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Search results for: flexible polyurethane foams
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One-Step Synergistic Effect to Produce Two-Dimensional N-Doped Hierarchical Porous Carbon Nanosheets for High-Performance Flexible Supercapacitors
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Ciprofloxacin – Modified Degradable Hybrid Polyurethane-Polylactide Porous Scaffolds Developed for Potential Use as an Antibacterial Scaffold for Regeneration of Skin
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Characterization of Highly Filled Glass Fiber/Carbon Fiber Polyurethane Composites with the Addition of Bio-Polyol Obtained through Biomass Liquefaction
PublicationThis work aims to investigate the process of obtaining highly filled glass and carbon fiber composites. Composites were manufactured using previously obtained cellulose derived polyol, polymeric methylene diphenyl diisocyanate (pMDI). As a catalyst, dibutyltin dilaurate 95% and Dabco® 33-LV were used. It was found that the addition of carbon and glass fibers into the polymer matrix causes an increase in the mechanical properties...
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Enzymatic cleavage of specific dipeptide conjugated with ferrocene as a flexible ultra-sensitive and fast voltammetric assay of matrix metalloproteinase-9 considered a prognostic cancer biomarker in plasma samples
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Na3PO4 assistant dispersion of nano-CaCO3 template to enhance electrochemical interface: N/O/P co-doped porous carbon hybrids towards high-performance flexible supercapacitors
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Zastosowanie elementów "węzłowych" do budowy modelu 3D cewki giętkiej w programie polowym OPERA 3D = Application of "nodal" elements for creation of a 3D model of a flexible coil in the program Opera 3D
PublicationNiniejsza praca jest kontynuacją serii artykułów dotyczących modelowania 3D uzwojenia maszyn elektrycznych z cewkami giętkimi. Istotnym problemem dotyczącym modelowania takiego uzwojenia jest zmienność kształtu przekroju poprzecznego zwłaszcza w części czołowej. Powoduje to problemy w utworzeniu uzwojenia bez konfliktów wymiarowych (nie przenikanie się wierzchołków, przyleganie boków cewek, odpowiednie położenie). Niektóre programy...
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Polyester-urethanes modified with gelatine for tissue scaffolds
PublicationNovel aliphatic PU foams, modified with gelatine, were obtained in a one-step polymerization process. Hard segments were obtained from 1,6-hexamethylene diisocyanate (HDI) and chain extenders 1,4-butanediol (BDO) or 2-(2-(2-hydroxyethoxy)ethoxy)ethanol (TG), soft segments were obtained from poly(ethylene-buthylene adipate) (EBO) polyol. We examined the PU foams for their sorption capability in canola oil, saline (0.9% NaCl water...
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Thermoplastic elastomer filaments and their application In 3D printig
PublicationThe paper provides an overview on the materials used in the 3D printing technology (the Polish and foreign market) with a particular focus on flexible filaments and their possible application in the industry. There are described the techniques of 3D printing and modern filaments available on the market. There is observed the increase of interest in the production of products from filaments based on thermoplastic elastomers (TPE),...
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Cast polyurethanes obtained from reactive recovered polyol intermediates via crude glycerine decomposition process
PublicationIn this work, the possibility of applying intermediates from polyurethane waste recycling in polyurethane synthesis was presented. Polyurethanes were synthesised in a two-step method using a mixture of petrochemical polyol and glycerolysate, used as a reactive component, 4,4-diphenylmethane diisocyanate (MDI) and 1,4-buthanediol (BD). Glycerolysates were produced during decomposition of polyurethane elastomer by crude glycerine...
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Nowe monomery pochodzenia roślinnego w syntezie termoplastycznych elastomerów poliuretanowych
PublicationJak dotychczas w syntezie termoplastycznych elastomerów poliuretanowych (TPU) są powszechnie wykorzystywane surowce pochodzenia petrochemicznego. Sytuacja jednak zmienia się dynamicznie i w wielu gospodarkach świata widoczne są już trendy, polegające na coraz większym wykorzystaniu substancji pochodzenia roślinnego w produkcji surowców, np. glikoli, izocyjanianów czy polioli, jako zamienników analogów syntetycznych. Praca obejmuje...
