Filters
total: 1809
filtered: 1325
-
Catalog
- Publications 1325 available results
- Journals 19 available results
- Conferences 1 available results
- Publishing Houses 2 available results
- People 111 available results
- Projects 28 available results
- e-Learning Courses 48 available results
- Events 15 available results
- Open Research Data 260 available results
Chosen catalog filters
displaying 1000 best results Help
Search results for: CENTER CHANNEL EXTRACTION
-
Study of the Performance of DSSS UAC System Depending on the System Bandwidth and the Spreading Sequence
PublicationA signal transmitted in an Underwater Acoustic Communication (UAC) system operating in a shallow-water channel suffers from strong time dispersion due to multipath propagation. This causes the Inter-Symbol Interference (ISI) observed in the received signal, which significantly limits the communication system’s reliability and transmission rate. In such propagation conditions, the Direct-Sequence Spread Spectrum (DSSS) method is...
-
Design and experimental investigations of a cylindrical microjet heat exchanger for waste heat recovery systems
PublicationCompact heat exchangers have more and more applications in many areas, including the HVAC, food and petrochemical industry. This paper describes the development of heat exchanger technology for waste heat recovery (WHR) from a range of processes. Case-study testing shows that the proposed heat exchanger can successfully enhance heat transfer and recover waste heat in a range of applications making them economically, environmentally and...
-
Zastosowanie metod eksploracji danych do analizy odpowiedzi czujników gazu
PublicationZagadnienia poruszane w niniejszej rozprawie dotyczą zastosowania metod eksploracji danych do analizy odpowiedzi czujników gazu, umożliwiających poprawną identyfikację składu mieszaniny gazowej w elektronicznych systemach rozpoznawania gazu. Elektroniczne systemy rozpoznawania gazu to urządzenia wykorzystujące czujniki gazu oraz odpowiednio dobrane metody analizy danych pomiarowych, zdolne do określenia składu mierzonej mieszaniny...
-
Progress in development of molecularly imprinted polymers as sorbents for sample preparation
PublicationSample preparation has been one of the most often investigated steps in analytical procedures.These investigations are focused on problems such as isolation of analytes from the sample matrix, matrix implification, analyte enrichment to the level above the detection limit of the instrumentation used, and the removal of interfering species to improve the final determination. Techniques based on solid (adsorption) and pseudo liquid...
-
Determination of parent and methylated polycyclic aromatic hydrocarbons in water samples by dispersive liquid–liquid microextraction–two dimensional gas chromatography–time-of-flight mass spectrometry
PublicationPolycyclic aromatic hydrocarbons (PAHs) are contaminants frequently found in environmental waters. Owing to their toxic effects, it is important to develop analytical methodologies that allow their fast and reliable determination. Dispersive liquid–liquid microextraction (DLLME) allows a quick extraction of analytes with little organic solvent consumption. The best results regarding sample preparation are obtained when 40 mL of...
-
Comparison of different techniques for extracting Polychlorinated Biphenyls from bottom sediment samples using Isotope Dilution Mass Spectrometry
PublicationIn this work, problems that may occur during determination of trace levels of polychlorinated biphenyls in sediment samples are described. The main error sources are connected with extraction of analytes prior to final determination. During model studies, polychlorinated biphenyls have been extracted from sediment reference material (METRANAL 2) with the use of different solvents (dichloromethane, hexane, and toluene); the process...
-
The use of Kamienna głowa cabbage species for phytoextraction of zinc and cadmium from the soil
PublicationAlthough traditional technologies for cleaning contaminated soils have proven to be efficient, they are usually expensive, labor intensive, and in the case of soil, they produce severe disturbance. Most recently, the use of plants in metal extraction (phytoremediation) has appeared as a promising alternative in the removal of heavy metal excess from soil. Phytoremediation uses of plant for pollutant stabilization, extraction, degradation,...
-
Deep eutectic solvent (DES) with silver nanoparticles (Ag-NPs) based assay for analysis of lead (II) in edible oils
PublicationThis paper presents an application of silver nanoparticles impregnated by Deep Eutectic Solvents (DES) as ultrasonication aided microextraction system for lead (II) determination in edible oils. The paper presents a systematic optimization of method parameters and examples of its application for analysis of real samples. Maximum recovery for lead (II) extraction was obtained for choline chloride and phenol with a 1:2 molar ratio....
-
Discovery of Stylistic Patterns in Business Process Textual Descriptions: IT Ticket Case
PublicationGrowing IT complexity and related problems, which are reflected in IT tickets,create a need for new qualitative approaches. The goal isto automate the extraction of main topics described in tickets in order to provide high quality support for the IT process workers and enablea smooth service delivery to the end user. Present paper proposes a method of knowledge extraction in a form of stylistic patterns in business...
