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Search results for: pandemic threat
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Clinical studies of detecting COVID-19 from exhaled breath with electronic nose
PublicationThe COVID‑19 pandemic has attracted numerous research studies because of its impact on society and the economy. The pandemic has led to progress in the development of diagnostic methods, utilizing the polymerase chain reaction (PCR) as the gold standard for coronavirus SARS‑CoV‑2 detection. Numerous tests can be used at home within 15 min or so but of with lower accuracy than PCR. There is still a need for point‑of‑care tests available...
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Acoustics - new services for urban planning, research and education
PublicationThe main purpose of the presented design is twofold, namely: providing detailed information about the noise threats that occur every day in city areas and preventing the noise induced hearing loss especially among young people. An experimental system designed for the continuous monitoring of the acoustic climate of urban areas was developed and implemented within the PLGrid Plus project. The assessment of environmental threats...
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Facilitating free travel in the Schengen area—A position paper by the European Association for Biometrics
PublicationDue to migration, terror-threats and the viral pandemic, various EU member states have re-established internal border control or even closed their borders. European Association for Biometrics (EAB), a non-profit organisation, solicited the views of its members on ways which biometric technologies and services may be used to help with re-establishing open borders within the Schengen area while at the same time mitigating any adverse...
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How can Systems Thinking Help Us Handling the COVID-19 Crisis?
PublicationPurpose: COVID-19 pandemic outbreak remains one of the most influential events in the global economy over the recent years. While being primarily public health-related, it has a tremendous impact on many other aspects, such as public transport, education, and business management. Many businesses were forced to introduce rapid changes to their business models in order to survive. The aim of this paper is to show the complexity and...
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Comparitive study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels
PublicationIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation...
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Influence of nanoparticle concentration on convective heat transfer of water-Al2O3 nanofluids inside horizontal tubes
PublicationNanofluids came to be seen as a new generation of coolants, especially in single-phase systems. Conducted experiments indicate that the increase in thermal conductivity is not the only reason for the intensification of heat transfer when using nanofluids. Preliminary results of the experimental investigation of the forced convection heat transfer of water-Al2O3 nanofluids inside stainless steel tube with 8 mm internal diameter...
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Two-phase optimizing approach to design assessments of long distance heat transportation for CHP systems
PublicationCogeneration or Combined Heat and Power (CHP) for power plants is a method of putting to use waste heat which would be otherwise released to the environment. This allows the increase in thermodynamic efficiency of the plant and can be a source of environmental friendly heat for District Heating (DH). In the paper CHP for Nuclear Power Plant (NPP) is analyzed with the focus on heat transportation. A method for effectivity and feasibility...
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Neural network simulator's application to reference performance determination of turbine blading in the heat-flow diagnostics.
PublicationIn the paper, the possibility of application of artificial neural networks to perform the fluid flow calculations through both damaged and undamaged turbine blading was investigated. Preliminary results are presented and show the potentiality of further development of the method for the purpose of heat-flow diagnostics.
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Designate CTOD Heat Affected Zone of butt weld, Report No: WOiO/II/76/2013
PublicationTypical (normative) testing of materials and/or welded joints do not answer on all questions about material or welded joint properties. In ship building and off-shore sectors, many strucures requires materials and joint with higher than typical fatigue resistance. Imact tests, which are carried out during welding technology qualification, gives answer about ductility, CTOD tests results about material or welded joint ability...
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ORF Approximation in Numerical Analysis of Fractional Point Kinetics and Heat Exchange Model of Nuclear Reactor
PublicationThis paper presents results concerning numerical solutions of the fractional point kinetics (FPK) and heat exchange (HE) model for a nuclear reactor. The model consists of a nonlinear system of fractional and ordinary differential equations. Two methods to solve the model are compared. The first one applies Oustaloup Recursive Filter (ORF) and the second one applies Refined Oustaloup Recursive Filter (RORF). Simulation tests have...
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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....
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Corrosion-erosion damage of heat exchanger tubes by desalted crude oil flowing at shell side
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High Temperature Air/Steam Conversion of Biomass and Wastes Into Fuel Gas for Heat and Electricity Production
PublicationPaper present principle of high temperature air/staem gasification as well as some results of research using this technology for conversion of biomass and wastes into fuel gas.
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Heat transfer to car engine cooling system - influence of coolant flow through engine block
PublicationW artykule przedstawiono wyniki badań doświadczalnych nad wpływem nastawianej wydajności pompy cieczy na strumień odbieranego ciepła w silniku spalinowym. Wykorzystano hamownię silnikową z silnikiem o zapłonie iskrowym o objętości skokowej 1.8 dm^3. Przyjęto obciążenia silnika oporami ruchu samochodu na biegu bezpośrednim.
