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Search results for: X-RAY MICRO-CT CONTINUOUS SCANNING REINFORCED CONCRETE 3-POINT BENDING SHEAR FAILURE FRACTURE
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The Influence of a Photovoltaic Micro-Installation on the Low-Frequency Parameters of Electricity at PCC and Its Impact on the Thermal Characteristics of Selected Devices
PublicationThis manuscript illustrates the measurement results of parameters describing the quality of energy at the PCC (point of common coupling) of a photovoltaic micro-installation that can significantly affect devices in the same power grid. The analyses reflecting heating of selected devices used in domestic installations, which were performed in an isolated laboratory environment, are also indicated. The conducted study aimed at checking...
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Oversizing the photovoltaic generator capacity in a micro photovoltaic plant
PublicationA significant part of photovoltaic micro installations in Poland is characterized by photovoltaic generator oversizing in relation to the inverter. The idea of oversizing, however, still raises doubts among some plant owners. In the paper, the energy yield of installation with an oversized and not oversized photovoltaic generator is presented on selected examples, showing the legitimacy of oversizing.
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Structural Properties and Water Uptake of SrTi1−xFexO3−x/2−δ
PublicationIn this work, Fe-doped strontium titanate SrTi1−xFexO3−x/2−δ, for x = 0–1 (STFx), has been fabricated and studied. The structure and microstructure analysis showed that the Fe amount in SrTi1−xFexO3−x/2−δ has a great influence on the lattice parameter and microstructure, including the porosity and grain size. Oxygen nonstoichiometry studies performed by thermogravimetry at different atmospheres showed that the Fe-rich compositions...
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Continuous Optimisation Algorithms
PublicationKsiążka poświęcona jest zagadnieniom optymalizacji ciągłej. Oprócz klasycznych algorytmów gradientowych omawiane są w współczesne algorytmy bezgradientowe, które stosowane są z powodzeniem w optymalizacji globalnej. Większość prezentowanych algorytmów określona może być mianem metaheurystycznych. Zaliczyć do nich można metody optymalizacji inspirowane procesami zachodzącymi w przyrodzie, które dalej można dzielić na inspirowane...
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Effect of Flow Normalization in Micro-Pin-Finned Heat Sink: Numerical Study
PublicationThe micro-pin-fin heat sink (MPFHS) is widely employed for the heat transfer enhancement of microchannel heat sinks. In the current paper, the effect of flow normalization on the thermohydraulic performance of micro-pin-finned heat sinks is studied numerically. Two geometries of MPFHSs, the conventional design micro-pin-fin heat sink (CD-MPFHS) with a uniform-width micro pin fin and the proposed design micro-pin-fin heat sink (PD-MPFHS)...
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Cobalt(II) tri-tert-butoxysialanethiolates.Synthesis, properties, crystal and molecular structures of [Co{SSi(OtBu)3}2(L)] and[Co{SSi(OtBu)3}2(L)2] type complexes with monodentate nitrogen ligands.
PublicationThe title heteroleptic neutral cobalt(II) tri-tert-butoxysilanethiolate complexes with monodentate nitrogen bases (L) as additional ligands have been prepared by the reactions of [Co{μ-SSi(OtBu)3}{SSi(OtBu)3}(NH3)]2 (1) with respective bases. For pyridine both types have been prepared...
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Transportable, Portable and Micro Gas Chromatographs
PublicationSignificant benefits can be obtained by miniaturization of conventional benchtop gas chromatographs. The attractive features arising from miniaturization include low-power requirements, low heat capacity of separation columns, low consumption of mobile phase, enhanced performance, higher portability, and easily coupling to detectors and secondary chromatographic systems. In separation sciences, including gas phase separations,...
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Failure analysis and modernization of high-pressure hydraulic press for drilling tubes testing
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Point to point control of fractional differential linear control systems
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Identification of continuous systems - Practical issues of insensitivity to perturbations
PublicationIn this paper the issue of continuous systems estimation, insensitive to certain perturbations, is discussed. Such an approach has rational advantages, especially when robust schemes are used to assist a target system responsible for industrial diagnostics. This requires that estimated model parameters are generated on-line, and their values are reliable and to a great extent accurate. Practical hints are suggested to challenge...
