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Search results for: conchoidal path of contact
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Modelling of network schedule including priority of selected technical resources
PublicationThe paper presents a method of network planning CPM – Critical Path Method. The author compares models of optimal solutions to design deadlines for individual works, taking various leading technical resources such as is labor and a tower crane into account.
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Dorota Wojtowicz-Jankowska dr hab. inż. arch.
PeopleSenior lecturer at the Faculty of Architecture, Gdansk University of Technology. In the years 1996 - 2014 she worked at the Department of Public Utilities and she is currently employed at the Department of Environmental Design. In 2006 she was awarded the title of doctor. Since 2011 he has been a member of POIA RP. In the years 2014 - 2017 she was a member of the Faculty Council. In his research work, he deals with issues connected...
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The influence oil additives on spread cracks in silicon nitride
PublicationThe paper presents an experimental study of the influence of oil additives (Cl, S, P, cerium dioxide (CeO2)) on spread cracks in silicon nitride. The additives Cl, S, P are bound in molecules in liquid form soluble in the base oil. The CeO2 is purely in powder form in suspension. The use of CeO2 powder was made based on the good results of polishing of silicon nitride. A ceramic angular contact ball bearing was modelled using a...
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Mechatronic Design Towards Investigation of the Temporo-Mandibular Joint Behaviour
PublicationA significant problem of the temporo-mandibular joint (TMJ) research is lack of data concerning geometry and position of TMJ discs. It leads to necessity of developing a driving method of the process optimization, which is based on chosen techniques of mechatronic design. In particular, the latter concerns a technique of experimentally supported virtual prototyping. On this stage, the research is characterized by well-verified...
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Theoretical study of thermofrictional oscillations due to negative friction-temperature characteristic
PublicationAnalytical study on oscillations of a body on a moving counterbody has been done by assuming imperfect frictional thermal contact and friction that decreases with contact temperature. It has been shown that stick-slip oscillation occurs due to decrease of friction coefficient when the body moves in the opposite direction to the counterbody. Dynamical characteristics, such as conditions for stable sliding and limit cycles, have...
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The influence of the distance of the pyrometer from the surface of the radiating object on the accuracy of measurements
Open Research DataDuring the COVID-19 epidemic, non-contact body temperature measurement has become very important. This dataset contain results of measurements of the four professional commercially available pyrometers. The CHY 314P, TM-F03B, TFA 31.1125 and Abatronic AB-8855 where tested in function of measuring distance from the surface of the radiating black body....
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Recent Issues and Challenges in the Study of Inland Waters
PublicationThis paper addresses several important problems and methods related to studies of inland waters based on the existing scientific literature. The use of UAVs in freshwater monitoring is described, including recent contact and non-contact solutions. Due to a decline in biological diversity in many parts of the globe, the main threats are described together with a modern method for algae and cyanobacteria monitoring utilizing chlorophyll...
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Modelling of elastic wave propagation in a bolted joint using a thin layer of shell elements
PublicationThere are many mathematical models describing the propagation of elastic waves through the imperfect boundary of two media. They were successfully applied to modelling of high frequency bulk waves and their interaction with local defects. On the other hand, the existing literature models of bolted connections ignore the aspect of imperfect connection between elements. Therefore, this paper presents the concept of application of...
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Fading Characteristics for Dynamic Body-to-Body Channels in Indoor and Outdoor Environments
PublicationThis paper presents an analysis of the fading characteristics in dynamic body-to-body channels, based on measurements performed at 2.45 GHz in indoor and outdoor environments. The statistical analysis of the small- and large-scale fading shows that the Nakagami Distribution is the best model for the former and the Log-Normal one for the latter. An important influence of body shadowing...
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Fading Modelling in Dynamic Off-Body Channels
PublicationThis paper presents an off-body fading channel model for Body Area Networks. The proposed model, based on both simulations and measurements at 2.45 GHz in a realistic indoor environment, consists of three components: mean path loss, body shadowing, and multipath fading. The first is modelled as a log function of distance, the path loss exponent being in between 0.4 and 1.6. A statistical perspective is taken for the other two components,...
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A system for acoustic field measurement employing cartesian robot
PublicationA system setup for measurements of acoustic field, together with the results of 3D visualisations of acoustic energy flow are presented in the paper. Spatial sampling of the field is performed by a Cartesian robot. Automatization of the measurement process is achieved with the use of a specialized control system. The method is based on measuring the sound pressure (scalar) and particle velocity (vector) quantities. The aim of the...
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Characteristics of Propagation Conditions in the Container Terminal Environment
PublicationIn the paper a characteristics of propagation conditions in the container terminal environment is presented. The investigated environment is characterized on the example of Gdansk Deepwater Container Terminal in Poland. An empirical propagation model for path loss calculation in mobile radio links in a container terminal environment is presented.
