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Search results for: TWO-DIMENSIONAL GAS CHROMATOGRAPHY
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Infrared techniques for natural convection investigations in channels between two vertical, parallel, isothermal and symmetrically heated plates
PublicationThe effect of the gap width between two symmetrically heated vertical, parallel, isothermal plates on intensity of natural convective heat transfer in a gas (Pr = 0.71) was experimentally studied using the balance and gradient methods. In the former method heat fluxes were determined based on measurements of the voltage and electric current supplying the heaters placed inside the walls. In the latter, heat fluxes were calculated...
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Voice command recognition using hybrid genetic algorithm
PublicationAbstract: Speech recognition is a process of converting the acoustic signal into a set of words, whereas voice command recognition consists in the correct identification of voice commands, usually single words. Voice command recognition systems are widely used in the military, control systems, electronic devices, such as cellular phones, or by people with disabilities (e.g., for controlling a wheelchair or operating a computer...
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CO2 capture through direct-contact condensation in a spray ejector condenser and T- junction separator
PublicationThe design principle underlying the steam condensation and CO2 purification in a gas power plant with a focus on reducing CO2 emissions encompasses the deployment of a spray ejector condenser (SEC) and separator. This innovative system facilitates direct-contact condensation of steam with non-condensable gas (CO2) by inter acting with a spray of subcooled water, seamlessly integrated with a T-junction separator mechanism aimed...
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KRYTERIA STOSOWANE W WIELOKRYTERIALNYM PLANOWANIU ROZWOJU SYSTEMU ELEKTROENERGETYCZNEGO
PublicationProblematyka planowania rozwoju systemów elektroenergetycznych jest zagadnieniem często podejmowanym w badaniach optymalizacyjnych ze względu na wagę i zasięg problemu. Rozwój techniki komputerowej pozwolił na połączenie tematyki optymalizacji struktury wytwarzania i planowania sieci elektroenergetycznej, co jest zagadnieniem wielowątkowym oraz wielowymiarowym. W prezentowanym artykule przedstawiono kryteria stosowane w analizach...
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Numerical analysis of vacuum drying of a porous body in the integrated domain
Publicationn the present study, the vacuum drying process of an apple slice is numerically modeled based on a control volume method. Transient two-dimensional Navier– Stokes, energy, moisture, and Luikov equations are solved by numerical coding (Fortran) to simulate the simultaneous heat and mass transfer in the ambient and apple slice, respectively. The privilege of using Luikov's model is that the capillary forces are considered, and a...
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Modelling hydraulic and capillary-driven two-phase fluid flow in unsaturated concretes at the meso-scale with a unique coupled DEM-CFD technique
PublicationThe goal of the research was to demonstrate the impact of thin porous interfacial transition zones (ITZs) between aggregates and cement matrix on fluid flow in unsaturated concrete caused by hydraulic/capillary pressure. To demonstrate this impact, a novel coupled approach to simulate the two-phase (water and moist air) flow of hydraulically and capillary-driven fluid in unsaturated concrete was developed. By merging the discrete...
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Comparison of classical and modern approach of determination of highly polar compounds by High Performance Liquid Chromatography coupled with Tandem Mass Spectrometry
PublicationAbstract: Sugars and sugar alcohols are known as highly polar compounds. Four analytes were taken into consideration for comparison of classical and modern approach of separation of highly polar substances. Mannitol was chosen as an example of simple sugar alcohol, sucrose and lactulose as examples of disaccharides and structural isomers, raffinose as an example of complex trisaccharide. Raffinose was also used as internal standard...
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Evolving gene regulatory networks controlling foraging strategies of prey and predators in an artificial ecosystem
PublicationCo-evolution of predators and prey is an example of an evolutionary arms race, leading in nature to selective pressures in positive feedback. We introduce here an artificial life ecosystem in which such positive feedback can emerge. This ecosystem consists of a 2-dimensional liquid environment and animats controlled by evolving artificial gene regulatory networks encoded in linear genomes. The genes in the genome encode chemical...
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Damage Imaging in Lamb Wave-Based Inspection of Adhesive Joints
PublicationAdhesive bonding has become increasingly important in many industries. Non-destructive inspection of adhesive joints is essential for the condition assessment and maintenance of a structure containing such joints. The aim of this paper was the experimental investigation of the damage identification of a single lap adhesive joint of metal plate-like structures. Nine joints with different defects in the form of partial debonding...
