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Search results for: chemical synthesis
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Evaluation of Chemical Changes in Laboratory-Induced Colistin-Resistant Klebsiella pneumoniae
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Influence of chemical composition of amide block on the thermal properties and structure of terpolymers
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Preliminary studies of the chemical composition and cytotoxic activity of Hottonia palustris herb
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A Molecular dynamics study of the influence of chemical reduction on the structure of amorphous germania
PublicationPraca poświęcona jest badaniom struktury blisko- i średniozasięgowej redukowanego amorficznego tlenku germanu o składzie 1Ge 1GeO2 za pomocą symulacji dynamiczno-molekularnych. Symulacje MD realizowano w zespole mikrokanonicznym (NVE), z wykorzystaniem dwuciałowego potencjału oddziaływania miedzyatomowego Borna-Mayera-Hugginsa. Wyraźnie widoczna tendencja do aglomeracji neutralnych atomów Ge została porównana z tendencją do aglomeracji...
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A Chemical Recognition Element for Lithium Ions Based on Optical Electronic Absorption.
PublicationOtrzymano próbki kserożeli techniką zol-żel. Otrzymane materiały zastosowano do konstrukcji czujników optycznych. Rolę elementu rozpoznającego w uzyskanych próbkach pełnią chromogeniczne etery koronowe zawierające w makro pierścieniu dwie grupy azowe oraz resztę fenolu. W obecności soli metali I grupy układ u okresowego obserwowano zmiany w widmach absorpcyjnych. Dla matrycy zawierającej jako materiał czujnikowy 21-członową...
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Ab initio chemical kinetics of Isopropyl acetate oxidation with OH radicals
PublicationGlobal reactivity descriptors of isopropyl acetate (IPA) and thermo-kinetic aspects of its oxidation via OH radicals have been studied. Transition state theory (TST) was utilized to estimate the bimolecular rate constants. Ten oxidation pathways have been investigated, and all of them are exothermic. The potential energy diagram has been sketched using different pre- and post-reactive complexes for all reaction pathways. Rate coefficient...
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Ecotoxicity and chemical sediment data classification by the useof self-organising maps
PublicationArtykuł dotyczy przedstawiania nowej interpretacji szacowania jakości osadów. To oryginalne podejście bada powiązania między parametrami ekotoksyczności (ostrej i chronicznej) i składnikami chemicznymi (zanieczyszczenia takie jak polichlorowane bifenyle, pestycydy, wielopierścieniowe węglowodory aromatyczne, metale ciężkie) próbek osadów Jeziora Turawskiego (Polska) poprzez zastosowanie samoorganizujących się map (SOM) wobec badanego...
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Chemical characterization of dew water collected in different geographic regions of Poland
PublicationOkreślono poziomy stężeń składników śladowych obecnych w próbkach rosy zebranych na terenach wyraźnie różniących się pod względem położenia geograficznego jak również poziomem antropopresji. Próbki rosy były zbierane na terenie ośmiu stacji pomiarowych w cyklu dobowym w okresie od sierpnia 2004 do listopada 2006 roku. W zależności od położenia miejsc zbierania próbek oraz charakteru tła emisji zanieczyszczeń dokonano podziału na...
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Control of mass concentration of reagents by sound in a gas with nonequilibrium chemical reactions
PublicationThe weakly nonlinear dynamics of a chemically reacting gas is studied. Nonlinear interaction of acoustic and nonacoustic types of motion are considered. We decompose the base equations using the relationships of the gas-dynamic perturbations specific for every type of motion. The governing equation for the mass fraction of a reagent influenced by dominating sound is derived and discussed. The conclusions concern the equilibrium...
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Application of electrochemical sensors and sensor matrixes for measurement of odorous chemical compounds
PublicationIn this paper describes the principle of operation of the electrochemical sensors and the sensor matrixes comprised of electrochemical sensors intended for measurement of odorous compounds. Critical comparison of these sensors’ advantages and disadvantages has been made. The fields of economy contributing to release of odours and the potential sources of their emission have been identified. Commercially available electrochemical...
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Tuning the ferromagnetic phase in the CDW compound SmNiC2 via chemical alloying
PublicationWe report a study on tuning the charge density wave (CDW) ferromagnet SmNiC2 to a weakly coupled superconductor by substituting La for Sm. X-ray diffraction measurements show that the doped compounds obey Vegard’s law, where La (Lu) alloying expands (shrinks) the lattice due to its larger (smaller) atomic size than Sm. In the series Sm1−xLaxNiC2, CDW transition (TCDW =148K) for SmNiC2 is gradually suppressed, while the ferromagnetic...
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ELECTRICAL CONDUCTIVITY AND pH IN SURFACE WATER AS TOOL FOR IDENTIFICATION OF CHEMICAL DIVERSITY
PublicationIn the present study, the creeks and lakes located at the western shore of Admiralty Bay were analysed. The impact of various sources of water supply was considered, based on the parameters of temperature, pH and specific electrolytic conductivity (SEC25). All measurements were conducted during a field campaign in January-February 2017. A multivariate dataset was also created and a biplot of SEC25 and pH of the investigated waters...
