Filters
total: 5005
-
Catalog
displaying 1000 best results Help
Search results for: LOWER AND UPPER SOLUTIONS
-
Water-Lubricated Sintered Bronze Journal Bearings—Theoretical and Experimental Research
PublicationWater lubricated bearings are used from many years in shipbuilding, hydro power and other industries because of their advantages such as: extensive serviceable life, low coefficient of friction, longevity of shaft sleeve, good abrasion resistance, low maintenance required, unit simplicity, no danger of pollution and low price. Various types of water lubricated sliding bearings have been tested at the Technical University of Gdansk...
-
Ground lemon and stevia leaves as renewable functional fillers with antioxidant activity for high-density polyethylene composites
PublicationThe development of new sustainable material solutions in the processing of thermoplastic polymers concerns both the application of biopolymers and the use of valorized plant derivatives as fillers and modifiers of petrochemical polymers. Herein, the possibility of using unprocessed raw parts of two commonly used in the food industry leaves, i.e., lemon (LL) and stevia (ST), as active and functional fillers for high-density polyethylene...
-
Latest Achievements in Concrete Structures Three-Dimensional Printing
PublicationWe can hear about three-dimensional printed concrete structures for several years, up to date solutions in this technology allow entire printing settlements of tiny concrete houses. Due to technical limitations, these houses are still small and not very durable, but undoubtedly, this technology is developing. Home printed in three-dimensional technology can be an alternative to modular container buildings implemented in areas affected...
-
Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete
PublicationHigh Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article...
-
Green, blue and energy in cities
PublicationThe article refers to the implementation of blue-green infrastructure in cities, with particular emphasis on the aspect of rainwater and energy management. The article presents the advantages of water and greenery in the city and gives examples of engineering solutions used, both the more popular (including green and biosolar roofs), as well as experimental solutions, which are an interesting and necessary alternative in the era...
-
Bifurcation of equilibrium forms of an elastic rod on a two-parameter Winkler foundation
PublicationWe consider two-parameter bifurcation of equilibrium states of an elastic rod on a deformable foundation. Our main theorem shows that bifurcation occurs if and only if the linearization of our problem has nontrivial solutions. In fact our proof, based on the concept of the Brouwer degree, gives more, namely that from each bifurcation point there branches off a continuum of solutions.
-
Strategies for Dealing With Software Product Management Challenges
PublicationSoftware product management, which involves multiple processes and responsibilities and links to many activities within the organisation, increases the success rate of IT projects. However, the adoption of product management activities and the implementation of the software product manager role itself varies between companies. This research explores the topic of software product managers’ strategies for dealing with challenges...
-
PROPRIETARY SOFTWARE IN TECHNICAL HIGHER EDUCATION
PublicationThe authors present a relatively easy way to extend the quality of education in professional studies (engineering) on major “Geodesy and Cartography”. They indicate the possibility to deepen students’ knowledge by using in the educational process proprietary software enriching education. The authors use their own experiences, results of the cooperation with employers, as well as the effects of scientific research to introduce into...
-
PROPRIETARY SOFTWARE IN TECHNICAL HIGHER EDUCATION
PublicationThe authors present a relatively easy way to extend the quality of education in professional studies (engineering) on major “Geodesy and Cartography”. They indicate the possibility to deepen students’ knowledge by using in the educational process proprietary software enriching education. The authors use their own experiences, results of the cooperation with employers, as well as the effects of scientific research to introduce...
-
Homoclinics for singular strong force Lagrangian systems
PublicationWe study the existence of homoclinic solutions for a class of generalized Lagrangian systems in the plane, with a C1-smooth potential with a single well of infinite depth at a point ξ and a unique strict global maximum 0 at the origin.Under a strong force condition around the singular point ξ, via minimization of an action integral, we will prove the existence of at least two geometrically distinct homoclinic solutions.
-
Comparison of oil yield and quality obtained by different extraction procedures from salmon (Salmo salar) processing byproducts
PublicationThe content and composition of lipids in different byproducts (skins, heads, and backbones) from mechanically processed farmed Atlantic salmon were determined and compared with that obtained from wild salmon. Three different procedures were used to establish the optimal conditions of oil extraction (at high temperature −95°C, “cold” extraction at temperature not exceeding 15°C and enzyme assisted with Alcalase). “Cold” extraction...
