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Search results for: LOCAL HEATING
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The study of structure and surface morphology of lithium titanate sol-gel derived thin films
PublicationIn this paper the structure and the surface morphology of lithium titanate (LTO) thin films are presented. Nanocrystalline thin films were prepared by sol–gel method. To examine the influence of the annealing time on as-prepared films crystallization, the coatings were heated at different temperatures in the range of 500 °C–600 °C for 10, 20, 40 and 80 h. The structure of the obtained material was investigated using the X-ray diffraction...
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Hydroxyapatite deposition on the laser modified Ti13Nb13Zr alloy
PublicationThe Ti13Nb13Zr alloy was subjected to laser modification with the Nd:YAG laser provided that such treatment would increase the surface roughness followed improved adhesion of hydroxyapatite (HAp) coatings The hydroxyapatite was deposited by electrophoretic method in suspension of 0.5 g HA powder and 100 ml ethyl alcohol. The deposition was carried out for 10 min at 10 V voltage followed by drying at room temperature for 24 h and...
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Performance of the very high-temperature heat pump with low GWP working fluids
PublicationTraditional heat pumps are a very attractive pro-ecological solutions for a number of applications, including providing of heating or heat recovery from industrial processes. The application range of heat pumps could be greatly enlarged when the operating temperature would be increased to 130-150°C and/or the temperature lift can be increased to 50-100 K. In the paper, the very high temperature vapour-compressor based single stage...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART V) METHODS ENSURING CORRECT START-UP OF HYDRAULIC COMPONENTS OF SHIP’S ONBOARD DEVICES IN LOW AMBIENT TEMPERATURES
PublicationA large number of hydraulic devices and systems are started in low ambient temperatures. A good example of such a device is the hoisting winch on the ship. Starting hydraulic drive units in thermal shock conditions (rapid supply of hot oil to the cold unit) may lead to incorrect operation of the actuating system, for instance, due to the loss of clearance between cooperating elements. The article presents methods to prevent the...
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Cargo ships heat demand - operational experiment
PublicationThe paper presents the results of an experiment conducted on two cargo ships – a 5300 TEU container with a steam heating system and a 7500 dwt general cargo ship with a thermal oil system. On both ships research has been carried out using specially designed measuring equipment. After gathering data about flow velocity and temperatures (steam/ cooling water/ thermal oil/ seawater/ outside air), calculations have been done, resulting...
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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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Katalizatory wykorzystywane w syntezie biodiesla
PublicationRising prices of electricity, conventional fuels and heating require decisive steps in the further development of technologies based on renewable energy sources. These include geothermal-; hydrothermal-; aerothermal-; and solar energy. Due to the fact that the petrochemical industry is one of the fastest growing branches of the economy, we would like to expand on the topic related to biofuels. Biodiesel is an alternative fuel similar...
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Comparative study of operation of condensing and traditional boilers equipped with ORC module for electricity generation
PublicationThe study analyzed the operation of the "traditional" boiler equipped with the ORC module as the similar arrangement but with the condensing boiler. In the case of a conventional boiler there is noted a greater fuel consumption and the greater power generated than in the case of the unit with the condensing boiler. Postulated is the indicator in the form of a ratio of turbine power to the mass flow rate of fuel, which in turn gives...
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Multi-objective optimization of the ORC axial turbine for a waste heat recovery system working in two modes: cogeneration and condensation
PublicationDue to the demand of the district heating network and electric power grid ORC turbines can operate in the condensation and cogeneration modes. This approach requires the design of an expander which is characterized by high efficiency in each mode of operation. The paper is devoted to a multi-objective efficiency optimization of a one stage axial ORC turbine working on MM (Hexamethyldisiloxane). An Implicit Filtering algorithm (IF)...
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Molecular mobility of water protons under interaction with chemically modified starches. DSC and HMR-relaxation investigations
PublicationThe change of water protons mobility in the system chemically modified starches – water were investigated by DSC and NMR-relaxation methods. The amount of unfrozen water at subzero temperature as well as additional unfrozen water which appears after gelatinization have lower values for chemically modified starches in comparison with the native starch. The proton spin-spin relaxation time Т2 for chemically modified starch samples,...
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The Influence of Stretch Rod Speed on the Relationship between Preblown Bottle Aesthetic Quality and Final Blown Bottle Thickness Profile in Stretch Blow Molding from Preform Process
PublicationFrom a mechanical point of view, the aesthetic quality of preblown PET bottles and thickness profile of final blown PET bottles manufactured in ISBM process are determined by mechanical and thermal response of blown preforms. From the microscopic point of view the biggest influence on the mechanical and thermal properties of PET bottles have orientation and crystallization processes. From a technological point of view, the aesthetic...
