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Szacowanie złożoności czasowej projektu informatycznego
PublicationArtykuł analizuje czasową złożoność projektu informatycznego jako kwalifikowaną prognozę z uwzględnieniem doświadczeń modeli COCOMO. Na wstępie, dyskusji poddano zaproponowaną funkcję prognostyczną. Z kolei wskazano na szereg, także pozatechnicznych, czynników, mających wpływ na powodzenie projektu. Wreszcie pokazano formuły opisujące trójwymiarową integrację systemową w obszarze: osobowym, softwarowym i hardwarowym. W podsumowaniu...
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Szacowanie złożoności czasowej projektu informatycznego
PublicationArtykuł analizuje złożoność projektu informatycznego jako kwalifikowaną prognozę z uwzglednieniem doświadczeń modeli COCOMO. Na wstepie, dyskusji poddano zaproponowaną funkcję prognostyczną. Z kolei wskazano na szereg, także pozatechnicznych, czynników, mających wpływ na powodzenie projektu. Wreszcie pokazano formuły opisujaace trójwymiarową integrację systemową w obrzasze: osobowym, softwarowym i hardwarowym. W podsumowaniu wskazano...
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Port-Based Modelling of Distributed-Lumped Parameter Systems
PublicationThere in the paper is presented an uniform, port-based approach to modelling of both lumped and distributed parameter systems. Port-based model of the distributed system has been defined by application of bond graph methodology and distributed transfer function method (DTFM). The approach proposed combines versatility of port-based modelling and accuracy of distributed transfer function method. The concise representation of lumped-distributed...
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On neutral differential equations and the monotone iterative method
PublicationThe application of the monotone iterative method to neutral differential equations with deviating arguments is considered in this paper. We formulate existence results giving sufficient conditions which guarantee that such problems have solutions. This approach is new and to the Authors' knowledge, this is the first paper when the monotone iterative method is applied to neutral first-order differential equations with deviating...
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Comparison of Polish and Danish Approach to Promotion of Cycling
PublicationThe article describes two different approaches to promotion of cycling from Denmark and Poland. In the former the promotion locally from 2009 to 2015 has been supported financially by the national government and where initiatives partly have been financed by the national level. In Poland, the promotion has been implemented often as a result of bottom up initiatives and financed solely on local level often with the support of EU...
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On well-posedness of the first boundary-value problem within linear isotropic Toupin–Mindlin strain gradient elasticity and constraints for elastic moduli
PublicationWithin the linear Toupin–Mindlin strain gradient elasticity we discuss the well-posedness of the first boundary-value problem, that is, a boundary-value problem with Dirichlet-type boundary conditions on the whole boundary. For an isotropic material we formulate the necessary and sufficient conditions which guarantee existence and uniqueness of a weak solution. These conditions include strong ellipticity written in terms of higher-order...
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Mathematical analysis of a generalised p53-Mdm2 protein gene expression model
PublicationWe propose the generalisation of the p53-Mdm2 protein gene expression model introduced by Monk (2003). We investigate the stability of a unique positive steady state and formulate conditions which guarantee the occurrence of the Hopf bifurcation. We show that oscillatory behaviour can be caused not only by time lag in protein transcription process, but also can be present in the model without time delay. Moreover, we investigate...
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Acceleration waves in the nonlinear micromorphic continuum
PublicationWithin the framework of the nonlinear elastic theory of micromorphic continua we derive the conditions for propagation of acceleration waves. An acceleration wave, also called a wave of weak discontinuity of order two, can be treated as a propagating nonmaterial surface across which the second derivatives of the placement vector and micro-distortion tensor may undergo jump discontinuities. Here we obtain the acoustic tensor for...
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Elektryczne i magnetyczne statyczne podatności multipolowe jednoelektronowego atomu Diraca w stanie podstawowym
PublicationW rozprawie rozważono relatywistyczny atom jednoelektronowy w stanie podstawowym umieszczony w statycznym multipolowym polu elektrycznym i magnetycznym. Wykorzystano rachunek zaburzeń, wraz z rozwinięciem sturmowskim uogólnionej funkcji Greena-Diraca-Coulomba [R. Szmytkowski, JPhys. B 30 (1997) 825; errata 30 (1997) 2747], co umożliwiło wyznaczenie analitycznych wyrażeń dla podatności multipolowych pól dalekich i pól bliskich....
