, the calculations have been performed by using a high level of quantum chemistry methods. The calculations showed that in both impact systems two collisional processes preceded fragmentation. The ﬁrst one is an electron transfer from furan molecules to cations that leads to the neutralization and further excitation of the cations. The second mechanism starts from the formation of the He−C4H4O+/2+ temporary clusters before decomposition, and it is responsible for the appearance of the narrow resonances in the relative cross-section curves
Chemical and Mechanical Properties of 70-Year-Old Concrete
- Andrzej Ambroziak
- Elżbieta Haustein
- Jarosław Kondrat
2019 Pełny tekst JOURNAL OF MATERIALS IN CIVIL ENGINEERING
The aim of this research is to determine the durability and strength of concrete continuous footing based on the chosen mechanical, physical, and chemical properties of the concrete. The presented investigations constitute some opinions from experts on the bearing capacity of concrete continuous footing and the possibilities of carrying additional loads and extended working life. The cylindrical specimens were taken from continuous footing by a concrete core bore hole diamond drill machine. The properties of old concrete are compared with present and old standard requirements and guidelines. Large dispersions of the cylindrical compressive strength (6.9–29.3 MPa), density (1,750–2,100 kg/m3), and water absorption (5%–14%) were observed. A short literature survey concerning old concrete properties is also given.
Chemical Aspects of Biological Activity of Isothiocyanates and Indoles, the Products of Glucosinolate Decomposition
- Dominik Kołodziejski
- Izabela Koss-Mikołajczyk
- Ahmad Yaman Abdin
- Jacob Claus
- Agnieszka Bartoszek-Pączkowska
2019 Pełny tekst CURRENT PHARMACEUTICAL DESIGN
There is growing evidence that cancer chemoprevention employing natural, bioactive compounds may halt or at least slow down the different stages of carcinogenesis. A particularly advantageous effect is attributed to derivatives of sulfur-organic phytochemicals, such as glucosinolates (GLs) synthesized mainly in Brassicaceae plant family. GLs are hydrolysed enzymatically to bioactive isothiocyanates (ITC) and indoles, which exhibit strong anti-inflammatory and anti-carcinogenic activity. Highly bioavailable electrophilic ITC are of particular interest, as they can react with nucleophilic groups of important biomolecules to form dithiocarbamates, thiocarbamates and thioureas. These modifications seem responsible for the chemopreventive activity, but also for genotoxicity and mutagenicity. It was documented that ITC can permanently bind to important biomolecules such as glutathione, cytoskeleton proteins, transcription factors NF-κB and Nrf2, thiol-disulfide oxidoreductases, proteasome proteins or heat shock proteins. Furthermore, ITC may also affect epigenetic regulation of gene expression, e.g. by inhibition of histone deacetylases. Some other derivatives of glucosinolates, especially indoles, are able to form covalent bonds with nucleobases in DNA, which may result in genotoxicity and mutagenicity. This article summarizes the current state of knowledge about glucosinolates and their degradation products in terms of possible interactions with reactive groups of cellular molecules.
Chemical structures, rheological and physical properties of biopolyols prepared via solvothermal liquefaction of Enteromorpha and Zostera marina biomass
- Paulina Kosmela
- Kamila Gosz
- Paweł Kazimierski
- Aleksander Hejna
- Józef Haponiuk
- Łukasz Piszczyk
2019 Pełny tekst CELLULOSE
In this work, liquefied biomass from the Baltic Sea was used for the preparation of rigid polyurethane (PUR) foams. The biomass contained 10 wt% of Enteromorpha macroalgae and 90 wt% of Zostera marina seagrass characterized by a high content of cellulose. The influence of time, temperature and the type of solvent on the efficiency of the liquefaction process and properties of biopolyols was determined. Obtained materials were analyzed in terms of chemical structure, rheological properties, thermal stability and basic physical and mechanical properties. It was found that optimal parameters for liquefaction of used biomass were: temperature of 150 °C, reaction time of 6 h and a solvent mixture containing glycerol and poly(ethylene glycol) in ratio of 50:50 (biopolyol 50G50P_150). Under these conditions, 78 wt% of biomass was liquefied and resulting biopolyol was characterized by a hydroxyl number of 650 mg KOH/g. Depending on the used solvent mixture and the liquefaction temperature, biopolyols showed the character of Newtonian or non-Newtonian liquids. Rigid PUR foams were obtained by substitution of petrochemical polyol with 10, 20 and 30 wt% of biopolyol. It was found that the addition of biopolyol to foams’ formulations did not cause significant changes in their chemical structure, while mechanical strength and thermal stability were enhanced. The presented study confirms that biomass from the Baltic Sea can be used for the synthesis of biopolyols and rigid polyurethane foams.