-
Jakub Szulwic dr inż.
PeopleJakub Szulwic (born 23 December 1974 in Bydgoszcz, Poland) – is an experienced, licensed Land Surveyor, specialized in construction monitoring by the use of photogrammetric methods and laser scanning technology. His specialization are geomatics and geoinformatics. He is an author about 100 publications including 50 indexed in Web of Science (H-index = 15) In 1993, He graduated from Secondary School in Tuchola, Poland on physics...
-
Comparative Analysis of Exoskeletal Actuators
PublicationSince the beginning of the development of exoskeletons in the early 1960s there was a constant need for improving their actuators technology. Requirements for high power and torque for the lower body and very high precision for the hand motion, while maintaining the flexibility of biological muscles, are still not fully satisfied. The problem lies not just in the lack of appropriate actuator technology, but also in the inability...
-
Shipping Safety Management on Polish Inland Waterways
PublicationOver the past years, the role of inland waterway transport has increased compared to other modes of transport. The increasing intensity of the inland vessel traffic significantly affects the safety of navigation. The article analyses the main causes of accidents and incidents that occurred on the Odra Waterway and Lower Vistula. The authors have classified those accidents and suggested possible directions for the development of...
-
Smart heating system for home extending utilization of renewable energy sources
PublicationIn the paper a modern approach to smart home heating is presented. Proposed solution utilizes at least two low-polluting energy source technologies. The main idea is to connect well known ecological energy sources in a way that they can support each other and minimize risks of failure when using single system or even both of them but managed in separate way. Considered energy technologies, used separatelly, have disadvan-tages,...
-
Magdalena Gajewska prof. dr hab. inż.
PeopleMagdalena Gajewska (born June 1th 1968 in Gdańsk) in 1993 graduated Hydro-Engineering Faculty at Gdańsk University of Technology. At present she is an assistant professor in the Department of Water and Wastewater Technology at the Faculty of Civil and Environmental Engineering GUT. PhD (2001) and habilitation (2013) in the discipline of environmental engineering. In the 2016-2020 term, serves as Vice -dean for science. She...
-
Porównanie obciążenia wiatrem wyznaczonego na podstawie procedur normowych z wynikami symulacji w cyfrowym tunelu aerodynamicznym dla hali stalowej.
PublicationW niniejszych badaniach porównano obciążenia od wiatru wyznaczonego metodą normową oraz w cyfrowym tunelu aerodynamicznym. Analizom poddano typowy budynek hali na planie prostokąta z dwuspadowym dachem w czterech wariantach geometrycznych. W pierwszym etapie budynki zwymiarowano bazując na obciążeniach od wiatru wyznaczonych według Eurokodu. Następnie dla poszczególnych elementów konstrukcyjnych określono poziom wytężenia. Dla...
-
Novel Family of Single-Phase Modified Impedance-Source Buck-Boost Multilevel Inverters With Reduced Switch Count
Publicationhis paper describes novel single-phase solutions with increased inverter voltage levels derived by means of a nonstandard inverter configuration and impedance source networks. Operation principles based on special modulation techniques are presented. Detailed component design guidelines along with simulation and experimental verification are also provided. Possible application fields are discussed, as well as advantages and disadvantages....
-
Laplace domain BEM for anisotropic transient elastodynamics
PublicationIn this paper, we describe Laplace domain boundary element method (BEM) for transient dynamic problems of three-dimensional finite homogeneous anisotropic linearly elastic solids. The employed boundary integral equations for displacements are regularized using the static traction fundamental solution. Modified integral expressions for the dynamic parts of anisotropic fundamental solutions and their first derivatives are obtained....
-
Technologies for deodorization of malodorous gases
PublicationThere is an increasing number of citizens’complaints about odor nuisance due to production or service activity. High socialawareness imposes pressure on entrepreneurs and service providers forcing them to undertake effective steps aimed at minimi-zation of the effects of their activity, also with respect to emission of malodorous substances. The article presents informationabout various technologies used for gas deodorization....
-
Wojciech Wyrzykowski dr hab.
