Filters
total: 4057
filtered: 3388
-
Catalog
Chosen catalog filters
displaying 1000 best results Help
Search results for: COMPETITION PREPARATION
-
Composition and antimicrobial activity of fatty acids detected in the hygroscopic secretion collected from the secretory setae of larvae of the biting midge Forcipomyia nigra (Diptera: Ceratopogonidae)
PublicationThe hygroscopic secretion produced by the secretory setae of terrestrial larvae of the biting midge Forcipomyia nigra (Winnertz) was analysed using gas chromatography coupled with mass spectrometry (GC-MS). The viscous secretion is stored at the top of each seta and absorbs water from moist air. GC-MS analyses (four independent tests) showed that the secretion contained 12 free fatty acids, the most abundant of which were oleic...
-
Challenges in preparing honey samples for chromatographic determination of contaminants and trace residues
PublicationThe determination of contaminations and residues in honey is of growing concern over past few years, especially that these compounds can not only diminish beneficial properties of honey but more importantly, if present in significant amounts, can pose serious threat to human health. Since honey is characterized by complex composition of the matrix sample, it is often necessary to apply clean-up step, in order to eliminate interfering...
-
Ograniczenie trwałości skojarzeń ceramicznych w wyniku propagacji pęknięć powierzchniowych = Fatigue life limitation of ceramic materials due to surface crack propagation
PublicationPrzedstawiono krótką analizę literaturową dotyczącą mechanizmów propagacji pęknięć w materiałach ceramicznych oraz wyniki dotychczasowych badań doświadczalnych wybranych materiałów ceramicznych z uwzględnieniem wpływu pęknięć powierzchniowych na trwałość ceramicznych skojarzeń tocznych.
-
Damage detection in 3D printed plates using ultrasonic wave propagation supported with weighted root mean square calculation and wavefield curvature imaging
Publication3D printing (additive manufacturing, AM) is a promising approach to producing light and strong structures with many successful applications, e.g., in dentistry and orthopaedics. Many types of filaments differing in mechanical properties can be used to produce 3D printed structures, including polymers, metals or ceramics. Due to the simplicity of the manufacturing process, biodegradable polymers are widely used, e.g., polylactide (polylactide...
-
Introduction to MIP synthesis, characteristics and analytical application
PublicationOne of the trends in analytical chemistry is associated with designing and developing new types of sample preparation techniques, which might significantly increase the efficiency and selectivity of the analytes isolation or/and preconcentration process. One of the most widely employed solutions are selective sorption materials, defined as molecularly imprinted polymers (MIPs), as well as the sorbents with the molecular fingerprint....
-
Pharmaceutical and forensic drug applications of chiral supercritical fluid chromatography
PublicationTHE SUPERCRITICAL FLUID IS AN EXCELLENT CHOICE AS THE CHROMATOGRAPHIC MOBILE PHASE BECAUSE IT ALLOWS RAPID SEPARATION WITH HIGH EFFICIENCY AND APPLICATIONS INVOLVING ENANTIORESOLUTION ARE COMMON. SUPERCRITICAL FLUID CHROMATOGRAPHY (SFC) IS INCREASINGLY USED FOR ANALYTICAL, SEMI-PREPARATIVE AND PREPARATIVE PURIFICATION OF CHIRAL COMPOUNDS, INCLUDING PRODUCTION OF ENANTIOMERS THAT ARE MAINLY ENCOUNTERED DURING DRUG DEVELOPMENT. SFC...
-
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,...
-
Przydatność białka rybiego w postaci kolagenu lub żelatyny oraz polisacharydu - kapa-karagenu do wytwarzania aktywnych opakowań biodegradowalnych = Usefulness of fish collagen, gelatin and carrageenan for preparation of active biodegradable packages
PublicationSummary - The possibility of use of protein films made of fish collagen or gelatin as well as polysaccharide carrageenan films as carriers of enzymes (lysozyme or lysostaphyne), for preparation of microbiologically active packages, was investigated. It was found that crosslinking of such systems with N-[3(dimethylamino)propyl]-N'-ethylcarboimide (EDC) does not influence the activity of lysozyme immobilized in the films (Table 1)....
