Filtry
wszystkich: 2872
wybranych: 2190
-
Katalog
- Publikacje 2190 wyników po odfiltrowaniu
- Czasopisma 18 wyników po odfiltrowaniu
- Osoby 27 wyników po odfiltrowaniu
- Wynalazki 1 wyników po odfiltrowaniu
- Projekty 2 wyników po odfiltrowaniu
- Aparatura Badawcza 2 wyników po odfiltrowaniu
- Kursy Online 54 wyników po odfiltrowaniu
- Wydarzenia 3 wyników po odfiltrowaniu
- Dane Badawcze 575 wyników po odfiltrowaniu
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: laboratoryjny material odniesienia
-
Geometrically nonlinear analysis of shells - Benchmark problems for Autocad Robot Analysis Professional
PublikacjaThe aim of this work is to verify the suitability of commercial engineering software for geometrically nonlinear analysis of shells. This paper deals with the static, geometrically nonlinear analysis of shells made of an isotropic material. The Finite Element Method (FEM) is chosen to solve the problem. The results of the commercial software Autocad Robot Structural Analysis Professional (ARSAP) are compared with the litera-ture...
-
Fatigue behaviour of SLM maraging steel under variable-amplitude loading
PublikacjaOne of the most challenging issues for additive manufactured materials is fatigue endurance. Engineering components often operate under complex, variable amplitude loadings, in which existing technological imperfections promote fatigue cracks growth and damage of elements eventually. In this study the effects of different variable-amplitude strain levels on fatigue life, 18Ni300 steel was tested. The work presents various behaviours...
-
3D buckling analysis of a truss with horizontal braces
PublikacjaThe present research is devoted to the study of out-of-plane buckling of a truss with horizontal braces. The truss is a model of real roof truss scaled by factor ¼. A linear buckling and a non-linear analysis with geometric and material nonlinearity were carried out. The truss buckling and limit load for different stiffnesses and number of braces are found. Numerical analysis are verified by experiment. Threshold bracing stiffness...
-
TESTING CONTRACTION AND THERMAL EXPANSION COEFFICIENT OF CONSTRUCTION AND MOULDING POLYMER COMPOSITES
PublikacjaThe paper presents results of systematic tests of contraction and thermal expansion coefficients of materials based on polymer composites. The information on the above material properties is essential both at the design stage and during the use of finished products. Components for the samples were selected in such a way as to represent typical materials used for production of construction and moulding elements. The performed tests...
-
Experimental study on polymer mass used to repair damaged structures
PublikacjaA new method of repairing damaged structures by injecting the cracks with specially designed polymer mass (flexible two-component grout based on polyurethane resin) has been recently proposed. The technique is mainly dedicated to damaged masonries, especially historical structures where minimum intervention is permitted. The cracks are filled with the special injection, forming the flexible joints bonding the disrupted structural...
-
Entire fracture surface topography parameters for fatigue life assessment of 10H2M steel
PublikacjaIn this paper, the entire fracture surface approach was used to assess an effect of 280,000 h of exploitation under internal pressure of 2.9 MPa and high temperature of 540 °C on the fatigue response of 10H2M (10CrMo9–10) power engineering steel. The mechanical testing was carried out on the hourglass specimens produced from the as-received, unused pipeline and the same material after long-time exploitation. The uniaxial tensile...
-
Integration of antifouling properties into epoxy coatings: a review
Publikacjahe need for nontoxic antifouling coatings has encouraged material scientists to develop a class of organic coatings for diverse applications. As a versatile thermosetting resin and well known for coating application, antifouling characteristics have been integrated into epoxy along with anticorrosion and adhesive functions. Accordingly, both micro- and macro-biofoulings have been successfully controlled by using epoxy-based antifouling...
-
Emission of 1.3–10 nm airborne particles from brake materials
PublikacjaOperation of transport vehicle brakes makes a significant contribution to airborne particulate matter in urban areas, which is subject of numerous studies due to the environmental concerns. We investigated the presence and number fractions of 1.3–10 nm airborne particles emitted from a low-metallic car brake material (LM), a non-asbestos organic car brake material (NAO) and a train brake cast iron against a cast iron. Particles...
