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Search results for: HEAT AFFECTED ZONE
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Comparison of traditional district heating with low temperature district heating systems featuring organic Rankine cycle and heat pump
PublicationPaper presents a comparison between a traditional district heating system with conventional boilers as a source of heat and electricity purchases from power utilities and a low temperature DH system incorporating the CHP with organic Rankine Cycle providing electricity and local heat pump raising the temperature of the DH fluid to the required temperature in the dwelling, meaning that both heat and electricity are produced within...
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Numerical solution analysis of fractional point kinetics and heat exchange in nuclear reactor
PublicationThe paper presents the neutron point kinetics and heat exchange models for the nuclear reactor. The models consist of a nonlinear system of fractional ordinary differential and algebraic equations. Two numerical algorithms are used to solve them. The first algorithm is application of discrete Grünwald-Letnikov definition of the fractional derivative in the model. The second involves building an analog scheme in the FOMCON Toolbox...
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Numerical simulation of temperature distribution of heat flow on reservoir tanks connected in a series
PublicationThe flow of temperature distribution through a medium in thermodynamic studies plays an important role in understanding physical phenomena in chemical science and petroleum engineering, while temperature distribution indicates the degree of reaction that must be undergone to obtain the final product. Therefore, this paper aims to present and apply the exponential matrix algorithm (EMA), differential transformation algorithm (DTA),...
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[IMe] Selected problems of heat and mass transfer
e-Learning Courses{mlang pl} Dyscyplina: Inżynieria mechaniczna (PG + IMP PAN) Zajęcia obowiązkowe Prowadzący: prof. dr. hab. inż. Dariusz Mikielewicz Liczba godzin: 20 h Forma zajęć: wykład {mlang} {mlang en} Discipline: mechanical engineering (GUT + IFFM PAS) Obligatory course Academic teacher: prof. dr. hab. inż. Dariusz Mikielewicz Total hours of training: 20 teaching hours Course type: lecture {mlang}
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Chemometric determination of solute-affected solvent vibrational spectra as a superior way of information extraction on solute solvation phenomena
PublicationW pracy zaprezentowano dwie chemometryczne metody wyznaczania widm zaburzonych rozpuszczalnika oraz liczby cząsteczek zaburzonych, na podstawie zmierzonych serii wibracyjnych widm FT-IR roztworów substancji. Pierwsza z metod została stworzona na podstawie Namiarowej Analizy Faktorowej (ang. Target Factor Analysis). Druga z nich wykorzystuje algorytm izolacji widm czystych składników z serii widm mieszanin. Działanie obu metod zostało...
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Measurements of the heat of hydration released by concrete specimens cured under adiabatic conditions
Open Research DataThe DataSet contains measurements of heat of hydartion of concrete cubes (150 x 150 x 150 mm) cured under adiabatic conditions. The specimens were moulded from six types of concrete mixtures produced in the laboratory conditions. Mix #1: Portland cement CEM I 42.5R and gravel aggregate, mix #2: CEM I 42.5R and basalt aggregate, mix#3: Portland-composite...
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Numerical analysis of the two‐phase steam‐air heat transfer flow induced in smooth and corrugated channel using the VOF model
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Double-stage ORC system based on various temperature waste heat sources of the negative CO2 power plant
PublicationAnalysed is the modification of the thermodynamic cycle with the negative CO2 power plant concept by its combination with the organic Rankine cycle. The analysed power plant operates on a gas produced from the gasification of sewage sludge. The negative emission term comes from the aggregated CO2 balance resulting from the capture of the CO2, while the sewage sludge is one of the inevitable environmental sources of CO2 to be avoided....
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Rip currents in the southern Baltic Sea multi-bar nearshore zone
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Impact of intense rains and flooding on mercury riverine input to the coastal zone
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Wave-induced bedload transport – a study of the southern Baltic coastal zone
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Mercury in particulate matter over Polish zone of the southern Baltic Sea
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Transportation of chips in the machining zone during cutting wood with circular saw
PublicationW pracy przedstawiono analizę odprowadznia wiórów ze strefy skrawania na zewnątrz materiału obrabianego przy przecinaniu drewna piłą tarczową.
