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Wyniki wyszukiwania dla: SIZE-EXCLUSION CHROMATOGRAPHY
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Grain type and size of particulate matter from diesel vehicle exhausts analysed in transmission electron microscopy
PublikacjaThe aim of this research was to apply a simple and quick method of size and shape characterization by TEM to diesel exhaust particles from large-capacity, high-performance trucks. Particulate matter (PM) samples were collected while the engines were idling. It was found that PM from vehicle exhaust emissions can be divided into three groups: soot, irregular-shaped particles and circular particles. Irregular-shaped particles and...
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Novel analytical method for detection of orange juice adulteration based on ultra-fast gas chromatography
PublikacjaThe food authenticity assessment is an increasingly important issue in food quality and safety. The application of an electronic nose based on ultra-fast gas chromatography technique enables rapid analysis of the volatile compounds from food samples. Due to the fact that this technique provides chemical profiling of natural products, it can be a powerful tool for authentication in combination with chemometrics. In this article,...
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On some problems in determining tensile parameters of concrete model from size effect tests
PublikacjaThe paper presents results of numerical simulations of size effect phenomenon in concrete specimens. The behaviour of in-plane geometrically similar notched and unnotched beams under three-point bending is investigated. In total 18 beams are analysed. Concrete beams of four different sizes and five different notch to depth ratios are simulated. Two methods are applied to describe cracks. First, an elasto-plastic constitutive law...
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Development of a compact microstrip resonant cell aimed at efficient microwave component size reduction
PublikacjaA comprehensive comparison of a wide collection of compact microstrip resonant cells (CMRCs) found in the extensive body of literature has been presented. The evaluation of different CMRC designs has led to the selection of the most promising CMRC geometry for the efficient miniaturisation of modern microwave components. In order to showcase the vital effectiveness of the approach, the initially selected CMRC has been notably...
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A framework estimating the minimum sample size and margin of error for maritime quantitative risk analysis
PublikacjaThe average accident frequency is essential for quantitative risk analysis and is conventionally estimated from accident statistics. This paper has systematically synthesised the knowledge on statistical errors and offered the missing instructions, a framework, for determining the minimum sample size and the margin of error (MOE) when calculating the average accident frequency from an accident database at hand. We have applied...
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Molecular mechanism of retention in reversed-phase high-performance liquid chromatography and classification of modern stationary phases by using quantitative structure–retention relationships
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Calibration of the thermal desorption-gas chromatography-mass spectrometry system using standards generated in the process of thermal decomposition of chemically modified silica gel
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Least absolute shrinkage and selection operator and dimensionality reduction techniques in quantitative structure retention relationship modeling of retention in hydrophilic interaction liquid chromatography
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Simultaneous determination of hydrophobicity and dissociation constant for a large set of compounds by gradient reverse phase high performance liquid chromatography–mass spectrometry technique
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Water retention curves of sandy soils obtained from direct measurements, particle size distribution, and infiltration experiments
PublikacjaAccurate information about soil water retention curves (SWRCs) of sands is essential for evaluating groundwater recharge and vulnerability to contamination in many shallow sandy aquifers which are widespread on post glacial areas in Northern Europe and North America. Pedotransfer functions (PTFs) allow to estimate SWRC from basic physical characteristics of soils, such as textural composition. However, in the case of clean sands...
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INFLUENCE OF DREDGER POWER PLANT TYPE AND DREDGER SIZE ON OUTPUT OF POWER PLANT INSTALLED ON TRAILING SUCTION HOPPER DREDGER
PublikacjaThis paper presents results of investigations dealing with influence of parameters characterizing size of suction hopper dredger as well as type of power system on magnitude of total output of combustion engines installed in dredger power plant.
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The structure of the enterprise sector by size in Poland and the EU-28 in 2017
Dane BadawczeEnterprises from the SME sector constitute the majority of companies in Poland and in the European Union countries. However, the structure of domestic enterprises in terms of size and industry differs from the EU average. Taking into account the nature of the business in Poland, more companies operate in trade, and lower in services. However, it should...
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Powder metallurgy of the porous Ti-13Nb-13Zr alloy of different powder grain size
PublikacjaThe objective of the present project was to determine the effects of powder granulation (fraction of grain size) for the Ti-13Nb-13Zr alloy, produced by powder metallurgy, on its porosity, grain cohesion, compressive strength, and Young`s modulus. Two powder fractions, 45–105 µm, and 106–250 µm were applied. The 50 mass pct of NH4HCO3 was added as a space holder. The specimens were in compaction stage uniaxially pressed at pressure...