Chemical variability of Rhododendron tomentosum (Ledum palustre) essential oils and their pro-apoptotic effect on lymphocytes and rheumatoid arthritis synoviocytes
- Anna Jesionek
- Adam Kokotkiewicz
- Anna Mikosik-Roczynska
- Klaudia Ciesielska-Figlon
- Piotr Luczkiewicz
- Adam Bucinski
- Agnieszka Daca
- Jacek M. Witkowski
- Ewa Bryl
- Bożena Zabiegała
- Maria Luczkiewicz
2019 Pełny tekst FITOTERAPIA
Rhododendron tomentosum (Ledum palustre) is an aromatic plant traditionally used for alleviating rheumatic complaints which makes it a potential candidate for a natural drug in rheumatoid arthritis (RA) treatment. However, the effects of plants’ volatiles on apoptosis of synovial fibroblasts and infiltrating leucocytes of RA synovia, have not been reported. Volatile fraction of R. tomentosum is chemically variable and chemotypes of the plants need to be defined if the oil is to be used for therapeutic purposes. In the presented work, cluster analysis of literature data enabled to define 10 chemotypes of the plant. The volatile fractions of known composition were then tested for bioactivity using a RA-specific in vitro models. Essential oils of two wild types (γ-terpineol and palustrol/ledol type) and one in vitro chemotype (ledene oxide type) were obtained by hydrodistillation and their bioactivity was tested in two in vitro models: I - peripheral blood lymphocytes of healthy volunteers and II - synoviocytes and immune cells isolated from synovia of RA patients. The influence of oils on blood lymphocytes’ proliferation and apoptosis rates of synovia-derived cells was determined by flow cytometry. Dose-dependent inhibitory effect of the serial dilutions of R. tomentosum oils on proliferation rates of blood lymphocytes was found. At 1:400 dilutions, all the tested oils increased the number of necrotic cells in synovial fibroblasts from RA synovia. Additionally, increased proportions of late apoptotic cells were observed in leucocyte populations subjected to oils at 1:400 dilution.
Chemometrics and Statistics | Multicriteria Decision Making
- Marta Bystrzanowska
- Marek Tobiszewski
2019
This contribution describes the application of Multicriteria Decision Making tools in analytical chemistry. The general scheme of MCDM is presented to show its general steps. The most frequently applied in analytical sciences MCDM techniques – AHP, ELECTRE, PROMETHEE and TOPSIS – are briefly described and their advantages and disadvantages are discussed. The applications in analytical chemistry are selection of an appropriate analytical procedure and optimization of analytical processes. MCDM techniques are also applied to select analytical reagents according to their environmental impact, human health and safety issues – solvents and derivatization agents are assessed in this way.
Chitosan and polyvinyl alcohol nanocomposites with cellulose nanofibers from ginger rhizomes and its antimicrobial activities
- Joby Jacob
- Gregary Peter
- Sabu Thomas
- Józef Haponiuk
- Sreeraj Gopi
2019 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
The inhibitory effect of 5% GNF bionanocomposites against Bacillus cereus, Escherichia coli, Staphylococcus aureus and Salmonella typhimurium indicated good antibacterial activity of the nanocomposites due to the addition of GNF in the biopolymer matrices. The use of GNF will help to increase the economic values of agricultural waste and the characteristic properties of GNF derived bionanocomposites could be possibly used in medical and packaging areas.
Chromatgrafia cieczowa. Teoria i praktyka
- Waldemar Wardencki
- Zygfryd Witkiewicz
- Irena Malinowska
2019
Książka zawiera całokształt wiedzy dotyczącej chromatografii ciecvzowej - kolumnowej i cienkowarstwowej. Opisane zostały wszystkie techniki chromatografii cieczowej, zarówno w zakresie teorii chromatografii, jak i praktycznych zastosowań.
Ciecze jonowe jako medium sorpcyjne w mikroekstrakcji do pojedynczej kropli Cz. I. Podstawy teoretyczne zagadnienia
- Karolina Konieczna
- Łukasz Marcinkowski
- Adam Kloskowski
- Jacek Namieśnik
2019 Analityka: Nauka i Praktyka
Technika mikroekstrakcji do pojedynczej kropli stanowi sztandarowy przykład rozwiązania technicznego spełniającego wymogi stawiane przez ideę zielonej chemii analitycznej.
Ciecze jonowe jako medium sorpcyjne w mikroekstrakcji do pojedynczej kropli. Cz.II. Praktyka analityczna
- Karolina Konieczna
- Łukasz Marcinkowski
- Adam Kloskowski
- Jacek Namieśnik
2019 Analityka: Nauka i Praktyka
Pomimo rosnącego zainteresowania metodami analitycznymi opartymi na użyciu cieczy jonowych ich sprzężenie wraz z techniką mikroekstrakcji do pojedynczej kropli nie osiągnęło zadowalającej popularności oraz akceptacji ze strony środowiska naukowego.
