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Wyniki wyszukiwania dla: nanofluids free convection
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Accuracy of marine gravimetric measurements in terms of geodetic coordinates of land reference benchmark
PublikacjaThe article presents how the values of (3D) coordinates of land reference points affect the results of gravimetric measurements made from the ship in sea areas. These measurements are the basis for 3D maritime inertial navigation, improving ships' operational safety. The campaign verifying the network absolute point coordinates used as a reference point for relative marine gravity measurements was described. The obtained values...
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A Web-GIS tool for diagnosing spatial orientation of young adults: design and evaluation of Geo-Survey
PublikacjaSpatial orientation is the effectiveness with which one is able to assess the mutual location of objects relative to a point of reference or a system of coordinates. Traditionally, this ability has been evaluated through field navigation tests, which do not take into account the prevailing influence of free online maps and virtual walks on a person’s interpretation of space. In this context, this study presents a Web-GIS tool designed...
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Peroxymonosulfate-assisted photocatalytic degradation of artificial sweeteners in water
PublikacjaIn the present study, peroxymonosulfate (PMS) activation was proposed for efficient photocatalytic degradation of aspartame, acesulfame, saccharin, and cyclamate - artificial sweeteners frequently present in wastewaters and surface waters worldwide. The TiO2 nanosheets with exposed {0 0 1} facets were synthesised using the fluorine-free lyophilisation technique as a green concept for the synthesis and used for the photodegradation...
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Constructive Controllability for Incompressible Vector Fields
PublikacjaWe give a constructive proof of a global controllability result for an autonomous system of ODEs guided by bounded locally Lipschitz and divergence free (i.e. incompressible) vector field, when the phase space is the whole Euclidean space and the vector field satisfies so-called vanishing mean drift condition. For the case when the ODE is defined over some smooth compact connected Riemannian manifold, we significantly strengthen...
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THE APPLICATION OF THE MECHANOCHEMICAL SYNTHESIS FOR THE PREPARATION OF ADVANCED CERAMICS BASED ON BARIUM TITANATE
PublikacjaIn the present study, the lead-free BaTi1-xZrxO3 (for x = 0, 0.05 and 0.15) ceramics were prepared by High-Energy Ball Milling and heat treatments. The performed X-ray, SEM and EDS measurements confirmed high purity, good quality and the expected quantitative composition of the obtained samples. The study of dielectric properties was performed by means of broadband dielectric spectroscopy at the frequency ranging from 0.1 Hz to...
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Virtual immersive environments
PublikacjaYet 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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Researching Digital Society: Using Data-Mining to Identify Relevant Themes from an Open Access Journal
PublikacjaOpen Access scholarly literature is scientific output free from economic barriers and copyright restrictions. Using a case study approach, data mining methods and qualitative analysis, the scholarly output and the meta-data of the Open Access eJournal of e-Democracy and Open Government during the time interval 2009–2020 was analysed. Our study was able to identify the most prominent research topics (defined as thematic clusters)...
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Molecular Umbrella as A Nanocarrier for Antifungals
PublikacjaA molecular umbrella composed of two O‐sulfated cholic acid residues was applied for the construction of conjugates with cispentacin, containing a “trimethyl lock” (TML) or o‐dithiobenzylcarbamoyl moiety as a cleavable linker. Three out of five conjugates demonstrated antifungal in vitro activity against C. albicans and C. glabrata but not against C. krusei, with MIC90 values in the 0.22–0.99 mM range and were not hemolytic. Antifungal...
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Researching Digital Society: Using Data-Mining to Identify Relevant Themes from an Open Access Journal
PublikacjaOpen Access scholarly literature is scientific output free from economic barriers and copyright restrictions. Using a case study approach, data mining methods and qualitative analysis, the scholarly output and the meta-data of the Open Access eJournal of e-Democracy and Open Government during the time interval 2009–2020 was analysed. Our study was able to identify the most prominent research topics (defined as thematic clusters)...
