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Search results for: GEOMETRICAL DISPASION
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Examples of numerical simulations of two-dimensional unsaturated flow with VS2DI code using different interblock conductivity averaging schemes
PublicationFlow in unsaturated porous media is commonly described by the Richards equation. This equation is strongly nonlinear due to interrelationships between water pressure head (negative in unsaturated conditions), water content and hydraulic conductivity. The accuracy of numerical solution of the Richards equation often depends on the method used to estimate average hydraulic conductivity between neighboring nodes or cells of the numerical...
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Influence of nonlinearities on the efficiency and accuracy of FEM calculations on the example of a steel build-up thin-walled column
PublicationDue to the increase of computing capabilities of standard processing units, it is possible to perform complex analyses, considering a number of nonlinearities, such as geometric, material and boundary (contact) even on personal computers. In the paper, the authors have analysed the efficiency and accuracy of standard PC’s FEM calculations performed in Abaqus CAE 2017 software on the example of a critical load assessment of a thin-walled...
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Computer-aided evaluation of the railway track geometry on the basis of satellite measurements
PublicationIn recent years, all over the world there has been a period of intensive development of GNSS (Global Navigation Satellite Systems) measurement techniques and their extension for the purpose of their applications in the field of surveying and navigation. Moreover, in many countries a rising trend in the development of rail transportation systems has been noticed. In this paper, a method of railway track geometry assessment based...
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The symmetric extendibility of quantum states
PublicationStudies on the symmetric extendibility of quantum states have become particularly important in the context of the analysis of one-way quantum measures of entanglement, and the distillability and security of quantum protocols. In this paper we analyze composite systems containing a symmetric extendible part, with particular attention devoted to the one-way security of such systems. Further, we introduce a new one-way entanglement...
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Jumping Wave Characteristic during Low Plasticity Burnishing Process
PublicationDuring the low plasticity burnishing process of soft materials such as carbon steel with a hardness of up to 40 HRC (Rockwell grade) a raised structure of the material known as the Jumping Wave forms in front of the tool roll. This phenomenon significantly disturbs the burnishing process, but is very poorly described in the literature. This article presents studies of this phenomenon on the example of burnished 1.0562 steel. The...
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(CsX)Cu5O2(PO4)2 (X = Cl, Br, I): A Family of Cu2+ S = 1/2 Compounds with Capped-Kagomé Networks Composed of OCu4 Units
PublicationThree new salt inclusion compounds (CsX)Cu5O2(PO4)2 (X = Cl, Br, I), phosphate analogues of the kagomé mineral averievite, are reported. Their crystal structures are composed of trigonal networks of corner-sharing OCu4 anion-centered tetrahedra, forming capped-kagomé planes, which can also be regarded as two-dimensional slices along the [111] direction of a pyrochlore lattice. Magnetization and heat capacity measurements reveal...
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Application of linear buckling sensitivity analysis to economic design of cylindrical steel silos composed of corrugated sheets and columns
PublicationThe paper deals with global stability of steel cylindrical silos composed of corrugated walls and vertical columns with loads imposed by a bulk solid following Eurocode 1. The optimum silo design with respect to the steel weight was based on a sensitivity analysis method. The changes of silo column profiles at each design step were performed by means of influence lines for the buckling load factor due to the unit column bending...
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Syntetyczne wskaźniki oceny stanu toru
PublicationJakość geometryczna toru analizowana jest w różnych celach, a dane podlegają różnemu stopniowi agregacji. Pojedyncze nierówności toru analizowane są zazwyczaj z uwagi na bezpieczeństwo i służą do planowanie napraw w krótkich terminach. Natomiast agregacja pomierzonych parametrów pozwala na planowanie robót w terminach średniookresowych i budowę modeli predykcji. W artykule przedstawiono zagregowane wskaźniki jakości geometrycznej...
