displaying 1000 best results Help
Search results for: POROUS HEAT SURFACE
-
Improved performance of LaNi0.6Fe0.4O3 solid oxide fuel cell cathode by application of a thin interface cathode functional layer
PublicationIn this work, novel functional layers were prepared by a low temperature spray pyrolysis method on the oxygen side of the solid oxide cells. Thin layers of Ce0.8Gd0.2O2 and LaNi0.6Fe0.4O3 are prepared between the electrolyte and the porous oxygen electrode. Additionally the influence of the sprayed ceria barrier layer on the zirconia based electrolyte with the new layers is evaluated. Impedance spectroscopy results show improvement...
-
Acoustic lifecycle study of the double-layer porous asphalt on E4 in Huskvarna, Sweden
PublicationIn 2010 a double-layer porous asphalt concrete (DPAC) pavement was constructed on the E4 motorway through the Swedish city Huskvarna. Earlier experience in Sweden indicated that it was feasible to obtain a high initial noise reduction but due to the widespread use of studded tires in winter, clogging and ravelling created losses of around 2 dB per year, with an expected acoustical lifetime of only 3 years. However, the improved...
-
Materials Design for the Titanium Scaffold Based Implant
PublicationThe main objective of here presented research is a design the scaffold/porous titanium(Ti) alloy based composite material demonstrating better biocompatibility, longer lifetime andbioactivity behaviour for load-bearing implants. The development of such material is proposed bymaking a number of consecutive tasks. Modelling the mechanical, biomechanical and biologicalbehavior of porous titanium structure and an elaboration of results...
-
Materials Design for the Titanium Scaffold Based Implant
PublicationThe main objective of here presented research is a design the scaffold/porous titanium(Ti) alloy based composite material demonstrating better biocompatibility, longer lifetime andbioactivity behaviour for load-bearing implants. The development of such material is proposed bymaking a number of consecutive tasks. Modelling the mechanical, biomechanical and biologicalbehavior of porous titanium structure and an elaboration of results...
-
New synthesis route of highly porous InxCo4Sb12 with strongly reduced thermal conductivity
PublicationHighly porous, In-filled CoSb3 skutterudite materials with an attractive thermoelectric figure of merit (ZT * 1) and corresponding dense samples were fabricated through the cost-effective method of reduction in oxides in dry hydrogen and the pulsed electric current sintering (PECS) method, respectively. The reduction process was described in detail using in situ thermogravimetric analysis of Co2O3, Sb2O3 and In(NO3)35H2O separately...
-
Low Noise Poroelastic Road Pavements Based On Bituminous Binder
PublicationTire/road noise is the dominant source of traffic noise. It depends both on the tire design and on the characteristics of road pavements as well as on the vehicles’ operating conditions. Due to the fact that conventional (pneumatic) car tires have almost reached the limits of their ability to further reduce their noisiness, it is widely believed that the additional reduction of tire noise will be possible mainly through modifications...
-
Metal-Organic Framework (MOF)/Epoxy Coatings: A Review
PublicationEpoxy coatings are developing fast in order to meet the requirements of advanced materials and systems. Progress in nanomaterial science and technology has opened a new era of engineering for tailoring the bulk and surface properties of organic coatings, e.g., adhesion to the substrate, anti-corrosion, mechanical, flame-retardant, and self-healing characteristics. Metal-organic frameworks (MOFs), a subclass of coordinative polymers...
-
Powder metallurgy of the porous Ti-13Nb-13Zr alloy of different powder grain size
PublicationThe objective of the present project was to determine the effects of powder granulation (fraction of grain size) for the Ti-13Nb-13Zr alloy, produced by powder metallurgy, on its porosity, grain cohesion, compressive strength, and Young`s modulus. Two powder fractions, 45–105 µm, and 106–250 µm were applied. The 50 mass pct of NH4HCO3 was added as a space holder. The specimens were in compaction stage uniaxially pressed at pressure...