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Identification of Continuous Systems - Practical Issues of Insensitivity to Perturbations
PublicationIn this paper the issue of continuous systems estimation, insensitive to certain perturbations, is discussed. Such an approach has rational advantages, especially when robust schemes are used to assist a target system responsible for industrial diagnostics. This requires that estimated model parameters are generated on-line, and their values are reliable and to a great extent accurate. Practical hints are suggested to challenge...
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Self-compacting grout to produce two-stage concrete
PublicationTraditional concrete (TC) is primarily composed of a mixture of cement, fine and coarse aggregates, and water. TC is made by mixing together all the components before placing them. Using non-traditional concrete (two-stage concrete) to solve and to eliminate the problem of the aggregate segregation which appears in TC and in the self-compacting concrete. Two-stage concrete (TSC) consists of two main components, namely the grout...
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Buckling Analysis of a Micro Composite Plate with Nano Coating Based on the Modified Couple Stress Theory
PublicationThe present study investigates the buckling of a thick sandwich plate under the biaxial non-uniform compression using the modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for the central core the isotropic soft materials are investigated. The simplified first order shear deformation theory (S-FSDT) is employed and the governing differential...
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Failure of cold-formed beam: How does residual stress affect stability?
PublicationIn machine industry, stresses are often calculated using simple linear FEM analysis. Occasional failures of elements designed in such a way require recomputation by means of more sophisticated methods, eg. including plasticity and non-linear effects. It usually leads to investigation of failure causes and improvement of an element in order to prevent its unwanted behavior in the future. The study presents the case where both linear...
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Modelowanie wybranych własności mechanicznych struktur po-rowatych przeznaczonych na trzony długoterminowych implan-tów ortopedycznych, otrzymywanych z wykorzystaniem metod micro-CT oraz SLM
PublicationArtykuł przedstawia metodologię opracowania geometrii materiału porowatego opartego na bazie stopu tytanu. W metodologii tej dąży się do uzyskania struktury porowatej jak najbardziej zbliżonej do struktury zdrowej tkanki kostnej, bazującej na rzeczywistych modelach geometrycznych uzyskanych ze zdjęć rentgenowskich z tomografii komputerowej. Rzeczywisty materiał po odpowiedniej obróbce modelu geometrycznego oraz przy zachowaniu...
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Contribution of dynamic vehicle loads to pavement failure
PublicationPavement surfaces are not ideally even, which causes dynamic loads of vehicle axles. Distribution of dynamic loads of a given axle is similar to normal distribution and can be described by static load and dynamic load coefficient. The dynamic load coefficient depends on road profile, vehicle speed, properties of suspensions and static load of axle. While for a given road section road profile remains constant, vehicle speed and...
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Influence of selected additives and admixtures on underwater concrete and the environment
PublicationThe intensive civilization development has an influence on searching for new possibilities connected with extension of city agglomerations, both the areas of flat building and the industrial areas. One of the most interesting solution is to use water reservoirs, rivers and sea areas. The extension of buildings has an influence on building materials, especially hydrotechnical, which means development of production of hydrotechnical...
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On–line Parameter and Delay Estimation of Continuous–Time Dynamic Systems
PublicationThe problem of on-line identification of non-stationary delay systems is considered. The dynamics of supervised industrial processes are usually modeled by ordinary differential equations. Discrete-time mechanizations of continuous-time process models are implemented with the use of dedicated finite-horizon integrating filters. Least-squares and instrumental variable procedures mechanized in recursive forms are applied for simultaneous...
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ARTIFICIAL MODEL IN THE ASSESSMENT OF THE ALGORITHM OF OBJECTS RECORDED BY LASER SCANNING SHAPE DETECTION (ALS/TLS)
PublicationBrief description of the study and used methods. Brief description of the study and used As part of the preparatory work aimed to create the application solution allowing for the automation of searching objects in data, obtained in the scanning process using ALS (Airborne Laser Scanning) or TLS (Terrestrial Laser Scanning), the authors prepared a artificial (synthetic, theoretical) model of space, used for the verification of operation...
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Palm Oil Fuel Ash-Based Eco-Efficient Concrete: A Critical Review of the Short-Term Properties
PublicationThe huge demand for concrete is predicted to upsurge due to rapid construction developments. Environmental worries regarding the large amounts of carbon dioxide emanations from cement production have resulted in new ideas to develop supplemental cementing materials, aiming to decrease the cement volume required for making concrete. Palm-oil-fuel-ash (POFA) is an industrial byproduct derived from palm oil waste’s incineration in...