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Nonlinear finite element modeling of vibration control of plane rod-type structural members with integrated piezoelectric patches
PublicationThis paper addresses modeling and finite element analysis of the transient large-amplitude vibration response of thin rod-type structures (e.g., plane curved beams, arches, ring shells) and its control by integrated piezoelectric layers. A geometrically nonlinear finite beam element for the analysis of piezolaminated structures is developed that is based on the Bernoulli hypothesis and the assumptions of small strains and finite...
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Effect of surface on the flexomagnetic response of ferroic composite nanostructures; nonlinear bending analysis
PublicationOur analysis incorporates the geometrically nonlinear bending of the Euler-Bernoulli ferromagnetic nanobeam accounting for a size-dependent model through assuming surface effects. In the framework of the flexomagnetic phenomenon, the large deflections are investigated referring to von-Kármán nonlinearity. Employing the nonlocal effects of stress coupled to the gradient of strain generates a scale-dependent Hookean stress-strain...
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Stabilizing forces in trapezoidal sheeting used as a part of the bracing system
PublicationIn the analysis of bracing systems imperfections of the restrained elements should be considered. According to EC3 this effect can be calculated by means of the equivalent stabilizing force, which replaces (in simplified way) initial bow imperfection of the braced element. However, alternative suggestions of the equivalent stabilizing force calculations can be also found in the literature. In this paper segment of the pitched roof...
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Stabilizing forces in trapezoidal sheeting used as a part of the bracing system
PublicationIn the analysis of bracing systems imperfections of the restrained elements should be considered. According to EC3 this effect can be calculated by means of the equivalent stabilizing force, which replaces (in simplified way) initial bow imperfection of the braced element. However, alternative suggestions of the equivalent stabilizing force calculations can be also found in the literature. In this paper segment of the pitched roof...
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Size effect in concrete beams under bending – influence of the boundary layer and the numerical description of cracks
PublicationIn the paper the size effect phenomenon in concrete is analysed. The results of numerical simulations of using FEM on geometrically similar un-notched and notched concrete beams under bending are presented. Concrete beams of four different sizes and five different notch heights under three-point bending test were simulated. In total 18 beams were analysed. Two approaches were used to describe cracks in concrete. First, eXtended...
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Uniwersalny program komputerowy do projektowania zmiany kierunku trasy
PublicationW pracy przedstawiono kolejny program komputerowy stanowiący implementację algorytmu obliczeniowego dotyczącego projektowania zmiany kierunku trasy kolejowej, dostosowanego do techniki ciągłych pomiarów satelitarnych. Program ten ma charakter uniwersalny, gdyż w ogólnym przypadku obejmuje wprowadzenie do układu geometrycznego dwóch łuków kołowych o różnym promieniu, czyli zastosowanie łuku koszowego. Może się to okazać szczególnie...
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Schemat powstawania rys na przykładzie osiowo rozciąganego pręta żelbetowego
PublicationW artykule przedstawiono w sposób schematyczny ideę powstawania kolejnych rys w konstrukcjach żelbetowych na przykładzie osiowo rozciąganego pręta. Opisano początkowy oraz końcowy stan zarysowania. Wyprowadzono wzór na szerokość rysy. Przedstawiono interpretację geometryczną rys dla fazy początkowego zarysowania oraz efekt tension stiffening na przykładzie elementu osiowo rozciąganego. Przedstawiono przykładowe obliczenia miary...
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Modification of thermal and rheological characteristics of bitumen by waste PET/GTR blends
PublicationWaste poly(ethylene terephthalate) (wPET)/ground tire rubber (GTR) blends with variable compositions were applied as low-cost modifiers into bitumen and their performance has been evaluated via morphological, thermal and rheological analyses. Depending on the weight ratio of wPET/GTR, dispersion of single/composite domains of waste polymers in the bitumen has promoted the interaction between bitumen and blend components. Fourier...
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Numerical Simulations and Tracer Studies as a Tool to Support Water Circulation Modeling in Breeding Reservoirs
PublicationThe article presents a proposal of a method for computer-aided design and analysis of breeding reservoirs in zoos and aquariums. The method applied involves the use of computer simulations of water circulation in breeding pools. A mathematical model of a pool was developed, and a tracer study was carried out. A simplified model of two-dimensional flow in the form of a biharmonic equation for the stream function (converted into...
