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Wyniki wyszukiwania dla: climate change influence on hydrological and hydroacoustic conditions in baltic
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Negative impact of constant RPM control strategy on ship NOx emission in waves
PublikacjaIn severe wave conditions, the ship propulsion system is loaded with high fluctuations due to external disturbances. The highly fluctuating loads enforce radical changes in the main engine torque, which in turn demands variation of the fuel rate injected into the cylinders if a constant rotational speed strategy is applied. Therefore, the temperature of gases varies to a large extent during the combustion process in the cylinders....
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Recent Progress on Hydrogen Storage and Production Using Chemical Hydrogen Carriers
PublikacjaDepleting fossil fuel resources and anthropogenic climate changes are the reasons for the intensive development of new, sustainable technologies based on renewable energy sources. One of the most promising strategies is the utilization of hydrogen as an energy vector. However, the limiting issue for large-scale commercialization of hydrogen technologies is a safe, efficient, and economical method of gas storage. In industrial practice,...
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The impact of air humidity on the operation of proton exchange membrane fuel cells determined using dynamic electrochemical impedance spectroscopy
PublikacjaThis paper describes the changes in the fuel cell impedance across a range of current loads and humidity changes. The changes of each equivalent circuit parameters representing specific processes occurring in fuel cells, as a function of humidity and current changes, were determined. Within the combined scope of current and humidity, the optimal working conditions of the cells were determined, corresponding to the lowest impedance...
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Relieving the Measuring System of the Trailer for Tyre/Road Rolling Resistance Measurements from the Inertia Force
PublikacjaIn the article the principle of measuring of tyre/road rolling resistance tyres in road conditions applied in a special measuring trailer is presented. This trailer was built in Faculty of Mechanical Engineering at Gdansk University of Technology. The construction of two special devices used in this trailer was discussed. These devices eliminate the influence of some chosen confounding measurements factors such as: the inertia...
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Development of conductive porous media as packing materials for biotrickling filter – microbial fuel cell system (BTF-MFC system)
Dane BadawczeDataset presents values of electrical resistance measured for three developed conductive packimg materials for the application in a BTF-MFC system.
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Pyrolysis of Waste Biomass: Technical and Process Achievements, and Future Development-A Review
PublikacjaPyrolysis has been applied in the human economy for many years, and it has become a significant alternative to the production of chemical compounds, including biofuels. The article fo-cuses mostly on recent achievements in the technical and processing aspects of pyrolysis. The aim of the review is to present the latest research on the process of waste biomass pyrolysis to fuel production. The paper describes the mechanisms of...
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Evaluating the Catastrophic Rainfall of 14 July 2016 in the Catchment Basin of the Urbanized Strzyza Stream in Gdańsk, Poland
PublikacjaWe analyzed the causes, the course, and consequences of the extreme precipitation events that occurred 14 July 2016 in the watershed of Strzyza Creek in Gdańsk, Poland. Automated rain gauges located in Strzyża catchment registered a total precipitation lasting about 16 hours – from 129 to 160 mm of rain depth. More in-depth analysis based on rain data collected by Gdańsk University of Technology (GUT) rain station was done. The...
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Exploring DAD and ADD Methods for Dealing with Urban Heat Island Effect
PublikacjaThe Urban Heat Island (UHI) effect in the context of climate change and temperature fluctuations is an increasing challenge for contemporary cities. Numerous activities focus on mitigation and adaptation to the UHI effect using both appropriately selected design strategies and technological solutions. However, not all of these technologies support the postulates of ecological and low-carbon cities. Their design, implementation,...
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Management Strategy for Seaports Aspiring to Green Logistical Goals of IMO: Technology and Policy Solutions
PublikacjaRecently, because of serious global challenges including the consumption of energy and climate change, there has been an increase in interest in the environmental effect of port operations and expansion. More interestingly, a strategic tendency in seaport advancement has been to manage the seaport system using a model which balances environmental volatility and economic development demands. An energy efficient management system...
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Environmental impacts of food waste management technologies: A critical review of life cycle assessment (LCA) studies
PublikacjaFood waste is a serious global problem. Therefore, it is essential to reduce food waste and adopt recycling strategies to minimize its environmental impacts. However, conventional waste disposal methods emit harmful gases such as dioxin, CH4, N2O, and NH3, which contaminate the air and water resources. This work reviews the environmental consequences of food waste based on lifecycle assessment (LCA) techniques using methods such...
