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Search results for: POWER BALANCE
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Hybridized SVPWM Algorithm for Multilevel CHB Inverter With DC-Link Voltage Control Capability
PublicationThe deployment of a space vector pulsewidth modulation (SVPWM) scheme in controlling cascaded H-bridge multilevel inverter (CHB MLI) is quite challenging; especially, when a substantial number of output voltage levels are involved and the dc-link voltages are out of balance. In this article, a simple SVPWM algorithm for CHB MLI is proposed. In the proposed algorithm, all the H-bridges in an inverter phase are treated as a single...
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Strategies for achieving energy neutrality in biological nutrient removal systems - a case study of the Slupsk WWTP (northern Poland)
PublicationThe paper presents a model-based evaluation of technological upgrades on the energy and cost balance in a large biological nutrient removal wastewater treatment plant (WWTP) in the city of Slupsk (northern Poland). The proposed upgrades include chemically enhanced primary sludge removal and reduction of the nitrogen load in the deammonification process employed for reject water treatment. Simulations enabled to estimate the increased...
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Strategies for Achieving Energy Neutrality in Biological Nutrient Removal Systems – a Case Study of the Slupsk WWTP (northern Poland)
PublicationThe paper presents a model-based evaluation of technological upgrades on the energy and cost balance in a large biological nutrient removal wastewater treatment plant (WWTP) in the city of Slupsk (northern Poland). The proposed upgrades include chemically enhanced primary sludge removal and reduction of the nitrogen load in the deammonification process employed for reject water treatment. Simulations enabled to estimate the increased...
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Analysis of balancing of four stroke V6 engines
PublicationAnalysis of balance of V6 engines with a common-pin crankshaft depending on a cylinder bank angle and the crank radius to connecting rod length ratios , based on the relations derived, is presented in the paper. The bank angles providing the lowest moment of inertia forces in reciprocating motion, for selected values, were determined. The position of the plane of the main counterweights in order to maximum balance of the moment...
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The Dynamics of Trade Relations between Ukraine and Romania: Modelling and Forecasting
PublicationThe article examines the monthly dynamics of exports, imports and balance of trade between Ukraine and Romania in the period from 2005 to 2021. Time series from 2015 to 2021 were used for modelling and forecasting (since the date the European Union–Ukraine Association Agreement took effect). Adequate models of the dynamics series of the Box-Jenkins methodology were built: additive models with seasonal component ARIMA (Autoregressive...
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Team Roles and Team Performance in Small Virtual Software Teams
PublicationThe article presents the results of research on the composition of team roles conducted in 24 student software teams. An adaptation of M. Belbin’s model by B. Kożusznik was used. The model of team balance according to Belbin and Haaf is presented and correlations between team balance and team performance are analysed. Team performance is measured at three levels: result, satisfaction and team climate. The selected constellation...
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The migration policy of Armenia
PublicationAbstract: The aim of this study is to describe the legal bases of the migration policy of Armenia and its practical implementation in 1995–2013. The author examined the international and national documents that provide the legal bases of Armenia’s migration policy, as well as the balance between departures and arrivals in the period 1995–2013, Armenian citizens’ reasons for emigrating and the occupations of emigrants. The study...
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Balancing Energy Inputs/Outputs and GHG Emissions for Sustainable Wastewater Treatment – a Case Study
PublicationThe aim of the study is a model-based evaluation of the selected operating modes and technological upgrades on the energy balance and greenhouse gas (GHG) emissions in a large wastewater treatment plant in the city of Slupsk (northern Poland). The considered scenarios focus on energy savings for aeration, increasing energy recovery via biogas cogeneration and reduction of the CO2 equivalent emission from both direct processes (related...
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Flood Routing by the Non-Linear Muskingum Model: Conservation of Mass and Momentum
PublicationIn this paper, the conservative properties of the Muskingum equation, commonly applied to solve river flood routing, are analysed. The aim of this analysis is to explain the causes ofthe mass balance error, which is observed in the numerical solutions of its non-linear form. The linear Muskingum model has been considered as a semi-discrete form of the kinematic wave equation and therefore it was possible to derive its two non-linear...
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Determination of dryout localization using a five-equation model of annular flow for boiling in minichannels
PublicationDetailed studies have suggested that the critical heat flux in the form of dryout in minichannels occurs when the combined effects of entrainment, deposition, and evaporation of the film make the film flow rate go gradually and smoothly to zero. Most approaches so far used the mass balance equation for the liquid film with appropriate formulations for the rate of deposition and entrainment respectively. It must be acknowledged...