-
Quantitative assessment of the influence of tensile softening of concrete in beams under bending by numerical simulations with XFEM and cohesive cracks
PublikacjaResults of the numerical simulations of the size effect phenomenon for concrete in comparison with experimental data are presented. In-plane geometrically similar notched and unnotched beams under three-point bending are analyzed. EXtended Finite Element Method (XFEM) with a cohesive softening law is used. Comprehensive parametric study with the respect to the tensile strength and the initial fracture energy is performed. Sensitivity...
-
Analytical Methods for Causality Evaluation of Photonic Materials
PublikacjaWe comprehensively review several general methods and analytical tools used for causality evaluation of photonic materials. Our objective is to call to mind and then formulate, on a mathematically rigorous basis, a set of theorems which can answer the question whether a considered material model is causal or not. For this purpose, a set of various distributional theorems presented in literature is collected as the distributional...
-
Role of surface recombination in perovskite solar cells at the interface of HTL/CH3NH3PbI3
PublikacjaIn order to achieve the highest performance of organometal trihalide perovskite solar cells, it is required to recognize the dominant mechanisms which play a key role in a perovskite material. In the following studies, we have focused on the interfacial recombination between the hole transporting layer (HTL) and the perovskite CH3NH3PbI3 in solar cell devices with p–i–n architecture. It has been shown that Cu:NiOx : used as HTL...
-
Ongoing Progress on Pervaporation Membranes for Ethanol Separation
PublikacjaEthanol, a versatile chemical extensively employed in several fields, including fuel production, food and beverage, pharmaceutical and healthcare industries, and chemical manufacturing, continues to witness expanding applications. Consequently, there is an ongoing need for cost-effective and environmentally friendly purification technologies for this organic compound in both diluted (ethanol-water–) and concentrated solutions (water-ethanol–)....
-
Cyclic behaviour modelling of additively manufactured Ti-6Al-4V lattice structures
PublikacjaThe present work is concerned with the numerical modelling of the cyclic behaviour of Ti-6Al-4V lattice structures. In the study, diamond structures of titanium alloy produced by the additive laser powder bed fusion (LPBF) method with different degrees of relative density were used. Realistic geometric models of the studied mesostructures were generated using computed microtomography, taking into account the imperfections of the...
-
The lanthanide influence on selected properties of BaLnCo2O6-δ
PublikacjaThe subject of research of this dissertation are cobalt oxides with a double perovskite structure with a general formula BaLnCo2O6-δ, where Ln stands for La, Pr, Nd, Sm, Gd, Tb, Dy. The aim of the study was to verify the ability of these materials to form the protonic defects, as well as to identify the factors determining this ability. As part of the work, materials from the proposed group were synthesised and characterized. To...
-
Modelling tunnelling-induced deformation in stiff soils with a hyperelastic–plastic anisotropic model
PublikacjaIn this paper, the tunnelling-induced deformation in anisotropic stiff soils is analysed using FE modelling. The influence of material description is investigated rather than an advanced simulation of the tunnelling method. A new hyperelastic– plastic model is proposed to describe the anisotropic mechanical behaviour of stiff highly overconsolidated soil. This model can reproduce the superposition of variable stress-induced anisotropy...
-
Influence of hydrochloric acid concentration and type of nitrogen source on the electrochemical performance of TiO2/N-MoS2 for energy storage applications
PublikacjaIn this work, nitrogen-doped molybdenum sulfide was directly deposited on titanium dioxide nanotubes substrate (TiO2/N-MoS2) during hydrothermal synthesis. The study focuses on the influence of hydrochloric acid concentration used for the synthesis, with the results indicating its essential role in thioacetamide hydrolysis and thus in the effectiveness of the N-MoS2 deposition. The electrode material itself is characterized by...
-
Synthesis and characterization of novel renewable polyesters based on 2,5-furandicarboxylic acid and 2,3-butanediol
PublikacjaNovel polyesters from 2,5-furandicarboxylic acid or 2,5-dimethyl-furandicarboxylate and 2,3-butanediol have been synthesized via bulk polycondensation catalyzed by titanium (IV) n-butoxide, tin (IV) ethylhexanoate, or zirconium (IV) butoxide. The polymers were analyzed by size exclusion chromatography, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser ionization-desorption...