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Methane emissions from mangrove soils in hydrologically disturbed and reference mangrove tidal creeks in southwest Florida
PublikacjaStudies have suggested that some mangrove soils might contribute to wetland methane (CH4) production and emissions, especially when the mangroves are disturbed. CH4 emissions were measured seasonally from nine locations on two mangrove creeks on Naples Bay in southwest Florida, USA. One of the tidal creeks has been impacted in the past few decades with alteration of upstream watersheds and freshwater inflows; the other creek was...
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Enhanced Activity of P4503A4 and UGT1A10 Induced by Acridinone Derivatives C-1305 and C-1311 in MCF-7 and HCT116 Cancer Cells: Consequences for the Drugs’ Cytotoxicity, Metabolism and Cellular Response
PublikacjaActivity modulation of drug metabolism enzymes can change the biotransformation of chemotherapeutics and cellular responses induced by them. As a result, drug-drug interactions can be modified. Acridinone derivatives, represented here by C-1305 and C-1311, are potent anticancer drugs. Previous studies in non-cellular systems showed that they are mechanism-based inhibitors of cytochrome P4503A4 and undergo glucuronidation via UDP-glucuronosyltranspherase...
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Three-Dimensional Printing of Bone Models
PublikacjaThe trabecular bone occurs, for example, in the femoral heads. Understanding the phenomenon of bone tissue degeneration can be the basis for the possibility of looking for alternative methods of surgical treatment of bone loss. The paper presents the results of the trabecular bone model, which was produced in additive manufacturing method with fused filament fabrication technology. The verification of the mechanical behavior of...
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A method to determine the tightening sequence for standing rigging of a mast
PublikacjaThe article proposes an alternative method to determine the sequence of generation of pre-tension forces in standing rigging of a mast. The proposed approach has been verified on both a virtual simulation experiment and laboratory tests. In this method, the desired tension values are obtained using the influence matrix which allows to calculate the effect of tension change in an individual rope on the tension distribution in the...
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Frequency measurement research with weight averaging of pulse output signal of voltage-to-frequency converter
PublikacjaThe paper presents the essence and investigation of the efficiency of weight averaging of a pulse output signal of voltage-to-frequency converter. The effect of counting and the influence of interference on the result of weight averaging of frequency modulated pulses are analyzed. It is shown that from the point of view of counting error reduction, the best are polynomial weight functions. In the case of high interferences whose...
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Analysis of Factors Influencing the Prices of Tourist Offers
PublikacjaTourism is a significant branch of many world economies. Many factors influence the volume of tourist traffic and the prices of trips. There are factors that clearly affect tourism, such as COVID-19. The paper describes the methods of machine learning and process mining that allow for assessing the impact of various factors (micro, mezzo and macro) on the prices of tourist offers. The methods were used on large sets of real data...
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Straightened characteristics of McKendrick-von Foerster equation
PublikacjaWe study the McKendrick-von Foerster equation with renewal (that is the age-structured model, with total population dependent coefficient and nonlinearity). By using a change of variables, the model is then transformed to a standard age-structured model in which the total population dependent coefficient of the transport term reduces to a constant 1. We use this transformation to get existence, uniqueness of solutions of the problem...
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Analysis of Methods for Determining Shallow Waterbody Depths Based on Images Taken by Unmanned Aerial Vehicles
PublikacjaHydrographic surveys enable the acquisition and processing of bathymetric data, which after being plotted onto nautical charts, can help to ensure safety of navigation, monitor changes in the coastal zone, and assess hydro-engineering structure conditions. This study involves the measurement of waterbody depth, identification of the seabed shape and geomorphology, the coastline course, and the location of underwater obstacles....
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Stormwater and snowmelt runoff storage control and flash flood hazard forecasting in the urbanized coastal basin.
PublikacjaCity of Gdańsk is located in a coastal region where changing climatic conditions increase the frequency of extreme weather events. Developing urbanization affects the hydrology of natural basins by simplification of the drainage system and reduction of infiltration and base flow. Consequently greater runoff rates flow into storm water collection systems, reservoirs and surrounding water bodies. Not only infrastructures of urban...
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Stormwater runoff in the urbanized coastal basin of Gdańsk Urbanized basin of Gdańsk
PublikacjaAnthropopressure strongly affects the primal water cycle. Alternation of the natural basins imposes changes of drainage patterns, reduction of bioretention, infiltration and base flow. As a result the overland flow predominates and greater runoff rates flow into storm water collection systems and reservoirs. Moreover changing climatic conditions increase the frequency of rapid extreme weather events. Infrastructures of urban areas...
