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Search results for: elephant grass
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Performance properties of rigid polyurethane-polyisocyanurate/brewers’ spent grain foamed composites as function of isocyanate index
PublicationIn the presented work, rigid polyurethane-polyisocyanurate (PUR-PIR) foams filled with brewers’ spent grain (BSG) were prepared. The influence of the isocyanate index (II) on its performance was investigated. Foams obtained with higher isocyanate index required a higher amount of hydrofluorocarbon physical blowing agent to provide the same apparent density of material. An increase of isocyanate index resulted in a slight decrease...
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Modelling Wetland Growing Season Rainfall Interception Losses Based on Maximum Canopy Storage Measurements
PublicationThis study estimates rainfall interception losses from natural wetland ecosystems based on maximum canopy storage measurements. Rainfall interception losses play an important role in water balance, which is crucial in wetlands, and has not yet been thoroughly studied in relation to this type of ecosystem. Maximum canopy storage was measured using the weight method. Based on these measurements, daily values of interception losses...
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US not bright but right method of thyroid volume estimation even in large and substernal extended goitres. Comparison of US and three methods of CT thyroid evaluation - prospective study.ON LINE
PublicationBackground Ultrasound is nowadays a method of choice for thyroid volume assessment. However, its disadvantage is some inaccuracy, which is said to be higher in huge, especially substernally extended goitres. Aims The aim of the study was to compare the US and CT thyroid volumetric measurements: multi-observers (CT MO) and one-observer (CT OO) to CT planimetry results (CT Pl) in patients with large goitres. Materials & Methods The...
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Nontoxic Goiter (NTG) and Radioiodine: What Do Patients Think About It? Quality of Life in Patients with NTG Before and After 131-I Therapy
PublicationObjective Despite numerous publications regarding nontoxic goiter (NTG) treatment and an increasing interest in patients’ quality of life, few studies present the outcome of 131-I treatment from the patients’ perspective. Our study’s main aim was to verify whether there is any improvement in life quality following 131-I treatment. Materials and methods Thirty-five patients with NTG qualified to participate in the study. All patients...
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Synthesis and thermal studies of flexible polyurethane nanocomposite foams obtained using nanoclay modified with flame retardant compound
PublicationThis work presents thermal studies of nanocomposites based on the flexible polyurethane (PU) matrix and filled using montmorillonite organically modified with organophosphorus flame retardant compound. Flexible PU nanocomposite foams were prepared in the reaction carried out between reactive alcoholic hydroxyl and isocyanate groups with the ratio of NCO to OH groups equal to 1.05. The amount of an organoclay ranging from 3 to 9...
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Contact with coupled adhesion and friction: Computational framework, applications, and new insights
PublicationContact involving soft materials often combines dry adhesion, sliding friction, and large deformations. At the local level, these three aspects are rarely captured simultaneously, but included in the theoretical models by Mergel et al., (2019). We here develop a corresponding finite element framework that captures 3D finite-strain contact of two deformable bodies. This framework is suitable to investigate sliding friction even...
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Evaluating the influence of radiative heat flux on convective heat transfer from a vertical plate in air using an improved heating plate
PublicationThis article examines the influence of radiative heat flux on the accuracy of the results of free convective heat transfer in air. In order to carry out these tests, based on the experience gained during the operation of a plate heated on one side, compensated by a reverse heat loss flux counter-heater, a unique double-sided heating sandwich plate was designed and built, consisting of three thin epoxy resin plates reinforced with...
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New insights on lithium storage in silicon oxycarbide/carbon composites: Impact of microstructure on electrochemical properties
PublicationIn this work, we study the impact of the preceramic precursor vinyltriethoxysilane (VTES) on the electrochemical performance of silicon oxycarbide (SiOC) glass/graphite composites. We apply an innovative approach based on high-power ultrasounds in order to obtain highly homogenous composites with a uniform distribution of small graphitic flakes. This procedure enhances gelation and drying of VTES-based preceramic polymer/graphite...
