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Wyniki wyszukiwania dla: MECHANICAL LOSS
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Application of Doubly Connected Dominating Sets to Safe Rectangular Smart Grids
PublikacjaSmart grids, together with the Internet of Things, are considered to be the future of the electric energy world. This is possible through a two-way communication between nodes of the grids and computer processing. It is necessary that the communication is easy and safe, and the distance between a point of demand and supply is short, to reduce the electricity loss. All these requirements should be met at the lowest possible cost....
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Overview of Approaches for Compensating Inherent Metamaterials Losses
PublikacjaMetamaterials are synthetic composite structures with extraordinary electromagnetic properties not readily accessible in ordinary materials. These media attracted massive attention due to their exotic characteristics. However, several issues have been encountered, such as the narrow bandwidth and inherent losses that restrict the spectrum and the variety of their applications. The losses have become the principal limiting factor...
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Hybrid Approach to Networked Control System
PublikacjaEffcient control of Networked Control System (NCS) is a challenge, as the control methods need to deal with non-deterministic variable delays and data loss. This paper presents a novel hybrid approach to NCS where Model Predictive Control (MPC) is applied as a main controller and implicit switching MPC is used for data transmission control in event-driven shared communication medium, leading to complex control system with active...
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Naprawa przegubów Estakady Kwiatkowskiego w Gdyni = Hinges repair og the E. Kwiatkowskiego trestle bridge in Gdynia
PublikacjaE. Kwiatkowskiego trestle bridge is one of the main parts of road infrastructure that connects sea transport (container terminal BTC) national roads A1,1,7. Every limitation of motor traffic causes many problems for Gdynia inhabitants and moreover economical loss in transport economy. In recent two years there were expertise and repair project of hinges carried out. Paper presents genesis and reasons of hinges damages, theoretical...
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Influence of dipoles on the recombination in organic photovoltaic devices
PublikacjaAlthough organic compounds are promising materials to use them in photovoltaic devices, the efficiencies of organic solar cells are still lower in comparison to inorganic photocells. The recombination of charge carriers leads to the loss of photocurrent, therefore a detailed theoretical description of this process is required. In the present work, an influence of interface dipoles on the recombination process is discussed. We show...
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The photocurrent quantum efficiency dependence on the applied voltage in organic solar cells
PublikacjaWe demonstrate that our recently reported model (Szmytkowski 2007 J. Phys. D: Appl. Phys. 40 3352) of the photocurrent quantum efficiency in organic semiconductors explains the external quantum efficiency dependence on the electric field in organic solar cells. This effect can be explained by taking into account that the photogeneration of charge carriers occurs via the electron-hole pair dissociation and the space charge effects...
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Ultra-Wideband Vivaldi Antenna with an Integrated Noise-Rejecting Parasitic Notch Filter for Online Partial Discharge Detection
PublikacjaPower transformers and gas-insulated switchgear (GIS) play crucial roles in electrical power grids. However, they may suffer from degradation of insulation material due to wear and tear, leading to their imminent failure. Partial discharges (PDs) are an initial sign of insulation materials degradation which emit signals spanning various physical domains, including electromagnetic. PDs are temporally narrow, high-frequency, stochastic...
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Knowledge Safety – Insights from the SME Sector
PublikacjaPurpose: This paper aims to explore the topic of knowledge safety, defined as the state of knowledge being safe from loss, leakage, attrition, oblivion, waste or theft. The paper first presents a theoretical background and review of previous studies on knowledge loss and ways of overcoming it, and then illustrates the topic of knowledge safety with ten case studies from the small and medium-sized enterprises (SMEs) sector. Methodology:...
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Diamond surface modification following thermal etching of Si supported hydrogenated diamond films by DBr
PublikacjaZbadano, wykorzystując spektroskopię oscylacyjną (HREELS - High Resolution Electron Energy Loss Spectroscopy) modyfikacje chemiczne powierzchni wodorowanego diamentu, umieszczonego na podkładzie krzemowym i wystawionego na działanie DBr a następnie podgrzanego do temp. powyżej 600 st.K. Przedstawiona procedura powoduje tworzenie się węglika krzemu SiC na powierzchni warstwy diamentowej, co jest widoczne na widmie HREEL jako dwa...