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Silent Signals The Covert Network Shaping the Future
PublicationSilent Signals The Covert Network Shaping the Future In a world dominated by information flow and rapid technological advancements, the existence of hidden networks and unseen influences has never been more relevant. "Silent Signals: The Covert Network Shaping the Future" delves deep into the mysterious and often opaque world of covert communication networks. This influential work sheds light on the silent...
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Model of pressure distribution in vortex flow controls
PublicationThe paper is devoted to the vortex valve. Existing devices are described by CFD-methods, or by means of simple empirical relations. A rational method of the considered object design is proposed, on the base of the input and dissipation energy balance., what gives a simple algebraic equation. Conformity between calcul;ated and measured parameters of the vortex valve allows for acceptation of the proposed concept.
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Design and Evaluation of the Platform for Weight-Shifting Exercises with Compensatory Forces Monitoring
PublicationDetails of a platform for the rehabilitation of people with severe balance impairment are discussed in the paper. Based upon a commercially available static parapodium, modified to fit force sensors, this device is designed to give a new, safe tool to physiotherapists. It is designed for the patients who cannot maintain equilibrium during a bipedal stance and need to hold to or lean on something during the rehabilitation. Visual,...
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Actual and reference evapotranspiration for a natural, temperate zone fen wetland – Upper Biebrza case study
PublicationEvapotranspiration is the key and predominant component of the water balance in wetlands. Direct evapotranspiration measurements are challenging in wetlands due to their remoteness and high surface water level. This article describes the actual (ETa and reference evapotranspiration (ET0) from a cultivated wet meadow located in the Biebrza National Park – the largest national park in north-east Poland, Central Europe. The data were...
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Free-surface elevation in open vortex flow controls
PublicationRotational form of fluid motion is complex, but very important in science and technology. The paper is devoted to the hydraulic mechanism of flow in open vortex flow controls, or regulators. The velocity field was described by the kinematic model, and intensity of rotation - by means of the energy balance between the input and dissipation. In consequence some algebraic expresions were obtained, which can be useful in approximated...
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Anthropopressure’s intensification with reference to Arctic ecosystems
PublicationThis paper concerns issue of long range atmospheric transport of pollutants to polar areas and intensification of their toxic effect on biota in the face of climate change. Arctic which was for years seen as a pristine and not affected by antropopressure region became a sink of xenobiotics. Atmospheric circulation facilitates transport of chemicals from Eurasia to Arctic. Influence of climate change on crucial balance of polar...
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Risk sharing in the construction work contracts
PublicationBy signing a contract for construction works each of the parties assumes a specific scope of responsibility. In practice, there are numerous examples of contractual provisions that violate the parties’ safety and the balance of fair and even distribution of risk. Asymmetry in risk allocation in construction contracts and its consequences is the most common cause of disputes between the parties. The article presents the issue of...
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The Influence of Co-Fermentation of Agri-Food Waste with Primary Sludge on Biogas Production and Composition of the Liquid Fraction of Digestate
PublicationEnergy self-sufficiency is a current trend in wastewater treatment plants. This effect can be achieved by increasing the production of electricity from biogas and by reducing energy consumption for technological processes. One idea, in line with the circular economy concept, is the use of waste rich in organic matter as co-substrates for the fermentation process. The aim of this study was to determine the effect of waste co-fermentation...
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Arctic as a reservoir for polycyclic aromatic hydrocarbons and polychlorinated biphenyls- water samples from Foxfonna glacier
PublicationPolycyclic aromatic hydrocarbons and polychlorinated biphenyls are groups of stable compounds, hard to biodegrade, potentially toxic. Their presence in Arctic environment may have a big impact on natural balance, fauna and flora. Although Arctic areas should be unpolluted, some amounts of pollutants are transferred from lower latitudes with sea currents and air masses. This paper presents the amounts of selected persistent organic...
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ZEUS Concept and Its Wider European Application
PublicationThe objectives of the ZEUS project and the resulting concept of an integrated system of transport safety are recapitulated in the article. The context for transport safety management that has evolved since this became a concern of the European Union under the Treaty of Union in 1993 is outlined, and some issues related to applying the ZEUS concept across Europe are discussed. It is concluded that there is scope for exploring ways...
