Search
Filters
total: 1596
filtered: 1470
displaying 1000 best results Help
Search results for: SHEAR DEMANDS
-
THEORETICAL POTENTIAL OF HYDROGEN PRODUCTION FROM TEXTILES WASTES IN POMERANIAN REGION BY MEANS OF DARK FERMENTATION
PublicationModel has been developed for calculating theoretical mass of hydrogen produced from textile wastes by mean of dark fermentation. As vegetable fibres wastes were chosen two mostly used — cotton and linen (flax). As the synthethic carbohydrate rich fiber was chosen viscose. In the background there were introduced: problems of dark fermentation, characteristics of textile material structure. Additionally pathways of the process...
-
Analysis of the Impact of Charging Electric Cars on the Power System Load
PublicationThe paper presents ways of integrating electric cars with the power system. In connection with this, daily load curves in the average working day have been developed in the G2V (Grid-to-Vehicle) and V2G (Vehicle-to-Grid) variants. The G2V solution consists in unidirectional energy flow from the power system to a vehicle’s battery. The V2G solution consists in bi-directional energy exchange between the power system and electric...
-
The potential of web awareness as a determinant of dually defined customer value
PublicationIn the conditions of increasing demand barrier, the enterprise’s basic capital is customers. From an enterprise point of view, this means the need to create a dual perceived and defined customer value which remains related to market value (income and development potential) and customer resource value (reference, information and cooperative potential). The progressing digitisation process transfers business processes, and thus relationships, into...
-
Model based evaluation of plant improvement at a large wastewater treatment plant (WWTP)
PublicationIn this work, the effect of the improvement carried out at a large-scale wastewater treatment plant (WWTP) was evaluated, by means of modelling works, with the aim to determine the influence of the modernization over the process performance. After modernization, the energy consumption due to the aeration decreased about a 20% maintaining the effluent quality. In order to double-check the good effluent quality, modelling works were...
-
INFLUENCE OF DATA NORMALIZATION ON THE EFFECTIVENESS OF NEURAL NETWORKS APPLIED TO CLASSIFICATION OF PAVEMENT CONDITIONS – CASE STUDY
PublicationIn recent years automatic classification employing machine learning seems to be in high demand for tele-informatic-based solutions. An example of such solutions are intelligent transportation systems (ITS), in which various factors are taken into account. The subject of the study presented is the impact of data pre-processing and normalization on the accuracy and training effectiveness of artificial neural networks in the case...
-
Comparative study of operation of condensing and traditional boilers equipped with the ORC module for electricity generation
PublicationCondensing technology applied to boilers is to make full use of thermal energy contained in the fuel. That means that additionaly the heat from condensation of exhaust gases can be used for the purposes of heating the domestic hot water and to cover the demand for central heating. The study analyzed the operation of the "traditional" boiler equipped with the ORC module as the similar arrangement but with the condensing boiler....
-
Implementation of SiN thin film in fiber-optic sensor working in telecommunication range of wavelengths
PublicationMirrors are used in optical sensors and measurement setups. This creates a demand for mirrors made of new materials and having various properties tailored to specific applications. In this work, we propose silicon covered with a thin silicon nitride layer as a mirror for near-infrared measurements. SiN layer was deposited on a standard silicon wafer with a Low-Pressure Chemical Vapor Deposition furnace. Then, the created layer...
-
A study of jet impingement cooling enhancement by concave and convex heat sink shape modifications
PublicationThe rising demand for efficient cooling technologies is a strong driver of extensive research in this area. This trend is particularly strong in turbines and microprocessors technology. Presented study is focused on the jet impingement cooling concept, which is used in various configurations for many years. The potential of the heat sink shape modification is not yet fully explored. Available literature suggests that average Nusselt...
-
Production and Properties of the Porous Layer Obtained by the Electrochemical Method on the Surface of Austenitic Steel
Publication: The growing demand for implants has seen increasing interest in the introduction of new technologies and surface modification methods of metal biomaterials. This research aimed to produce and characterize a porous layer grown on austenitic stainless steel 316L, obtained via the anodization process near the micro-arc oxidation, i.e., low voltage micro-arc oxidation (LVMAO). The discussed layer significantly influences the properties...
-
Within- and between-firm wage inequalities and trade integration in GVC
PublicationThis paper examines between- (inter) and within- (intra) firm wage inequality using rich employer-employee data for 12 European countries. We confirm that much overall wage inequality is observed within sectors and within occupations. The share of the within- and between-firm components in overall wage inequality varies across countries. We estimate the link between involvement in global value chains (GVCs) and wages differentiating...