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Copolymerization of Styrene and Pentadecylphenylmethacrylate (PDPMA): Synthesis, Characterization, Thermomechanical and Adhesion Properties
PublicationThe copolymerization of styrene (St) with a bioderived monomer, pentadecylphenylmethacrylate (PDPMA), via atom transfer radical polymerization (ATRP) was studied in this work.The copolymerization reactivity ratio was calculated using the composition data obtained from1HNMR spectroscopy, applying Kelen-Tudos and Finemann-Ross methods. The reactivity ratio of styrene (r1=0.93) and PDPMA (r2=0.05) suggested random copolymerization...
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The new silica-based coated SPME fiber as universal support for the confinement of ionic liquid as an extraction medium
PublicationThe new silica-based SPME fiber coating is reported for the first time as universal support purposed to confinement of ionic liquid as an extraction medium. Fiber coating was prepared by the sol-gel process, using potassium silicate (K2SiO3) as a precursor and dimethylformamide (DMF) as a pore-forming medium. The concept of synthesis assumes obtaining a solid porous material on the surface of the glass rod and, being characterized...
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Styrene-Butadiene Rubber/Modified Ground Tire Rubber Blends Co-Vulcanization: Effect of Accelerator Type
PublicationGround tire rubber was thermo-mechanically modified with using a co-rotating twin screw extruder. Modification of GTR was conducted in autothermal conditions. Styrene-butadiene rubber and modified ground tire rubber blends were prepared via two-roll milling. Obtained compounds were cured with conventional system (sulfur/vulcanization accelerator ratio was 2:1). During this research three commonly vulcanization accelerators (MBT,...
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Structure analysis and thermal degradation characteristics of bio-based poly(propylene succinate)s obtained by using different catalyst amounts
PublicationLinear bio-based polyester polyols were prepared with the use of succinic acid and 1.3-propanediol (both with natural origin). As a catalyst was used tetraisopropyl orthotitanate (TPT). In order to determine the effect of various catalyst content on the thermal degradation characteristics, three different TPT amounts, as a 1.3-propanediol equivalent, were used, namely 0.1 mass% (PPS-0.1), 0.2 mass% (PPS-0.2) and 0.25 mass% (PPS-0.25)....
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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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On the Correlation of Lignocellulosic Filler Composition with the Performance Properties of Poly(ε-Caprolactone) Based Biocomposites
PublicationIn this work, three types of agricultural waste: olive stones (OS), date seed (DS) and wheat bran (WB) were applied as potential lignocellulosic fillers in poly(ε-caprolactone) (PCL) based biocomposites. Differences in composites’ performance were related to the higher content of proteins, noted for WB comparing to other fillers applied, which enhanced plasticization of PCL matrix. The mechanical properties of biocomposites were...
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GROWTH AND STRUCTURAL CHANGES IN TRANSITION COUNTRIES: THE CHICKEN OR THE EGG?
PublicationThe objective of this study is to test empirically the relationship between structural changes (changes in gross value added and employment) and economic growth. We used a panel Granger-causality analysis based on annual data for eight transition countries, covering the period 1995–2011. The main finding is that the causality relations analysed are heterogeneous processes and are identified more often...
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New matrix-free reference material for ethene in the form of optical fibres
PublicationReference materials are indispensable in the qualitycontrol and quality assurance of analytical measurements. Onenovel approach to the generation of standard gaseous mixturesof toxic, reactive, volatile, labile, and malodorous substancesinvolves thermal decomposition or rearrangement, under definedtemperature conditions, of compounds immobilized, bychemical bonding, on the surface of an appropriate carrier torelease specific amounts...
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CFD COUPLING OF VOF MODEL WITH ARRHENIUS EQUATION FOR ANALYSIS OF LASER-INDUCED THERMAL DEACTIVATION OF E. COLI
PublicationUnderstanding bacterial deactivation at the micro-scale, particularly with E. coli, is crucial for advancing microbiology and has promising applications in biomedical research. In this research contribution, we investigate the thermal inactivation of E. coli bacteria using gold nanoparticles irradiated by a green 1-W laser within a microfluidic chamber. The microfluidic device comprises a fluidic chamber filled with a thin film...