PeopleWojciech Wyrzykowski is an employee of the Department of Finance at the Faculty of Management and Economics of the Gdańsk University of Technology. He is the author of 70 scientific publications, including 5 monographs, and co-author of 7 monographs. The most important of them reflecting the author's scientific interests include: Tax conditions for the development of entrepreneurship in Poland, Taxes in Poland - outline of the...
-
Nowy Orlean : zrobmy to porządnie
PublicationOpis społecznego projektu odbudowy dzielnicy Lower Ninth Ward, zniszczonej przez huragan Katrina w 2005 roku w Nowym Orleanie, realizowanego przez fundację Make it Right.
-
New Materiality-towards ‘Media Environments
PublicationArticle presents media solutions providing new materiality of architectural spaces. Media solutions in architecture evolve in new forms. Articlepresentsboth the developmentof new technological solutionsas well as new ways of application of media solutions in relation toarchitectural form. The aim of the article is to show technical aspects of new materiality - intelligent materials, allowing transmission of changeable visual content...
-
Time fractional analysis of Casson fluid with application of novel hybrid fractional derivative operator
PublicationA new approach is used to investigate the analytical solutions of the mathematical fractional Casson fluid model that is described by the Constant Proportional Caputo fractional operator having non-local and singular kernel near an infinitely vertical plate. The phenomenon has been expressed in terms of partial differential equations, and the governing equations were then transformed in non-dimensional form. For the sake of generalized...
-
SMG Monitoring system for maintaining cleanliness and order in the commune - SMG
ProjectsProject realized in Department of Geodesy according to POIR.01.01.01-00-0224/21 agreement from 2021-04-15
-
Can we really solve an arch stability problem?
PublicationWe bring attention to the problem of solving nonlinear boundary-value problems for elastic structures such as arches and shells. Here we discuss a classical problem of a shear-deformable arch postbuckling. Considering a postbuckling behaviour of a circular arch we discuss the possibility to find numerically a solution for highly nonlinear regimes. The main attention is paid to the problem of determination of all solutions. The...
-
Building modernization located in the conservation protection zone in the aspect of technical conditions
PublicationThe paper presents a description of the technical condition of the building after many years of operation and analyzes the impact of the current use and the lack of regular periodic repairs on the technical efficiency of the building. The influence of the technical solutions applied during the construction of the building on the current limitations related to the planned, target change in the way of use was discussed. Variant conceptual...
-
Smart Cities Concept: Smart Mobility Indicator
PublicationThis work attempts to analyze problems resulting from the lack of possibility to assess the effectiveness of the implementation of “Smart Mobility” solutions, which represent one of the cornerstones of Smart Cities, from the point of view of city hall offices. The work presents existing Smart Mobility evaluation solutions, discusses their drawbacks, and then proposes a new indicator. The final part of the work presents assumptions...
-
Miniaturized impedance analyzer using AD5933
PublicationThe paper presents the analyzer allowing to measure impedance in a range of 10 ohms <|Zx|<10 Gohms in a wide frequency range from 10 mHz up to 100 kHz. The device specific features are: miniaturization, low power consumptions and the use of impedance measurement method based on DSP. These features were possible thanks to the use of newest generation of large scale integration chips: e.g. „system on a chip” microsystems (AD5933)...
-
Miniaturized impedance analyzer using AD5933
PublicationThe paper presents the analyzer allowing to measure impedance in a range of 10 ohms <|Zx|<10 Gohms in a wide frequency range from 10 mHz up to 100 kHz. The device specific features are: miniaturization, low power consumptions and the use of impedance measurement method based on DSP. These features were possible thanks to the use of newest generation of large scale integration chips: e.g. „system on a chip” microsystems (AD5933)...
-
Liczby Ramseya on-line dla różnych klas grafów
PublicationRozpatrujemy grę rozgrywaną na nieskończonej liczbie wierzchołków, w której każda runda polega na wskazaniu krawędzi przez jednego gracza - Budowniczego oraz pokolorowaniu jej przez drugiego gracza - Malarkę na jeden z dwóch kolorów, czerwony lub niebieski. Celem Budowniczego jest zmuszenie Malarki do stworzenia monochromatycznej kopii wcześniej ustalonego grafu H w jak najmniejszej możliwej liczbie ruchów. Zakładamy, że gracze...