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Applying Generative Modelling Tools to Explore Architectural Forms
PublicationThe digital generative methods open up new areas for exploration of formal and tectonic features, accentuate form’s ability to emerge and perform. They allow for automatic generation of variations of solutions, and digital production of “difficult” components of architectural forms using CNC technology.The paper deals with contemporary architectural explorations of complex , curvilinear surfaces in the context of generative...
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Non-compulsory practical education programme for modernist heritage
PublicationA non-compulsory programme for students of architecture that contains more specialised topics beyond the basic subjects is an important educational tool. The advantages include classes in smaller groups, the possibility of practical exercises in real field conditions and the benefits of meeting professional practitioners. This type of programme is particularly useful for teaching architectural heritage of the 20th Century, its...
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What Potential Entrepreneurs from Generation Y and Z Lack-IEO and the Role of EE
PublicationThis paper addresses the issue of individual entrepreneurship orientation (IEO) and entrepreneurship education (EE), which are both important for modern economic development. Intergenerational differences in these areas were discussed, especially characteristics of Generations Y and Z. The results of research conducted among 757 Polish students showing their IEO are presented. 80% of respondents displayed high levels of proactivity...
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The uses of the pressuremeter test for the design of north transversal tunnel in Grenoble
PublicationWyniki otrzymane z badań presjometrycznych wykorzystano do obliczeń statycznych za pomocą programu Extreme, którym wyznacza się wartość średnią X, odchylenie standardowe, wartość charakterystyczną Xk i rozkład teoretyczny każdego z parametrów. Obliczono wartość charakterystyczną kąta tarcia wewnętrznego dla każdego rodzaju gruntów z prawdopodobieństwem Alfa (równym 5%). Badano rozkłady: normalny, log normalny, wykładniczy, Weybulla,...
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Entrepreneurial education and attitudes among young generations in a gender perspective: the case of Polish educational system
PublicationThis paper is an attempt to analyze the impact of entrepreneurship education on entrepreneurial attitudes and intentions of young people: male and female students of Polish high schools and universities. The author makes an effort to verify the impact of the exposure to the business education and entrepreneurs on the decision to start-up. Special emphasis will be placed on the gender differences when discussing a respective factors’...
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Entrepreneurial Education and Attitude among Young Generations in a Gender perspective: the Case of Polish Education System
PublicationThis article is an attempt to analyze the impact of entrepreneurship education on entrepreneurial attitudes and intentions of young people: male and female students of Polish high schools and universities. The author makes an effort to verify the impact of the exposure to the business education and entrepreneurs on the decision to start-up. Special emphasis will be placed on the gender differences when discussing a respective factors’...
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Multidimensional Scaling Analysis Applied to Music Mood Recognition
PublicationThe paper presents two experiments aimed at categorizing mood associated with music. Two parts of a listening test were designed and carried out with a group of students, most of whom where users of online social music services. The initial experiment was designed to evaluate the extent to which a given label describes the mood of the particular music excerpt. The second subjective test was conducted to collect the similarity data...
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Balance Between Creativity and Methodology in Software Projects
PublicationTaking into account trends of innovation in economy and increasing interest in applying creativity techniques in computer science, this paper focuses on relationship between creativity and methodology in software project. First, it extracts useful knowledge about creativity from creativity research. Then, it makes an attempt to combine creativity issues and dimensions with concepts from software project area. It presents also lessons...
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Specjalność Marketing na Wydziale Zarządzania i Ekonomii - początki i perspektywy
PublicationArtykuł omawia wyniki badań ankietowych przeprowadzonych wśród studentów specjalność Marketing. W konkluzji stwierdzono, że: powołanie specjalności Marketing było decyzją trafną. Program wymaga modyfikacji w kierunku zwiększenia liczby przedmiotów kierunkowych oraz zajęć praktycznych. Wskazane jest kontynuowanie badań w roku przyszłym.