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Assessment of microstructure, physical and thermal properties of bitumen modified with LDPE/GTR/elastomer ternary blends
PublicationLDPE/GTR/elastomer ternary blends with variable LDPE/GTR ratio and constant elastomer content were prepared via melt-compounding. Obtained LDPE/GTR/elastomer blends were applied as thermoplastic modifiers into bitumen. Microstructure, physical and thermal properties of the modified bitumen were determined. It was observed that chemical composition of LDPE/GTR/elastomer blends has significant influence on their density and rheological...
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Tribological Properties of Ni-P/Si3N4 Nanocomposite Layers Deposited by Chemical Reduction Method on Aluminum Alloy AW-7075
PublicationThe article presents the results of tribological tests of Ni-P/Si3N4 nanocomposite and Ni-P nickel layers deposited on the AW-7075 aluminum alloy by chemical reduction method, and the AW-7075 alloy without coating. Nanocomposite layers were produced using Si3N4 siliconnitride in the form of a polydisperse powder whose particle sizes ranged from 20 to 25 nm. The influence of the content of the dispersion phase layer material on...
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Effect of double thermal and electrochemical oxidation on titanium alloys for medical applications
PublicationThe research focuses on the development and characterization of innovative thin hybrid oxide coatings obtained in subsequent processes of thermal (TO) and electrochemical (EO) oxidation. Four different surface modifications were investigated and the microstructure was determined, the mechanical, chemical and biological properties of the Ti-13Nb-13Zr alloy were assessed using scanning electron microscopy, X-ray dispersion analysis,...
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Copper Slag as a Potential Waste Filler for Polyethylene-Based Composites Manufacturing
PublicationThe present study aimed to analyze the application of waste material from copper production– copper slag (ŻŻL) as filler for composites based on the high-density polyethylene (HDPE). Copper slag filler was introduced in the amounts of 1–20 wt%, and its influence on the appearance (color analysis), chemical structure (Fourier-transform infrared (FTIR) spectroscopy), microstructure (optical microscopy), as well as static (tensile...
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The interaction of the pulsed laser irradiation with titania nanotubes - Theoretical studies on the thermal effect
PublicationThis paper reports temperature dispersion simulations of titania nanotubes irradiated by the 355 nm, pulsed, nanosecond laser. The modelling with the use of Finite Elements Method concerns titania nanotubes of the length and the wall thickness in the range of 0.5–2 μm and 5–20 nm, respectively. The uniqueness of the morphology was preserved by ensuring the wall thickness variation along the height of the tube, which was determined...
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Improved Bandwidth of Microstrip Wide-Slot Antenna Using Gielis Curves
PublicationThe development of a broadband printed wide-slot antenna based on Gielis curves is presented in this article. The printed wide-slot antenna can be conveniently reshaped to achieve ultra-wideband performance by using superformula. The distinct advantage of employing the superformula in design of wide-slot antenna lies in its ability to define nearly any geometric shape including non-standard, complex and non-intuitive for the wide-slot...
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Comparison of Average Energy Slope Estimation Formulas for One-dimensional Steady Gradually Varied Flow
PublicationTo find the steady flow water surface profile, it is possible to use Bernoulli’s equation, which is a discrete form of the differential energy equation. Such an approach requires the average energy slope between cross-sections to be estimated. In the literature, many methods are proposed for estimating the average energy slope in this case, such as the arithmetic mean, resulting in the standard step method, the harmonic mean and...
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Badania obszarów zagrożonych zniszczeniem w biomateriałach koron stomatologicznych
PublicationDo analizy obszarów zagrożonych zniszczeniem w biomateriałach koron stomatologicznych zastosowano analizę strukturalną elementów skończonych MES. Opracowano dwu wymiarowy model korony stomatologicznej zamocowanej na kikucie zęba, w którym określono obszary występowania poszczególnych materiałów. Przyjęte do obliczeń numerycznych wartości modułu Younga i współczynniki Poissona odniesiono do rzeczywistych biomateriałów korony stomatologicznej....