-
Synthesis of novel dinuclear ruthenium polypyridine dye for dye-sensitized solar cells application
PublicationA new dinuclear ruthenium(II) polypyridine complex has been successfully synthesized. The new compound has been characterized by spectroscopic and electrochemical methods. Its potential application as a sensitizing dye in dye-sensitized solar cells has been checked under AM 1.5 G irradiation conditions (100 mW cm−2) and its performance was compared to that of a commercially available mononuclear analogous dye. The overall light-to-electricity...
-
Detection of impulsive disturbances in archive audio signals
PublicationIn this paper the problem of detection of impulsive disturbances in archive audio signals is considered. It is shown that semi-causal/noncausal solutions based on joint evaluation of signal prediction errors and leave-one-out signal interpolation errors, allow one to noticeably improve detection results compared to the prediction-only based solutions. The proposed approaches are evaluated on a set of clean audio signals contaminated...
-
Mobility Oriented Development (MOD): Public-Private Partnership in Urban Parking & Traffic Management with the Use of Autonomous Automobiles, Car-Sharing, Ridesharing Modes of Transport & Mobility as a Service (MaaS)
PublicationThe focus of the following research are relations between mobility technologies and metropolitan (urban and suburban) spatial structures. In this paper the author discusses various urban modes of transport (automobile, mass transit) in the context of emerging technical (autonomous vehicles, self-driving cars and driverless shuttles) and organizational (carpooling, ridesharing, car-sharing, on-demand mobility) solutions for " mobility...
-
Distillery Fusel Oil as an Alternative Carbon Source for Denitrification – from Laboratory Experiments to Full-Scale Applications
PublicationIndustrial waste products may be a viable alternative to commercial external carbon sources, such as ethanol. In this study, the properties of fusel oil (distillery waste product) were investigated in terms of temperature dependency of denitrification, acclimation period, and the effects on NO2-N and PO4-P behavior. Furthermore, results obtained during three different full-scale trials were used to verify similarities and differences...
-
Routing decisions independent of queuing delays in broadband leo networks
PublicationThis paper presents an analysis of queuing and propagation delays of Inter-Satellite Links (ISLs) in broadband Low-Earth Orbit (LEO) satellite networks. It is shown that queuing delays are negligible in all reasonable working conditions of the broadband ISL network. This fact makes it possible to simplify the routing protocols in such networks and permits using already known multi-commodity flow solutions for routing. The performance...
-
Assessment of Connectivity-based Resilience to Attacks Against Multiple Nodes in SDNs
PublicationIn Software Defined Networks (SDNs), the control plane of a network is decoupled from its data plane. For scalability and robustness, the logically centralized control plane is implemented by physically placing different controllers throughout the network. The determination of the number and placement of controllers is known as the Controller Placement Problem (CPP). In the regular (i.e., failure-free) state, the control plane...
-
Anisotropic optical properties of few-layer black phosphorus coatings: from fundamental insights to opto-electrochemical sensor design
PublicationFew-layer black phosphorus (FLBP) is characterised by a tuneable bandgap, high carrier mobility and anisotropic optical properties. It therefore has the potential to find applications in electronics and photonics. FLBP oxidizes upon exposure to air, limiting its utility in devices and components. To address this issue, the thesis introduces methods and tools developed for studying FLBP's optical parameters, with a particular emphasis...
-
Measurements of Thermal Conductivity of LWC Cement Composites Using Simplified Laboratory Scale Method
PublicationThe implementation of low-energy construction includes aspects related to technological and material research regarding thermal insulation. New solutions are sought, firstly, to reduce heat losses and, secondly, to improve the environment conditions in isolated rooms. The effective heat resistance of insulating materials is inversely proportional to temperature and humidity. Cement composites filled with lightweight artificial...
-
Review and evaluation of cold recycling with bitumen emulsion and cement for rehabilitation of old pavements
PublicationThe article presents Polish experience with cold recycling of asphalt pavements with theusage of bituminous emulsion and cement. In the 1990s numerous roads in Polandrequired immediate reinforcement due to their significant degradation. Implementation ofthe cold recycling technology was one of the solutions to this problem. Cold recycledmixtures containebeside the recycled asphalt pavement and aggregateetwo differenttypes of binding...