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INFLUENCE OF THE HULL SHAPE ON THE ENERGY DEMAND OF A SMALL INLAND VESSEL WITH HYBRID PROPULSION
PublikacjaRecently, there has been a significant development of ecological propulsion systems, which is in line with the general trend of environmentally friendly “green shipping”. The main aim is to build a safe, low-energy passenger ship with a highly efficient, emission-free propulsion system. This can be achieved in a variety of ways. The article presents the main problems encountered by designers and constructors already at the stage...
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Implementation of high-precision computation capabilities into the open-source dynamic simulation framework YADE
PublikacjaThis paper deals with the implementation of arbitrary precision calculations into the open-source discrete element framework YADE published under the GPL-2+ free software license. This new capability paves the way for the simulation framework to be used in many new fields such as quantum mechanics. The implementation details and associated gains in the accuracy of the results are discussed. Besides the "standard" double (64 bits)...
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Decrease in Photovoltaic Module Efficiency Due to Deposition of Pollutants
PublikacjaThe deposition of pollutants on the surface of photovoltaic (PV) modules reduce the efficiency that can be achieved in given climatic conditions. This results in the loss of energy yield obtained from the solar installation. A number of factors determine the scale of this problem. The first of these is the amount of impurities deposited, the associated amount of precipitation, and the speed and direction of the wind. A second aspect...
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Modeling the Structure, Dynamics, and Transformations of Proteins with the UNRES Force Field
PublikacjaThe physics-based united-residue (UNRES) model of proteins ( www.unres.pl ) has been designed to carry out large-scale simulations of protein folding. The force field has been derived and parameterized based on the principles of statistical-mechanics, which makes it independent of structural databases and applicable to treat nonstandard situations such as, proteins that contain D-amino-acid residues. Powered by Langevin dynamics...
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PROJEKT STANDARDÓW DOSTĘPNOŚCI DLA OSÓB ZE SZCZEGÓLNYMI POTRZEBAMI DO TRANSPORTOWYCH WĘZŁÓW PRZESIADKOWYCH
PublikacjaW artykule opisano projekt standardów dostępności zintegrowanych węzłów przesiadkowych, które zawierają spójne dla wszystkich elementów ZWP z uwzględnieniem potrzeb i wymagań osób ze szczególnymi potrzebami zasady projektowania, budowy i utrzymania oraz minimalne parametry kluczowych dla samodzielnej realizacji podróży przez osoby ze szczególnymi potrzebami rozwiązań i udogodnień. Przedstawione standardy zawierają zasady i wymagania...
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ZASTOSOWANIE APLIKACJI INTERNETOWEJ W OCENIE JAKOŚCI DOPASOWANIA APARATÓW SŁUCHOWYCH
PublikacjaW pracy opisano zastosowanie aplikacji internetowej do oceny jakości dopasowania aparatów słuchowych. Metoda oceny polega na badaniu ankietowym, uzupełnionym testem rozumienia słów jednosylabowych w polu swobodnym. Opisywana aplikacja internetowa pozwala na przeprowadzenie badania z dowolnego komputera z dostępem do sieci. Dzięki implementacji metody w postaci aplikacji internetowej, można w systematyczny i uporządkowany sposób...
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The effect of boron concentration on the electrical, morphological and optical properties of boron-doped nanocrystalline diamond sheets: Tuning the diamond-on-graphene vertical junction
PublikacjaIn this paper, the effect of boron doping on the electrical, morphological and structural properties of free-standing nanocrystalline diamond sheets (thickness ~ 1 μm) was investigated. For this purpose, we used diamond films delaminated from a mirror-polished tantalum substrate following a microwave plasma-assisted chemical vapor deposition process, each grown with a different [B]/[C] ratio (up to 20,000 ppm) in the gas phase....