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Influence of magnetic field on wear in high frequency reciprocatingsliding contacts
PublikacjaResults 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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Path Loss Modelling for Location Service Applications
PublikacjaThe aim of this paper is the path loss modeling for the radiolocation services in radiocommunication networks, particularly in cellular networks. The main results of the measurements obtained in the physical layer of the UMTS are introduced. A new method for the utilization of the multipath propagation phenomenon to improve the estimation of the distance between the mobile station (MS) and the base station (BS) is outlined. This...
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Ellipticity of gradient poroelasticity
PublikacjaWe discuss the ellipticity properties of an enhanced model of poroelastic continua called dilatational strain gradient elasticity. Within the theory there exists a deformation energy density given as a function of strains and gradient of dilatation. We show that the equilibrium equations are elliptic in the sense of Douglis–Nirenberg. These conditions are more general than the ordinary and strong ellipticity but keep almost all...
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Experimental and numerical analysis of the pyrolysis dynamics of a single wood particle: presentation of the radiographic technique
PublikacjaPyrolysis is an oxygen-free process for the thermal decomposition of raw materials. The heat conduction and flow of pyrolysis products (i.e., the gas fraction and liquid vapour generated during pyrolysis) influence the process and products. In this work, the influence of the orientation of wooden particle fibres with respect to the direction of the heat source on the dynamics of the process was investigated, where there were two...
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Laxer Clinical Criteria for Gaming Disorder May Hinder Future Efforts to Devise an Efficient Diagnostic Approach: A Tree-Based Model Study
PublikacjaInternet Gaming Disorder (IGD) has been recognized in May 2013 and can be evaluated using the criteria developed by American Psychiatric Association (APA). The present study investigated the role each IGD criteria plays in diagnosing disordered gaming. A total of 3,377 participants (mean age 20 years, SD = 4.3 years) participated in the study. The data collected was scrutinized to detect patterns...
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Investigating the disease- modifying properties of sclerotiorin in Alzheimer's therapy using acetylcholinesterase inhibition
PublikacjaAlzheimer's disease (AD) is a progressive neurodegenerative disorder caused due to the damage and loss of neurons in specific brain regions. It is the most common form of dementia observed in older people. The symptoms start with memory loss and gradually cause the inability to speak and do day-to-day activities. The cost of caring for those affected individuals is huge and is probably beyond most developing countries capability....
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Analysis of the Possibility of Using New Types of Protective Coatings and Abrasion-Resistant Linings under the Operating Conditions of the Spiral Classifier at KGHM Polska Miedź S.A. Ore Concentration Plant
PublikacjaA study was carried out to select the appropriate coatings for corrosion protection of the spiral classifier working at KGHM Polska Miedź S.A. Ore Concentration Plant. The abrasion resistance of selected protective coatings and wear-resistant linings was investigated using a DT-523 rotary abrasion tester with Taber CS-10 rubber abrasive discs. The average weight loss of the coatings after a cycle of 2000 revolutions was determined....
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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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PROBLEMS OF EXPERIMENTAL DETERMINATION OF COEFFICIENTS OF THE WEAR OF SHIP PIPING SYSTEMS
PublikacjaThe article presents series of considerations relating to experimental evaluation of the reliability of ship piping systems. The aim of this study is to attempt to answer the following questions: What should be the tested element? How to choose the diameter of the tested item? What should be the result of measurements and calculations? How to measure? How to choose the duration of the test? How to choose the sample size and elaborate...
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Measurement Stand and Methodology for Research of the Off-Body and Body-to-Body Radio Channels in WBANs with Different Diversity Schemes
PublikacjaThe concept of an experimental test bed for system loss and channel impulse response measurements for off-body and body-to-body radio channels in wireless body area networks (WBANs) is fully described. The possible measurement scenarios that may occur in investigation of off-body and body-to-body channels are classified and described in detail. Additionally, an evaluation is provided of the standard and expanded uncertainties of...
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VUV irradiation studies of plasmid DNA in aqueous solution
PublikacjaInteractions of VUV light and DNA samples in aqueous solutions are reported. The damage induced by such radiation is quantified by monitoring both loss of supercoiled DNA and formation of single and double strand breaks using agarose gel electrophoresis. Irradiations were performed using synchrotron VUV photons of 130, 150, 170 and 190 nm. VUV irradiation experiments revealed enhanced damage upon irradiation with 170 nm photons...
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Styrene Oxidation by Copper(II) Complexes Salen-Type Encapsulated into Nay Zeolite
PublikacjaThe copper(II) complex with a Schiff-base salen-type ligand has been encapsulated in the nanopores of a NaY zeolite by using two different methodologies, the flexible ligand and in situ complex preparation methods. The encapsulated and non-encapsulated copper(II) complexes were screened as catalysts for styrene oxidation by using TBHP as the oxygen source in acetonitrile solvent. Under the optimized conditions, the catalysts exhibited...
