Filters
total: 2767
-
Catalog
displaying 1000 best results Help
Search results for: local impedance imaging
-
Evaluation of Temperature Influence on Electrochemical Processes Occurring in a Lithium-Ion Supercapacitor with the Use of Dynamic Electrochemical Impedance Spectroscopy
PublicationIn order to obtain the full impedance characteristics of a lithium-ion capacitor as a function of temperature, the authors proposed the use of dynamic electrochemical impedance spectroscopy. Impedance tests were carried out under wide range of dynamic temperature changes for lithium-ion supercapacitors. Significant differences in electrochemical processes were observed as a result of working temperature. Moreover, the quality of...
-
Evaluation of applicability of classic methods of a fault loop impedance measurement to circuits with residual current devices
PublicationMeasurement of fault loop impedance in low voltage grids and systems is in most cases performed to verify the effectiveness of protection against electric shock by automatic disconnection of supply. For the sake of measurement accuracy, it is advisable to perform it using large current. Unfortunately, in circuits with residual current devices which are very widely used nowadays, a large measurement current may trigger those devices...
-
Multi-objective optimization of compact UWB impedance matching transformers using Pareto front exploration and adjoint sensitivities
PublicationIn this paper, a technique for fast multi-objective optimization of impedance matching transformers has been presented. In our approach, a set of alternative designs that represent the best possible trade-offs between conflicting objectives (here, the maximum reflection level within a frequency band of interest and the circuit size) is identified by directly exploring the Pareto front. More specifically, the subsequent Pareto-optimal...
-
New Method of Non-Linear Electrochemical Impedance Spectroscopy with an Amplitude-Modulated Perturbation Signal
PublicationThe paper presents a new method of non-linear electrochemical impedance spectroscopy (NLEIS), which allows fast and nondestructive evaluation of the corrosion rate and determination of the Tafel coefficients values for a corrosion system under investigation. This method employs amplitude modulation of the ac perturbation signal. The study demonstrated that it was possible to obtain impedance characteristic as a function of the...
-
Method of reconstructing two-dimensional velocity fields on the basis of temperature field values measured with a thermal imaging camera
PublicationThis paper describes a novel numerical reconstruction procedure (NRP) of the velocity field during natural convective heat transfer from a two-sided, isothermal, heated vertical plate based only on the known temperature field obtained, e.g. with a thermal imaging camera. It has been demonstrated that with a knowledge of temperature distributions, the NRP enables the reconstruction of velocity fields by solving the Navier-Stokes...
-
Electrical and mechanical characterization of two-phase alloys by means of scanning probe microscopy in dynamic impedance spectroscopy mode
PublicationDynamic impedance spectroscopy, evaluated for measuring non-stationary systems, was used in combination with scanning probe microscope. Using this approach, localized impedance measurements in the AFM contact mode could be carried out. Additionally, impedance–force curves were made at each phase of investigated materials to illustrate the relation between impedance and the force applied to a probe. Therefore, correlation of electrical...
-
Monitoring of breast tissue thermo-ablation by means of impedance measurements
PublicationW pracy przedstawiono rozważania dotyczące monitorowania jakości termoablacji zmian nowotworowych w piersi przy pomocy pomiarów impedancyjnych. Pokazano prototypowe konstrukcje sond do termoablacji jak również zaprezentowano wyniki symulacji i pierwszych eksperymentów. A usefulness of a developed probe combining power delivery to ablated breast tumour and simultaneous impedance measurements is discussed in the paper. It consists...
-
Reply to Comment on ‘Nanodiamond incorporated human liver mimicking phantoms: prospective calibration medium of magnetic resonance imaging’
PublicationDependence of the spin–lattice (T1) relaxation times on the nanodiamond concentration in human liver phantoms is discussed. Factors affecting stability and and reproducibility of these phantoms are presented. The need for comparative measurements on multiple MRI scanners for better understanding of potential variations in the obtained imaging data is emphasised.
-
Journal of Medical Imaging and Health Informatics
Journals -
The loop impedance measurement
Open Research DataThe loop impedance measurement
-
Recent advances in gaseous imaging photomultipliers
Publication -
The DICOM standard for medical thermal imaging
PublicationW pracy przedstawiono propozycję schematu danych dla potrzeb ujęcia jej w międzynarodowej normie DICOM. Schemat danych oraz oprogramowanie referencyjne przygotowane dla potrzeb aplikacji termografii w medycynie.
-
Thermal imaging and modelling of burned skin
PublicationW artykule przedstawiono wyniki eksperymentów in-vivo na zwierzętach w diagnostyce oparzeń z wykorzystaniem metod obrazowania termicznego w podczerwieni. Wyniki skorelowano z rezultatami otrzymanymi w symulacjach numerycznych tkanki skóry.