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PU Polymers, Their Composites, and Nanocomposites: State of the Art and New Challenges
PublicationThe chapter is a review of the polyurethane(PU)-based composites and nanocomposites. The chapter details different components in the manufacturing of PU polymers, composites, and nanocomposites. The different types of glycols, isocyanates, and catalysts that are used for the synthesis of different polyurethanes are discussed. The applications and specialties of polyurethane composites and nanocomposites are also elaborated on.
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Development of polyurethanes for bone repair
PublicationThe purpose of this paper is to review recent developments on polyurethanes aimed at the design, synthesis, modifications, and biological properties in the field of bone tissue engineering. Different polyurethane systems are presented and discussed in terms of biodegradation, biocompatibility and bioactivity. A comprehensive discussion is provided of the influence of hard to soft segments ratio, catalysts, stiffness and hydrophilicity...
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Experimental Study on Dynamics of Wooden House Wall Panels with Different Thermal Isolation
PublicationWood frame buildings are very popular in regions that are exposed to different dynamic excitations including earthquakes. Therefore, their seismic resistance is really important in order to prevent structural damages and human losses. The aim of the present paper is to show the results of experimental tests focused on the dynamic response of wall panels of a wooden frame building with thermal isolation made of mineral wool and...
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Allocation of tools to machines in a flexible machining cell. W: Computerintegrated manufacturing. Advanced design and management. Ed.: B. Skołud, D. Krenczyk. Warszawa: Wydaw. Nauk.-Tech.**2003 s. 486-493, 5 rys. 2 tabl.bibliogr. 10 poz. Przydział narzędzi do obrabiarek w elastycznym gnieździe obróbkowym.
PublicationPrzedstawiono zagadnienia modelowania i analizy przepływu narzędzi w wielo-maszynowym elastycznym gnieździe, zorientowanym na wytwarzanie przedmiotów klasy korpus. Zaproponowano oryginalną metodę i algorytmy współbieżnego sze-regowania zadań produkcyjnych i przydziału narzędzi w warunkach ograniczono-ści zasobów systemu. Wybrane strategie przydziału operacji technologicznych i adekwatnych zestawów narzędziowych poddano analizie...
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Antibacterial polyurethanes, modifed with cinnamaldehyde, as potential materials for fabrication of wound dressings
PublicationThe epidermis is a skin layer, which protects an organism from the different factors of external environment. Therefore, the fast and effective regeneration of epidermis is important. Potential materials used for epidermis regeneration may be polyurethane scaffolds in form of the thin permeable layers. One and main disadvantage of such polyurethane scaffolds are their lack of antibacterial and antifungal properties. The great proposition...
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Influence of Surface-Modified Montmorillonite Clays on the Properties of Elastomeric Thin Layer Nanocomposites
PublicationIn recent years, polyurethane nanocomposites have attracted more attention due to the massive demand for materials with increasingly exceptional mechanical, optical, electrical, and thermal properties. As nanofillers have a high surface area, the interaction between the nanofiller and the polymer matrix is an essential issue for these materials. The main aim of this study is to validate the impact of the montmorillonite nanofiller...
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublicationThe mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete Element Methods....
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Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study
PublicationAbstract: The mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also on the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete...
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Process zone in the Single Cantilever Beam under transverse loading. - Part II: Experimental
PublicationThis paper describes an experimental arrangement to evaluate stress/strain fields in the process zone of asymmetric adhesively bonded joints. A transparent polycarbonate flexible beam was bonded to an aluminium alloy rigid block with an epoxy adhesive in a Single Cantilever Beam (SCB) configuration. The flexible adherend was loaded in the direction parallel to the initial crack front at constant rate. To monitor strains induced...
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MODAL ANALYSIS OF REAL TIMBER FRAME HOUSES WITH DIFFERENT INSULATION MATERIALS
PublicationThe aim of this article is to present the results of a numerical modal analysis of two actual structures of timber frame buildings and the different behaviour due to the used insulation material. One model of the timber structure was filled with mineral wool, while the other with polyurethane foam. During the modal analysis, eigenvalues for both models have been determined. The results of the analysis clearly show the increase...