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Review of methods for assessing traffic conditions on basic motorway and expressway sections
PublikacjaMotorways and expressways are the core of each country’s road system. Road planning, design and management requires tools to ensure that roads have the right geometry, traffic layout and equipment. These include methods for capacity estimation and assessing traffic conditions. Because the paper focusses on the basic segments of motorways and expressways (sections located between interchanges and outside of their influence), its...
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Occurrence and properties of sulphate reducing bacteria in groundwater in Gdańsk region; Selected methods of elimination.Bakterie redukujące siarczany na ujęciach wód podziemnych w regionie gdańskim.
PublikacjaGdańsk region is situated in the area with good hydrogeological conditions. The ground-water designed for drinking purposes is taken mainly from the Quaternary and addition-ally from Cretaceous aquifers. The urban development and intensive take off have caused the increase of water exploitation and as a consequence of the changes of hydrogeological conditions the deterioration of chemical and bacteriological quality of water has...
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The Influence of Workpiece Hardness on Plate Temperature during One Side Lapping
PublikacjaLapping leads to a surface with low roughness and high precision. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. The goal was to determine the correlation between the basic lapping conditions and wheel temperature. In work Bulsara et al. authors developed model to estimate the maximum and average temperature...
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Analysing the impact of traffic incidents on express road traffic flow using FREEVAL
PublikacjaTraffic incidents occurring on motorways or express roads cause disruptions and deteriorate traffic conditions. The impact will differ depending on the type of incident, its duration and space blocked on the roadway and can be measured with e.g. average speed reduction, extension of travel time, time lost or overall costs of traffic disruptions. The aim of the paper is to analyse this impact, based on data from the Tri-City Ring...
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Uncertainty of antioxidant profiling in complex mixtures using liquid chromatography involving post-column derivatisation
PublikacjaThe main goal of this paper is to discuss the problems associated with antioxidant profiling in complex samples using a high-throughput HPLC system coupled with post-column derivatisation reactor. Based on the experimental data reported in the literature, we demonstrated that improper optimisation of temperature and/or pH assay conditions performed using an on-line derivatisation reactor may substantially change the antioxidant...
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Profile irregularities of turned surfaces as a result of machine tool interactions
PublikacjaThe paper describes the influence of the machining operation on a surface, which disturbs the projection of the tool profile in the form of its relative movements with respect to the object. The elements of the machine tool undergo constant wear during the machining process, it is therefore important to recognize the effects of their influence on the surface's irregularities. Amplitude-frequency analysis of lateral profiles has...
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A SEARCH OF AN INDUCER GEOMETRY THAT IS BENEFICIAL FOR LIFTING PARAMETERS OF A LIFTED OBJECT OF A SELECTED SHAPE
PublikacjaThe literature describes acoustic levitation phenomena with the utilization of air squeeze film between the vibrating inducer and the lifted object. The objective of the study is to determine the shape of the inducer with vibration characteristics that would allow the levitation of an object of the assumed geometry. In this paper, the influence of the dimension ratio of the inducer on the frequency of the first mode of vibration...
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Analysis and comparision of safety of children and adult passanger in car based on crash tests results
PublikacjaThis paper presents analysis and comparision of safety of children and adult passanger in car based on crash tests results. The car crash test with four dummies, including two car seats allowed a direct comparison of the security under the same conditions of children and passengers directly to the car seat. Analysis of acceleration and video from the test allows to understand the phenomena during the collision, the air bags influence,...
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Cavitation wearing of the SUPERSTON alloy after laser treatment at cryogenic conditions
PublikacjaThe purpose of this paper is to demonstrate the method of laser remelting at cryogenic conditions of the SUPERSTON alloy and its influence on microstructure and cavitation wearing. The cavitation test was performed using the rotating disc facility in IPM PAN Gdansk. During the cavitation test, the mass loss of the material with different parameters of laser remelting was determined. Surface and cross-section microstructure of the...
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Prediction of flow boiling heat transfer coefficient for carbon dioxide in minichannels and conventional channels
PublikacjaIn the paper are presented the results of calculations using authors own model to predict heat transfer coefficient during flow boiling for carbon dioxide. The experimental data from various researches were scrutinised conducted for a full range of quality variation and wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house model. The work shows the importance of taking into account surface...
