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Search results for: MARKOV OPERATORS
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The study of acoustic climate of the Southern Baltic
PublicationThis paper presents the statistical characteristics of seawater properties, which are necessary for predicting the propagation of acoustic waves in selected areas of the Baltic Sea. The statistics were elaborated based on long-term measurements of vertical distributions of sound speed, temperature, and salinity, and the nonlinearity parameter B/A. Nonlinear properties of the environment are considered, in connection...
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Simplified Map-based Selection of Optimal Spindle Speeds When Milling Complex Structures
PublicationIn the paper a method for selecting optimal spindle speeds for complex structures during milling operations is presented. It is based on the selection of the spindle speed in accordance with a simple equation resulting from the minimisation of vibration energy, which leads to the minimisation of the work of cut-ting forces presented in previous elaborations by the authors [1]. Optimal spindle speeds are obtained for many points...
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Estimators of covariance matrices in Msplit(q) estimation
PublicationThis paper proposes methods for the determination of covariance matrices of Msplit(q) estimators. The solutions presented here allow Msplit(q) estimation to be supplemented by the operations from the domain of accuracy analysis (especially that concerning estimators of parameters). Theoretical forms of covariance matrices of Msplit(q) estimators were established using the empirical influence functions and the equivalent covariance...
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Zaprojektowanie, wykonanie i sterowanie panelem słonecznym
PublicationOdnawialne źródła energii stają się coraz bardziej popularne. Rynek fotowoltaiki w ostatnich latach znacznie powiększył swój udział w zaspokajaniu zwiększonego zapotrzebowania na energię wszystkich gałęzi przemysłu oraz gospodarek państw. Obecny etap rozwoju technologicznego dąży do maksymalizowania sprawności przetwarzania energii słonecznej na energię elektryczną. Prężnie rozwijająca się automatyzacja pozwala na budowę układów,...
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Positron scattering on molecular hydrogen: Analysis of experimental and theoretical uncertainties
PublicationExperiments performed in recent years on positron scattering from molecular hydrogen indicated a rise of the total cross section in the limit of zero energy, but essentially disagree on the amplitude of this rise. Mitroy and collaborators [J.-Y. Zhang et al., Phys. Rev. Lett. 103, 223202 (2009)] predicted a scattering length somewhat different from values deduced experimentally. Using a Markov chain Monte Carlo modified effective...
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A comparative study of English viseme recognition methods and algorithms
PublicationAn elementary visual unit – the viseme is concerned in the paper in the context of preparing the feature vector as a main visual input component of Audio-Visual Speech Recognition systems. The aim of the presented research is a review of various approaches to the problem, the implementation of algorithms proposed in the literature and a comparative research on their effectiveness. In the course of the study an optimal feature vector construction...
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A comparative study of English viseme recognition methods and algorithm
PublicationAn elementary visual unit – the viseme is concerned in the paper in the context of preparing the feature vector as a main visual input component of Audio-Visual Speech Recognition systems. The aim of the presented research is a review of various approaches to the problem, the implementation of algorithms proposed in the literature and a comparative research on their effectiveness. In the course of the study an optimal feature vector...
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Anterior subcutaneous transposition and simple decompression of the ulnar nerve at the elbow – the postoperative improvement in DASH score, VAS score and sonographic findings
PublicationIntroduction. Although a lot of studies have described long- term outcomes after surgical treatment of cubital tunnel syndrome, and the usefulness of sonography in diagnosing of this disorder, few studies have evaluated patients self-reporting outcomes or sonographic findings after surgery. Aim. We assessed patients self-reporting instruments and sonographic findings in patients with the cubital tunnel syndrome before and after...
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Dependence of Housing Real Estate Prices on Inflation as One of the Most Important Factors: Poland’s Case
PublicationThe study aimed to examine the impact of inflation on the real estate market using Polish panel data for the last 13 years. It is based on a panel model, where price changes of one square meter of housing are determined as a function in changes of inflation, the central bank's base rate, dwellings built, as well as new mortgage loans. The quarterly dynamics of the average price of 1 square meter of housing in...