-
Method development and validation for optimized separation of quercetin derivatives in selected Potentilla species using high-performance thin-layer chromatography photodensitometry method
Publication -
Performance tuning of chitosan-based membranes by protonated 2-Pyrrolidone-5-carboxylic acid-sulfolane DES for effective water/ethanol separation by pervaporation
PublicationToday, the applicability of deep eutectic solvents (DES) in various fields, including membrane science and technology, is extensively investigated. In pioneering works, we have implemented different DES as a component of chitosan (CS)-based flat membranes for pervaporation (PV) separation. Herein, we present a new protonated (by sulphuric acid) 2-Pyrrolidone-5-carboxylic acid: sulfolane DES, as a green additive for its chemical...
-
Distinction of clenbuterol intake from drug or contaminated food of animal origin in a controlled administration trial – the potential of enantiomeric separation for doping control analysis
PublicationThe differentiation of clenbuterol abuse and unintentional ingestion by contaminated meat is crucial with respect to the valuation of an adverse analytical finding in human sports doping control. The proportion of the two enantiomers of clenbuterol may serve as potential discriminating parameter. For the determination of the individual enantiomers, specific methods were developed and validated for the different matrices under investigation...
-
Nowe metodyki oznaczania dodatków do paliw z zastosowaniem rozdzielenia wielopomiarowego = New procedures for fuel additives determination by multidimensional separation systems
PublicationW pracy przedstawiono wyniki badań nad opracowaniem metodyki oznaczania wybranych dodatków "myjących" w paliwie diesla. Porównano metodyki jednoetapowe z wykorzystaniem chromatografii gazowej z detektorem płomieniowo-jonizacyjnym (GC-FID) lub spektrometrem mas (GC-MS) oraz wysokosprawnej chromatografii cieczowej z detektorem UV z matrycą fotodiodową (HPLC-UV-DAD), z metodykami dwuetapowymi, w których do wstępnej izolacji składników...
-
Phenolic composition and antioxidant properties of polish blue-berried honeysuckle genotypes by HPLC-DAD-MS, HPLC postcolumn derivatization with ABTS or FC, and TLC with DPPH visualization
PublicationIn this study, different Polish cultivars of blue-berried honeysuckles (Lonicera caerulea L.), wild and bog bilberry, were analyzed for bioactive compounds. The chemical properties verified included composition of anthocyanins and other polyphenols, antioxidant activity, and profiles of antioxidants by HPLC postcolumn derivatization or TLC. The antioxidant activities of different blue-berried honeysuckle cultivars were similar...
-
Sources and composition of chemical pollution in Maritime Antarctica (King George Island), part 1: Sediment and water analysis for PAH sources evaluation in the vicinity of Arctowski station
PublicationThe paper presents a study regarding the identification of polycyclic aromatic hydrocarbons (PAHs) in fresh waters and surface sediments on the western shore of Admiralty Bay over four sampling seasons from 2017 to 2018. The results were compared to literature data from 2016 to provide a more comprehensive image of the environmental fate of PAHs over the years. The highest value of Σ PAHs was 82.9 ng/L and 445 ng/g dw in water...
-
The effect of exogenous application of methyl jasmonate on the lipid and carbohydrate content and composition of winter triticale (Triticosecale Wittm.) grain and the severity of fungal infections in triticale plants and grain
PublicationKernels of winter triticale (Triticosecale Wittm. cv. Dinaro) were analyzed. In the autumn of 2015, the effect of methyl jasmonate (MJ) on the germination of triticale kernels and the development of triticale seedlings was analyzed in a laboratory before kernels were sown in experimental plots. Kernels harvested from plots in August 2016 were analyzed to determine their lipid and carbohydrate content and composition and the severity...