-
Applications of image registration in parametric imaging
PublicationArtykuł przedstawia możliwości poprawy jakości obrazów parametrycznych przez eliminacje artefaktów ruchowych w sekwencji obrazów. Zaprezentowano multimodalne wizualizacje obrazów oraz przedstawiono wyniki dopasowania różnych obrazów MRI do siebie.
-
Applications of image registration in parametric imaging
PublicationArtykuł przedstawia wyniki badań z zakresu wykorzystania metod nakładania obrazów w obrazowaniu parametrycznym. Podstawowe zastosowania obejmują korekcję artefaktów ruchowych oraz wizualizację obrazu multimodalnego.
-
IMAGING OF PROTON BRAGG PEAKS IN LiF
Publication -
Distributed processing in medical, parametric imaging
PublicationArtykuł prezentuje metodę dystrybucji bazującej na JavaSpace do zastosowania w wyznaczaniu obrazów parametrycznych. Zaimplementowano metodologię Compute Server, którą użyto do aktywnej termografii i dynamicznych badań MRI mózgu.
-
Thermal Imaging in Wound Healing Diagnostics
PublicationOpisano wyniki projektu badawczego poświęconego opracowaniu metody obiektywnej diagnostyki ran pooperacyjnych w kardiochirurgii. Sprawdzono możliwość połączenia oceny obrazów RGB z obrazami termograficznymi oraz nową w medycynie metodą aktywnej termografii dynamicznej ADT. W projekcie zastosowano chłodzenie obszaru zainteresowania wykorzystując kriostat na dwutlenku węgla. W okresie powrotu do stanu równowagi termodynamicznej rejestrowane...
-
Thermal Imaging in Wound Healing Diagnostics
PublicationResults of a project searching for objective, quantitative evaluation of postoperative wound healing in cardiosurgery are presented. We propose simple thermal models of the healing processes after cardiosurgery interventions as objective descriptors allowing classification of patients for extraction and following recovery at home or for prolonged treatment in a hospital. Classification of healing as the normal process or as a process...
-
Determination of time delay between ventricles contraction using impedance measurements
PublicationThe paper presents a novel approach to assessment of ventricular dyssynchrony basing on multichannel electrical impedance measurements. Using a proper placement of electrodes, the sensitivity approach allows estimating time difference between chambers contraction from over determined nonlinear system of equations. The theoretical considerations which include Finite Element Method simulations were verified using measurements on...
-
Dynamic impedance measurements of the Direct Methanol Fuel Cell cathode at various operating temperatures
PublicationThis 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...
-
Influence of the local building tradition on Renaissance architecture in Royal Prussia
PublicationContrary to the southern Europe the first signs of Renaissance in northern parts of the Holy Roman Empire as well as in Poland and Lithuania might be observed only at the beginning of the 16th century. Initially, they were created by Italian teams which came from Florence, Rome and the region of Como. One of the most recognizable marks of that process was the transfer of the Italian craftsmen and architectural solutions, e.g....
-
The influence of dynamic load changes on temporary impedance in hydrogen fuel cells, selection and validation of the electrical equivalent circuit
PublicationTo achieve optimal performance of a fuel cell, a reliable monitoring and diagnostic method is required. The currently utilized methods give limited information or they are impossible to use under dynamic working conditions. To obtain comprehensive information about the fuel cell operation we utilized novel dynamic electrochemical impedance spectroscopy. Impedance measurements in dynamic mode were performed on a hydrogen fuel cell,...
-
Multi-Fidelity Local Surrogate Model for Computationally Efficient Microwave Component Design Optimization
PublicationIn order to minimize the number of evaluations of high-fidelity (“fine”) model in the optimization process, to increase the optimization speed, and to improve optimal solution accuracy, a robust and computational-efficient multi-fidelity local surrogate-model optimization method is proposed. Based on the principle of response surface approximation, the proposed method exploits the multi-fidelity coarse models and polynomial interpolation...
-
In vivo imaging of the human eye using a two-photon excited fluorescence scanning laser ophthalmoscope
PublicationBACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans...
-
Local mesh morphing technique for parametrized macromodels in the finite element method
PublicationThis paper presents a novel approach for enhancing the efficiency of the design process of microwave devices by means of the finite element method. It combines mesh morphing with local model order reduction (MOR) and yields parametrized macromodels that can be used to significantly reduce the number of variables in the FEM system of equations and acceleration of computer simulation. A projection basis for local reduction is generated...
-
Interpolation methods in GPR tomographic imaging of linear and volume anomalies for cultural heritage diagnostics
PublicationThis paper presents results of a ground penetrating radar (GPR) survey conducted in St. Joseph’s Church in Gdańsk, Poland. The aim of the study was to produce tomographic imaging of a renovated floor as well as the objects buried under the floor to detect linear and volume inclusions. The assumed track spacing was meaningfully greater than the single signal spacing in each track, which induced the need for interpolation methods...
