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Wyniki wyszukiwania dla: chemical properties
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Giant Reed (Arundo donax L.) Fiber Extraction and Characterization for Its Use in Polymer Composites
PublikacjaThis work describes an extraction method for giant reed fibers from stems and leaves based on chemical soaking and crushing through a rolling mill. Obtained fibers, together with the shredded plant (stems + leaves), are characterized in terms of chemical composition, thermal stability, morphology, and crystallinity. Mechanical properties of fibers have also been assessed (single fiber tensile tests). The results show that the proposed...
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Protective and Suppressing Electromagnetic Interference Properties of Epoxy Coatings Containing Nano-Sized NiZn Ferrites
PublikacjaNano-crystalline ferrites with the chemical formula NixZn(1−x)Fe2O4, where x = 0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a co-precipitation method. The obtained ferrites were investigated by X-ray diffraction (XRD). The corrosion inhibiting behavior of nano-sized ferrites was tested using carbon steel samples and 10% aqueous ferrite extracts. Results were compared with previous data obtained for micro-sized ceramic ferrites....
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A literature survey of the influence of preform reheating and stretch blow molding with hot mold process parameters on the properties of PET containers. Part I.
PublikacjaThe hot fill process is an inexpensive conventional filling technology for high-acidity products (pH < 4.5). It allows certain drinks (sensitive beverages such as fruit and vegetable juices, nectars, soft drinks, vitaminized water) to be stored at ambient temperature without the need for chemical preservatives. The primary feature of the bottles used in the hot fill process is their temperature stability, i.e. the ability to retain...
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A literature survey of the influence of preform reheating and stretch blow moulding with hot mould process parameters on the properties of PET containers – part 2.
PublikacjaThe hot fill process is an inexpensive conventional filling technology for high-acidity products (pH < 4.5). It allows certain drinks (sensitive beverages such as fruit and vegetable juices, nectars, soft drinks, vitaminised water) to be stored at ambient temperature without the need for chemical preservatives. The primary feature of the bottles used in the hot fill process is their temperature stability, i.e. the ability to retain...
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Visible light photocatalysis employing TiO2/SrTiO3-BiOI composites: Surface properties and photoexcitation mechanism
PublikacjaA series of binary TiO2/SrTiO3 and ternary TiO2/SrTiO3_BiOI composites have been synthesized using multistep preparation method. Characterization of the obtained photocatalysts covered complex analysis including morphology + y (SEM), BET specific surface area, porosity, optical properties (DRS), chemical composition of surface (XPS), crystal structure and crystal size (XRD). UV–vis and Vis ligh induced photocatalytic activity was...
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Chemical analysis of the Au-Ag nanoaloys
Dane BadawczeThe nanostructures of AuAg nanoalloys were prepared by sequential sputtering of gold and silver thin films. Single layer thickness was usually 2.8 nm were deosted by magnetron sputtering method in a Ar plasma. As deposited layers were annealed in Ar atmosphere at 550 degress for 15 minutes. For XPS measurements five samples were selected: pure gold...
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Imaging and chemical investigation of silver coating
Dane BadawczeThe recovery of silver from materials such as plates, still used in clinical radiography [1], or scrap jewelery is still very popular. The subject of the research, part of which was microscopic imaging, was to recreate the behavior of an electrochemically deposited silver coating. The copper electrodes were covered with a layer of silver obtained from...
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Depth chemical profile in a CeIr3 sample
Dane BadawczeThe polycrystalline sample of CeIr3 used in the present studies was synthesized by arc-melting cerium (4N) and iridium (3N5) in an arc furnace on a water-cooled copper hearth using a tungsten electrode under a high purity argon atmosphere. A piece of zirconium was used as an oxygen getter. First, a button of Ir was prepared by arc-melting the iridium...
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Honey as an indicator of heavy metals in the environment
PublikacjaHoney bees collect nectar, pollen and honeydew to produce bee products. One of them is honey, which due to chemical composition and properties is considered by human as a valuable food product. When honey bees collect substrates to produce honey they can bring contaminants to the hive. The presence of xenobiotics in bee products may lower their quality and devalue their properties, and also endanger human health. Many scientists...
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Thermoplastic polyurethanes derived from petrochemical or renewable resources: A comprehensive review
PublikacjaThermoplastic polyurethanes (TPUs) materials are obtained by the reaction of polyol (ether-, ester-, and carbonate-based diols with average molecular weight in the range from 1,000 to 3,000 g/mol) with aliphatic or aromatic diisocyanates. Synthesized materials consist of the hard and soft segments which are separated in different level. All mechanical and thermal properties of TPUs depend on the chemical structure of used monomers,...