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The use of Response Surface Methodology for reliability estimation of aluminum silo subjected to wind load
PublikacjaAn axisymmetric aluminum silo model with a single, standardized geometric imperfection of its lateral surface is considered. The silo is wind – loaded only. The paper is focused on the critical, or limit value of wind pressure, both producing a loss of stability of the silo. This value is affected by vertical coordinate (position) of the imperfection and the angular relation between the imperfection and the wind direction. Reliability...
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Electron energy-loss spectroscopy of excited states of the pyridine molecules
PublikacjaElectron energy-loss spectra of the pyridine, C5H5N, molecules in the gas phase have been measured to investigate electronic excitation in the energy range 3.5–10 eV. The applied wide range of residual electron energy and the scattering angle range from 10 ◦ to 180 ◦ enabled to differentiate between optically-allowed and -forbidden transitions. These measurements have allowed vertical excitation energies of the triplet excited...
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Performance of ASON/GMPLS architecture in condition of wavelength conversion and without wavelength conversion
PublikacjaThe paper regards the problem of ASON/GMPLS performance in condition of wavelength and without wavelength conversion. The authors present influence analysis in condition of wavelength and non-wavelength conversion on the ASON/GMPLS control plane performance represented by mean Connection Set-up Time E (CST) and request loss probabilities. The offered traffic to the transport layer and request intensity have been changed for evaluation...
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Cavitation Erosion of P110 Steel in Different Drilling Muds
PublikacjaThe P110 steel specimens were subjected to ultrasonic cavitation erosion in different compositions of drilling muds and surfactant additive. The test procedure was based on ASTM-G-32 standard recommendations. API 5CT-P110 steel is used for pipes in oil and gas industry. The harsh environment and high velocity of flows poses corrosive and erosive threat on materials used there. The composition of drilling fluid influences its rheological...
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A Method and Device for 3D Recognition of Cutting Edge Micro Geometry
PublikacjaA very useful method was successfully applied in the investigation of tools for machining wood and wood based composites. It allows scanning of the cutting edge micro geometry in three dimensions and reproducing it in a virtual space as a 3D surface. The application of the method opens new possibilities of studying tool wear by scanning, including the calculation of volume loss and other analysis of tool wedge geometry along and...
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Experimental and numerical study on stability loss of innovative geometry steel girder
PublikacjaThis paper presents the experimental and numerical analysis of an innovative plate girder geometry with variable web thicknesses. An idea proposed in this research is to increase the stability of the girder web by increasing its thickness in the compressed zone. This solution can replace commonly used longitudinal stiffeners which are designed to prevent web local loss of stability. Moreover, such an innovative approach requires...
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Smart Approach for Glioma Segmentation in Magnetic Resonance Imaging using Modified Convolutional Network Architecture (U-NET)
PublikacjaSegmentation of a brain tumor from magnetic resonance multimodal images is a challenging task in the field of medical imaging. The vast diversity in potential target regions, appearance and multifarious intensity threshold levels of various tumor types are few of the major factors that affect segmentation results. An accurate diagnosis and its treatment demand strict delineation of the tumor affected tissues. Herein, we focus on...
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Simulator for Performance Evaluation of ASON/GMPLS Network
PublikacjaThe hierarchical control plane network architecture of Automatically Switched Optical Network with utilization of Generalized Multi-Protocol Label Switching protocols is compliant to next generation networks requirements and can supply connections with required quality of service, even with incomplete domain information. Considering connection control, connection management and network management, the controllers of this architecture...
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Radio Channel Measurements in Off-Body Communications in a Ferry Passenger Cabin
PublikacjaThis paper presents an off-body radio channel measurements in a ferry passenger cabin at 2.45 GHz band, for static sleeping scenarios with different body orientation and on-body antennas placements, and also for upper and lower sleeping berths. The measurements have been performed with two types of on-body wearable receiving antennas: FlexPIFA (flexible planar inverted F antenna), and FlexNotch (flexible adhesive-backed notch antenna)...