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Comparison of low-temperature cracks intensity on pavements with high modulus asphalt concrete and conventional asphalt concrete bases
PublicationHigh modulus asphalt concrete (HMAC) base courses provide very good resistance to rutting and fatigue but they can increase the risk of low-temperature cracking as compared with conventional asphalt concrete (AC). The article presents the comparison of these two road materials in terms of low-temperature cracking. The statistical method based on the ordered logistic regression model was used. The analysis was based on results of...
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Self-compacting grout to produce two-stage concrete
PublicationTraditional concrete (TC) is primarily composed...
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Load-carrying capacity of axially loaded concrete-filled steel tubular columns made of thin tubes
PublicationAn experimental investigation was conducted on 30 CFST columns. An influence of the following factors on load-carrying capacity of the investigated columns was analyzed: the column slenderness (l1 = 42, l2 = 27 and l3 = 15), the tube thickness (the reinforcement ratio was equal to 4% or 6%), the way of applying the load to CFST columns (through the concrete core or through the entire cross-section), the bond strength between a...
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Crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one
PublicationThe synthesis and crystal structures of (E)-3-(4-hydroxybenzylidene)chroman-4-one, C16H12O3,I, and (E)-3-(3-hydroxybenzylidene)-2-phenylchroman-4-one,C22H16O3,II, are reported. These compounds are of interest with respect to biological activity. Both structures display intermolecular C—H---O and O—H---O hydrogen bonding, forming layers in the crystal lattice. The crystal structure of compound I is consolidated...
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Analysis of Transparent Concrete as an Innovative Material Used in Civil Engineering
PublicationSince the dawn of history concrete has been, right behind stone and brick, one of the oldest building materials. The ancient Romans took advantage of its opportunities. They constructed amazing architectural objects, which survived centuries as whole buildings or parts of them. Concrete is so ubiquitous, that when we are walking in a newer districts of cities we are virtually surrounded by concrete from everywhere. Sometimes...
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Mechanical properties of sisal fiber-reinforced soybean oil-based polyurethane biocomposites
PublicationIn this paper the results of the mechanical properties of polyurethane biocomposites reinforced with short sisal fibers are presented. The fillers were added in different amount: 5, 10 and 15% by mass. Tensile test, hardness, abrasion resistance, elasticity were determined according to the standards.
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Rapid multi-objective antenna design using point-by-point Pareto set identification and local surrogate models
PublicationAntenna design is inherently a multicriterial problem.Determination of the best possible tradeoffs between conflicting objectives (a so-called Pareto front), such as reflection response, gain, and antenna size, is indispensable from the designer’s point of view, yet challenging when high-fidelity electromagnetic (EM) simulations are utilized for performance evaluation. Here, a novel and computationally...
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Degradation of stiffness of building columns exposed to bending and impact load during ground motions
PublicationThe safety of civil engineering structures under external loads, including ground motions, is one of the issues related to the idea of sustainable society. The earthquake-induced soft-storey failure is a typical type of damage observed in buildings due to seismic excitation. The failure of an intermediate soft storey of a structure results in large vertical impact loading acting on the lower floors due to the fall of the upper...
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Asynchronous Networked Estimation System for Continuous Time Stochastic Processes
PublicationIn this paper we examine an asynchronous networked estimation system for state estimation of continuous time stochastic processes. Such a system is comprised of several estimation nodes connected using a possibly incomplete communication graph. Each of the nodes uses a Kalman filter algorithm and data from a local sensor to compute local state estimates of the process under observation. It also performs data fusion of local estimates...
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CONCRETE MIX DESIGN USING ABRAMS AND BOLOMEY METHODS
PublicationOne way to reduce the consumption of cement is to optimize its use. Many known methods of concrete design, based on the Abrams law and the Bolomey method. Therefore, the authors chose those methods for analysis. The concrete composition with the assumed strength class, calculated by any method differs significantly. This applies especially to the cement content, as its content in the composition of concrete varies from 20 to 50%....
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Scanning networks with cactus topology
PublicationThe family of Pursuit and Evasion problems is widelystudied because of its numerous practical applications,ranging from communication protocols to cybernetic andphysical security. Calculating the search number of a graphis one of most commonly analyzed members of this problemfamily. The search number is the smallest number of mobileagents required to capture an invisible and arbitrarily fastfugitive, for instance piece of malicious...