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Employment of University Graduates in the Era of Digitalization and Artificial Intelligence: Challenges and Prospects
PublicationDigital technologies are profoundly reshaping the labor market, causing structural shifts in the economy and altering the nature of work. These changes have significant implications for youth employment, exacerbating the issue of unemployment. This paper delves into the importance of graduate employment in contemporary society, with a particular focus on the influence of digital technologies and Artificial Intelligence. The authors...
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Thermoplastic elastomer filaments and their application In 3D printig
PublicationThe paper provides an overview on the materials used in the 3D printing technology (the Polish and foreign market) with a particular focus on flexible filaments and their possible application in the industry. There are described the techniques of 3D printing and modern filaments available on the market. There is observed the increase of interest in the production of products from filaments based on thermoplastic elastomers (TPE),...
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Design analysis of Tesla micro-turbine operating on a low-boiling medium
PublicationThis paper presents results of the design analysis of a Tesla bladeless turbine intended for a co-generating micro-power plantof heat capacity 20 kW, which operates in an organic Rankine cycle on a low-boiling medium. Numerical calculations of flowin several Tesla turbine models were performed for a range of design parameters. Results of investigations exhibit interestingfeatures in the distribution of flow parameters within the...
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Possibility of Fault Detection in Sensorless Electric Drives
PublicationThe work presents a fault detection method for an induction motor drive system with inverter output filter. This approach make use of a load torque state observer, which complete structure is presented along with the used control structure. Moreover, the demonstrated drive system operates without rotor speed measurement in conjunction with the multiscalar control. The verification of the demonstrated idea was performed on an experimental...
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Acoustic Processor of the MCM Sonar
PublicationThis paper presents the concept of an acoustic processor of the mine countermeasure sonar. Developed at the Department of Marine Electronics Systems, Gdansk University of Technology, the acoustic processor is an element of the MG-89, a modernised underwater acoustic station. The focus of the article is on the modules of the processor. They are responsible for sampling analogue signals and implementing the algorithms controlling...
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Solving Boundary Value Problems for Second Order Singularly Perturbed Delay Differential Equations by ε-Approximate Fixed-Point Method
PublicationIn this paper, the boundary value problem for second order singularly perturbed delay differential equation is reduced to a fixed-point problem v = Av with a properly chosen (generally nonlinear) operator A. The unknown fixed-point v is approximated by cubic spline vh defined by its values vi = vh(ti) at grid points ti, i = 0, 1, ... ,N. The necessary for construction the cubic spline and missing the first derivatives at the boundary...
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Hazardous material-related propagation of the effects of train accidents in the subgrade
PublicationA large part of the transport of hazardous materials is carried out by rail. Therefore, the security of these transports is becoming increasingly important. Every catastrophe involving dangerous materials has a negative impact on the participants of the incident and the surrounding environment, because its range is generally not local. It follows that in the event of a catastrophe, its effects should be minimized and remediation...
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Theory versus experiment for vacuum Rabi oscillations in lossy cavities
PublicationThe 1996 experiment by Brune et al. [Phys. Rev. Lett. 76, 1800 (1996)] on vacuum Rabi oscillation is analyzed by means of alternative models of atom-reservoir interaction. Agreement with experimental Rabi oscillation data can be obtained if one defines jump operators in the dressed-state basis and takes into account thermal fluctuations between dressed states belonging to the same manifold. Such low-frequency transitions could...
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Hidden Tensor Structures
PublicationAny single system whose space of states is given by a separable Hilbert space is automatically equipped with infinitely many hidden tensor-like structures. This includes all quantum mechanical systems as well as classical field theories and classical signal analysis. Accordingly, systems as simple as a single one-dimensional harmonic oscillator, an infinite potential well, or a classical finite-amplitude signal of finite duration...
