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Search results for: RADIOWAVE PROPAGATION
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NOBLE METAL MODIFIED TiO2 FOR PHOTOCATALYTIC AIR PURIFICATION
PublicationTiO2 was surface modified with silver, gold, palladium and platinum ion clusters to improve its photocatalytic activity. The effect of metal content, the kind of dopant used during preparation procedure on the photoactivity were investigated. in toluene removal which was used as a model volatile organic compound. Toluene, at the concentration of about 100 ppm, was irradiated over noble metal modified TiO2 using light-emitting diodes...
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Quantum dots in gas sensing a review
PublicationAir pollution becomes an increasing problem in the recent years. There is a need to develop more sensitive gas sensors. Much effort has been performed to develop different types of gas sensors, such as electrochemical sensors or polymer sensors. One of the most promising approaches to improve sensors performance is the application of the nanostructures as sensing materials. State of the art of quantum...
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Crystal Structure of N-(2-Benzoyl-4,5-dimethoxyphenethyl)-2-phenylacetamide
PublicationThe crystal structure of N-(2-benzoyl-4,5-dimethoxyphenethyl)-2-phenylacetamide indicates that the compound crystallizes in the monoclinic C2/c space group with eight molecules in the unit cell. The heteroatoms from the amide group form a chain of intermolecular N-H ··· O hydrogen bonds propagating along the b axis. The carbonyl group from the benzoyl substituent participates in short contacts with two H-atoms from the ethyl or...
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The Green Approach to the Synthesis of Bio-Based Thermoplastic Polyurethane Elastomers with Partially Bio-Based Hard Blocks
PublicationBio-based polymeric materials and green routes for their preparation are current issues of many research works. In this work, we used the diisocyanate mixture based on partially bio-based diisocyanate origin and typical petrochemical diisocyanate for the preparation of novel bio-based thermoplastic polyurethane elastomers (bio-TPUs). We studied the influence of the diisocyanate mixture composition on the chemical structure, thermal,...
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Determination of Glycerol, Propylene Glycol, and Nicotine as the Main Components in Refill Liquids for Electronic Cigarettes
PublicationRefill liquids for electronic cigarettes are an important area of research due to the health safety and quality control of such products. A method was developed for the determination of glycerol, propylene glycol, and nicotine in refill liquids using liquid chromatography, coupled with tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode with electrospray ionisation (ESI). Sample preparation was based...
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Microextraction Techniques Used in the Procedures for Determining Organomercury and Organotin Compounds in Environmental Samples
PublicationDue to human activities, the concentrations of organometallic compounds in all parts of the environment have increased in recent decades. The toxicity and some biochemical properties of mercury and tin present in the environment depend on the concentration and chemical form of these two elements. The ever-increasing demand for determining compounds at very low concentration levels in samples with complex matrices requires...
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Comparative study on fracture evolution in steel fibre and bar reinforced concrete beams using acoustic emission and digital image correlation techniques
PublicationIn recent decades, the demand for sustainable construction practices has increased, but raw materials such as reinforcing steel remain scarce. Therefore, steel fibres have emerged as a popular and sustainable choice in the construction industry, offering a cost-effective alternative to traditional steel bar reinforcement for both flatwork and elevated structures. The purpose of this study is therefore to compare the performance...
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Developments in ultrasound-assisted microextraction techniques for isolation and preconcentration of organic analytes from aqueous samples
PublicationThe great potential of ultrasonic assistance in sample preparation, especially extraction, is being recognized. In this review, we discuss the applications of ultrasonic radiation in assisting microextraction. Topics covered include ultrasound-assisted emulsification microextraction, ultrasound-assisted-emulsification-dispersive liquid-liquid microextraction, and ultrasound-assisted hollow-fiber liquid-phase microextraction with...
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NATURAL DEEP EUTECTIC SOLVENTS IN EXTRACTION PROCESS
PublicationDeveloping new, eco-friendly solvents which would meet technological and economic demands is perhaps the most popular aspects of Green Chemistry. Natural deep eutectic solvents (NADES) fully meet green chemistry principles. These solvents offer many advantages including biodegradability, low toxicity, sustainability, low costs and simple preparation. This paper provides an overview of knowledge regarding NADES with special emphasis...
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Surface-Plasmon-Coupled Emission of Rhodamine 110 in a Silica Nanolayer
PublicationThe first observation of strong directional surface-plasmon-coupled emission (SPCE) of Rhodamine 110 in silica nanofilms deposited on silver nanolayers is reported. The preparation of the material is described in detail. The intensity of SPCE exceeds 10 times that of free space fluorescence and total linear light polarization in the SPCE ring is observed. A new experimental setup and an original data collection method is presented....