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Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons
PublicationChemical vapor transport (CVT) method is widely used for bulk black phosphorus (BP) fabrication. In this work, we demonstrate that CVT provides a route for the fabrication of BP nanoribbons and nanobelts. This method consists of a two-step procedure, including initial BP column growth using the CVT technique, followed by ultrasonic treatment and centrifugation. The obtained nanostructures preserve BP column dimensions, forming...
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Chemical analysis of low carbon content coals and their applications as dye adsorbent
PublicationCoal is primarily a fuel material but lately it has been utilized as an adsorbent for removing toxic metal ions. However, its usage for removing organic pollutants is not well studied. We report here a systematic study on the use of coal samples of varying carbon contents as adsorbents for removing Basic Blue 41 as a model cationic dye. The coal samples were collected from coal mines and were thoroughly characterized. The concentrations...
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Chemical Aspects of Biological Activity of Isothiocyanates and Indoles, the Products of Glucosinolate Decomposition
PublicationThere is growing evidence that cancer chemoprevention employing natural, bioactive compounds may halt or at least slow down the different stages of carcinogenesis. A particularly advantageous effect is attributed to derivatives of sulfur-organic phytochemicals, such as glucosinolates (GLs) synthesized mainly in Brassicaceae plant family. GLs are hydrolysed enzymatically to bioactive isothiocyanates (ITC) and indoles, which exhibit strong...
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Biological fluids as a source of information on the exposure of man to envinonmental chemical agents.
PublicationWiele związków (min. lotne związki chlorowcoorganiczne, metale) ma szkodliwy wpływ na tkanki i narządy organizmu ludzkiego, wywołując nieodwracalne zmiany chorobowe. W celu określenia zagrożenia zawodowego coraz częściej wykonuje się pomiar stężeń substancji chemicznych i ich metabolitów w płynach biologicznych - moczu, krwi, rzadziej w mleku matki, żółci, ślinie, czy też spermie. Aby oznaczyć poziomy tych stężeń, pobrane próbki...
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Investigations of dissimilar stainless steels welded joints for chemical tankers construction
PublicationArtykuł przedstawia właściwości mechaniczne złączy różnoimiennych stali typu duplex oraz austenitycznej typu 316L otrzymanych za pomocą spawania automatycznego łukiem krytym. Wykazano możliwość wykorzystania wysokowydajnej metody SAW w miejsce dotychczas stosowanych metod GTAW i GMAW do spawania blach zbiorników statków do przewozu chemikaliów.
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Development of Microstructured Carbon Coatings by Substrate-Catalytic CVD
PublicationCarbon nanostructured films were synthesized by chemical vapor deposition (CVD) on H18 stainless steel (AISI 440C) sheets with an H2/CH4/N2 gas mixture at various substrate temperatures. During the synthesis, the iron and chromium oxide layer was formed between the steel and carbonaceous layer. The carbon films exhibited wall-like and spherical morphologies and structures, as characterized by scanning electron microscopy and Raman...
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Meiothermus ruber cells as β-galactosidase activity biocatalyst
PublicationThe current study allowed to establish the possibility of using whole cells of thermophilic bacteria Meiothermus ruber as a biocatalyst with β-galactosidase activity. β-galactosidases are used for hydrolysis of lactose as well as for oligosaccharides synthesis. The advantages of using whole bacterial cells catalysis is not only elimination of tedious, expensive protein isolation and/or purification but also stabilization of enzymes...
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Investigation of H2:CH4 plasma composition by means of spatially resolved optical spectroscopy
PublicationThe system based on spatially resolved optical emission spectroscopy dedicated for in situ diagnostics of plasma assisted CVD processes is presented in this paper. Measurement system coupled with chemical vapour deposition chamber by dedicated fiber-optic paths enables investigation of spatial distribution of species densities (Hx, H+, CH, CH+) during chemical vapour deposition process. Experiments were performed for a various...
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A novel methodology for the enantiomeric resolution of methamphetamine, its precursors and intermediates by GC-MS
PublicationImpurity profiling and classification of abused drugs using chiral analytical techniques is of particular interest and importance because of the additional information obtained from this approach. When these methods are applied to the synthesis of illicitly used substances, they can supply valuable information about the conditions/chemicals used in the synthesis. In this study, simultaneous chiral separation of methylamphetamine,...
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Environmental impact and industrial development of biorenewable resources for polyurethanes
PublicationPolyurethanes are among the most developed types of polymers. They are produced from the three primary components, i.e., polyols, low-molecular-weight glycols used as chain extenders, and diisocyanates. Until recently, all these substrates have been obtained via petrochemical processes. A decrease in petroleum-based resources and new ecological trends in chemistry, chemical technology, and materials engineering have generated increasing...
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Elimination of the chemical and microbiological pollutants in the modernized watewater treatment plant ''Wschód'' in Gdańsk.