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Preliminary Testing of the Influence of Modified Polycaprolactones on Anabaena Variabilis Growth in Seawater
PublicationSeveral new biodegradable polymer materials have recently come onto the global market. Mostly the results on degradation kinetic studies are presented. This paper suggests using one of the tests to estimate the impact of polymer packaging material on sea life. The microorganism chosen was Anabaena variabilis (identified in many waters, including those of the Baltic Sea, especially in the Gulf of Gdansk and Puck Bay; this cyanobacterium...
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Informal employment in Poland: an empirical spatial analysis
PublicationThe main goal of our article is to bridge the gap in the regional analysis of informal employment in Poland and in particular to indicate the propensity for informal work in the working-age population, to test if informal activities are typical for marginalized people (less educated, unemployed, older) and to identify the regional and spatial heterogeneity in the propensity. We use data from the ‘Human Capital Balance 2010–2014’...
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Insights into Stoichiometry Adjustments Governing the Performance of Flexible Foamed Polyurethane/Ground Tire Rubber Composites
PublicationPolyurethanes (PU) are widely applied in the industry due to their tunable performance adjusted by changes in the isocyanate index—stoichiometric balance between isocyanate and hydroxyl groups. This balance is affected by the incorporation of modifiers of fillers into the PU matrix and is especially crucial for PU foams due to the additional role of isocyanates—foaming of the material. Despite the awareness of the issue underlined...
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Design criterion for hydrodynamic vortex separators
PublicationTechnical objects designing involves determination of geometrical parameters that characterize a given object. When the device is described by the differential equations, an inverse problem brings difficulties, as geometrical values sought condition the solution to the problem. Vortex separators can be designed by the "criterion method'. Firstly, a critical particle is distinguished such that bigger particles are removed from...
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Experimental study of boiling heat transfer in the stagnation point of water microjet
PublicationIn the paper presented is a comparison of computational model with experimental data. Numerical model of liquid film with phase change in the stagnation zone due to impingement of the microjet is more widely presented in authors previous work. The radius on which theevaporation process is taking place can be determined from the energy balance on the element of the plate. That radius has also been confirmed experimentally in the...
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The Attitude of Polish Entrepreneurs to the Fact of Staging the Mega Sport Event - the Case of Pomeranian SMEs Towards Euro 2012
PublicationIn the course of preparations to the 2012 European Football Championship (Euro 2012) many doubts have arisen as to the actual cost-benefit balance affecting the hosting country. The event is accompanied by intense promotion of the agglomeration and the region, especially abroad. In effect, one can anticipate the competitive position of both the region and the businesses operating there to improve. The investigation whether the...
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Nonlinear resultant theory of shells accounting for thermodiffusion
PublicationThe complete nonlinear resultant 2D model of shell thermodiffusion is developed. All 2D balance laws and the entropy imbalance are formulated by direct through-the-thickness integration of respective 3D laws of continuum thermodiffusion. This leads to a more rich thermodynamic structure of our 2D model with several additional 2D fields not present in the 3D parent model. Constitutive equations of elastic thermodiffusive shells...
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GIUSEPPE VOLPI. IL GRANDE MEDIATORE TRA ISTITUZIONI, POLITICA ED ECONOMIA
PublicationGiuseppe Volpi di Misurata represented a mediation point between different interests both in the economic field and in the complex national – but also regional and local – political balance that long underpinned the fascist regime. This article intends to revisit this figure between the 1920s and the Second World War. The attempt will be made to identify, through an approach that will be chronological and thematic, the passages...
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A Clustering-Based Methodology for Selection of Fault Tolerance Techniques
PublicationDevelopment of dependable applications requires selection of appropriate fault tolerance techniques that balance efficiency in fault handling and resulting consequences, such as increased development cost or performance degradation. This paper describes an advisory system that recommends fault tolerance techniques considering specified development and runtime application attributes. In the selection process, we use the K-means...
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International Competitiveness of Czech Manufacturing: A Sectoral Approach with Error Correction Model
PublicationThe main objective of this paper is to find the determinants of the international competitiveness of the manufacturing sectors of the Czech economy, using the database of 13 manufacturing subsectors in 1995–2011, with the aid of ECM model. The authors research the question of how much foreign and domestic demand, the level of labour costs, the level of sector innovation intensity, the level of sector openness to foreign markets...
