Search
Filters
total: 1054
filtered: 936
Search results for: polyurethanes foams
-
Experimental tests and numerical simulations of full scale composite sandwich segment of a foot- and cycle- bridge
PublicationIn the paper experimental tests and numerical simulations of a full cross-section segment of ultimately designed foot-and cycle-bridge are presented. The experimental tests were conducted on element with length reduced to 3 m and unchanged (target) cross-section dimensions. The external skin of structure is GFRP laminate while internal core is PET foam. Several quasi-static tests were performed using hydraulic cylinder to generate...
-
Failure characterisation of sandwich beams using integrated acoustic emission and digital image correlation techniques
PublicationThe paper presents the experimental study of the failure behaviour of sandwich beams subjected to bending. The samples examined are sandwich beams made of polyethylene terephthalate foam core and glass fibre-reinforced polymer laminate face sheets. In a series of experiments, it has been proposed to integrate diagnostic techniques with acoustic emission and digital image correlation to accurately track the cracking process on the...
-
Rola przekształceń styku lądu i wody w procesach rewitalizacji
PublicationArtykuł poświęcony jest zweryfikowaniu roli, jaką pełnią przekształcenia granic miedzy lądem i wodą w procesach rewitalizacji. Analizując szereg tego typu działań, w szczególności dotyczących transformacji obszarów poprzemysłowych, można zauważyć, że w ostatnim czasie charakterystyczne dla nich stają się modyfikacje planów obszarów wodnych i form ich granic. Jak okazuje się, działania takie mają nie tylko znaczenie kompozycyjne...
-
From polymer waste to potential main industrial products: Actual state of recycling and recovering
Publicationlastics have become widely used materials in everyday life due to their special properties such as durability, easy processing, light-weight and low-cost of production. However, because of their stable and non-biodegradable nature, postconsumer plastics become an issue to the environment. The growing amounts of waste are generated, as plastic products are commonly used only once before disposal. The alternatives of practical techniques...
-
Microcrystalline Cellulose Management in the Production of Poly(ether-urethane)s- Structure, Morphology, and Thermal Characteristic
PublicationIn response to the demand of polymer industry for reducing the use of synthetic chemicals, eco-friendly materials are investigated. In the presented study, bio-based poly(ether-urethane)s were prepared by using microcrystalline cellulose (MCC) and polyether polyol and 1,3-propanediol derived from corn sugar. A step towards sustainability was taken by incorporating bio-based compounds and cellulose, consequently, bio-waste are utilized...
-
Prediction of ship resistance with the use of Full-scale CFD simulations
PublicationIn recent years, the IMO has introduced new regulations to reduce the negative impact of ships on the natural environment. A particularly important step forcing technological innovations is the increasing requirement of ship energy efficiency. It is expressed by the Energy Efficiency Design Index (EEDI). Another important step towards green shipping is rising the required quality of fuel used for propulsion, so called Tier limits....
-
The potential of urban agriculture in the revitalisation of a metropolis
PublicationIn Poland, the topic addressing urban areas of agricultural production and gardening activity is still viewed in two main blocks: 1) a shift of the urbanized zone’s boundaries, causing dispersion of suburban buildings as well as creates conflict zone between the residential area and the production and post-production zones; 2) a socially contentious issue of restructuring the inner-city complexes of former employee allotments....
-
KOMPOZYTOWY MOST PIESZO - ROWEROWY
PublicationPaper presents the composite foot and cycle bridge developed in FOBRIDGE grant cofinanced by The National Centre for Research and Development and realized by consortium of Gdansk University of Technology (leader), Military University of Technology in Warsaw and ROMA Sp. z o.o. in Toruń. The purpose of the grant was to design a shell type single span foot and cycle bridge made of composite materials, with the assumption of manufacturing...
-
Modele budowy wartości dla klienta - charakterystyka i rozwinięcie
PublicationRozwój form realizacji biznesu umożliwił zbadanie nowych obiektów związanych z generowaniem wartości dla klienta i przedsiębiorstwa. W pracy scharakteryzowano logiki tworzenia wartości będące podstawą modeli łańcucha wartości, sklepu wartości, sieci wartości oraz chmury wartości. Zaproponowano także wprowadzenie nowego składnika do struktury tych modeli w postaci węzła wartości.