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New Performance Indices for Power System Stabilizers
PublicationThe subject of the article is issues related to innovative indices for power system stabilizers (PSSs). These new indices will be able to quickly show which PSS (among many other PSSs) is not working properly and that advanced optimization and simulation methods should be used to improve the PSS settings. The authors note the fact that the acceptance requirements for PSSs are different in various power systems. Moreover, the authors...
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Wireless Link Selection Methods for Maritime Communication Access Networks—A Deep Learning Approach
PublicationIn recent years, we have been witnessing a growing interest in the subject of communication at sea. One of the promising solutions to enable widespread access to data transmission capabilities in coastal waters is the possibility of employing an on-shore wireless access infrastructure. However, such an infrastructure is a heterogeneous one, managed by many independent operators and utilizing a number of different communication...
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Travel agents and destination management organizations: eLearning as a strategy to train tourism trade partners.
PublicationThis article offers an overview of the existing online courses run by national destination management organizations (DMOs) in order to better equip travel agents and tour operators in the sales activities of the tourism destinations. These online courses represent one of the B2B offers by DMOs and an interesting opportunity for travel agents, who are trying to find their identity and competitive advantage within the context of...
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Analysis of an Energy Management System of a Small Plant Connected to the Rural Power System
PublicationThis paper presents the analysis of an energy management system (EMS) implemented to fulfill the requirements of a microgrid (MG) power supply owned by a small industrial company and connected to the rural power system. The main goal of this system is to ensure connection with the existing rural power system in terms of energy exchange, as well as to perform islanding mode operation of the microgrid based on the energy demand of...
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Quaternion encryption methods for multimedia transmission, a survey of existing approaches
PublicationIn this paper we review quaternion encryption methods for multimedia transmission. We explain their weak and strong properties as well as suggest possible modifications. Our main focus is an algorithm QFC presented in paper by Dzwonkowski et al. (2015). All encryption methods, presented in this paper, use special properties of quaternions to perform rotations of data sequences in 3D space. Each method uses a common key generation...
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Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublicationThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
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Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublicationThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
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Complexity analysis of the Pawlak’s flowgraph extension for re-identification in multi-camera surveillance system
PublicationThe idea of Pawlak’s flowgraph turned out to be a useful and convenient container for a knowledge of objects’ behaviour and movements within the area observed with a multi-camera surveillance system. Utilization of the flowgraph for modelling behaviour admittedly requires certain extensions and enhancements, but it allows for combining many rules into a one data structure and for obtaining parameters describing how objects tend...
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Polyarmonic model of synchronous generator for analysis of autonomous power generation systems
PublicationAbstract: This paper presents the polyharmonic modelling of synchronous generator (SG) in machine variables. The simple geometry and windings physical layout has been used for inductance calculations of a salient-pole SG. The main advantage of this model is the ease of describing an autonomous power generation system (APGS) in terms of its topology and thus providing effective analysis at the static and dynamic states, both for...
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Modelowanie bezpieczeństwa maszyn i instalacji krytycznych
PublicationW rozdziale zostały omówione metody modelowania bezpieczeństwa instalacji krytycznych. W złożonym obiekcie podwyższonego ryzyka wyróżniono warstwy procesu technologicznego, systemów monitorowania i sterowania, alarmów krytycznych i interwencji operatorów, warstwy systemów automatyki zabezpieczeniowej SIS, zabezpieczeń inżynieryjnych, oraz warstwy przeciwdziałań wewnętrznych i zewnętrznych. Zwrócono uwagę na rolę jaką pełnią systemy...
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Initial Considerations
PublicationChemical processes have made use of a wide number of volatile organic solvents due to their efficiency in countless unit operations. The increasing knowledge on the environmental, health, and safety hazards associated to their use has significantly contributed to the search for greener alternatives. The primary purpose of this book is to provide an overview of alternative solvents with reduced issues that have successfully replaced...