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Determination of isoprostanes in exhaled breath condensate samples by liquid chromatography coupled with tandem mass spectrometry
PublikacjaOxidative stress (OS) is a state of imbalance between continuously generating reactive oxygen species (ROS) during normal cell metabolism and mechanism of detoxifying oxygen radicals through a network of antioxidative enzymes. Isoprostanes are prostaglandin -like substances that are produced in vivo primarily by free radical-induced peroxidation of arachidonic acid. The measurement of isoprostanes in biological fluids and/or tissue...
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The Examination of the Upper Layers of the Seabed by the Means of the Acoustic Methods
PublikacjaPropagation of acoustic waves in the sea, in particular in shallow sea, depends on several factors. The basic of them are source power and frequency of acoustic waves, spatial distribution inhomogeneous medium in which acoustic wave propagates, and distributions of speed of sound and density of seawater. The coastal conditions, which limit water medium from above (free surface of the sea) and from bottom (the seabed), are no less...
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Determination of volatile organic compounds using solventless sample preparation techniques and gas chromatography
PublikacjaIn this paper the latest advances in the determination of volatile organic compounds using solvent-free extraction techniques in the sample preparation step are presented. A paper is focus mainly on one of the most popular sample preparation technique: solid-phase microextraction technique (SPME) combined with different detection systems and its applications to sampling of VOCs from the samples with different matrices. This paper...
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Chemical composition of lipids isolated from selected organs and tissues of the raccoon dog (Nyctereutes procyonoides)
PublikacjaOur paper presents a qualitative analysis of particular lipid classes (phospholipids, triacylglycerols, cholesterol, free fatty acids) isolated from the tissues of raccoon dogs harvested in northeastern Poland. In all examined tissues (except for the liver) the dominant group of lipids were triacylglycerols. The amounts of lipids representing the other classes depended on the kind of tissue from which the fat was isolated. The...
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The Boltzmann sequence-structure channel
PublikacjaWe rigorously study a channel that maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein statistics. This channel, which we also call the Boltzmann sequence-structure channel, is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. In our previous work, we verified experimentally that the channel capacity has a phase transition for...
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Synthesis and polymerisation techniques of molecularly imprinted polymers
PublikacjaMolecularly Imprinted Polymers (MIPs) are materials that has been processed using the molecular imprinting technique which permit to obtain well-defined three-dimensional cavities, with affinity to a template molecule, in the polymer matrix. Technology involves three strategies, i.e., covalent, non-covalent and semi-covalent approach, but the most popular is non-covalent approach. The most important components for the synthesis...
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Recycling of raw materials, silicon wafers and complete solar cells from photovoltaic modules
PublikacjaPhotovoltaic modules (PVs) are an attractive way of generating electricity in reliable and maintenance-free systems with the use of solar energy. The average lifetime of photovoltaic modules is 25 to 30 years. To offset the negative impact of photovoltaic modules on the environment, it is necessary to introduce a long-term strategy that includes a complete lifecycle of all system components from the production phase through installation...
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Impact of Low Switching-to-Fundamental Frequency Ratio on Predictive Current Control of PMSM: A simulation study
PublikacjaPredictive current control algorithms for permanent magnet synchronous (PMSM) drives rely on an assumption that within short intervals motor currents can be approximated with linear functions. This approximation may result either from discretizing the motor model or from simplifications applied to the continuous-time model. As the linear current approximation has been recognized as inaccurate in case when the drive operates with...
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Influence of Diosmin Treatment on the Level of Oxidative Stress Markers in Patients with Chronic Venous Insufficiency
PublikacjaOxidative stress plays an important role in the pathophysiology of many human disorders, while antioxidants prevent the development of various adverse symptoms. Diosmin is a natural flavonoid applied in vascular system disorders, especially in chronic venous insufficiency (CVI), and it plays a significant part in the alleviation of CVI symptoms. Due to antioxidant activity, it also has the ability to scavenge the oxygen free radicals...
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Theoretical Model of Acoustic Wave Propagation in Shallow Water
PublikacjaThe work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “ deformed”...
