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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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Computational model for simulation of lifeboat motions during its launching from ship in rough seas
PublicationW artykule przedstawiono model obliczeniowy 3 D, opisujący ruch obiektu w 6 stopniach swobody (6DoF), do symulacji ruchu jedno- lub dwuzawiesiowej łodzi ratunkowej lub ratowniczej podczas opuszczania ze statku na wzburzonej wodzie. Jest to złożony model uwzględniający warunki morskie oraz elastyczność i własności tłumiące elementów i mechanizmów żurawika, liny oraz kadłuba łodzi. Ponadto przedstawiono przykładowe wyniki obliczeń...
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Abuse or contamination? Ratio determination of clenbuterol enantiomers to distinguish between doping use and meat contamination
PublicationClenbuterol has been detected in urine of several athletes during routine doping control in the past years. Athletes claimed that the clenbuterol was ingested by eating contaminated meat. Providing analytical prove for this claim is difficult. clenbuterol consists of two enantiomers, R(-) and S(+)-clenbuterol. Currently available human and veterinary preparations were found to consist of a racemic mixture of both enantiomers. When...
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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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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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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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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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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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Potential of bacteriocins from lab to improve microbial quality of dry-cured and fermented meat products [pdf]
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Effects of Heat and Momentum Gain Differentiation during Gas Detonation Spraying of FeAl Powder Particles into the Water
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Application of COSMO-RS-DARE as a Tool for Testing Consistency of Solubility Data: Case of Coumarin in Neat Alcohols
PublicationCoumarin is a naturally occurring lactone-type benzopyrone with various applications in the pharmaceutical, food, perfume, and cosmetics industries. This hydrophobic compound is poorly soluble in water but dissolves well in protic organic solvents such as alcohols. Despite the extensive use of coumarin, there are only a few reports documenting its solubility in organic solvents, and some reported data are incongruent, which...
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Heat transfer and pressure drop during flow boiling of refrigerant/oil mixture inside smooth tube
PublicationW pracy przedstawiono wyniki badań współczynnika przejmowania ciepła i spadku ciśnienia podczas wrzenia czystych oraz zaolejonych czynników chłodniczych (R22, R134a, R407C) wrzących w poziomej stalowej rurce.
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Meat products Brassica exploiting anticarcinogenic potential of cabbage phytochemicals: Polish path to bio-inspired foods
PublicationBadania populacyjne ostatnich dwóch dziesięcioleci wskazują na sposób odżywiania jako jeden z głównych czynników zagrożenia chorobami cywilizacyjnymi, z nowotworami włącznie. W przypadku chorób nowotworowych głównym elementem diety sprzyjającej kancerogenezie jest czerwone mięso. Ze względu na wartość odżywczą i powszechność spożycia produktów mięsnych, poprawienie ich wartości żywieniowej staje się problemem o istotnym znaczeniu...
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Possibility of thermal imaging use in studies of natural convection heat transfer on the example of an isothermal vertical plate
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Two-phase flow phenomena assessment in minichannels for compact heat exchangers using image analysis methods
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Disorder of Biological Quality and Autophagy Process in Bovine Oocytes Exposed to Heat Stress and the Effectiveness of In Vitro Fertilization
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Wpływ obróbki cieplnej na strukturę stali krzemowej. The heat treatment influence on the silicon steel morphology
PublicationStal sprężynową 55S2 poddano obróbce cieplnej przy poprawnych i zawyżonych paramatrach temperaturowo-czasowych. Dla materiału o wadliwej strukturze wyjściowej, dobór wyższych temperatur i czasów obróbki pozwolił na otrzymanie bardziej poprawnych struktur i własności materiału.
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The Major Heat Shock Proteins, Hsp70 and Hsp90, in 2-Methoxyestradiol-Mediated Osteosarcoma Cell Death Model
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Computational analysis of power-law fluids for convective heat transfer in permeable enclosures using Darcy effects
PublicationNatural convection is a complex environmental phenomenon that typically occurs in engineering settings in porous structures. Shear thinning or shear thickening fuids are characteristics of power-law fuids, which are non-Newtonian in nature and fnd wide-ranging uses in various industrial processes. Non-Newtonian fuid fow in porous media is a difcult problem with important consequences for energy systems and heat transfer. In this...
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Efficiency of Electricity Production Technology from Post-Process Gas Heat: Ecological, Economic and Social Benefits
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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,...
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Comparison of heat transfer characteristics in surface cooling using microjets with water, ethanol and HFE7100 as test fluids
PublicationAccurate control of cooling parameters is required in ever wider range of technical applications. It is known that reducing the dimensions of the size of nozzle leads to an increase in the economy of cooling and improves its quality. Present study describes research related to the design and construction of the nozzles and microjet study, which may be applied in many technical applications such as in metallurgy, electronics, etc....