-
Multi-objective optimization of the ORC axial turbine for a waste heat recovery system working in two modes: cogeneration and condensation
PublicationDue to the demand of the district heating network and electric power grid ORC turbines can operate in the condensation and cogeneration modes. This approach requires the design of an expander which is characterized by high efficiency in each mode of operation. The paper is devoted to a multi-objective efficiency optimization of a one stage axial ORC turbine working on MM (Hexamethyldisiloxane). An Implicit Filtering algorithm (IF)...
-
Analyzing content of tasks in Business Process Management. Blending task execution and organization perspectives
PublicationAn efficient organization, management, and execution of tasks are central for the successful functioning of any organization. This topic was on the research agenda already in the early 1950s and keeps attracting the scientific community's attention today. Continuous advances and penetration of technologies in organizations are expected to increase task variety and complexity. This creates a constant demand for new methods to analyze,...
-
APPLICABILITY OF INLET AIR FOGGING TO MARINE GAS TURBINE
PublicationThe dependency of marine gas turbine on the ambient temperature leads to a decrease of the gas turbine power output in arid areas. Very often gas turbine power output demand is high and the power margins originally designed into the driver , has been exhausted. In such circumstances the inlet air fogging is an effective compensation of gas turbine power. In this paper an analysis of inlet air fogging applicability to marine gas...
-
A negative effect of carbon phase on specific capacity of electrode material consisted of nanosized bismuth vanadate embedded in carbonaceous matrix
PublicationLithium-ion batteries (LIBs) are widely used all over the world. The LIBs belong to a renewable energy source and energy storage devices. The increase in energy demand causes that new materials of higher energy and higher power densities are still under investigation. Herein, we compare electrochemical properties of bismuth vanadate (BiVO4) embedded and not embedded into carbonaceous matrix as an anode material along with structural...
-
Risks caused by microbiologically influenced corrosion in diesel fuel storage tanks
PublicationMicrobiologically influenced corrosion (MIC) poses serious problems for the petrochemical and refinery industries. Particularly favourable conditions for MIC arise in storage tanks and transmission pipelines for mixtures of diesel oil with the addition of a biocomponent (in Poland 7%). The best conditions for the development of MIC occur at the fuel-water interface, where microorganisms are provided with a source of food and water,...
-
Multimedia services applied to noise and hearing monitoring and measuring
PublicationThe goal of this chapter is to show a research study related to processing of data acquired by the multimedia services engineered at the multimedia systems department (MSD) of the Gdansk University of Technology. This concerns a survey on noise threat employing the multimedia noise monitoring system (MNMS) and hearing tests performed by the "I can hear. . . " system. The obtained results of the noise measurements revealed that...
-
Możliwości zastosowań, potencjalne źródła oraz ewolucja technologiczna sposobu otrzymywania trehalozy ze szczególnym uwzględnieniem enzymu syntazy trehalozy [EC 5.4.99.16]
PublicationJedna z wiodących gałęzi współczesnej biotechnologii opiera się na produkcji białek – przede wszystkim enzymów. Są one powszechnie wykorzystywane: od przemysłu chemicznego poprzez przemysł spożywczy aż po medycynę i życie codzienne (czy ktoś wyobraża sobie w dzisiejszych czasach proszek do prania „bez enzymu”). Przed rozwojem nowoczesnych metod biologii molekularnej i inżynierii genetycznej pozyskiwano interesujące substancje z...
-
Thriving in multicultural work settings
PublicationOwing to globalization and the global mobility of workforce, working in multicultural environments has become a daily reality for an increasing number of manpower. Such an environment does introduce unique challenges to individuals, enabling some of them to thrive. The aim of the paper, therefore, is to explore the antecedents of thriving and its components in multicultural work settings of multinational corporations (MNCs). The...
-
Static Shunt PE Voltage-Quality Controllers
PublicationThis chapter focuses on power electronics (PE)-based solutions used in distribution networks for reduction of supply-voltage-quality deterioration, from long interruptions to the harmonics. Various PE devices and their combinations are addressed for particular or a range of voltage disturbances. A particular solution is applied taking into account demands for voltage quality and network configuration. In general, there are three...