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Design and numerical testing of 5-box gfrp shell footbridge
PublicationThe paper formulates new design conditions for composite footbridges, taking into account the material and structural specificity of these objects, i.e. the strength condition, the serviceability condition and the frequency condition. A GFRP composite footbridge labelled with CFB2 code has been designed, with the original superstructure in the form of an opened-closed 5-box girder. The foot and cycle track bridge is simply supported,...
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Load capacity and serviceability conditions for footbridges made of fibre-reinforced polymer laminates = Warunki nośności i użytkowalności w odniesieniu do kładek z laminatów polimerowych
PublicationThe contribution is focused on derivation of the Ultimate Limit State (ULS) and Serviceability Limit State (SLS) design criteria for footbridges built of fibre-reinforced polymer matrix (FRP) laminates. The ULS design criterion is based on the design guidelines for above-ground, pressure, FRP composite tanks and the Tsai-Wu failure criterion, which is used to predict the onset of FRP laminates damage. The SLS criterion is based...
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Recent advances in traffic optimisation: systematic literature review of modern models, methods and algorithms
PublicationOver the past few decades, the increasing number of vehicles and imperfect road traffic management have been sources of congestion in cities and reasons for deteriorating health of its inhabitants. With the help of computer simulations, transport engineers optimise and improve the capacity of city streets. However, with an enormous number of possible simulation types, it is difficult to grasp valuable, innovative solutions which...
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The vibration-based assessment of the influence of elevated temperature on the condition of concrete beams with pultruded GFRP reinforcement
PublicationConcrete beams reinforced with glass fiber reinforced polymer (GFRP) bars subjected to elevated temperature have been experimentally studied. The influence of high temperatures on GFRP-reinforced concrete beams condition has been check both, destructively and nondestructively. The nondestructive tests foresaw vibration-based tests to obtain the natural frequency values after exposure to varying temperatures. The vibration-based...
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Synthesis and characterization of novel renewable polyesters based on 2,5-furandicarboxylic acid and 2,3-butanediol
PublicationNovel 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...
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Cure Index demonstrates curing of epoxy composites containing silica nanoparticles of variable morphology and porosity
PublicationAn image was taken by Cure Index on curability of epoxy with silica nanoparticles having variable morphology and porosity. Three kinds of silica nanoparticles with non-porous curved-rod, non-porous spherical, and mesoporous spherical microstructures were synthesized and characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy (SEM) and Brunauer–Emmett–Teller analyses. Epoxy nanocomposites containing...
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Multiparameter sensitivity analysis of a GFRP composite footbridge of a sandwich structure and U-shaped cross-section
PublicationThe paper deals with multiparameter sensitivity analysis of a composite footbridge. A shell‐like structure is 14.5 m long shows U‐shaped cross‐section and inner service dimensions 1.3 × 2.5 m. Glass fiber reinforced polymer GFRP laminate constitutes faces of a sandwich structure while PET foam received from recycled bottle builts a core. The structure was divided into 285 independent areas where the thickness of laminates and stiffness...
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Ion conduction in beryllium-alumino-silicate glasses doped with sodium or sodium and lithium ions
PublicationElectrical properties of beryllium-alumino-silicate glasses containing sodium ions or sodium and lithium ions were studied with impedance spectroscopy technique over a frequency range from 10 mHz to 1 MHz and at temperature range from 213 to 473 K. The frequency- and temperature-dependent conductivity spectra of individual single alkali glasses were superimposed by means of the Summerfield scaling. Mixed-alkali glasses do not overlap...