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Diamine derivatives of dimerized fatty acids and bio-based polyether polyol as sustainable platforms for the synthesis of non-isocyanate polyurethanes
PublikacjaA series of environmentally friendly non-isocyanate polyurethanes (NIPUs) were successfully prepared via the polyaddition reaction of bio-based polyether polyol-based cyclic carbonate with diamine derivative of dimerized fatty acids. The syntheses of NIPUs were realized by the three-step method in the absence of toxic solvents and, importantly, the process of carbonation did not require the use of elevated pressure. The effect...
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Crystal structures of aminotransferases Aro8 and Aro9 from Candida albicans and structural insights into their properties
PublikacjaAminotransferases catalyze reversibly the transamination reaction by a ping-pong bi-bi mechanism with pyridoxal 5′-phosphate (PLP) as a cofactor. Various aminotransferases acting on a range of substrates have been reported. Aromatic transaminases are able to catalyze the transamination reaction with both aromatic and acidic substrates. Two aminotransferases from C. albicans, Aro8p and Aro9p, have been identified recently, exhibiting...
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Structure and performance properties of environmentally-friendly biocomposites based on poly(ɛ-caprolactone) modified with copper slag and shale drill cuttings wastes
PublikacjaThe potential application of two types of industrial wastes, drill cuttings (DC) and copper slag (CS), as silica-rich modifiers of poly(ɛ-caprolactone) (PCL) was investigated. Chemical structure and physical properties of DC and CS fillers were characterized using X-ray diffractometer, X-ray fluorescence spectroscopy, particle size and density measurements. PCL/DC and PCL/CS composites with a variable content of filler (5 to 50...
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Obrony prac doktorskich na Wydziale Chemicznym
WydarzeniaDn. 21.01.2022 r. o godz. 10.15 w Audytorium 1.4 Wydziału Chemicznego PG (budynek nr 5) odbędzie się w trybie hybrydowym publiczna obrona pracy doktorskiej mgr inż. Moniki Baranowskiej
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Ecotoxicity and chemical sediment data classification by the useof self-organising maps
PublikacjaArtykuł 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
PublikacjaOkreślono 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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Quality Assurance and Quality Control in the Analytical Chemical Laboratory: A Practical Approach.
PublikacjaNowe opracowanie książkowe z zakresu QA/QC to praktyczny podręcznik zarówno dla studentów jak i pracowników laboratoriów. Opisano systemu jakości wyników pomiarów analitycznych i poszczególnych jego składników: spójności pomiarowej, niepewności pomiaru, walidacji procedury analitycznej, materiałów odniesienia i badań międzylaboratoryjnych. Opisano i przedstawiono narzędzia statystyczne służące do obliczania parametrów walidacyjnych,...
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Arsenic concentrations in Baltic Sea sediments close to chemical munitions dumpsites
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Chemical characterization of dew water collected in different geographic regions of Poland
PublikacjaPrzedstawiono wyniki badań składu chemicznego próbek rosy zebranych na terenie Polski w okresie od 2004 do 2006 roku na terenach: rolniczym (Wrocław, Dziemiany), miejskim w strefie wybrzeża (Gdańsk, Gdynia, Sopot), miejskim, położonym poza strefą wybrzeża (Bytów, Kraków, Mława). Próbki rosy badano w celu uzyskania informacji o składzie jakościowym i ilościowym. Celem badań było dostarczenie informacji o składzie chemicznym (i wybranych...
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Improving of Cherry Fruit Quality and Bearing Regularity by Chemical Thinning with Fertilizer
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Chemical and thermal stability of core-shelled magnetite nanoparticles and solid silica
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Deep sea habitats in the chemical warfare dumping areas of the Baltic Sea
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Application of Chemical Sensors and Olfactometry Method in Ecological Audits of Degraded Areas
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Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons
PublikacjaChemical 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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Evaluation of Chemical Changes in Laboratory-Induced Colistin-Resistant Klebsiella pneumoniae
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Chemical and magnetic functionalization of graphene oxide as a route to enhance its biocompatibility
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Development of Chemical Tools to Monitor Human Kallikrein 13 (KLK13) Activity
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Polylactide Films with the Addition of Olive Leaf Extract—Physico-Chemical Characterization
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Green chemical and hybrid enzymatic pretreatments for lignocellulosic biorefineries: Mechanism and challenges
PublikacjaThe greener chemical and enzymatic pretreatments for lignocellulosic biomasses are portraying a crucial role owing to their recalcitrant nature. Traditional pretreatments lead to partial degradation of lignin and hemicellulose moieties from the pretreated biomass. But it still restricts the enzyme accessibility for the digestibility towards the celluloses and the interaction of lignin-enzymes, nonproductively. Moreover, incursion...