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Parametrized Local Reduced-Order Models With Compressed Projection Basis for Fast Parameter-Dependent Finite-Element Analysis
PublicationThis paper proposes an automated parametric local model-order reduction scheme for the expedited design of microwave devices using the full-wave finite-element method (FEM). The approach proposed here results in parameterized reduced-order models (ROMs) that account for the geometry and material variation in the selected subregion of the structure. In each subregion, a parameter-dependent projection basis is generated by concatenating...
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Electric transport in organic system with planar DBP/F16ZnPc junction on the basis of direct current and small signal admittance spectra analysis
PublicationThe objective of this work was to determine electric transport in the organic device based on a planar junction of electron donor and electron acceptor materials, namely ITO/MoO3/DBP/F16ZnPc/BCP/Ag. The analysis reported herein was based on direct current-voltage measurements and small-signal admittance spectra in the dark and under illumination. Such analysis may provide information on potential barriers, parasitic resistances...
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Experience Based Decisional DNA (DDNA) to Support Sustainable Product Design
PublicationThis paper presents the idea of providing engineering design knowledge to designers working on sustainable product design and development process. The new product development process often requires significant amount of design knowledge which can be saved and recalled by designers during the design process. This knowledge is very important for successful sustainable product development as it can include material selection, product...
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NON-LINE ANALYSIS OF STIFFNESS IN COMPRESSION CONDITIONS
PublicationThe analyzes were aimed at demonstrating the influence of parameters describing the deformation of the structure on the uncertainty of critical force, and the impact of technological imperfections on stress uncertainty in compression conditions. In a linear buckling analysis, the problem is considered only for the initial, permanent state of the stiffness matrix. In the case of demonstrating the influence of initial deformations...
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THE APPLICATION OF KALMAN FILTERING TO PREDICT VERTICAL RAIL AXIS DISPLACEMENTS OF THE OVERHEAD CRANE BEING A COMPONENT OF SEAPORT TRANSPORT STRUCTURE
PublicationAs the devices designed to transport materials, the overhead cranes should meet certain geometric requirements for their operation to be safe. The presently available geodetic equipment, in particular total stations, provides opportunities for precise 3D measurements of coordinates of the controlled points. These coordinates make a basis for correcting the height of crane runway axes. The paper presents a method to calculate position...
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Verification of GNSS Measurements of the Railway Track Using Standard Techniques for Determining Coordinates
PublicationThe problem of the reproduction of the railway geometric layout in the global spatial system is currently solved in the form of measurements that use geodetic railway networks and also, in recent years, efficient methods of mobile positioning (mainly satellite and inert). The team of authors from the Gdańsk University of Technology and the Maritime University in Gdynia as part of the research project InnoSatTrack is looking for...
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Mobile Cloud computing architecture for massively parallelizablegeometric computation
PublicationCloud Computing is one of the most disruptive technologies of this century. This technology has been widely adopted in many areas of the society. In the field of manufacturing industry, it can be used to provide advantages in the execution of the complex geometric computation algorithms involved on CAD/CAM processes. The idea proposed in this research consists in outsourcing part of the load to be com- puted in the client machines...
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Analysis of ultimate compressive strength of cracked plates with the use of DOE techniques
PublicationThe objective of this work is to investigate the structural compressive response of plates with locked cracks accounting for all relevant factors and correlation between them. The nonlinear FE model considering both geometric and material nonlinearities is employed herein, and the FE model of the structural response of intact plates is validated with the available experimental data. In the common studies, based on One Factor at...
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Axial capacity of steel built-up battened columns
PublicationThis paper deals with the numerical investigation aimed to study the axial capacity of pin-ended steel built-up columns. Three methods of calculating forces in chords and batten, taking into account the material and geometric imperfections specified in the Eurocode 3 are considered. The aim of this study was to compare different methods allowing the calculation of the column load capacity and determine a simpler and faster method...