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Typology of low developed non-metropolitan sub-regions in the European Union
PublicationThis paper shows a typology of 319 NUTS-3 sub-regions in the European Union. The selected sub-regions are non-metropolitan sub-regions, whose gross domestic product per capita in 2011 was below 75% of the EU average. The objective of this typology was to recognize diversity in the examined sub-regions as a starting point for the selection of areas for future comparative research. The typology takes into account 24 variables related...
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Experimental and comparative study on the two-phase pressure drop of air-water mixture in U-bend and straight pipe annuli
PublicationIn this paper, the experimental and theoretical analysis of pressure drop in singlephase and two phase-flow were presented for straight and U-bend smooth tube annulus and tube annulus with wire coil insert. Experiments for various boundary conditions were performed. In case of U-tube and straight tube with and without turbulator, tests were made for the water-water and air-water systems. The study covered a wide measuring range,...
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Detection of Delamination in Laminate Wind Turbine Blades Using One-Dimensional Wavelet Analysis of Modal Responses
PublicationThis paper demonstrates the effectiveness of a nondestructive diagnostic technique used to determine the location and size of delamination in laminated coatings of wind turbine blades. This is realized based on results of numerical and experimental investigations obtained by the use of the finite element method (FEM) and laser scanning vibrometry (LSV). The proposed method is based on the one-dimensional continuous wavelet transform...
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Deposition and characterization of organic polymer thin films using a dielectric barrier discharge with different C2Hm/N2 (m = 2, 4, 6) gas mixtures
PublicationOrganic polymer thin films have been deposited on Si(100) and aluminum coated glass substrates by a dielectric barrier discharge (DBD) operated at medium pressure using different C2Hm/N2 (m = 2, 4, 6) gas mixtures. The deposited films were characterized by various spectroscopic techniques. Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS) revealed the chemical functional groups present in the films. The surface...
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Curing characteristics, mechanical and thermal properties of reclaimed ground tire rubber cured with various vulcanizing systems
PublicationGround tire rubber was thermo-mechanical reclaimed at 120 °C using a co-rotating twin screw extruder. The effect of vulcanizing system type on curing characteristics, static mechanical properties (tensile strength, elongation-at-break, hardness and resilience), dynamic mechanical properties and thermal properties of reclaimed ground tire rubber was investigated. Reclaimed rubber was cured using different types of vulcanization...
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Assessment of Citizens’ Actions against Light Pollution with Guidelines for Future Initiatives
PublicationDue to the wide reach of media reports about scientific research and technological tools such as the world wide web (WWW), the Internet, and web browsers, citizens today have access to factual information about the negative impact of artificial light at night (ALAN) on their dark skies, and their health and well-being. This means they can now make educated decisions and take the necessary steps to help protect themselves and their...
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On the origin of surfaces-dependent growth of benzoic acid crystal inferred through the droplet evaporation method
PublicationCrystal growth behavior of benzoic acid crystals on different surfaces was examined. The performed experiments documented the existence of very strong influence introduced by polar surfaces as glass, gelatin, and polyvinyl alcohol (PVA) on the growth of benzoic acid crystals. These surfaces impose strong orientation effect resulting in a dramatic reduction of number of faces seen with x-ray powder diffractions (XPRD). However,...
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Utilization of oriented crystal growth for screening of aromatic carboxylic acids cocrystallization with urea
PublicationThe possibility of molecular complex formation in the solid state of urea with benzoic acid analogues was measured directly on the crystallite films deposited on the glass surface using powder X-ray diffractometry (PXRD). Obtained solid mixtures were also analyzed using Fourier transform infrared spectroscopy (FTIR). The simple droplet evaporation method was found to be efficient, robust, fast and cost-preserving approach for first...
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On the origin of surfaces-dependent growth of benzoic acid crystal inferred through the droplet evaporation method
PublicationCrystal growth behavior of benzoic acid crystals on different surfaces was examined. The performed experiments documented the existence of very strong influence introduced by polar surfaces as glass, gelatin, and polyvinyl alcohol (PVA) on the growth of benzoic acid crystals. These surfaces impose strong orientation effect resulting in a dramatic reduction of number of faces seen with x-ray powder diffractions (XPRD). However,...
