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Wyniki wyszukiwania dla: wall pressure
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Numerical calculation wall pressure and stresses in cylindrical silos withconical hopper
PublikacjaOmówiono wyniki numerycznego obliczania naporu materiału sypkiego na ściany silosu. Obliczenia wykonano stosując metodę elementów skończonych i sprężysto idealnie plastyczne prawo konstytutywne według Druckera-Pragera. W analizie uwzględniono wpływ osiowy i mimośrodowy.
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Experimental investigation of the flow pattern and wall pressure distribution in a silo with double-cone insert
PublikacjaArtykuł opisuje przeprowadzone badania przepływów silosowych i naporu materiałów sypkich podczas napełniania i opróżniania silosu o średnicy 2.5 m wyposażonego we wkładkę "podwójny stożek". Badania przeprowadzane były w Instytucie Badawczym Tel-Tek w Norwegii. Materiałem użytym był suchy piasek. Napór na ścianę mierzony był bezpośrednio za pomocą 10 czujników wbudowanych w ścianę. Badania eksperymentalne pokazały duży wpływ wkładki...
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The influence of a cone-in-cone insert on flow pattern and wall pressure in a full-scale silo
PublikacjaArtykuł opisuje przeprowadzone badania przepływów silosowych i naporu materiałów sypkich podczas napełniania i opróżniania silosu o średnicy 2.5 m wyposażonego we wkładkę "stożek w stożku''. Badania przeprowadzane były w Instytucie Badawczym Tel-Tek w Norwegii. Materiałem użytym był suchy piasek. Napór na ścianę mierzony był bezpośrednio za pomocą 10 czujników wbudowanych w ścianę. Badania eksperymentalne pokazały duży wpływ wkładki...
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Evolution of shear localisation in earth pressure problems of a retaining wall
PublikacjaPrzedstawiono wyniki numerycznej analizy formacji stref ścinania w materiale sypkim podczas problemów parcia i odporu gruntu za ścianą oporową. Zachowanie suchego piasku podczas testów ściskania w płaskim stanie odkształcenia było analizowane stosując metodę elementów skończonych i mikropolarne hypoplastyczne prawo konstytutywne. Podczas obliczeń numerycznych zwrócono szczególną uwagę na wpływ różnych przemieszczeń ściany na lokalizację...
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Numerical calculations of wall pressures and stresses in steel cylindrical silos with concentric and eccentric hoppers
PublikacjaArtykuł przedstawia numeryczną analize naprężeń w płaszczu silosa. Porównane zostały wyniki dla silosów o przepływie centrycznym i mimośrodowym.
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Discrete simulations of shear zone patterning in sand in earth pressure problems of a retaining wall
PublikacjaW artykule przedstawiono wyniki doświadczalne i teoretyczne naporu piasku na ściankę szczelną. Obliczenia wykonano stosując metodę elementów dyskretnych. Wyniki porównano z wynikami uzyskanymi metodą elementów skończonych na bazie mikropolarnego hipoplastycznego prawa materiałowego oraz z wynikami doświadczalnymi uzyskanymi metodą korelacji obrazów cyfrowych. Wykonano obszerne studia parametryczne.
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A novel in vivo approach to assess strains of the human abdominal wall under known intraabdominal pressure
PublikacjaThe study concerns mechanical behaviour of a living human abdominal wall. A better mechanical understanding of a human abdominal wall and recognition of its material properties is required to find mechanically compatible surgical meshes to significantly improve the treatment of ventral hernias. A non-invasive methodology, based on in vivo optical measurements is proposed to determine strains of abdominal wall corresponding to...
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FE-anlysis of pattering of shear zones in granular bodies for earth pressure problems of a retaining wall.
PublikacjaW artykule przedstawiono wyniki numerycznej analizy stref ścinania w płaskim stanie odkształcenia dla materiałów granulowanych dla problemów parcia i odporu gruntu przy ścianie szczelnej. Obliczenia przeprowadzono z modelem hipoplastycznym rozszerzonym o długość charakterystyczną w ramach mechaniki Cossertów. Wyniki obliczeń porównano z wynikami doświadczeń.
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Wpływ geometrii i szorstkości ścian na wielkość naporu materiału sypkiego na dno silosu = Influence of geometry and wall roughness of silo wall on bottom vertical pressure
PublikacjaW pracy przedstwiono analizę wpływu wysokości i szorstkości ścian silosu cylindrycznego na rozkład naporu na ściany i dno. Badania przeprowadzono dla piasku bezkohezyjnego.
