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Wyniki wyszukiwania dla: PREPARATION
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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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Geographic information system for remote integration of diverse under-water acoustic sensor data
PublikacjaMaritime and port areas throughout the world are exposed to many different hazards, like pollution, terrorism and natural disasters. Early detection, identification and preparation of appropriateesponse strategies is especially important in the case of semi-enclosed basins like the Baltic Sea, mainly due to the marine ecosystems' continuous absorption of pollutants including oil, heavy metals and chemicals. Many of those agents...
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Synthesis and structure of Bi 5 FeTi 3 O 15 ceramics
PublikacjaAim of the present research was to fabricate and study crystal structure and phase composition of Bi5FeTi3O15 (BTFO) ceramics exhibiting Aurivillius - type structure. By means of simultaneous thermal analysis and X-ray diffraction analysis the process of synthesis of BTFO ceramics has been studied. Mixed oxide method followed by pressureless sintering was used for ceramics preparation. Three endothermic thermal effects have been...
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Failures and a concept of corrosion protection system for spiral classifiers at KGHM Polska Miedź S.A. Ore Concentration Plant
PublikacjaThe Ore Concentration Plant, where the process of flotation is carried out as well as the final production of copper concentrate, plays a key role in the entire production line of KGHM Polska Miedź S.A. Majority of operations related to the run-of-mine preparation to copper flotation enrichment are carried out in a water environment. The maintaining of production process continuity requires to pursue minimisation of many production...
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Analytical Strategies and Applications in Lipidomics
PublikacjaLipidomics is a field of study aiming at a comprehensive analysis of a set of lipids in biological systems. This includes both quantitative and qualitative characterization of lipid profiles, comparative studies of lipidomes, and analysis of lipid-protein interactions. Lipids are structurally diversified that make their analysis a challenging task. The constant advances in analytical technologies, especially in the field of high-performance...
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Evaluation of structural and electrical properties of multicomponent spinel oxide thin films deposited via spray pyrolysis technique
PublikacjaThis work reports the preparation of (Mn,Co,Fe,Ni,Cr)3O4 high-entropy spinel oxide in the form of a ~ 500 nm thin film utilising a facile spray pyrolysis technique. The structural and electrical properties of the layers were characterised after exposure to temperatures in the range of 400–900 ◦C. The as-deposited layers were amorphous, and crystallised upon heat treatment at 500 ◦C. Microstructural analyses proved a homogeneous...
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Profiling of polar ionogenic metabolites in Polish wines by capillary electrophoresis-mass spectrometry
PublikacjaThe composition of wine is determined by a complex interaction between environmental factors, genetic factors (i.e., grape varieties), and winemaking practices (including technology and storage). Metabolomics using NMR spec-troscopy, GC-MS, and/or LC-MS has shown to be a useful approach for assessing the origin, authenticity, and quality of various wines. Nonetheless, the use of additional analytical techniques with complementary...
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Ferrofluids based analytical extractions and evaluation of their greenness
PublikacjaFerrofluids are stable dispersions of magnetic nanoparticles in a carrier liquid. They have attracted considerable attention in analytical extractions as they combine fluid-like properties with magnetic character, providing magnetic control over the extraction process. The synthesis of ferrofluids is very straightforward, and it generally involves the preparation of magnetic nanoparticles, their coating, and then mixing in a suitable...
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A Universal Gains Selection Method for Speed Observers of Induction Machine
PublikacjaProperties of state observers depend on proper gains selection. Each method of state estimation may require the implementation of specific techniques of finding those gains. The aim of this study is to propose a universal method of automatic gains selection and perform its verification on an induction machine speed observer. The method utilizes a genetic algorithm with fitness function which is directly based on the impulse response...
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Digital Filtering of Railway Track Coordinates in Mobile Multi–Receiver GNSS Measurements
PublikacjaThe article discusses an important issue in connection with the technique of mobile Global Navigation Satellite System (GNSS) measurements of railway track coordinates, which is digital filtering performed to precisely determine railway track axes. For this purpose, a measuring technique is proposed which bases on the use of a measuring platform with a number of appropriately distributed GNSS receivers, where two of them determine...
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Właściwości elektryczne szkło-ceramiki zawierającej ferroelektryczną fazę BiV
PublikacjaKompozyty szklano - ceramiczne zawierające nanokryształy posiadają właściwości fizyczne, które nie są możliwe do uzyskania w innych materiałach. Dzięki możliwości wytworzenia szkło - ceramik posiadających kryształy o różnej wielkości (nano, mikro...) i różnorodnego typu, można w istotny sposób kontrolować właściwości elektryczne takich materiałów. Stała dielektryczna faz ferroelektrycznych jest bardzo wrażliwa na zmiany rozmiarów...