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Spin-glass behavior in a binary Pr 3 Ir intermetallic compound
PublicationPolycrystalline Pr3Ir was synthesized by arc melting. Its cementite-type crystal structure (Pnma) was confirmed by powder X-ray diffraction and estimated lattice parameters are in agreement with literature. Physical properties were measured by means of the ac and dc magnetic susceptibility, electrical resistivity and heat capacity. Our results indicate spin-glass behavior in Pr3Ir with a freezing temperature Tf = 6.58 K and activation...
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Latest Achievements in Concrete Structures Three-Dimensional Printing
PublicationWe can hear about three-dimensional printed concrete structures for several years, up to date solutions in this technology allow entire printing settlements of tiny concrete houses. Due to technical limitations, these houses are still small and not very durable, but undoubtedly, this technology is developing. Home printed in three-dimensional technology can be an alternative to modular container buildings implemented in areas affected...
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As- built inventory of the office building with the use of terrestrial laser scanning
PublicationTerrestrial Laser Scanning (TLS) is an efficient tool for building inventories. Based on the red- laser beam technology it is possible to provide the high accuracy data with complete spatial information about a scanned object. In this article, authors present the solution of use a TLS in as-built inventory of the office building. Based on the provided data, it is possible to evaluate the correctness of built details of a building...
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Configurations of H 3 + (H2)n clusters and their energies
PublicationThe H-3(+) ion plays an important role in low temperature astrophysical and laboratory plasmas. It is considered as the initiator of many ion-molecule chemistries. Also its clusters with H-2 are quite interesting. We study configurations of the H-3(+)(H-2)(n) clusters for n = 1 up to n = 12 as a simple test system. Total energies for these structures, with zero point vibration corrections have been calculated. Stabilization energies...
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Partially prestressed concrete beams with bonded and unbonded strands
PublicationThis article relate the tests of partially prestressed concrete beams. There is presented the research programme - geometry of elements, method of loading, the materials and variables. There have been shown preliminary test results of prestressed concrete elements with bonded and unbonded strands, and compared to the test results of R.C. beam.
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Determination of representative volume element in concrete under tensile deformation
PublicationW artykule podano sposoby określenia elementu reprezentatywnej objętości w betonie podczas rozciągania. Obliczenia wykonano przy zastosowaniu izotropowego modelu degradacji sztywności rozszerzonego o długość charakterystyczną mikrostruktury w ramach teorii nielokalnej. Zaproponowano 2 różne metody wyznaczania elementu reprezentatywnej objętości niezależnego od warunków brzegowych.
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Optimization algorithm and filtration using the adaptive TIN model at the stage of initial processing of the ALS point cloud
PublicationAirborne laser scanning (ALS) provides survey results in the form of a point cloud. The ALS point cloud is a source of data used primarily for constructing a digital terrain model (DTM). To generate a DTM, the set of ALS observations must be first subjected to the point cloud processing methodology. A standard methodology is composed of the following stages: acquisition of the ALS data, initial processing (including filtration),...
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Distributed Representations Based on Geometric Algebra: the Continuous Model
PublicationAuthors revise the concept of a distributed representation of data as well as two previously developed models: Holographic Reduced Representation (HRR) and Binary Spatter Codes (BSC). A Geometric Analogue (GAc - ''c'' stands for continuous as opposed to its discrete version) of HRR is introduced - it employs role-filler binding based on geometric products. Atomic objects are real-valued vectors in n-dimensional Euclidean space...
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Model-Based Adaptive Machine Learning Approach in Concrete Mix Design
PublicationConcrete mix design is one of the most critical issues in concrete technology. This process aims to create a concrete mix which helps deliver concrete with desired features and quality. Contemporary requirements for concrete concern not only its structural properties, but also increasingly its production process and environmental friendliness, forcing concrete producers to use both chemically and technologically complex concrete...
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Green engineered biomaterials for bone repair and regeneration: Printing technologies and fracture analysis
PublicationDespite the exceptional self-regeneration properties of bone, severe injuries often require additional surgical intervention such as using artificial bone constructs. These structures need to meet a number of criteria regarding their structure, performance, alongside the rate and the mechanism of erosion and fracture when implanted, for stimulating the regeneration of defected bone and, more critically providing support in the...
