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Degradation of ferritic X10CrAlSi18 stainless steel caused by slurry
PublikacjaThe slurry erosion tests of ferritic X10CrAlSi18 steel were carried out using a slurry pot device. In order to investigate the erosion process, two series of tests were performed: first one with a constant impact velocity of 5 m/s, 7 m/s and 9 m/s and the second one, during which the impact velocity was changed after every exposure. During each test, an influence of test conditions on volume loss, surface hardness and roughness...
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Recent advances in traffic optimisation: systematic literature review of modern models, methods and algorithms
PublikacjaOver the past few decades, the increasing number of vehicles and imperfect road traffic management have been sources of congestion in cities and reasons for deteriorating health of its inhabitants. With the help of computer simulations, transport engineers optimise and improve the capacity of city streets. However, with an enormous number of possible simulation types, it is difficult to grasp valuable, innovative solutions which...
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Hyperbolic heat conduction at a microscopic sliding contact with account of adhesion-deformational heat generation and wear
PublikacjaDifferent non-Fourier models were proposed to simulate temperatures in materials subjected to extremely fast thermal disturbances, when the speed of heat propagation should be concerned. The present study investigated temperature and heat balance at a microscopic sliding contact during a single frictional interaction based on the Cattaneo-Vernotte hyperbolic heat conduction equation. Two fundamental features of friction, namely,...
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A structure and design of a novel compact UWB MIMO antenna
PublikacjaIn the paper, a concept and design procedure of a novel compact MIMO slot antenna is presented. In order to achieve a better filling of available space, individual antennas are constrained to a triangular shape and optimized for a reduced size. The MIMO structure is then assembled using the two of previously designed antennas in orthogonal arrangement. Surrogate-assisted numerical optimization involving variable-fidelity electromagnetic...
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Porous material-based sorbent coatings in Solid-phase microextraction technique: Recent trends and future perspectives
PublikacjaThe use of porous materials as sorbents in sample preparation techniques has gained recent scientific attention in the context of developing novel fibers for the Solid-phase microextraction (SPME) technique. SPME requires the appropriate selection of a robust sorbent for successful utilization under variable conditions. A deeper understanding of the nature of newly developed porous SPME coatings and the impact of their structures...
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Heterogeneous distribution of surface electrochemical activity in polycrystalline highly boron-doped diamond electrodes under deep anodic polarization
PublikacjaThe surface homogeneity of boron-doped diamond electrodes is variable and depends on anodic polarization conditions. The differentiation factor is the gradual and localized change in surface termination. A series of measurements under different polarization conditions was performed in order to investigate the scale of this effect. Nanoscale impedance microscopy (NIM) revealed large variation of surface resistance in individual...
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The Influence of the Radio Channel on Precision of Position Estimation of the User Terminal Using the NB-IoT Radio Interface
PublikacjaIn the article the method of user terminal position estimation using the broadcast signals transmitted in the downlink of the NB-IoT interface was presented, including the analysis of the radio channel influence on precision of position estimation as well as the eNodeB (Evolved Node B) synchronization. The practical ability to estimate the position in the test area has been verified in the laboratory conditions, using the reference...
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Communication and Load Balancing Optimization for Finite Element Electromagnetic Simulations Using Multi-GPU Workstation
PublikacjaThis paper considers a method for accelerating finite-element simulations of electromagnetic problems on a workstation using graphics processing units (GPUs). The focus is on finite-element formulations using higher order elements and tetrahedral meshes that lead to sparse matrices too large to be dealt with on a typical workstation using direct methods. We discuss the problem of rapid matrix generation and assembly, as well as...
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Analiza czynników wpływających na prędkość pojazdów transportu zbiorowego na przykładzie Gdańska
PublikacjaW referacie przedstawiono istotę problemu szacowania prędkości pojazdów transportu zbiorowego w szczególności w zakresie modelowania ruchu. Przedstawiono i omówiono wyniki przeprowadzonych w maju ubiegłego roku pomiarów czasu przejazdu pojazdów transportu zbiorowego na obszarze Gdańska w ramach budowy systemu sterowania ruchem TRISTAR. Otrzymane wyniki zestawiono w celu zaprezentowania statystyki oraz zidentyfikowania czynników...
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BENEFITS FROM BREAKING UP WITH LINUX NATIVE PACKET PROCESSING WHILE USING INTEL DPDK LIBRARIES
PublikacjaThe Intel Data Plane Development Kit (DPDK) is a set of libraries and drivers for fast packet processing in Linux. It is a dedicated framework for building efficient high-speed data plane applications supporting QoS features with poll mode drivers which are supporting virtual and physical NIC’s so environment can be used to build efficient data plane applications for packet networks. The results of test on Quality of Service Metering...