-
Alternative Methods of Preparation of Soluble Keratin from Chicken Feathers
PublicationHuge amount of keratinous waste, especially birds’ feathers, demands more value-added application instead of dumping. The present work reports the results of experiments aimed at preparing soluble keratin useful for novel bioproduct formation. The effect of thermo-chemical treatments with various reducing agents, i.e. 2-mercaptoethanol, dithiothreitol, sodium m-bisulphite, and sodium bisulphite, as well as sodium hydroxide, on...
-
On Accuracy Modeling of Gas Turbine Cycles by the In-house COM-GAS Code
PublicationIn this paper, a comparison of accuracy modeling of gas turbine cycles between the basic (classical) model and the in-house COM-GAS code has been presented. The basic model uses a semi-perfect gas and well known projecting assumption. On the other hand, the computational flow mechanics (CFM) basis on a real gas by using thermodynamic tables. The thermodynamic analysis of thermal cycles, simply gas cycle GT8C and gas turbine cycle...
-
Aplikacja demonstrująca działanie kodów fontannowych
PublicationIstotną cechą kodów fontannowych jest możliwość odtwarzania nadawanych danych niezależnie od jakości kanału. Wynika to z tego, że kody te nie mają z góry założonej zawartości informacyjnej, a kolejne symbole nadmiarowe są generowane, dopóki jest taka potrzeba. Jest to szczególnie przydatne w transmisjach broadcastowych, bo każdy z odbiorców może zdekodować dane tak wcześnie, na ile pozwala jakość łącza. Aby przybliżyć funkcjonowanie...
-
DETEKCJA FAL UDERZENIOWYCH W UKŁADACH ŁOPATKOWYCH CZĘŚCI NISKOPRĘŻNYCH TURBIN PAROWYCH
PublicationW artykule przedstawiono wyniki numerycznych symulacji okołodźwiękowego przepływu pary przez ostatnie stopnie części niskoprężnej turbiny o mocy 50 MW. Celem przeprowadzonych symulacji była detekcja oraz lokalizacja fali uderzeniowej, występującej dla przyjętej geometrii układu łopatkowego. Przeanalizowano również wpływ zmiany wartości ciśnienia na wlocie do rozpatrywanych stopni turbiny na maksymalną wartość...
-
Multicriteria decision analysis in ranking of analytical procedures for aldrin determination in water
PublicationThe study presents the possibility of multi-criteria decision analysis (MCDA) application when choosing analytical procedures with low environmental impact. A type of MCDA, Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE), was chosen as versatile tool that meets all the analytical chemists – decision makers requirements. Twenty five analytical procedures for aldrin determination in water samples (as...
-
Optimization of capillary isotachophoretic method for determination of major macroelements in blue honeysuckle berries (Lonicera caerulea L.) and related products
PublicationA reliable and repeatable isotachophoretic method for the simultaneous determination of K+, Na+, Ca2+, Mg2+ and ammonium in berries of different blue honeysuckle cultivars was developed. The usefulness of the complex-forming equilibria in determining the cations mentioned above was studied. The addition of 7.5 mM 18-crown-6 and 2 mM α-hydroxyisobutyric acid to sulfuric acid enhanced the separation capacity of the leading electrolyte....
-
Development and validation of a GC–MS/MS method for the determination of 11 amphetamines and 34 synthetic cathinones in whole blood
PublicationPurpose Psychoactive compounds that contain a phenylethylamine structure (such as amphetamine-type stimulants and synthetic cathinones) are one of the major classes of stimulants on the recreational drug market. Approximately 670 new psychoactive substances (NPS) are monitored only in Europe; however, new psychoactive compounds are being developed for illicit trade each year. In this context, the development of new analytical procedures...
-
An idea of an approach to self-testing of mixed signal systems based on a quadratic function stimulation
PublicationA new approach to self-testing of the analog parts of mixed-signal electronic systems controlled by microcontrollers equipped with an ADC and a DAC is presented. It is based on a BIST and a new fault diagnosis method. A novelty is the use of the DAC as a component of the BIST, allowing to generate a stimulating signal with a quadratic function shape. It contributes to a better extraction of information about the state of the circuit...
-
Phosphinoborenium cations stabilized by N-heterocyclic carbenes: synthesis, structure, and reactivity
PublicationPhosphinoborenium cations stabilized by N-heterocyclic carbenes (NHCs) were synthesized via the reaction of bromo(phosphino)boranes with NHCs. Their structures were investigated by heteronuclear magnetic resonance spectroscopy, X-ray diffraction, and density functional theory calculations. They possess a planar trigonal boron center directly bonded with the pyramidal phosphanyl group (PR2) and can be treated as cationic phosphinoboranes....