-
Surface Science - 2023/2024
e-Learning CoursesThe course is not a full time lecture but on the consultation/handouts. The consulations are held every two weeks. The course is based on the Springer textbook: Surface Science An Introduction Downloadable at: https://link.springer.com/book/10.1007/978-3-662-05179-5 (PG network or vpn access) The goal of the subject is the presentation of basic problems resulting from he existence of interfacebetween material objects...
-
Modeling two phase flow in large scale fractured porous media with an extended multiple interacting continua method
PublicationWe present a two phase flow conceptual model, the corresponding simulator (2pMINC) and a workflow for large-scale fractured reservoirs, based on a continuum fracture approach which uses the multiple interacting continua (MINC) method complemented with an improved upscaling technique. The complex transient behavior of the flow processes in fractured porous media is captured by subgridding the coarse blocks in nested volume elements...
-
Metoda f-chart w zastosowaniu do projektu instalacji solarnej w budownictwie jednorodzinnym
PublicationW artykule przedstawiono algorytm obliczeń cieplnych związanych z konwersją promieniowania cieplnego oraz analizę efektów pracy instalacji solarnej przy użyciu metody korelacyjnej f-chart. Zaprezentowany algorytm obliczeń cieplnych oraz omówiona w artykule podstawowa odmiana metody f-chart zostały poparte przykładem obliczeniowym dla instalacji solarnej, która wykorzystywana jest do wspomagania układu przygotowania c.w. dla potrzeb...
-
Polyurethane porous scaffolds (PPS) for soft tissue regenerative medicine applications
PublicationTissue engineering requires suitable polymeric scaffolds, which act as a physical support for regenerated tissue. A promising candidate might be polyurethane (PUR) scaffold, due to the ease of the PUR properties design, which can be adjusted directly to the intended purpose. In this study, we report a successful fabrication of porous polyurethane scaffolds (PPS) using solvent casting/particulate leaching technique combined with...
-
Electrocatalytic performance of oxygen-activated carbon fibre felt anodes mediating degradation mechanism of acetaminophen in aqueous environments
PublicationCarbon felts are flexible and scalable, have high specific areas, and are highly conductive materials that fit the requirements for both anodes and cathodes in advanced electrocatalytic processes. Advanced oxidative modi- fication processes (thermal, chemical, and plasma-chemical) were applied to carbon felt anodes to enhance their efficiency towards electro-oxidation. The modification of the porous anodes results in increased...
-
N-doped mesoporous carbon nanosheets obtained by pyrolysis of a chitosan–melamine mixture for the oxygen reduction reaction in alkaline media.
PublicationBy simple thermal decomposition of low-cost precursors (chitosan, melamine) in an inert atmosphere, nitrogen-doped porous carbonaceous materials were prepared. The samples pyrolyzed at 700 C are composed of mainly mesoporous nitrogen-doped carbon nanosheets and partially graphitized carbon. The nanosheets contain a disordered area due to the strain imposed by the presence of nitrogen and/or oxygen groups in their structure. Some...
-
Impact of strontium non-stoichiometry of SrxTi0.3Fe0.7O3-δ on structural, electrical, and electrochemical properties for potential oxygen electrode of intermediate temperature solid oxide cells
PublicationThis work presents the results of a comprehensive study on the impact of the A-site non-stoichiometry of SrxTi0.3Fe0.7O3-δ (x = 0.90, 0.95, 1.00, 1.05) ceramics on their physicochemical properties. The materials were fabricated by the conventional solid-state reaction method and their structure was determined by X-ray diffractometry, X-ray photoelectron spectroscopy and electron microscopy. Their sintering and thermal expansion...
-
The new silica-based coated SPME fiber as universal support for the confinement of ionic liquid as an extraction medium
PublicationThe new silica-based SPME fiber coating is reported for the first time as universal support purposed to confinement of ionic liquid as an extraction medium. Fiber coating was prepared by the sol-gel process, using potassium silicate (K2SiO3) as a precursor and dimethylformamide (DMF) as a pore-forming medium. The concept of synthesis assumes obtaining a solid porous material on the surface of the glass rod and, being characterized...