-
Preparation and Characterization of Films Based on Disintegrated Bacterial Cellulose and Montmorillonite
PublikacjaThe food packaging materials from natural polymers including polysaccharides offer an ecologically important alternative to commonly used synthetic, non-biodegradable counterparts. The purpose of this work was to modify of bacterial cellulose (BC) leading to the improvement of its functional properties in terms of use as a food packaging material. Effects of disintegration of BC and addition of montmorillonite (MMT) on its water...
-
Compliance tests of the polymer layers used as hydrodynamic bearing coatings
PublikacjaOperational experience and scientific investigations results showed that polymer lined hydrodynamic bearings can withstand more severe operating conditions compared than white metal bearings. PTFE and PEEK-based coatings are the most frequently used as Babbitt alternatives. Both polymers differ significantly from the each other in material properties. According to catalogue data compression modulus of PTFE, it is about an order...
-
A study of the kinetics of bismuth telluride synthesis by an oxide reduction method
PublikacjaThe kinetics of a reduction of bismuth and tellurium oxides in a hydrogen atmosphere, leading to the formation of thermoelectric bismuth telluride is investigated. The evaluation of the reaction kinetics was based on a thermogravimetric analysis performed in non-isothermal conditions. A non-parametric analysis method and the Friedman method were used for the evaluation of the data. Additionally, for a better understanding of the...
-
Degradable poly(ester-ether) urethanes of improved surface calcium deposition developed as novel biomaterials
PublikacjaBones, which are considered as hard tissues, work as scaffold for human body. They provide physical support for muscles and protect intestinal organs. Percentage of hard tissues in human body depends on age, weight, and gender. Human skeleton consists of 206 connected bones. Therefore, it is natural that the hard-tissue damage such as fractures, osteoporosis, and congenital lack of bone may appear. The innovative way of bone healing...
-
Effect of selective laser treatment on initiation of fatigue crack in the main part of an undercarriage drag strut
PublikacjaThis paper presents the results of material characterization and a fatigue test conducted for a laser-re-melted drag strut used in an aircraft landing gear. The drag strut was re-melted with a CO2 laser beam. Eight re-melted paths were made in the form of spiral lines along the axis of the drag strut. Next, the drag strut was subjected to variable loads on a testing machine simulating loads occurring when an aircraft lands. The...
-
Assessment of the usefulness of bacterial cellulose produced by Gluconacetobacter xylinus E25 as a new biological implant
PublikacjaBionanocellulose (BNC) is a clear polymer produced by the bacterium Gluconacetobacter xylinus. In our current study, “Research on the use of bacterial nanocellulose (BNC) in regenerative medicine as a function of the biological implants in cardiac and vascular surgery”, we carried out material analysis, biochemical analysis, in vitro tests and in vivo animal model testing. In stage 1 of the project, we carried out physical and...
-
Comparison of Surface Quality and Tool-Life of Glulam Window Elements after Planing
PublikacjaThe quality of the surface of wooden elements, that have been planed, has a crucial importance in the whole production process, since the obtained effects affect the quality of wooden surface after fi nishing (painting). The occurrence of defects is usually the reason for qualifying a workpiece as scrap or for requiring additional work. This paper presents the selected results of research of the effect of the cutting tool wear...
-
Nonlinear electrical properties of glass-ceramics nanocomposites containing ferroelectric nanocrystallites of Bi2VO5.5
PublikacjaNonlinear A.C. impedance measurements were conducted in the 50BiV-50SrBAlO nanocomposite as a function of frequency, temperature and A.C. voltage. This material is ferroelectric below temperature of 730 K, and above 730 K is a good ion-conductor. For this nanocomposite a low A.C. voltage of 1 V rms is enough to observe high nonlinearities. The origin of these nonlinear effects depends on the temperature and frequency. In the high...
-
New Polymeric Materials for Solid Phase Extraction
PublikacjaSolid phase extraction (SPE) is a popular sample preparation technique, which can be applied directly in gas–solid phase and liquid–solid phase, or indirectly to solid samples by using, e.g., thermodesorption with subsequent chromatographic analysis. Although SPE can be described as a physical extraction process involving a liquid phase and a solid phase, the increased use of packed sorbent formats seems to have led to a bias toward...