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The influence of moderate pressure and subzero temperature on the shelf life of minced cod, salmon, pork and beef meat
PublicationThe effect of moderate pressure at subzero temperature on natural microflora of minced cod, salmony, pork and beef meat was studied. Pressure of 193 MPa at –20 °C caused reduction of total bacterial count in pork and beef meat by 1.1 and 0.6 log cycles, respectively, and by about 1.5 log cycles in fish meat. Under these conditions the psychrophilic and psychrotophic bacteria were below the detection limit (<10CFU/g of sample) in...
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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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Thermal Design of Double Pipe Heat Exchanger Used as an Oil Cooler in Ships: A Comparative Case Study
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Design and Thermodynamic Analysis of a Steam Ejector Refrigeration/Heat Pump System for Naval Surface Ship Applications
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Heat transfer during pool boiling of water, methanol and R141b on porous coated horizontal tube bundles
PublicationPrzedstawiono wyniki badań eksperymentalnych wrzenia wody, metanolu i R141b na poziomym pęczku rur pokrytych metaliczna powłoką porowatą. Badania przeprowadzono dla podziałek rur 1.7d oaz 2d, przy ciśnieniu atmosferycznym i podciśnieniu.
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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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Testing Students’ Entrepreneurial Self-Efficacy as an Early Predictor of Entrepreneurial Activities. Evidence From the SEAS Project
PublicationOver the last forty years, since Bandura (1977) introduced the concept of self-efficacy, there have been a constantly growing number of research publications using this concept. Its early development resulted in the creation of a new construct of entrepreneurial self-efficacy (ESE) proposed for the first time by (Chen et al. 1998). Since then, many different groups of research concerning ESE have emerged - one of them is the study...
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COMPARISON OF PREDICTIVE METHODS FOR FLOW BOILING HEAT TRANSFER IN CONVENTIONAL CHANNELS AND MINICHANNELS – THE EFFECT OF REDUCED PRESSURE
PublicationIn the paper are presented the results of follow on studies from [1]–[3] using authors own model to predict heat transfer coefficient during flow boiling. The model has been tested against a large selection of experimental data collected from various researchers to investigate the sensitivity of the in-house developed model. The collected experimental data came from various studies from literature and were conducted for the full...
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Comparison of predictive methods for flow boiling heat transfer in conventional channels and minichannels - the effect of reduced pressure
PublicationIn the paper are presented the results of follow on studies from [1]–[3] using authors own model to predict heat transfer coefficient during flow boiling. The model has been tested against a large selection of experimental data collected from various researchers to investigate the sensitivity of the in-house developed model. The collected experimental data came from various studies from literature and were conducted for the full...
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Experimental investigation on straight and u-bend double tube heat exchanger with active and passive enhancement methods
PublicationAuthors in this work want to demonstrate the possibility to increase the heat transfer efficiency by using simple wire coil inserts to create turbulent flow in the boundary layer as well as air blowing into the annulus of the pipe. In the study, Wilson plot approach was applied in order to estimate heat transfer coefficients for all heat exchanger (HX) configurations. The study focuses on experimental values of heat transfer coefficient...
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Numerical model for thin liquid film with evaporation and condensation on solid surfaces in systems with conjugated heat transfer
PublicationCondensation and evaporation processes from wetted surfaces are of utmost importance in many technological or industrial applications. In many devices such as home-appliances and air conditioning systems just to name a few, condensation and evaporation processes greatly impact their performance and energy efficiency; The physics of these processes is quite complex, involving conjugate heat transfer among solid–liquid film-gaseous...
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Preliminary results from HEDGEHOG REXUS Project - sounding rocket experiment on accelerations, vibrations and heat flow
PublicationAs access to space conditions becomes more available, both technically and economically, scientists' interest in launching finer and more sophisticated experiments grows. This applies now more than ever to fragile by nature biological and chemical experiments. To be qualified for launch, such experiments need to be carefully tested prior to the event. The tests should represent actual launch conditions as closely and in as detailed...
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Preliminary results from HEDGEHOG REXUS project – A sounding rocket experiment on accelerations, vibrations and heat flow
PublicationDuring flight, a sounding rocket is subject to a unique environment - severe vibrations and substantial heat flux. In order to design payloads, precise measurement of these conditions is required. This paper presents preliminary results from HEDGEHOG REXUS Project, whose scientific goal was to characterise the thermal and dynamic environment of REXUS sounding rockets. For this purpose, two new sensors have been designed - mechanical...