PublicationW artykule przedstawiono wyniki 2 letnich, kompleksowych badań efektywności zanieczyszczeń chemicznych, mikrobiologicznych i parazytologicznych w zmodernizowanej oczyszczalni ścieków ''Wschód'' w Gdańsku. Oceniono wpływ funkcjonowania układu generowania lotnych kwasów tłuszczowych na skuteczność usuwania związków biogennych oraz jego oddziaływanie na eliminację zanieczyszczeń biologicznych z oczyszczonych ścieków
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Chemometric exploration of sea water chemical component data sets with missing elements
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Morphologic, Phylogenetic and Chemical Characterization of a Brackish Colonial Picocyanobacterium (Coelosphaeriaceae) with Bioactive Properties
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Chemical modification of tannins from Acacia mearnsii to produce formaldehyde free flocculant
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Optical and chemical characterization of thin TiNx films deposited by DC-magnetron sputtering
PublicationThin titanium nitride (tinx) films were deposited on silicon substrates by means of a reactive dc-magnetron plasma. Layers were synthesized under various conditions of discharge power and nitrogen flows in two operation modes of the magnetron (the so-called "balanced" and "unbalanced" modes). The optical constants of the tinx films were investigated by spectroscopic ellipsometry (se). X-ray photoelectron spectroscopy (xps) was...
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Characteristics, Chemical Modification Processes as well as the Application of Silica and its Modified Forms
PublicationThe variety of chemical modifications of the surface of silica and its modified forms cause thesematerials to find a consistently wider scope of application. In the publication, the characteristicsof silica, silica gel, aerogel and xerogel are presented. The obtainment, application and propertiesof these materials are discussed. Methods of chemical modifications of surface structures withthe use of different chemical compounds...
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A Comprehensive Review on Shilajit: What We Know about Its Chemical Composition
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Preparation and characterization of silk fibroin/collagen sponge modified by chemical cross-linking
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INFLUENCE OF THE INTERMOLECULAR INTERACTION ON PHYSICO-CHEMICAL PROPERTIES OF CHITOSAN/HYALURONIC ACID BLENDS
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The Effects of Cross-Link Density and Chemical Exchange on Magnetization Transfer in Polyacrylamide Gels
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The Impact of Effective Microorganisms on Flesh Color and Chemical Composition of Raw Potato Tubers
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Influence of Hydrogenation on Morphology, Chemical Structure and Photocatalytic Efficiency of Graphitic Carbon Nitride
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Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites
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Identification of Novel Chemical Scaffolds Inhibiting Trypanothione Synthetase from Pathogenic Trypanosomatids
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Scaffolds Loaded with Dialdehyde Chitosan and Collagen—Their Physico-Chemical Properties and Biological Assessment
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Solvent effects on the nitrogen NMR chemical shifts in 1-methylazoles – a theoretical study
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Theoretical analysis of solvent effects on nitrogen NMR chemical shifts in oxazoles and oxadiazoles
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Physical, chemical and biochemical properties of Western Siberia Sphagnum and Carex peat soils
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Chemical Munitions Search & Assessment—An evaluation of the dumped munitions problem in the Baltic Sea
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The Use of Chemical Sensors to Monitor Odour Emissions at Municipal Waste Biogas Plants
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Thermodynamics of Chemical Processes in the System of Nanocrystalline Iron–Ammonia–Hydrogen at 350 °C
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Uncertainty in maritime risk analysis: Extended case study on chemical tanker collisions
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Consequences of New Approach of Chemical Stability Tests of Active Pharmaceutical Ingredients (APIs)
PublicationThere is a great need of broaden look on stability tests of active pharmaceuticalingredients (APIs) in comparison with current requirements contained in pharmacopeia.By usage of many modern analytical methods the conception of monitoring the changesof APIs during initial stage of their exposure to harmful factors has been developed. Newknowledge must be acquired in terms of identification of each degradation...
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Description of plants and assessment of chemical properties of three species from the Amelanchier genus
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Effect of substrate type on the field performance and chemical composition of highbush blueberry cv.Patriot
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Syntheses, structures and chemical properties of unsaturated oligo(alkylene-ester-ether)diols
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Physical, Chemical and Biological Changes in the Gulf of Gdańsk Ecosystem (Southern Baltic Sea).
PublicationPrzedstawiono fizyczne, chemiczne i biologiczne zmiany zachodzące w ekosystemie Zatoki Gdańskiej (Południowy Bałtyk. Opisano klimat (temp. wody, opady poziom morza, zasolenie), fluktuację stężeń związków biogennych (azotany,fosforany, krzemiany), poziom organicznych zanieczyszczeń (POP´s, PcB´, pestycydy, WWA) oraz zmiany w biologicznym życiu morza.
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Chemical, thermal and laser processes in recycling of photovoltaic silicon solar cells and modules
PublicationIn recent years, photovoltaic power generation systems have been gaining unprecedented attention as an environmentally beneficial method to solve the energy problem. From the economic point of view the pure silicon, which can be recapture from the used cells, is the most important material due to its cost and shortage. In the paper selected methods of used or damaged module and cells recycling and experimental results are presented....