-
DYNAMICZNA APLIKACJA INTERNETOWA SYMULACJI OBWODOWEJ MASZYNY INDUKCYJNEJ. UJĘCIE OBIEKTOWE
PublicationArtykuł dotyczy zastosowania dynamicznej aplikacji internetowa do symulacji obwodowej silnika indukcyjnego trójfazowego, wykorzystującej interfejs przeglądarki WWW. Model obwodowy silnika sformułowano w układzie osiach naturalnych i ujęciu metody energetycznej Lagrange’a. Implementację modelu maszyny w aplikacji internetowej wykonano w projekcie typu Web Forms, który jest elementem środowiska Microsoft Visual Studio. Kod programu...
-
Analysis of arsenic species in environmental samples
PublicationMany analytical methods for determining arsenic in various forms in environmental samples have been developed in recent years. The main objective of this review article is the presentation and comparison of the three principal techniques for the determination arsenic compounds, namely: hydride generation (HG), voltammetry and chromatography (liquid chromatography including high-performance liquid chromatography (HPLC), and gas...
-
Controlling computer by lip gestures employing neural network
PublicationResults of experiments regarding lip gesture recognition with an artificial neural network are discussed. The neural network module forms the core element of a multimodal human-computer interface called LipMouse. This solution allows a user to work on a computer using lip movements and gestures. A user face is detected in a video stream from a standard web camera using a cascade of boosted classifiers working with Haar-like features....
-
Fabrication, Microstructure and High Temperature Corrosion Resistance of Porous Alloys for Solid Oxide Fuel Cells
PublicationPorous alloys find use in modern Solid Oxide Fuel Cells as the supporting structures. As they are exposed to high temperatures (> 500°C) an oxide scale forms on their surface due to high temperature corrosion phenomena. Since the ratio between the surface area and volume is much higher than for planar samples, formation of the oxide can lead to a breakaway oxidation after relatively short times. Therefore corrosion properties of...
-
Bis(ammonium) Zoledronate Dihydrate
PublicationNeutralization of 2-(1-imidazole)-1-hydroxyl-1,1`-ethylidenediphosphonic acid (zoledronic acid) by an excess of ammonia yielded bis(ammonium) zoledronate dihydrate, {C5H8N2O7P2 2−, 2(H4N+), 2(H2O)}. The product is readily soluble in water and forms monocrystals for which the X-ray structural analysis was carried out. The zoledronic anion is of double negative charge due to deprotonation of three P–OH groups and protonation of the...
-
Comparison of the coordination geometries of Zn(II) and Cd(II) ions in complexes with water, methanol and bulky aryloxysilanethiolate ligands
PublicationZinc and cadmium complexes containing silanethiolate anions and methanol or water were synthesized and characterized by X-ray diffraction, FT-IR and NMR spectroscopy, and DFT calculations. Contrary to zinc, the cadmium ion utilizes very weak donors to complete its coordination sphere; it forms contacts to phenyl rings of the silanethiolate ligand. Two zinc analogs of the general formula [Zn{SSi(OAr)3}2(L)2] where L = CH3OH (2)...
-
Is This Distance Teaching Planning That Bad?
PublicationIn spring 2020, university courses were moved into the virtual space due to the Covid-19 lockdown. In this paper, we use experience from courses at Gdańsk University of Technology and ETH Zurich to identify core problems in distance teaching planning and to discuss what to do and what not to do in teaching planning after the pandemic. We conclude that we will not return to the state of (teaching) affairs that we had previously....
-
On thermal stability of piezo-flexomagnetic microbeams considering different temperature distributions
PublicationBy 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...
-
Polysaccharide-based electroconductive hydrogels: Structure, properties and biomedical applications
PublicationArchitecting an appropriate platform for biomedical applications requires setting a balance between simplicity and complexity. Polysaccharides (PSAs) play essential roles in our life in food resources, structural materials, and energy storage capacitors. Moreover, the diversity and abundance of PSAs have made them an indispensable part of food ingredients and cosmetics. PSA-based hydrogels have been extensively reviewed in biomedical...
-
The Prospects of Retail Payment Developments in the Metaverse
PublicationIn the age of technological development, rapid technological progress, and the metaverse development in which humans interact with each other and with the environment using virtual real-world metaphors, payment systems may also need to be re-considered. The study aims to find an answer to the question of what should be retail payments in the metaverse and to begin interdisciplinary discussions about...
-
Ergonomic Aspects of Development of Architecture in the Context of Sanitary and Hygiene Safety
PublicationAbstract Ergonomics answers the need of safe development of space by creating spatial forms which help to implement the safety procedures and limit the threats involved both in ordinary use of the spaces and in case of unforeseen events. Using the knowledge of ergonomics and architecture on the basis of defining the routes of germ transmission, allows to limit the spread of those organisms. Ergonomics of developing architectural...