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Technique for reducing erosion in large-scale circulating fluidized bed units
PublicationThis paper presents a methodology, implemented for a real industrial-scale circulating fluidized bed boiler, to mitigate the risk of heating surfaces exposed to an intensive particle erosion process. For this purpose, a machine learning algorithm was developed to support the boiler reliability management process. Having a tool that can help mitigate the risk of uncontrolled power unit failure without expensive and technically complex...
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Glass-ceramic joining of Fe22Cr porous alloy to Crofer22APU: interfacial issues and mechanical properties
PublicationThis work deals with the joining of porous Fe22Cr ferritic stainless steel to a dense Crofer22APU plate by using a silica-based, Ba-containing glass-ceramic. The chemical and interfacial stability and the mechanical properties of the joints were evaluated before and after thermal ageing at 700 ◦C for 500hrs. The sintering behaviour of the glass was assessed by using heating stage microscopy (HSM) to study the influence of a porous...
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Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-Cooling Function
PublicationThe nonlinear phenomena which associate with magnetoacoustic waves in a plasma are analytically studied. A plasma is an open system with external inflow of energy and radiation losses. A plasma’s flow may be isentropically stable or unstable. The nonlinear phenomena occur differently in dependence on stability or instability of a plasma’s flow. The nonlinear instantaneous equation which describes dynamics of nonwave entropy mode...
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Application analysis of a hybrid solid oxide fuel cell-gas turbine system for marine power plants
PublicationThe results of theoretical studies of the possibilities of using hybrid solid oxide fuel cell–gas turbine (SOFC-GT) systems for marine power plants are presented. A 500 kW auxiliary marine power plant scheme using stacks of SOFCs in combination with a regenerative gas turbine operating with over-expansion based on our recent patent application is proposed. The results of mathematical modelling showed the opportunity to obtain a...
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The Influence of a Photovoltaic Micro-Installation on the Low-Frequency Parameters of Electricity at PCC and Its Impact on the Thermal Characteristics of Selected Devices
PublicationThis manuscript illustrates the measurement results of parameters describing the quality of energy at the PCC (point of common coupling) of a photovoltaic micro-installation that can significantly affect devices in the same power grid. The analyses reflecting heating of selected devices used in domestic installations, which were performed in an isolated laboratory environment, are also indicated. The conducted study aimed at checking...
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Interpolation methods in GPR tomographic imaging of linear and volume anomalies for cultural heritage diagnostics
PublicationThis paper presents results of a ground penetrating radar (GPR) survey conducted in St. Joseph’s Church in Gdańsk, Poland. The aim of the study was to produce tomographic imaging of a renovated floor as well as the objects buried under the floor to detect linear and volume inclusions. The assumed track spacing was meaningfully greater than the single signal spacing in each track, which induced the need for interpolation methods...
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Burnout Investigation of Small Diameter Tubes Immersed in Nanofluids
PublicationThis paper deals with research into pool boiling critical heat flux (CHF) of water–Al2O3, water–TiO2 and water–Cu nanofluids on horizontal stainless steel tubes. The experiments were conducted under atmospheric pressure. Nanoparticles were tested at concentrations of 0.001%, 0.01%, 0.1% and 1% by weight. Ultrasonic vibration was used in order to stabilize the dispersion of the nanoparticles. Although dispersants were not used to...
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A multi‑criteria approach to investigate spatial distribution,sources, and the potential toxicological effect of polycyclic aromatic hydrocarbons (PAHs) in sediments of urban retention tanks
PublicationBottom sediments deposited in retention tanks (RTs) located on two urban streams (Oliwski and Strzyza) in the central part of Gdansk (Poland) were analysed for polycyclic aromatic hydrocarbons’ (PAHs) content. PAHs were extracted from samples with methylene chloride, then the extracts were subjected to clean-up applying the solid phase extraction (SPE) method. Quantitative and qualitative determination of 16 PAHs was performed...
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Nonlinear generation of non-acoustic modes by low-frequency sound in a vibrationally relaxing gas
PublicationTwo dynamic equations referring to a weakly nonlinear and weakly dispersive flow of a gas in which molecular vibrational relaxation takes place. are derived. The first one governs an excess temperature associated with the thermal mode, and the second one describes variations in vibrational energy. Both quantities refer to non-wave types of gas motion. These variations are caused by the nonlinear transfer of acoustic energy into...