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Investigation of Narrow Transverse and Longitudinal Electrostatic Precipitators
PublicationDiesel engines emit fine particles, which are harmful to human and animal health. There are several methods for decrease particulate emission from a diesel engines, but up to now, these methods are not enough effective or very expensive. An electrostatic precipitation was proposed as an alternative method for control of a diesel particulate emission. Therefore, narrow electrostatic precipitators (ESPs) have become a subject of...
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Determination of time dependence of coated metal electrical and electrochemical parameters during exposure using principal component analysis
PublicationThe use of the principal component analysis (PCA) permits the complex and quantitative analysis of the time dependence of electrical and electrochemical parameters of coated metal obtained by fitting impedance data. So far, changes in electrical and electrochemical parameters during exposure were analyzed independently. In this way, some of the information contained in the relationship between changes in parameters over time are...
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Optimization of Stabilizing Systems in Protection of Cultural Heritage: The Case of the Historical Retaining Wall in the Wisłoujście Fortress
PublicationThe aim of the paper is to propose new quantitative criteria for selecting the optimal method of securing and repairing a historical object, which take into account Structural, Conservation and Architectural aspects (the S–C–A method). Construction works on cultural heritage sites tend to be challenging and require an interdisciplinary approach. Therefore, they are strictly related to the philosophy of sustainable development which...
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Minichannel and minigap classification criteria based on the aspect ratio of the minigeometry: A numerical study
PublicationA detailed numerical investigation has been carried out to analyze the diabatic flow distribution and velocity profile in 18 minigeometries with various aspect ratios for V-type and I-type flow configurations (for 36 cases) assuming ethanol as a working fluid. The aim of the study is to distinguish the value of the aspect ratio for which the flow in minigeometry starts to be two-dimensional (minigap). Cases with a constant Reynolds...
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Global Complex Roots and Poles Finding Algorithm in C × R Domain
PublicationAn algorithm to find the roots and poles of a complex function depending on two arguments (one complex and one real) is proposed. Such problems are common in many fields of science for instance in electromagnetism, acoustics, stability analyses, spectroscopy, optics, and elementary particle physics. The proposed technique belongs to the class of global algorithms, gives a full picture of solutions in a fixed region ⊂ C × R and...
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An intelligent cellular automaton scheme for modelling forest fires
PublicationForest fires have devastating consequences for the environment, the economy and human lives. Understanding their dynamics is therefore crucial for planning the resources allocated to combat them effectively. In a world where the incidence of such phenomena is increasing every year, the demand for efficient and accurate computational models is becoming increasingly necessary. In this study, we perform a revision of an initial proposal...
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Simulations of hydro-fracking in rock mass at meso-scale using fully coupled DEM/CFD approach
PublicationThe paper deals with two-dimensional (2D) numerical modelling of hydro-fracking (hydraulic fracturing) in rocks at the meso-scale. A numerical model was developed to characterize the properties of fluid-driven fractures in rocks by combining the discrete element method (DEM) with computational fluid dynamics (CFD). The mechanical behaviour of the rock matrix was simulated with DEM and the behaviour of the fracturing fluid flow...
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EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF CONCRETE BEHAVIOUR AT MESO-LEVEL DURING QUASI-STATIC SPLITTING TENSION
PublicationThe paper describes experimental and numerical results of quasi-static splitting tensile tests on concrete specimens at meso-scale level. The loading strip was made of plywood or steel. Fracture in concrete was detected at the aggregate level by means of three non-destructive methods: 3D x-ray micro-computed tomography, 2D scanning electron microscope and manual 2D digital microscope. The discrete element method was used to directly...
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Conversion of Biomass and Municipal Wastes into Syngas and Hydrogen using Highly Preheated Agent (HTAG)
PublicationGasification is considered to be one of the most promising energy recovery technologies for the widespread utilization of biomass and wastes. During this process raw feedstock is converted into a combustible gas, which can then be burnt to produce thermal energy, or to run engines for mechanical or electrical power. The studies of biomass gasification demonstrate it as a friendly alternative to fossil fuels as one of renewable...