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Politechnika w Gdańsku w latach 1904-1921
PublicationOmówiono uwarunkowania prawne dotyczące organizacji uczelni i jej strukturę. Kolejno przedstawiono nakłady finansowe na budowę obiektów i ich wyposażenie do roku 1904 i w następnych, kiedy to budowano kolejne laboratoria. Podano też informacje dotyczące liczby studentów, absolwentów i promocji doktorskich.
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Re:Brick, czyli budowanie z małych elementów
PublicationArtukuł opisuje problematykę aktywizowania działań łaczacych różne podmioty (studenci architektury i innych kierunków, praktykujący architekci, organizacje społeczne, administracja) mających przyczynić się podniesienia walorów architektonicznych i standardu zamieszkiwania w historycznych dzielnicach Gdańska (Dolne Miasto, Nowy Port, Biskupia Górka, Dolny Wrzeszcz).
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POLAND RULES! - Polska rządzi! Relacja z regat łodzi solarnych Dong Energy Solar Challenge 2014
PublicationW 2014 r. Studenci Wydziału Oceanotechniki i Okrętownictwa Politechniki Gdańskiej, członkowie Koła Naukowego „KORAB” zwyciężyli w regat łodzi zasilanych energią słoneczną Dong Energy Solar Boats Challenge – Holland 2015. W artykule opisano przygotowania do regat, łódź solarną oraz przebieg regat.
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Proces zarządzania relacjami przez szkoły wyższe
PublicationW artykule przedstawiono pojęcie relacji i zarządzania relacjami w kontekście szkół wyższych i studentów jako propozycję działań mających na celu osiąganie celów rynkowych uczelni. Zaprezentowano różne fazy procesu tworzenia relacji oraz przykładowe działania, które powinny być w nich podejmowane.
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OIL-ASSISTED THERMO-MECHANICAL RECLAMATION OF GROUND TIRE RUBBER
PublicationNowadays, it is crucial to seek for the methods of by-products and waste utilization, considering both environmental and economic factors. The example of waste material generated in the massive amounts, which requires the attention is ground tire rubber generated during recycling of post-consumer car tires. It can be applied as a filler into different polymer matrices, but to enhance its effectivity proper modifications should...
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The Impact of Ground Tire Rubber Oxidation with H2O2 and KMnO4 on the Structure and Performance of Flexible Polyurethane/Ground Tire Rubber Composite Foams
PublicationThe use of waste tires is a very critical issue, considering their environmental and economic implications. One of the simplest and the least harmful methods is conversion of tires into ground tire rubber (GTR), which can be introduced into different polymer matrices as a filler. However, these applications often require proper modifications to provide compatibility with the polymer matrix. In this study, we examined the impact...
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THERMOMECHANICAL PERFORMANCE OF FLEXIBLE POLYURETHANE FOAMS AS A FUNCTION OF THE ISOCYANATE INDEX
PublicationPolyurethane foams are very versatile materials applied in different branches of industry. Their popularity is attributed, among others, to the flexibility in engineering their mechanical performance by the adjustment of their formulations. One of the most crucial factors is the isocyanate index, determining the ratio between the free hydroxyl and isocyanate groups present in the polyurethane system. By the change of this ratio,...
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Mechanical Properties, Microstructure and Surface Quality of Polypropylene Green Composites as a Function of Sunflower Husk Waste Filler Particle Size and Content
PublicationAgricultural waste is a still untapped source of materials that can, in case of proper utilization, significantly improve the sustainability of polymers and their composites. In this work, polymer composites based on isotactic polypropylene were produced incorporating ground sunflower husk in the amount of 10 wt% and 20 wt%. The work’s main objective is to evaluate how preliminary fractioning of this agricultural waste filler affects...
