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Search results for: ramsey number
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The number of active enterprises in Poland in 1997-2014
Open Research DataAfter Poland joined the group of countries associated in the European Union and through participation in numerous economic and political organizations (including the World Trade Organization, OECD), as well as the commencement of trade exchange with virtually all countries of the world, Polish entrepreneurs and managers struggle with completely problems...
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Number of seasonal work permits issued in 2018
Open Research DataIn 2018, a total of 121,436 seasonal work permits were issued, the vast majority of which were granted to Ukrainian citizens. The following dataset shows the countries from which citizens have been issued the most permits.
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Average number of employees of BPO SSC centers
Open Research DataAlthough most BSS centers are located in Warsaw, the capital of Poland ranks only 4th in terms of the average number of employees. In terms of the average number of employees, Kraków (321) is the leader, followed by Wrocław (281) and Łódź (273).
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Beta-galactosidase activity of Meiothermus ruber cells
PublicationFreeze-dried cells of Meiothermus ruber catalyses cleavage of o-nitrophenyl-b-D-galactopiranoside (oNPb-gal) and conversion of lactose into glucose and galactose. The permeabilization with 2%toluene,20%ethanol and 20%acetone increased enzymatic activity from 74.87 U/g of lyophilized cells up to 129.44,114.38 and 90.19 U/g,respectively. Ethanol was an effective permeabilizing agent and its efficiency was dependent on the concentration,...
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3D Scanning of Semitransparent Amber with and without Inclusions
PublicationThis paper is concerned with making 3D scans of semitransparent ambers with and without inclusions. The paper presents results of using a variety of devices applied for this purpose. Equipment used in the experiments includes a 3D laser scanner, a structured light scanner, a stereo camera, a camera array and a tomograph. The main object used in the experiment was an amber with a fossil of a lizard. The paper shows possibilities...
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Succinite, Baltic Amber: A Chemical Masterpiece of Nature
PublicationSuccinite, Baltic amber, is one of the most appreciated fossil resins. Its beauty has fascinated people since prehistoric times. It is a substance, and also gemstone, whose uniqueness is due to its compelling, though still not fully understood, physicochemical nature. In this article, some facts about the physical and chemical properties of succinite in order to find an answer for questions about the unique properties of this resin,...
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Alkali-activated slag (AAS) and OPC-based composites containing crumb rubber aggregate: Physico-mechanical properties, durability and oxidation of rubber upon NaOH treatment
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A survey on known values and bounds on the Shannon capacity
PublicationIn this survey we present exact values and bounds on the Shannon capacity for different classes of graphs, for example for regular graphs and Kneser graphs. Additionally, we show a relation between Ramsey numbers and Shannon capacity.
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Ekspertyza numer 45/017/II/2016 na temat możliwości prostowania palnikiem stali 316L
PublicationWspółczesne konstrukcje okrętowe często wymagają zastosowania więcej niż jednego rodzaju stali. W przypadku budowy statków rybackich posiadających ładownię RSW, zdarzają się przypadki łączenia stali okrętowej (czarnej) ze stalami austenitycznymi (np. 316L). Konstrukcja wykonana ze stali austenitycznej jest tak samo podatna na odkształcenia spawalnicze, jak konstrukcja ze stali czarnej, w związku z czym należy ją prostować. Ekspertyza...
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Wrażliwość sił wewnętrznych i przemieszczeń w ramie płaskiej z prętów cienkościennych na zmiany parametrów stężeń poprzecznych
PublicationPodano sposób wyznaczania linii wpływu wariacji dowolnego przemieszczenia lub siły wewnętrznej ramy z prętów cienkościennych ze względu na zmiany sztywności stężeń poprzecznych. Porównano dwa modele ramy: klasyczny bez uwzględniania skręcania skrępowanego i z uwzględnieniem tych efektów.