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The Application of Fluidic Sealing in Shrouded Gas Turbine Blades
PublicationThis paper presents a study conducted on a new gas turbine designed to limit leakage in the labyrinth seal. The slots in the fin are used to generate a bypass flow, which obstructs the flow in the gap above the fin. The method was tested numerically and experimentally beforehand using a simplified model without rotation or blade passages. In this paper, the validation of the method using a model of a turbine stage is shown. Reynolds-averaged...
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Foamed Polyurethane Composites With Different Types of Ash – Morphological, Mechanical and Thermal Behavior Assessments
Publicationncorporation of two types of ash particles into flexible polyurethane foams has been investigated, wood ash from gasification process and fly ash resulting from coal burning in power plant. Samples were modified with 5, 10 and 15 wt% of fillers. Structure, mechanical and thermal properties of obtained foams were investigated. Incorporation of both types of ash particles resulted in materials showing...
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Searching for Solvents with an Increased Carbon Dioxide Solubility Using Multivariate Statistics
PublicationIonic liquids (ILs) are used in various fields of chemistry. One of them is CO2 capture, a process that is quite well described. The solubility of CO2 in ILs can be used as a model to investigate gas absorption processes. The aim is to find the relationships between the solubility of CO2 and other variables—physicochemical properties and parameters related to greenness. In this study, 12 variables are used to describe a dataset...
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Comparative study of a combined heat and power plant retrofitted by CO2 capture during the combustion of syngas from sewage sludge gasification versus zero-emission combustion of hydrogen produced using renewables
PublicationWith ecological requirements aimed at limiting the production of CO2, it is necessary to produce all, or most of the energy from RES. During the transformation process, ecological and highly efficient combustion power plants will be needed. The classic cycle of combined heat and power (CCGT) with green improvements will continue to be one of the most suitable technologies for this task. This article presents the modernization of...
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The Analysis of Overall Ship Fuel Consumption in Acceleration Manoeuvre using Hull-Propeller-Engine Interaction Principles and Governor Features
PublicationThe problem of reduction of greenhouse gas emissions in shipping is currently addressed by many research works and related industries. There are many existing and visionary technologies and ideas, which are conceptually defined or practically realised. This goal can be achieved in different ways, and reducing fuel consumption is one of the major methods. In these circumstances, the aim of this study is to analyse the possibility...
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Technology of an adhesive silicone film as drug carrier in transdermal therapy I. Analytical methods used for characterization and design of the universal elastomer layers
PublicationSilicone polymers possess unique properties, which make them suitable for many different applications, for example in the pharmaceutical and medical industry. To create an adhesive silicone film, the appropriate silicone components have to be chosen first. From these components two layers were made: an adhesive elastomer applied on the skin, and a non-adhesive elastomer on the other side of the film. The aim of this study was...
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Design and Microwave-Assisted Synthesis of TiO2-Lanthanides Systems and Evaluation of Photocatalytic Activity under UV-LED Light Irradiation
PublicationThe TiO2-Eu and TiO2-La systems were successfully synthesized using the microwave method. Based on the results of X-ray diffraction analysis, it was found that regardless of the analyzed systems, two crystal structures were noted for the obtained samples: anatase and rutile. The analysis, such as XPS and EDS, proved that the doped lanthanum and europium nano-particles are present only on the TiO2 surface without disturbing the...
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Organic Supercritical Thermodynamic Cycles with Isothermal Turbine
PublicationOrganic Rankine cycles (ORC) are quite popular, but the overall efficiencies of these plants are rather very low. Numerous studies have been conducted in many scientific centers and research centers to improve the efficiency of such cycles. The research concerns both the modification of the cycle and the increase in the parameters of the medium at the inlet to the turbine. However, the efficiency of even these modified cycles rarely...
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Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite
PublicationIn this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography–mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane...
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‘Green’ multi - residue methods for the determination of high importance currently used pesticides in environmental samples
PublicationThe purpose of the research has been to develop and apply ‘green’ analytical methodologies to control and monitor the level of currently used pesticides from different chemical groups in aqueous samples. For extraction of analytes solid - phase microextraction (SPME) and dispersive liquid - liquid microextraction (DLLME) have been applied and compared. For SPME, commonly used materials for coating fibers include: polydimethylsiloxane...