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Exposure status of sea-dumped chemical warfare agents in the Baltic Sea
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Application of Coordination Compounds with Transition Metal Ions in the Chemical Industry—A Review
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A Molecular dynamics study of the influence of chemical reduction on the structure of amorphous germania
PublikacjaPraca 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.
PublikacjaOtrzymano 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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Biological fluids as a source of information on the exposure of man to envinonmental chemical agents.
PublikacjaWiele 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
PublikacjaArtykuł 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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Preliminary studies of the chemical composition and cytotoxic activity of Hottonia palustris herb
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Ab initio chemical kinetics of Isopropyl acetate oxidation with OH radicals
PublikacjaGlobal 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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Application of electrochemical sensors and sensor matrixes for measurement of odorous chemical compounds
PublikacjaIn 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
PublikacjaWe 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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Control of mass concentration of reagents by sound in a gas with nonequilibrium chemical reactions
PublikacjaThe 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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Recent Progress on Hydrogen Storage and Production Using Chemical Hydrogen Carriers
PublikacjaDepleting fossil fuel resources and anthropogenic climate changes are the reasons for the intensive development of new, sustainable technologies based on renewable energy sources. One of the most promising strategies is the utilization of hydrogen as an energy vector. However, the limiting issue for large-scale commercialization of hydrogen technologies is a safe, efficient, and economical method of gas storage. In industrial practice,...
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Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons
PublikacjaChemical 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
PublikacjaCoal 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
PublikacjaThere 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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ELECTRICAL CONDUCTIVITY AND pH IN SURFACE WATER AS TOOL FOR IDENTIFICATION OF CHEMICAL DIVERSITY
PublikacjaIn 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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Polymers doped by Ca or P. Chemical composition investigations
Dane BadawczeThe calcium and phosphorus doped polyurethane polymers (PU) were analyzed by XPS method. A series of samples with various content of Ca and P dopand - from 0% up to 21%) were selected for measutements. The chemical composition and valence state of elements were measurements using OmicronNatechnology UHV system wih Argus hemispherical photoelectron...
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Structural, thermal and physico-mechanical properties of polyurethane/brewers’ spent grain composite foams modified with ground tire rubber
PublikacjaIn this work, brewers’ spent grain (BSG) and ground tire rubber (GTR) waste fillers were applied as low-cost reinforcement phase in rigid polyurethane foam (PUR). PUR/BSG/GTR composites were prepared by a single step method, using polyglycerol as partial substitute of commercially available petrochemical polyols. Foaming parameters, chemical structure, dynamic mechanical properties, thermal stability, physico-mechanical properties...
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Microwave assisted liquefaction with crude glycerol as a potential method of brewer's spent grain utylization
PublikacjaBrewer's spent grain was applied as a low-cost industrial type of lignocellulose biomass in a liquefaction and solvent: biomass ratio on the efficiency of the process, chemical structure and basic properties of obtained prepared polyols and soil residues shed light on the biomass degradation mechanism through application of microwaves and further reaction of degradation products with solvent particles.
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Effect of hydroxylated soybean oil and bio-based propanediol on the structure and thermal properties of synthesized bio-polyurethanes
PublikacjaThe aim of this work was to obtain bio-polyurethanes using synthetic compounds and bio-components, i.e. bio-glycols. Bio-polyurethanes were prepared by means of the prepolymer method. Prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 75% by weight of commercial polyether and 25% by weight of hydroxylated soybean oils (H2 or H3), the latter being obtained in the reaction with...
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The influence of polypropylene-block/graft-polycaprolactone copolymers on melt rheology, morphology, and dielectric properties of polypropylene/polycarbonate blends
PublikacjaThe paper discusses the relationship between rheology and morphology of immiscible polypropylene (matrix))/polycarbonate (dispersed phase) blends compatibilized with novel polypropylene-polycaprolactone block and graft copolymers. Transmission electron microscopy (TEM) experiments revealed uniform droplet morphologies and a reduction of the average size of the dispersed phase upon addition of the compatibilizer. The results suggested...