-
Modernization and adaptation of historical interiors
PublicationModernization of the historical building's interior entails the need to take many decisions, often conflicting. Operational requirements, protection of the architectural heritage, fire-safety recommendations, construction regulations, all these aspects involve a whole set of problems that require a rational solution, respecting ambient architectural and historical value, as well as the needs arising from the planned transformation....
-
The reduction of vibrations in circular sawing machines
PublicationThe presented in this paper the main objectives of the research were to explore vibrations signals of the main spindle system, the machine tool body and a circular saw to extract informative features for assessment of the designs of the panel saw Fx3 and its follower Fx550.Even though the main spindle of the new table sliding saw Fx550 has its rotational speeds larger about 20% in comparison to the Fx3, peak values of the vibrational...
-
Distillery Fusel Oil as an Alternative Carbon Source for Denitrification – from Laboratory Experiments to Full-Scale Applications
PublicationIndustrial waste products may be a viable alternative to commercial external carbon sources. In this study, the properties of fusel oil (distillery waste product) were investigated in terms of temperature dependency of denitrification and acclimation period. Furthermore, results obtained during three different full-scale trials were used to verify similarities and differences with the results obtained under laboratory-scale conditions....
-
An additional ultrasonographic sign of Hashimoto’s lymphocytic thyroiditis in children
PublicationWe present an additional sonographic sign of Hashimoto’s thyroiditis (HLT), increasing the specifi city of this method in pediatric populations. Methods: A total of 98 children (mean age 12.7 years, range 7–17 years) were selected from the registry of the endocrinology outpatient department. All subjects met the diagnostic criteria for HLT. All children underwent a prospective thyroid ultrasound examination with special attention...
-
A Model-Driven Solution for Development of Multimedia Stream Processing Applications
PublicationThis paper presents results of action research related to model-driven solutions in the area of multimedia stream processing. The practical problem to be solved was the need to support application developers who make their multimedia stream processing applications in a supercomputer environment. The solution consists of a domain-specific visual language for composing complex services from simple services called Multimedia Stream...
-
IDENTIFICATION OF ODOR OF VOLATILE ORGANIC COMPOUNDS USING CLASSICAL SENSORY ANALYSIS AND ELECTRONIC NOSE TECHNIQUE
PublicationThe paper compares two methods of analysis of odour of volatile organic compounds: classical sensory analysis and electronic nose technique. Eight volunteers participated in the classical sensory analysis investigations, which lasted two weeks. An instrumental odour analysis involved a prototype of 6-sensor electronic nose designed by the authors. The research performed with this device provided higher reproducibility and reliability...
-
Cable-stayed bridges. Basic static schemes
PublicationThe paper presents an overview of shaping of cable-stayed bridges. Historical background, basic static sketches and overview of selected bridges are included. Selected natural solutions and interesting unrealized projects were presented. Basic ideas and most important principals are discussed. The examples and sketches were given an author's comment. Static diagrams of two pylon structures with three variants of the arrangement...
-
Application of short-time GNSS solution geodynamical studies
PublicationThe paper presents the results of research related to the application of GNSS solutions in short observational periods in geodynamical investigations. Authors used the 3-hour solution appointed from hour-long interval of about 30 chosen stations on mountainous terrains from over 100 which were worked out. The main aim was to check the correctness of such solutions by the comparison with the daily ones. Some outliers in East component...
-
The Antibacterial and Antifungal Textile Properties Functionalized by Bimetallic Nanoparticles of Ag/Cu with Different Structures
PublicationWe reported a preparation and characterization of five kinds of impregnation solutions, containing Ag/Cu in the formof bimetallic nanoparticles (alloy and core-shell) as well as ionic species. The cotton-polyester textiles were successfully impregnated during the washing and ironing process by as-prepared solutions to have antibacterial and antifungal properties against to Escherichia coli, Staphylococcus aureus, and Candida albicans....
-
Homoclinic and Heteroclinic Orbits for a Class of Singular Planar Newtonian Systems
PublicationThe study of existence and multiplicity of solutions of differential equations possessing a variational nature is a problem of great meaning since most of them derives from mechanics and physics. In particular, this relates to Hamiltonian systems including Newtonian ones. During the past thirty years there has been a great deal of progress in the use of variational methods to find periodic, homoclinic and heteroclinic solutions...