-
Efficient Simulation-Based Global Antenna Optimization Using Characteristic Point Method and Nature-Inspired Metaheuristics
PublicationAntenna structures are designed nowadays to fulfil rigorous demands, including multi-band operation, where the center frequencies need to be precisely allocated at the assumed targets while improving other features, such as impedance matching. Achieving this requires simultaneous optimization of antenna geometry parameters. When considering multimodal problems or if a reasonable initial design is not at hand, one needs to rely...
-
Shielded HMSIW-based frequency-tunable self-quadruplexing antenna using different solid/liquid dielectrics
PublicationThis article proposes a frequency-tunable self-quadruplexing antenna based on a shielded half-mode substrate integrated waveguide (S-HMSIW). In order to reduce the size of the HMSIW cavity resonator and to obtain quad-band characteristics, a modied E-shaped slot is engraved on the top of the metal. The experimental validation is carried out after analyzing the data using a circuit model. Flexibility of each resonant frequency is...
-
Planning Around Polarisation: Components of Finding Common Ground Based on Regeneration Projects in London and Gdańsk
PublicationVarious forms of public participation in urban design and planning—as presented and discussed in literature—have recently been challenged by the needs and expectations of different stakeholders, including those coming from the private sector. This comes with a redefinition of the public good and the roles and responsibilities of municipal authorities in post‐liberal times. As a result, contemporary participatory processes need...
-
Supercomputing Grid-Based Services for Hearing Protection and Acoustical Urban Planning, Research and Education
PublicationSpecific computational environments, so-called domain grids, are developed within the PLGrid Plus project in order to prepare specialized IT solutions, i.e., dedicated software implementations and hardware (infrastructure adaptation), suited for particular research group demands. One of the PLGrid Plus domain grids, presented in this paper, is Acoustics. The article describes in detail two kinds of the acoustic domain services....
-
Creating Dynamic Maps of Noise Threat Using PL-Grid Infrastructure
PublicationThe paper presents functionality and operation results of a system for creating dynamic maps of acoustic noise employing the PL-Grid infrastructure extended with a distributed sensor network. The work presented provides a demonstration of the services being prepared within the PLGrid Plus project for measuring, modeling and rendering data related to noise level distribution in city agglomerations. Specific computational environments,...
-
Application of Traction Supply System for Charging Electric Cars
PublicationThe development of electromobility involves the development of electric cars charging infrastructure. The increase of the number of chargers poses new demands for the AC power grid, especially in regard to its capacity of delivering high peak power. As an alternative for the public AC power grid, urban electrified transportation systems (trams, trolleybuses, and metro) can be used for supplying electric cars chargers. The article...
-
Optimization-based antenna miniaturization using adaptively-adjusted penalty factors
PublicationThe continuing trend for miniaturization of electronic devices necessitates size reduction of the comprising components and circuitry. Specifically, integrated circuit-antenna modules therein require compact radiators in applications such as 5G communications, implantable and on-body devices, or internet of things (IoT). The conflict between the demands for compact size and elec-trical and field performance can be mitigated by...
-
Negative impact of constant RPM control strategy on ship NOx emission in waves
PublicationIn 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....
-
Spirometry measurement model - the diagnostic purpose support
Publicationthe paper presents a new model of respiratory mechanism based on the spirometry measurements. the spirometry test assesses the efficiency of the lung ventilation. the respiratory system functioning is based on the ventilation mechanism. thus the quality of the lung depends on the quality of lung ventilation. modelling of the respiratory system supports a diagnostic process. the model parameter estimates are obtained on the basis...
-
Disturbances of magnetic field in surrounding of mobile, metalic plate
PublicationThe uniform magnetic field of the Earth in the surrounding of a mobile, metalic object undergoes deformation by eddy currents. The influence of the moving conducting object on total magnetic field of the Earth depends on the object's shape, position and speed of the changes relative to the magnetic field's vector of the Earth as well as the electric conductivity and the relative magnetic permeability of the material. The disturbances...
-
Electrohydrodynamic secondary flow and particle collection efficiency in spike-plate multi-electrode electrostatic precipitator
PublicationIn this work the results of electrohydrodynamic (EHD) secondary flow measurements in a spike-plate type electrostatic precipitator (ESP) are presented. In the investigated ESP two-sided and one-sided spike electrodes were used as a discharge electrodes. The results of 2D PIV measurements showed that flow pattern obtained for a different spike tips positions in respect to the primary flow direction significantly changing the flow...