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Reduced-cost surrogate modelling of compact microwave components by two-level kriging interpolation
PublicationFull-wave electromagnetic (EM) analysis is a versatile tool for evaluating the performance of high-frequency components. Its potential drawback is its high computational cost, inhibiting the execution of EM-driven tasks requiring massive simulations. The applicability of equivalent network models is limited owing to the topological complexity of compact microstrip components because of EM cross-coupling effects. Development of...
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Do Leonardo da Vinci’s drawings, room acoustics and radio astronomy have anything in common?
PublicationAfter introducing Leonardo da Vinci’s (LdV) predecessors in the field of light propagation research, his drawings on the topic of reflecting light by a spherical mirror are analysed. The discovery of LdV is presented, according to which, at an infinitely distant source of rays, a small fragment of the canopy is enough to generate a focus, while the rest of the mirror forms a caustic for which LdV did not indicate an application....
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Pomiar ryzyka bankowego - propozycja typologii
PublicationW artykule zaproponowano typologię pomiaru ryzyk bankowych. Wyodrębnione kryteria podziału podejść do pomiaru ryzyka to: (1) pomiar bezpośredni/pośredni, (2) pomiar ex post/ex ante, (3) kryterium oparte o składnik ryzyka – częstotliwość, dotkliwość, ekspozycja, całościowa strata, (4) kryterium oparte o parametr rozkładu: pomiar wartości oczekiwanej/przeciętnej, pomiar rozproszenia, pomiar wartości skrajnych. Wśród motywów pomiaru...
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The Ellenbogen's “Matter as Software” Concept for Quantum Computer Implementation. C60 and X@C60 Molecules as Available Molecular Building Blocks (MBBs) for Tip-Based Nanofabrication (TBN) of Quantum Computing Devices
PublicationThe TBN bottom-up strategy of building quantum devices from C60 and X@C60 MBBs is proposed as an extension of the Ellenbogen's “Matter as Software” idea to quantum information processing. The capped SW or DW CNT STM tip is considered as device for manipulating C60 and X@C60 molecules. In this article, the possibility of using easily available on the market C60 Fullerene and endohedral X@C60 molecules together with commercial CNT...
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Stateczność samopodnoszących pełnomorskich platform wiertniczych w fazie eksploatacji
PublicationWspółczynnik bezpieczeństwa platformy Petrobaltic na moment obrotowy (stateczność ogólna) oszacowany przy założeniu, że konstrukcja jest traktowana jako układ słupów połączonych sztywnym pokładem, z korekcją efektów drugiego rzędu. Przemieszczenie poziome pokładu platformy wyznaczone, stosując odpowiedni model MES. Siła krytyczna nogi obliczona przy założeniu jej utwierdzenia w dnie morza. Wpływ odchyłki od idealnej geometrii rur...
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Quantitative assessment of the influence of tensile softening of concrete in beams under bending by numerical simulations with XFEM and cohesive cracks
PublicationResults of the numerical simulations of the size effect phenomenon for concrete in comparison with experimental data are presented. In-plane geometrically similar notched and unnotched beams under three-point bending are analyzed. EXtended Finite Element Method (XFEM) with a cohesive softening law is used. Comprehensive parametric study with the respect to the tensile strength and the initial fracture energy is performed. Sensitivity...
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On some problems in determining tensile parameters of concrete model from size effect tests
PublicationThe paper presents results of numerical simulations of size effect phenomenon in concrete specimens. The behaviour of in-plane geometrically similar notched and unnotched beams under three-point bending is investigated. In total 18 beams are analysed. Concrete beams of four different sizes and five different notch to depth ratios are simulated. Two methods are applied to describe cracks. First, an elasto-plastic constitutive law...
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Monitoring wizyjny w systemach zabezpieczenia transportu wodnego. Koncepcja implementacyjna
PublicationW artykule autorzy przedstawiają koncepcję zastosowania własnych badań nad pomiarem prędkości przepływu cieczy do zastosowań praktycznych w pomiarach przepływu wody w kanałach otwartych i rzekach. Jako narzędzie pomiarowe wykorzystują zestaw aparatów synchronicznych, które rejestrują indykatory przepływu znajdujące się na powierzchni analizowanej cieczy. Aparat matematyczny przedstawiony w rozwiązaniu sprowadza się do stosowania...