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Comparative study of a combined heat and power plant retrofitted by CO2 capture during the combustion of syngas from sewage sludge gasification versus zero-emission combustion of hydrogen produced using renewables
PublikacjaWith ecological requirements aimed at limiting the production of CO2, it is necessary to produce all, or most of the energy from RES. During the transformation process, ecological and highly efficient combustion power plants will be needed. The classic cycle of combined heat and power (CCGT) with green improvements will continue to be one of the most suitable technologies for this task. This article presents the modernization of...
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Synthesis of Phosphonated Carbon Nanotubes: New Insight into Carbon Nanotubes Functionalization
PublikacjaCarbon nanotubes were successfully functionalized for the first time in a free radical phosphonylation reaction. Three synthetic protocols were proposed. Carbon nanotubes and diethylphosphite reacted in the presence of known radical initiator, such as azobisisobutyronitrile, single electron oxidant—Mn(OAc)3, or under UV radiation. The functionalized material was fully characterized by means of spectroscopic methods, together with...
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Decoupled Kalman filter based identification of time-varying FIR systems
PublikacjaWhen system parameters vary at a fast rate, identification schemes based on model-free local estimation approaches do not yield satisfactory results. In cases like this, more sophisticated parameter tracking procedures must be used, based on explicit models of parameter variation (often referred to as hypermodels), either deterministic or stochastic. Kalman filter trackers, which belong to the second category, are seldom used in...
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Thermodynamic Studies of Interactions between Sertraline Hydrochloride and Randomly Methylated β-Cyclodextrin Molecules Supported by Circular Dichroism Spectroscopy and Molecular Docking Results
PublikacjaThe interaction between sertraline hydrochloride (SRT) and randomly methylated β-cyclodextrin (RM β CD) molecules have been investigated at 298.15 K under atmospheric pressure. The method used—Isothermal Titration Calorimetry (ITC) enabled to determine values of the thermodynamic functions like the enthalpy (DH), the entropy (DS) and the Gibbs free energy (DG) of binding for the examined system. Moreover, the stoichiometry coefficient...
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Quest for the Molecular Basis of Improved Selective Toxicity of All-Trans Isomers of Aromatic Heptaene Macrolide Antifungal Antibiotics
PublikacjaThree aromatic heptaene macrolide antifungal antibiotics, Candicidin D, Partricin A (Gedamycin) and Partricin B (Vacidin) were subjected to controlled cis-trans to all trans photochemical isomerization. The obtained all-trans isomers demonstrated substantially improved in vitro selective toxicity in the Candida albicans cells: human erythrocytes model. This effect was mainly due to the diminished hemotoxicity. The molecular modeling...
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The mechanical properties and bactericidal degradation effectiveness of tannic acid-based thin films for wound care
PublikacjaThe surface area is the most important aspect when considering the interactions between a material and the surrounding environment. Chitosan (CTS) and tannic acid (TA) were previously successfully tested by us to obtain thin films to serve as wound dressings or food packaging materials. However, surface properties as well as the antimicrobial activity of the material were not considered. They are important if the material is likely...
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Optimization of Wireless Networks for Resilience to Adverse Weather Conditions
PublikacjaIn this chapter, we consider how adverse weather conditions such as rain or fog affect the performance of wireless networks, and how to optimize these networks so as to make them robust to these conditions. We first show how to analyze the weather conditions in order to make them useful for network optimization modelling. Using an example realistic network, we show how to optimize two types of wireless networks: free-space optical...
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Dynamics of Chains as a Tool to Study Thermomechanical Properties of Proteins.
PublikacjaPolymer dynamics can be formulated on different levels of detail. One approach eliminates microscopic degrees of freedom and a polymer molecule is represented by a simplified structure—a chain. In the simplest case monomers of ideal chain have fixed length, and their orientation is independent of the orientations and positions of neighbouring monomers. This is reason that two monomers can co-exist at the same place. Ideal chain...
