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Quadratic Cohen representations in spectral analysis of serration process in Al–Mg alloys
PublicationImportant from mechanical point of view the Portevin–Le Chatelier serration phenomenon is being characterized by a complicated spectral profile. As a typical example of nonstationary processes it demands a special treatment allowing to follow the evolution of energy of stress fluctuations as a function of strain. The authors suggest the utilization of a compact system of quadratic transformations, known as Cohen class, as a technique...
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Autonomous Battery Drive in Trolleybuses: an Overview of Practical Examples
PublicationBattery electric buses are believed to be means of transportation of the future. However, despite the continuous development of electrochemical batteries technology and the multitude of electric buses on offer, it is still no proved solutions that can be widely used. Charging is the one of the weakness point of the electric buses. Trolleybuses are alternative for them. Especially, trolleybuses equipment with traction batteries...
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Influence of preprocessing techniques on pulse pressure velocity determination
PublicationPulse Wave Velocity (PWV) is measured and utilized in many clinical applications. Recently, a wide research has been led to develop a cuff-less and continuous blood pressure method basing on PWV. However, in this application a decision on choosing an appropriate fiducial point of pulse wave (PW) waveform is necessary and substantial. It would allow to measure time parameters necessary to determine PWV. An influence of sampling...
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The circle object detection with the use of Msplit estimation
PublicationThe paper presents the use of Msplit(q) - estimation in the filtration and aggregation of point clouds containing a known number of elliptical shapes with preliminary unknown - locations and dimensions. These theoretical solutions may have practical relevance especially in the modelling of terrestrial laser scanning data of objects that have similar shape to circles. Mentioned shapes can be scanned of tree trunks, columns, gutters,...
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Integrable zero-range potentials in a plane
PublicationWe examine general statements in the Wronskian representation of Darboux transformations for plane zero-range potentials. Such expressions naturally contain scattering problem solution. We also apply Abel theorem to Wronskians for differential equations and link it to chain equations for Darboux transforms to fix conditions for further development of the underlying distribution concept. Moutard transformations give a convenient...
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Expedite EM-driven generation of Pareto-optimal trade-off curves for variable-turn on-chip inductors
PublicationThis work presents a novel approach to computationally efficient Pareto front identification for variable-turn on-chip inductors. The final outcome is a set of solutions that correspond to the best trade-offs between conflicting design objectives. Here, we consider minimising inductor area and, simultaneously, maximising its quality factor, while maintaining a specified inductance value at a given operating frequency. As opposed...
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Simple Superstrate Antenna for Connectivity Improvement in Precision Farming Applications
PublicationIn this paper, a concept of a simple circularly polarized antenna with partially reflecting surface (PRS) has been adopted for precision farming applications. The investigation contains an analysis of the dependence of the antenna performance on the elements number in the PRS structure in X- and Ka-band frequencies. Especially meaningful parameters from point-to-point connectivity perspective are...
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Simulation of unsteady flow over floodplain using the diffusive wave equation and the modified finite element method
PublicationWe consider solution of 2D nonlinear diffusive wave equation in a domain temporarily covered by a layer of water. A modified finite element method with triangular elements and linear shape functions is used for spatial discretization. The proposed modification refers to the procedure of spatial integration and leads to a more general algorithm involving a weighting parameter. The standard finite element method and the finite difference...
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Simple empirical formula to estimate the main geomechanical parameters of preplaced aggregate concrete and conventional concrete
PublicationPreplaced aggregate concrete (PAC) or two-stage concrete is a specific type of concrete successfully employed in many projects including underwater concrete structures, massive concrete structures, structures made of reinforced concrete, and improvement of concrete structures. PAC is significantly different than the conventional concrete. In this type of concrete, aggregates are initially poured into the mold, the voids between...
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Shape memory thin films of Polyurethane: Does graphene content affect the recovery behavior of Polyurethane nanocomposites?
PublicationThin nanocomposite films of polyurethane have received remarkable attention due to their shape memory properties. As most of the reports focus on the beneficial aspects of the presence of nanofillers such as graphene nanoplatelets (GNPs) introduced into shape memory polymers, some research results reveal the opposite trend. The polyether/polyester-based polyurethane was synthesized through a condensation polymerization and the...