City walk: a didactic innovative experiment in architectural education
- Justyna Borucka
2019 Pełny tekst World Transactions on Engineering and Technology Education
Walking is an activity that involves studying physical space and requires careful observation to be immersed in the surrounding reality. City walks are popular ways of encountering an urban space, spatial relation, its history, and recognising the problems and needs of space users, as well as future development of the city. City walks also may be educationally p owerful: the exploration of certain city spaces and their associated narratives. The aim of this article is to present a city walk as an experimental tool in architectural education, in particular as a method of critical engagement with city problems and the needs of its users. City walks are an experiment, a method of studying spatial relations to raise the awareness of future architects and urban planners. The question arising from the researchconcerns the role that urban walks can play in creating the spatial and critical involvement of future architects and urban planners. The study was based on city walk experiments conducted by the Faculty of Architecture at Gdańsk University of Technology (GUT), Gdańsk, Poland, in collaboration with a number of partner.
CIVILIZING THE PUBLIC PARTICIPATION PRACTICE IN POST-TRANSITION COUNTRIES
- Piotr Lorens
2019 Pełny tekst IOP Conference Series: Materials Science and Engineering
The phenomenon of public participation is not so new to both planning theory and practice. In fact, involving local community in the decision-making process regarding local urban development directions is widely discussed and a number of various forms of these are being introduced. This paper deals with a number of
Clarke duality for Hamiltonian systems with nonstandard growth
- S Acinas
- Jakub Maksymiuk
- F Mazzone
2019 Pełny tekst NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS
We consider the existence of periodic solutions to Hamiltonian systems with growth conditions involving G-function. We introduce the notion of symplectic G-function and provide relation for the growth of Hamiltonian in terms of certain constant CG associated to symplectic G-function G. We discuss an optimality of this constant for some special cases. We also provide applications to the Φ-laplacian type systems.
Classification of objects in the LIDAR point clouds using Deep Neural Networks based on the PointNet model
- Zdzisław Kowalczuk
- Karol Szymański
2019 Pełny tekst IFAC-PapersOnLine
This work attempts to meet the challenges associated with the classification of LIDAR point clouds by means of deep learning. In addition to achieving high accuracy, the designed system should allow the classification of point clouds covering an area of several dozen square kilometers within a reasonable time interval. Therefore, it must be characterized by fast processing and efficient use of memory. Thus, the most popular approaches to the point cloud classification using neural networks are discussed. At the same time, their shortcomings are indicated. A developed model based on the PointNet architecture is presented and the way of preparing data for classification is shown. The model is tested on a cloud coming from the 3D Semantic Labeling competition, achieving a good result, confirmed by the high quality of the system, i.e. a high rate of categorization of objects.
Classification of Urban Regeneration Participants as a Basis for Identification of Construction Investment's Risk Sources
- Magdalena Apollo
2019 Pełny tekst IOP Conference Series: Materials Science and Engineering
On the basis of the conducted research it can be concluded that the majority of the existing urban regeneration problems are revealed by the lack of an in-depth analysis of sources and risk factors. For the above reasons, the subject of this study is classification of urban regeneration's participants as a basis for identification of construction investment's risk sources. The research methodology is based on an in-depth analysis of the available documentation of four urban regeneration projects implemented in Gdańsk, which was confronted with the provisions of the Regeneration Act. The conducted analysis allowed to clearly classify the participants of urban regeneration process, also indicating its direct and indirect beneficiaries. As a consequence, the elaboration defines the responsibility of participants in the investment process, and at the same time allows to divide the risk between individual entities implementing activities covered by the intervention area. The observations described in the article also concern shortcomings in the documentation including, among others, lack of the definition of the required experience of design units depending on the nature of the construction works being carried out.
Clearing directed subgraphs by mobile agents
- Dariusz Dereniowski
- Andrzej Lingas
- Dorota Osula
- Mia Persson
- Paweł Żyliński
2019 Pełny tekst JOURNAL OF COMPUTER AND SYSTEM SCIENCES
We study several problems of clearing subgraphs by mobile agents in digraphs. The agents can move only along directed walks of a digraph and, depending on the variant, their initial positions may be pre-specified. In general, for a given subset S of vertices of a digraph D and a positive integer k, the objective is to determine whether there is a subgraph H=(V,A) of D such that (a) S is a subset of V, (b) H is the union of k directed walks in D, and (c) the underlying graph of H includes a Steiner tree for S in D. Since a directed walk is a not necessarily a simple directed path, the problem is actually on covering with paths. We provide several results on the polynomial time tractability, hardness, and parameterized complexity of the problem. Our main fixed-parameter algorithm is randomized.