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Fixed point indices of iterated smooth maps in arbitrary dimension
PublicationWe give a complete description of possible sequences ofindices of iterations of f at an isolated fixed point, answering inaffirmative the Chow, Mallet-Paret and Yorke conjecture posed in[S.N. Chow, J. Mallet-Parret, J.A. Yorke, A periodic point index whichis a bifurcation invariant, in: Geometric Dynamics, Rio de Janeiro,1981, in: Lecture Notes in Math., vol. 1007, Springer, Berlin, 1983,pp. 109-131].
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N-point estimators of the Instantaneous Complex Frequency
PublicationIn this paper estimators of the instantaneous complex frequency (ICF) are presented and discussed. The differential approach for the estimation of the ICF is used, therefore the estimators are based on maximally flat N-point FIR filters: differential and delay. The investigation of the filter performance includes static characteristics of ICF estimation and the error of the ICF estimation in the discrete frequency domain.W pracy...
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Numerical Study of Concrete Mesostructure Effect on Lamb Wave Propagation
PublicationThe article presents the results of the numerical investigation of Lamb wave propagation in concrete plates while taking into account the complex concrete mesostructure. Several concrete models with randomly distributed aggregates were generated with the use of the Monte Carlo method. The influence of aggregate ratio and particle size on dispersion curves representing Lamb wave modes was analyzed. The results obtained for heterogeneous...
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3. Ceramika budowlana
PublicationW rozdziale 3 pięciotomowej monografii omówiono wyroby ceramiczne: wyroby z ceramiki porowatej, wyroby o strukturze spieczonej, wyroby fajansowe i porcelanowe, materiały ogniotrwałe, produkcję wyrobów ceramicznych. W szerokim zakresie przedstawiono badania wyrobów ceramicznych.
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An advanced tool integrating failure and sensitivity analysis into novel modeling of the stormwater flood volume
PublicationAn innovative tool for modeling the specific flood volume was presented that can be applied to assess the need for stormwater network modernization as well as for advanced flood risk assessment. Field measurements for a catchment area in Kielce, Poland, were used to apply the model and demonstrate its usefulness. This model extends the capability of recently developed statistical and machine learning hydrodynamic models developed...
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Mechanism of Isomerization and Acid-Induced Transformations of 3-Hydroxy-4,4'-dimethoxy-3'-methyl-3-oxo-7,7'-bis(piperidino-carbonyloxy)-2,2'-spirobi-[2H,2'H,3H,3'H-benzo[b]thiophene]. Unusual Equilibrium between the Spiro and 3-Hydroxy-benzothiophene Systems.
PublicationStwierdzono, że 3'-hydroksy-4,4'-dimetoksy-3'-metylo-3-okso-7,7'-bis(piperydynokarbonyloksy)-2,2'-spirobi[2H,2'H,3H,3'H-benzo[b]tiofen] występuje w roztworach postaci mieszaniny dwóch diastereoizomerów pozostających w dynamicznej równowadze. Mechanizm tej równowagi oparty jest na odwracalnym otwarciu pierścienia z 1,5 przeniesieniem protonu i utworzeniu przjściowej formy 3-hydroksybenzotiofenu.
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SU‐GG‐T‐208: 3‐D Dosimetric Comparison of IMRT with 2.5 Mm HD120 MLC Using Optical CT Based Polymer Gel and PRESAGE Dosimeters
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Evaluation and rationale of the performance of several elastomeric composites incorporating devulcanized EPDM
Publicationthylene Propylene Diene rubber (EPDM), is present in many applications. However, its crosslinked structure makes difficult its recycling. The use of devulcanized EPDM, (dEPDM) as a component of elastomeric composites, is a real possibility to reuse EPDM scraps. In this study, three matrices (natural rubber (NR), styrene butadiene rubber (SBR) and EPDM rubber) have been tested including devulcanized EPDM as a recycled component....
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Monitoring of concrete curing in extradosed bridge supported by numerical simulation
PublicationThe paper describes a mathematical model of concrete curing taking into account kinetics of setting reactions. The numerical model is implemented in the author’s program that was used to monitor thermal effects recorded in the concrete bottom plate of the extradosed bridge. Numerical approach was verified by experimental measurements and used for assessment of the current compressive strength due to degree of hydration of fresh...