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Investigation on air quality of specific indoor environments—spa salons located in Gdynia, Poland
PublicationDue to excessive application of essential oils and scented products in spa salons during aromatherapy and massage sessions, the elevated concentration of total volatile organic compounds (TVOCs), particularly terpenes, which are known as secondary organic aerosol (SOA) precursors, is expected there. This study was aimed at determination of VOCs with a particular regard to terpenes in air samples collected in selected spa salons...
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The effect of aeration mode (intermittent vs. continuous) on nutrient removal and greenhouse gas emissions in the wastewater treatment plant of Corleone (Italy)
PublicationThe paper reports the results of an experimental study aimed at comparing two configurations of a full-scale wastewater treatment plant (WWTP): conventional activated sludge (CAS) and oxic-settling-anaerobic process (OSA) with intermittent aeration (IA). A comprehensive monitoring campaign was carried out to assess multiple parameters for comparing the two configurations: carbon and nutrient removal, greenhouse gas emissions, respirometric...
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Speech Analytics Based on Machine Learning
PublicationIn this chapter, the process of speech data preparation for machine learning is discussed in detail. Examples of speech analytics methods applied to phonemes and allophones are shown. Further, an approach to automatic phoneme recognition involving optimized parametrization and a classifier belonging to machine learning algorithms is discussed. Feature vectors are built on the basis of descriptors coming from the music information...
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Structural properties of foil bearings: a closed-form solution validated with finite element analysis
PublicationFluid film thickness in a compliant foil bearing is greatly influenced by the deflection of the bearing structure. Therefore, in order to properly model performance of a foil bearing, it is mandatory that the deflection of the compliant bearing structure due to the generated hydrodynamic pressure is determined accurately. This article proposes an easy-to-use two-dimensional model, which takes into account detailed geometry of the...
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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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Numerical Simulation of Catastrophic Flood: the Case Study of Hypothetical Failure of the Bielkowo Hydro–Power Plant Reservoir
PublicationThe numerical modeling of flood wave propagation following the hypo-thetical breaks of the embankments of the Bielkowo hydro–power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland have been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating...
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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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Effects of Column Base Flexibility on Seismic Response of Steel Moment-Frame Buildings
PublicationSteel Moment Resisting Frames (SMRFs) are very popular lateral load resisting systems in many seismically active regions. However, their seismic response is strongly dependent on the rotational fixity of column base connections. Despite many studies (both experimental and numerical) in this particular area, available approaches for estimating column base flexibility have been validated only against laboratory test data. In the...
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Unusual divergence of magnetoacoustic beams
PublicationTwo-dimensional magnetosonic beams directed along a line forming a constant angle h with the equilibrium straight magnetic field are considered. Perturbations in a plasma are described by the system of ideal magnetohydrodynamic equations. The dynamics of perturbations in a beam are different in the cases of fast and slow modes, and it is determined by h and equilibrium parameters of a plasma. In particular, a beam divergence may...
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Quasi-Global Optimization of Antenna Structures Using Principal Components and Affine Subspace-Spanned Surrogates
PublicationParametric optimization is a mandatory step in the design of contemporary antenna structures. Conceptual development can only provide rough initial designs that have to be further tuned, often extensively. Given the topological complexity of modern antennas, the design closure necessarily involves full-wave electromagnetic (EM) simulations and—in many cases—global search procedures. Both factors make antenna optimization a computationally...
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Automatic Breath Analysis System Using Convolutional Neural Networks
PublicationDiseases related to the human respiratory system have always been a burden for the entire society. The situation has become particularly difficult now after the outbreak of the COVID-19 pandemic. Even now, however, it is common for people to consult their doctor too late, after the disease has developed. To protect patients from severe disease, it is recommended that any symptoms disturbing the respiratory system be detected as...
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A Novel Approach to Fully Nonlinear Mathematical Modeling of Tectonic Plates
PublicationThe motion of the Earth's layers due to internal pressures is simulated in this research with an efficient mathematical model. The Earth, which revolves around its axis of rotation and is under internal pressure, will change the shape and displacement of the internal layers and tectonic plates. Applied mathematical models are based on a new approach to shell theory involving both two and three-dimensional approaches. It is the...
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Automatic Breath Analysis System Using Convolutional Neural Networks
PublicationDiseases related to the human respiratory system have always been a burden for the entire society. The situation has become particularly difficult now after the outbreak of the COVID-19 pandemic. Even now, however, it is not uncommon for people to consult their doctor too late, after the disease has developed. To protect patients from severe disease, it is recommended that any symptoms disturbing the respiratory system be detected...