-
Nowoczesne techniki przygotowania próbki do oznaczania analitów organicznych z zastosowaniem chromatografii gazowej. Część II. Aparatura. Modern techniques of preparation of samples for determining organic analytes by gas chromatography. Part II. Instrumentation.
PublicationW pracy dokonano przeglądu szerokiego spektrum technik przygotowania próbki ze szczególnym uwzględnieniem technik o charakterze prośrodowiskowym. Opisu technik dokonano pod kątem wykorzystywanych mechanizmów izolacji analitów oraz stosowanych rozwiązań aparaturowych.
-
Acute myocardial infarction reparation/regeneration strategy using Wharton’s jelly multipotent stem cells as an ‘unlimited’ therapeutic agent: 3-year outcomes in a pilot cohort of the CIRCULATE-AMI trial
Publication -
Optimal conditions of ramentaceone and plumbagin separation and isolation from carnivorous plants extracts using reverse phase-high performance liquid chromatography (RP-HPLC)
PublicationPreparatywna chromatografia cieczowa jest szczególnie przydatną techniką do rozdzielania i izolacji użytecznych ilości substancji z różnych skomplikowanych mieszanin. Praca prezentuje optymalne warunki rozdzielania i izolacji ramentaceonu i plumbaginy uwzględniając maksymalną selektywność rozdzielania naftochinonów od substancji balastowych z chloroformowych ekstraktów roślinnych D. aliciae i D. capensis z zastosowaniem techniki...
-
Optimal conditions of ramentaceone and plumbagin separation and isolation from carnivorous plants extracts using normal phase-high performance liquid chromatography (NP-HPLC)
PublicationPraca prezentuje optymalne warunki rozdzielania i izolacji plumbaginy i ramentacenu z matrycy analitycznej, którą stanowią chloroformowe ekstrakty z roślin D.aliciae i D.capensis z wykorzystaiem techniki NP-HPLC. Skład eluentu dla żelu krzemionkowego jako fazy stacjonarnej był optymalizowany. Zostały przedstawione optymalne warunki powiększania skali procesu izolacji badanych metabolitów z ekstrakrów roślinnych. Określono również...
-
Automatic music genre classification based on musical instrument track separation / Automatyczna klasyfikacja gatunku muzycznego wykorzystująca algorytm separacji dźwięku instrumentó muzycznych
PublicationThe aim of this article is to investigate whether separating music tracks at the pre-processing phase and extending feature vector by parameters related to the specific musical instruments that are characteristic for the given musical genre allow for efficient automatic musical genre classification in case of database containing thousands of music excerpts and a dozen of genres. Results of extensive experiments show that the approach...
-
Rapid and Green Separation of Mono- and Diesters of Monochloropropanediols by Ultrahigh Performance Supercritical Fluid Chromatography–Mass Spectrometry Using Neat Carbon Dioxide as a Mobile Phase
PublicationThis study demonstrates the effect of column selectivity and density of supercritical carbon dioxide (SC-CO2) on the separation of monochloropropanediol (MCPD) esters, known as food toxicants, using SC-CO2 without addition of cosolvent in ultrahigh performance supercritical fluid chromatography–mass spectrometry (UHPSFC-MS). This study shows that over 20 2-monochloropropanediol (2-MCPD) and 3-monochloropropanediol (3-MCPD) mono-...
-
Próbki wód spływnych - sposób pobierania z różnych powierzchni i ich skład chemiczny = Samples of runoff water - sampling procedures for different surfaces and chemical composition
PublicationPrzedstawiono dane dotyczące chemizmu wód spływnych dostających się do środowiska w wyniku zmywania przez opady atmosferyczne zanieczyszczeń z takich powierzchni jak: arterie komunikacyjne, dachy budynków, obszary rolnicze i leśne oraz hałdy odpadów. Wyniki uzyskane w trakcie badań własnych zestawiono z danymi literaturowymi. Informacje o metodyce pobierania próbek i położeniu stanowiska obserwacyjnego warunkują prawidłowy wynik...