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Nowoczesne metody termochemicznej konwersji biomasy w paliwa gazowe, ciekłe i stałe = Modern methods of thermochemical biomass conversion into gas, liquid and solid fuels
PublicationBiomass utilization through direct- or co-combustion with coal, based on coal, hydrogen and oxygen compounds chemical energy conversion into heat in boilers, is simultaneously the cheapest and - according to experts - economically least effective solution. In case of heat and electricity production in cogeneration process in biomass fueled heat and power stations (wood, straw, energetic plants, RDF etc), investment costs are little...
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Isothiocyanates may chemically detoxify mutagenic amines formed in heat processed meat
PublicationMeat consumption represents a dietary risk factor increasing the incidence of common cancers, probably due to carcinogenic amines (HAAs) formed upon meat heating. Interestingly, cancers whose incidence is increased by meat consumption, are decreased in populations consuming brassica vegetables regularly. This inverse correlation is attributed to brassica anticarcinogenic components, especially isothiocyanates (ITCs) that stimulate...
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Sposoby zagospodarowania ciepła odpadowego z silników napędowych jednostek pływających Cześć 1. Wykorzystanie ciepła do napędu urządzeń chłodniczych
PublicationEnergia chemiczna paliwa jest w wielu przypadkach zaledwie w połowie wykorzystana jako energia napędowa silnika. Pozostała część jako ciepło odpadowe przekazywana jest do otoczenia. Dzięki odpowiednim układom przetwarzania ciepło ze spalin można wykorzystać do wytwarzania chłodu lub jako ciepło użytkowe, w systemach HVAC (ang. heating, ventilation, air conditioning – ogrzewanie, wentylacja, klimatyzacja). Tym samym koszty pracy...
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Prediction of coking dynamics for wet coal charge
PublicationA 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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Nitrogen oxides removal from hydrogen flue gas using corona discharge in marine boilers: Application perspective
PublicationThis paper focuses on the combustion of hydrogen in boilers, as it appears to be a more effective method than using fuel cells for heating purposes due to higher boiler efficiency. One of the main disadvantages of hydrogen combustion in air is NOx formation. Therefore, the authors decided to introduce corona discharge as an inno- vative technique to clean hydrogen flue gas by effectively reducing NOx levels. The method involves...
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Synthesis of amides under microwave irradiation
PublicationAmides belong to the most important carboxylic acid derivatives. They are constituents of natural compounds like peptides and proteins. They found applications in many branches of science and industry, especially in pharmaceutical and polymer science. Conventional procedures for amide preparation involve reaction between amine and carboxylic acid or their more active derivatives such as acid chlorides, acid anhydrides or esters....
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A Theoretical and Experimental Study of Moderate Temperature Alfa Type Stirling Engines
PublicationThe Stirling engine is a device that allows conversion of thermal energy into mechanical energy with relatively high efficiency. Existing commercial designs are mainly based on the usage of high temperature heat sources, whose availability from renewable or waste heat sources is significantly lower than that of moderate temperature sources. The paper presents the results of experimental research on a prototype alpha type Stirling...
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Kinetic analysis of the reduction of a ternary system of Bi, Sb and Te oxides by hydrogen for BiSbTe3 synthesis
PublicationReduction in a hydrogen atmosphere of Bi2O3, Sb2O3 and TeO2 mixes oxides for the synthesis of BiSbTe3 was analysed. The reduction reactions of Sb2O3 and Sb2O4 oxides, as well as Bi2O3+Sb2O3 and Sb2O3+3TeO2 mix- tures, were also evaluated. The reduction of Sb2O4 is investigated for the first time. The reactions of the mixed oxides systems also were not the subject of research so far despite being used for synthesis of the (Bi,Sb)2Te3...
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Numerical Modelling of Forced Convection of Nanofluids in Smooth, Round Tubes: A Review
PublicationA comprehensive review of published works dealing with numerical modelling of forced convection heat transfer and hydrodynamics of nanofluids is presented. Due to the extensive literature, the review is limited to straight, smooth, circular tubes, as this is the basic geometry in shell-and-tube exchangers. Works on numerical modelling of forced convection in tubes are presented chronologically in the first part of the article....
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Optical and photoelectrochemical characterization of pulsed laser deposited Bi4V2O11, BICUVOX, and BIZNVOX
PublicationThin layers of three compounds from the BIMEVOX family (Bi4V2O11, Bi2V0.9Cu0.1O5.35, and Bi2V0.9Zn0.1O5.35) were prepared via pulsed laser deposition technique on quartz, silicon, and platinum foil and tested as photoanodes for water photooxidation. The film formation, as well as the crystallization upon heating, was characterized using X-ray diffraction and Raman spectroscopy. The optical properties were investigated using spectroscopic...