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On the origin of surfaces-dependent growth of benzoic acid crystal inferred through the droplet evaporation method
PublicationCrystal growth behavior of benzoic acid crystals on different surfaces was examined. The performed experiments documented the existence of very strong influence introduced by polar surfaces as glass, gelatin, and polyvinyl alcohol (PVA) on the growth of benzoic acid crystals. These surfaces impose strong orientation effect resulting in a dramatic reduction of number of faces seen with x-ray powder diffractions (XPRD). However,...
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Eksperyment: Ekslibris
PublicationEksperyment: Ekslibris Wystawa online 12 eksperymentalnych ekslibrisów inspirowanych wybranymi książkami Güntera Grassa, stworzonych specjalnie dla Gdańskiej Galerii Miejskiej przez zaproszonych do projektu artystów. Przy okazji cotygodniowej inauguracji poszczególnych ekslibrisów, będziemy przybliżać Wam sylwetki każdego z artystów, a także przypominać ważne dla nich projekty, w których wzięli udział. Produktem finalnym całego...
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Application of Artificial Neural Networks to Predict Insulation Properties of Lightweight Concrete
PublicationPredicting the properties of concrete before its design and application process allows for refining and optimizing its composition. However, the properties of lightweight concrete are much harder to predict than those of normal weight concrete, especially if the forecast concerns the insulating properties of concrete with artificial lightweight aggregate (LWA). It is possible to use porous aggregates and precisely modify the composition...
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Oxygen vacancy-enriched V2O5·nH2O nanofibers ink for universal substrates-tolerant and multi means-integratable NH3 sensing
PublicationUniversal substrates-tolerant and multi means-integratable ammonia (NH3) sensing is highly desired in future Internet of Things in environmental monitoring, food security and early diagnosis of human diseases, however, is still less than satisfactory. Here, an oxygen vacancy-governed NH3 sensing has been developed with V2O5·nH2O nanofibers (NFs) ink, via combined thermal decomposition of ammonium metavanadate and dilution. As-obtained...
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Digital Gaps and Economic Inequalities in MENA Countries: An Empirical Investigation
PublicationThis research contributes to the present state of the art by examining changes in cross-country inequalities in digital technologies deployment and economic performance. Our empirical target builds on the hypothesis that rapid global diffusion of digital technologies unequivocally leads to gradual eradication of cross-country digital gaps and cross-country inequalities in terms of deployment of ICT; the technology convergence occurs....
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Magnetically sensitive fiber probe with nitrogen-vacancy center nanodiamonds integrated in a suspended core
PublicationEfficient collection of photoluminescence arising from spin dynamics of nitrogen vacancy (NV) centers in diamond is important for practical applications involving precise magnetic field or temperature mapping. These goals may be realized by the integration of nanodiamond particles with optical fibers and volumetric doping of the particles alongside the fiber core. That approach combines the advantages of robust axial fixation of...
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Synthesis and characterisation of polyurethane elastomers with semi-products obtained from polyurethane recycling
PublicationIn this work polyurethane elastomers were synthesised by using different mixtures of a petrochemical and glycerolysate polyols and 4,4-diphenylmethane diisocyanate (MDI). Glycerolysate polyol was produced from polyurethane foam decomposition using crude glycerine as a decomposition agent. The structure and thermal properties of obtained semi-product were similar to the polyol used in the synthesis of original foam. Glycerolysate...
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Flexible dye-sensitized solar cells based on Ti/TiO2 nanotubes photoanode and Pt-free and TCO-free counter electrode system
PublicationFlexible dye-sensitized solar cells (DSSCs) are getting more attention compared to standard glass covered DSSCs due to their unique commercial applications (e.g. tents or sail surfaces) and the possibility of rolling up into a small, portable device. In this work, titania nanotubes (TiO2 NT) modified with titania nanoparticles (TiO2 NP) were photoelectrochemically characterized as an anode for flexible dye-sensitized solar cells....