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Mercury in the zoobenthos of the coastal zone of the Puck Bay (southern Baltic Sea)
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The prediction method of the shear angle in the cutting zone during wood sawing
PublicationW artykule opisano metodę przewidywania kąta ścinania w strefie skrawania dla przypadku przecinania drewna. Kąt ścinania był określany z wykorzystaniem współczesnej mechaniki pękania. Nieliniowe równanie opisujące tą wielkość było rozwiązywane numerycznie za pomocą metody iteracyjnej Newton-Raphson. Otrzymane wyniki obliczeń wykazują możliwość rozszerzenia obszaru modelowania efektów energetycznych procesu przecinania drewna nawet...
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Stresses in the zone of process openings in the shell of a vertical cylindrical steel tank
PublicationW dolnej części płaszcza zbiornika walcowego na ciecze konieczne jest wykonanie różnego rodzaju otworów technologicznych. Artykuł poświęcony jest analizie stanu naprężeń w strefie wzmocnień wykonywanych w sąsiedztwie otworów na rurociągi oraz na włazy wyczystkowe w płaszczu zbiornika. Ponieważ charakter zmian naprężeń, a więc i wzmocnień w strefie obu rodzajów otworów jest różny dlatego artykuł podzielony jest na dwie części, z...
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Building modernization located in the conservation protection zone in the aspect of technical conditions
PublicationThe paper presents a description of the technical condition of the building after many years of operation and analyzes the impact of the current use and the lack of regular periodic repairs on the technical efficiency of the building. The influence of the technical solutions applied during the construction of the building on the current limitations related to the planned, target change in the way of use was discussed. Variant conceptual...
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BEHAVIOR OF REINFORCED CONCRETE BEAMS CONTAINING LIGHTWEIGHT AGGREGATE IN THE TENSILE ZONE
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Liquid circulation in the agitated airlift reactor with the high gas disengagement zone
PublicationPrzedstawiono doświadczalne zależności stopnia zatrzymania gazu i prędkości cyrkulacji cieczy od prędkości przepływu gazu i częstości obrotów mieszadła. Obserwowano wzrost prędkości cyrkulacji cieczy ze wzrostem wysokości strefy napowietrzania. Dla niskich częstości obrotów mieszadła prędkość cyrkulacji cieczy wzrastała wraz ze wzrostem prędkości przepływu gazu, natomiast dla wysokich cząstości obrotów mieszadła prędkość cyrkulacji...
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Sea to air transport of trace gases in the coastal zone: a literature review
PublicationW pracy przedstawiono informacje i dane liczbowe dotyczące zjawiska wymiany składników śladowych (CO2, N2O, CH4, DMS, COS, NH3, metyloaminy, lotne związki halogenoorganiczne, CO) pomiędzy powierzchnią morza i powietrzem atmosferycznym w strefie przybrzeżnej. Dokonano oceny ogólnej emisji tych związków oraz podano informacje o stężeniach i o strumieniach (w skali rocznej).
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Influence of annealing on joint zone of explosive welded and rolled Al-Cuplate
PublicationRosnące wciąż wymagania co do metalowych materiałów jednorodnych przyczyniło się do zwiększenia zainteresowania materiałami platerowanymi. Blachy platerowane często znajdują zastosowanie w przemyśle chemicznym i petrochemicznym jako materiały antykorozyjne odporne na działanie agresywnego środowiska, w przemyśle okrętowym jako łączniki stopów aluminium ze stalą, w budowie zgrzewarek jako połączenia szczęk z blachą stalową, w przemyśle...
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Interactions between river catchments and the coastal zone: the EuroCat-VisCat Project
PublicationW pracy przedstawiono: założenia oraz schemat organizacyjny projektu finansowanego przez Wspólnotę Europejską (EuroCat); program badań projektu VisCat realizowanego przez zespoły z UMK oraz PG. Omówiono również prace związane z tworzeniem bazy danych nt. stanu rzeki Wisły i Zatoki Gdańskiej.
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Effect of heterogeneity on shear zone formation during plane strain compression.