-
Speed management on local government managed roads – research, recommendations and guidelines
PublicationCommissioned by the National Road Safety Council Secretariat, the project “Guidelines for speed management on local government managed roads” studied car driver be haviour when subjected to selected speed management measures such a local speed restrictions, surveillance, traffic calming and restricted speed areas. In addition, analyses were conducted on the impact of selected me asures...
-
Electrochemical properties of porous Sr0.86Ti0.65Fe0.35O3 oxygen electrodes in solid oxide cells: Impedance study of symmetrical electrodes
PublicationThis work evaluates porous Sr0.86Ti0.65Fe0.35O3 (STF35) as a possible oxygen electrode material for Solid Oxide Cells. The powder synthesis was performed by solid state method. Characterization included DC electrical conductivity study of sintered bulk samples and impedance spectroscopy study of symmetrical electrodes deposited on gadolinium doped ceria substrates. Measurements were carried out in atmospheres with different pO2...
-
From Advice and Consultation to Local Co-governance. The Case of Advisory Councils in Polish Cities
Publication -
Rapid multi-objective design optimization of miniaturized impedance transformer by Pareto front exploration
PublicationFast multi-objective optimization of compact impedance transformer is discussed. A set of alternative designs representing possible trade-offs between conflicting design criteria, i.e., electrical performance (here, wideband matching) and the structure size, is obtained through Pareto front exploration by means of surrogate-assisted methods.
-
EMI mitigation of GaN power inverter leg by local shielding techniques
PublicationThis paper presents local shielding techniques applied to a half-bridge inverter leg with the aim to reduce the common mode (CM) current noise at converter’s DC input. The research study is conducted for 650V Enhancement mode Gallium Nitride (GaN) power transistor switches. Main contributors of parasitic capacitances referred to the inverter-leg middle point node are identified. Then, shielding solutions are proposed to reduce...
-
Ellipse-fitting algorithm implementation in the impedance measurement system based on DAQ card with FPGA
PublicationThe paper presents an implementation of the ellipse-fitting algorithm in the impedance measurement system based on DAQ card equipped with FPGA chip. The method implementation was tested by simulation means as well as experimentally in the designed and presented measurement system. Finally, the limit values of sampling parameters which assures satisfying accuracy were given.
-
General Provisioning Strategy for Local Specialized Cloud Computing Environments
PublicationThe well-known management strategies in cloud computing based on SLA requirements are considered. A deterministic parallel provisioning algorithm has been prepared and used to show its behavior for three different requirements: load balancing, consolidation, and fault tolerance. The impact of these strategies on the total execution time of different sets of services is analyzed for randomly chosen sets of data. This makes it possible...
-
Determination of pitting corrosion stage of stainless steel by galvanodynamic impedance spectroscopy
PublicationThis paper investigates the methodology for differentiation of multistep process of pitting corrosion of AISI 304 stainless steel in the environment of iron (III) chloride. Measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Application of this methodology allowed monitoring of natural corrosion process without external current (IDC = 0A) nor potential perturbation of the system. Applied...
-
The use of thermal imaging camera to estimate velocity profiles based on temperature distribution in a free convection boundary layer
PublicationThis work describes an attempt to assess whether the temperature field from a thermal imaging camera can be converted into a velocity field with an accuracy sufficient for qualitative conducting or describing the phenomenon, i.e. when the Navier-Stokes, Fourier-Kirchhoff and continuity equations are mutually coupled. The consequence of this link between temperature fields and velocity is the possibility to formulate the hypothesis...
-
A strategy for GPS data processing in a precise local network during high solar activity
PublicationThis paper presents the analyses connected with reduction of errors from ionospheric refraction using GPS data from local satellite networks. This is particularly essential during rising solar activity. The Bernese GPS Software v. 4.2 was used, as an analytical tool. The test data included measurements from a geodynamic network SUDETES situated in the Sudety Mountains across the border between the Czech Republic and Poland. A local...
-
Local Mesh Deformation for accelerated parametric studies based on the Finite Element Method
PublicationThis paper presents an approach for enhancing the efficiency of two-dimensional Finite Element Method analysis in parametric studies or optimisation process of microwave components. The new approach involves local mesh deformation applied near the elements that are modified during computations. Since in the proposed approach the topology of the mesh remains unchanged, a new mesh does not have to be generated from scratch when the...
-
Local variance factors in deformation analysis of non-homogenous monitoring networks
PublicationThis paper proposes a modification of the classical deformation analysis algorithm for non-homogeneous (e.g. linear-angular) monitoring networks. The basis for the proposed solution is the idea of local variance factors. The theoretical discussion was complemented with an example of its application on a simulated horizontal monitoring network. The obtained results confirm the usefulness of the proposed solution.
-
Local Texture Pattern Selection for Efficient Face Recognition and Tracking
PublicationThis paper describes the research aimed at finding the optimal configuration of the face recognition algorithm based on local texture descriptors (binary and ternary patterns). Since the identification module was supposed to be a part of the face tracking system developed for interactive wearable computer, proper feature selection, allowing for real-time operation, became particularly important. Our experiments showed that it is...