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Microwave treatment in waste rubber recycling – recent advances and limitations
PublicationEnvironmentally-friendly microwave heating is increasingly used in polymer chemistry and technology. The selectivity and highly efficiency in the heat transfer present a huge advantage in systems based on recycling, improving their productivity and economic competitiveness. In case of the industrial recycling of waste rubbers, especially end-of-life tires, microwave-induced devulcanization and pyrolysis are nowadays considered...
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Modyfikacja biodegradowalnych poliestrów ialifatycznych i ich mieszanin w obecności inicjatorów nadtlenkowych.
PublicationStreszczenie Czynniki ekologiczne, ekonomiczne oraz większa świadomość społeczeństwa wpływają korzystnie na dynamiczny rozwój biodegradowalnych materiałów, które sukcesywnie zastępują polimery „konwencjonalne”. Na szczególną uwagę zasługują komercyjnie dostępne poliestry alifatyczne takie jak: poli(kwas mlekowy) (PLA), poli(3-hydroksymaślan) (PHB), oraz poli(ε-kaprolakton) (PCL). Jednakże ich wysoka cena oraz problemy technologiczne...
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Injectable poloxamer/graphene oxide hydrogels with well‐controlled mechanical and rheological properties
PublicationAlthough significant progress has been made in the design and application of injectable hydrogels for biomedical applications, concurrent control of rheological and mechanical properties of injectable hydrogels has remained as an open challenge to the researchers. In this work, we introduce and put into practice a photo‐curable poloxamer (also known as Pluronic)/graphene oxide (Plu/GO) injectable hydrogel with well‐controlled rheological...
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Assessment of the devulcanization process of EPDM waste from roofing systems by combined thermomechanical/microwave procedures
PublicationEthylene-propylene-diene rubber (EPDM) is a elastomer widely used in common industrial applications. EPDM can be shaped into sheets and employed as isolating material for roofing systems. In this study, scraps of EPDM from commercial, industrial and residential roofing systems were treated by combined thermo-mechanical and microwave devulcanization processes including peroxide of benzoyl (BPO). The devulcanized EPDM (Dev-EPDM)...
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Recycling of Waste Rubber by the Manufacturing of Foamed Polyurethane-Based Composites—Current State and Perspectives
PublicationWorn car tires are disruptive waste, and the issue of their management is crucial for the natural environment. In many countries, the primary method of end-of-life tires utilization is energy recovery. However, more effective and beneficial for the environment is material recycling. Using them for the production of polymer-rubber composites seems to be an auspicious direction of research. Incorporation of ground tire rubber into...
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THE IMPACT OF GROUND TIRE RUBBER TREATMENT ON THE THERMAL CONDUCTIVITY OF FLEXIBLE POLYURETHANE/GROUND TIRE RUBBER COMPOSITES
PublicationWaste car tires are burdensome waste, and their utilization is crucial for the natural environment. In many countries, the primary method of their recycling is energy recovery, performed by simple combustion. However, material recycling is much more effective and significantly more beneficial for the natural environment. It results in the generation of ground tire rubber, which can be used to produce polymerrubber composites. It...
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DETERMINATION OF THE HYDROXYL NUMBER OF GROUND TIRE RUBBER PARTICLES VIA MODIFIED TEST METHOD FOR ISOCYANATE GROUPS
PublicationNowadays, considering the environmental trends and law regulations associated with the circular economy, it is very important to seek for the methods of by-products and waste utilization. The example of such material, which requires the attention and recycling method is ground tire rubber generated during recycling of post-consumer car tires. It can be introduced into various polymer matrices as a filler, but to enhance its effectivity...
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The influence of feed rate and shear forces on the devulcanization process of ground tire rubber (GTR) conducted in a co-rotating twin screw extruder
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Reinforcing and plasticizing effects of reclaimed rubber on the vulcanization and properties of natural rubber
PublicationThe production of high-added value reclaimed rubber (RR) is of great signifi-cance for the sustainability of rubber industries. To green recycle waste rub-bers and broaden the application of RR, a RR material with potentialreinforcing and plasticizing effects on nature rubber (NR) composites are pre-pared by a thermo-oxidative reclamation process. The reclamation degree ofRR is controlled by adjusting the content of soybean oil....