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A Novel [4+2] Cycloaddition Reaction Involving Lawesson’s Reagent. Structure and Specific Fragmentations of a New Cyclic 1,2-Thiaphosphinane-4-one
PublikacjaA crude morpholine enamine of acetone treated with Lawesson’s reagent unexpectedly yielded a six-membered thiaphosphinane-4-one. This compound is the first example of a new class of heterocycles. It has been proven that it is formed from 4-methyl-2-morpholino-1,3-pentadiene which is usually present in crude morpholine enamine batches. A mechanism of this regioselective reaction was postulated and a characteristic chair-like conformation...
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Using Wearable Electronics to Estimate Usefulness of Heart Rate Variability for Bathing Person Identif Cation
PublikacjaIn this paper the possibility of person identification based on biosignal is investigated. The work focus on the analysis of the changes in intervals between successive R-waves of electrocardiogram (ECG) recorded by wearable electronics in form of a necklaces. The main idea behind this project is to find efficient tool which may prevent sudden consciousness loss episodes or even sudden death episodes related to rapid temperature...
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Adaptive dynamic control allocation for over-actuated dynamic positioning system based on backstepping method in case of thruster faults
PublikacjaThe objective of the research considered in this paper is dynamic positioning of a nonlinear over-actuated marine vessel in the presence of limited information about thruster forces. First, the adaptive backstepping method is used to estimate the input matrix which will compensate partial loss of actuator effectiveness in the presence of actuator dynamics. Then, the adaptive commanded virtual forces and moment are allocated into...
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Performance analysis of an rfid-based 3d indoor positioning system combining scene analysis and neural network methods
PublikacjaThe main purpose of this research is to improve localization accuracy of an active Radio Frequency Identification, RFID tag, in 3D indoor space. The paper presents a new RFID based 3D Indoor Positioning System which shows performance improvement. The proposed positioning system combines two methods: the Scene Analysis technique and Artificial Neural Network. The results of both simulation using Log-Distance Path Loss Model and...
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Empirical Propagation Model for the Container Terminal Environment
PublikacjaIn the paper the empirical propagation model for mobile radio links in a container terminal environment is presented and the investigated environment Deepwater Container Terminal in Gdansk, Poland) is characterized. Described empirical model was elaborated on the basis of almost 290 thousand propagation path measurements in real conditions. The diversity of conditions occurring in different places of the container terminal has...
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Elliptical slot UWB monopole antenna
PublikacjaThe UWB monopole antenna with elliptical radiating slot end and microstrip feeding line terminated with radial stub have been designed, fabricated and measured. The antenna show return loss less than -12 dB in the whole UWB bandwidth. Linearity of the reflection coefficient phase product have also been achieved. Radiation patterns of the antenna measured at three selected frequency points indicated regular, approximately omni directional...
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Evolutionary Sets of Safe Ship Trajectories: problem dedicated operators
PublikacjaThe paper presents the optimization process of the evolutionary sets of safe ship trajectories method, with a focus on its problem-dedicated operators. The method utilizes a customized evolutionary algorithm to solve a constrained optimization problem. This problem is defined as finding a set of cooperating trajectories (a set is an evolutionary individual) of all the ships involved in the encounter situation. The resulting trajectories...
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Analysis of pressure ratio in the intake in dependence on high-voltage behaviours
PublikacjaPower control in spark ignition engines by regulating the intake air is performed. The control unit needs information about the air pressure conditions which then enters the combustion chamber. The information about the intake air pressure is an important quantity for optimal control of combustion mixtures. The paper describes some types of sensors that are used to measure the air intake temperature. Air pressure in the intake...
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The field–dependent interface recombination velocity for organic–inorganic heterojunction
PublikacjaWe have derived an analytical formula which describes the field–dependent interface recombination velocity for the boundary of two materials characterized by different permittivities. The interface recombination of charge carriers has been considered in the presence of image force Schottky barrier. We suggest that this effect may play an important role in the loss of current for organic–inorganic hybrid heterojunctions. It has...
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THE PHASE SHIFTERS INFLUENCE ON THE POWER SYSTEM STABILITY
PublikacjaThe paper presents the effect of phase shifters as FACTS devices on the possibility of improving the angle stability. Presented results obtained by the dynamic simulation performed on the mathematical model of the three machine system cooperating with the 400 kV network. The generative blocks models include turbine models with their controllers and models of synchronous generators with their excitation systems and voltage regulation....
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Low-Loss 3D-Printed Waveguide Filters Based on Deformed Dual-Mode Cavity Resonators
PublikacjaThis paper introduces a new type of waveguide filter with smooth profile, based on specially designed dual-mode (DM) cavity resonators. The DM cavity design is achieved by applying a shape deformation scheme. The coupling between the two orthogonal cavity modes is implemented by breaking the symmetry of the structure, thus eliminating the need for additional coupling elements. The modes operating in the cavity are carefully analyzed...