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Proton Conducting Ceramic Powder Synthesis by a Low Temperature Method
PublicationMolten salt synthesis (MSS) is a simple method for the preparation of ceramic powders with specific morphology. The main role of the molten salts is to increase the reaction rate and lower the reaction temperature. It occurs because of much higher mobility of reactants in the liquid medium than in the solid state. In this work the molten salt synthesis was applied to produce ceramic powders of La0995Ca0005NbO4 and BaCe09−xZrxY01O3....
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Utilization of rapeseed pellet from fatty acid methyl esters production as an energy source
PublicationRapeseed pellet – crushed seed residue from oil extraction is a by-product of fatty acid methyl esters production process. As other types of biomass, it can either be burned directly in furnaces or processed to increase its energetic value. Biomass is renewable, abundant and has domestic usage; the sources of biomass can help the world reduce its dependence on petroleum products, fossil coal and natural gas. Energetically effective...
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MHD Casson flow across a stretched surface in a porous material: a numerical study
PublicationIn this study, we examine the nature of magnetohydrodynamic (MHD) Casson flow of fluid across a stretched surface in a porous material. It studies how the behaviour of Casson fluids is affected by a number of variables, including thermal radiation, chemical processes, Joule heating, and viscosity dissipation. The Keller box strategy, based on the finite difference method (FDM), is used to tackle the complex numerical problem. Graphical...
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Thermal decomposition kinetics of dynamically vulcanized polyamide 6-acrylonitrile butadiene rubber-halloysite nanotube nanocomposites
PublicationThermally stable thermoplastic elastomer nanocomposites based on polyamide 6 (PA6), acrylonitrile butadiene rubber (NBR), and halloysite nanotubes (HNTs) were dynamically vulcanized, and their nonisothermal decomposition kinetics were examined. The Friedman, Kissinger–Akahira–Sunose (KAS), Ozawa–Wall–Flynn (FWO), and modified Coats–Redfern (m‐CR) isoconversional models were used to obtain information about the kinetics of the thermal...
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Improvement of Thrust Bearing Calculation Considering the Convectional Heating within the Space between the Pads
PublicationA modern thrust bearing tool is used to estimate the behavior of tilting pad thrust bearings not only in the oil film between pad and rotating collar, but also in the space between the pads. The oil flow in the space significantly influences the oil film inlet temperature and the heating of pad and collar. For that reason, it is necessary to define an oil mixing model for the space between the pads. In the bearing tool, the solutions...
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Cooperation of ORC installation with a gas boiler as a perspective co-generation system for households
PublicationThis paper reports tests of an innovative micro-CHP unit prototype, consisting of a traditional gas boiler and organic Rankine cycle (ORC), which incorporates original system components such as an axial vapour microturbine, evaporator and condenser. The system co-generates heat and electricity for a single household or a group of households. Electricity is only a by-product during production of heat. While testing the prototype,...
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Waste Tyres Pyrolysis for Obtaining Limonene
PublicationThis review deals with the technologies of limonene production from waste tyre pyrolysis. Thermal decomposition is attractive for tackling the waste tyre disposal problem, as it enables both: energy to be recovered and limonene to be obtained. This material management recycling of tyres is environmentally more beneficial than the burning of all valuable products, including limonene. Given this recoverability of materials from waste...
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Influence of process of straightening ship hull structure made of 316L stainless steel on corrosion resistance and mechanical properties
PublicationThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries, for architectural elements, and many others. The chemical composition of corrosion-resistant...
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Assessment of Corrosive Behaviour and Microstructure Characterization of Hybrid Friction Stir Welded Martensitic Stainless Steel
PublicationThis study examined the effect of induction heating on the microstructure and corrosion characteristics of hybrid friction stir welded AISI 410 stainless steel. Five joints have been produced with different friction stir welding parameters like welding speed, spindle speed, plunge depth, and induction power. Their microstructures were evaluated using a scanning electron microscope, and chemical composition was examined using...
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Thermomagnetic behavior of a semiconductor material heated by pulsed excitation based on the fourth-order MGT photothermal model
PublicationThis article proposes a photothermal model to reveal the thermo-magneto-mechanical properties of semiconductor materials, including coupled diffusion equations for thermal conductivity, elasticity, and excess carrier density. The proposed model is developed to account for the optical heating that occurs through the semiconductor medium. The Moore–Gibson–Thompson (MGT) equation of the fourth-order serves as the theoretical framework...