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Full-field in vivo experimental study of the strains of a breathing human abdominal wall with intra-abdominal pressure variation
PublikacjaThe presented study aims to assess the mechanical behaviour of the anterior abdominal wall based on an in vivo experiment on humans. Full-field measurement of abdominal wall displacement during changes of intra-abdominal pressure is performed using a digital image correlation (DIC) system. Continuous measurement in time enables the observation of changes in the strain field during breathing. The understanding of the mechanical...
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Full scale measurements of pressure field induced on the quay wall by bow thrusters – indirect method for seabed velocities monitoring
PublikacjaThe paper presents the results of full-scale experimental investigation of loads generated on the quay wall by bow thrusters during unberthing of a self-manoeuvring vessel. The presented research allowed for the comparison of the measurements results with generally accepted empirical prediction methods and confirmed the utility of the developed measuring setup for the on-line monitoring of jet induced loads. The conclusions from the...
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Relationship between heart rate variability, blood pressure and arterial wall properties during air and oxygen breathing in healthy subjects
PublikacjaPrevious studies reported that normobaric hyperoxia influences heart rate, arterial pressure, cardiac output and systemic vascular resistance, but the mechanisms underlying these changes are still not fully understood. Several factors are considered including degeneration of endothelium-derived nitric oxide by reactive oxygen species, the impact of oxygen-free radicals on tissues and alterations of autonomic nervous system function....
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Membrane model of human abdominal wall. Simulations vs. in vivo measurements
PublikacjaThe study presents a methodology of defining a numerical model of human abdominal wall based on the experimentally registered data of the abdomen geometry due to variations of the intraabdominal pressure. The abdominal wall is modelled here as a simple homogeneous membrane structure made of linear orthotropic material The displacements registered during the increase of pressure are compared with the re-sults of the model static...
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Determination of Earth Pressure and Displacement of the Retaining Structure According to the Eurocode 7-1
PublikacjaComparative analysis of standard guidelines and findings given in EC7-1 and in Polish Standard PN-83/B-03010. Discussed guidelines concerning active and passive earth pressure as well as at rest pressure state. Wall displacement causing limit states of earth pressure and resistance. Interactive assumptions concerning intermediate earth pressure and resistance values. Conclusions and final remarks.
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NUMERICAL SIMULATIONS OF HONING PROCESS OF THIN WALL CYLINDER LINERS, WITH CONSTANT AND WITH VARIABLE THICKNESS OF WALL OF HONED PARTS
PublikacjaNumerical simulations of honing process of thin-wall cylinder liners, with constant and with variable thickness of the wall of honed workpieces can improve and can help to conduct the experimental research of honing process and can improve the honing process. A very valuable research assumption, before performing the numerical analysis of computer simulation of honing process, is the measurement of the real geometry of the honing...
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Insights Into Hydrodynamics of Spinning Fluids Reactor
PublikacjaSpinning fluids reactor (SFR) is one of the most efficient gas-liquid contacting system with high potential of application in many fields. The unique solution of SFR is the contacting of two spinning fluids which generated centrifugal force. The aim of this study was to investigate the pressure field distribution on the inner surface of reactors dispersing element. Obtained results confirm the high heterogeneity of the field pressure...
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Isogeometric Shell FE Analysis of the Human Abdominal Wall
PublikacjaIn this paper a nonlinear isogeometric Kirchhoff-Love shell model of the human abdominal wall is proposed. Its geometry is based on in vivo measurements obtained from a polygon mesh that is transformed into a NURBS surface, and then used directly for the finite element analysis. The passive response of the abdominal wall model under uniform pressure is considered. A hyperelastic membrane model based on the Gasser-Ogden-Holzapfel...
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Global sensitivity analysis of membrane model of abdominal wall with surgical mesh
PublikacjaThe paper addresses the issue of ventral hernia repair. Finite Element simulations can be helpful in the optimization of hernia parameters. A membrane abdominal wall model is proposed in two variants: a healthy one and including hernia defect repaired by implant. The models include many uncertainties, e.g. due to variability of abdominal wall, intraabdominal pressure value etc. Measuring mechanical properties with high accuracy...
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The protocol for using elastic wall model in modeling blood flow within human artery
PublikacjaMedical diagnostic tools will play a major role in the future for an effective patient treatment and reduction their mortality, related to the cardiovascular system diseases (CVDs). There is an urgent need for developing diagnostic procedure to be robust, reliable, accurate and efficient, in the framework of a paradigm shift. Application of numerical techniques is seen as a perspective tool for such purpose. Nevertheless, existing...