-
Microstructural Design of Ba0.5La0.5Co0.5Fe0.5O3 Perovskite Ceramics
PublicationBa0.5La0.5Co0.5Fe0.5O3 was synthesized in the solid-state reaction route. The influence of ball milling parameters (such as milling media size, angular velocity, and time), pelletizing pressure, and annealing parameters on the microstructure was studied. The grain size distribution and density or specific surface area changes were investigated in each approach while the individual parameters were changed. The evaluation of BLCF...
-
Effect of sintering temperature on electrochemical performance of porous SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) oxygen electrodes for solid oxide cells
PublicationThis work evaluates the effects of the sintering temperature (800 °C, 900 °C, 1000 °C) of SrTi1-xFexO3-δ (x = 0.35, 0.5, 0.7) porous electrodes on their electrochemical performance as potential oxygen electrode materials of solid oxide cells. The materials were prepared by a solid-state reaction method and revealed the expected cubic perovskite structure. After milling, the powders were characterised by a sub-micrometre particle...
-
Removal of diphenols using pine biochar. Kinetics, equilibrium, thermodynamics, and mechanism of uptake
PublicationThermal pyrolysis synthesized activated biochar from the Pinus elliottii sawdust (PS) at 600° C. The obtained activated biochar (PB600) was used for the removal of three diphenols, catechol (CAT), resorcinol (RES), and hydroquinone (HYD), which are utilized mainly in different industries. The PB600 was characterized by several analytical techniques. The BET surface area of 1473 m2.g−1 and a total pore volume of 0.707 cm3 g−1 was...
-
Partition of friction heat between sliding semispaces due to adhesion-deformational heat generation
PublicationAnalytical expressions of heat-partition coefficient and contact temperatures for two sliding semispaces with account for adhesion-deformational heat generation and contact heat exchange have been obtained. The rate of deformational heat generation is assumed to decay exponentially with increase of distance from the interface. It has been shown that heat-generation configuration and the intensity of contact heat exchange have impact...
-
Improving Thermal Insulation Properties for Prefabricated Wall Components Made of Lightweight Aggregate Concrete with Open Structure
PublicationPorous concrete is commonly used in civil engineering due to its good thermal insulation properties in comparison with normal concrete and high compression strength in comparison with other building materials. An extremely porous concrete, called ‘lightweight aggregate concrete with open structure’ (LAC), is used in some German plants to produce prefabricated wall components. They are used mainly in hall buildings, e.g. supermarkets....
-
Effect of Some Sulphur Additives on The Degradation of 9Cr-1Mo Steel After Its 10 Years Service in The CCR Platforming Unit
PublicationThe work shows the results of the tests of 9Cr-1Mo steel, which was for 10 years operated in the CCR platforming unit in Group Lotos SA in Gdańsk, and then in the laboratory was sulphidised during 166 h at a temperature of 600 °C. Sulphidation was performed in a mixture of H2-H2S gases at the vapour pressure of sulphur 4.1·10-14 atm, so the order of magnitude of vapour pressure was less than that of the dissociation pressure of...
-
Bacterial cellulose in the field of wound healing and regenerative medicine of skin: recent trends and future prospectives
PublicationIn this overview, we focused on the bacterial cellulose (BC) applications, described in recently published scientific papers, in the field of skin regenerative medicine and wound care industry. Bacterial cellulose was proven to be biocompatible with living tissues. Moreover, its mechanical properties and porous structure are considered to be suitable for biomedical applications. It is due to the fact that porous structure of bacterial...
-
Wstępne badania technologii spawania złączy narożnych ze stali niskoweglowej i nierdzewnej o grubości g=6mm i g=10mm
PublicationCelem pracy był dobór parametrów spawania dla spoin narożnych o grubości 6mm i 10mm próbek wykonanych ze stali niskowęglowej S355 i stali nierdzewnej - typu 304 (X6CrNI18-10). Złącza były spawane laserowo, jednostronnie z pełnym przetopem a powierzchnie lica i grani zapewniają uzyskanie szczelności przylegającego elementu uszczelniającego. Próbki zostały dostarczone przez Zleceniodawcę. Próby zostały przeprowadzone na stanowisku...