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Entrepreneurial Business and Economic Review
PublikacjaThe objective of the article is to explore internationalisation patterns of family high-tech firms, especially their internationalisation motives, intensity, speed, and entry modes. The empirical part adopts a quantitative approach. The results of the survey are presented on the sample of 263 high-tech production firms from Poland, including 101 family firms. The survey was conducted in all 16 Polish regions. The calculations from...
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Internationalization patterns of Polish family high-tech firms
PublikacjaThe objective of the article is to explore internationalisation patterns of family high-tech firms, especially their internationalisation motives, intensity, speed, and entry modes. The empirical part adopts a quantitative approach. The results of the survey are presented on the sample of 263 high-tech production firms from Poland, including 101 family firms. The survey was conducted in all 16 Polish regions. The calculations from...
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The Suzuki model of the multipath fading channel
Dane BadawczeThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The Suzuki fading envelope is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
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The shallow sea experiment with usage of linear hydrophone array
PublikacjaPurpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects...
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The influence of feed rate and shear forces on the devulcanization process of ground tire rubber (GTR) conducted in a co-rotating twin screw extruder
PublikacjaThe search for new ways to recycling of rubber waste has been the aim of many studies conducted by research centers and companiesworldwide. The results of our investigations on the process of continuous thermomechanical devulcanization of ground tire rubber using a twin screw extruder are presented.We used a co-rotating twin screw extruder with a special configuration of plasticizing unit, enabling generation of considerable shear...
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Analysing the impact of traffic incidents on express road traffic flow using FREEVAL
PublikacjaTraffic incidents occurring on motorways or express roads cause disruptions and deteriorate traffic conditions. The impact will differ depending on the type of incident, its duration and space blocked on the roadway and can be measured with e.g. average speed reduction, extension of travel time, time lost or overall costs of traffic disruptions. The aim of the paper is to analyse this impact, based on data from the Tri-City Ring...
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Use of response surface methodology in characterization of properties of recycled high density polyethylene/ground tire rubber compositions
PublikacjaSearching for newways to utilize rubber and polymerwaste has been the focus of many studies conducted by research centers and companies worldwide. In this study, the influence of extrusion conditions on the properties of thermoplastic compositions containing post-production recycled high density polyethylene (PE-HD) and ground tire rubber (GTR) at 50:50 mass ratiowas examined. Response Surface Methodology (RSM) was used to determine...
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Nonlinear properties of the Gotland Deep – Baltic Sea
PublikacjaThe properties of the nonlinear phenomenon in water, including sea water, have been well known for many decades. The feature of the non homogeneous distribution of the speed of sound along the depth of the sea is very interesting from the physical and technical point of view. It is important especially in the observation of underwater area by means of acoustical method ( Grelowska et al ., 2013; 2014). The observation of the underwater...
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In-tube extraction for the determination of the main volatile compounds in Physalis peruviana L
PublikacjaAn analytical procedure based on in-tube extraction followed by gas chromatography with mass spectrometry has been developed for the analysis of 24 main volatile components in cape gooseberry (Physalis peruviana L.) samples. According to their chemical structure, the compounds were organized into different groups: one hydrocarbon, one aldehyde, four alcohols, four esters, and 14 monoterpenes. By single-factor experiments, incubation...
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Effect of Tool Positioning Factors on the Strength of Dissimilar Friction Stir Welded Joints of AA7075-T6 and AA6061-T6
PublikacjaFriction Stir Welding (FSW) is a solid-state bonding technique. There are many direct and indirect factors affecting the mechanical and microstructural properties of the FSW joints. Tool offset, tilt angle, and plunge depth are determinative tool positioning in the FSW process. Investigating the effect of these factors simultaneously with other parameters such as process speeds (rotational speed and translational speed) and tool...
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DETERMINATION OF THE AERODYNAMIC DRAG OF PNEUMATIC LIFE RAFTS AS A FACTOR FOR INCREASING THE RELIABILITY OF RESCUE OPERATIONS
PublikacjaEnsuring the safety of ship crews at sea is of the utmost importance. Life rafts are one of the basic components of any seagoing vessel and ensuring their stability is an important component of maritime research. This study concerns the determination of the aerodynamic drag coefficients of pneumatic life rafts in a full range of wind speed and directions. The drag coefficients are based on full-scale experimental studies and numerical...
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Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych
PublikacjaIn this paper a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid) has been presented. A conception of a dual-stator hybrid exciter has been proposed. Comparison study of classical and hybrid exciter has been carried out. For the electromagnetic calculation two approaches have been applied: an analytical approach (based...