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Material Identification of the Human Abdominal Wall Based On the Isogeometric Shell Model
PublikacjaThe human abdominal wall is an object of interest to the research community in the context of ventral hernia repair. Computer models require a priori knowledge of constitutive parameters in order to establish its mechanical response. In this work, the Finite Element Model Updating (FEMU) method is used to identify an heterogeneous shear modulus distribution for a human abdominal wall model, which is based on nonlinear isogeometric...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublikacjaA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublikacjaA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Novel strategies to enhance hydrodynamic cavitation in a circular venturi using RANS numerical simulations
PublikacjaHydrodynamic cavitation is a popular advanced oxidation technique and it has received wide range of applications from waste water treatment to the nanoparticles synthesis in recent years. The enhancement of the intensity of the hydrodynamic cavitation is always been an emerging field of research. Within this framework, we have proposed and investigated three distinct strategies to enhance the intensity of cavitation in a circular...
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Structured deformation of granular material in the state of active earth pressure
PublikacjaThe paper focuses on the ability of granular materials to undergo structured deformation by analysing the data from the retaining wall model tests and discrete element simulations. The structured deformation means the movement of a granular material which produces a stable, regular pattern of multiple shear bands. The paper's primary purpose is to study this kind of deformation for the selected data representing the state of active...
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Study of Non-Newtonian biomagnetic blood flow in a stenosed bifurcated artery having elastic walls
PublikacjaFluid structure interaction (FSI) gained attention of researchers and scientist due to its applications in science felds like biomedical engineering, mechanical engineering etc. One of the major application in FSI is to study elastic wall behavior of stenotic arteries. In this paper we discussed an incompressible Non-Newtonian blood fow analysis in an elastic bifurcated artery. A magnetic feld is applied along x direction. For...
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Posttraumatic Orbital Emphysema: A Numerical Model
PublikacjaOrbital emphysema is a common symptom accompanying orbital fracture. The pathomechanism is still not recognized and the usually assumed cause, elevated pressure in the upper airways connected with sneezing or coughing, does not always contribute to the occurrence of this type of fracture. Observations based on the finite model (simulating blowout type fracture) of the deformations of the inferior orbital wall after a strike in...
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Raz jeszcze o obciążeniu hydrodynamicznym falochronu pionowościennego falą stojącą
PublikacjaPrzedstawienie istniejących modeli matematycznych opisujących rozkłady ciśnienia hydrodynamicznego na falochron pionowościenny w wyniku oddziaływania fali stojącej. Analiza nieciągłości ciśnienia. Jakościowe porównanie metod obliczeniowych dla wybranych warunków wodno-falowych.
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Experimental and comparative study on the two-phase pressure drop of air-water mixture in U-bend and straight pipe annuli
PublikacjaIn this paper, the experimental and theoretical analysis of pressure drop in singlephase and two phase-flow were presented for straight and U-bend smooth tube annulus and tube annulus with wire coil insert. Experiments for various boundary conditions were performed. In case of U-tube and straight tube with and without turbulator, tests were made for the water-water and air-water systems. The study covered a wide measuring range,...
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Mechanics of mesh implanted into abdominal wall under repetitive load. Experimental and numerical study
PublikacjaThere are a number of papers discussing medical and mechanical aspects of ventral hernia management. Despite intensive work on the problem understanding, recurrences of the sickness still happen too often. For that reason new aspects of the problem must be considered. In this paper, a change in the abdominal implant’s stiffness is discussed, which is caused by cyclic loading. Such loading influence abdominal implant e.g. while...
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Biomechanical causes for failure of the Physiomesh/Securestrap system
PublikacjaThis study investigates the mechanical behavior of the Physiomesh/Securestrap system, a hernia repair system used for IPOM procedures associated with high failure rates. The study involved conducting mechanical experiments and numerical simulations to investigate the mechanical behavior of the Physiomesh/Securestrap system under pressure load. Uniaxial tension tests were conducted to determine the elasticity modulus of the Physiomesh...
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Analytical model with non-adiabatic effects for pressure drop and heat transfer during boiling and condensation flows in conventional channels and minichannels
PublikacjaIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for boiling flow and condensation flow with account of non- adiabatic effects for some recent data collected from literature. The first effect, the modification of interface shear stresses in annular flow pattern is considered through incorporation of the so called "blowing parameter". The mechanism of...