-
The Influence of Calcium Glycerophosphate (GPCa) Modifier on Physicochemical, Mechanical, and Biological Performance of Polyurethanes Applicable as Biomaterials for Bone Tissue Scaffolds Fabrication
PublicationIn this paper we describe the synthesis of poly(ester ether urethane)s (PEEURs) by using selected raw materials to reach a biocompatible polyurethane (PU) for biomedical applications. PEEURs were synthesized by using aliphatic 1,6-hexamethylene diisocyanate (HDI), poly(ethylene glycol) (PEG), α,ω-dihydroxy(ethylene-butylene adipate) (Polios), 1,4-butanediol (BDO) as a chain extender and calcium glycerolphosphate salt (GPCa) as...
-
Tuning Electrochemical Performance by Microstructural Optimization of the Nanocrystalline Functional Oxygen Electrode Layer for Solid Oxide Cells
PublicationFurther development of solid oxide fuel cell (SOFC) oxygen electrodes can be achieved through improvements in oxygen electrode design by microstructure miniaturisation alongside nanomaterials implementation. In this work, improved electrochemical performance of an La0.6Sr0.4Co0.2Fe0.8O3-d (LSCF) cathode was achieved by the controlled modification of the La0.6Sr0.4CoO3-d (LSC) nanocrystalline interlayer introduced between a porous...
-
Temperature influence on tyre/road noise of selected tyres
PublicationAir and road temperatures substantially affect road vehicle noise emission. The temperature influence on tyre/road noise depends mainly on tyre-road combination. It is different for dense and porous pavements, for bituminous and cement ones. It differs also depending on tyres. The correction procedures for temperature effect are still under consideration and preparation. Tyre/road noise measurements using CPX method were performed...
-
The Use of Direct Shear Test for Optimization of Interlayer Bonding Under a Poroelastic Layer
PublicationPoroelastic Road Surfaces (PERS) are characterised by porous structure with air void content of 20% or higher and stiffness almost 10 times lower than that of a standard asphalt course. Such properties enable noise reduction by up to 12 dB in comparison to SMA 11 mixture. However, the disadvantage of a poroelastic pavement is its low durability, which partially results from delamination from the lower layer. The paper aims to investigate...
-
Organic Acids and Polyphenols Determination in Polish Wines by Ultrasound-Assisted Solvent Extraction of Porous Membrane-Packed Liquid Samples
PublicationIn the near future, Poland is going to have more and more favorable conditions for viticulture. Organic acids and polyphenols are among the most commonly analyzed compounds due to their beneficial properties for human health and their importance in the winemaking process. In this work, a new technique involving ultrasound-assisted solvent extraction of porous membrane-packed liquid samples (UASE-PMLS) was for the first time described...
-
HEAT TRANSFER CHARACTERISTICS OF ENHANCED SHELL AND COIL HEAT EXCHANGER
PublicationIn the paper authors presented their own constructions of shell and tube heat exchangers with intensified heat transfer. The shell and coils heat exchangers are in common use in heat ventilations and air conditioning systems. Those types of recuperators are quite simple constructions, the low value of pressure drops and good conditions of heat transfer. The present study shows an experimental investigation of the heat transfer...
-
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
Journals -
Natural convective heat transfer from isothermalconic
PublicationTheoretical considerations on convective heat transfer from isothermal upward conicalsurfaces have been presented. The physical model of this phenomenon consists of an isothermalcone of inclination angle (φ) between the cone generating line (X) and the radius (R) of the cone base. The angle is a parameter of conical surface which varied from (φ = 0−circular horizontal plate) to (φ = π/2—vertical cylinder) . Onthe basis of Navier–Stokes...
-
HEAT TRANSFER ENGINEERING
Journals -
Ultrasound-Assisted Solvent Extraction of a Porous Membrane Packed Sample for the Determination of Tobacco-Specific Nitrosamines in the Replacement Liquids for E-Cigarettes
PublicationThe content of tobacco-specific nitrosamines (TSNAs) possessing carcinogenic properties has been an important area of research since replacement liquids were introduced for e-cigarettes. A method for determining N′-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N′-nitrosoanatabine (NAT), and N′-nitrosoanabasine (NAB) in replacement liquids for electronic cigarettes was developed using liquid chromatography–tandem...