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Structure and Randomness in Planning and Reinforcement Learning
PublicationPlanning in large state spaces inevitably needs to balance the depth and breadth of the search. It has a crucial impact on the performance of a planner and most manage this interplay implicitly. We present a novel method \textit{Shoot Tree Search (STS)}, which makes it possible to control this trade-off more explicitly. Our algorithm can be understood as an interpolation between two celebrated search mechanisms: MCTS and random...
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A Concept of Automatic Film Color Grading Based on Music Recognition and Evoked Emotions
PublicationThe article presents the aspects of the final selection of the color of shots in film production based on the psychology of color. First of all, the elements of color processing, contrast, saturation or white balance in the film shots were presented and the definition of color grading was given. In the second part of the article the analysis of film music was conducted in the context of stimulating appropriate emotions while watching...
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Analysis of the Water Level Variation in the Polish Part of the Vistula Lagoon (Baltic Sea) and Estimation of Water Inflow and Outflow Transport through the Strait of Baltiysk in the Years 2008–2017
PublicationThe Vistula Lagoon is located in both Poland and Russia along the southern coast of the Baltic Sea. It is connected to the Baltic Sea in the Russian part by the Strait of Baltiysk. The purpose of the paper is to identify the dominant factors underlying the water level variation mechanism at Tolkmicko in the Vistula Lagoon, revealed by a statistical analysis of the measured data and a discussion on the inflow and outflow transport...
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Revision of Biological Methods for Determination of EDC Presence and Their Endocrine Potential
PublicationEndocrine-disrupting compounds (EDC) are chemicals responsible for disturbances in the hormonal balance of organisms. This group of chemicals includes both egzogenic and endogenic substances or their mixtures that impact functioning of natural hormones in organisms. In the available literature one can find information on the application of chromatographic and related techniques in the analysis of environmental samples for detection,...
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Poland's economic relations with Kazakhstan
PublicationBefore 2019, economic relations between Poland and Kazakhstan were regulated by 22 international agreements. Poland has been trading with Kazakhstan since the 1990s. Overall, Kazakhstan had a positive trade balance with Poland, with the exception of the 1996–1998 and 2006–2007 periods. Polish foreign investment in Kazakhstan was not very impressive; the first investments started only in 2005. In 2019, about 200 companies with Polish...
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Application of vertical flow constructed wetlands for highly contaminated wastewater treatment: preliminary results
PublicationBasing on quantitative and qualitative characteristics of reject waters (RWC) generated during dewatering of digested sewage sludge on centrifuges in conventional WWTP and municipal landfill leachate (LL), the pilot constructed wetlands for treatment of both types wastewater were designed and built. In the paper the conception, design and assumed treatment efficiencies of the pilot plants are presented. The water balance of the...
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Relationship between heart rate variability, blood pressure and arterial wall properties during air and oxygen breathing in healthy subjects
PublicationPrevious studies reported that normobaric hyperoxia influences heart rate, arterial pressure, cardiac output and systemic vascular resistance, but the mechanisms underlying these changes are still not fully understood. Several factors are considered including degeneration of endothelium-derived nitric oxide by reactive oxygen species, the impact of oxygen-free radicals on tissues and alterations of autonomic nervous system function....
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The Impact of Isocyanate Index and Filler Functionalities on the Performance of Flexible Foamed Polyurethane/Ground Tire Rubber Composites
PublicationThe structure and performance of polyurethane (PU) foams are strongly driven by the stoichiometry of the polyaddition reaction, quantitatively described by the isocyanate index. It determines the balance between isocyanate and hydroxyl groups in the reacting system and is affected by the introduction of additional functionalities originated, e.g., from applied fillers. Nevertheless, this issue is hardly taken into account in research...
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Aggregation of nonionic surfactants in imidazolium ionic liquids
PublicationMicellar aggregation of surfactants in aqueous solutions has been described in terms of the balance between dispersive interactions of the hydrocarbon part of the amphiphilic molecule, and the hydration and electrostatic repulsive effects of hydrophilic head group. Changing the interactions by replacing water with another polar solvent, such as amides or glycols, has been studied to a smaller extent (Singh, Saleem et al. 1980;...