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Grafting and reactive extrusion technologies for compatibilization of ground tyre rubber composites: Compounding, properties, and applications
PublikacjaChemical modification of ground tyre rubber (GTR) to compatibilize it with the matrix is a well-known approach. Based on our recent review of the surface etching methods used in GTR modification, the purpose of the current work is to take a deeper look into more advanced methods such as grafting and reactive extrusion. While grafting is more efficient in achieving compatibility, however, it usually involves multi-step synthesis...
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Determination of selected parameters/ analytes in surface water samples collected in the surroundings of the capital of Spitsbergen (Longyearbyen)
PublikacjaPolar regions are extremely sensitive to pollution such as harmful gases, particles or toxic substances which affect the Arctic climate and ecosystems. Spitsbergen, as well as all Arctic region, because of its geographically distant location and lack of industry sector, should be free of chemical pollution. Despite this, many pollutants could be found in the Polar environment, for example in freshwaters. Their occurrence is related...
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Evaluation of RTKLIB's Positioning Accuracy Using low-cost GNSS Receiver and ASG-EUPOS
PublikacjaThe paper focuses on a comparison of different positioning methods provided by free and open source software (FOSS) package called RTKLIB. The RTKLIB supports real‐time and post‐processed positioning. The most important modes of operation tested by the authors are Kinematic, Static, Fixed and Precise Point Positioning (PPP). The data for evaluation were obtained from low‐cost Global Navigation Satellite System (GNSS) receiver....
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An updated method identifying collision-prone locations for ships. A case study for oil tankers navigating in the Gulf of Finland
PublikacjaTo ensure the risk level associated with continuously increasing maritime traffic through particularly sensitive sea areas remains at acceptable level, a periodic risk assessment needs to be carried out by the relevant authorities. As a part of such assessment, allowing for proactive countermeasures to mitigate risk, the frequency of accidents is estimated along with the assessment of geographical locations where the accidents...
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Study of Cloud Water Samples Collected over Northern Poland
PublikacjaThe paper gives the results of the first studies on the chemistry of cloud water collected during 3 mo (Aug.–Oct. 2010) in the free atmosphere over the area to the south of the Tri-City (Gdansk-Sopot-Gdynia) conurbation on the Gulf of Gdansk, Poland. Taken from cumulus, stratus, and stratocumulus clouds by means of an aircraft-mounted collector, the water samples were analyzed for the following contaminants: anions (chlorides,...
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Specific Binding of Cholesterol to the Amyloid Precursor Protein: Structure of the Complex and Driving Forces Characterized in Molecular Detail
PublikacjaC99 is the C-terminal membrane-bound fragment of the amyloid precursor protein that is cleaved by γ-secretase to release Aβ peptides, the hallmark of Alzheimer’s disease (AD). Specific interactions of C99 with cholesterol have been proposed to underlie the recognized role of cholesterol in promoting amyloidogenesis. By using molecular dynamics simulations, we studied cholesterol binding to C99 in a lipid bilayer. We determined...
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FURTHER REMARKS ON THE SURFACE VIS IMPRESSA CAUSED BY A FLUID-SOLID CONTACT
PublikacjaIt is well-known that, nano-mechanics should take into account not only physical phenomena occuring within the bulk but, first of all, the physical phenomena appropriate for a surface of two materials contact. The huge volume density of internal surfaces as well countours lines located within the nanomaterial results in our interest in, apart from classical form of mass, momentum and entropy transport, those modes of transportation...
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Interactions of fish gelatin and chitosan in uncrosslinked and crosslinked with EDC films: FT-IR study
PublikacjaFilms based on fish gelatin, chitosan and blend of fish gelatin and chitosan before and after cross-linking with EDC have been characterized by FT-IR spectroscopy. The FT-IR spectrum of fish gelatin film showed the characteristic amide I, amide II and amide III bands, and the FT-IR spectrum of chitosan film confirmed that the polymer was only a partially deacetylated product, and included CH3-C=O and NH2 groups, the latter both...