-
Investigation of the Few‐Layer Black Phosphorus Degradation by the Photonic Measurements
PublikacjaFew-layer black phosphorus (FLBP) is a 2D material that gains worldwide interest for its possible applications, mainly in electronics and optoelec-tronics. However, as FLBP is prone to a degradation process under envi-ronmental conditions, there is a need for a monitoring method allowing investigation of its surface quality. Among many techniques, optoelectronic ones have unique advantages of fast response, non-contact, and non-invasive...
-
Variability of physico-chemical parameters in precipitation in Poland (1996-1999)
PublikacjaW publikacji przedstawiono wyniki badań przeprowadzonych w latach 1996-1999, dotyczących analizy próbek osadów atmosferycznych zebranych w trzech miejscach pobierania próbek. Zostały one porównane z wynikami otrzymanymi w pięciu innych miejscach na terenie Polski, rozmieszczonych zarówno na terenach objętych ochroną, takich jak parki narodowe, jak również narażonych na silny wpływ zanieczyszczeń pochodzących z aglomeracji miejskich...
-
Ekonomiczne aspekty zastosowania techniki Mobilnych Pomiarów Satelitarnych przy regulacji osi toru
PublikacjaOd 2009 roku interdyscyplinarny zespół naukowy Politechniki Gdańskiej i Akademii Marynarki Wojennej (a obecnie Akademii Morskiej w Gdyni) rozwija technikę Mobilnych Pomiarów Satelitarnych toru kolejowego. Technika ta polega na objeździe trasy ciągnikiem szynowym z przyczepą (wagonem-platformą) lub wózkami, z zainstalowanymi na tych pojazdach odbiornikami sygnałów satelitarnych. Umożliwia ona precyzyjne określenie współrzędnych...
-
Non-linearity of multibody dynamic equations with respect to Lagrange multipliers: application to railway dynamics
PublikacjaPraca koncentruje się na dynamice układów wieloczłonowych z zamkniętymi łańcuchami członów. Głównym punktem zainteresowania jest modelowanie układów z występującymi nieliniowymi zależnościami opisującymi wpływ siły mnożników Lagrange'a na dynamikę układu (nieliniowe modele siły tarcia.). Aby zbudować model dynamiki układu zawierającego zamknięte łańcuchy członów, wspomniane łańcuchy są "rozcinane" i budowana jest struktura drzewa...
-
Szkodliwe dla zdrowia izomery trienowych kwasów tłuszczowych w mleku początkowym i następnym do żywienia niemowląt
PublikacjaZbadano zawartość kwasów tłuszczowych zawierających układ trzech sprzężonych wiązań podwójnych TCFA, szkodliwych dla zdrowia produktów oksydacji lipidów, w tłuszczu wolnym i w tłuszczu związanym mleka początkowego MP i następnego MN do żywienia niemowląt (5-ciu różnych producentów, łącznie 17 produktów). Liczbowo zawartość TCFA wyrażono umownie jako parametr K [%] będący stosunkiem absorbancji układu trzech sprzężonych wiązań podwójnych...
-
Wydajność przetwarzania żądań usług uwarunkowanych czasowo realizowanych w sieci IMS/NGN
PublikacjaW rozprawie dokonano przeglądu stanu implementacji koncepcji IMS/NGN, a także modeli systemów obsługi z oczekiwaniem pod kątem zastosowania dla serwerów i łączy w modelu analitycznym wielodomenowej sieci IMS/NGN. Przedstawiono założenia dla tego modelu oraz metodologię obliczeń i analizy wyników: średnich czasów E(CSD) zestawiania i E(CDD) rozłączenia połączenia dla scenariuszy połączeń zakończonych sukcesem. Opisano założenia,...
-
Pozwolić odejść, czyli... Granice interwencji
PublikacjaCelem tekstu jest zwrócenie uwagi na problem ostatecznej granicy interwencji konserwatorskich wobec zabytków architektury w kontekście holistycznej koncepcji ochrony dziedzictwa. Tekst adresowany jest do polskich czytelników ze względu na szczególne odniesienia do sytuacji polskiego systemu ochrony dziedzictwa. Choć architektura należy do sfery sztuk użytkowych, większość budynków nie powstawała...