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A new method for determination of flow boiling heat transfer coefficient in conventional diameter channels and minichannels
PublicationW pracy przedstawiono rozważania związane z modelowaniem wrzenia w przepływie w kanałach o średnicach konwencjonalnych, małych i minikanałach. Przedstawiono przegląd podejść do modelowania wymiany ciepła i w tym świetle przedstawiono oryginalne podejście autora. W przeciwieństwie do innych podejść metoda autora ma zastosowanie zarówno do kanałów o średnicach konwencjonalnych i minikanałach. Przedstawiono zadowalające porównania...
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A semi-empirical method for calculation of heat transfer coefficient in flow boiling for conventional tubes and minichannels
PublicationW pracy przedstawiono zagadnienia które należy uwzględnić podczas modelowania wymiany ciepła z wrzeniem w przepływie w kanałach o małej średnicy. Uzyskano dobrą zgodność z wynikami badań eksperymentalnych.
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ORF Approximation in Numerical Analysis of Fractional Point Kinetics and Heat Exchange Model of Nuclear Reactor
PublicationThis paper presents results concerning numerical solutions of the fractional point kinetics (FPK) and heat exchange (HE) model for a nuclear reactor. The model consists of a nonlinear system of fractional and ordinary differential equations. Two methods to solve the model are compared. The first one applies Oustaloup Recursive Filter (ORF) and the second one applies Refined Oustaloup Recursive Filter (RORF). Simulation tests have...
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Influence of nanoparticle concentration on convective heat transfer of water-Al2O3 nanofluids inside horizontal tubes
PublicationThis work presents preliminary results of the experimental investigation of the forced convection heat transfer of water-Al2O3 nanofluids inside stainless steel tube with 8 mm internal diameter and 2000 mm length. Nanoparticles were tested at the concentrations of 0.01%, 0.1%, 1% and 5% by weight and the Reynolds number range encompasses laminar as well as turbulent flows.
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Implementation of Fluidized Bed Concept to Improve Heat Transfer in Ecological Adsorption Cooling and Desalination Systems
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Towards enhanced heat and mass exchange in adsorption systems: The role of AutoML and fluidized bed innovations
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Organic Rankine cycle turbogenerator cooling – Optimization of the generator water jacket heat exchange surface
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Capillary pumped loop as a tool for collecting large heat fluxes from electronic devices on warships
PublicationThe combat potential of future warships will be directly related to the use of modern electronic devices being parts of advanced systems, such as, for instance, radar systems, fire aiming systems, fire detection systems, electric drive systems, and even electronic and radio-electronic weaponry, railguns and lasers, installed on these warships. The capacity and functionality of these devices is continually increasing, at decreasing...
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Technical Aspects and Energy Effects of Waste Heat Recovery from District Heating Boiler Slag
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Experimental and numerical simulations of flow and heat transfer in heatexchanger elements using liquid crystal thermography.
PublicationPrzedstawienie koncepcji badań eksperymentalnych i numerycznych oraz ich wyników podczas wymiany ciepła w modelach klasycznych i płytowych wymienników ciepła w warunków przepływów przejściowych i turbulentnych.
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Influence of wall temperature on heat transfer coefficient during R 22 boiling in microfin tube
PublicationPrzedstawiono wyniki badań współczynnika przejmowania ciepła i spadku ciśnienia podczas wrzenia czynnika R 22 w rurze nisko żebrowanej. Opisano stanowisko i procedurę badawczą. Zaobserwowano spadek współczynnika przejmowania. Opisano stanowisko i procedurę badawczą. Zaobserwowano spadek współczynnika przejmowania ciepła wraz ze wzrostem temperatury ścianki rury.
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Corrosion-erosion damage of heat exchanger tubes by desalted crude oil flowing at shell side.
PublicationRurki wymiennika zostały uszkodzone lokalnie przez odsoloną ropę naftową przepływającą pod ciśnieniem 2,6 MPa i w temperaturze 385-395K. Większość powierzchni rurek nie była uszkodzona i była pokryta osadem związków organicznych i nieorganicznych, zabezpieczającym przed uszkodzeniami. Badania wykluczyły możliwość występowania intensywnej korozji elektrochemicznej na powierzchniach rurek pozbawionych osadu. Przyczyną perforacji...
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On the theory and numerical simulation of acoustic and heat modes interaction in a liquid with bubbles: acoustic quasi-solitons
PublicationTeoria rzutowania zaburzenia ogólnego na mody. Zastosowanie metody do badań układu równań typu Korteweg`a-de Vries`a. Rozwiązania analityczne i simulacje numeryczne.