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GPR investigation of the strengthening system of a historic masonry tower
PublicationIn this paper the condition assessment of the strengthening system of a masonry tower was carried out by the GPR method. The study provided unique experimental data acquired during measurements of the reinforced concrete frame embedded in masonry walls. Conducted numerical and experimental investigations were focused on the phenomenon of the diffraction-refraction scattering of the electromagnetic energy. A hyperbola resulting...
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Application of commercial microwave links (CMLs) attenuation for quantitative estimation of precipitation
PublicationPrecipitation estimation models are typically sourced by rain gauges, weather radars and satellite observations. A relatively new technique of precipitation estimation relies on the network of Commercial Microwave Links (CMLs) employed for cellular communication networks: the rain-inducted attenuation in the links enables the precipitation estimation. In the paper, it is analysed to what extent the precipitation derived from CML...
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Magnetoelectric, spectroscopic, optical and elastic properties of Co-doped BaTiO3 ceramics
Publicationhe BaTiO3 perovskite is widely used in the electronic technology due to its dielectric, piezoelectric and ferroelectric properties and is a well-known base for obtaining a promising multifunctional material. In this paper we report the extensive studies on the Co-doped BaTiO3 ceramics for the wide range cobalt content. Full structural characterization of studied samples in a 20–450 K range was provided. The results of research...
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Cleaner energy for sustainable future using hybrid photovoltaics-thermoelectric generators system under non-static conditions using machine learning based control technique
PublicationIn addition to the load demand, the temperature difference between the hot and cold sides of the thermoelectric generator (TEG) module determines the output power for thermoelectric generator systems. Maximum power point tracking (MPPT) control is needed to track the optimal global power point as operating conditions change. The growing use of electricity and the decline in the use of fossil fuels have sparked interest in photovoltaic-TEG...
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Analiza wrażliwości tarczy z wykorzystaniem metody elementów skończonych
PublicationW pracy przedstawiono przykład zastosowania analizy wrażliwości tarczy modelowanej przy pomocy metody elementów skończonych. Podstawy teoretyczne oraz przykład numeryczny dotyczą wpływu różnicowania grubości całej tarczy oraz jej obszarów – jako zmiennej pro-jektowej – na przemieszczenie wybranego punktu – jako zmiennej stanu.
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Analiza doświadczalna wpływu długości zakotwienia pręta na zachowanie przyczepności w teście pull-out
PublicationArtykuł prezentuje badania przyczepności przeprowadzone przy użyciu testu pull-out. Eksperymenty miały na celu ocenę wpływu długości zakotwienia na przyczepność w tym teście. Z przeprowadzonej analizy wynika, że długość styku pręt-beton znacząco wpływa na zachowanie przyczepności. Określa ona typ zniszczenia połączenia, wpływa na rozkład i wartość naprężeń w pręcie oraz rzutuje na przebieg krzywej przyczepność-poślizg, która jest...
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Evaluation of the structures size in the liquid-gas flow by gamma-ray absorption
PublicationThe rapid development of tomography methods particularly electrical, X and gamma rays allows for a wide range of the information about flow structure. However, all of such methods are quite complicated. At the same time much simpler systems as the measuring system of gamma rays absorption, allows to obtain a all key flow information which describe the two-phase flow. In the article the results of analyzes of radiometric signal...
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Influence of local bush wear on water lubricated sliding bearing load carrying capacity
PublicationOne of main problems concerning water-lubricated bearings is their durability. There are known cases of bearings with life time measured in decades, and some, whose refurbishment was necessary just days after start-up. Obtaining stable fluid film friction plays key role in the durability of these bearings. Unfortunately, their load-carrying capacity is limited due to water's low-viscosity. The conducted experimental...
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Designing effective educational games - a case study of a project management game
PublicationThis paper addresses the issues of designing effective educational games. We aim at investigating how the cognitive, behavioral and emotional aspects of the games influence their educational effectiveness. The results were obtained with an observational user experience study extended with affect analysis carried out for a project management game GraPM. We analyzed the...
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The use of Response Surface Methodology for reliability estimation of composite engineering structures
PublicationStability loss is one of the key issues in the analysis of shells made of composite materials. This paper aims at finding the variation of the critical or limit value of the load resulting from geometric imperfections. An axially compressed 16-layer cylindrical panel model is considered. The imperfections of the panel are simulated as random fields. The parameters of these fields are used as the basic variables of the reliability...
