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wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: CHEMICAL STRUCTURE
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Chemical modification of tannins from Acacia mearnsii to produce formaldehyde free flocculant
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A Comprehensive Review on Shilajit: What We Know about Its Chemical Composition
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The Use of Chemical Sensors to Monitor Odour Emissions at Municipal Waste Biogas Plants
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Uncertainty in maritime risk analysis: Extended case study on chemical tanker collisions
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Characteristics, Chemical Modification Processes as well as the Application of Silica and its Modified Forms
PublikacjaThe 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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Effect of chemical composition and microstructure on mechanical properties of BA1055 bronze sand castings.
PublikacjaW pracy wykazano, że nawet małe zmiany w składzie chemicznym brązu aluminiowego BA1055 mają istotny wpływ na strukturę i właściwości mechaniczne odlewów. Określono wpływ wydzieleń międzymetalicznej fazy κ na właściwości odlewów z brązu BA1055 stosowanego na pędniki okrętowe.
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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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Phytoplankton communities of polar regions–Diversity depending on environmental conditions and chemical anthropopressure
PublikacjaThe polar regions (Arctic and Antarctic) constitute up to 14% of the biosphere and offer some of the coldest and most arid Earth's environments. Nevertheless several oxygenic phototrophs including some higher plants, mosses, lichens, various algal groups and cyanobacteria, survive that harsh climate and create the base of the trophic relationships in fragile ecosystems of polar environments. Ecosystems in polar regions are characterized...
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Chapter 11 – Application of Chemical Sensors and Sensor Matrixes to Air Quality Evaluation
PublikacjaIndoor and outdoor air quality is one of the key factors influencing human health. However, air quality evaluation is not easy task. Air is a complex system, which is subjected to changes even within short period of time. Progress in analytical methods and analytical tools provides increasingly more reliable information on the condition and quality of indoor and outdoor air. This progress, however, generates an increase in the...
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Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition
PublikacjaAmines are important biological compounds, and so their analysis and monitoring in various matrices is worthy of investigation and development.Due to the polar nature of amines, chromatographic analysis of free amines is generally unsatisfactory owing to adsorption and decomposition of the solute on the column, resulting in peak tailing and losses. Therefore, many derivatization reactions are employed to reduce the polarity, improve...
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A novel luminescent chemical sensor for the determination of Pb 2+ and Cu 2+ ions
PublikacjaSilica xerogel surface grafted with aminopropyl (PrNH2) groups was additionally treated by cetyltrimethylammonium bromide (CTAB) surfactant and ascorbic acid (asc) in alkaline solution. This material symbolized as SiO2-PrNH2-CTAB/asc, proved to be a stable luminescent material, exhibited an emission band peaked at 393 nm under excitation wavelength 335 nm. Time evolution of the band intensity suggests changes of defect concentration...
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Chemical, thermal and laser processes in recycling of photovoltaic silicon solar cells and modules
PublikacjaIn 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....
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Anion recognition by phosphonium calix[4]arens: synthesis and physico-chemical studies
Publikacjap-tert-butylcalix[4]arenes in the cone conformation, di-and tetra substituted at the narrow rim with charged phosphonium groups have been synthesies and characterised.
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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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Study of Phase and Chemical Composition of Bi1-xNdxFeO3 Powders Derived by Pressureless Sintering
PublikacjaIn the present paper studies on Bi1xNdxFeO3 for x =0.1-0.4 are reported. The mixed oxide method followed with pressureless sintering was employed for ceramics fabrication. Thermal behavior of stoichiometric mixtures of simple oxide powders, viz. Bi2O3, Nd2O3 and Fe2O3 was studied by simultaneous thermal analysis. It was found that with an increase in neodymium content the weight loss increased from 0.75% to 3.16% for x =0.1 and...
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Method for determination of the chemical composition of phases of the iron catalyst precursor for ammonia synthesis
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Thermodynamics of Chemical Processes in the System of Nanocrystalline Iron–Ammonia–Hydrogen at 350 °C
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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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Elimination of the chemical and microbiological pollutants in the modernized watewater treatment plant ''Wschód'' in Gdańsk.
PublikacjaW 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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Centre of Excellence in Envirinmental Analysis and Monitoring at the Chemical Faculty of the Gdańsk University of Technology.
PublikacjaPrzedstawiono działalność Centrum (CEEAM) utworzonego 01.01.2003 na Wydziale Chemicznym PG. Opisano cel powstania, zrealizowane zadania i plany.
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Balance of pesticides mass in gas, liquid and solid phase after their chemical degradation.
PublikacjaOpisano metodę usuwania pestycydów z wody przy zastosowaniu fotodegradacji (UV) i katalizatora (TiO2). Efektywność procesu usuwania pestycydów była kontrolowana przy zastosowaniu chromatografu gazowego z detektorem wychwytu elektronów. Oznaczano zawartość pestycydów w wodzie, a także zaadsorbowanych na powierzchni stałej, oraz w fazie gazowej. Największa zawartość pestycydów znajdowała się na fazie stałej, następnie w cieczy i...
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Physical, Chemical and Biological Changes in the Gulf of Gdańsk Ecosystem (Southern Baltic Sea).
PublikacjaPrzedstawiono 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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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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TEST METHOD FOR DETERMINING THE CHEMICAL EMISSIONS OF A MARINE DIESEL ENGINE EXHAUST IN OPERATION
PublikacjaThe article briefly describes the problem of air pollution caused by sea-going ships and the resulting restrictions on the emission of toxic and harmful chemical compounds in the exhaust of marine engines, introduced by the International Maritime Organization (IMO) under the International Convention for the Prevention of Sea Pollution from Ships (MARPOL 73/78). Such emissions provide a significant metrological problem, not only...