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Compatibility and rheological characterization of asphalt modified with recycled rubber-plastic blends
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Modification of Ground Tire Rubber—Promising Approach for Development of Green Composites
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Studia Rossica Gedanensia 2021, t. 8 (redakcja naukowa numeru)
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Studia Rossica Gedanensia 2022, t. 9 (redakcja naukowa numeru)
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Optimal Shape Refurbishment of Distorted Dome Structure with Safeguarding of Member Stress
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Economic growth, structural change and quality upgrading in New Member States
PublicationThe purpose of this research is to present the recent developments concerning structural change and productivity growth in New Member States and the role played in such process by country specific factors. We focus on ten countries (NMS-10) which joined the EU in 2004 and analyze productivity dynamics of their labor structures between the years 1995 and 2005 in a comparative setting versus EU-15 economies. NMS-10 have gone through...
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Studia Rossica Gedanensia 2023, t. 10 (redakcja naukowa numeru)
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Assessment of the effectiveness of physiotherapy after surgical treatment of the cervical or lumbar spine
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Compatibilization of polymeric composition filled with ground tire rubber – short review
PublicationWaste rubber is recognized as valuable materials resource and searching for new recycling methods is the main activity of many research institutions and companies. At the turn of the last years only few scientific papers about foamed polymer compositions filled with ground tire rubber were published. In paper review about progress in compatibilization and foaming of polymeric compositions filled with ground tire rubber.
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Effect of starch fillers on the dynamic mechanical properties of rubber biocomposite materials
PublicationIn the paper the results of dynamic mechanical study of the biocomposites containing one of two types of (potato or corn) strach used as fillers in different amount were discussed. The composites were obtained from rubbery mixture containing natural rubber (NR) as a main component. Thermomechanical analyses (by DMA) showed that the used quantity of strach fillers only slightly influence on the glass transition temperature of vulcanizates.
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Novel Approaches of Using of Spirulina Platensis in Natural Rubber Based Composites
PublicationThe aim of this work was to investigate the influence of Spirulina (Spirulina platensis) as a natural filler on the curing characterization, morphology and mechanical, thermomechanical and thermal properties of natural rubber (NR) based composites. Spirulina was introduced into NR mixture in amount of 0 phr, 10 phr and 30 phr. The vulcanization process was carried out at the determined process condition by using hydraulic press...
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Modification of Ground Tire Rubber—Promising Approach for Development of Green Composites
PublicationGround tire rubber (GTR) was mechano-chemically modified using a road bitumen 100/150 and two types of organic peroxides: di-(2-tert-butyl-peroxyisopropyl)-benzene (BIB) and dicumyl peroxide (DCP). The impact of used additives on reactive sintering efficiency and physico-mechanical properties of modified GTR was investigated using oscillating disc rheometer measurements, followed by tensile tests and swelling behavior studies....
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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 dynamic study on a timber-frame house using shaking table
PublicationThe aim of this paper is to show the results of the shaking table experimental study concerning the behaviour of the model of the timber-frame house under earthquake excitation and impact loading. In order to determine the basic dynamic properties of the undamaged structure, the free vibration and the sweep-sine tests were first conducted. Then, the model was excited using the time history record of the El Centro earthquake of...
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Characteristic of elastomers from the rubber mixtures (NR) containing devulcanizate compounds
PublicationW pracy omówiono wyniki badań elastomerów otrzymanych w procesie wulkanizacji mieszanek kauczukowych napełnionych kredą i dodatkowo zawierających różne udziały dewulkanizatu. Dewulkanizaty natomiast otrzymano z pyłu gumowego metodą termomechaniczną. Otrzymane elastomery poddano badaniom w warunkach statycznych i przeprowadzono je na maszynie wytrzymałościowej. Określono wpływ czasu wulkanizacji, ilości napełniacza mineralnego oraz...
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Thin-walled cross section shape influence on steel member resistance.
PublicationThis work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into...
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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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Electromagnetic interference frequencies prediction model of flyback converter for snubber design
PublicationSnubber design for flyback converters usually requires experimental prototype measurements or simulation based on accurate and complex models. In this study simplified circuit modelling of a flyback converter has been described to dimension snubbers in early stage of design process. Simulation based prediction of the transistor and diode ringing frequencies has been validated by measurements in a prototype setup. In that way obtained...
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Nonlinear viscoelasticity in Three Dimensional filler reinforced rubber composites and nanocomposites
PublicationThis chapter describes the influence of three-dimensional nanofillers used in elastomers on the nonlinear viscoelastic properties. In particular, this part focuses and investigates the most important three-dimensional nanoparticles, which are used to produce rubber nanocomposites. The rheological and the dynamic mechanical properties of elastomeric polymers, reinforced with spherical nanoparticles, like POSS, titanium dioxide and...