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Price convergence in the EU-an aggregate and disaggregate approach
PublicationThis article examines the price dispersion in the European Union (EU) over 15 years (1990-2005). An extensive overview of the literature offers inconclusive results with the half-lives of price shocks from 2.8 to 282 months. Until now, most of the empirical research has been either micro or macro based. In contrast, we conducted a complex analysis utilizing both aggregate and disaggregate price data. The macro approach is based...
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Optoelectronic properties of curved carbon systems
PublicationSystematic investigation of optoelectronic properties of curved carbon systems has been performed and the results have been compared with the representatives of flat carbon systems. Moreover, the application of third order dispersion corrected density functional tight binding method (with third order corrections of self-consistent charges) including Becke-Johnson dumping (DFTB3-D3(BJ)) has been validated in order to obtain reliable...
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The Sonocatalytic Activation of Persulfates on Iron Nanoparticle Decorated Zeolite for the Degradation of 1,4-Dioxane in Aquatic Environments
PublicationIn the chemical industry, 1,4-diethylene dioxide, commonly called dioxane, is widely used as a solvent as well as a stabilizing agent for chlorinated solvents. Due to its high miscibility, dioxane is a ubiquitous water contaminant. This study investigates the effectiveness of catalyst- and ultrasound (US)-assisted persulfate (PS) activation with regard to degrading dioxane. As a first step, a composite catalyst was prepared using...
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Quality Modeling in Grid and Volunteer-Computing Systems
PublicationA model of computational quality in large-scale computing systems was presented in the previous chapter of this book. This model describes three quality attributes: performance, reliability and energy efficiency. We assumed that all processes in the system are incessantly ready to perform calculations and that communication between the processes occurs immediately. These assumptions are not true for grid and volunteer computing...
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Preparation and characterisation of solution-cast Nafion membrane
PublicationNafion is a commercial name for a perfluorosulfonic polymer, which has been developed in 1962 by Dupont de Nemours. This polymer consists of a polytetrafluoroethylene backbone and regular spaced long perfluorovinyl ether pendant side chains terminated by a sulfonate ionic group. These sulfonate groups are responsible for cation-exchange properties of Nafion. Thanks to the ion-exchange properties, water permeability, good chemical,...
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Graphene Oxide as Mine of Knowledge: Using Graphene Oxide To Teach Undergraduate Students Core Chemistry and Nanotechnology Concepts
PublicationThe aim of this laboratory experiment is to utilize graphene oxide (GO) material to introduce under-graduate students to many well-known concepts of general chemistry. GO is a new nanomaterial that has generated worldwide interest and can be easily produced in every well-equipped undergraduate chemical laboratory. An in-depth examination of GO synthesis, as well as a study of its structure and properties, allows students to familiarize...
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Fabrication of La-Doped Bi4Ti3O12 Ceramics
PublicationLa-modified Bi4Ti3O12 is a typical ferroelectric, piezoelectric and electro-optic material, having relatively low coercive field, low dielectric constant, high Curie temperature and high breakdown strength. Goal of the present research was to apply mixed oxide method for fabrication of BiTLax ceramics, study its chemical composition, crystalline structure and microstructure. The compound BiTLax for x=0, 0.25, 0.5, 0.75 ceramic...
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Capping ligand initiated CuInS2 quantum dots decoration on, ZnIn2S4 microspheres surface under different alkalinity levels resulting in different hydrogen evolution performance
PublicationSurface distribution of quantum dots (QDs) at the semiconductor matrix caused by synthesis condition (e.g. pH of solution during coupling) could lead to different photocatalytic activity. Thus, achieving an optimal covering of semiconductor matrix by QDs has been challenging. Herein, the influence of the alkalinity level of aqueous decoration medium for the coupling of mercaptoundecanoic acid (MUA) capped CuInS2 quantum dots (CIS)...