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Studies on applicability of new solid-phase microextraction and determination of short - chain monocarboxylic acids
PublicationA convenient approach to monitor the short-chain monocaroboksylic acids (SCAMs) in different samples is gas chromatography (GC) preceded by sample preparation based on solid-phase microextraction (SPME). The fiber with polar coatings were used to extract the SCAMs from headspace of liquid and solid samples. Recently polimeric ionic liquid (PIL) fiber coatings have been proposed to extract volatile organic compounds, minly polar...
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Starch–metal complexes and metal compounds
PublicationRecently, metal derivatives of starch evoked considerable interest. Such metal derivatives can take a form of starch compounds bearing metal atoms and metal carrying moieties either covalently bound or complexed. Starch metal complexes may have a character of either Werner, inclusion, sorption or capillary complexes. In this publication, preparation, structure, properties and numerous current and potential applications of those...
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A hyperelastic model for soils with stress-induced and inherent anisotropy
PublicationIn this paper, modelling of the superposition of stress-induced and inherent anisotropy of soil small strain stiffness is8presented in the framework of hyperelasticity. A simple hyperelastic model, capable of reproducing variable stress-induced9anisotropy of stiffness, is extended by replacement of the stress invariant with mixed stress–microstructure invariant to10introduce constant inherent cross-anisotropic component. A convenient...
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Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-Cooling Function
PublicationThe nonlinear phenomena which associate with magnetoacoustic waves in a plasma are analytically studied. A plasma is an open system with external inflow of energy and radiation losses. A plasma’s flow may be isentropically stable or unstable. The nonlinear phenomena occur differently in dependence on stability or instability of a plasma’s flow. The nonlinear instantaneous equation which describes dynamics of nonwave entropy mode...
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Monitoring Steel Bolted Joints during a Monotonic Tensile Test Using Linear and Nonlinear Lamb Wave Methods: A Feasibility Study
PublicationThe structural integrity of steel bolted joints may be compromised due to excessive loading. Therefore, condition assessment and the detection of potential defects before they cause a failure have become a major issue. The paper is focused on the condition monitoring of a bolted lap joint subjected to progressive degradation in a tensile test. The inspection used Lamb waves propagated through the overlap area. Wave propagation...
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Strong-coupling superconductivity of SrIr2 and SrRh2 : Phonon engineering of metallic Ir and Rh
PublicationExperimental and theoretical studies on superconductivity in SrIr2 and SrRh2 Laves phases are presented. The measured resistivity, heat capacity, and magnetic susceptibility confirm the superconductivity of these compounds with Tc = 6.07 and 5.41 K, respectively. Electronic structure calculations show that the Fermi surface is mostly contributed by 5d (4d) electrons of Ir (Rh), with Sr atoms playing the role of electron donors....
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Sounding of Layered Marine Bottom - Model Investigations
PublicationThe necessary actions connected with interpretations of examining of physical properties of sea bottom structure is developing of proper procedure of modeling of the layered structure. The implementation of the acoustic waves for the determination of seabed stratification requires a precise diagnosis of the topic from both the theoretical and practical side. Little differences between the parameters of sediments, as well as irregular...
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Impact of surface skin temperature change on blood flow characteristics in palm
PublicationHeating a human palm during 3 minutes period causes changes in superficial skin temperature and leads to thermoregulation system response. The response time and level of flow characteristics change depend on the subject hand size and health of his vascular tree. A solution of Pennes bioheat propagation model was analyzed in order to see how much heat has to be transferred into the tissue to extort the observable reaction. The reflective...
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The Examination of the Upper Layers of the Seabed by the Means of the Acoustic Methods
PublicationPropagation 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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Performance of Noise Map Service Working in Cloud Computing Environment
PublicationIn the paper a noise map service designated for the user interested in environmental noise subject is presented. It is based on cloud computing. Noise prediction algorithm and source model, developed for creating acoustic maps, are working in cloud computing environment. In the study issues related to noise modeling of sound propagation in urban spaces are discussed with a special focus on road noise. Examples of results obtained...
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Searching of the buried objects in the sea bottom by means of noninvasive methods
PublicationSearching of objects on the seabed or under its surface currently is a challenge for a number of researchers interested in the sea bottom. The problem relates to the objects on the depths of up to several tens of meters from the surface of the seabed. Finding the objects is the subject of interest for a wide group of users starting from archaeologists, and ending on groups interested in marine safety, as well as in military application...