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A model development and experimental verification for a vapour microturbine with a permanent magnet synchronous generator
PublicationVapour microturbines with permanent magnet synchronous generators are implemented in micropower plants for dispersed power generation systems. The dynamic model of such a microturbine set was developed and presented. The developed relations result from the generic equations. Experimental data for two different working medium were used for model verification. A microturbine set model was tested during the changes in the parameters...
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Use of pyridinium and pyrrolidinium ionic liquids for removal of toluene from gas streams
PublicationSeparation of toluene from a toluene/N2 gas mixture using supported liquid membranes based on a series of pyridinium (1-butylpyridinium- bis(trifluoromethylsulfonyl)imide - [C4Py][Tf2N], 1-hexylpyridinium trifluoromethanesulfone [C6Py][Tf2N]) and pyrrolidinium (1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C4Pyrr][Tf2N], 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide - [C6Pyrr][Tf2N], 1-butyl-1-methylpyrrolidinium...
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Influence of Holes Manufacture Technology on Perforated Plate Aerodynamics
PublicationTranspiration flow is a very important and still open subject in many technical applications. Perforated walls are useful for the purpose of “flow control”, as well as for the cooling of walls and blades (effusive cooling) in gas turbines. We are still not able to include large numbers of holes in the numerical calculations and therefore we need physical models. Problems are related also to the quality of the holes in perforated...
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Analysis of exhaled breath for dengue disease detection by low-cost electronic nose system
PublicationThis paper presents a procedure and a set-up of an electronic nose system analyzing exhaled breath to detect the patients suffering from dengue – a mosquito-borne tropical disease. Low-power resistive gas sensors (MiCS-6814, TGS8100) were used to detect volatile organic compounds (VOCs) in the exhaled breath. The end-tidal phase of patients exhaled breath was collected with a BioVOCTM breath sampler. Two strategies were assessed...
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Metals and metal-binding ligands in wine: Analytical challenges in identification.
PublicationBackground Due to important role of metals in the vinification process as well as their impact on the human health, their content in this alcoholic beverage has been extensively studied by many researchers. It is already known that speciation of metals determines their toxicity and bioavailability as well as influences their activity. Understanding the chemistry and knowing the structures of metal complexes could have relevant...
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Bio‑derived polyurethanes obtained by non‑isocyanate route using polyol‑based bis(cyclic carbonate)s—studies on thermal decomposition behavior
PublicationNon-isocyanate polyurethanes (NIPUs) constitute one of the most prospective groups of eco-friendly materials based on their phosgene-free synthesis pathway. Moreover, one of the steps of their obtaining includes the use of carbon dioxide (CO 2 ), which allows for the promotion of the development of carbon dioxide capture and storage technologies. In this work, non- isocyanate polyurethanes were obtained via three-step synthesis...
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Implementation of Solute Transport in the Vadose Zone into the “HYDRUS Package for MODFLOW”
PublicationThe “HYDRUS package for MODFLOW” is an existing MODFLOW package that allows MODFLOW to simultaneously evaluate transient water flow in both unsaturated and saturated zones. The package is based on incorporating parts of the HYDRUS‐1D model (to simulate unsaturated water flow in the vadose zone) into MODFLOW (to simulate saturated groundwater flow). The coupled model is effective in addressing spatially variable saturated‐unsaturated...
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On Fast Multi-objective Optimization of Antenna Structures Using Pareto Front Triangulation and Inverse Surrogates
PublicationDesign of contemporary antenna systems is a challenging endeavor, where conceptual developments and initial parametric studies, interleaved with topology evolution, are followed by a meticulous adjustment of the structure dimensions. The latter is necessary to boost the antenna performance as much as possible, and often requires handling several and often conflicting objectives, pertinent to both electrical and field properties...
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Steady magnetohydrodynamic flow in a diverging channel with suction or blowing
PublicationAn analysis is made of steady two-dimensional divergent flow of an electrically conducting incompressible viscous fluid in a channel formed by two non-parallel walls, the flow being caused by a source of fluid volume at the intersection of the walls. The fluid is permeated by a magnetic field produced by an electric current along the line of intersection of the channel walls. The walls are porous and subjected to either suction...