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Problemy planowania strategii i zagospodarowania przestrzennego w zarządzaniu rozwojem obszarów metropolitalnych
PublikacjaCelem pracy jest rozpoznanie i usystematyzowanie problemów związanych z planowaniem kompleksowej strategii zarządzania rozwojem obszarów metropolitalnych i sporządzaniem planu zagospodarowania przestrzennego tych obszarów. Problemy planowania rozumiane są jako trudności, dylematy i wątpliwości związane z różnymi aspektami procesu planistycznego. Autor nawiązuje do cech obszarów metropolitalnych oraz typowych problemów rozwiązywanych...
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Hydrogen production from biomass using dark fermentation
PublikacjaHydrogen applicability in the power, chemical and petrochemical industries is constantly growing. Efficientmethods of hydrogen generation from renewable sources, including waste products, are currently being de-veloped, even though hydrogen is mainly produced through steam reforming or thermal cracking of natural gasor petroleum fractions. In paper alternative methods of hydrogen production with a particular emphasis on darkfermentation...
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SURFACTANTS IN KLODNICA RIVER (KATOWICE, POLAND). PART II. QUATERNARY AMMONIUM COMPOUNDS
PublikacjaThe paper presents methods of determination of analytes of the cation group (alkyl benzyl dimethyl ammonium (BDDA-C12-C16), alkyl trimethyl ammonium (TMA), hexadecyl piridinium (HP)) in surface water and bottom sediment samples. In the sample preparation phase the solid phase extraction (SPE) or accelerated solvent extraction/ultrasound assisted extraction (ASE/UAE)-SPE technique was used and in the identification phase and quantitative...
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Quantum and carbon dots conjugated molecularly imprinted polymers as advanced nanomaterials for selective recognition of analytes in environmental, food and biomedical applications
PublikacjaSamples with complex matrix analyzed during explanation of pathogenesis of various diseases and food or environmental monitoring request advanced analytical and instrumental devices. Among the materials used for described purposes, quantum (QDs) or carbon dots (CDs) layered by molecularly imprinted polymer (MIP) shells have gained widespread attention. Unique optical and physicochemical properties of QDs/CDs together with high...
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Determination of eight artificial sweeteners and common Stevia rebaudiana glycosides in non-alcoholic and alcoholic beverages by reversed-phase liquid chromatography coupled with tandem mass spectrometry.
PublikacjaThe method for the determination of acesulfame-K, saccharine, cyclamate, aspartame, sucralose, alitame, neohesperidin dihydrochalcone, neotame and five common steviol glycosides (rebaudioside A, rebaudioside C, steviol, steviolbioside and stevioside) in soft and alcoholic beverages was developed using high-performance liquid chromatography and tandem mass spectrometry with electrospray ionisation (HPLC-ESI-MS/MS). To the best of...
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Properties of ordered titanium templates covered with Au thin films for SERS applications
PublikacjatCurrently, roughened metal nanostructures are widely studied as highly sensitive Raman scattering sub-strates that show application potential in biochemistry, food safety or medical diagnostic. In this workthe structural properties and the enhancement effect due to surface enhanced Raman scattering (SERS) ofhighly ordered nano-patterned titanium templates covered with thin (5–20 nm) gold films are reported.The templates are formed...
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Development of potential candidate reference materials for drugs in bottom sediment, cod and herring tissues
PublikacjaRegular use of a reference material and participation in a proficiency testing program can improve the reliability of analytical data. This paper presents the preparation of candidate reference materials for the drugs metoprolol, propranolol, carbamazepine, naproxen, and acenocoumarol in freshwater bottom sediment and cod and herring tissues. These reference materials are not available commercially. Drugs (between 7 ng/g and 32...
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Organic semiconductor rubrene thin films deposited by pulsed laser evaporation of solidified solutions
PublikacjaOrganic semiconductor rubrene (C42H28) belongs to most preferred spintronic materials because of the high charge carrier mobility up to 40 cm2(V·s)-1. However, the fabrication of a defect-free, polycrystalline rubrene for spintronic applications represents a difficult task. We report preparation and properties of rubrene thin films deposited by pulsed laser evaporation of solidified solutions. Samples of rubrene dissolved in aromatic...