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The use of Preston equation to determine material removal during lap-grinding with electroplated CBN tools
PublikacjaGrinding executed in a lapping configuration is an alternative finishing process benefiting from both grinding and free-abrasive machining, while minimizing the heat effect impact. Electroplated tools can be effectively used in different abrasive processes, including high-speed grinding, however, the assessment of machining performance over time is a key factor in their correct use to achieve satisfactory technological results....
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Position and velocity measurement using incremental encoder and microcontroller.
PublikacjaThere is presented measurement of position and velocity using Atmel's microcontroller ATTiny2313 with 20 MHz clock and encoder with 1024 pulses per revolution. This configuration allows measuring maximum speed 48800 rpm with 1x accuracy, 20200 rpm with 2x accuracy and 9400 rpm with 4x accuracy (quadrature). Position is measured with resolution of 0.352', 0.176' and 0.088' for 1x, 2x, 4x accuracy respectively. Algorithms of position...
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Guitar String Sound Retrieved from Moving Pixels
PublikacjaThe aim of this study was to develop a method of visual recording and analyzing the vibrations of guitar strings using high-speed cameras and dedicated video processing algorithms. The recording of a plucked string reveals the way in which the deformations propagate, composing the standing and travelling wave. The paper compares the results for a few selected models of classical and acoustic guitars, and it involves processing...
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Towards an efficient multi-stage Riemann solver for nuclear physics simulations
PublikacjaRelativistic numerical hydrodynamics is an important tool in high energy nuclear science. However, such simulations are extremely demanding in terms of computing power. This paper focuses on improving the speed of solving the Riemann problem with the MUSTA-FORCE algorithm by employing the CUDA parallel programming model. We also propose a new approach to 3D finite difference algorithms, which employ a GPU that uses surface memory....
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Zero-Pole Space Mapping for CAD of Filters
PublikacjaIn this paper, we propose a new space-mapping technique tailored to the CAD of microwave filters. The goal of space mapping is to achieve a satisfactory design with the minimal number of fine model evaluations. In our approach, the filter is represented by a rational function. To quickly align the coarse and fine models, and to speed up the direct optimization of the coarse model, we propose matching the zeros and poles of a rational...
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Comparison of active proximity radars for the wearable devices
PublikacjaTwo methods of object position and movement estimation in relation to the user of smart glasses were investigated. An active infrared and ultrasonic methods of the obstacle detection were presented and compared. Application of these methods depend on active transducers type (physical medium used), geometry and surface properties of detected objects and their movement direction and speed. In the article properties of both detectors...
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Sensitivity analysis of simple random beam models by means of Monte Carlo Methods using Variance Reductions Techniques
PublikacjaA probabilistic sensitivity analysis of two nonlinear bar structures is presented. The analysis is carried out on the basis of the Monte Carlo method. The imperfections of the structures and the applied loads are adapted as random variables. Based on all of the generated input variables, an output response of the system is sought. Afterwards, a coefficient responsible for the structure failure is calculated and the limit state...
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Regression points in non-intrusive polynomial chaos expansion method and D-optimal design
PublikacjaThe 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...
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Tunable Dielectric Switching of (Quinuclidinium)[MnCl4] Hybrid Compounds
PublikacjaInorganic−organic hybrid QMnCl (Q = quinuclidinium) crystals were synthesized and characterized. The X-ray and variable-temperature IR/Raman analysis demonstrate that the crystals undergo a reversible structural phase transition, which originates from an order−disorder process and is related to the dynamics of the organic Q cation. Dielectric function measurements disclose a switchability between low (“OFF”) and high (“ON”) dielectric...
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Diagnosis of bearing damage in induction motors by instantaneous power analysis
PublikacjaResearch of the machine with simulated bearing damages has been carried out, where variable load torque, simulating bearing damage, was introduced. The results show that components which can be used for bearings diagnosis appear in the spectrum of the product of current and supply voltage instantaneous values. These components are easier to identify than the components of current spectrum, which have been used so far in diagnostic...
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Sensitivity analysis of critical loads of I-columns
PublikacjaThe first order variation of critical buckling load of thin-walled columns with bisymmetric open cross-section due to some variations of the design variables such as: cross-section dimensions, or material characteristics is derived. The influence of the residual welding stresses is taken into account. In the numerical examples dealing with I-column the functions describing the effect of the variation of the dimensions of the flange...
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Radionuclides activity and effective doses referred to geological formations
PublikacjaNaturally occurring radioactive materials (NORM) are present in Earth’s crust and they caused natural background radiation, variable in different regions. Liquid, gas and solid radionuclides emit three types of radiation – alpha, beta and gamma. Fluctuations of natural radioactivity in different geological formations in the world and in Poland were compared in relation to radiological hazard. Also drilling cuttings from boreholes...