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Influence of magnetic field on wear in high frequency reciprocatingsliding contacts
PublicationResults of experimental studies concerning the influence of permanent magnetic field on wear of dry sliding contact operating at short stroke and high frequency are presented. It was found that horizontal magnetic field with different orientations relative to the sliding direction is affecting performance of the contact. The increase in frequency of sliding reduces accumulated mass loss and lowers the surface roughness of the wear...
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The reliability of tree and star networks
PublicationThis paper investigated the reliability of tree and star networks. Following measures of network reliability are assumed: the expected number of nodes, that can communicate with the central node; the expected number of node pairs, that are connected by a path through the central node; the expected number of node pairs communicating.
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Proportional-Derivative and Model-Based Controllers for Control of a Variable Mass Manipulator
PublicationIn the paper, numerical analysis of dynamics of a variable mass manipulator is presented. A revolute joints composed manipulator is considered. Payload of the gripper is considered as the only element characterized by unknown value of its mass (variable between subsequent operations). As in other cases of the revolute joints composed manipulators, its behaviour dependents significantly on the pose of the manipulator. When the manipulator...
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Technical diagnostics and monitoring of traction current collectors
PublicationNew evaluation methods of the technical condition of rolling stock current collectors are proposed in this paper. The method of automatic measurement of the pantograph static force characteristic, realized when the vehicle runs through the test section of the track with especially prepared overhead line height distribution, has been practically implemented by the Polish Railways. The method of testing the slipper spring suspension...
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Influence of vision measurement system spatial configuration on measurement uncertainty, based on the example of electric traction application
PublicationTechnical diagnostics plays a significant role in ensuring operational reliability of electrified rail transport. The most critical point in the transmission of electric energy to vehicles is the sliding contact of the current collector with the traction network. For this reason, work is currently being carried on new measuring methods, whose appliance allows for more complete diagnostics of the contact line and current collectors,...
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Jeffreys heat conduction in coupled semispaces subjected to interfacial heating
PublicationA Jeffreys heat conduction problem for coupled semispaces subjected to the action of an interfacial heat source was defined. An analytical solution of the problem was derived for a polynomial specific power of the heat source using the Laplace transform approach. The asymptotic and parametric analysis was performed for different ratios of thermal conductivities , thermal diffusivities , thermal relaxation times and coefficients...
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Ryszard Woźniak dr inż.
PeopleRyszard Woźniak received his M.Sc. (1984) from the Lublin University of Technology specializing in Cars and Tractors. In 2002, at the Gdansk University of Technology he defended his doctoral thesis on: "Tyre/road noise when large longitudinal forces are applied in tyre/road contact patch" and obtained a doctorate degree in technical sciences in the field of construction and operation of machines. Currently he is an adjunct at the...
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Sieć sensorowa do rejestracji drgań górnej sieci trakcyjnej w celach diagnostyki eksploatacyjnej
PublicationWraz ze wzrostem prędkości kolejowych pojazdów elektrycznych zwiększają się wymagania utrzymania sieci trakcyjnej w odpowiednim stanie technicznym. Ciągły monitoring i diagnostyka pozwalają wykrywać pogarszającą się jakość odbioru prądu z sieci jezdnej. Jedną z metod jest umieszczenie czujników przyspieszenia na przewodzie jezdnym. Analiza przebiegu przyspieszenia pozwala określić jakość współpracy sieci jezdnej z pantografem....
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Crack propoagation in MgO-PSZ ceramic materials
PublicationThe properties of ceramic materials such as elevated hardness, high temperature capability, low coefficient of thermal expansion are of interest for rolling element materials. Widely used ceramic materials in engineering applications are silicon nitride, zirconia and alumina. The paper presents an experimental study of the fatigue life of MgO-PSZ ceramic material in lubricated contact with defined types of cracks. A ceramic angular...
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Energy roadmaps for the city of Gdańsk
PublicationThe paper presents energy roadmaps for Gdansk in three time perspectives: short-term (the year 2012), medium-term (2020) and long-term (2050). The paper is a result of the research carried out under the PATH-TO-RES project, supported by European Commission programme SAVE Altener Intelligent Energy Europe.
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Monitoring of current collectors on the railway line
PublicationProper cooperation the current collectors and the overhead line is a pre-requisite for reliable and safe operation of railway transport. Instances of maladjustment and, in some cases, damage to the current collectors, occur between periodic inspections of the rolling stock. In order to detect such anomalies quickly, the test stand was developed, with the aim of monitoring the technical state of the current collectors under operating...