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Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part I: Liquid chromatography-tandem mass spectrometry analysis
PublikacjaLiquid chromatography-tandem mass spectrometry with electrospray ionization (HPLC-ESI–MS/MS) methods were developed for the simultaneous determination of 42 flavouring compounds and nicotine in liquids for e-cigarettes. The chromatographic separation was performed using an Ace® Ultracore™ SuperC18™ (100 × 2.1 mm, 2.5 μm) column in both acidic and alkaline pH conditions to separate all the compounds. A simple “dilute & shoot” approach...
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Extraction with environmentally friendly solvents
PublikacjaThe ever-increasing demand for determining compounds at low concentration levels in complex matrices requires a preliminary step of analytes isolation/enrichment in order to employ a detection technique characterized by high sensitivity at low LOQ. Sample preparation is considered as crucial part of analytical procedures. Previously the parameter of “greenness” is as important as selectivity in order to avoid using harmful organic...
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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
PublikacjaPolycyclic 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...
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Proton Conducting Ceramic Powder Synthesis by a Low Temperature Method
PublikacjaMolten salt synthesis (MSS) is a simple method for the preparation of ceramic powders with specific morphology. The main role of the molten salts is to increase the reaction rate and lower the reaction temperature. It occurs because of much higher mobility of reactants in the liquid medium than in the solid state. In this work the molten salt synthesis was applied to produce ceramic powders of La0995Ca0005NbO4 and BaCe09−xZrxY01O3....
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Analysis of Airport Runoff Waters
PublikacjaA particularly important facet of airport operation is the impact of the pollution caused byrunoff waters. Runoff waters at an airport may contain relatively high concentrations of differentcontaminants resulting from the various aspects of its operation: de/anti-icing operations,washing and cleaning operations, spills of fuel and lubricants, exhaust fumes, and weed removal.The pollution caused by airport operations affects soil,...
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Analysis of MArkers of Exposure to Constituents of Environmental Tobacco Smoke (ETS)
PublikacjaTobacco smoke is a complex mixture of more than 4000 chemical compounds, many of which are harmful to human health. These compounds belong to various chemical classes, including amides, imides, lactams, carboxylic acids, aldehydes, ketones, alcohols, phenols, amines, hydrocarbons, ethers, and inorganic compounds. There are three types of tobacco smoke streams: the mainstream, the sidestream, and environmental tobacco smoke (ETS)....
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Raman Spectra Measurements for Chemical Identifications - Aspect of Uncertainty Sources and Reduction of Their Effects
PublikacjaRaman spectrometers enable fast and non-contact identification of examined chemicals. These devices measure Raman spectra and compare with the spectra database to identify unknown and often illicit chemicals (e.g. drugs, explosives) usually without any sample preparation. Raman spectra measurements are a challenge due to noise and interferences present outside the laboratories (field applications). The design of a portable Raman...
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Studies on applicability of new solid-phase microextraction fibers for the selective extraction and determination of short - chain monocarboksylic acids
PublikacjaShort-chain monocarobxylic acids, sometimes referred to as volatile fatty acids (VFA), are a group of low molecular weight alkyl monocarboxylic acids that are widely distributed within the environment. These molecules contain any from 2 to 8 carbon atoms and originate from the anaerobic biodegradation of organic matter such as carbohydrates, proteins, and fats. These compounds are commonly found in the effluents from animal farming,...
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Mass Spectrometry-Based Direct Analytical Techniques
PublikacjaDirect analysis of samples is considered as one of the most environmentally sustainable solutions in analytical chemistry. In the ideal case, such solutions do not require sample preparation and analytes separation steps, therefore do not consumpt harmful substances (or consumpt only minimum amounts of them) and do not generate hazardous waste. Technical solutions for direct analysis also offer miniaturized and field-portable analyzers...
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Challenges and Possibilities of Deep Eutectic Solvent-Based Membranes
PublikacjaDeep eutectic solvents (DES) are a category of a new class of solvents that can overcome some of the main drawbacks of typical solvents and ionic liquids (ILs). DES have been widely investigated and applied by the research community in several applications since their invention. Over the past years, the use of DES has been directed to the production of new materials and items for new products and processes. This is the case for...
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Uczenie maszynowe do samoorganizacji systemów rozproszonych w zastosowaniach gospodarczych
PublikacjaW pracy omówiono uczenie maszynowe do samoorganizacji systemów rozproszonych w zastosowaniach gospodarczych ze szczególnym uwzględnieniem sieci neuronowych do predykcji finansowych oraz szacowania ratingu przedsiębiorstw. Oprócz sieci neuronowych, istotną rolę w przygotowaniu i testowaniu informatycznych systemów finansowych może pełnić programowanie genetyczne. Z tego powodu omówiono uczenie maszynowe w aplikacjach konstruowanych...