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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...
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EXPERIMENTAL VERIFICATION OF THE METHOD OF FLOW BOILING AND FLOW CONDENSATION HEAT TRANSFER PREDICTION FOR SELECTED FLUIDS
PublicationIn the paper presented are the results of calculations using authors own model to predict heat transfer coefficient during flow boiling of different refrigerants. The experimental data from various research studies from literature were collected. Calculations were conducted for a full range of quality variation and a wide range of mass velocity. The aim of the study was to test the sensitivity of the in- house developed model....
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High-quality Experiment Dedicated to microGravity Exploration, Heat Flow and Oscillation Measurement from Gdańsk
PublicationIn this paper we propose HEDGEHOG (High-quality Experiment Dedicated to microGravity Exploration, Heat flow and Oscillation measurement from Gdańsk) REXUS experiment to investigate vibrational and heat flow phenomena during the whole (ascent, microgravity phase, descent and recovery) flight of a sounding rocket. First, a proposed system of cantilever beams is discussed to study dynamic behaviour of dummy payload. Dimensioning has...
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Heat treatment effect on Eu3+ doped TeO2-BaO-Bi2O3 glass systems with Ag nanoparticles.
PublicationGlass systems of 73TeO2-4BaO-3Bi2O3-2Eu2O3-xAg ( in molar ratio where x= 0, 1, 2, 3) compositions have been successfully synthesized. Silver nanoparticles were obtained with the employment of heat treatment (HT) procedure executed at 350 °C. Glass transition temperatures of different compositions have been determined through DSC measurements. XRD measurement results presented characteristic amorphous halo indicating lack of long...
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Small Scale Gasification of Biomass and Municipal Wastes for Heat and Electricity Production using HTAG Technology
PublicationCombustion and gasification technology utilizing high-cycle regenerative air/steam preheater has drawn increased attention in many application areas. The process is to be realized at temperature level above ash melting point using highly preheated agent. The use of highly preheated media above 900degC provides additional energy to conversion processes and results in considerable...
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Channel Blockage and Flow Maldistribution during Unsteady Flow in a Model Microchannel Plate heat Exchanger
PublicationThis paper describes the problem of channel blockage as a result of flow maldistribution between the channels of a model mini channel plate heat exchanger consisting of one pass on each leg. Each leg of the heat exchanger contains 51 parallel and rectangular minichannels of four hydraulic diameters namely 461 μm, 571 μm, 750 μm and 823 μm. In addition, a more complex geometry has been investigated where for the sake of breaking...
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Effect of asymmetric fluid flow distribution on flow boiling in a microchannel heat sink – An experimental investigation
PublicationFlow boiling in microchannels is emerging as an exclusive cooling solution for miniaturized high-power electronic devices alongside having other high heat flux applications. Size miniaturization at microscale strangely increases heat transfer performance as well as flow boiling instabilities. Many flow boiling instabilities are interrelated and result from imperfect hydrodynamic conditions. One of such problems is flow maldistribution among...
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Monitoring Regenerative Heat Exchanger in Steam Power Plant by Making Use of the Recurrent Neural Network
PublicationArtificial Intelligence algorithms are being increasingly used in industrial applications. Their important function is to support operation of diagnostic systems. This paper pesents a new approach to the monitoring of a regenerative heat exchanger in a steam power plant, which is based on a specific use of the Recurrent Neural Network (RNN). The proposed approach was tested using real data. This approach can be easily adapted to...
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A semi-empirical method for calculation of heat transfer coefficient in flow boiling for conventional tubes and minichannels
PublicationW pracy przedstawiono zagadnienia któe należy uwzględnić podczas modelowania wymiany ciepła z wrzeniem w przepływie w kanałach o małej średnicy. Uzyskano dobrą zgodność z wynikami badań eksperymentalnych.
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The importance of trust and altruistic social orientation for COVID-19 distress
PublicationBackground: The COVID-19 pandemic, the biggest global health crisis in decades, has been a difficult experience for nations all over the world. In the present study we wanted to assess to what extent a positive attitude towards others, expressed in altruistic social orientation and a high level of trust, would be linked to lower levels of COVID-19 distress in infected and non-infected individuals. Participants and procedure:...
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Seasonal Patterns and Trends in Dermatoses in Poland
PublicationThe amount of data available online is constantly increasing, including search behavior and tracking trends in domains such as Google. Analyzing the data helps to predict patient needs and epidemiological events more accurately. Our study aimed to identify dermatology-related terms that occur seasonally and any search anomalies during the SARS-CoV-2 pandemic. Methods: The data were gathered using Google Trends, with 69 entries...