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Experimental Study on Pounding between Structures during Damaging Earthquakes
PublicationMutual pounding between structures during earthquakes may cause serious structural damage. The aim of this paper is to show the results of a shaking table experimental study focused on pounding between structures in series under several earthquake excitations. The experiments were performed using three tower models with different configurations and different gap distances between them. In the first stage of the study, one rigid...
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Prediction of the fatigue lifetime of PUR structural elements using a combined experimental-numerical approach
PublicationThis paper presents a method for estimating the fatigue life of polyurethane elastomeric components. A rubber replacement - polyurethane of hardness 80ShA commonly used in vibration damping systems, for example, in motor vehicle suspensions, was used for the study. A metal-rubber bushing component was selected for analysis, and numerical analysis was carried out along with a fatigue model proposal based on a modification of the...
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Bio polyetherurethane composites with high content of natural ingredients: hydroxylated soybean oil based polyol, bio glycol and microcrystalline cellulose
PublicationIn our study, we focused on obtaining bio-polyurethane composites using bio-components such as bio glycol, modified natural oil-based polyol, and microcrystalline cellulose (MCC). The pre-polymer method was used to prepare the bio polyurethane matrix. Prepolymer was synthesized using 4,4’-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 50 wt.% of commercial polyether and 50 wt.% of hydroxylated soybean oil (H3)....
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Timber Frame Houses with Different Insulation Materials - Seismic Analysis
PublicationThe aim of this article is to present results of a dynamic numerical analysis focused on the response of two timber frame building structures exposed to seismic excitations. The first structure was insulated with mineral wool, while the second one with polyurethane foam. Specifications and technology involved in the models' construction are based on the previously conducted experimental study, upon which numerical structural models...
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Recycling of Polyurethanes
PublicationPolyurethane waste can be recycled by mechanical methods (i.e., grinding and applying as a filler or pressing with a bonding agent) and chemical methods (mainly by e.g., glycolysis, hydrolysis, or aminolysis). There is also possibility to the recover energy from polyurethanes waste (by incineration, gasification, and pyrolysis).
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Preparation, characterization, and manufacturing of new polymeric materials for 3D printing for medical applications
PublicationThis work concerns the synthesis, formation, and characteristics of new filaments for 3D printing in FDM™/FFF technology for medical purposes. Two types of filaments were developed, i.e. degradable polyurethane and biodegradable polylactide-starch. The influence of the 3D printing process on selected filament properties was investigated. A detailed analysis of the filament formation process by the extrusion method was carried out,...
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ESTYMACJA WSPÓŁCZYNNIKÓW SZTYWNOŚCI ZAMOCOWANIA PODATNEGO PRZEDMIOTU OBRABIANEGO NA STOLE FREZARKI
PublicationW pracy przedstawiono metodę estymacji współczynników sztywności Elementów Sprężystych (ES) modelujących zamocowanie podatnego wielkogabarytowego przedmiotu obrabianego na stole frezarki. Proponowana metoda bazuje na algorytmie optymizacji za pomocą roju cząstek (ang. Particle Swarm Optimization), który pozwala na uzyskanie dobrej zgodności (aktualizacji) modelu Metody Elementów Skończonych (MES) z modelem pochodzącym z identyfikacji...
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Timber frame houses resistant to dynamic loads - seismic analysis
PublicationThe aim of the article is to present results of seismic analysis results of two real-sized timber frame buildings subjected to seismic excitations. The first model was insulated with mineral wool, the second one with polyurethane foam. Technology and specifications involved in both models construction is based on the previously conducted experimental research on timber frame houses, including wall panels tests, wall numerical models...
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Novel Cast Polyurethanes Obtained by Using Reactive Phosphorus-Containing Polyol: Synthesis, Thermal Analysis and Combustion Behaviors
PublicationPhosphorus-containing polyol applications in polyurethane synthesis can prevent volatilization of flame retardants and their migration on the surface of a material. In this work, novel cast polyurethanes were prepared by a one-step method with the use of different amounts of phosphorus-containing polyol, 4,4′–diphenylmethane diisocyanate and 1,4-butanediol. The chemical structure, thermal, physicochemical and mechanical properties...