-
Linear and nonlinear impedance in iron oxide glasses containing alkaline ions and alkali free
PublicationThe linear and nonlinear impedance spectra of oxide glasses were measured in the frequency range of 1 mHz to 1 MHz and in the temperature range of 153K to 483K. Two groups of iron oxide glass samples were prepared, the first one containing alkaline ions and the second one without alkali. In the first group, compositions of glasses were as follows: (in %mol) 50% SiO2 , 25% PbO, 15% Fe2O3 and 15% one of alkaline oxides: Na2O, K2O,...
-
Differential analysis of impedance data
Publication -
The amplitude analysis of impedance spectra
Publication -
Measuring the impedance of ultrasonic transducers.
PublicationW przypadku przetworników ultradźwiękowych charakteryzujących się zazwyczaj bardzo zmienną w funkcji częstotliwości impedancją jej pomiar stwarza szereg trudności. Nie nadają się do tego celu tanie, łatwo dostępne, przyrządy. Znane są drogie systemy badawcze stosowane do tego celu. Zazwyczaj przystosowane są one do takich pomiarów w szerokim paśmie częstotliwości, od pasma akustycznego aż do zakresu mikrofalowego. Natomiast,...
-
Correction methods in impedance spectroscopy
PublicationW pracy przedstawiono trzy grupy metod, ktÓre mogą być zastosowane do korekcji danych pomiarowych uzyskanych za pomoca spektroskopii impedancyjnej.
-
Design of a modular impedance tomography
PublicationW pracy przedstawiono konstrukcję, zasadę działania oraz podstawowe parametry tomografu impedancyjnedo przeznaczonego do pomiarów w gruncie.
-
Impedance of metastable pitting corrosion
PublicationPrzeprowadzono badania impedancyjne metastabilnego procesu korozji wżerowej. Kształt chwilowych widm impedancyjnych otrzymanych w wyniku eksperymentu jest ściśle związany z przebiegiem prądu dc. O szybkość korozji wewnątrz aktywnego zaatakowania decyduje proces przeniesienia ładunku. Ekspansja aktywnej powierzchni jest proporcjonalna do zmian podwójnej warstwy elektrycznej. Zaobserwowane zostały również zmiany rezystancji elektrolitu...
-
An integral-differential method for impedance determination of the hydrogen oxidation process in the presence of carbon monoxide in the proton exchange membrane fuel cell
PublicationThe impedance of a proton exchange membrane fuel cell powered by hydrogen contaminated with carbon monoxide, ranging from 150 to 300 ppb, is measured and discussed. The tested range of CO concentration complied with the fuel standard specified in the ISO standards. Studies of influence of CO contamination on operation of PEMFC are crucial for further development and commercialization of fuel cells for automotive applications. Based...
-
A method of earth fault loop impedance measurement without unwanted tripping of RCDs
PublicationIn low-voltage networks, earth fault loop impedance (EFLI) measurement is the basis for assessing the effectiveness of automatic disconnection of supply. Such a measurement is performed during initial and periodical verification, especially in a TN low-voltage network. Nowadays, due to widespread application of residual current devices (RCDs), such test is difficult in many circuits because RCDs operate during the test. In this...
-
The impedance of hydrogen oxidation reaction in a proton exchange membrane fuel cell in the presence of carbon monoxide in hydrogen stream
PublicationEvaluation of performance of a proton exchange membrane fuel cell, which is affected by carbon monoxide that pollutes the hydrogen stream, was presented. This influence was studied for carbon monoxide concentration of 125–325 ppb, which are close to values specified in ISO 14687:2019 standard. Performed studies provided crucial information for further development of fuel cell as an energy source for automotive application. Impedance...
-
Positive solutions to Sturm–Liouville problems with non-local boundary conditions
PublicationIn this paper, the existence of at least three non-negative solutions to non-local boundary-value problems for second-order differential equations with deviating arguments α and ζ is investigated. Sufficient conditions, which guarantee the existence of positive solutions, are obtained using the Avery–Peterson theorem. We discuss our problem for both advanced and delayed arguments. An example is added to illustrate the results.
-
The role of urban movements in the process of local spatial planning and the development of participation mechanism
PublicationIn civil societies, urban movements are one of the tools in the process of spatial governance. In Poland, urban activism is beginning to develop together with a budding participation in public life. Therefore, there is a need to assess the scope and effects of the urban movements’ actions. The aim of the study was to determine and evaluate their impact on the spatial development in three Polish cities - Poznań, Gdańsk and Gdynia, especially...
-
Fluorescence Imaging Using Methylene Blue Sentinel Lymph Node Biopsy in Melanoma
PublicationIntroduction: Fluorescence imaging of sentinel node biopsy in melanoma is a novel method. Both indocyanine green (ICG) and methylene blue (MB) have fl uorescent properties. The aim of this study was to present, for the fi rst time in a clinical series of patients, the possible usage of MB as a fl uorescent dye for sentinel node biopsy during surgery for melanoma. Material and methods: Twenty patients with...