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PRE-FAILURE CONDITION AND THE METHOD OF REPAIRING GLUED TIMBER ROOF BEARS
PublicationDesign documentation of glued-laminated timber roof girders is in many cases very general, does not contain details and design solutions, and the contractors do not have experience in the implementation of this type of structure. Design and execution errors, including those related to glued laminated timber roof girders, not only affect the safety and durability of the structure of the facility in which they were built in, but...
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Green Approaches in Rubber Recycling Technologies: Present Status and Future Perspective
PublicationAs a consequence of massive production and consumption of rubbers, rubber blends, and rubber composites for myriad applications, elastomeric products have enormously accumulated and become an environmental threat. The disposal and burning of rubber wastes have been banned because of environmental and economic reasons. By contrast, a great deal of attention has been directed toward strategies enabling recycling and reuse of rubbers....
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Assessment of the Feasibility of Energy Transformation Processes in European Union Member States
PublicationThe energy transition is now treated in most countries as a necessary condition for their long-term development. The process of energy transformation assumes the simultaneous implementation of the Sustainable Development Goals, which are a major challenge for modern economies and introduce significant restrictions in their functioning. Our study aims to group EU member states according to their ability to achieve energy transition...
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Recycling of Waste Rubber by Thermo-Mechanical Treatment in a Twin-Screw Extruder
PublicationRecycling of waste tires is a significant issue considering both environmental and economic aspects. One of the leading recycling routes is the shredding of tires resulting in the generation of ground tire rubber. This material can be easily introduced into various polymer matrices as a filler, reducing the use of conventionally applied petroleum-based materials. In such cases, it is essential to ensure sufficient interfacial compatibility,...
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Comprehensive analysis of low-temperature methods for reclaiming of ground tire rubber
PublicationManagement of waste tires has become an important topic for decades. The lack of an effective method to manage the materials as mentioned above leads to illegal landfills. This problematic waste can be divided into two main categories depending on the physical condition of the waste: (i) partially used tires; (ii) end-of-life tires. While the first group can be reused or retreaded, the second group requires special measures to...
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NUMERICAL ANALYSIS OF SPECIES DIFFUSION AND METHANOL DECOMPOSITION IN THERMOCATALYTIC REACTOR BASED ON THE INTERMETALLIC PHASE OF Ni3Al FOR LOW REYNOLDS NUMBERS
PublicationNumerical modelling of hydrogen production by means of methanol decomposition in a thermocatalytic reactor using corrugated foil made of the Ni3Al intermetallic phase is shown in the paper. Experimental results of the flow analysis of mixtures containing helium and methanol in a thermocatalytic reactor with microchannels were used for the initial calibration of the CFD calculations (calculations based on the Computational Fluid...
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Jerzy Kowalski dr hab. inż.
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Mid-infrared spectroscopy for characterization of Baltic amber (succinite)
PublicationNatural Baltic amber (succinite) is the most appreciated fossil resin of the rich cultural traditions dating back to prehistoric times. Its unequivocal identification is extremely important in many branches of science and trades including archeology, paleontology, chemistry and finally mineralogical and gemological societies. Current methods of modification of natural succinite are more and more sophisticated making the identification...
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Meiothermus ruber cells as β-galactosidase activity biocatalyst
PublicationThe current study allowed to establish the possibility of using whole cells of thermophilic bacteria Meiothermus ruber as a biocatalyst with β-galactosidase activity. β-galactosidases are used for hydrolysis of lactose as well as for oligosaccharides synthesis. The advantages of using whole bacterial cells catalysis is not only elimination of tedious, expensive protein isolation and/or purification but also stabilization of enzymes...
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The number of students in public and private universities in 1990-2011
Open Research DataFrom the 2005/2006 academic year - when the number of students reached a record value of 1,953.8 thousand - the number of students is systematically decreasing. Within 5 years, this number decreased by 5.8%, and over the last year, the decrease amounted to 3.1%. These changes are related to the constantly decreasing number of people aged 19-24. Despite...