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Evaluation of the glycerolysis process and valorisation of recovered polyol in polyurethane synthesis
PublicationIn this study, the glycerolysis of polyurethane (PU) foam and the applicability of obtained glycerolysate (GLY) for cast PUs were investigated. It was found that crude glycerine with purity grade of 84% might be successfully used for the glycerolysis. The optimal conditions were determined as follows: reaction time of 60 min at 220 °C using dibutyltin dilaurate catalyst (0.5%). Moreover, the purification of GLY by means of liquid-liquid...
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Investigation on Mode I Fracture Behavior of Hybrid Fiber-Reinforced Geopolymer Composites
PublicationRecent reports in the literature have shown that fber-reinforced geopolymer composites (FRGC) made with monofbers exhibit a signifcant enhancement in fracture energy. However, many aspects of the fracture performance of hybrid fberreinforced geopolymer composites (HFRGC) remain largely unexploited, and these are predominant for the structures. For the frst time, the mode I fracture energy of HFRGC is investigated. The mode I behavior...
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The fast identification of explosives, natcotics and other chemicals carried on board of ships or transported in containers
PublicationThe fast identification of explosives, narcotics and other chemicals carried on board of ships or transported in containers to the harbors is an important problem of maritime security. Raman spectroscopy is an advanced technique used in state-of-the art laboratories for fast identification of chemicals. No sample preparation is required, and identification can be carried out through transparent packing, such as plastic or glass,...
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Preparation and characterization of TiO2 nanostructures for catalytic CO2 photoconversion
PublicationThe titanium dioxide target (99.7%) of 1 cm in dia was ablated in vacuum by laser pulses(6 ns) at 266 nm and at repetition rate of 10 Hz. During deposition the laser fluence between 1 and 3.5 J/cm2 and the O2 pressure from the range of 10-2 - 1 Pa were applied. The thin TiO2 films were deposited on glass substrate (1 × 1 cm2) heated up to 500 °C. The chemical composition of the film and samples produced by annealing were investigated...
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Thermoplastic polyurethanes with glycolysate intermediates from polyurethane waste recycling
PublicationThe polyol is a major component in polyurethane formulations and therefore introducing to the formulation recycled polyol (obtained during decomposition process) allows decreasing the usage of pure petrochemical components. In this work, thermoplastic polyurethanes were prepared using various mixtures of a petrochemical macrodiol poly(ethylene-butylene adipate)diol (PEBA) and a recycled glycolysate intermediate, called glycolysate...
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Do global brands contribute to the economy of their country of origin? A dynamic spatial approach
PublicationPurpose - Brand positioning based on the brand’s country of origin is at the centre of attention in international marketing. It is evident that global brands constitute critical intangible assets for businesses and places. However, it is not clear how they contribute to national economies. This paper aims to discuss the significance of brands as contributing to the value of their companies but also helping to leverage national...
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Heat transfer intensification by enlarged surface roughness in the plate heat exchanger
PublicationIn the paper an experimental analysis of passive heat transfer intensification technique employed in the case of the plate heat exchanger is presented. The passive intensification was obtained by a modification of the heat transfer surface. The roughness of surface was increased by a use of glass micro-beads. Single-phase convective heat transfer in the water-water system was studied. The experiment was accomplished in two stages....
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An attempt to mechanistically explain the viscoelastic behavior of transparent epoxy/starch-modified ZnO nanocomposite coatings
PublicationThe effects of bare and starch-modified ZnO (ZnO-St) nanoparticles on viscoelastic and mechanical properties are studied by dynamic mechanical and tensile analyses. Transparent epoxy-based nanocomposite films are prepared by incorporating bare or starch-modified ZnO particles into the epoxy matrix. The results demonstrated that ZnO particles hindered the curing reactions and hence the final properties of the cured epoxy. As a result,...