-
Fermented Vinegars from Apple Peels, Raspberries, Rosehips, Lavender, Mint, and Rose Petals: The Composition, Antioxidant Power, and Genoprotective Abilities in Comparison to Acetic Macerates, Decoctions, and Tinctures
Publication -
Wpływ obwodnicy Trójmiasta na chemizm wód powierzchniowych niewielkich zagłębień bezodpływowych = The impact of the Gdańsk's ring road on the chemical composition of the surface waters in small outflowless pools
PublicationPrzedstawiono wyniki badań wpływu Obwodnicy Trójmiasta na chemizm wód niewielkich zbiorników bezodpływowych. Próbki poddano analizie na zawartość wybranych kationów i anionów oraz zbadano takie parametry jak pH oraz przewodnictwo. Uzyskane wyniki bardzo jasno wskazują na wysoki wpływ obwodnicy na skład i rodzaj zanieczyszczeń obecnych w badanych próbkach. Zaobserwowano m.in. alkalizację badanych wód oraz wysoki poziom stężeń takich...
-
Effect of Thermal Treatment of Birch Wood by Saturated Water Vapor on Granulometric Composition of Chips from Sawing and Milling Processes from the Point of View of Its Processing to Composites
PublicationThe goal of this work is to investigate the impact of thermal modification of birch wood with saturated steam on the particle size distribution of the sawing and milling process. Birch wood (Betula pendula Roth) is an excellent source to produce plywood boards. Wastes from mechanical processing of birch wood are suitable to produce composite materials. Granulometric analyses of chips from sawing processes on the PRW 15M frame saw,...
-
Analytical procedures for quality control of pharmaceuticals in terms of residual solvents content: Challenges and recent developments
PublicationResidual solvents play an important role in the synthesis of drugs and in product formulations. In addition, they pose a serious problem, that is toxicity, as many of them exhibit toxic or environmentally hazardous properties. Therefore, constant monitoring of quality control is needed. In this study, we present an overview of regulatory and general methods described by various pharmacopoeias. Then, the most commonly used methodologies...
-
Evaluation of the suitability of low hazard surfactants for the separation of phenols and carotenoids from red-flesh orange juice and olive mill wastewater using cloud point extraction
Publication -
Biogeochemistry of three different shallow gas systems in continental shelf sediments of the South-Eastern Baltic Sea (Gulf of Gdańsk): Carbon cycling, origin of methane and microbial community composition
Publication -
Effects of three-month feeding high-fat diets with different fatty acid composition on kidney histology and expression of genes related to cellular stress and water-electrolyte homeostasis in mice
Publication -
Comparative analysis of the quality parameters and the fatty acid composition of two economically important Baltic fish: cod, Gadus morhua and flounder, Platichthys flesus (Actinopterygii) subjected to iced storage
Publication -
La composition sur des lignes de fuite ou un équilibre manqué : le parti pris de l’espace dans les œuvres narratives d’Anna Langfus
Publication -
Large‐Scale Traveling Ionospheric Disturbances Over the European Sector During the Geomagnetic Storm on March 23–24, 2023: Energy Deposition in the Source Regions and the Propagation Characteristics
PublicationMultiple Large-Scale Traveling Ionospheric Disturbances (LSTIDs) are observed in the European sector in both day-time and night-time during the magnetic storm on March 23–24, 2023. The Total Electron Content (TEC) observation from a network of GNSS receivers shows the propagation of LSTIDs with amplitudes between around 0.5 and 1 TECU originating from auroral and polar cusp regions down to southern Europe (35°N) with velocities...
-
Synergistic effects of nitrogen-doped carbon and praseodymium oxide in electrochemical water splitting
PublicationHybrid materials featuring perovskite-type metal oxide in conjunction with heteroatom-doped graphene hold immense promise as alternatives to costly noble metal catalysts for electrochemical water splitting, facilitating the generation of environmentally friendly hydrogen. In this study, perovskite-type oxide containing praseodymium, barium, strontium, cobalt, and iron atoms dispersed in a carbon matrix as a catalyst is synthesized...