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Effect of ground tire rubber on structural, mechanical and thermal properties of flexible polyurethane foams
PublicationFlexible polyurethane foams were modified with two kinds of ground tire rubber, untreated and thermo-mechanically reclaimed. A reclamation process was performed in auto-thermal conditions, which reduced the cost of the process and decreased the environmental impact of devulcanization (e.g., emission of gases). The reclamation process was carried out in a continuous manner using a co-rotating twin screw extruder. The foams were...
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Rigid polyurethane foams modified with ground tire rubber - mechanical, morphological and thermal studies
PublicationRigid polyurethane foams, prepared by a single step method, were modified with the two types of ground tire rubber particles, i.e. untreated and thermo-mechanically reclaimed by using a co-rotating twin screw extruder. The foaming process as well as the structure and the physical, mechanical and thermal properties of the resulting foams were investigated. The presence of ground tire rubber decreased the velocity of polymerization....
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Polyurethane/ground tire rubber composite foams based on polyglycerol: processing, mechanical and thermal properties
PublicationDuring the synthesis of rigid polyurethane foams, petrochemical polyol was substituted with polyglycerol, the product of thermo-catalytic polycondensation of waste glycerol, resulting from biodiesel production. Two types of ground tire rubbers, untreated and thermo-mechanically reclaimed, were used to obtain ‘‘green’’ polyurethane-polyglycerol composite foams. Samples were prepared by a single-step method for the ratio of NCO/OH...
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The emissions of monoaromatic hydrocarbons from small polymeric toys placed in chocolate food products
PublicationThe article presents findings on the emissions of selected monoaromatic hydrocarbons from children's toys placed in chocolate food products. The emission test system involved the application of a new type of microscale stationary emission chamber, μ-CTE™ 250. In order to determine the type of the applied polymer in the manufacture of the tested toys, Fourier transform infrared spectroscopy and thermogravimetric analysis coupled...
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Ekologiczne pianki poliuretanowe otrzymane z surowców odnawianych
PublicationPrzedmiotem pracy była charakterystyka ekologicznych, sztywnych pianek poliuretanowych otrzymanych z biopoliolu uzyskanego w wyniku upłynniania biomasy celulozowej frakcją glicerynową. Sztywne pianki otrzymano metodą jednoetapową z układu dwukomponentowego przy stosunku grup NCO do OH wynoszącym 2:1. Udział biopoliolu w stosunku do zawartości komercyjnego poliolu wynosił odpowiednio 25, 50, 75 oraz 100 % mas. Otrzymane układy scharakteryzowano...
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Wpływ bezhalogenowych związków zmniejszających palność na strukturę oraz właściwości mechaniczne i termiczne elastycznych pianek poliuretanowych otrzymanych z poliglicerolu
PublicationElastyczne pianki poliuretanowe zostały przygotowane metodą jednostopniową z układu dwukomponentowego o stosunku grup NCO/OH wynoszącym 0.9:1. Pianki poliuretanowe poddano modyfikacji grafitem ekspandowanym oraz jego mieszaniną z fosforowym, bezhalogenowym związkiem zmniejszającym palność o nazwie handlowej Fyrol PNX. Scharakteryzowano statyczne i dynamiczne właściwości mechaniczne, morfologię, właściwości termiczne oraz palność...
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Morfologia, w³aoeciwooeci mechaniczne i termiczne elastycznych pianek poliuretanowych modyfikowanych glinokrzemianami warstwowymi
PublicationWytwarzane z udzia³em poligliceryny elastyczne pianki poliuretanowe modyfikowano za pomoc¹ montmorylonitu sodowego (bentonitu, MMT), mieszaniny bentonitu i bezhalogenowego fosforoorganicznego zwi¹zku zmniejszaj¹cego palnooeæ (Fyrol PNX) oraz, stanowi¹cego nape³niacz hybrydowy, bentonitu modyfikowanego wykorzystywanym uniepalniaczem. Badano mikrostrukturê, w³aoeciwooeci mechaniczne i termiczne modyfikowanych pianek poliuretanowych....