-
Data Acquisition in a Manoeuver Auto-negotiation System
PublicationTypical approach to collision avoidance systems with artificial intelligence support is that such systems assume a central communication and management point (such as e.g. VTS station), usually located on shore. This approach is, however, not applicable in case of an open water encounter. Thus, recently a new approach towards collision avoidance has been proposed, assuming that all ships in the encounter, either restricted or open...
-
Decoherence-free communication over multiaccess quantum channels
PublicationIn this paper we consider decoherence-free communication over multiple access and k-user quantum channels. First, we concentrate on a hermitian unitary noise model U for a two-access bi-unitary channel and show that in this case a decoherence-free code exists if the space of Schmidt matrices of an eigensubspace of U exhibits certain properties of decomposability. Then, we show that our technique is also applicable for generic random unitary...
-
Influence of nodes with positive eccentricity on load-carrying capasity of truss' top chords in trusses made of welded cold-formed members.
PublicationIn order to establish the influence of eccentric crossing of truss members on the load-carrying capacity of the folded chord of a hat-section truss, a research model was created and preliminary numerical analysis of the truss was performed with the use of Marc Mentat programme. Distorial instability of crossheads caused by deviation of loose (unmounted) channel section web’s bends was observed. Due to the slenderness of the section’s...
-
Generalized adaptive notch smoothing revisited
PublicationThe problem of identification of quasi-periodically varying dynamic systems is considered. This problem can be solved using generalized adaptive notch filtering (GANF) algorithms. It is shown that the accuracy of parameter estimates can be significantly increased if the results obtained from GANF are further processed using a cascade of appropriately designed filters. The resulting generalized adaptive notch smoothing (GANS) algorithm...
-
An Approach to Mean Path Loss Model Estimation for Off-Body Channels
PublicationThis paper presents an approach to estimation of the mean path loss model parameters in off-body Body Area Networks channels. In this approach, the path loss exponent is constrained to a value obtained for the line-of-sight (LoS) propagation in the co-polarised channel, considering a generalised static scenario. The comparison of the goodness of fit between the proposed approach and other approaches, for a set of measurements obtained...
-
Green Analytical Chemistry Approaches in Sample Preparation
PublicationThis chapter presents environmentally friendly solutions for sample preparation. Attention is focused on extraction techniques and the minimization of organic solvent consumption, as the large quantitiesused in analytical laboratories are a pressing environmental problem. Solventless sample preparation techniques, alternative solvents, mediated extractions are discussed. The principle of each technique isbriefly described, together...
-
Niebezpieczeństwo ukryte w żywności-aminy biogenne. Cz. II. Metody oznaczania i wyzwania.
PublicationZe względu na aktywność biologiczną amin biogennych ich oznaczanie zarówno jakościowe, jak i ilościowe w żywności ma istotne znaczenie w celu zapewnienia ochrony zdrowia i życia ludzkiego. Obecnie do monitoringu amin biogennych w żywności najczęściej wykorzystuje się: wysokosprawną chromatografię cieczową (HPLC), chromatografię cienkowarstwową (TLC) oraz absorpcyjną spektrofotometrię cząsteczkową. Są to jednak techniki czasochłonne,...
-
Multivariate Assessment of Procedures for Molecularly Imprinted Polymer Synthesis for Pesticides Determination in Environmental and Agricultural Samples
PublicationIn the case of quantitative and qualitative analysis of pesticides in environmental and food samples, it is required to perform a sample pre-treatment process. It allows to minimalize the impact of interferences on the final results, as well as increase the recovery rate. Nowadays, apart from routinely employed sample preparation techniques such as solid-phase extraction (SPE) or solid-phase microextraction (SPME), the application...
-
Sorbents modified by deep eutectic solvents in microextraction techniques
PublicationIn recent years, considerable attention has been directed towards the employment of green solvents, specifically deep eutectic solvents (DES), in liquid phase microextraction techniques. However, comprehensive and organized knowledge regarding the modification of sorbent surface structures with DES remains limited. Therefore, this paper reviews the application of DES in modifying and improving the properties of sorbents for microextraction...