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Crank–Nicolson FDTD Method in Media Described by Time-Fractional Constitutive Relations
PublicationIn this contribution, we present the Crank-Nicolson finite-difference time-domain (CN-FDTD) method, implemented for simulations of wave propagation in media described by time-fractional (TF) constitutive relations. That is, the considered constitutive relations involve fractional-order (FO) derivatives based on the Grünwald-Letnikov definition, allowing for description of hereditary properties and memory effects of media and processes....
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Finite element/mode-matching analysis of ferrite/dielectric line junctions of arbitrary cross-section
PublicationThis paper is focused on the analysis of line junctions obtained as a cascade of dielectric and ferrite guides of arbitrary cross-section. The main application of such structures is nonreciprocal devices such as isolators, circulators, or phase shifters. The efficient finite element/mode-matching approach is proposed to the analysis of such structures. In this approach, thefiniteelementmethod is applied todetermine propagation...
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Damage Analysis of Tensioning Cable Anchorage Zone of a Bridge Superstructure, Using CDP Abaqus Material Model
PublicationNumerical analysis of the tensioning cables anchorage zone of a bridge superstructure is presented in this paper. It aims to identify why severe concrete cracking occurs during the tensioning process in the vicinity of anchor heads. In order to simulate the tensioning, among others, a so-called local numerical model of a section of the bridge superstructure was created in the Abaqus Finite Element Method (FEM) environment. The...
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Measurement of Impulse Response of Shallow Water Communication Channel by Correlation Method
PublicationPerformances of underwater acoustic communication (UAC) systems are strongly related to specific propagation conditions of the underwater channel; conditions that can additionally change in time due to the movement of the acoustic system transmitter and receiver or to reflection by underwater objects of the transmitted signal. The time-varying impulse response is a comprehensive description of dynamically changing transmission...
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Planning, Configuration and Usefulness of Microseismic Monitoring on Eastern-Europe Platform – Example from East Pomerania
PublicationThe microseismic monitoring is a method of monitoring of fracture propagation during hydraulic fracturing process. The method uses array of geophones to localize micro tremors induced by liquid pumped underground at high rate and pressure. The acquired information helps to optimize fracturing process and prevents fracture growth to aquifer levels. It proved to be useful on several unconventional hydrocarbon reservoirs in the USA....
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Uncertainty of the liquid mass flow measurement using the orifice plate
PublicationThe article presents an estimation of measurement uncertainty of a liquid mass flow using the orifice plate. This subject is essential because of the widespread use of this type of flow meters. Not only the quantitative estimation but also the qualitative results of those measurements are important. To achieve these results the authors of the paper propose to use the theory of uncertainty. The article shows the analysis of the...
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Transiluminacyjne monitorowanie stanu przestrzeni podpajęczynówkowej
PublicationTransiluminacja tkanek ludzkiego ciała w celach diagnostycznych jest stosowana od ponad stu lat. Metoda transiluminacji w bliskiej podczerwieni z rozpraszaniem zwrotnym (NIRT-BSS) umożliwia ciągłe, bezinwazyjne monitorowanie zmian szerokości przestrzeni podpajęczynówkowej, które może być cennym narzędziem w ocenie zagrożenia obrzękiem mózgu. W rozprawie przedstawiono optyczny model rozchodzenia się promieniowania podczerwonego...
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THERMOMECHANICAL PERFORMANCE OF FLEXIBLE POLYURETHANE FOAMS AS A FUNCTION OF THE ISOCYANATE INDEX
PublicationPolyurethane foams are very versatile materials applied in different branches of industry. Their popularity is attributed, among others, to the flexibility in engineering their mechanical performance by the adjustment of their formulations. One of the most crucial factors is the isocyanate index, determining the ratio between the free hydroxyl and isocyanate groups present in the polyurethane system. By the change of this ratio,...
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Spectroscopic properties of Rhodamine B entrapped in hybrid porous nanolayers at high dye concentration
PublicationThe preparation procedure and characterization of Rhodamine B entrapped in zirconia, silica and mixed silica–zirconia nanolayers is described. The nanolayers were produced by the sol–gel spin-coating technique. The pronounced effect of the dye concentration on the absorption and fluorescence spectra as well as on time-resolved fluorescence spectra was found. The results show that the aggregation of Rhodamine B is stronger in silica...