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The number of enterprises in Poland and selected EU countries in 2012
Open Research DataIn 2012, Poland was sixth in the ranking of the number of enterprises in selected European Union countries. In total, 22 million companies conduct business in the countries of the Community. However, when analyzing these values in relative numbers (calculated as the number of enterprises per 1000 inhabitants), Poland ranks only 22nd among the Member...
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The number of enterprises in Poland and EU countries (in thousands) in 2019
Open Research DataEnterprises from the SME sector constitute the majority of companies in Poland and in the European Union countries. However, the structure of domestic enterprises in terms of size and industry differs from the EU average. The following dataset contains the number of enterprises in Poland and EU countries (in thousands) in 2019.
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The number of enterprises in Poland and EU countries (in thousands) in 2019
Open Research DataEnterprises from the SME sector constitute the majority of companies in Poland and in the European Union countries. However, the structure of domestic enterprises in terms of size and industry differs from the EU average. Taking into account the nature of the business in Poland, more companies operate in trade, and lower in services. However, it should...
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Analiza konstrukcji ramy nośnej wyczynowego roweru wodnego Rektor na przykładzie wybranego węzła
PublicationW pracy poruszono problem zmniejszenia masy wyczynowego roweru wodnego Rektor bez utraty jego wytrzymałości. W tym celu przeprowadzone zostały wieloetapowe obliczenia wybra- nego węzła konstrukcyjnego. Ponadto omówiono technologię wykonania rur kompozytowych. Podczas analizy sprawdzono trzy przypadki różniące się materiałem, z którego wykonano ramę, odpowiednio: z aluminium, laminatu zbrojonego włóknem szklanym oraz laminatu zbrojonego...
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Czy Krajowe Ramy Kwalifikacji są elementem podnoszącym jakość kształcenia na studiach wyższych?
PublicationW artykule przedstawiono znaczenie Krajowych Ram Kształcenia (KRK) w aspekcie Europejskich Ram Kształcenia. Zanalizowano wpływ KRK na jakość kształcenia na studiach wyższych. Szczególną uwagę zwrócono na zalety programu wdrażania KRK na poszczególnych uczelniach z punktu widzenia działalności administracji oraz na niebezpieczeństwa dla jakości kształcenia wynikające ze zmniejszeniem elastyczności modyfikacji programów studiów,...
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Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...
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Emphysema affects the number and appearance of solitary pulmonary nodules identified in chest low-dose computed tomography: a study on high risk lung cancer screenees recruited in Silesian District
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Life Cycle Cost Assessment and the Optimum Design of Timber Roofs for Sustainable Construction
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Autorska implementacja systemu wymiany numera-cji telefonicznej pomiędzy operatorami voip
PublicationW pracy przedstawiono autorską implementację systemu wymiany numeracji. System został stworzony w technologii Java, wykorzystując otwarte rozwiązania bazodanowe MySQL oraz PostgreSQL. System został przetestowany dla kilku klientów/operatorów wykorzystujących pule z ponad milionem numerów telefonicznych. W pracy wykazano spełnienie podstawowych wymagań narzucanych na system, w szczególności czas odpowiedzi systemu informacji o numerze...
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Kompozyty poliuretanowo-gumowe wulkanizowane siarką = Polyurethane-rubber composites vulcanization of sulphur
PublicationW artykule przedsawiono wyniki badań statycznych i dynamicznych właściwości mechanicznych oraz analizę mikroskopową nowych kompozytowych materiałów poliuretanowo-gumowych wulkanizowanych siarką otrzymanych z kauczuków uretanowych wulkanizowanych siarką i recyklatu gumowego w postaci granulatu o wielkości ziarna do 1 mm uzyskanego z poużytkowych opon samochodowych. Osnowy poluretanowe napełniano recyklatem w ilościach od 10 do 80%...
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Influence of manganese(II) silanethiolate with 1,10-phenathroline on properties of natural rubber vulcanizates
PublicationW komunikacie zaprezentowano wstępne wyniki badań dotyczących wpływu kompleksu [Mn{SSi(OBu-t)3}2(phen)] na właściwości wulkanizatów gumowych z kauczuku naturalnego. Przeprowadzone badania sugerują, że chociaż związek ten nie działa bezpośrednio jako przyspieszacz, to aktywuje wulkanizację przy użyciu tiuramu.