-
Computer -Aided Local Energy Planning Using ALEP-PL Software
PublicationThe issue of energy system planning, including the planning of local energy systems, is critical, since it affects the security of energy supplies in communities, regions, and consequently the security of energy supply within the country. Energy planning is a complex process that requires integration of different goals i.e. improvement of energy efficiency, increase in the share of renewables in the energy balance and CO2} emission...
-
Assessing the Significance of Displacements Using Local Coefficients of Variance as an Alternative to the Classical Approach
PublicationThe safety of use of civil engineering structures remains an important issue that is approached by various sciences. Due to this fact, geodetic control measurements are conducted with the purpose of identifying threats connected with the potential displacement of structural elements. In this context, the authors discuss issues connected with determining the displacements of controlled points located in the studied object in a three-dimensional...
-
Local buckling of thin-walled channel member flange made of aluminum alloy
PublicationThe paper deals with local stability of the thin-walled compressed flange of channel columns and beams made of aluminum alloy. The aim of paper is to find critical stress of local buckling of the flange member taking into account the web-flange interaction in linear and nonlinear elastic range of the member material. The governing differential equation of the problem is derived with aid of the principle of stationary total potential...
-
Reconstruction of 3D structure of positive corona streamer by local methods
PublicationThe computer algorithms were used for reconstruction of streamer 3D structure. We propose the 3D tree structure model of corona discharge streamer composed with nodes and edges between chosen couples of nodes, which enables easy computation of some important parameters ofstreamers. The 3D model can be derived directly from two projection images by global methods like evolutionary searching or particle simulations. In this paper...
-
Intelligent thermal imaging camera with network interface
Publication -
Validity of MRI brain perfusion imaging method
PublicationW artykule zaprezentowano zbiór analiz dotyczących walidacji metody DSC-MRI. Zbadano wpływ rozmycia, opóźnienia, niskiego SNR bolusa oraz innych możliwych źródeł zakłócających wartość parametru perfuzji. Różne metody uzyskiwania parametrów perfuzji zostały zaprezentowane i porównane.
-
Validity of MRI brain perfusion imaging method
PublicationW artykule zaprezentowano zbiór analiz dotyczących walidacji metody DSC-MRI. Zbadano wpływ rozmycia, opóźnienia, niskiego SNR bolusa oraz innych możliwych źródeł zakłócających wartość parametru perfuzji. Różne metody uzyskiwania parametrów perfuzji zostały zaprezentowane i porównane.
-
Motion analysis and classification with motion history imaging
Publication -
Effect of underwater local cavity welding method conditions on diffusible hydrogen content in deposited metal
PublicationOne of the methods with great potential for applications in underwater repairs is local cavity welding. In local cavity method, cooling conditions and diffusible hydrogen amount in weld metal are nearly the same as those existed during welding in the air. This paper presents the results of literature survey and preliminary tests of the effect of local cavity welding conditions on diffusible hydrogen amount in a deposited metal....
-
Nonlinear and linear impedance of bismuth vanadate ceramics and its relation to structural properties
PublicationThe nonlinear and linear electrical properties, topography, and microstructure of bismuth-vanadate ceramics, were studied. The structurewas observed with the use of X-ray diffraction (XRD), scanning electronmicroscopy (SEM), atomic force microscopy (AFM) and confocal microscopy methods. The obtained results showed that ceramic is porous. Two phase transitionswere determinedwith the use of DSC measurements. The linear and nonlinear ac...
-
Bead-on-plate welding on S235JR steel by underwater local dry chamber process
PublicationThe article presents the results of the effect of parameters of underwater local dry chamber welding on the properties of padding welds. The effect of heat input and the type of shielding gas on the structure and hardness of welds was established. the functions for estimating the maximum hardness of the heat affected zone have been also elaborated.
-
The application of environmental issues in designing urban structures – a framework for comprehensive local planning policies
PublicationThe implementation of environmental issues in planning and designing urban structures is becoming a novel approach and a common practice consistent with the paradigm of sustainable development. Maintaining environmental quality in urban areas, managing natural resources and understanding the complexity of urban systems is becoming increasingly challenging. Therefore, it is important to develop strategies for the integration of...
-
Local material symmetry group for first- and second-order strain gradient fluids
PublicationUsing an unified approach based on the local material symmetry group introduced for general first- and second-order strain gradient elastic media, we analyze the constitutive equations of strain gradient fluids. For the strain gradient medium there exists a strain energy density dependent on first- and higher-order gradients of placement vector, whereas for fluids a strain energy depends on a current mass density and its gradients....
-
On the space of equivariant local maps
Publication -
Local Monitoring of EGNOS Services
PublicationW artukule przedstawiono wyniki lokalnego monitoringu dostępności serwisów satelitarnego systemu nawigacyjnego EGNOS.