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Preeclampsia Risk Prediction Using Machine Learning Methods Trained on Synthetic Data
PublicationThis paper describes a research study that investigates the use of machine learning algorithms on synthetic data to classify the risk of developing preeclampsia by pregnant women. Synthetic datasets were generated based on parameter distributions from three real patient studies. Four models were compared: XGBoost, Support Vector Machine (SVM), Random Forest, and Explainable Boosting Machines (EBM). The study found that the XGBoost...
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Urban Freight Transport Demand Modelling and Data Availability Constraints
PublicationThe paper provides a review of urban freight transport demand modelling approaches confronted with constrains regarding adequate data provision from a perspective of the local authorities. Demand estimation models has been selected as a reference because they are the most representative in terms of inclusion of urban freight indicators which can be transformed into a decision-support tool for evaluation of freight measures. The...
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Virtual immersive environments
PublicationYet a higher level of active systems may be achieved when users are fully immersed in an interface which is a 3D computer generated virtual world and can interact with surrounding objects of that world as they were in a real one. This is the issue covered by Chapter 7. Interaction in such a world is both multidimensional and multimodal, with the possibility of free movement of the user in any direction and the simultaneous stimulation...
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Labour resources in Azerbeijan
PublicationThe article aims to assess the changes of the Azerbaijani labour resources through deductive analysis of historical data and observation of changes in the structure of resources based on generally available macroeconomic data. Analysis shows that, during the period considered, the population of Azerbaijan increased, with a majority living in cities. Universal access to education enabled a growing group of Azerbaijanis to complete...
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The influence of sound track on the viewer’s emotions and correction of the color in the film
PublicationThe article presents the aspects of the final selection of colors in film production based on the emotions caused by the soundtrack of the film. First, the processing of colors, contrast, saturation and white balance of shots in the film was presented. The definition of color grading is also described, i.e. the color changes in the film's views. In the second part of the article, the soundtracks of the film were analyzed, in particular...
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Miniaturization-Oriented Design of Spline-Parameterized UWB Antenna for In-Door Positioning Applications
PublicationDesign of ultra-wideband antennas for in-door localization applications is a challenging task. It involves development of geometry that maintains appropriate balance between the size and performance. In this work, a topologically-flexible monopole has been generated using a stratified framework which embeds a gradient-based trust-region (TR) optimization algorithm in a meta-loop that gradually increases the structure dimensionality....
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Angle Tracking Observer for Filtering Rotor Position Estimates in Sensorless Electric Drives
PublicationSensorless electric drives use measurements of electrical quantities to estimate rotor position and speed. Measurement errors deteriorate the estimation accuracy, thus additional means are necessary to remove high-frequency components from estimated signals. This paper proposes to use an Angle Tracking Observer (ATO) for reducing noise in rotor position estimates, which is related to random errors in the measurements. A simplified,...
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Pilot study of the influence of thermoplastic starch based polymer packaging material on the growth of diatom population in sea water environment
PublicationNovel polymeric packaging materials susceptible to environmentally friendly decomposition appeared on the global market. The paper is devoted to an investigation of the impact of degradable polymer packaging on marine life. The chosen polymer was a commercial packaging based on thermoplastic starch (TPS over 85%). The microorganism chosen was Phaeodactylum tricornutum diatom (identified in many aquatic reservoirs, with a tendency...
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Can Historic Interiors with Large Cubature be Turned Acoustically Correct?
PublicationHistoric interiors with large cubature, such as reception, theatrical, and concert halls, need to be renovated periodically if they are to be preserved as cultural heritage for future generations. In such cases it is necessary to maintain appropriate balance between requirements imposed by heritage conservation authorities office which are usually being given a higher priority, applicable safety regulations, and the comfort of...
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Retention modeling of some saccharides separated on an amino column.
PublicationUsing an amino column (Supelcosil LC-NH2) and different mixtures of acetonitrile-water, quantitative structure-retention relationship models are discussed. These models are based on computed molecular descriptors representing numerically structured features of some saccharides. The obtained results are underlining the lipophilicity/hydrophilicity balance, and how this is controlling the separation of the saccharides. The resulting...
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A comprehensive approach to SBR modelling for monitoring and control system design
PublicationThe aim of this research is to provide a comprehensive description of the Sequencing Batch Reactor (SBR) modelling for monitoring, control, and plant operational optimisation validation. The paper provides a detailed modelling of the SBR, its components and constituent processes. For this purpose, the mass balance principle and continuity equations were provided with a reactive term implemented using Activated Sludge Model (ASM)....