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Elimination of impulsive disturbances from stereo audio recordings
PublikacjaThis paper presents a new approach to elimination of impulsive disturbances from stereo audio recordings. The proposed solution is based on vector autoregressive modeling of audio signals. On-line tracking of signal model parameters is performed using the stability-preserving Whittle-Wiggins-Robinson algorithm with exponential data weighting. Detection of noise pulses and model-based interpolation of the irrevocably distorted samples...
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Adaptive Method of Raster Images Compression and Examples of Its Applications in the Transport Telematic Systems
PublikacjaThe paper presents a concept and exemplary application of an adaptive method of compression of raster images which may be applied, i.a. in ITS systems. The described method allows to improve the efficiency of systems belonging to ITS category, which require transmission of large volumes of image data through telecommunications networks. The concept of the adaptive method of compression of raster images described in the paper uses...
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Charles Odeh dr
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Robert Dobieglewski
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Wpływ zmian dopuszczalnych wartości parametrów geometrycznych i kinematycznych na podatność modernizacyjną układów torowych
PublikacjaPodatnością modernizacyjną nazywamy stopień przystosowania analizowanego odcinka linii kolejowej do zmiany prędkości eksploatacyjnej. Skala możliwych zmian prędkości (w sensie jej zwiększenia) jest wypadkową istniejącego układu geometrycznego linii w planie, ograniczeń lokalizacyjnych oraz dopuszczalnych wartości parametrów geometrycznych i inematycznych. Jakiekolwiek zmiany tych ostatnich wpływają bezpośrednio na obliczenie elementarnych...
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Reducing Monitoring Costs in Industrially Contaminated Rivers: Cluster and Regression Analysis Approach
PublikacjaMonitoring contamination in river water is an expensive procedure, particularly for developing countries where pollution is a significant problem. This study was conducted to provide a pollution monitoring strategy that reduces the cost of laboratory analysis. The new monitoring strategy was designed as a result of cluster and regression analysis on field data collected from an industrially influenced river. Pollution sources in...
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Fast Low-fidelity Wing Aerodynamics Model for Surrogate-Based Shape Optimization
PublikacjaVariable-fidelity optimization (VFO) can be efficient in terms of the computational cost when compared with traditional approaches, such as gradient-based methods with adjoint sensitivity information. In variable-fidelity methods, the directoptimization of the expensive high-fidelity model is replaced by iterative re-optimization of a physics-based surrogate model, which is constructed from a corrected low-fidelity model. The success...
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Enhancing rheological muscle models with stochastic processes
PublikacjaPurpose: Biological musculoskeletal systems operate under variable conditions. Muscle stiffness, activation signals, and loads change during each movement. The presence of noise and different harmonic components in force production significantly influences the behaviour of the muscular system. Therefore, it is essential to consider these factors in numerical simulations. Methods: This study aims to develop a rheological mathematical...
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Nondestructive global corrosion measurement using guided wavefield data
PublikacjaMetallic structures often face degradation, and corrosion ranks among the most prevalent forms of deterioration. Accurate quantification of corrosion is crucial, especially for structures exposed to harsh environmental conditions, such as marine vessels and offshore installations. Because the traditional measurement methods based on scanning by ultrasonic gauge are time-consuming and provide only rough information on the thickness...
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Impact of Climate Change on Water Sources and River‐Floodplain Mixing in the Natural Wetland Floodplain of Biebrza River
PublikacjaThe origins of river and floodplain waters (groundwater, rainfall, and snowmelt) and their extent during overbank flow events strongly impact ecological processes such as denitrification and vegetation development. However, the long-term sensitivity of floodplain water signatures to climate change remains elusive. We examined how the integrated hydrological model HydroGeoSphere and the Hydraulic Mixing-Cell method could help us...
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Large cell neuroendocrine carcinoma - Female, 67 - Tissue image [12060630017622491]
Dane BadawczeThis is the histopathological image of BRONCHUS AND LUNG tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Nontoxic multinodular goitre - Female, 66 - Tissue image [7110729594547851]
Dane BadawczeThis is the histopathological image of THYROID GLAND tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Nontoxic multinodular goitre - Female, 66 - Tissue image [7110729594544291]
Dane BadawczeThis is the histopathological image of THYROID GLAND tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Large cell neuroendocrine carcinoma - Female, 67 - Tissue image [12060630017638311]
Dane BadawczeThis is the histopathological image of BRONCHUS AND LUNG tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Nontoxic multinodular goitre - Female, 66 - Tissue image [7110729594543271]
Dane BadawczeThis is the histopathological image of THYROID GLAND tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Nontoxic multinodular goitre - Female, 66 - Tissue image [7110729594544111]
Dane BadawczeThis is the histopathological image of THYROID GLAND tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.