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The cement-bone bond is weaker than cement-cement bond in cement-in-cement revision arthroplasty. A comparative biomechanical study
PublikacjaThis study compares the strength of the native bone-cement bond and the old-new cement bond under cyclic loading, using third generation cementing technique, rasping and contamination of the surface of the old cement with biological tissue. The possible advantages of additional drilling of the cement surface is also taken into account. Femoral heads from 21 patients who underwent a total hip arthroplasty performed for hip arthritis...
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Speech Analytics Based on Machine Learning
PublikacjaIn this chapter, the process of speech data preparation for machine learning is discussed in detail. Examples of speech analytics methods applied to phonemes and allophones are shown. Further, an approach to automatic phoneme recognition involving optimized parametrization and a classifier belonging to machine learning algorithms is discussed. Feature vectors are built on the basis of descriptors coming from the music information...
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Biomechanical properties of 3D-printed bone models
PublikacjaBone lesions resulting from large traumas or cancer resections can be successfully treated by directly using synthetic materials or in combination with tissue engineering methods (hybrid). Synthetic or hybrid materials combined with bone tissue’s natural ability for regeneration and biological adaptation to the directions of loading, allow for full recovery of its biological functions. Increasing interest in new production methods...
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Photochemical Rearrangement of a 19-Membered Azoxybenzocrown: Products and their Properties
PublikacjaThe preparation and characterization of products of the chemical and photochemical rearrangements of a 19-membered o,o'-azoxybenzocrown were presented. In photochemical rearrangement, besides expected product i.e. 19-membered o-hydroxy-o,o'-azobenzocrown (19-o-OH), obtained under defined conditions with 75% yield, also other macrocyclic products were isolated and identified, namely: 19-membered p-hydroxy-o,o'-azobenzocrown (19-p-OH),...
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Insights into the Thermo-Mechanical Treatment of Brewers’ Spent Grain as a Potential Filler for Polymer Composites
PublikacjaThis paper investigated the impact of twin-screw extrusion parameters on the properties of brewers’ spent grain. The chemical structure, antioxidant activity, particle size, and color properties, as well as the emission of volatile organic compounds during extrusion, were investigated. The main compounds detected in the air during modifications were terpenes and terpenoids, such as α-pinene, camphene, 3-carene, limonene, or terpinene....
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Lipidomics of Staphylococcus aureus – a new insight into the antibiotic resistant phenotype
PublikacjaStaphylococcus aureus is an aggressive pathogen responsible for a variety of diseases, in cluding life-threatening sepsis. Many strains of these bacteria are resistant to multiple classes of antibiotics, which is a substantial clinical problem in the treatment of S. aureus infections. We developed a comprehensive untargeted lipidomic workflow, including sample preparation, liquid chromatography-quadrupole-time-of-flight mass spectrometry...
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Progress, Challenge, and Perspective of Bimetallic TiO2-Based Photocatalysts
PublikacjaBimetallic TiO2-based photocatalysts have attracted considerable attention in recent years as a class of highly active catalysts and photocatalysts under both UV and Vis light irradiation. Bimetallic noble metal structures deposited on TiO2 possess the ability to absorb visible light, in a wide wavelength range (broad LSPR peak), and therefore reveal the highest level of activity as a result of utilization of a large amount of...
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Temperature influence on tire/road noise evaluated by the drum method
PublikacjaAmbient air and road surface temperatures substantially affect the road vehicle noise emission. The temperature influence on tire/road noise depends mainly on tire-road combination. It is different for dense and porous pavements, for bituminous and cement ones. It differs also depending on tires. The correction procedures for temperature effect are still under consideration and preparation. Laboratory experiment was prepared to...
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The Analysis of Vodka: A Review Paper
PublikacjaVodka is the most popular alcoholic beverage in Poland, Russia and other Eastern European countries, made from ethyl alcohol of agricultural origin that has been produced via fermentation of potatoes, grains or other agricultural products. Despite distillation and multiple filtering, it is not possible to produce 100 % ethanol. The solution with a minimum ethanol content of 96 %, which is used to produce vodkas, also contains trace amounts...
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Steroid Sulfatase Inhibitors Based on Phosphate and Thiophosphate Flavone Analogs
PublikacjaA series of phosphate and thiophosphate flavone derivatives were synthesized and biologically evaluated in vitro for inhibition of steroid sulfatase (STS) activity. The described synthesis includes the straightforward preparation of 7-hydroxy-2-phenyl-4H-chromen-4-one 3a, 2-(4-fluorophenyl)-7-hydroxy-4H-chromen-4-one 3b, 7-hydroxy-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one 3c, 7-hydroxy-2-(p-tolyl)-4H-chromen-4-one 3d modified...