-
Zależność pomiędzy wielkością przedsiębiorstwa a strukturą aktywów
PublikacjaCelem artykułu jest przedstawienie zróżnicowania struktury aktywów pomiędzy małymi, średnimi oraz dużymi przedsiębiorstwami, z uwzględnieniem czynnika specyfiki branżowej prowadzonej działalności gospodarczej. W przeprowadzonych badaniach wykorzystano w głównej mierze narzędzia analizy strukturalnej, statystyki opisowej oraz nieparametrycznego wnioskowania statystycznego. Z przeprowadzonych badań wynika, że wskaźniki struktury...
-
Magnetic properties of α-KCoPO4 compound with a chiral polar crystal structure
PublikacjaWe have obtained polycrystalline samples of a metastable α variant of KCoPO4 by low temperature (350–400 °C) solid state metathesis reaction of potassium oxalate and ammonium cobalt orthophosphate. The material crystallizes in a polar chiral structure (sg. P63, no. 173). Measurements of magnetic properties reveal antiferromagnetic interactions and no ordering observed down to T = 1.9 K, well below the Weiss temperature |Θcw| =...
-
THE POSSIBILITY OF USE OF LASER-MODIFIED Ti6Al4V ALLOY IN FRICTION PAIRS IN ENDOPROSTHESES
PublikacjaThe purpose of this paper is to show results of laser treatment at cryogenic conditions of the Ti6Al4V alloy used for orthopedic applications. That modification process ought to bring beneficial changes of microstructure and residual stresses in the surface layer. The paper presents the abrasive wear of the base and laser remelted material in association with ceramics Al2O3. Despite the surface cracking after laser treatment the...
-
Numerical and Analytical Investigation of Aluminium Bracket Strengthening
PublikacjaThis paper focuses on an analytical and numerical investigation of aluminium brackets used to fasten light-weight curtain walls to building facilities. The authors propose a solution to increase the load capacity of aluminium brackets by means of additional cover plates (straps). This paper also includes a short survey of literature and material properties concerning the EN AW-6060 T6 aluminium alloy. This paper suggests an initiation...
-
Modelling of concrete behaviour in uniaxial compression and tension with DEM.
PublikacjaW artykule omowiono wyniki modelowania betonu podczas jednoosiowego sciskania i rozciagania stosujac metode elementów dyskretnych. Beton zostal opisany jako material 3-fazowy (kruszywo, zaprawa cementowa i strefy kontaktu). Szczegolna uwage zwrocono na zjawiska mikro-strukturalne na poziomie kruszywa (lancuchy sil, wiry, obroty ziaren). Wyniki numeryczne zostaly porownano z wynikami badan doswiadczalnych.
-
Influence of e-beam irradiation on poly(aliphatic/aromatic-ester) multiblock copolymers used as biomaterials
PublikacjaThe use of polymers became more relevant in medical applications for the versatility in processing and enhanced material properties of polymers. In order to be suitable as a biomaterial, it is of medical importance that these polymers are biocompatible and do not elicit negative responses from the body after implantation. Furthermore during the course of usage under load-bearing conditions, these biomaterials must sustain dynamical...
-
Influence of thermal effects on mechanical properties of PVDF-coated fabric
PublikacjaThis paper describes the method of laboratory tests necessary for identification of temperature influence on mechanical properties of polyvinylidene fluoride-coated polyester fabric often used for tensile structures. Two nonlinear model descriptions are investigated. The first one is based on the piece-wise linear relations between stress and strain and the second one on the Murnaghan model of solid behavior. This paper is proposed...
-
3D Buckling Analysis of a Truss with Horizontal Braces
PublikacjaThe present research is devoted to the study of out–of–plane buckling of a truss with horizontal braces. The truss is a model of real roof truss scaled by factor 1=4. A linear buckling and a non–linear analysis with geometric and material non–linearity were carried out. The truss buckling and limit load for different stiffnesses and number of braces are found. Numerical analysis are verified by experiment. Threshold bracing stiffness condition...