-
The role of analytical chemistry in the study of the Anthropocene
PublicationThe term “Anthropocene” refers to not yet formalized epoch of geologic time during which geologic processes have been dominated by the human impact. This impact takes on many forms. Biological, physical and chemical changes to the Earth System caused by anthropogenic activity are recorded in natural archives either as new fossil assemblages (neobiota), anthropogenic deposits or a wide variety of pollutants emitted to the environment....
-
Digital Government and Administrative Burden Reduction
PublicationAdministrative burden represents the costs to businesses, citizens and the administration itself of complying with government regulations and procedures. The burden tends to increase with new forms of public governance that rely less on direct decisions and actions undertaken by traditional government bureaucracies, and more on government creating and regulating the environment for other, non-state actors to jointly address public...
-
Synthesis and biological evaluation of N-acylated tyramine sulfamates containing C-F bonds as steroid sulfatase inhibitors
PublicationSteroid sulfatase (STS) is responsible for the hydrolysis of biologically inactive sulfated steroids into their active un-sulfated forms and promotes the growth of various hormone-dependent cancers (e.g., breast cancer). Therefore, the STS enzyme is a promising therapeutic target for the treatment of steroid-sensitive cancers. Herein, we report the synthesis and biological evaluation of sulfamate analogs as potential STS inhibitors...
-
Numerical simulations of overflow experiments on a model dike
PublicationDike failure due to overtopping is one of the important factors, which should be considered in the dike designing process. Although the overflow is characterized by the relatively low risk of occurrence, in many cases dikes are totally destroyed or seriously damaged. An interesting phenomenon occurring during overflow is the trapping of air in pores of the unsaturated soil material. As the infiltration progresses from all sides,...
-
Architektura latarni morskich wczoraj i dziś
PublicationLatarnie morskie jako znaki nawigacyjne są niezwykle interesującymi obiektami architektonicznymi. Smukłe formy wynikające z ich funkcji oraz specyficzna lokalizacja sprawiają, że są one charakterystycznymi punktami w krajobrazie nadmorskim. Identyfikują go wizualnie i stają się magnesem przyciągającym turystów. Latarnie morskie, jak wszystkie obiekty korzystające z rozwoju budownictwa i techniki zmieniały swoją formę, nie zmieniając...
-
Structural features responsible for control of the eukaryotic GlcN-6-P synthase activity
PublicationGlucosamine-6-phosphate (GlcN-6-P) synthase is responsible for catalysis of the first and practically irreversible step in hexosamine metabolism. As UDP-GlcNAc, the final product of the hexosamine path, constitutes one of the essential substrates for assembly of bacterial and fungal cell walls, the enzyme is an interesting target for antimicrobial therapy.The structure of E. coli enzyme, known since 2001, forms a dimer of two identical...
-
Typology and comparative analysis of black tents built in tradition of iranian tribes
PublicationThis study focused on the habits and way of life of nomads in the Iranian Highlands, but their homes, called Black Tents, were of the main interest. The research explored the construction of the Black Tents and the way of shaping the space in which family life takes place. It concerned the architectural forms of tents, structures and materials from which they are erected, as well as interior furnishings and objects that determine...
-
Empirical analysis of tree-based classification models for customer churn prediction
PublicationCustomer churn is a vital and reoccurring problem facing most business industries, particularly the telecommunications industry. Considering the fierce competition among telecommunications firms and the high expenses of attracting and gaining new subscribers, keeping existing loyal subscribers becomes crucial. Early prediction of disgruntled subscribers can assist telecommunications firms in identifying the reasons for churn and...
-
Reshaping of Coastlines as the Beginning of Urban Structures Changes in North Poland
PublicationThis article discusses the problem of strategies concerning the processes of re-shaping the Baltic Sea southern coastline applied recently in North Poland. The undertaken research is an attempt to identify the relationship between the modifications of coastline forms and the positive changes of urban structures. It can be seen that these modifications are needed because of the problems of existing shoreline erosion. It can be also...
-
Interactions of selected mono- and disaccharides with precipitated calcium carbonate particles
PublicationCalcium carbonate is a widespread compound in nature and it can be produced by living organisms in the biomineralization process. Calcite, aragonite and vaterite are anhydrous polymorphic forms of calcium carbonate, wherein the calcite is the most thermodynamically stable. Vaterite is the metastable crystalline phase, which can be a precursor of calcite and aragonite, because it can easily transformed by dissolution and re crystallization...