-
Electrochemical Production of Sodium Hypochlorite from Salty Wastewater Using a Flow-by Porous Graphite Electrode
PublicationThe production of sodium hypochlorite (NaOCl) from salty wastewater using an electrochemical cell has several advantages over other methods that often require hazardous chemicals and generate toxic waste, being more sustainable and environmentally friendly. However, the process of producing sodium hypochlorite using an electrochemical cell requires careful control of the operating conditions, such as the current density, flow rate,...
-
A magnetic stir bar sorbent of metal organic frameworks, carbon foam decorated zinc oxide and cryogel to enrich and extract parabens and bisphenols from food samples
PublicationA porous composite magnetic stir bar adsorbent was fabricated for the extraction and enrichment of parabens and bisphenols from selected beverage samples. The adsorbent comprised a metal organic framework, carbon foam decorated zinc oxide and magnetic nanoparticles embedded in polyvinyl alcohol cryogel. The porous composite stir bar adsorbent could adsorb parabens and bisphenols via hydrogen bonding, π-π and hydrophobic interactions....
-
Raman investigation of the patina layers on Hungarian copper ingots from a fifteenth century shipwreck
PublicationWe report results of the patina study of underwater archeological finding ofmedieval copper objects performed by means of the Raman and complementary spectroscopic techniques. The objects were found submerged in the sea as cargo part of the ship which sunk in the Gulf of Gdańsk in 1408. The excavated collection consists of 230 oval ingots of the size and mass up to about 60 cm and 18 kg (total of 2 tons), respectively. In the Raman...
-
Synthesis of highly crystalline photocatalysts based on TiO2 and ZnO for the degradation of organic impurities under visible-light irradiation
PublicationA TiO2–ZnO binary oxide system (with molar ratio TiO2:ZnO = 8:2) was synthesized by a hydrothermal method, assisted by calcination at temperatures of 500, 600 and 700 °C, using zinc citrate as the precursor of ZnO. The morphology (SEM, TEM), crystalline structure (XRD, Raman spectroscopy), diffuse reflectance spectra (DRS), chemical surface composition (EDXRF), porous structure parameters (low-temperature N2 sorption) and characteristic...
-
Heat transfer and pressure drop characteristics of the silicone-based plate heat exchanger
PublicationThe paper presents an experimental investigation of a silicone based heat exchanger, with passive heat transfer intensification by means of surface enhancement. The main objective of this paper was to experimentally investigate the performance of a heat exchanger module with the enhanced surface. Heat transfer in the test section has been examined and described with precise measurements of thermal and flow conditions. Reported...
-
Development of a new green analytical methodology for the determination of phthalates in single-use babies diapers using ultrasound-assisted extraction and polypropylene porous membrane
PublicationA green extraction strategy was developed and utilized for the extraction and determination of phthalates. The extraction is based on ultrasound-assisted extraction and a polypropylene porous membrane. The Box-Behnken model was performed to optimize the extraction condition. The optimal extraction conditions are 5.5 mL of ethyl acetate, 10 min of extraction time and 55 C for extraction temperature. The developed green extraction...
-
Biocompatibility and bioactivity of load-bearing metallic implants
PublicationThe main objective of here presented research is to develop the titanium (Ti) alloy base composite materials possessing better biocompatibility, longer lifetime and bioactivity behaviour for load-bearing implants, e.g. hip joint and knee joint endoprosthesis. The development of such materials is performed through: modeling the material behaviour in biological environment in long time and developing of new procedures for such evaluation;...
-
Application of shifted Chebyshev polynomial-based Rayleigh–Ritz method and Navier’s technique for vibration analysis of a functionally graded porous beam embedded in Kerr foundation
PublicationPresent study is dealt with the applicability of shifted Chebyshev polynomial based Rayleigh-Ritz method and Navier’s technique on free vibration of Functionally Graded (FG) beam with uniformly distributed porosity along the thickness of the beam. The material properties such as Young’s modulus, mass density, and Poisson’s ratio are also considered to vary along the thickness of the FG beam as per the power-law exponent model....