-
Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry
PublicationSolid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about...
-
Investigation of vortex assisted magnetic deep eutectic solvent based dispersive liquid–liquid microextraction for separation and determination of vanadium from water and food matrices: Multivariate analysis
PublicationA new and simple vortex assisted magnetic deep eutectic solvent dispersive liquid–liquid microextraction procedure (VA-MDES-DLLME) was developed for the determination of vanadium (V) in food and water samples by flame atomic absorption spectrometry (FAAS). In the extraction medium, a bis(acetylpivalylmethane) ethylenediimine (H2APM2en) was used for the complexation of V(V) in sample solution at pH 6. The VA-MDES-DLLME was optimized...
-
Skład zanieczyszczeń wprowadzanych do środowiska wzdłuż dróg o różnym natężeniu ruchu pojazdów mechanicznych = Composition of pollutants in the water samples collected along the highways with different traffic intensity
PublicationProwadzono monitoring poziomu stężeń wybranych zanieczyszczeń w próbkach wód opadowych, spływnych, gruntowych i rzecznych, pobieranych wzdłuż dróg o różnym natężeniu ruchu pojazdów. Zlokalizowano pięć stałych punktów pobierania próbek wzdłuż dwóch szlaków komunikacyjnych; drogi o małym natężeniu ruchu nr 501 w miejscowości Sztutowo oraz wzdłuż drogi krajowej nr A7 na odcinku Nowy Dwór Gdański - Elbląg. Próbki pobierano przez okres...
-
Rapid Characterization of the Human Breast Milk Lipidome Using a Solid-Phase Microextraction and Liquid Chromatography-Mass Spectrometry-Based Approach.
PublicationHuman breast milk (HBM) is a biofluid consisting of various biomolecules such as proteins, lipids, carbohydrates, minerals and bioactive substances. Due to its unique and complex composition, HBM provides not only nutritional components required for the growth of the infant, but also additional protection against infections. Global insight into the composition of HBM is crucial to understanding the health benefits infants receive...
-
Recent advances on magnetic carbon-related materials in advanced oxidation processes of emerging pollutants degradation
PublicationRecently, carbon-related materials have been proposed to improve the charge separation of the photogenerated carriers in the semiconductor matrices’ and surface properties. Carbon-related materials may act as co-catalysts, enhancing the pollutants adsorption on the surface, improving the charge carriers separation and photocatalyst stability and providing more active centres for photocatalytic reactions. This review summarizes...
-
Nowoczesne techniki przygotowania próbki do oznaczania analitów organicznych z zastosowaniem chromatografii gazowej. Część I. Podstawy teoretyczne ekstrakcji. Modern techniques of preparation of samples for determining organic analytes by gas chromatography. Part I. Theoretical principles of extraction.
PublicationPrzedstawiono podstawy teoretyczne technik izolacji i wzbogacania analitów organicznych z próbek gazowych oraz ciekłych. Już pobieżna analiza literatury dotyczącej omawianych zagadnień, pokazuje jak różnorodne i bogate spektrum technik jest stosowane na etapie przygotowania próbki. Z drugiej strony, z punktu widzenia podstaw fizykochemicznych, większość technik opiera się na dwóch zjawiskach: adsorpcji analitów na medium zatrzymującym...
-
Microstructure and electrical properties of manganese borosilicate glasses
PublicationThe structure, optical and electrical properties of manganese borosilicate glasses of the composition xMnO–(80 − x)SiO 2 –20B 2 O 3 (x = 40, 50, and 60 mol%) were investigated. The dependence of the glass structure on its composition was discussed and related to electrical properties. A separation of two amorphous phases was observed. It was suggested that one phase is MnO-rich and the other is SiO 2 -rich. It was found that...