-
Investigation of vortex assisted magnetic deep eutectic solvent based dispersive liquid–liquid microextraction for separation and determination of vanadium from water and food matrices: Multivariate analysis
PublicationA new and simple vortex assisted magnetic deep eutectic solvent dispersive liquid–liquid microextraction procedure (VA-MDES-DLLME) was developed for the determination of vanadium (V) in food and water samples by flame atomic absorption spectrometry (FAAS). In the extraction medium, a bis(acetylpivalylmethane) ethylenediimine (H2APM2en) was used for the complexation of V(V) in sample solution at pH 6. The VA-MDES-DLLME was optimized...
-
Comparison of Two Methods for the Determination of Selected Pesticides in Honey and Honeybee Samples
PublicationDeveloped and validated analytical methods for the determination of a wide spectrum of pesticide residues in honey and honeybee samples after the modification of QuEChERS extraction in combination with gas chromatography–tandem quadrupole mass spectrometry (GC-MS/MS) and liquid chromatography–tandem quadrupole mass spectrometry (LC-MS/MS) were discussed and compared. The developed methods were evaluated regarding the utilized equipment...
-
Chemometric Assessment and Best-Fit Function Modelling of the Toxic Potential of Selected Food Packaging Extracts
PublicationFood packaging materials constitute an ever more threatening environmental pollutant. This study examined options to specifically assess the ecotoxicity of packaged wastes, such as cans, subjected to various experimental treatments (in terms of extraction media, time of exposure, and temperature) that imitate several basic conditions of the process of food production. The extracts were studied for their ecotoxicity with bioluminescent...
-
Hazard Control in Industrial Environments: A Knowledge-Vision-Based Approach
PublicationThis paper proposes the integration of image processing techniques (such as image segmentation, feature extraction and selection) and a knowledge representation approach in a framework for the development of an automatic system able to identify, in real time, unsafe activities in industrial environments. In this framework, the visual information (feature extraction) acquired from video-camera images and other context based gathered...
-
Thermal Imaging in Wound Healing Diagnostics
PublicationResults of a project searching for objective, quantitative evaluation of postoperative wound healing in cardiosurgery are presented. We propose simple thermal models of the healing processes after cardiosurgery interventions as objective descriptors allowing classification of patients for extraction and following recovery at home or for prolonged treatment in a hospital. Classification of healing as the normal process or as a process...
-
Oxidation step in the preparation of benzocamalexin: The crystallographic evidence
PublicationThe study of oxidation step in the preparation of benzocamalexin by the α-amidoalkylation–oxidation sequence revealed the formation of perchloro-1,2-phenylene dibenzoate as the product of transformation of tetrachloro- 1,2-benzoquinone applied as the oxidant. The structures of benzocamalexin and perchloro-1,2-phenylene dibenzoate were confirmed by X-ray diffraction analysis. The extraction step in the final isolation of benzocamalexin...
-
Comparison of Methods for Real and Imaginary Motion Classification from EEG Signals
PublicationA method for feature extraction and results of classification of EEG signals obtained from performed and imagined motion are presented. A set of 615 features was obtained to serve for the recognition of type and laterality of motion using 8 different classifications approaches. A comparison of achieved classifiers accuracy is presented in the paper, and then conclusions and discussion are provided. Among applied algorithms the...
-
Rule-Based Model for Selecting Integration Technologies for Smart Cities Systems
PublicationThe aim of this article is to present the stages of development for an information technology integration model for the design of systems for smart cities. The Introduction explains the need for integration technologies and presents a model for selecting integration technologies and the conditions for its use in designing smart cities systems. Then two verification stages of the presented model are discussed. In the first stage,...
-
Hybrid battery based on arylated carbon nanotubes and laccase
PublicationSingle-walled carbon nanotubes (SWCNT) were covalently modified with anthracene and anthraquinone and used for the construction of cathodes for biocatalytic reduction of dioxygen. The nanotubes with aromatic groups casted onto the electrode increased the working surface of the electrode and enabled efficient direct electron transfer (DET) between the enzyme and the electrode. The aryl groups enter the hydrophobic pocket of the...
-
Rotating rod and ball
PublicationWe consider a mechanical system consisting of an infinite rod (a straight line) and a ball (a massless point) on the plane. The rod rotates uniformly around one of its points. The ball is reflected elastically when colliding with the rod and moves freely between consecutive hits. A sliding motion along the rod is also allowed. We prove the existence and uniqueness of the motion with a given position and velocity at a certain time...
-
Analysis of the Application of Horizontal Directional Drilling
PublicationConstruction works are often considered to be very intrusive for the environment. Project designers assume deep excavations, or a complete replacement of the ground within the investment, which sometimes changes the initial conditions drastically. The problem started to appear in places, where the terrain is complicated and the excavation is burdensome. Some of state authorities...