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Abilities, Motivations, and Opportunities of Furloughed Employees in the Context of Covid-19: Preliminary Evidence From the UK
PublicationThe Covid-19 global pandemic is a crisis like no other, forcing governments to implement prolonged national lockdowns in an effort to limit the spread of the disease. As organizations aim to adapt and remain operational, employers can suspend or reduce work activity for events related to Covid-19 and claim government support to subsidize employee wages. In this way, some employees are placed on furlough (i.e., temporary unemployment)...
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Bezpieczne wymiarowanie ścinania ze zmiennym kątem THETA w kratownicach zastępczych według norm EC:2003, DIN:2003, PN:2002
PublicationPraca przedstawia zagadnienie wymiarowania elementów żelbetowych na ścinanie według zmodyfikowanej kratownicy Morscha, zamieszczonej w normach: europejskiej, niemieckiej i polskiej. Podano praktyczne wnioski odnośnie bezpiecznego przyjmowania kąta THETA, odwzorowującego nachylenie myślowo wydzielonych betonowych krzyżulców ściskanych.
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Micro-cracking pattern recognition of hybrid CNTs/GNPs cement pastes under three-point bending loading using acoustic emission technique
PublicationThe generation of microcracks has an important influence on the behaviour of concrete structures. In this study, the acoustic emission (AE) technique was used to investigate the fracture phenomena and micro-cracking behavior of hybrid carbon nanotubes (CNTs, the 1-D allotrope of carbon atoms) and graphene nanoplatelets (GNPs, 2D monolayer of sp2-hybridized carbon atoms), cement composites under three-point bending loading. In...
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Pounding Between Superstructure Segments in Multi-Supported Elevated Bridge with Three-Span Continuous Deck Under 3D Non-Uniform Earthquake Excitation
PublicationReports after severe ground motions show that the earthquake-induced structural pounding may lead to significant damage in elevated bridges. The aim of this paper is to analyse pounding between superstructure segments of a highway elevated bridge with three-span continuous deck under 3D non-uniform earthquake excitation, which is induced by spatial seismic effects related to the propagation of seismic wave. The conditional stochastic...
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Radiation dose distributions in three dimensions from tomographic optical density scanning of polymer gels: II. Optical properties of the BANG polymer gel
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A competition between two- and three-body dissociation channels in photo-double-ionization of tetrahydro-2H-pyran and 3,4-dihydro-2H-pyran molecules
PublicationVarious molecules possess structures consisting of the heterocyclic rings containing oxygen atoms. These substances often play a significant role in many different fields of chemistry, medicine, and biology. Due to a specific atomic composition and bond arrangement, many of these molecules retain unique electronic properties, which may be probed by diverse spectroscopic techniques, including those utilizing synchrotron radiation....
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Identification of synergistic and antagonistic actions of environmental pollutants: Bisphenols A, S and F in the presence of DEP, DBP, BADGE and BADGE·2HCl in three component mixtures
PublicationEcosystems are facing increased pressure due to the emission of many classes of emerging contaminants. However, very little is known about the interactions of these pollutants, such as bisphenols (BPs), plasticizers or pharmaceuticals. By employing bioluminescent bacteria (Microtox assay), we were able to define interactions between selected emerging pollutants (namely BPA, BPS, BPF, BADGE, BADGE·2HCl, DEP, DBP) in ternary mixtures, at...
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Intumescent flame retardants inspired template-assistant synthesis of N/P dual-doped three-dimensional porous carbons for high-performance supercapacitors
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Discussion on “Dynamic soil-structure interaction: A three-dimensional numerical approach and its application to the Lotung case study”. Poor performance of the HSS model
PublicationThe Hardening Soil Small (HSS) is a constitutive model being extension to the well established Hardening Soil Model (HS) accounting for the nonlinearity of small strain stiffness. It is implemented in commercial finite element computer codes for geotechnical analyses and used widely in research and design. The article deals with a problem known as overshooting after very small load reversals. It induces much higher stiffness than...
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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...
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Numerical Verification of Tests on the Influence of the Imposed Thermal Cycles on the Structure and Properties of the S700MC Heat-Affected Zone
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Heat Transfer During Pool Boiling of Water, Methanol and R141b on Porous Coated Horizontal Tube Bundles
PublicationThis paper presents the results of experimental investigation of water, methanol and R141b refrigerant boiling on horizontal porous coated tube bundles supposed to represent a flooded-type evaporator. Experiments were carried out for a bundle of 19 tubes in triangular layout for two pitch-to-diameter ratio values – 1.7 and 2.0 – in atmospheric and sub-atmospheric pressure conditions. Average heat transfer coefficients – both local,...