-
Stopniowa chromatografia cienkowarstwowa w normalnych układach faz (NP-TLC), jako technika rozdzielania i oceny składu grupowego frakcji asfaltenowych z utleniania pozostałości próżniowej ropy naftowej
PublicationW pracy opisano wyniki badań nad opracowaniem metodyki oceny składu grupowego i czystości frakcji asfaltenowych techniką chromatografii cienkowarstwowej w normalnych układach faz (NP-TLC). Skupiono się na doborze takich parametrów/warunków rozdzielania, jak stężenie i masa próbki, a także skład i kolejność eluentów stosowanych podczas rozwijania chromatogramów TLC. Zastosowana trój-stopniowa metodyka polega na nałożeniu 5 µL frakcji...
-
The role of solvent solubility parameters in the formation of intermittent low and high molecular weight polystyrene rich structures in a thin film resulting from water vapor induced phase separation
Publication -
Improving web user experience with caching user interface
PublicationIn human-computer interaction, response time is assumed generally not to exceed significantly 1-2 seconds. While the natural competition in the Internet public Web serving ensures adhering widely to such limits, some Web environments are less competitive and offer much worse user experience in terms of response time. This paper describes a solution to significantly improve user experience in terms of response time with only modification...
-
The role of water in deep eutectic solvent-base extraction
PublicationDeep eutectic solvents (DESs) are currently being used in different sectors, such as electrochemistry, electrodeposition, organic synthesis, nanoparticle preparation, bioactive compound separation, etc. Their use in analytical chemistry has only recently begun to expand. Despite the publication of a sufficient number of DES-based analytical extraction procedures, some details, such as interaction of DESwith the sample and target...
-
Methods of assaying volatile oxygenated organic compounds in effluent samples by gas chromatography—A review
PublicationThe paper is a review of the procedures for the determination of volatile and semivolatile oxygenated organic compounds (O-VOCs) in effluent samples by gas chromatography. Current trends and outlook for individual steps of the procedure for the determination of O-VOCs in effluents are discussed. The available sample preparation techniques and their limitations are described along with GC capillary columns used for O-VOCs separation...
-
Usuwanie lotnych związków organicznych z fazy gazowej z zastosowaniem cieczy jonowych
PublicationUżycie cieczy jonowej do usuwania LZO jest limitowane przez rozpuszczalność usuwanych związków. Dane literaturowe sugerują, że ciecze jonowe jako faza membranowa mogą być z powodzeniem stosowane do selektywnej separacji węglowodorów aromatycznych z mieszanin węglowodorów aromatycznych i alifatycznych. Przedmiotem pracy było kompleksowe opisanie procesu separacji LZO z fazy gazowej z uwzględnieniem czynników wpływających na efektywność...
-
Immunoanalityka – użyteczne podejście analityczne w badaniach środowiska
PublicationWażnym krokiem w rozwoju bezpośrednich metodyk analitycznych było opracowanie technik immunoanalitycznych. Początkowo znalazły one zastosowanie praktyczne w analityce medycznej a później także w analityce środowiskowej. Dzięki temu możliwe jest ilościowe oznaczenie stosunkowo szerokiego spektrum ksenobiotyków w próbkach charakteryzujących się złożonym składem matrycy bez praco- i czasochłonnego etapu przygotowania tych próbek do...
-
Separation and determination of ciprofloxacin in seawater, human blood plasma and tablet samples using molecularly imprinted polymer pipette‐tip solid phase extraction and its optimization by response surface methodology
Publication -
Visible light photocatalysis employing TiO2/SrTiO3-BiOI composites: Surface properties and photoexcitation mechanism
PublicationA 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...
-
Pervaporation of volatile organohalogen compounds throughpolydimethylsiloxane membrane
PublicationThe objective of this work was to apply dense polymeric membranes for pervaporation of tetrachloroethene from aqueous solution. Three membranes were evaluated: polydimethylsiloxane (PDMS-PV1 and PDMSPV2) membranes, and a PDMS with ZSM-5 zeolite filled (PERVAP-1070) membrane. The effect of feed composition on flux and selectivity was also investigated. Tested membranes showed good properties in the separation of tetrachloroethylene,...