-
Experimental and numerical evaluation of mechanical behaviour of composite structural insulated panels
PublicationComposite structural insulated panels (CSIPs) are novel prefabricated elements for structural applications. Panels under consideration are made from glass-fibre reinforced magnesia cement boards as facesheets and expanded polystyrene foam (EPS) as a core. Quasi-static full-scale and model bending tests under monotonic loading were performed to recognize mechanical properties of CSIPs in flexure. In addition, tensile, compressive,...
-
Composite GFRP U-shaped footbridge
PublicationThe paper presents proposals for the use of glass fiber reinforced polymer composites for the construction of engineering objects, known and commonly used in the shipbuilding industry. An example of a pedestrian footbridge was used in this case, which, despite the considerable thickness of the structural material, was made using infusion technology in one production cycle. The designed and produced footbridge span is durable, dynamically...
-
Fundamental properties of solutions to fractional-order Maxwell's equations
PublicationIn this paper, fundamental properties of solutions to fractional-order (FO) Maxwell's equations are analysed. As a starting point, FO Maxwell's equations are introduced in both time and frequency domains. Then, we introduce and prove the fundamental properties of electromagnetic field in FO electromagnetics, i.e. energy conservation, uniqueness of solutions, and reciprocity. Furthermore, the algorithm of the plane wave simulation...
-
Dynamiczna aplikacja internetowa maszyny indukcyjnej w ujęciu obiektowym dla potrzeb symulacji obwodowej
PublicationTematem referatu jest dynamiczna aplikacja internetowa, która umożliwia symulację obwodową silnika indukcyjnego trójfazowego z wykorzystaniem interfejsu przeglądarki WWW. Model matematyczny silnika jest zdefiniowany w tzw. osiach naturalnych i sformułowany na podstawie metody energetycznej Lagrange’a. Do implementacji modelu maszyny w aplikacji internetowej wybrano projekt typu Web Forms, który jest składnikiem środowiska programistycznego...
-
Development of Local IDF-formula Using Controlled Random Search Method for Global Optimization
PublicationThe aim of the study is to present the effective and relatively simple empirical approach to rainfall Intensity-Duration-Frequency-formulas development, based on Controlled Random Search (CRS) for global optimization. The approach is mainly dedicated to the cases in which the commonly used IDF-relationships do not provide satisfactory fit between simulations and observations, and more complex formulas with higher number of parameters...
-
Cloud solutions as a platform for building advanced learning platform, that stimulate the real work environment for project managers
PublicationImproving skills of managers and executives require, that during the transfer of knowledge (in different ways: during studies, trainings, workshops and other forms of education) it is necessary to use tools and solutions that are (or will be) used in real world environments, where people being educated are working or will work. Cloud solutions allow educational entities (universities, training companies, trainers, etc.) to provide...
-
Development of trolleybus public transport in Gdynia as part of sustainable mobility strategy
PublicationIn many EU cities trolleybuses are experiencing a period of revitalization. New lines, new and modern trolley-buses, the use of auxiliary propulsion battery, eco-logical values and others, create great opportunities for that kind of public transport as an effective tool to shape transport policy in accordance with the principles of sustainable mobility. Gdynia is one of three cities in Poland with trolleybuses public transport...
-
Developing an Ontology from Set of Experience KnowledgeStructure
PublicationWhen referring to knowledge forms,collecting for all decision eventsin a knowledge-explicit way becomes a significant ask for any company. Set of experience knowledge structure can assis in accomplishing this purpose.However,after collecting,distributing and sharing that knowledge as adecisional DNA is even a more important advance.Distributing and sharing companies' decisional DNA through an efficient development of Ontologies...
-
Synthesis and electrochemical characteristics of novel dithiocarbamate polymers
PublicationNovel dithiocarbamate compounds have been obtained by reacting a linear poly(ethylenimine)polymer, MW 50,000, with CS2. The resulting anionic polymers contain, depending on the reaction conditions, up to two sulfur atoms per one nitrogen atom (approx. 40% w/w). The polymers are soluble in dimethylsulfoxide and insoluble in acetonitrile solutions. In both solvents they are electrochemically active, in the latter case as a cast film...
-
Electron impact iozization of CCl4 and SF6 embedded in superfluid helium droplets
PublicationElectron impact ionization of helium nano-droplets containing several 104 He atoms and doped with CCl4 or SF6 molecules is studied with high-mass resolution. The mass spectra show significant clustering of CCl4 molecules, less so for SF6 under our experimental conditions. Positive ion efficiency curves as a function of electron energy indicate complete immersion of the molecules inside the helium droplets in both cases. For CCl4...