-
Local-Global Space Mapping for Rapid EM-Driven Design of Compact RF Structures
PublicationIn this work, we introduce a robust and efficient technique for rapid design of compact RF circuits. Our approach exploits two-level space mapping (SM) correction of an equivalent circuit model of the structure under design. The first SM layer (local correction) is utilized to ensure good matching between the equivalent circuit and the electromagnetic model at the component level. On the other hand, the global correction allows...
-
Local Dye Concentration and Spectroscopic Properties of Monomer−Aggregate Systems in Hybrid Porous Nanolayers
PublicationAnalysis of absorption, fluorescence, and time-resolved emission spectra of rhodamine 6G in hybrid porous nanolayers at high dye concentration allowed identification of two fluorescent species: monomers and fluorescent aggregates. The method of determination of mean local concentration of aggregates in matrices is proposed based on the energy transfer process between monomers and fluorescent aggregates. Evaluation of aggregate...
-
Does source matter? Generation of investment expenditures by different types of local government revenues
PublicationThe purpose of the article was to investigate the impact of the three fundamental statutory categories of budget revenues, i.e. own revenues, general subsidies and specific grants on the size of investments made by local government units in Poland. The subject scope included the local government subsector in its entirety, as well as divided into 4 groups: communes (gminas), cities with powiat rights, districts (powiats) and province...
-
ATTEMPTS OF THERMAL IMAGING CAMERA USAGE IN ESTIMATIONS OF THE CONVECTIVE HEAT LOSS FROM A VERTICAL PLATE
PublicationIn this paper a new method for determining heat transfer coefficients using a gradient method has been developed. To verify accuracy of the proposed method vertical isothermal heating plate with natural convection mechanism has been examined. This configuration was deliberately chosen, because of the fact that such case is historically the earliest and most thoroughly studied and its rich scientific documentation - the most reliable....
-
The impact of air humidity on the operation of proton exchange membrane fuel cells determined using dynamic electrochemical impedance spectroscopy
PublicationThis 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...
-
99mTc-Galacto-RGD2: A Novel 99mTc-Labeled Cyclic RGD Peptide Dimer Useful for Tumor Imaging
PublicationThis study sought to evaluate [99mTc(HYNIC-Galacto-RGD2)-(tricine)(TPPTS)] (99mTc-Galacto-RGD2: HYNIC = 6-hydrazinonicotinyl; Galacto-RGD2 = Glu[cyclo[Arg-Gly-Asp-D-Phe-Lys(SAA-PEG2-(1,2,3-triazole)-1-yl-4-ethylamide)]]2 (SAA = 7-amino-L-glycero-L-galacto-2,6-anhydro-7-eoxyheptanamide, and PEG2 = 3,6-dioxaoctanoic acid); and TPPTS = trisodium triphenylphosphine-3,3',3''-trisulfonate) as a new radiotracer for tumor imaging. Galacto-RGD2...
-
Identification of the mechanical properties of the skin by electromechanical impedance analysis of resonant piezoelectric actuator
PublicationThis paper is devoted to the analysis and verification of developed piezoelectric sensor/actuator for measuring the mechanical properties of soft tissues, especially human skin. The key element of the measurement structure is an electromechanical system that uses both the reverse piezoelectric effect (vibration generation – stimulation of the tissues in the appropriate frequency range) and direct piezoelectric effect (system response...
-
Investigation of the electrochemical behaviour of AA1050 aluminium alloy in aqueous alkaline solutions using Dynamic Electrochemical Impedance Spectroscopy
PublicationThe paper presents the electrochemical behaviour of aluminium alloy AA1050 in aqueous alkaline media in the pH range 14–8.5. Electrochemical study was applied in order to obtain comprehensive information on the mechanism and kinetics of the process of anodic dissolution of aluminium, supplemented by monitoring of surface topography using an electron microscope. The corrosion rate of AA1050 increases with increasing concentration...
-
A novel method of local chirp-rate estimation of LFM chirp signals in the time-frequency domain
PublicationIn the paper, novel dynamic representations of a complex signal in the time-frequency domain are introduced. The proposed approach is based on using the gradient of the short-time Fourier transform complex phase. A channelized instantaneous complex frequency (CICF) and a complex local group delay (CLGD) are included in the presented signal representations. An application of the newly-introduced distributions is demonstrated by...
-
Trawl-Door Shape Optimization with 3D CFD Models and Local Surrogates
PublicationDesign and optimization of trawl-doors are key factors in minimizing the fuel consumption of fishing vessels. This paper discusses optimization of the trawl-door shapes using high-fidelity 3D computational fluid dynamic (CFD) models. The accurate 3D CFD models are computationally expensive and, therefore, the direct use of traditional optimization algorithms, which often require a large number of evaluations, may be prohibitive....