-
Quantum key distribution based on private states: Unconditional security over untrusted channels with zero quantum capacity
PublicationIn this paper, we prove unconditional security for a quantum key distribution (QKD) protocol based on distilling pbits (twisted ebits) from an arbitrary untrusted state that is claimed to contain distillable key. Our main result is that we can verify security using only public communication-via parameter estimation of the given untrusted state. The technique applies even to bound-entangled states, thus extending QKD to the regime...
-
Experimental investigations on pressure drop during the condensation in flow of HFE7000 in vertical minichannel
PublicationIn the work presented in the paper authors focused attention on the issues of flow resistance and pressure drop during condensation in the flow. The case of the descending flow through a cylindrical single-channel of 2.3 mm inner diameter was carefully analyzed. In the course of investigations a new working fluid HFE 7000 has been scrutinised which has a strongly differing properties in comparison to the other fluids that are commonly...
-
Balance errors in numerical solutions of shallow water equations
PublicationThe analysis of the conservative properties of the shallow water equations is presented in the paper. The work focuses on the consistency of numerical solution of these equations with the conservation laws of mass and momentum. The investigations involve two different conservative forms which are solved by an implicit box scheme. The theoretical analysis supported by numerical experiments is carried out for rectangular channel...
-
Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublicationThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
-
LSTM-based method for LOS/NLOS identification in an indoor environment
PublicationDue to the multipath propagation, harsh indoor environment significantly impacts transmitted signals which may adversely affect the quality of the radiocommunication services, with focus on the real-time ones. This negative effect may be significantly reduced (e.g. resources management and allocation) or compensated (e.g. correction of position estimation in radiolocalisation) by the LOS/NLOS identification algorithm. This paper...
-
Deep Learning-Based LOS and NLOS Identification in Wireless Body Area Networks
PublicationIn this article, the usage of deep learning (DL) in ultra-wideband (UWB) Wireless Body Area Networks (WBANs) is presented. The developed approach, using channel impulse response, allows higher efficiency in identifying the direct visibility conditions between nodes in off-body communication with comparison to the methods described in the literature. The effectiveness of the proposed deep feedforward neural network was checked on...
-
Technical solutions and benefits of introducing rain gardens – Gdańsk case study
PublicationNowadays, Nature-Based Solutions (NBSs) are developing as innovative multifunctional tools to maximize urban ecosystem services such as storm water preservation, reduction of runoff and flood protection, groundwater pollution prevention, biodiversity enhancement, and microclimate control. Gdańsk is one of the first Polish cities to widely introduce rain gardens (one example of an NBS) in different areas such as parks, city center,...
-
Processing of Satellite Data in the Cloud
PublicationThe dynamic development of digital technologies, especially those dedicated to devices generating large data streams, such as all kinds of measurement equipment (temperature and humidity sensors, cameras, radio-telescopes and satellites – Internet of Things) enables more in-depth analysis of the surrounding reality, including better understanding of various natural phenomenon, starting from atomic level reactions, through macroscopic...
-
Distinctive facades of commercial buildings and the quality of public space,
PublicationMutual relations between the retail center and public spaces of the city are varied. They depend on the type and size of the commercial structure. Other ones are for multifunctional shopping centers and other for high streets. In megastores and shopping malls the essential for their functioning is their interior and entrance, which is sometimes the only place of interpenetration of the commercial structure with the surrounding...
-
Towards Resource Theory of Coherence in Distributed Scenarios
PublicationThe search for a simple description of fundamental physical processes is an important part of quantum theory. One example for such an abstraction can be found in the distance lab paradigm: if two separated parties are connected via a classical channel, it is notoriously difficult to characterize all possible operations these parties can perform. This class of operations is widely known as local operations and classical communication....
-
Verification of the method of reconstructing convective velocity fields on the basis of temperature fields in vertical, differential and equally heated, open and closed channels
PublicationThis paper describes a method of reconstructing velocity fields, i.e. a numerical reconstruction procedure (NRP) that involves the numerical processing of experimentally measured temperature distributions in free convection heat transfer. The NRP consists in solving only the continuity and Navier–Stokes equations with an additional source term. This term is proportional to a known temperature (e.g. from a thermal imaging camera)...
-
Determination of volatile organic compounds in water samples using membrane-solid phase microextraction (M-SPME) (headspace version)
PublicationThe results of a study on the use of membrane-solid phase microextraction (M-SPME) for sampling volatile organic compounds (VOCs) from the headspace above the liquid medium are presented. The sampled VOCs were subsequently quantified by gas chromatography (GC). Two systems were compared in this study, i.e. a novel two-phase sorption system (M-SPME), and a commercial fibre. Headspace sampling using SPME was optimized with respect...