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Hydrogen production from ethanol In nitrogen microwave plasma At atmospheric pressure
PublicationHydrogen seems to be one of the most promising alternative energy sources. It is a renewable fuel as it could be produced from e.g. waste or bio-ethanol. Furthermore hydrogen is compatible with fuel cells and is environmentally clean. In contrast to conventional methods of hydrogen production such as water electrolysis or coal gasification we propose a method based on atmospheric pressure microwave plasma. In this paper we present...
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Real-time simulator of agricultural biogas plant
PublicationThis article presents a real-time simulator of an agricultural biogas plant. The project contains biogas and biomass circuits simulation, as well as heating circuit simulation with a complete control system and visualization interface of the whole process. The software tool used to simulate the plant work is CFD (Computational Fluid Dynamics), which enables a user to create and test simulation objects based on fundamental physical...
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Pipeline System for Heat Transportation from Nuclear Power Plant – an Optimizing Approach
PublicationOver the last few years heat piping insulation technology and pump systems efficiency have been significantly improved. Reduced thermal losses encourage heat transportation over long distances. It provides an opportunity for increasing thermodynamic efficiency of Nuclear Power Plants (NPPs) that are often located in rural areas because of safety issues. It can be achieved by Combined Heat and Power (CHP) generation, as heat produced...
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THE THERMODYNAMIC ANALYSIS OF THE SZEWALSKI HIERARCHIC VAPOUR CYCLE COOPERATED WITH THE SYSTEM OF HEAT RECOVERY
PublicationIn this paper, thermodynamic analysis of the Szewalski hierarchic vapour cycle cooperated with the system of heat recovery from exhaust gases are presented. According to that purpose, the CFM (Computation Flow Mechanics [1,3]) approach has correctly been used. The whole system consists of the first traditional steam cycle, the second organic Rankine cycle (ORC) and system of heat recovery with use of water with temperature 90...
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Preparation and characterisation of solution-cast Nafion membrane
PublicationNafion is a commercial name for a perfluorosulfonic polymer, which has been developed in 1962 by Dupont de Nemours. This polymer consists of a polytetrafluoroethylene backbone and regular spaced long perfluorovinyl ether pendant side chains terminated by a sulfonate ionic group. These sulfonate groups are responsible for cation-exchange properties of Nafion. Thanks to the ion-exchange properties, water permeability, good chemical,...
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Will NILM Technology Replace Multi-Meter Telemetry Systems for Monitoring Electricity Consumption?
PublicationThe estimation of electric power utilization, its baseload, and its heating, light, ventilation, and air-conditioning (HVAC) power component, which represents a very large portion of electricity usage in commercial facilities, are important for energy consumption controls and planning. Non-intrusive load monitoring (NILM) is the analytical method used to monitor the energy and disaggregate total electrical usage into appliance-related...
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Evaluating the influence of radiative heat flux on convective heat transfer from a vertical plate in air using an improved heating plate
PublicationThis article examines the influence of radiative heat flux on the accuracy of the results of free convective heat transfer in air. In order to carry out these tests, based on the experience gained during the operation of a plate heated on one side, compensated by a reverse heat loss flux counter-heater, a unique double-sided heating sandwich plate was designed and built, consisting of three thin epoxy resin plates reinforced with...
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THE PROPERTIES OF NANOSILVER – DOPED NANOHYDROXYAPATITE COATING ON THE Ti13Zr13Nb ALLOY
PublicationThe aim of this research was to study the properties of nanohydroxyapatite (nanoHAp) and nanohydroxyapatite, doped with nanosilver (nanoHAp/nanoAg), coatings obtained by an electrophoretic deposition process. The suspensions was prepared by dispersing 0.1 g of HAp nanopowder for nanoHAp coatings and 0.1 g of nanoHAp and 0.025 g nanoAg for nanoHAp/nanoAg coatings. The deposition was carried out for 1 min at 50 V voltage followed...
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Quantifying the effective mobilized RAP content during hot in-place recycling techniques
PublicationThe utilization of in-place recycling techniques is capable of consuming 100% reclaimed asphalt pavement (RAP). Hot in-place recycling (HIR) is one of the promising techniques to rehabilitate the pavements suffering from minor cracking issues through heat scarification, additive injecting, mechanical mixing, and compacting. However, the main concern of using 100% RAP in HIR remains as how much RAP can be activated and mobilized...
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Towards sugar-derived polyamides as environmentally friendly materials
PublicationAs part of our ongoing study investigating isohexide-based polyamides, we have synthesized isosorbide(bis(propan-1-amine)) (DAPIS) and studied its reactivity in the polymerization towards fully biobased polyamides. Polycondensation of nylon salts with various contributions of DAPIS afforded a family of homo- and copolyamides, which were characterized using complementary spectroscopic techniques. The chemical structure of the materials...