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INVESTIGATION INTO INTERFEROMETRIC SONAR SYSTEM ACCURACY
PublikacjaThe results of the accuracy measurements of phase differencing bathymetric sonar (PDBS) system in shallow waters are presented in the article. The measurement results were compared with the theoretical calculations for sonar system accuracy and international standards for hydrographic surveys. The proposed formulas enable to assess a priori sonar system performance using system quality factor (SQF), which takes into account influence...
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Study of Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublikacjaA new technique, which was developed to characterize the direct methanol fuel cell under work conditions, has been presented in this paper. The impedance measurements were made using dynamic electrochemical impedance spectroscopy research technique in the galvanostatic mode, using multiple sinusoidal excitation. Obtained results show, that together with an increase of the temperature and working load, the global impedance...
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Microstructure and residual stresses in surface coatings with PTFE reservoirs
PublikacjaThe paper presents the results of experimental study into the microstructure and changes in residual stresses resulting from sliding and rolling/sliding loaded interaction between metallic surface coatings with embedded PTFE reservoirs and various counter faces. It was found that before testing surface coatings had compressive residual stresses. Molybdenum coating with all types of PTFE reservoirs displayed, as a result of testing,...
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Possible effects of the 1984 St. Clair River ice jam on bed changes
PublikacjaThis study examines the possible effect of the record ice jam of 1984 in the St. Clair River on river bed changes and conveyance. Numerical simulations were made to examine the flow and bed shear stresses during the jam formation and release periods. Simulation results indicate that the ice jam in the river did not cause a significant increase in bed shear stress compared to pre- and post-jam open water conditions. The insignificant...
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Biomass Production and Removal of Nitrogen and Phosphorus from Processed Municipal Wastewater by Salix schwerinii: A Field Trial
PublikacjaIn many Baltic regions, short-rotation willow (Salix spp.) is used as a vegetation filter for wastewater treatment and recycling of valuable nutrients to upsurge bioeconomy development. In this context, a four-year field trial (2016–2019) was carried out near a wastewater treatment plant in eastern Finland (Outokumpu) to investigate the effect of the processed wastewater (WW) on biomass production as well as the nutrients uptake...
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Polymer based thick films - material quality and interface resistance evaluation
PublikacjaThe properties of polymer based thick film layers mede using different resistive pastes and dipping silvers have been studied. The composite of carbon and graphite (C/Gr) conducting particles suspended in different polymer vehicles were used for preparation resistive layers. Interface resistance Rc created between dipping silver (DiAg) contact layer and resistive layer was determined from the surface potential distribution measurements...
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Effects of full displacement pile installation on the stress and deformation state of surrounding soil: review
PublikacjaSeveral field and model tests have been conducted to investigate the impact of pile installation on bearing capacity. However, little is known about how piles behave during installation, how they interact with the surrounding soil, and how this affects sandy soil properties. This review paper investigates the effect of pile driving on surrounding sandy soil as it compacts sandy soil near to the pile. For this purpose, various related...
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X-RAY DIFFRACTION STUDY OF BISMUTH LAYER-STRUCTURED MULTIFERROIC CERAMICS
PublikacjaGoal of the present research was to apply a solid state reaction route to fabricate bismuth layer-structured multiferroic ceramics described with the formula Bi5FeTi3O15 and reveal the influence of processing conditions on its crystal structure and phase composition. Simple oxide powders Bi2O3, TiO2 and Fe2O3 were used to fabricate Aurivillius-type bismuth layer-structured ferroelectrics. Pressureless sintering in ambient air was...
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Optical and chemical characterization of thin TiNx films deposited by DC-magnetron sputtering
PublikacjaThin titanium nitride (tinx) films were deposited on silicon substrates by means of a reactive dc-magnetron plasma. Layers were synthesized under various conditions of discharge power and nitrogen flows in two operation modes of the magnetron (the so-called "balanced" and "unbalanced" modes). The optical constants of the tinx films were investigated by spectroscopic ellipsometry (se). X-ray photoelectron spectroscopy (xps) was...
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Organic and conventional kiwifruit, myths versus reality: antioxidant, antiproliferative and helth effects
PublikacjaComparison between organic and conventional kiwifruit cultivars 'Hayward' and 'Bidan', which was done by four radical scavenging assays, ESI-MS, and DSC measurements, showed significant differences between the cultivars. Such results were not estimated in kiwifruit growing under organic and conventional conditions. The extraction of bioactive compounds was done by two different methods: sequential extraction with ethyl acetate...