-
Linear Micropolar Elasticity Analysis of Stresses in Bones Under Static Loads
PublicationWe discuss the finite element modeling of porous materials such as bones using the linear micropolar elasticity. In order to solve static boundary-value problems, we developed new finite elements, which capture the micropolar behavior of the material. Developed elements were implemented in the commercial software ABAQUS. The modeling of a femur bone with and without implant under various stages of healing is discussed in details
-
Possibilities and benefits of a new method of modifying conventional building materials with phase-change materials (PCMs)
PublicationThe paper presents a current study devoted to the optimization of the amount of PCM present within traditional building materials, utilized in this case in hollow-brick walls. Authors focus on proposing an alternative to typical direct addition of PCM to existing building materials: introducing two- and three-component mixtures, based on a porous PCM carrier, which in this case was construction aggregate. Preliminary studies of...
-
Badania połączeń spawanych rurociągu wody pitnej we Włocławku, ang. Welding joints tests in drinking water pipeline.
PublicationCelem badań opisanych w pracy było określenie przyczyn korozji powstałej w strefie wpływu ciepła (SWC) w obwodowych połączeniach spawanych w rurociągu wody pitnej. Materiałem, z którego wykonano rurociąg to stal 304/304L. W obszarze złącza spawanego stwierdzono wżery inicjowane od niezgodności geometrycznych, gdzie mogły gromadzić się osady zwiększające udział chlorków bezpośrednio przy powierzchni rury, promujące tym procesy korozyjne....
-
Protective properties of Al2O3 + TiO2 coating produced by the electrostatic spray deposition method
PublicationMechanical resistance of Al2O3 + TiO2 nanocomposite ceramic coating deposited by electrostatic spray deposition method onto X10CrAlSi18 steel to thermal and slurry tests was investigated. The coating was produced from colloidal suspension of TiO2 nanoparticles dispersed in 3 wt% solution of Al2(NO3)3, as Al2O3 precursor, in ethanol. TiO2 nanoparticles of two sizes, 15 nm and 32 nm, were used in the experiments. After deposition,...
-
A hierarchical porous composite magnetic sorbent of reduced graphene oxide embedded in polyvinyl alcohol cryogel for solvent‐assisted‐solid phase extraction of polycyclic aromatic hydrocarbons
PublicationA hierarchical porouscomposite magnetic sorbent was fabricated and applied tothe dispersive solvent-assisted solid-phase extraction of five polycyclic aromatichydrocarbons. A sorbent was first prepared by incorporating graphene oxide,calcium carbonate, and magnetite nanoparticles into a polyvinyl alcohol cryo-gel. The graphene oxide was converted to reduced graphene oxide using ascorbicacid and a hierarchical porous structure was...
-
Ultrasound assisted solvent extraction of porous membrane-packed samples followed by liquid chromatography-tandem mass spectrometry for determination of BADGE, BFDGE and their derivatives in packed vegetables
PublicationThe problem of the presence of trace organic pollutants in food is of growing importance due to increasing awareness about their impact on newborns, infants and adults of reproductive age. Despite the fact that packaged food products offer many advantages, packaging can be a source of contamination for stored food. Thus, monitoring such pollution in food is of high importance. In this work, a novel methodology based on the solvent...
-
Fabrication of Composite Polyurethane/Hydroxyapatite Scaffolds Using Solvent-Casting Salt Leaching Technique
PublicationScaffolds are porous three-dimensional structures which are used to fill bone losses and make them possible to cells to grow. Many different structural and biological properties are required from them: porosity, mechanical strength and biocompability. The present research is aimed at development of composite polyurethane/hydroxyapatite scaffolds by using the solvent-casting salt leaching method. The SEM examinations were applied...
-
Empirical Relationship Describing Total Convective and Radiative Heat Loss in Buildings
PublicationOn the basis of theoretical considerations of convective-radiative heat transfer, a relationship was developed enabling the total convective and radiative heat flux QC+R emitted from any object at tw and its surroundings at t∞ to be calculated from known values of the surface temperature of such an object, i.e., the known temperature difference Δt=tw - t∞ and average air temperature Tav. This relationship is applied to thermal...