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Exhaust gas temperature measurements in diagnostic examination of naval gas turbine engines. Part II. Unsteady processes
PublicationThe second part of the article presents the results of operating diagnostic tests of a two- and three-shaft engine with a separate power turbine during the start-up and acceleration of the rotor units. Attention was paid to key importance of the correctness of operation of the automatic engine load control system, the input for which, among other signals, is the rate of increase of the exhaust gas flow temperature. The article...
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Foundations of Grid Processing Architecture for the Comcute System
PublicationFundamental system algorithms and structures implemented in the Comcute system are described and analysed in detail. Layered architecture of the system model is highlighted. System tasks of the layers are elaborated, presented and described. Operational details of communication interfaces among layers are worked out and examined. The focus is put onto implemented system components with regard to their operability and efficiency....
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Intelligence Augmentation and Amplification: Approaches, Tools, and Case Studies
PublicationMost experts agree that truly intelligent artificial system is yet to be developed. The main issue that still remains a challenge is imposing trust and explainability into such systems. However, is full replication of human intelligence really desirable key aim in intelligence related technology and research? This is where the concept of augmented intelligence comes into play. It is an alternative conceptualization of artificial...
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Quantum randomness protected against detection loophole attacks
PublicationDevice and semi-device-independent private quantum randomness generators are crucial for applications requiring private randomness. However, they are vulnerable to detection inefficiency attacks and this limits severely their usage for practical purposes. Here, we present a method for protecting semi-device-independent private quantum randomness generators in prepare-and-measure scenarios against detection inefficiency attacks....
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Subcritical bifurcation of free elastic shell of biological cluster
PublicationIn this paper we will investigate symmetry-breaking bifurcation of equilibrium forms of biological cluster. A biological cluster is a two-dimensional analogue of a gas balloon. The cluster boundary is connected with its kernel by elastic links. The inside part is filled with compressed gas or fluid. Equilibrium forms of biological cluster can be found as solutions of a certain second order ordinary functional-differential equation...
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Improving the production planning and control process
PublicationFocusing the activities of a production business on the strategy based on quality entails orientation on meeting the expectations of the customers with respect to the product itself, and the terms of its delivery. The article notes the role of the production planning and control process in improving the quality of the business offer. It identifies the objectives set for the process from the perspective of meeting the expectations...
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On the Importance of Resilience Engineering for Networked Systems in a Changing World
PublicationResilience is featured increasingly often in the media, usually applied to society when faced, for example, with disasters such as flooding and the enormous challenges that the Covid-19 pandemic posed. There are now many resilience-related discussion groups worldwide, and some standards initiatives devoted in particular to city resilience. However, there is relatively little explicit interest in resilience engineering for communication...
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Modelowanie zmiennej krzywizny na długości toru zwrotnego rozjazdu
PublicationW pracy została przedstawiona analityczna metoda wyznaczania krzywizny toru zwrotnego rozjazdu kolejowego posiadającego na swojej długości odcinki zmiennej krzywizny. Taki rozjazd jest dedykowany w głównym stopniu kolejom dużych prędkości. Rozpatrzono dwa odrębne przypadki obejmujące liniowy przebieg krzywizny oraz przebieg nieliniowy, w postaci wielomianowej. Uzyskane rozwiązania problemu pozwalają na przyjmowanie dowolnych wartości...
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The influence of small amount of substances present in tissue on the optical spectrum of immunosuppressive drug
PublicationIn this paper, we describe how commonly present in tissue substances - sodium chloride and glucose - affect the optical spectrum of an immunosuppressive drug (Cyclaid® by Apotex). Prepared samples were investigated using the spectrophotometer in the spectrum range from 250 nm to 1100 nm. The maximum wavelength shift calculated on the basis of measurement results is not bigger than the measurement wavelength step. So, it can be...
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Electromagnetic Problems Requiring High-Precision Computations
PublicationAn overview of the applications of multiple-precision arithmetic in CEM was presented in this paper for the first time. Although double-precision floating-point arithmetic is sufficient for most scientific computations, there is an expanding body of electromagnetic problems requiring multiple-precision arithmetic. Software libraries facilitating these computations were described, and investigations requiring multiple-precision...