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Enhanced Electrochemical Performance of MnCo1.5Fe0.5O4Spinel for Oxygen Evolution Reaction through Heat Treatment
PublikacjaMnCo1.5Fe0.5O4 spinel oxide was synthesized using the sol−gel technique, followed by heat treatment at various temperatures (400, 600, 800, and 1000 °C). The prepared materials were examined as anode electrocatalysts for watersplitting systems in alkaline environments. Solid-state characterization methods, such as powder X-ray diffraction and X-ray absorption spectroscopy (XAS), were used to analyze the materials’ crystallographic...
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Numerical Study of the Impinging Jets Formed by an Injector with Different Nozzle Diameters
PublikacjaThe collision of two or more liquid jets may provide considerable atomisation and efficient mixing of injected substances at the same time. This phenomenon is used, among others, in rocket engines, where the fuel and oxidiser are introduced separately and almost immediately mixed through self-impingement. Depending on the injection and operating conditions, diverse configurations of impinging jets are used, such as doublets,...
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Quality of graphical markers for the needs of eyewear devices
Publikacjain this paper we propose to cast the problem of identification of people, objects or places into an application for smart glasses that decodes information from graphical markers. We focus on analyzing different factors that can have influence on the processes of the automatic recognition of information from a code. The research we present aims at reviewing recognition performances in function of: size of a marker, distance from/to...
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Bacterial presence in polar regions associated with environment modification by chemical compounds including contaminants
PublikacjaMicrobes are omnipresent and diverse members of all biological communities. In marine and freshwater ecosystems, microorganisms form the base of the food chain supporting higher trophic levels. Even though, microbes generally are thought to live in warm regions of Earth, many of them develop in cold climates. Polar regions remain relatively protected from widespread anthropogenic disturbances, which is a consequence of its remoteness...
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HEAVE MOTION OF A VERTICAL CYLINDER WITH HEAVE PLATES
PublikacjaThe shape of a vertical cylinder resembles the classic form of a spar platform. Spar platforms are floating platforms that are successfully used in waters of great depths and have several advantages that mean they are readily used in the oil industry. Many of these advantages are also relevant to their application for offshore wind turbines, which is currently being considered. In the hydrodynamic analysis of spar platforms, the...
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Polynomial analysis as a new way of describing dynamic impedance spectra – Differential and relative impedance spectra
PublikacjaModel measurements of an equivalent electrical system were carried out using the technique of Dynamic Electrochemical Impedance Spectroscopy. The measurement took the form of potentiodynamic changes imposed on the tested system. Using the possibility of continuous impedance measurements, an attempt was made to develop an original and innovative method of analyzing impedance spectrograms, which is termed polynomial analysis. As...
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Electrochemical Activity and Electrical Properties of Optimized Polypyrrole Coatings on Iron
PublikacjaIn this work, electrochemical activity and electrical properties of polypyrrole (PPy) coated iron electrodes have been investigated. PPy film was electrochemically polymerized from sodium salicylate aqueous solution under conditions, which provided an increase of iron corrosion resistance. It was noticed that the pH of the solution and the applied electrode potential range during the study of the polymer properties had an influence...
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Degradation of stiffness of building columns exposed to bending and impact load during ground motions
PublikacjaThe safety of civil engineering structures under external loads, including ground motions, is one of the issues related to the idea of sustainable society. The earthquake-induced soft-storey failure is a typical type of damage observed in buildings due to seismic excitation. The failure of an intermediate soft storey of a structure results in large vertical impact loading acting on the lower floors due to the fall of the upper...
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Delivery of Ancillary Services in Distribution Power Systems
PublikacjaOne of the technical and organizational challenges the power system faces in deregulated market conditions is to organize an ancillary services market. The growing share of distributed generation of variable (intermittent) energy sources and a change in the market position of consumers, causes the demand for distributed delivery of ancillary services. For this purpose, it is sought to use the ability of the regulatory measures:...
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Dynamic impedance measurements of the Direct Methanol Fuel Cell cathode at various operating temperatures
PublikacjaThis article discusses the application of impedance analysis for diagnosing the cathode of a direct methanol fuel cell at various operating temperatures. The Dynamic Electrochemical Impedance Spectroscopy technique coupled with a linear current scan was applied for this purpose. This technique allowed the observation of changes in the cathode's properties in the fuel cell operating under real working conditions. An equivalent model...