-
Wpływ drążenia pionowego w silikatowych elementach murowych na nośność kotew wklejanych
PublikacjaThe article is showing results of measurements of the effectiveness of the assembly anchor of inmates glued in in sunk vertically lime-sandy blocks. Examinations were performed for cases of the assembly anchor in different fragments of blocks: in part fullwall, in an axis of symmetry and on the edge of the aperture vertical. An influence of the location of places of settling was examined anchor to the way of the forming of uniting...
-
Nonlinear FEM analysis of irregular shells composed of fiber metal laminates
PublikacjaThe paper deals with the analysis of failure initiation in shells made of Fiber Metal Laminates (FML). The elas-tic material law for orthotropic lamina is stated accounting for asymmetric in-plane stress and strain measures. The asymmetry results from the employed general nonlinear 6-field shell theory where the generalized dis-placements involve the translation and the proper rotation field. The novelty of the presented results...
-
Numerical Modelling of Shear Localization in Granular Bodies using MPM and Non-local Hypoplasticity
PublikacjaThe paper deals with modelling of shear localization in granular bodies by means of an enhanced hypoplastic constitutive model and material point method (MPM). The calculations were carried out for plane strain compression of non-cohesive sand. In order to properly capture the width and inclination of shear zones, the constitutive model was enriched by a characteristic length of micro-structure by means of a non-local theory....
-
Conversion of waste biomass to designed and tailored activated chars with valuable properties for adsorption and electrochemical applications
PublikacjaWaste biomass, a renewable energy source, is inexpensive material that has great potential in sorp-tion and electrochemical application. The selected waste materials (corncobs, coconut shells, wal-nuts, and pistachio husks) allow to close the production cycle and enable material recycling, which are important aspects in the hierarchy of waste management. The proposed methodology for pro-duction and activation of biochars can be...
-
Review on robust laser light interaction with titania – Patterning, crystallisation and ablation processes
PublikacjaTitanium dioxide is regarded as a very promising semiconducting material that is widely applied in many everyday-use products, devices, and processes. In general, those applications can be divided into energy or environmental categories, where a high conversion rate, and energy and power density are of particular interest. Therefore, many efforts are being put towards the elaboration of novel production routes, and improving the...
-
Fermentative Conversion of Two-Step Pre-Treated Lignocellulosic Biomass to Hydrogen
PublikacjaFermentative hydrogen production via dark fermentation with the application of lignocellulosic biomass requires a multistep pre-treatment procedure, due to the complexed structure of the raw material. Hence, the comparison of the hydrogen productivity potential of different lignocellulosic materials (LCMs) in relation to the lignocellulosic biomass composition is often considered as an interesting field of research. In this study,...
-
A continual model of a damaged medium used for analyzing fatigue life of polycrystalline structural alloys under thermal–mechanical loading
PublikacjaThe main physical laws of thermal–plastic deformation and fatigue damage accumulation processes in polycrystalline structural alloys under various regimes of cyclic thermal–mechanical loading are considered. Within the framework of mechanics of damaged media, a mathematical model is developed that describes thermal–plastic deformation and fatigue damage accumulation processes under low-cycle loading. The model consists of three...
-
Recycling of Photovoltaic Solar Cells and Modules - Te State - Of - Art
PublikacjaIn comparison to other energy producing techniques, photovoltaics (PV) is one of the most promising options: no emission of any matter into the environment during operation; extremely long operation period (estimated average: 25 years), minimum maintenance, robust technique, aesthetic aspects. The use of photovoltaics is rapidly increasing, and the respective market is developing accordingly. Although PV manufacturing equipment...
-
CURRENT TRENDS IN RECYCLING OF PHOTOVOLTAIC SOLAR CELLS AND MODULES WASTE
PublikacjaIn comparison to other energy producing techniques, photovoltaics (PV) is one of the most promising options: no emission of any matter into the environment during operation; extremely long operation period (estimated average: 25 years), minimum maintenance, robust technique, aesthetic aspects. The use of photovoltaics is rapidly increasing, and the respective market is developing accordingly. Although PV manufacturing equipment...