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An efficient and convenient synthesis of unsymmetrical disulfides from thioacetates
PublicationWe have developed convenient methods for the synthesis of functionalized unsymmetrical dialkyl disulfides under mild conditions in very good yields. The designed method is based on the reaction of (5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)-disulfanyl derivatives 1 with functionalized alkyl thiolate anions, generated in situ from thioacetates2and sodium methoxide or butylamine. The developed method allows the preparation...
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Efficient Synthesis of Functionalized Unsymmetrical Dialkyl Trisulfanes
PublicationWe have developed a convenient method for the synthesis of functionalized unsymmetrical dialkyl trisulfanes under mild conditions in very good yields. The designed method is based on the reaction of (5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)-disulfanyl derivatives with alkyl disulfanyl anions generated in situ from S-acetyl disulfanyl derivatives and sodium methoxide. The developed method allows for the preparation of...
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Novel and Efficient Synthesis of Unsymmetrical Trisulfides
PublicationWe have developed a convenient method for the synthesis of unsymmetrical trisulfides under mild conditions in very good yields. The designed method is based on the straightforward preparation of 1-[(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)trisulfanyl]dodecane from readily available 5,5-dimethyl-2-sulfanyl-2-thioxo-1,3,2-dioxaphosphorinane, sulfur dichloride (SCl2) and dodecane-1-thiol. The unsymmetrical trisulfides can...
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Anion recognition by n,n'-diarylalkanediamides
PublicationThe preparation of N,N'-diarylalkanediamides from respective aliphatic dicarboxylic acidesand 4-nitroaniline via microwave-promoted reactions is presented. The most positive effect of microwave irradiation was observed for N,N'-bis(4-nitrophenyl)butanediamide. Anion binding studies on the obtained diamides were carried out in DMSO and acetonitrile using UV-vis and 1H NMR spectroscopy. A mechanism for selective fluoride recognition...
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Badanie i analiza efektywności radiolokalizowania obiektów w środowisku wewnątrzbudynkowym
PublicationW ramach rozprawy doktorskiej przeprowadzono badania i analizę efektywności radiolokalizowania obiektów w środowisku wewnątrzbudynkowym, które cechują szczególne warunki propagacyjne fali elektromagnetycznej. Konsekwencją tych warunków jest częste zawyżanie radiowych pomiarów odległości, służących do wyznaczania położenia obiektów. W rezultacie wartość średnia błędów tych pomiarów jest większa od zera, a ich rozkład jest różny...
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Exergetic Analysis of the nCO2PP Cycle with Particular Reference to the Exergy Destruction of Sewage Sludge Due to Gasification
PublicationAn exergy analysis is carried out on the negative CO2 emission gas power plant (nCO2PP), which integrates the process sections of fuel preparation, power generation and carbon capture. Processes of exergy destruction are studied with particular focus on the process in the gasification unit of the fuel preparation section, where a large amount of exergy is destroyed in various chemical reactions from sewage sludge to producer gas...
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Determination of the active ingredient in pharmaceutical gel formulation by NIR spectroscopy
PublicationPharmaceuticals of their intended must be thoroughly controlled. The traditional analytical methods are very costly and time consuming. NIR spectroscopy allows to analyze pharmaceutical materials very quickly and with very low costs. First pharmaceutical applications of the NIR spectroscopy appeared with some incuriosity in the late 1960s. Application of NIR in the contemporary pharmaceutical industry is very large. The most common...
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Toward Polyethylene–Polyester Block and Graft Copolymers with Tunable Polarity
PublicationThe synthesis and characterization of polyethylene–polyester block and graft copolymers and their potential as compatibilizers in polyethylene-based polymer blends are being described. The various routes to functionalized polyethylenes and the corresponding block/graft copolymers have been compared and evaluated for their scalability to industrial scale production. Hydroxyl chain-end and randomly OH-functionalized HDPE as well...
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Lessons learned during SRAD hybrid motor development
PublicationStudent Researched and Developed (SRAD) hybrid rocket motor H-15 with total impulse of 15 $kNs$ was built. First version of the engine has average thrust of 3 $kN$, the second, improved one is prepared with an aim to have average thrust of 5 $kN$. Engine development was started from scratch and went through phases of: definition of design assumptions and constraints, numerical modelling to predict engine performance, CAD and CAM...
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Evaluation of mercury content in combustible tobacco products by employing cold vapor atomic absorption spectroscopy and considering the moisture content: a comprehensive study
PublicationPlants are mainly made up of water, which constitutes between 80 and 90% of their weight. Moisture factor comes across as one of the most important in tobacco products. Rapid determination of moisture content in tobacco products comes at neces- sity in any tobacco management plants (before and after production). Therefore, the concern has been raised in this study to evaluate the moisture content in four kinds of combustible tobacco...