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Modelowanie współpracy odbieraka prądu z siecią trakcyjną
PublicationW artykule przedstawiono aspekty oceny współpracy odbieraka prądu z górną siecią trakcyjną na podstawie porównania modeli matematycznych. Zaprezentowano modele odbieraków prądu i sieci jezdnej wskazując na ich użyteczność do oceny siły stykowej i uniesienia przewodów jezdnych. Wykonano szereg symulacji stanów dynamicznych interakcji górnej sieci trakcyjnej i odbieraka prądu dla różnych parametrów. W szczególności zwrócono uwagę...
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Impacts in case of triple unilaterally constrained system
PublicationThe this paper focus on the behaviour of a “rigid” body biting into another “rigid” body, with some nonzero relative velocity. In the presently considered case, the introduced collision appears between a selected element of a multibody structure and its reference body being interpreted as the motionless ground. Instead of the classic case, described in a number of dissertations, where a single impacting contact is considered, three...
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Client-server Approach in the Navigation System for the Blind
PublicationThe article presents the client‐server approach in the navigation system for the blind ‐ “Voice Maps”. The authors were among the main creators of the prototype and currently the commercialization phase is being finished. In the implemented prototype only exemplary, limited spatial data were used, therefore they could be stored and analysed (for path-finding process) in the mobile device’s memory without any difficulties. The...
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Mitigation effect of face shield to reduce SARS-CoV-2 airborne transmission risk: Preliminary simulations based on computed tomography
PublicationWe aimed to develop a model to quantitatively assess the potential effectiveness of face shield (visor) in reducing airborne transmission risk of the novel coronavirus SARS-CoV-2 during the current COVID-19 pandemic using the computational fluid dynamics (CFD) method. The studies with and without face shield in both an infected and healthy person have been considered in indoor environment simulation. In addition to the influence...
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Potentiometric sensor with lipid-polymer membranes for quality assessment of French red wines
PublicationThe quality of wines resulting from vineyard management is important for consumers due to the taste and price of wines. In this work, the quality of red wines of three vintages has been investigated by potentiometric sensors with six all-solid-state electrodes. Two series of experiments were carried out. The first involved a qualitative analysis of wine of different vintages from freshly opened bottles. The second consisted of...
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Mitigation effect of face shield to reduce SARS-CoV-2 airborne transmission risk: Preliminary simulations based on computed tomography
PublicationWe aimed to develop a model to quantitatively assess the potential effectiveness of face shield (visor) in reducing airborne transmission risk of the novel coronavirus SARS-CoV-2 during the current COVID-19 pandemic using the computational fluid dynamics (CFD) method. The studies with and without face shield in both an infected and healthy person have been considered in indoor environment simulation. In addition to the influence...
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Marek Chodnicki dr inż.
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Postquarter-Point Case of Ship’s Side-Berthing and Its Influence on Marine Fender Pitch
PublicationThis paper presents a critical analysis of some selected codes and practical recommendations used as basic rules in the design procedures of modern marine fender systems. The first part of the discussion pertains to the existing equations used in calculating the eccentricity coefficient in the ship’s kinetic energy equation and the maximum allowable fender pitch (spacing) in a set of fenders installed along a quay wall. A new approach...
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Investigation of the 0.4C-35Cr-45Ni-Nb Alloy after Service in High-Temperature Steam and Hydrocarbons Environment
PublicationThe paper presents the results of investigation of the 0.4C-35Cr-45Ni-Nb alloy, which operated in the cracked hydrocarbon feeds and dilution steam at 1125 C. The material originated from the pyrolytic furnace coil tubes, of which internal walls were in contact with the aforementioned medium, whereas the external walls were in contact with the flue gases. The examination included metallographic and mechanical tests on the material...
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Assessing Acute Toxicity and Endocrine Disruption Potential of Selected Packages Internal Layers Extracts
PublicationThe focus of the present study is migration of toxic substances from food contact materials and its actual influence on the health of the final consumer. Two food packagings (metal cans, TetraPack®) and five simulants medias (water, ethanol, acetic acid, DMSO, artificial saliva) were selected for simulation studies. For assessment of acute toxicity and endocrine disruption potential of extract samples, two biotests (Microtox® and...
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Allergic reactions as a defense of the organism to the influence of implants components made of stainless steel
PublicationDue to the increasing number of cases of hypersensitivity caused by direct contact with metals, as well as the increasing demand for implants in humans all ages numerous studies on the effects of the impact of implant components are being carried out. The paper presents the phenomenon of etiology of allergy in general terms and in relation to the biomaterials used in medicine. There have been characterized in terms of impact on...
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Allergic Reactions as a Defense of the Organism to the Influence of Implants Components Made of Stainless Steel
PublicationDue to the increasing number of cases of hypersensitivity caused by direct contact with metals, as well as the increasing demand for implants in humans all ages numerous studies on the effects of the impact of implant components are being carried out. The paper presents the phenomenon of etiology of allergy in general terms and in relation to the biomaterials used in medicine. There have been characterized in terms of impact on...