-
International Journal of Regional and Local History
Journals -
Dynamic Electrochemical Impedance Spectroscopy (DEIS) as a Tool for Analyzing Surface Oxidation Processes on Boron-Doped Diamond Electrodes
PublicationSurface oxidation processes play a key role in understanding electrochemical properties of boron-doped diamond (BDD) electrodes. The type of surface termination groups, which create the potential window of electrolytic water stability or hydrophobicity, influences such properties. In this study the kinetics of oxidation process under anodic polarization were studied in situ by means of Dynamic Electrochemical Impedance Spectroscopy...
-
Underwater in situ local heat treatment by additional stitches for improving the weldability of steel
PublicationIn this paper the influence of in situ local heat treatment performed by additional stitches on the weldability of high-strength low-alloy (HSLA) S355J2C+N steel was tested. The investigated steel is characterized by high susceptibility to cold cracking. It is necessary to find a method to improve the quality of welded joints. The local heat treatment was applied as an eect of bead-on plate welding made on the face of a Tekken...
-
Application of galvanodynamic impedance spectroscopy for studying passive film cracking under mechanical strain
PublicationThe paper reports the results of simultaneous mechanical and electrochemical investigations on austenitic (18/8) stainless steel in a 2 % solution of sulphuric acid. The measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Electrochemical analysis of mechanical passive layer cracking and repassivation conditions during a tensile test was carried out. Application of this methodology allowed...
-
Possibility of thermal imaging use in studies of natural convection heat transfer on the example of an isothermal vertical plate.
PublicationA new method of infrared (IR) camera use in convective heat transfer studies has been presented. Until now, IR cameras were utilized for temperature field visualizations of flat heated surfaces of solid objects only. Because liquids and gasses do not emit radiation in the infrared range of wave lengths, detection of temperature field in the air was conducted with the use of plastic mesh, which, after heating by hot air, emits infrared...
-
Electrochemical cell impedance spectra at Eoc
Open Research DataThe dataset presents impedance spectrum of electrochemical cell filled with 3% NaCl solution presented in the figure below. This cell was used measured using Atlas-Sollich 0531 impedance analyser with built-in potentiostat. When changing the DC polarisation of the cell the non-linear phenomena could be observed. The impedance spectrum frequency range...
-
Impedance monitoring of fuel cell stacks
Publication -
Analyzer for spectroscopy of low-impedance objects
PublicationW artykule przedstawiono analizator umożliwiający pomiar impedancji w zakresie 1 ohma < |Zx| < 100 Mohma. Zastosowano w nim nowe rozwiązania dotyczące obwodu wejściowego i techniki detekcji fazoczułej sygnałów pomiarowych. Obwód wejściowy zaprojektowano w postaci 5-zaciskowej sondy pomiarowej, która umożliwia ograniczenie wpływu rezystancji, indukcyjności i pojemności pasożytniczych na błąd pomiaru impedancji w szerokim przedziale...
-
Impedance spectroscopy of undoped cerium oxide.
PublicationW pracy przedstawiono badania impedancyjne niedomieszkowanego tlenku ceru. Wyniki wskazują na występowanie zjawiska dyfuzji,???? które nie są (.. jest.?)związane z odpowiedzią elektrodową. Rozważania teoretyczne dopuszczają obserwowanie impedancji Warburga, która reprezentuje zjawisko dyfuzji w przewodnikach mieszanych, jednakże niewiele informacji na ten temat można znaleźć w literaturze. W związku z tym szczegółowe badania zródła...
-
Impedance spectroscopy of single chamber SOFC.
PublicationMechanizm działania jednokomorowego ogniwa paliwowego SOFC, które pracuje w mieszaninie powietrza i paliwa, nie jest do końca zbadany. W tej pracy przedstawiono wyniki badań ogniwa paliwowego zbudowanego z tlenku cyrkonu stabilizowanego itrem jako nośnego elektrolitu, cermetu z tlenku niklu jako anody i perovskitu LSCF jako katody w temperaturach 500-700C z użyciem mieszaniny propanu i powietrza. Wykorzystując spektroskopię impedancyjną...
-
Property revenues (PRs) and expenditures of local government units (LGUs) in Poland
PublicationPRs are new category of local government revenues, which was introduced by changing the law on public finances at the end of 2006 and which took effect in 2007. By principle, these revenues should be converted into property expenditures. Their formalisation did not only allow assessing their absolute size but also a comparison with the longer existing property expenditures. Both categories were subject of analysis in this article....
-
Determination of causes of accelerated local corrosion of austenitic steels in water supply systems
PublicationThis paper concerns an inspection of a water supply system, made of AISI 304 steel, which showed signs of local corrosion at the weld. Such corrosion caused material perforation after very short periods of operation. It was revealed that steel was sensitised during the welding process. It was also proven that chromium micro-segregation occurred in the alloy leading to galvanic cell formation which initialised the process of pitting...