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Extendable Safety and Security Ontology
PublicationSecurity plays an increasingly important role in our everyday life, and research and users of computer systems point out that the need arises for a common, formalised model capable of integrating different solutions. In this paper we show that an ontology can be designed and created in a way that will make it suitable for interoperability and integration. A security and safety ontology and the methodology for creating a common...
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Numerical simulation of asphalt mixtures fracture using continuum models
PublicationThe paper considers numerical models of fracture processes of semi-circular asphalt mixture specimens subjected to three-point bending. Parameter calibration of the asphalt mixture constitutive models requires advanced, complex experimental test procedures. The highly non-homogeneous material is numerically modelled by a quasicontinuum model. The computational parameters are averaged data of the components, i.e. asphalt, aggregate...
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Mathematical analysis of a generalised p53-Mdm2 protein gene expression model
PublicationWe propose the generalisation of the p53-Mdm2 protein gene expression model introduced by Monk (2003). We investigate the stability of a unique positive steady state and formulate conditions which guarantee the occurrence of the Hopf bifurcation. We show that oscillatory behaviour can be caused not only by time lag in protein transcription process, but also can be present in the model without time delay. Moreover, we investigate...
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Estymacja napięcia niezrównoważenia w obwodzie pośredniczącym falownika trójpoziomowego NPC na podstawie analizy prądów wyjściowych
PublicationZaproponowano prostą i skuteczną metodę wyznaczania wartości napięcia niezrównoważenia w obwodzie pośredniczącym trójpoziomowego falownika NPC (ang. Neutral-Point-Clamped). Zastosowanie proponowanej metody nie wymaga dodatkowych czujników pomiarowych, a nakłady obliczeniowe na realizację algorytmu są niewielkie. Do wyznaczania napięcia niezrównoważenia wykorzystuje się informacje zawarte w mierzonych prądach wyjściowych falownika....
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Reliability assessment of truss towers using Monte Carlo Method, PEM and RSM
PublicationThe paper discusses reliability assessment of simple random truss structures using three different probabilistic methodologies: the Monte Carlo Method (MCM), the Point Estimate Method (PEM) and the Response Surface Method (RSM). A benchmark truss structure and a simplified full–size engineering tower are both analyzed. A set of ultimate load numerical calculations is performed and the results are taken as the basis of advanced...
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Rainscreen panels deformations mods
PublicationIn rainscreen panels designing simplified calculation models are used. For plate computation simply supported panels or panels with fixed edges are commonly used. Such approximations are subjected to large errors that lead to inefficient rainscreen panels design. In order to develop a method for determining the optimal geometry of the rainscreen panels, that would take into consideration the real stiffness of both continuous and...
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Molecular detection of Candida krusei
PublicationThe species identification of fungi belonging to genus Candida is an important issue as this genus becomes the emerging problem of nosocomial infections. As Candida krusei presents intrinsicresistance to the fluconazole that is the drug of the first choice in case of invasive candidiasis the PCR identifying the DNA of C. krusei was elaborated. The analytical sensitivity of the assay on spiked blood samples was estimated at 3-5...
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A case study of robust sliding mode control applied to inverted pendulum on a cart
PublicationA control problem of an inverted pendulum on a cart has been addressed in this paper. In particular, a synthesis of alternative sliding mode control for stabilisation of an inverted pendulum at an upper equilibrium point has been investigated. Hence, the feasibility of implementing the developed control system, taking into account primarily the friction of the cart against the gantry and the limited length of the gantry, in a real...
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Heuristic Method of Safe Manoeuvre Selection Based on Collision Threat Parameters Areas
PublicationThis paper is a continuation of papers dedicated to a radar-based CTPA (Collision Threat Parameters Area) display designed to support safe manoeuvre selection. The display visualizes all the ships in an encounter and presents situational overview from the own ship’s point of view. It calculates and displays information on unsafe or unrealistic own ship’s course & speed allowing a user to select a safe manoeuvre. So far only the...
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A novel sensor for measuring temperature profile during the thermoablation
PublicationAbstract — A novel approach for monitoring a temperature distribution inside a tissue during thermoablation is presented in the paper. A thermal profile is measured using a set of serially connected thermistors each bypassed by a capacitor. This technique allows a two-wire and simultaneous multi- point measurements using a multi-frequency measurement of electrical impedance. It is...