-
Jumping Wave Characteristic during Low Plasticity Burnishing Process
PublicationDuring the low plasticity burnishing process of soft materials such as carbon steel with a hardness of up to 40 HRC (Rockwell grade) a raised structure of the material known as the Jumping Wave forms in front of the tool roll. This phenomenon significantly disturbs the burnishing process, but is very poorly described in the literature. This article presents studies of this phenomenon on the example of burnished 1.0562 steel. The...
-
Novel Cold Crucible Ultrasonic Atomization Powder Production Method for 3D Printing
Publication: A new powder production method has been developed to speed up the search for novel alloys for additive manufacturing. The technique involves an ultrasonically agitated cold crucible installed at the top of a 20 kHz ultrasonic sonotrode. The material is melted with an electric arc and undergoes pulverization with standing wave vibrations. Several different alloys in various forms, including noble and metallic glass alloys, were...
-
“Green” nature of the process of derivatization in analytical sample preparation
PublicationNowadays, the idea of Green Analytical Chemistry (GAC) is of high importance what impacts on the rapid growth in the sample preparation area with special emphasis on sample preparation simplification, miniaturization, and automation. Because the derivatization process is often an essential element of the analytical procedure, it should be important to focus on this issue from GAC perspective and conduct a series of experiments...
-
Performance of microbial fuel cells operated under anoxic conditions
PublicationNowadays, microbial fuel cells (MFC) stand up as a promising renewable energy source. Due to the ability of the MFC to oxidize a wide spectrum of substrates, wastewater seems to be one of the most interesting fuels. Unfortunately, wastewater could contain electron acceptors such as nitrate, which could interfere with the electrical performance of the MFC. In this work, the influence of oxidised nitrogen forms on the electricity...
-
Shape-Based Pose Estimation of Robotic Surgical Instruments
PublicationWe describe a detector of robotic instrument parts in image-guided surgery. The detector consists of a huge ensemble of scale-variant and pose-dedicated, rigid appearance templates. The templates, which are equipped with pose-related keypoints and segmentation masks, allow for explicit pose estimation and segmentation of multiple end-effectors as well as fine-grained non-maximum suppression. We train the templates by grouping examples...
-
PLANOWANIE BEZPIECZNYCH I „ZIELONYCH” SYSTEMÓW KOMUNIKACYJNYCH
PublicationIn order to achieve balanced forms of urban infrastructure, which ensure comfort, safety and spatial order, when designing new solutions it is necessary to adopt a multi-facet approach which will combine everything that the local residents need but will respond harmoniously to the existing cultural landscape. It is therefore necessary to work out complex undertakings for the sake of planning and developing urban space. Coherent...
-
Results of acoustic emission tests of corrosion protection degree of ship steel tanks covered by means of protective coatings (Phase I)
PublicationThis paper presents methods and results of the 1st series of tests of acoustic emission (AE) signals, aimed at assessing degree of corrosion protection of a tank made of hull structural steel, protected by means of a protective coating combined from polyurethane layer and concrete filler. The tests were carried outin compliance with a method specially elaborated for application to the work in question. In the method were used requirements...
-
WPŁYW KAUSTYKI NA AKUSTYKĘ GROT SZEPTÓW W PARKU OLIWSKIM W GDAŃSKU
PublicationW pracy omówiono kaustykę jako uporządkowaną formę rozmycia ogniska, tworzonego przez zwierciadło wklęsłe. Zaprezentowano przykład kaustyki powstającej przy odbiciu światła od zwierciadła wklęsłego. Na tym tle wskazano na możliwość powstawania kaustyk w pomieszczeniach. Szczególną uwagę zwrócono na duże pomieszczenia o charakterze historycznym, ze względu na częstą obecność w nich zwierciadeł akustycznych w postaci sklepień i...
-
Chitosan-based nanomaterials for removal of water pollutants
PublicationThe rise of micropollutants presents a significant threat to both the environment and human well-being, requiring effective strategies for their mitigation. Chitin serves as the precursor for chitosan, composed of two monomers featuring acetamido and amino groups. Chitosan possesses several noteworthy attributes, including its ability to bind water and fat, humidity content, solubility, consistent molecular weight, and various...
-
Dynamic tests of composite footbridge segment – experimental and numerical studies
PublicationExperimental dynamic tests and numerical simulations of a 3 meters long segment of a footbridge made of polymer composites are presented in the paper. The span-length is reduced, however dimensions of cross-section are the same as the target footbridge. The segment structure is made of sandwich panels, which consist of fibre reinforced polymer (GFRP) laminates (skins) and a PET foam (core). The first part of the paper contains...