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Production activity control in a flexible machining cell considering part measuring condition. W: Computer integrated manufacturing. Advanced design and management. Ed.: B. Skołud, D. Krenczyk. Warszawa: Wydaw. Nauk.-Tech. **2003 s. 494-501, 6 rys. 1 tabl. bibliogr. 9 poz. Sterowanie procesu produkcyjnego w elastycznym gnieździe obróbkowym z uwzg- lędnieniem funkcji kontroli wytwarzanych przedmiotów.
PublicationPrzedstawiono modele struktur organizacyjnych przebiegu procesu organizacyj-nego w rzeczywistym zrobotyzowanym elastycznym gnieździe obróbki (EGO) z udziałem współrzędnościowej maszyny pomiarowej CNC. Badano eksperymentalnie występujące współzależności pomiędzy analizowanymi planami kontroli przed-miotów wytwarzanych i strategiami szeregowania operacji procesu technologi-cznego obróbki, z wykorzystaniem zintegrowanych modeli...
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Experimental examination of an elastomeric polymer
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared elastomeric polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure....
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Experimental study on static and dynamic properties of polymer mass
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure. The aim of the...
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Comparison of elastic and viscoelastic analysis of asphalt pavement at high temperature
PublicationThere are many various rheological models which are used for modeling of asphalt layers in flexible pavement structures. It can be expected that the use of various models may affect different results of mechanical pavement calculations and analysis. The paper presents comparison of the use of Burgers’ and Huet-Sayegh’s viscoelastic models and Hooke’s elastic model to calculate pavement deflections and strains at the bottom of asphalt...
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New-fangled sources of cellulose extraction: comparative study of the effectiveness of Cissus latifolia and Ficus benghalensis cellulose as a filler
PublicationRecycled polymers and biopolymers are receiving a great deal of attention these days. If these two can be combined, it will lead to an environment-friendly green material with a great deal of applications. Here the present work is about incorporating bio-based fillers in a recycled polyurethane matrix. Two unusual and extremely novel sources of cellulose have been proposed. The celluloses obtained from Cissus latifolia and Ficus...
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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...
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Assessment of the impact of bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes)
PublicationThe assessment of the impact of the bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes) Tecoflex® and Tecothane® is presented. The polyurethane samples were incubated with pure cultures of the microorganisms at 30 °C for five months. The changes in the chemical structure of the polymers were evaluated using loss of weight and contact angle...
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The influence of variants of finishing machining on scheduling of shaft components manufacturing
PublicationIn the paper variants of technological processes were presented to the study for piston rods and rams of hydraulic cylinders taking issues into consideration scheduling of course of the production in flexible manufacturing cell. At the carried study an attempt of the estimation of the influence of technological variants on the effectiveness to manufacture the flexible manufacturing system on the basis of preliminary schedules of...
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The POCOBIO Database for Computed Scattering Cross-Sections for Positron Collisions with Biomolecular Systems
PublicationThe design of a database for positron interactions with biomolecular systems is outlined. The database contains only scattering cross sections, which are derived from theory. The data model is defined in a very flexible way, which facilitates the usage of weakly bound clusters of molecules and molecular systems with many tautomeric forms.
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Influence of windsurfing fin stiffness distribution on the lift-drag characteristics
PublicationThis article addresses the problem of determining the hydromechanical loads generated by flexible hydrofoils. The research was done on the example of the composite windsurfing fin for the RS:X monotype class. Despite the assumption of fins identity, everyday practice showed that variations of mechanical properties occur and strongly affect their performance. Therefore, we decided to study the differences between the windsurfing...
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Adapting a General Tool to Monitoring Multi-Agent Systems Through Virtual Host Layer Extenstion
PublicationNagios is a free software for IT infrastructure monitoring. Out-of-the-box it is not suited for monitoring multi-agent systems, because agents may dynamically join and leave the system or change roles. But Nagios' flexible configuration makes extensions possible. This paper presents and verifies Nagios configuration and extensions for monitoring multi-agent systems.