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Locust bean gum as green and water-soluble binder for LiFePO4 and Li4Ti5O12 electrodes
PublikacjaLocust Bean Gum (LBG, carob bean gum) was investigated as an environmentally friendly, natural, and water-soluble binder for cathode (LFP) and anode (LTO) in lithium-ion batteries (Li-ion). For the frst time, we show LBG as an electrode binder and compare to those of the most popular aqueous (CMC) and conventional (PVDF) binders. The electrodes were characterized using TGA/DSC, the galvanostatic charge–discharge cycle test, cyclic...
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Characteristics of LaCo 0.4 Ni 0.6-x Cu x O 3-δ ceramics as a cathode material for intermediate-temperature solid oxide fuel cells
PublikacjaIn this study, the effects of Cu-ion substitution on the densification, microstructure, and physical properties of LaCo0.4Ni0.6-xCuxO3-δ ceramics were investigated. The results indicate that doping with Cu ions not only enhances the densification but also promotes the grain growth of LaCo0.4Ni0.6-xCuxO3-δ ceramics. The Cu substitution at x ≤ 0.2 can suppress the formation of La4Ni3O10, while the excess Cu triggers the formation...
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Scheduling jobs to contain a natural disaster: a model and complexity
Publikacjathis paper is devoted to the problem of scheduling suppression units so that a natural disaster is dealt with as efficient as possible. the concept of deteriorating jobs is adopted, that is, the formal model of scheduling represents linearly increasing value loss as the disaster remains unsuppressed and increasing time for its suppression. more precisely, two different goals are considered: finding a suppression schedule of minimal...
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Cavitation erosion degradation of Belzona® coatings
PublikacjaIn hydrocarbon and maritime industry there is a constant need of materials and coatings withstanding severe conditions. One of adverse phenomena present there is cavitation erosion. The paper presents evaluation of cavitation resistance of three different steel coatings. Belzona 2141 (ACR-Fluid Elastormer), 1321 (Ceramic S-Steal) and 5831 (ST-Barrier) were deployed on P110 steel and subjected to ultrasound cavitation in distilled...
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Adhesion of organic coatings to hot-dip galvanized steel
PublikacjaDuplex systems provide long-time corrosion protection, much longer than the sum of the lifetimes of zinc and paint used individually. However loss of adhesion between coating and zinc substrate is often found in practice. Different methods of zinc surface preparations are used in the fi eld. The aim of this study was to examine and compare coating protection when the old zinc surface, stored during long-time period (15 years) in...
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Possibilities of radioisotope measuring in control of an unstable solid particles hydrotransport
PublikacjaThe paper presents γ-radiation proposal to control a multiphase flow, independently from circumstances. So this method may be applied even in compound industrial or environmental processes. Moreover in many cases, it is the only method for applications for dense mixture containing coarse angular grains. The constructed equipment allows continuous measurement of density as well as solid phase for both concentration and average velocity....
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Acoustics - new services for urban planning, research and education
PublikacjaThe main purpose of the presented design is twofold, namely: providing detailed information about the noise threats that occur every day in city areas and preventing the noise induced hearing loss especially among young people. An experimental system designed for the continuous monitoring of the acoustic climate of urban areas was developed and implemented within the PLGrid Plus project. The assessment of environmental threats...
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Effects of La Content on the Densification, Microstructure, and Conductivity of Doped La10−x Ge6 O26±δ Electrolytes
PublikacjaIn this study, the influence of La content on the characteristics of Nb-, Mo-, and W-doped LaxGe6O26±δ electrolytes was investigated through sintering study, X-ray diffraction, scanning electron microscopy, and conductivity measurement. The densification of LaxGe5.5Nb0.5O26±δ and LaxGe5.5W0.5O26±δ was retarded as the x reached 9.75, while that of LaxGe5.5Mo0.5O26±δ improved with increasing La content. The average grain size slightly...
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Modification of Selected Propagation Models in Terms of Path Loss Estimation in Container Terminal
PublikacjaIt is particularly important to look for any propagation model that could be useful for designing mobile radio networks in container terminal environment. Selected propagation models have been investigated. Firstly - basing on measurements results - they have been evaluated in this scope and the analysis has shown, that the adjustment is needed. This modification improved significantly the accuracy of path loss modelling. For the...