-
Electrohydrodynamic Secondary Flow and Particle Collection Efficiency in Spike-Plate Multi-Electrode Electrostatic Precipitator
PublicationIn this work the results of electrohydrodynamic (EHD) secondary flowmeasurements in a spike-plate type electrostatic precipitator (ESP) are presented. In the investigated ESP two-sided and one-sided spike electrodes were used as a discharge electrodes. The results of 2D PIVmeasurements showed that flow pattern obtained for a different spike tips positions in respect to the primary flow direction significantly changing the flow...
-
Optimization of Self-Organized TiO2 Nanotube Geometry on Ti and Ti Alloys Using Fuzzy Logic Reasoning
PublicationThe geometry of self-organized TiO2 nanotubes, obtained by electrochemicalanodization, has been determined by using fuzzy reasoning approach. The efficiency of TiO2nanotubular layer in biomedical applications depends on geometry and available surface area ofnanotubes, which can be determined by their diameter and length. The structure of nanotubesdepends on processing parameters of electrochemical anodization, like applied potential,anodization...
-
Positive solutions to fractional differential equations involving Stieltjes integral conditions
PublicationIn this paper, we investigate nonlocal boundary value problems for fractional differential equations with dependence on the first-order derivatives and deviating arguments. Sufficient conditions which guarantee the existence of at least three positive solutions are new and obtained by using the Avery–Peterson theorem. We discuss problems (1) and (2) when argument b can change the character on [0, 1], so in some subinterval I of...
-
Slurry Erosion -Design of Test Devices
PublicationDegradation of material caused by impacts of a solid particle (erodent) suspended in a liquid is called slurry erosion and is a major problem in the hydropower and maritime industry. Slurry erosion depends on many factors, e.g. liquid and erodent velocity, size, shape, angle of impact, hardness and number of erodents, and strength of a target material. The various types of test devices have been designed to investigate an effect...
-
Regression points in non-intrusive polynomial chaos expansion method and D-optimal design
PublicationThe paper addresses selected issues of uncertainty quantification in the modelling of a system containing surgical mesh used in ventral hernia repair. Uncertainties in the models occur e.g. due to variability of abdominal wall properties among others. In order to include them, a non-intrusive regression-based polynomial chaos expansion method is employed. Its accuracy depends on the choice of regression points. In the study a relation...
-
Determinants of the surface quality, density and dimensional correctness in selective laser melting of the Ti-13Zr-13Nb alloy
PublicationSelective laser melting is widely used for custom-designed elements. Successful manufacturing depends on laser treatment parameters and material features. This research aimed to determine the effects of laser power, scan time and hatch distance on surface quality, relative density and dimensional precision for cuboids made of the Ti-13Zr-13Nb alloy. The influence of energy density, energy flux and pre-heating was seen to be decisive...
-
Weak Solutions within the Gradient-Incomplete Strain-Gradient Elasticity
PublicationIn this paper we consider existence and uniqueness of the three-dimensional static boundary-value problems in the framework of so-called gradient-incomplete strain-gradient elasticity. We call the strain-gradient elasticity model gradient-incomplete such model where the considered strain energy density depends on displacements and only on some specific partial derivatives of displacements of first- and second-order. Such models...
-
Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
PublicationThis paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in...
-
Analysis of the Usefulness of Cheap Audio Recorders for Spectral Measurement of Environmental Noise
PublicationEnvironmental noise pollution is nowadays one of the most serious health threats. The impact of noise on the human body depends not only on the sound level but also on its spectral distribution. Reliable measurements of the environmental noise spectrum are often hampered by the very high price of top quality measuring devices. This paper explores the possibility of using much cheaper audio recorders for the frequency analysis....
-
Analiza porównawcza metod zwiększania nośności i sztywności stalowych, doczołowych węzłów śrubowych.
PublicationInnowacyjna, w porównaniu z dotychczas stosowanym sposobem, metoda obliczania nośności stalowych węzłów została wdrożona wraz z normami europejskimi. Pozwala ona dokładniej odwzo-rować rzeczywistą pracę poszczególnych części węzła, gdyż wynik obliczeń uzależniony jest od znacznie większej liczby zmiennych. Dzięki postępowi technologicznemu w zakresie metalurgii oraz badaniom naukowym obecnie możliwe jest wzmacnianie połączeń...