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The Impact Of The Selected Parameters Of Fdm Manufacturing Technology On Tribological Performance Of Abs–Steel Pair Under Dry Friction
PublicationThe paper presents the result of tribological test of ABS and steel samples sliding under dry friction. Polymeric samples were manufactured of ABS material using FDM technology. Testing was carried out in unidirectional sliding in a ring-on-flat contact in a PT-3 tribometer. The scope of tested parameters included volumetric and mass wear, the friction coefficient, and polymeric specimen temperature. Polymeric specimens used in...
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Multi-objective optimization of microwave couplers using corrected domain patching
PublicationPractical design of microwave components and circuits is a compromise between various, often conflicting objectives. In case of compact structures, the trade-offs are typically concerned with the circuit size and its electrical performance. Comprehensive information about the best possible trade-offs can be obtained by means of multi-objective optimization. In this paper, we propose a computationally efficient technique for identifying...
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Exploiting multi-interface networks: Connectivity and Cheapest Paths
PublicationLet G = (V,E) be a graph which models a set of wireless devices (nodes V) that can communicate by means of multiple radio interfaces, according to proximity and common interfaces (edges E). The problem of switching on (activating) the minimum cost set of interfaces at the nodes in order to guarantee the coverage of G was recently studied. A connection is covered (activated) when the endpoints of the corresponding edge share at...
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Badania eksperymentalne i symulacyjne dynamiki modelowego odcinka sieci trakcyjnej
PublicationW pracy przedstawiono główne założenia i strukturę opracowanego modelu matematycznego odcinka kolejowej górnej sieci trakcyjnej, opartego na metodzie energetycznej Lagrange’a. W celu wyznaczenia wybranych parametrów modelu, jak również dla oceny stopnia zgodności odwzorowania przez utworzony program symulacyjny stanów statycznych i dynamicznych sieci zbudowano laboratoryjny model odcinka sieci jezdnej z użyciem rzeczywistych jej...
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TOXICOLOGICAL ASSESSMENT OF FOOD PACKAGES EXTRACTS
PublicationIn the scientific literature related to the widely understood issue of packaging materials designed to have contact with food (Food Contact Materials – FCM) there is much information on raw materials used for their production, their physiochemical properties, types and parameters. There is also a great number of publications on the management and disposal of used packaging. Unfortunately, not much attention is given to the matters...
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Green function diagonal for a class of heat equations
PublicationA construction of the heat kernel diagonal is considered as element of generalized zeta function theory, which gradient at the origin defines determinant of a differential operator in a technique for regularizing quadratic path integral. Some classes of explicit expressions of the Green function in the case of finite-gap potential coefficient of the heat equation are constructed. An algorithm and program for Mathematica are presented...
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Reactions of methyl radicals with silica supported silver nanoparticles in aqueous solutions
PublicationSilica supported silver nanoparticles (Ag°–SiO2 –NCs, NCs=nanocomposites) suspended in aqueous solutions are efficient catalysts for the dimerization of methyl radicals to produce ethane, while bare silica is quite inert towards the interaction with methyl radicals. In the presence of small amounts of ethanol adsorbed on the SiO2 surface, the reaction path with methyl radicals is changed and methane is formed as the major product.
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Noise and Electro-Ultrasonic Spectroscopy of Conducting PolymerThick Films
PublicationThick conducting films based on conducting polymer are characterized by DC conductivity and noise in temperature range 10 to 300 K. Conducting polymers could be used e.g. for the top electrode (cathode) in the solid tantalum or niobium capacitors. On the conducting polymer layer the top layer of carbon/graphite and/or silver polymer based pastes is applied in the capacitor technology. Our samples structure consists of conducting...
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Personal history of chemotherapy for neoplastic disease - Female, 65 - Tissue image [6130730026859701]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 1000 slide scanner (20x magnification) and saved to DICOM format.
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Personal history of chemotherapy for neoplastic disease - Female, 65 - Tissue image [613073002685551]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 1000 slide scanner (20x magnification) and saved to DICOM format.
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Personal history of chemotherapy for neoplastic disease - Female, 65 - Tissue image [6130730026859191]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 1000 slide scanner (20x magnification) and saved to DICOM format.
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Single stillbirth - Female, 42 - Tissue image [12010630011261881]
Open Research DataThis is the histopathological image of PLACENTA tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Personal history of chemotherapy for neoplastic disease - Female, 65 - Tissue image [6130730026858401]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 1000 slide scanner (20x magnification) and saved to DICOM format.
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Personal history of chemotherapy for neoplastic disease - Female, 69 - Tissue image [6130730026856731]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 1000 slide scanner (20x magnification) and saved to DICOM format.
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Personal history of chemotherapy for neoplastic disease - Female, 69 - Tissue image [6130730026856861]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 1000 slide scanner (20x magnification) and saved to DICOM format.