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Thermal and economic investigation of straight and U-bend double tube heat exchanger with coiled wire turbulator
PublicationExperimental 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...
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Changes in enzymatic activity of fish and slaughter animals meat after high pressure treatment at subzero temperatures
PublicationThe aim of this study was to determine changes in the activity of proteolytic enzymes and transglutaminase of fish and mammal meat after pressurization at subzero temperatures. The activity was measured at the optimal pHs determined for enzymes from particular types of tested meat. It was found that increasing the pressure in the range of 60–193 MPa, did not change significantly the activity of acidic proteases of cod flesh, while...
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Electronic States of Tris(bipyridine) Ruthenium(II) Complexes in Neat Solid Films Investigated by Electroabsorption Spectroscopy
PublicationWe present the electric field-induced absorption (electroabsorption, EA) spectra of the solid neat films of tris(bipyridine) Ru(II) complexes, which were recently functionalized in our group as photosensitizers in dye-sensitized solar cells, and we compare them with the results obtained for an archetypal [Ru(bpy)3]2+ ion (RBY). We argue that it is difficult to establish a unique set of molecular parameter values by discrete parametrization...
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The Staged Combustion of Meat-and-Bone Meal:The Characteristics of Conversion Sub-processes and Large-Scale Process Outputs
Publicationt Organic waste has been playing an increasingly important role in the energy market as those that may support the economies in pursuing towards decarbonization by increasing the share of renewables in the overall energy balance. In this group of alternative fuels, meat-and-bone meals being a post-production waste of the steadily developing meat industry, constitute a considerable proportion. Though they are rich in minerals, their...
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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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Improved finite element method for flow, heat and solute transport of Prandtl liquid via heated plate
PublicationIn the current study, a vertical, 3D-heated plate is used to replicate the generation of heat energy and concentration into Prandtl liquid. We discuss how Dufour and Soret theories relate to the equations for concentration and energy. In order to see how efectively particles, interact with heat and a solvent, hybrid nanoparticles are used. It does away with the phenomena of viscous dissipation and changing magnetic felds. The motivation...
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Promising Nanoparticle-Based Heat Transfer Fluids—Environmental and Techno-Economic Analysis Compared to Conventional Fluids
PublicationProviding optimal operating conditions is one of the major challenges for effective heating or cooling systems. Moreover, proper adjustment of the heat transfer fluid is also important from the viewpoint of the correct operation, maintenance, and cost efficiency of these systems. Therefore, in this paper, a detailed review of recent work on the subject of conventional and novel heat transfer fluid applications is presented. Particular...
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Analysis of Organic Rankine Cycle efficiency and vapor generator heat transfer surface in function of the reduced pressure
PublicationIn the paper presented is analysis of the influence of reduced pressure on efficiency and heat transfer area of vapor generator of Organic Rankine Cycle (ORC) in case of subcritical and supercritical parameters of operation. Compared are two cases of subcritical and supercritical ORC featuring a similar arrangement of heat source supply and heat removal, that is featuring the same temperatures of working fluid before the turbine,...
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Sea Captains’ Views on Automated Ship Route Optimization in Ice-covered Waters
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Surf Zone Currents in the Coastal Zone of the Southern Baltic Sea – a Modelling Approach
PublicationNearshore currents in a multi-bar non-tidal coastal zone environment located in the Southern Baltic Sea are studied. Spatiotemporal seaward-directed jets – so-called rip currents – are an important part of the nearshore current system. In previous research, Dudkowska et al. (2020) performed an extended modelling experiment to determine the wave conditions that are conducive to the emergence of rip currents. In this paper, the...
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The impact of declining oxygen conditions on pyrite accumulation in shelf sediments (Baltic Sea)
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Spatial distribution of phosphorus forms in sediments in the Gulf of Gdańsk (southern Baltic Sea)
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Multiple bifurcation in the solution set of the von Karman equations with S^{1}-symmetries
PublicationRozważmy cienką, sprężystą, kołową płytę, położoną na sprężystym podłożu, poddawaną działaniu sił ściskających koncentrycznie wzdłuż jej brzegu. Formy równowagi takiej płyty są rozwiązaniami równań von Karmana z dwoma parametrami określonych na dysku w R^{2}. Są to równania różniczkowe cząstkowe rzędu czwartego. Można je zapisać jako równanie operatorowe F(x,p)=0 w przestrzeniach Höldera, gdzie zmienna x odpowiada formom równowagi...
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Estimation of Solar Energy Influx to the Sea in the Light of Fast Satellite Technique Development
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