-
Ranking of ecotoxisity tests for underground water assessment using the Hasse diagram technique
PublicationThe present study deals with the novel application of the Hasse diagram technique (HDT) for the specific ranking of ecotoxicity tests capable of assessment of underground water quality. The area studied is a multi-municipal landfill in the northern Poland. The monitoring network of the landfill constitutes of 27 piezometers for underground water monitoring and two observation points at surface water courses. After sampling, chemical...
-
Joint foreign ownership and global value chains effects on productivity: a comparison of firms from Poland and Germany
PublicationPurpose The study aims to examine the joint effects of foreign ownership (FO) and involvement in global value chains (GVCs) on the productivity performance of firms from a catching-up country (Poland) and a leader economy (Germany). Design/methodology/approach The authors use micro-level data on firms combined with several sector-level GVC participation measures. The authors investigate whether the link between productivity and...
-
One Year Evaluation of Material Properties Changes of Polylactide Parts in Various Hydrolytic Degradation Conditions
PublicationBiodegradable biocompatible materials are widely used in medical applications. Determining the possibility of using biodegradable materials depends on determining the changes in their parameters over time due to degradation. The current scientific research on biodegradable materials has presented results based on research methods characterized by the different geometry and cross-section size of the specimen, type of degradation...
-
Development and evaluation of thermosensitive hydrogels with binary mixture of Scutellariae baicalensis radix extract and chitosan for periodontal diseases treatment.
PublicationScutellaria baicalensis root displays anti-inflammatory and antibacterial properties due to the presence of flavonoids, particularly baicalin, baicalein, and wogonin. Our work aimed at developing thermosensitive hydrogels containing a binary mixture of S. baicalensis radix lyophilized extract and chitosan as a novel approach for periodontal diseases treatment....
-
Development and validation of lumbar spine finite element model
PublicationThe functional biomechanics of the lumbar spine have been better understood by finite element method (FEM) simulations. However, there are still areas where the behavior of soft tissues can be better modeled or described in a different way. The purpose of this research is to develop and validate a lumbar spine section intended for biomechanical research. A FE model of the 50th percentile adult male (AM) Total Human Model for Safety...
-
Modes of Failure Analysis in Reinforced Concrete Beam Using Laser Scanning and Synchro-Photogrammetry - How to apply optical technologies in the diagnosis of reinforced concrete elements?
PublicationThe following paper reveal the limitations and possibilities of terrestrial laser scanning technology adaptation in diagnostics of reinforced concrete beams. In this paper, authors present potential spectrum of TLS use in modes of failure analysis of R-C beams and determines under which conditions the laser technologies might be applied. Research was carried out at the Regional Laboratory of Structural Engineering at Gdansk University...
-
Fruit seeds oils as a cosmetic emulsions component
PublicationThe fruit seeds are known to have a considerable amount of oil and their potential specialty as nutraceutical oil was suggested based on high level of unsaturated triacyglycerols (major fatty acids are linoleic, linolenic, oleic) and a high content of tocols (tocopherols and tocotrienols). In this study the possibility of application fruit seeds oils in W/O and O/W emulsion systems was investigated to find the influence of the...
-
Modes of Failure Analysis in Reinforced Concrete Beam Using Laser Scanning and Synchro-Photogrammetry
PublicationThe following paper reveal the limitations and possibilities of terrestrial laser scanning technology adaptation in diagnostics of reinforced concrete beams. In this paper, authors present potential spectrum of TLS use in modes of failure analysis of R-C beams and determines under which conditions the laser technologies might be applied. Research was carried out at the Regional Laboratory of Structural Engineering at Gdansk University...
-
NEW EXPERIENCES IN DIKE CONSTRUCTION WITH SOIL-ASH COMPOSITESAND FINE-GRAINED DREDGED MATERIALS
PublicationThe supporting structure inside a coastal dike is often made of dredged non-uniform sand with good compaction proper-ties. Due to the shortage of natural construction material for both coastal and river dikes and the surplus of different processed mate-rials, new experiments were made with sand-ash mixtures and fine-grained dredged materials to replace both dike core and dikecover materials resulting in economical, environmentally...
-
Management of ground tire rubber waste by incorporation into polyurethane-based composite foams
PublicationRapid economic growth implicated the developing multiple industry sectors, including the automotive branch, increasing waste generation since recycling and utilization methods have not been established simultaneously. A very severe threat is the generation of enormous amounts of post-consumer tires considered burdensome waste, e.g., due to the substantial emissions of volatile organic compounds (VOCs). Therefore, it is essential...