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Effect of modified soybeen oil amount on rheological characteriza-tion of polyurethane pre-polymers
PublikacjaPolyurethanes (Pu’s) are the polymeric materials which have got urethane groups in the structure. The properties of Pu’s depend both on the method of preparation and monomers used. Polyurethanes are produced by two methods known as one step or two step method called as “pre-polymers method”, especially for the case of segmented polyurethanes (SPU’s). These materials are thermoplastic block copolymers of the (AB)n type consisting...
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Regeneration of marine engine valves using laser surfacing
PublikacjaThis article presents an analysis of the applicability of laser surfacing of the exhaust valve face of a marine diesel engine using cobalt-based powder. After preparation by machining, the selected valves were subjected to laser surfacing using a high-power ROFIN DL020 laser. The EuTroLoy 16012 powder was used in the surfacing process. One of the valves was cut and subjected to metallographic examination and hardness measurements,...
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Biosynthetic and synthetic access to amino sugars.
PublikacjaAmino sugars are important constituents of a number of biomacromolecules and products of mi crobial secondary metabolism, including antibiotics. For most of them, the amino group is located at the positions C1, C2 or C3 of the hexose or pentose ring. In biological systems, amino sugars are formed due to the catalytic activity of specific aminotransferases or amidotransferases by introducing an amino functionality derived from L-glutamate...
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Portable Electronic Nose Based on Electrochemical Sensors for Food Quality Assessment
PublikacjaThe steady increase in global consumption puts a strain on agriculture and might lead to a decrease in food quality. Currently used techniques of food analysis are often labour-intensive and time-consuming and require extensive sample preparation. For that reason, there is a demand for novel methods that could be used for rapid food quality assessment. A technique based on the use of an array of chemical sensors for holistic analysis...
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Bio-based semi-aromatic polyesters for coating applications
PublikacjaLinear and branched bio-based semi-aromatic (co)polyesters were evaluated as resins for solvent-basedand powder coatings. Dimethyl-2,5-furandicarboxylate (DMF), 2,3-butanediol and various multifunc-tional comonomers were used to synthesize amorphous hydroxyl-end-capped (co)polyesters. The resinswere cross-linked using the -caprolactam blocked trimer of isophorone diisocyanate. Both the solvent-based and powder coatings proved to...
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Determination of organophosphorus and organonitrogen pesticides in water samples
PublikacjaPesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in sources of drinking water, essential to life, is a particular danger. In water, these compounds can undergo transformations, leading to the production of substances of even greater toxicity. Legal regulations are in force, stipulating the highest permissible level of...
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Engineering Au nanoparticle arrays on SiO2 glass by pulsed UV laser irradiation
PublikacjaWe study semi-regular arrays of Au nanoparticles (NP) obtained via UV laser irradiation of thin Au films on glass substrate. The NP structures are prepared from films of a thickness up to 60 nm produced by discharge sputtering or pulsed laser deposition, and annealed by nanosecond laser pulses at 266 or 308 nm, respectively, at fluencies in the range of 60-410 mJ/cm2. For the rare- and close-packed NP structures, consistent description...
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Thermal, electrical, and magnetic properties of Fe2O3–PbO–SiO2 glass prepared by traditional melt-quenching and twin roller fast-cooling methods
PublikacjaIn this study, Fe–Pb–Si oxide glasses containing between 12.5 and 17.5 mol% Fe2O3 were prepared using two different methods comprising traditional melt-quenching and twin roller fast-cooling techniques. The topography and structure of the materials obtained were characterized by X-ray powder diffraction and scanning electron microscopy. All of the materials were found to be amorphous. The topography of most of the glasses comprised...
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Comparative Greenness Evaluation
PublikacjaGreenness of analytical procedure is multivariable aspect as many greenness criteria should be taken into consideration. On the other hand, modern analytical chemistry offers dozens of analytical procedures, based on different sample preparation and final determination techniques that are used for the determination of a given analyte in a given matrix. For such complex decision-making processes, multi-criteria decision analysis...
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RESEARCH ON ORGANIC COATINGS DESIGNED FOR UNDERWATER APPLICATIONS
PublikacjaUnderwater steel structures require periodic maintenance. In the case of vessels, anti-corrosion works are carried out in the shipyard, where very good conditions for applying organic protective coatings can be provided. Very good surface preparation can be obtained by the use of abrasive blasting. The well-prepared metal surface is free from impurities (particularly inorganic salts). Suitable conditions for the application and...