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Synthesis of amides under microwave irradiation
PublikacjaAmides belong to the most important carboxylic acid derivatives. They are constituents of natural compounds like peptides and proteins. They found applications in many branches of science and industry, especially in pharmaceutical and polymer science. Conventional procedures for amide preparation involve reaction between amine and carboxylic acid or their more active derivatives such as acid chlorides, acid anhydrides or esters....
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Surface Plasmon-Coupled Emission of Rhodamine 110 Aggregates in a Silica Nanolayer
PublikacjaFirst analysis of strong directional surface plasmon-coupled emission(SPCE) of ground-state formed intermolecular aggregates of Rhodamine 110 (R110) insilica nanofilms deposited on silver nanolayers is reported. Until now, the processes ofenergy transport and its trapping due to aggregate formation have not been studied in the presence of SPCE. A new approach to multicomponent systems with weakly and strongly fluorescent centers...
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Application and optimization of headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography - flame-ionization detector (GC-FID) to determine products of the petroleum industry in aqueous samples
PublikacjaA simple and solvent-free analytical method has been optimized for the determination of hydrocarbons (C6 - C20) from products of the petroleum industry in aqueous samples. Extraction and analysis was carried out using headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled with flame-ionization detector (GC-FID). A ZB-5 capillary column (30 m × 0.25 mm inner diameter, 0.25 µm film thickness) was used for...
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Automated Detection of Sleep Apnea and Hypopnea Events Based on Robust Airflow Envelope Tracking in the Presence of Breathing Artifacts. - [IEEE JOURNAL OF BIOMEDICAL AND HEALTH INFORMATICS]
PublikacjaThe paper presents a new approach to detection of apnea/hypopnea events, in the presence of artifacts and breathing irregularities, from a single channel airflow record. The proposed algorithm, based on a robust envelope detector , identifies segments of signal affected by a high amplitude mo d- ulation corresponding to apnea/hypopnea events. It is show n that a robust airflow envelope - free of breathing artifacts - improves effectiveness...
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Cure kinetics of epoxy/MWCNTs nanocomposites: Isothermal calorimetric and rheological analyses
PublikacjaA combinatorial route has been applied in cure kinetics study of epoxy nanocomposites containing multi-walled carbon nanotubes (MWCNTs) based on differential scanning calorimetry and rheokinetic analyses under isothermal conditions. Pristine and amine-modified MWCNTs bearing primary and secondary amines were used at very low concentrations (0.1 and 0.3 wt.% based on epoxy weight). Model-free and model-fitting methods were applied...
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Nonlinear planar modeling of massive taut strings travelled by a force-driven point-mass
PublikacjaThe planar response of horizontal massive taut strings, travelled by a heavy point-mass, either driven by an assigned force, or moving with an assigned law, is studied. A kinematically exact model is derived for the free boundary problem via a variational approach, accounting for the singularity in the slope of the deflected string. Reactive forces exchanged between the point-mass and the string are taken into account via Lagrange...
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Debonding Size Estimation in Reinforced Concrete Beams Using Guided Wave-Based Method
PublikacjaThe following paper presents the results of the theoretical and experimental analysis of the influence of debonding size on guided wave propagation in reinforced concrete beams. The main aim of the paper is a development of a novel, baseline-free method for determining the total area of debonding between steel rebar embedded in a concrete cover on the basis of the average wave velocity or the time of flight. The correctness of...
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Investigation of stability and limit load of a truss overhead opened bridge
PublikacjaThe paper presents selected methods of determining stability and limit load of a truss top chord in opened bridges. These methods include linear buckling and non-linear static analysis based on the finite element method and algorithms based on design code procedures. The described methods were tested on an example of a steel footbridge situated in Straszyn. The results of stability analysis are compared. The results of geometrical...