-
FE investigations of the effect of fluctuating local tensile strength on coupled energetic-statistical size effect in concrete beams
PublicationThe effect of fluctuating local tensile strength on a coupled energetic-statistical size effect in plain concrete beams under bending was numerically investigated. First, the influence of varying autocorrelation length of the random field describing a spatial variation of local tensile strength was studied. Next, the influence of the coefficient of variation of local tensile strength was analyzed. The numerical FE investigations...
-
Selected local stability problems of channel section flanges made of aluminium alloys
PublicationThe paper addresses the issue of local buckling of compressed flanges of cold-formed thin-walled channel columns and beams with nonstandard flanges composed of aluminium alloys. The material behaviour follows the Ramberg–Osgood law. It should be noted that the proposed solution may be also applied for other materials, for example: stainless steel, carbon steel. The paper is motivated by an increasing interest in nonstandard cold-formed...
-
A CMOS Pixel With Embedded ADC, Digital CDS and Gain Correction Capability for Massively Parallel Imaging Array
PublicationIn the paper, a CMOS pixel has been proposed for imaging arrays with massively parallel image acquisition and simultaneous compensation of dark signal nonuniformity (DSNU) as well as photoresponse nonuniformity (PRNU). In our solution the pixel contains all necessary functional blocks: a photosensor and an analog-to-digital converter (ADC) with built-in correlated double sampling (CDS) integrated together. It is implemented in...
-
Local Structure and Stability of SEI in Graphite and ZFO Electrodes Probed by As K-edge Absorption Spectroscopy
PublicationThe evolution of the solid electrolyte interphase (SEI) during the first Li uptake in advanced Li-ion electrodes is studied by X-ray absorption spectroscopy (XAS). The As atoms present in the electrolyte solution were used as a local probe for monitoring the SEI growth on different electrodes. High-quality As K-edge spectra were collected in fluorescence mode for a set of graphite and carbon-coated ZnFe2O4 electrodes. XAS measurements...
-
Local atomic order in low Pt-content nanocatalysts investigated in situ by XAS
PublicationThe unique features of X-ray absorption spectroscopy allow investigations of nanosized catalysts for fuel cells under working conditions. We present the results of an experiment carried out on a low Pt content electrocatalyst supported by a mesoporous heteropolyacid salt and used at the cathode of a proton exchange membrane fuel cell (PEMFC). The analysis of the EXAFS signal at the Pt L3-edge indicates that upon operating the fuel...
-
Galvanostatic impedance measurements for the efficient adsorption isotherm construction in corrosion inhibitor studies
PublicationWe present an approach towards an accurate and time-efficient adsorption isotherm determination to evaluate the corrosion inhibitor interaction in electrolytic environments. The approach is based on dynamic impedance spectroscopy measurements in galvanostatic mode (g-DEIS). The studied corrosion inhibitor is continuously injected between the secondary cell and the corrosion cell. The efficiency corresponding to instantaneous inhibitor...
-
The electrochemical impedance spectroscopy studies of the anode material based on polymer and starch derived ceramic for lithium ion batteries
PublicationThe anode materials derived of preceramic polymer poly(1,2-dimethylsilazane) (PSN) and starch was study. Commercially available polysilazane (poly(1,2-dimethylsilazane (PSN 2M01 Gelest) was mixed with commercially available starch (POCH Gliwice). The ratio polymer/starch (PSN/starch) was 1/1 or 3/7. The polysialazane/starch blend was cross-linked at 230 ºC for 2 h followed by heating to the final temperature (500 ºC, 700 ºC and...
-
Determination of t8/5 cooling times for underwater local dry welding of steel
PublicationKnowledge of thermal history is the basic condition for studying the structure - properties of welded joints. The determinant of thermal history is the thermal cycle, whose in-situ measurements are still a big challenge. Water as the welding environment complicates this issue even more. The article presents a method to determine an equation for calculating t8/5 cooling times for underwater gas metal arc welding of unalloyed steels...
-
In Vitro and In Vivo Imaging-Based Evaluation of Doxorubicin Anticancer Treatment in Combination with the Herbal Medicine Black Cohosh
PublicationAs a substitution for hormone replacement therapy, many breast cancer patients use black cohosh (BC) extracts in combination with doxorubicin (DOX)-based chemotherapy. In this study, we evaluated the viability and survival of BC- and DOX-treated MCF-7 cells. A preclinical model of MCF-7 xenografts was used to determine the influence of BC and DOX administration on tumor growth and metabolism. The number of apoptotic cells after...
-
Quantitative study of free convective heat losses from thermodynamic partitions using Thermal Imaging
PublicationThe following paper presents a simple method of determining the presence, distribution and values of heat losses from external building walls as thermodynamic partitions using a Thermal Imaging Camera (TIC). According to Fourier's equation, the value of heat loss is proportional to the temperature gradient ∂t/∂y|y=0 in air in the y direction perpendicular to the heated surface. Unfortunately, air temperature cannot be measured...