PublicationW artykule przedstawiono wyniki numerycznej analizy ściskania w płaskim stanie odkształcenia dla materiałów granulowanych. Obliczenia przeprowdzono z modelem hipoplastycznym rozszerzonym o obroty i długość charakterystyczną. Obliczenia wykonno dla różnych rodzajów imperfekcji w próbce piasku zagęszczonego i luźnego.
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Fundamentals of thermodynamics and heat transfer, W/C, GTM (WCh), sem.04, zimowy 23/24 (PG_00048767)
e-Learning CoursesTable of contents presented on the course: Basic terms.The first law of thermodynamics for closed and open systems.The properties of perfect, semi-perfect and real gases.Gas rights. Thermal and caloric state equation.Thermodynamic transformations of a perfect gas.Gaseous thermodynamic cycles. The second law of thermodynamics.Steam and steam cycles.Basics of heat exchange.
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Utilisation of bleed steam heat to increase the upper heat source temperature in low-temperature ORC
PublicationW pracy przedstawiono możliwość dogrzewu obiegu ORC za pomocą pary upustowej.
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A model of combined heat and power generating plant with urban heat distribution network for production scheduling
PublicationPoruszono zagadnienie związane z pracowaniem harmonogramu produkcji elektrociepłowni. Uwzględniony został wpływ zachowania się miejskiej sieci ciepłowniczej na pracę elektrociepłowni. Możliwe jest również modelowanie współpracy ze zbiornikiem ciepła.
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Liquid crystal technique application for heat transfer investigation in afin-tube heat exchanger element
PublicationPublikacja przedstawia rezultaty prac autorów w zakresie wykorzystania termografii ciekłokrystalicznej w badaniach wymiany ciepła dla różnych elementów wymienników ciepła. Technika ta z powodzeniem została zastosowana do analizy zabudowy wymiennika na jego efektywność.
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Liquid crystal technique application for heat transfer investigation inafin-tube heat exchanger element
PublicationPublikacja przedstawia rezultaty prac autorów w zakresie wykorzystania techniki ciekłokrystalicznej w badaniach wymiany ciepła dla elementów wymiennika ciepła. Technika ta z powodzeniem została zastosowana do analizy sposobu zabudowy wymiennika na jego efektywność.
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Numerical Study on Mitigation of Flow Maldistribution in Parallel Microchannel Heat Sink: Channels Variable Width Versus Variable Height Approach
PublicationMicrochannel heat sink on one hand enjoys benefits of intensified several folds heat transfer performance but on the other hand has to suffer aggravated form of trifling limitations associated with imperfect hydrodynamics and heat transfer behavior. Flow maldistribution is one of such limitation that exaggerates temperature nonuniformity across parallel microchannels leading to increase in maximum base temperature. Recently, variable...
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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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Experimental investigation of M-shape heat transfer coefficient distribution of R123 flow boiling in small-diameter tubes
PublicationW publikacji przedstawiono wyniki badań wrzenia czynnika R123 w srebrnych rurkach o małych średnicach (średnice wewnętrzne wynosiły odpowiednio 1.15 mm i 2.3 mm). Badania przeprowadzono w szerokim zakresie stopnia suchości pary (0.01-0.9), gęstości strumienia masy (650-3000 kg/(m2s)) oraz gęstości strumienia ciepła (40-80 kW/m2). W badaniach wykazano, że istnieją dwa lokalne maksima współczynnika przejmowania ciepła w jego profilu...
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A common method for calculation of flow boiling and flow condensation heat transfer coefficients in minichannels with account of nonadiabatic effects
PublicationW pracy przedstawiono metodę ogólną wyznaczania współczynników przejmowania ciepła podczas wrzenia w przepływie i kondensacji w przepływie w minikanałach z uwzględnieniem efektu nieadiabatycznego. Uwzględnia ona wpływ modyfikacji naprężeń stycznych na granicy ciecz-para na wymianę ciepła.
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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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The topography of as-quenched and heat treated 58(2Bi2O3-V2O5)-42SrB4O7 glasses measured with confocal microscope
Open Research DataThe topography of as-quenched and heat treated 58(2Bi2O3-V2O5)-42SrB4O7 glasses measured with confocal microscope.