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Nauka w świecie cyfrowym okiem młodego inżyniera - nawigacja mobilna w miastach
PublicationDynamiczny rozwój technologii ICT i miniaturyzacja komponentów elektronicznych doprowadziły do sytuacji, w której znaczna część światowego społeczeństwa korzysta z urządzeń mobilnych. Dzięki powszechnemu dostępowi do smartfonów każdy użytkownik może w prosty sposób sprawdzić swoje położenie, niezależnie od tego, gdzie w danej chwili się znajduje. Ponadto sami operatorzy sieci komórkowych oraz dostawcy szeregu serwisów korzystają...
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UWB-Based Indoor Navigation in a Flexible Manufacturing System Using a Custom Quadrotor UAV
PublicationA novel solution for indoor navigation of a transportation drone in flexible manufacturing is presented in this paper. To address the challenges of accurate and robust drone navigation in occluded environments, an ultra-wideband (UWB) navigation system has been integrated with a commercially available open source control platform. The system offers high accuracy (± 20 mm), low power consumption, resistance to electronic interference,...
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Identification of Emotions Based on Human Facial Expressions Using a Color-Space Approach
PublicationHCI technology improves human-computer interaction. Such communication can be carried out with the use of emotions that are visible on the human face since birth. In this paper the Emotion system for detecting and recognizing facial expressions, developed in the MSc work, is presented. The system recognizes emotion from webcam video in real time. It is based on color segmentation and morphological operations. The system uses a...
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Komercyjne moduły superkondensatorów. Wybrane zagadnienia aplikacyjne
PublicationDynamiczny rozwój technologii i konstrukcji superkondensatorów, stymulowany głównie potrzebami przemysłu motoryzacyjnego pozwala na stwierdzenie, e staj si one coraz bardziej realną alternatywą dla tradycyjnych akumulatorów. Za ich stosowaniem przemawia: możliwość szybkiego ładowania i rozładowania, wielokrotnie wyższa trwałość, bezobsługowość eksploatacji oraz zastosowanie do ich budowy materiałów, które nie zagrażają środowisku...
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Zdalne modelowanie i walidacja projektów hybrydowych instalacji fotowoltaicznych wspomaganych ogniwami paliwowymi
PublicationW artykule zaprezentowano opracowany i wykonany w Instytucie Technologii Elektronowej wielofunkcyjny demonstrator systemu, który pozwala na zdalne modelowanie, monitorowanie i walidację projektów hybrydowych instalacji fotowoltaicznych wspomaganych ogniwami paliwowymi oraz prowadzenie różnorodnych eksperymentów i badań naukowych. Dostępność do systemu za pośrednictwem sieci Ethernet lub GSM pozwala również na zdalne prowadzenie...
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Zdalne modelowanie i walidacja projektów hybrydowych instalacji fotowoltaicznych wspomaganych ogniwami paliwowymi
PublicationW artykule zaprezentowano opracowany i wykonany demonstrator systemu, który umożliwia modelowanie, monitorowanie i walidację projektów hybrydowych instalacji fotowoltaicznych wspomaganych ogniwami paliwowymi, a także prowadzenie eksperymentów i badań naukowych. Dostępność systemu za pośrednictwem sieci Ethernet lub GSM pozwala na zdalne prowadzenie prac wszędzie tam, gdzie zapewniony jest dostęp do sieci internetowej. Zastosowanie...
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Komercyjne moduły superkondensatorów. Wybrane zagadnienia aplikacyjne
PublicationDynamiczny rozwój technologii i konstrukcji superkondensatorów, stymulowany głównie potrzebami przemysłu motoryzacyjnego pozwala na stwierdzenie, e staj si one coraz bardziej realną alternatywą dla tradycyjnych akumulatorów. Za ich stosowaniem przemawia: możliwość szybkiego ładowania i rozładowania, wielokrotnie wyższa trwałość, bezobsługowość eksploatacji oraz zastosowanie do ich budowy materiałów, które nie zagrażają środowisku...