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Effect of Simultaneous Valve Closures in Hydraulic Piping Systems
PublikacjaThe paper investigates wave interference (between pressure waves) occurring in simple hydraulic systems. Water hammer was induced by simultaneous closure of three valves located at the reservoirs of a “Y” type hydraulic system. Numerical simulations were carried out with the help of the freeware computer package Allievi enabling the reader to replicate results in a direct manner. The influence of the following quantities has been...
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Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part I: Research Methodology and Results
PublikacjaThe technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate bottles, commonly called PET, are increasingly used in this technology. In this paper, the main aim is to describe the statistical analysis methodology of the influence of the temperature of the...
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Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part II: Statistical Analysis and Interpretation of Tests
PublikacjaThe technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, and vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate (PET) bottles are increasingly used in this technology. In this paper, the main aim is to describe and interpret the results of statistical analysis of the influence of the temperature of...
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Prediction of coking dynamics for wet coal charge
PublikacjaA one-dimensional transient mathematical model describing thermal and flow phenomena during coal coking in an oven chamber was studied in the paper. It also accounts for heat conduction in the ceramic oven wall when assuming a constant temperature at the heating channel side. The model was solved numerically using partly implicit methods for gas flow and heat transfer problems. The histories of temperature, gas evolution and internal...
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Fluid structure interaction study of non-Newtonian Casson fluid in a bifurcated channel having stenosis with elastic walls
PublikacjaFluid–structure interaction (FSI) gained a huge attention of scientists and researchers due to its applications in biomedical and mechanical engineering. One of the most important applications of FSI is to study the elastic wall behavior of stenotic arteries. Blood is the suspension of various cells characterized by shear thinning, yield stress, and viscoelastic qualities that can be assessed by using non-Newtonian models. In this...
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Comparative Analysis of Numerical and Experimental Studies of the Airflow Around the Sample of Urban Development
PublikacjaIn this paper, on the background of a short overview of the recent advances in the field of Environmental Wind Engineering (EWE), a comparison of wind tunnel experiment and numerical simulation for some cases of airflow around an urban layout have been reported. The purpose of the study is quantitative and qualitative comparison of measurements in the wind tunnel as well as numerical simulation using Ansys Fluent software. The...
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SIMULATION OF PROCEED® SURGICAL MESH APPLIED TO VENTRAL HERNIA REPAIR
PublikacjaIn the present research, Proceed® implant is considered. The system is subjected to short-time dynamic pressure load, similar to post-operative cough naturally occurring in human abdomen. The model refers to a clinical case of 5cm of hernia operated by Proceed implant fixed by 15 joints every 3cm around the orifice. The simulations of the implanted mesh are performed by means of the Finite Element Method. The implant is modelled...
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The importance of individual spray properties in performance improvement of a urea-SCR system employing flash-boiling injection
PublikacjaThe appropriate mixing of a urea–water solution (UWS) with exhaust gases in a selective catalytic reduction system is crucial to efficiently reduce nitrogen oxides and diminish the deposition of liquid wall film. One of the methods to enhance the mixing of the UWS with the exhaust gases is a flash-boiling injection. Its positive effect has been linked with a reduced Sauter mean diameter (SMD) and improved evaporation, but the...
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Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application
PublikacjaThe more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model...
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BLADDER, Bladder wall, NOS - Male, 3 - Tissue image [7040247104956091]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Male, 3 - Tissue image [5280730021697221]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Male, 3 - Tissue image [5280730021705581]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Male, 3 - Tissue image [5280730021702881]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Male, 3 - Tissue image [5280730021704451]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Male, 3 - Tissue image [5280730021704071]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Female, 0 - Tissue image [4130730018865911]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Male, 3 - Tissue image [5280730021706721]
Dane BadawczeThis is the histopathological image of BLADDER 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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BLADDER, Bladder wall, NOS - Female, 55 - Tissue image [9140730014141581]
Dane BadawczeThis is the histopathological image of BLADDER 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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Thermal and economic investigation of straight and U-bend double tube heat exchanger with coiled wire turbulator
PublikacjaExperimental research has been carried out for four individual heat exchanger constructions, i.e., plain double tube, turbulized double tube, plain U-bend and U-bend with turbulator. Tests were made for the water-water system. The study covered a wide measuring range, i.e., Re = 800–9000 – on the shell side, for a constant cold water temperature of 9 ◦C and hot water of 50 ◦C. The heat exchangers were made from copper tubes with...