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Measurement Stand and Methodology for Research of the Off-Body and Body-to-Body Radio Channels in WBANs with Different Diversity Schemes
PublicationThe concept of an experimental test bed for system loss and channel impulse response measurements for off-body and body-to-body radio channels in wireless body area networks (WBANs) is fully described. The possible measurement scenarios that may occur in investigation of off-body and body-to-body channels are classified and described in detail. Additionally, an evaluation is provided of the standard and expanded uncertainties of...
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3D PCB package for GaN inverter leg with low EMC feature
PublicationThis paper presents the adaptation of a 3D integration concept previously used with vertical devices to lateral GaN devices. This 3D integration allows to reduce loop inductance, to ensure more symmetrical design with especially limited Common Mode emission, thanks to a low middle point stray capacitance. This reduction has been achieved by both working on the power layout and including a specific shield between the devices and...
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Homoclinic and Heteroclinic Orbits for a Class of Singular Planar Newtonian Systems
PublicationThe study of existence and multiplicity of solutions of differential equations possessing a variational nature is a problem of great meaning since most of them derives from mechanics and physics. In particular, this relates to Hamiltonian systems including Newtonian ones. During the past thirty years there has been a great deal of progress in the use of variational methods to find periodic, homoclinic and heteroclinic solutions...
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Existence and uniqueness of solutions for single-population McKendrick-von Foerster models with renewal
PublicationWe study a McKendrick-von Foerster type equation with renewal. This model is represented by a single equation which describes one species which produces young individuals. The renewal condition is linear but takes into account some history of the population. This model addresses nonlocal interactions between individuals structured by age. The vast majority of size-structured models are also treatable. Our model generalizes a number...
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Critical Remarks on Landauer’s principle of erasure– dissipation: Including notes on Maxwell demons and Szilard engines
PublicationWe briefly address Landauer’s Principle and some related issues in thermal demons. We show that an error-free Turing computer works in the zero-entropy limit, which proves Landauer’s derivation incorrect. To have a physical logic gate, memory or information-engine, a few essential components necessary for the operation of these devices are often neglected, such as various aspects of control, damping and the fluctuation–dissipation...
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Model Order Reduction for Problems With Dispersive Surface Boundary Conditions
PublicationThis letter proposes a new scheme for reduced-order finite-element modeling of electromagnetic structures with nonlinear, dispersive surface boundary conditions, which optimally exploits the numerically stable and efficient MOR framework for second-order systems provided by SAPOR method. The presented results of numerical experiments for an example of a waveguide filter demonstrate the superior accuracy of the resulting reduced models...
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Identification of dynamic parameters in the context of diagnostics of steel tank with different level of liquid.
PublicationThe paper presents an experimental study to identify the dynamic parameters of a water-filled tank model. The experimental modal analysis approach involving the excitation at one point of the structure and acquisition of vibra tions at selected points distri buted over the tank surface allowed to determine the resonance frequencies, mode shapes and damping ratios. The main aim of the research was to examine the influence of...
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Optimization of the System for Determining the Volume of Tissue Needed for Breast Reconstruction
PublicationThis article presents techniques for reconstructing surfaces and volume calculations using a point cloud generated from 3D imaging. The main objective of this article was to optimize the voxel size for the most accurate representation of the surface of the female breast. We experimented with different methods for determining volume using images from the Intel D435i camera. In addition, we designed application and measurement station...
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3D-Breast System for Determining the Volume of Tissue Needed for Breast Reconstruction
Publication3D imaging systems can be used to effectively determine breast volumes for surgical applications. This article presents methods for surface reconstruction and volume determination based on the point cloud created by 3D imaging. Such a system would be used to accurately estimate breast volume in patients classified for breast reconstruction surgery at plastic surgery centers. To develop such a system, various methods of determining...
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Combined partial denitrification/anammox process for nitrogen removal in wastewater treatment
PublicationRecently, the combined partial denitrification and anammox (PD/anammox) has received special attention as a viable alternative for N removal using organic matter present in municipal wastewater. In comparison with conventional nitrification-denitrification, PD/anammox provides enormous opportunities to achieve sustainable wastewater treatment due to the lack of dissolved oxygen (DO) demand, a smaller amount of organic carbon (C)...