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Molecular and chemical monitoring of growth and Ochratoxin A biosynthesis of P. verrucosum in wheat stored at different moisture conditions
PublicationDoświadczenie polegało na obserwacji wzrostu P. verrucosum na ziarnach pszenicy, składowanej w różnych warunkach (wilgotność, temperatura) oraz zdolności do produkcji Ochratoksyny A (OTA) przez tę pleśń. Wzrost mierzony był w jednostkach tworzących kolonie (cfu colony forming units). Biosynteza OTA kontrolowana była przy pomocy HPLC, a ekspresja genu otapksPV syntetazy OTA mierzona w czasie przy pomocy odwrotnej transkryptazy...
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Modeling of effect of plastic deformation on Barkhausen noise and magnetoacoustic emission in iron with 2% silicon
PublicationW modelowaniu zaadaptowano model Alessandro-Beatrice-Bertotti-Montorsi dla opisu ruchu granic nie-180 stopniowych oraz model Jiles-Atherton dla opisu wpływu plastycznej deformacji na natężenie efektu Barkhausena oraz emisji magnetoakustcznej.
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Tripped at the Finishing Line: The Åland Islands Internet Voting Project
PublicationThe Åland Islands spent years preparing an internet voting system, to be implemented for the first time in October 2019 for Parliamentary Elections. Despite this, the project was canceled the evening before the expected release date. In this paper, we explore the causes of this failure using a two-pronged approach including Information System failure perspectives and the approach to e-voting Mirabilis, focusing on organizational...
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Application of dispersive liquid-liquid microextraction and gas chromatography with mass spectrometry for the determination of oxygenated volatile organic compounds in effluents from the production of petroleum bitumen
PublicationWepresent a new procedure for the determination of oxygenated volatile organic compounds in samples of postoxidative effluents from the production of petroleum bitumens using dispersive liquid–liquid microextraction and gas chromatography with mass spectrometry. The eight extraction parameters were optimized for 43 oxygenated volatile organic compounds. The detection limits obtained ranged from 0.07 to 0.82 g/mL for most of the...
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Application of dynamic headspace and gas chromatography coupled to mass spectrometry (DHS-GC-MS) for the determination of oxygenated volatile organic compounds in refinery effluents
PublicationThe paper presents a new procedure for the determination of oxygenated volatile organic compounds (O-VOCs) in postoxidative effluents from the production of petroleum asphalt using dynamic headspace coupled to gas chromatography-mass spectrometry in the selected ion monitoring (SIM) mode (DHSGC-MS). Among the GC capillary columns tested, a polar SLB-IL111 column with the ionic liquid stationary phase was found to be superior due...
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Separation of Volatile Oxygen-containing Organic Compounds by Gas Chromatography - selectivity comparison of different polarity stationary phases
PublicationThis paper present a results of the separation of 36 reference compounds belonging to the group of Volatile Oxygen-Containing Organic Compounds (OVOCs) using capillary gas chromatography with flame ionization detector (GC-FID) and three stationary phases of different polarity. A selectivity has been studied regarding to OVOCs and n -alkanes. The most useful for the separation of the group OVOCs is a polar ionic liquid stationary...
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Usefulness of separation techniques for identification and determination of Oxygenated Volatile Organic Compounds used in process analytics of water and wastewater
PublicationW pracy przedstawiono przegląd i porównanie metodyk identyfikacji i oznaczania Lotnych Związków Tlenoorganicznych (LZT). Porównano metodyki klasyczne umożliwiające oznaczanie wybranej grupy związków chemicznych należących do LZT lub dokonywanie oznaczeń sumarycznej zawartości z metodykiami wykorzystującymi techniki rozdzielania. Lotne związki tlenoorganicze, do których zaliczane są aldehydy, alkohole, ketony, estry, etery oraz...