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Experimental and Numerical Study on Pounding of Structures in Series
PublicationPounding between structures in series during earthquakes may cause serious damage in the structural elements. The aim of this paper is to show the results of an experimental and numerical study that is focused on pounding between more than two structures which may be described as “structures in series”. In this study, the shaking table experiments, as well as the numerical analyses, were performed using three tower models including...
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Drivetrain of a Wind Turbine
PublicationIn a most commonly met design of a wind turbine the power is transmitted from the rotor to the generator through the system composed of the main shaft, friction connection, multiplying gearbox and a flexible coupling. The driving system comprises almost a complete set of the machine elements being described during machine design lectures and can serve as an interesting illustration...
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UKŁAD PRZENIESIENIA NAPĘDU TURBINY WIATROWEJ
PublicationIn a most commonly met design of a wind turbine the power is transmitted from the rotor to the generator through the system composed of the main shaft, friction connection, multiplicating gearbox and a flexible coupling. The driving system comprises almost a complete set of the machine elements being described during machine design lectures and can serve as an interesting illustration of the lectures.
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Wideband crossover structure with double ring resonators
PublicationThe structure of a four-port microstrip crossover is presented. The device is composed of two ring resonators, one circular and one built from meander lines, connected by four straight lines. The equivalent circuit model of the crossover is derived. The structure is designed on thin and flexible substrate to allow it to bend. The possibility of applying the device on curved surfaces is tested experimentally.
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Experimental determination of basic mechanical properties of elastomeric polymer
PublicationThere are a lot of different methods of repairing and reinforcing damaged structures, but when it comes to historical buildings and other cultural heritage objects, it is as much about mechanical safety as the aesthetical aspects. Recently, a new and innovative method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been proposed. This new and innovative technique, known as the Flexible...
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Novel single-stage buck-boost inverter with unfolding circuit
PublicationA novel solution of a single-stage buck-boost inverter with unfolding circuit at the output stage is presented. The inverter has a wide range of input voltage regulation, minimum passive components and a very flexible control structure. It can be applied for renewable energy systems where high power density is required. Our simulation results confirmed all theoretical statements
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Piękno i Energia – odnalezione wartości w budowaniu współczesnego miejskiego środowiska zamieszkania
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Styrene epoxidation over heterogeneous manganese(III) complexes
PublicationThe manganes(III) complex functionalised with 2,3-dihydropyridazine has been encapsulated in the supercages of the NaY zeolite using two different procedures, flexible ligand and in situ complex. The parent zeolite and the encapsulated manganese(III) complexes were screened as catalysts for styrene oxidation by using t-BOOH as the oxygen source in acetonitrile. Under the optimized conditions, the catalysts exhibited moderate activity...
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Business Process Modelling and Enterprise Improvement Analysis
PublicationThe main trends in developing an approach and tools for business process modelling are discussed. Business Process Management (BPM) and BPM Notation (BPMN) are presented. Moreover, the possibilities of C2NIWA in a wide range of these tools running on a supercomputer are suggested. Firstly, the company development strategy can be planned . Secondly, quick and flexible changes of its processes can be modelled, analysed and implemented....
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Micro-Raman spectroscopy in the studies of multiphase separated polyurethanes. [online] W: [Proc.] UTECH Europe 2003 . The International Polyurethane Industry Conference and Exhibition. 25/26/27 March 2003, The Hague, Netherlands. London: Crain Communications Ltd. Dostępny w World Wide Web: http://UTECH-2003.com + wydruk.**2003 [s. 123-130 bibliogr. 41 poz.]Mikro-Ramanowska spektroskopia w badaniach poliuretanów wykazujących separację wielofazową.
PublicationPrzedmiotem badań były trzy próbki poliuretanowe o zawartości 30% segmentówsztywnych otrzymanych z politlenku propylenu, diizocyjanianu difenylometanui butanodiolu. Próbki te wykazują morfologię wielofazową, w której można wy-różnić globule i sferolity rozproszone w matrycy polimerowej.Za pomocą spek-troskopii mikro-Ramana przeprowadzono mikroanalizę chemiczną wszystkich ele-mentów morfologicznych. Stwierdzono odmienny skład...