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A New Approach to Chemical Recycling of Polyamide 6.6 and Synthesis of Polyurethanes with Recovered Intermediates
PublikacjaA new efficient method for the chemical decomposition of polyamide 6.6 by the glycolysis and amino-glycolysis processes was proposed. The glycolysis was conducted using the mass excess of ethylene glycol (EG) as a decomposing agent in the presence of a catalyst. Also, a mixture of EG and triethylenetetramine was used as another decomposing agent in the amino- glycolysis process. The described process of decomposition did not...
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Lipids and Food Quality
PublikacjaThis chapter deals with lipids present in food as well as their chemical, biological, and functional properties. The chapter begins with a presentation of the main groups of lipids including their chemical structure and physical properties. The physical properties of lipids affecting food processing are covered. Then, the role of lipids in human nutrition is presented. This is followed by a description of the undesirable changes...
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Imaging of morphological and physicochemical changes occuring in the structure of austenitic steel due to the thermal sensitization
Dane BadawczeIn polycrystalline materials, grain boundaries are always where phenomena such as surface diffusion, sedimentation and corrosion occur. They have a significant impact on the macroscopic properties of the construction material [1]. In addition to inhomogeneities such as manganese sulphide inclusions formed during the metallurgical process, interfacial...
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Pt-rich intermetallic APt8P2 (A = Ca and La)
PublikacjaThe combination of experimental and theoretical investigation of two new Pt-rich intermetallic compounds: APt8P2 (A = Ca and La) is presented, including solid-state synthesis, crystal structure determination, physical properties characterization and chemical bonding analysis. APt8P2 was obtained through the high-temperature pellet synthesis. According to both single crystal and powder X-ray diffraction results, APt8P2 crystallize...
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Preparation of porous TiO2 films by means of pulsed laser deposition for photocatalytic applications
PublikacjaIn this work the preparation and structure properties of porous thin films of TiO2 were investigated. The films were produced by means of the pulsed laser deposition technique using laser pulses at 266nm (10Hz) and at fluencies of 1-3.5J/cm2. The process was performed in vacuum using O2 buffer gas and films were deposited on the SiO2 glass or Si substrate. X-ray diffraction (XRD) and Raman analysis of the structure and chemical...
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The influence of the Cu2O deposition method on the structure, morphology and photoresponse of the ordered TiO2NTs/Cu2O heterojunction
PublikacjaThe increased interest in highly ordered titania structures exhibiting tubular shape that could be directly formed onto the stable substrate is related with the intensive research on their modification enabling absorption of light within the wide solar spectrum and its further conversion into electric or chemical energy. Among others, formation of uniform 3D heterojunctions based on the TiO2 nanotubes attracts attention since porous...
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Susceptibility to Degradation in Soil of Branched Polyesterurethane Blends with Polylactide and Starch
PublikacjaA very important method of reducing the amount of polymer waste in the environment is the introduction to the market of polymers susceptible to degradation under the influence of environmental factors. This paper presents the results of testing the susceptibility to degradation in soil of branched polyesterurethane (PUR) based on poly([R,S]-3-hydroxybutyrate) (R,S-PHB), modified with poly([D,L]-lactide) (PLA) and starch (St). Weight...
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Recycling of Polyurethanes Containing Flame-Retardants and Polymer Waste Transformed into Flame-Retarded Polyurethanes
PublikacjaThe growing number of polyurethanes (PUs) produced every year has developed methods for their mechanical and chemical recycling which yield valuable products like substitutes for commercial polyols or flame-retardants. PUs can be produced in different shapes and forms (i.e., elastomers, flexible or rigid foams, coatings, etc.) using several different components (i.e., di- or polyisocyanates, ester- or ether-based polyols, low-molecular...
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Polyurethane Glycerolysate as a Modifier of the Properties of Natural Rubber Mixtures and Vulcanizates
PublikacjaChemical recycling of polyurethanes can be realized in several different ways, but the most important methods are glycolysis and glycerolysis. Both methods permit recovery of polyols (when the process is realized with the mass excess of depolymerizing agent) or substitutes of polyols, which contain urethane moieties in the main chains and terminate mainly in hydroxyl groups (when the process is realized with the mass excess of...
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Chestnut-Derived Activated Carbon as a Prospective Material for Energy Storage
PublikacjaIn this work, we present the preparation and characterization of biomass-derived activatedcarbon (AC) in view of its application as electrode material for electrochemical capacitors. Porouscarbons are prepared by pyrolysis of chestnut seeds and subsequent activation of the obtainedbiochar. We investigate here two activation methods, namely, physical by CO2and chemical usingKOH. Morphology, structure and specific surface area (SSA)...
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Effects of stressful physico-chemical factors on the fitness of the plant pathogenic bacterium Dickeya solani
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High resolution model for assessment of contamination by chemical warfare agents dumped in the Baltic Sea
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The Tribological, Physico-Chemical and Rheological Properties of Lubricating Grease Produced on Epoxy Resin Base
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BelBuk System—Smart Logistics for Sustainable City Development in Terms of the Deficit of a Chemical Fertilizers
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Chemical Composition and Antioxidant Properties of Powders Obtained from Different Plum Juice Formulations
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Chemical recycling of plastic waste as a mean to implement the circular economy model in the European Union
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TG-FTIR, DSC and quantum chemical studies of the thermal decomposition of quaternary methylammonium halides
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Decision Support System to Improve the Effectiveness of Chemical Control Against Cutworms in Sugar Beet
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Chemical modification of natural immunomodulators tuftsin and muramyl dipeptide significantly influence their biological activity
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Chemical and Mechanical Pressure-Induced Photoluminescence Tuning via Structural Evolution and Hydrostatic Pressure
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