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Application of ionic liquids in chromatographic techniques
PublicationCiecze jonowe (ang. Ionic Liquids, ILs) z uwagi na swoje unikalne właściwości fizyko – chemiczne oraz możliwość prostej modyfikacji budowy, w znacznym stopniu przyczyniły się do rozwoju technik rozdzielania. W chromatografii gazowej fazy stacjonarne w postaci cieczy jonowych stanowią istotne uzupełnienie istniejących faz stacjonarnych na bazie polisiloksanów i glikolu polietylenowego. Ze względu na wysoką stabilność termiczną...
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Zastosowanie chromatografii gazowej do rozdzielania i oznaczania lotnych związków azoto – organicznych (LZN) w próbkach wody i ścieków.
PublicationW pracy dokonano przeglądu i porównania metod opartych na chromatografii gazowej do oznaczania lotnych związków azoto-organicznych (LZN) w próbkach wody i ścieków. Przedstawione zostały metodyki analityczne wykorzystujące zarówno detektory selektywne tj. detektor azotowo-fosforowy (NPD), detektor powierzchniowej jonizacji (SID), detektor chemiluminescencyjny azotu (CLND), detektor wychwytu elektronów (ECD) jak i detektorów uniwersalnych...
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Chemometryczne podejście do optymalizacji dyspersyjnej mikroekstrakcji w układzie ciecz-ciecz (DLLME), jako metody przygotowania próbek do rozdzielania i oznaczania krezoli w ściekach rafineryjnych
PublicationW pracy przedstawiono procedurę optymalizacji dyspersyjnej mikroekstrakcji w układzie ciecz-ciecz (DLLME), z zastosowaniem frakcyjnych planów czynnikowych tj. planu Placketta-Burman’a oraz centralnego planu kompozycyjnego. Zdefiniowano parametry mające istotny wpływ na efektywność ekstrakcji krezoli i dla nich przeprowadzono procedurę optymalizacyjną, w wyniku której wyznaczono wartości optymalne parametrów w tym pH 6 oraz objętość...
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Zastosowanie chromatografii gazowej do oceny stopnia degradacji LZO w ściekach przemysłowych po procesach oczyszczania
PublicationW pracy przedstawiono przykład zastosowania metodyki DLLME-GC-MS w trybie SCAN, w połączeniu z modelem MCR-ALS, do identyfikacji lotnych związków organicznych (LZO) obecnych w próbkach surowych ścieków z produkcji asfaltów naftowych, a także oceny stopnia ich degradacji po zastosowaniu różnych metod oczyszczania chemicznego. Wykorzystanie modelu chemometrycznego do dekonwolucji sygnałów chromatograficznych umożliwiło identyfikację...
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Method for the simultaneous determination of monoaromatic and polycyclic aromatic hydrocarbons in industrial effluents using dispersive liquid-liquid microextraction with GC-MS
PublicationWe present a new method for simultaneous determination of 22 monoaromatic and polycyclic aromatic hydrocarbons in postoxidative effluents from the production of petroleum bitumen using dispersive liquid-liquid microextraction coupled to gas chromatography and mass spectrometry. The eight extraction parameters including the type and volume of extraction and disperser solvent, pH, salting out effect, extraction and centrifugation...
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Hydrophobic deep eutectic solvents as “green” extraction media for polycyclic aromatic hydrocarbons in aqueous samples
PublicationThe paper presents novel nonionic and hydrophobic deep eutectic solvents which were synthesized from natural compounds, i.e., thymol, ±camphor, decanoic and 10-undecylenic acids. Fundamental physicochemical properties of the synthesized deep eutectic solvents were determined, followed by their application as extractants in ultrasound-assisted dispersive liquid-liquid microextraction to isolate and enrich polycyclic aromatic hydrocarbons...
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Pilot scale degradation study of 16 selected volatile organic compounds by hydroxyl and sulfate radical based advanced oxidation processes
PublicationThe studies of effective technologies for complete degradation of the volatile organic compounds (VOCs), are very important due to the high biotoxicity of the VOCs which makes the biological technologies ineffective. It also increases the risk of VOCs emission instead of their treatment when using open air biological technologies. In the present study, different types of Advanced Oxidation Processes (AOPs) were investigated for...