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Towards azeotropic MeOH-MTBE separation using pervaporation chitosan-based deep eutectic solvent membranes
PublicationDeep eutectic solvents (DESs) are a new class of solvents that can offset some of the major drawbacks of common solvents and ionic liquids. When dealing with the preparation of dense membranes, the use of DESs is still challenging due to their low compatibility with the polymer phase. In this research, a novel L-proline:sulfolane (molar ratio 1:2) DES was synthesized and used for the preparation of more sustainable bio-based membranes...
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Surface treatment of C80U steel by long CO2 laser pulses
PublicationThe paper presents the results of laser-melted C80U steel. The processed steel was placed between two permanent magnets and laser beam whose scanning velocity was 10 mm/s. CO2 laser beam was working in pulse mode. Pulses were generated at 100% of the average preset power of 700W, with 45 ms irradiation, zero interval between pulses and beginning of pulse repetition upon the achievement of the average laser power. During the operation,...
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Styrene Oxidation by Copper(II) Complexes Salen-Type Encapsulated into Nay Zeolite
PublicationThe copper(II) complex with a Schiff-base salen-type ligand has been encapsulated in the nanopores of a NaY zeolite by using two different methodologies, the flexible ligand and in situ complex preparation methods. The encapsulated and non-encapsulated copper(II) complexes were screened as catalysts for styrene oxidation by using TBHP as the oxygen source in acetonitrile solvent. Under the optimized conditions, the catalysts exhibited...
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Experimental test of nonclassicality with arbitrarily low detection efficiency
PublicationWe theoretically introduce and experimentally demonstrate the realization of a nonclassicality test that allows for arbitrarily low detection efficiency without invoking an extra assumption of independence of the devices. Our test and its implementation is set in a prepare-and-measure scenario with an upper limit on the classical communication capacity of the channel through which the systems are communicated. The essence for our...
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Novel and Efficient Methods for the Synthesis of Symmetrical Trisulfides
PublicationWe have developed a convenient methods for the synthesis of symmetrical trisulfides under mild conditions in very good yields. The described methods are based on the straightforward preparation of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-disulfanyl derivatives from readily available 5,5-dimethyl-2-sulfanyl-2-thioxo-1,3,2-dioxaphosphorinane or bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl) disulfide. The symmetrical...
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Numerical modeling of sound intensity distributions around acoustic transducer
PublicationThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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COMMENTS ON EXISTING ANALYTICAL SOLUTIONS TO THE WAVE-INDUCED CYCLIC RESPONSE OF A POROUS SEABED OF INFINITE THICKNESS
PublicationThis paper deals with the wave-induced cyclic response of a porous seabed (by means of oscillating parameters: pore-fluid pressure, soil displacement components, effective normal stress and shear stress components) due to a surface sinusoidal water-wave propagating over a seabed of infinite thickness. The main existing analytical solutions to the governing problem are critically discussed, pointing out their meaningful errors and...
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DYNAMIC RESPONSE OF FORUM GDANSK STRUCTURE DUE TO RAIL TRAFFIC
PublicationThe paper presents the study of the impact of vibration induced by the movement of the railway rolling stock on the Forum Gdańsk structure. This object is currently under construction and is located over the railway tracks in the vicinity of the Gdańsk Główny and Gdańsk Śródmieście railway stations. The analysis covers the influence of vibrations on the structure itself and on the people within. The in situ measurements on existing...
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Application of chromogenic dye in biogenic amines determination using spectrophotometry
PublicationBiogenic amines content can be the source of information in the field of freshness and suitability of certain foods for consumption. However, most analytical methods for their determination require complicated sample preparation and expert knowledge. Because of that, a novel approach based on chromogenic dye application was proposed. After the SN1 reaction of an amine with S 0378 dye, the absorbance of the solution was measured...
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Materiały stosowane do wytwarzania implantów kości
PublicationMateriały stosowane do wytwarzania implantów kostnych muszą być biokompatybilne, nietoksyczne, bioaktywne oraz wykazywać odpowiednie właściwości mechaniczne, takie jak wytrzymałość na ściskanie, na zginanie oraz sztywność i twardość. Gama stosowanych materiałów jest bardzo szeroka, obejmuje metale, polimery, ceramikę oraz ich kompozyty. Każdy z tych materiałów ma swoje mocne i słabe strony. Praca stanowi przegląd materiałów stosowanych...