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Morfologia, właściwości mechaniczne oraz palność spienionych materiałów poliuretanowo-poliglicerynowych modyfikowanych grafitem ekspandowanym
PublicationSpienione kompozyty poliuretanowo-glicerynowe modyfikowane grafitem ekspandowanymotrzymano metodą jednostopniową z układu dwukomponentowego, gdzie jako składnik poliolowyzastosowano odpadową poliglicerynę. Scharakteryzowano morfologię, właściwościmechaniczne oraz klasę palności otrzymanych materiałów. Uzyskane wyniki wskazują, żewprowadzenie poligliceryny do matrycy poliuretanowej umożliwia otrzymanie materiałówcharakteryzujących...
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Wpływ stopnia dewulkanizacji odpadów gumowych na wybrane właściwości modyfikowanego asfaltu drogowego
PublicationW niniejszej publikacji przedstawiono wyniki badań wpływu warunków dewulkanizacji odpadów gumowych na wybrane właściwości asfaltów drogowych, co umożliwia charakterystykę oddziaływań asfalt-dewulkanizat.
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Processing and structure–property relationships of natural rubber/wheat bran biocomposites
PublicationIn this work, wheat bran was used as cellulosic filler in biocomposites based on natural rubber. The impact of wheat bran content [ranging from 10 to 50 parts per hundred rubber (phr)] on processing, structure, dynamic mechanical properties, thermal properties, physico-mechanical properties and morphology of resulting biocomposites was investigated. For better characterization of interfacial interactions between natural rubber...
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Oxygen concentration regulated the efficient liquefaction of vulcanized natural rubber
PublicationOxidative liquefaction represents a promising avenue for the homogeneous and high-value utilization of waste tire rubber. Given that truck tires predominantly comprise natural rubber (NR), this study investigated the efficient liquefaction of vulcanized NR regulated by oxygen concentration. Remarkably, the liquefaction of vulcanized NR was realized with an oxygen concentration of 75 % at 200 °C within 3 min. FTIR spectroscopy showed...
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Impact and stretching standardized tests as useful tools for assessment of viscoelastic behavior for highly rubberized asphalt binder
PublicationAsphalt binder is generally identified as a brittle material at low service temperature or under high-speed load, and the brittleness becomes serious after weathering aging. Improving the toughness of asphalt binder through adding high-content of crumb tire rubber is an efficient method to solve this problem. Devulcanized rubber modified asphalt binder (DRMA) with different contents (15–40%) of devulcanized rubber (DR) were prepared...
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Flame-Retardant Polymer Materials Developed by Reactive Extrusion: Present Status and Future Perspectives
PublicationThe development of flame retardant polymer materials has two roots, one in materials design, and the other in materials processing. Over recent decades, different types and classes of flame retardant polymer materials have been commercialized to meet safety requirements in the construction, automotive, and coatings industries. In the vast majority of cases, the design and fabrication of new materials presenting low fire hazards...
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Structural and Thermo-Mechanical Properties of Poly(ε-caprolactone) Modified by Various Peroxide Initiators
PublicationThe modification of poly(ε-caprolactone) (PCL) was successfully conducted during reactive processing in the presence of dicumyl peroxide (DCP) or di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB). The peroxide initiators were applied in the various amounts of 0.5 or 1.0 pbw (part by weight) into the PCL matrix. The effects of the initiator type and its concentration on the structure and mechanical and thermal properties of PCL were...
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Enhanced aging resistance of poly(ε-caprolactone)/brewers’ spent grain composites
PublicationThe presented paper investigated the influence of brewers’ spent grain (BSG) extrusion pa-rameters on the photo-oxidative resistance of poly(ε-caprolactone)-based wood polymer composites. Filler samples characterized by the higher melanoidin content were more efficient in hindering of poly-mer degradation, inhibiting the decomposition of the polymer amorphous phase. As aresult, deteriora-tion of mechanical performance was limited,...