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AUGMENTATION OF THE CRITICAL HEAT FLUX IN WATER-Al2O3, WATER-TiO2 AND WATER-Cu NANOFLUIDS
PublicationThe main aim of the proposed study is therefore recognition of the phenomena accompanying nucleate boiling crisis of selected nanofluids during boiling on horizontal tubes of various outside diameters. Of particular interest is impact of contact angle and tube diameter on the value of critical heat flux. The results obtained should give more light on the nature of nucleate boiling crisis and will serve as a basis for future theoretical...
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Computational fluid dynamics simulation of heat transfer from densely packed gold nanoparticles to isotropic media
PublicationThis work aims to determine and compare heat generation and propagation of densely packed gold nanoparticles (Au NPs) induced by a resonant laser beam (532 nm) according to the Mie theory. The heat flux propagation is transferred into the materials, which here are: silica glass; soda-lime-silica glass; borosilicate glass; polymethyl methacrylate (PMMA); polycarbonate (PC); and polydimetylosiloxane (PDMS). This analysis aims to...
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Modelling of two-component turbulent mass and heat transfer in air-fed pressurised suits
PublicationIn this paper the modelling of an important industrial problem is addressed, which involves the two-component turbulent flow with heat transfer that takes place inside protective clothing. The geometry of the flow boundaries is reconstructed in a CAD system from photogrammetry scan data. The overall model is sufficiently realistic to allow, after validation, design improvements to be tested. Those presented here allow the reduction...
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The influence of welding heat input on the quality and properties of high strength low-alloy dissimilar steel butt joints
PublicationThe paper presents the results of non-destructive and destructive tests of dissimilar highstrength low-alloy S460ML and S460N steel butt joints. These steels are characterized by similar mechanical properties, but their carbon equivalent CeIIW values are much different. The joints were made using different values of heat input for each welding bead. They were tested by non-destructive methods: visual, penetrant, radiographic and...
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Numerical Investigation of Nuclear Reactor Kinetic and Heat Transfer Fractional Model with Temperature Feedback
PublicationAbstract—In the paper, the numerical results concerning the kinetics and proposed heat exchange models in nuclear reactor based on fractional calculus are presented for typical inputs. Two fractional models are proposed and compared with the model based on ordinary derivative. The first fractional model is based on one of the generalized Cattaneo equations. The second one is based on replacing the ordinary to fractional order of...
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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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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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The biotic and abiotic mercury at the coastal zone of Gulf of Gdańsk
Open Research DataConcentration of neurotoxin Hg (mercury) was determined monthly form 01.2012 to 05.2013 (total and suspended) in the surface microlayer and the surface water as well as in: phytoplankton, zooplankton, epilithon, epifithon, phytobenthos (macroalgae and angiosperms), zoobenthos, and in the sediment. The study was conducted in the coastal zone of the Puck...
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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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Towards enhanced heat and mass exchange in adsorption systems: The role of AutoML and fluidized bed innovations
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Prediction of flow boiling heat transfer coefficient for carbon dioxide in minichannels and conventional channels
PublicationIn the paper are presented the results of calculations using authors own model to predict heat transfer coefficient during flow boiling for carbon dioxide. The experimental data from various researches were scrutinised conducted for a full range of quality variation and wide range of mass velocity. The aim of the study was to test the sensitivity of the in-house model. The work shows the importance of taking into account surface...
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Thermodynamic and economic analysis of nuclear power unit operating in partial cogeneration mode to produce electricity and district heat
PublicationThis paper presents the methodology of techno-economic analysis for a nuclear unit operating in partial cogeneration mode and its application for the case study: a nuclear power plant planned in Poland. The research objectives were: to propose EPR, AP1000 and ESBWR nuclear condensing-extraction turbine systems modifications required for operation in cogeneration, to determine optimal heat production and heat transport line (HTL)...
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HTM-Journal of Heat Treatment and Materials
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WSEAS Transactions on Heat And Mass Transfer
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INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
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American Journal of Heat and Mass Transfer
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