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Novel liquid chromatography method based on linear weighted regression for the fast determination of isoprostane isomers in plasma samples using sensitive tandem mass spectrometry detection
PublikacjaA simple, fast, sensitive and accurate methodology based on a LLE followed by liquid chromatography–tandem mass spectrometry for simultaneous determination of four regioisomers (8-iso prostaglandin F2α, 8-iso-15(R)-prostaglandin F2α, 11β-prostaglandin F2α, 15(R)-prostaglandin F2α) in routine analysis of human plasma samples was developed. Isoprostanes are stable products of arachidonic acid peroxidation and are regarded as the...
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The clamping selection method to reduce the vibration of large-size workpieces during the face milling process
PublikacjaThe article introduces a method for selecting the best clamping conditions to obtain vibration reduction during milling of large-size workpiece. It is based on experimental modal analysis performed for a set of assumed, fixing conditions of a considered workpiece to identify Frequency Response Functions (FRFs) for each tightening torque of the mounting screws. Simulated plots of periodically changing nominal cutting forces are...
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The impact of carbon black particle size on curing characteristics of GTR modified with bitumen
Dane BadawczePresented data shows an impact of particle size of GTR and three different loadings of carbon black on curing characteristics of GTR modified with bitumen. Samples were prepared using a two-roll mill – all in the same manner. After 24 hours of stabilization at ambient conditions they were submitted to the curing analysis via Rheometer Monsanto 100S....
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Carrot root size distribution in response to biostimulant application
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Country selection strategies based on value, size and momentum
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Broadband Microstrip Patch Antenna with Reduced Transversal Size
PublikacjaW pracy przedstawiono propozycję anteny szerokopasmowej o ograniczonych wymiarach poprzecznych. Szerokopasmowość uzyskano poprzez stosowanie grubego podłoża i sprzężenia elektromagnetycznego poprzez dwie szczeliny sprzęgające. Wymiar poprzeczny łaty zredukowano poprzez zastosowanie szczeliny typu H. Antena została zaprojektowana i wykonana, zaś zmierzone pasmo wyniosło 29% dla WFS <1.5. Stwierdzono jednak, że charakterystyki...
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Multi-Criteria Optimization for Fleet Size with Environmental Aspects
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Floe-size distributions in laboratory ice broken by waves
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Floe-size distributions in laboratory ice broken by waves
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Floe-size distributions in laboratory ice broken by waves
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Floe-size distributions in laboratory ice broken by waves
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Influence on micrograins size on the distance between the workpiece and the lap.
PublikacjaNa kształtowanie powierzchni docieranej główny wpływ ma błąd kształtu zastosowanego narzędzia. Intensywność docierania zależy od wielkości zastosowanych ziaren ściernych, które również wpływają na błędy kształtu przedmiotu. W referacie przedstawiono wyniki obliczeń odległości przedmiotu od powierzchni narzędzia w funkcji wielkości ziaren ściernych.
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Oil refinery dusts: morphological and size analysis by TEM
PublikacjaThe objectives of this work were to develop a means of sampling atmospheric dusts on the premises of an oil refinery for electron microscopic study to carry out preliminary morphological analyses and to compare these dusts with those collected at sites beyond the refinery limits. Carbon and collodion membranes were used as asupport for collection of dust particles straight on transmission electron microscopy (TEM) grids. Micrographs...
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Size Reduction of Microwave Couplers by EM-Driven Optimization
PublikacjaThis work addresses simulation-driven design optimization of compact microwave couplers that explicitly aims at circuit footprint area reduction. The penalty function approach allows us to minimize the area of the circuit while ensuring a proper power division between the output ports and providing a sufficient bandwidth with respect to return loss and isolation around the operating frequency. Computational cost of the optimization...
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Universal construction of genuinely entangled subspaces of any size
PublikacjaWe put forward a simple construction of genuinely entangled subspaces – subspaces supporting only genuinely multipartite entangled states – of any permissible dimensionality for any number of parties and local dimensions. The method uses nonorthogonal product bases, which are built from totally nonsingular matrices with a certain structure. We give an explicit basis for the constructed subspaces. An immediate consequence of our...
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Thermal degradation assessment of canola and olive oil using ultra-fast gas chromatography coupled with chemometrics
PublikacjaOil blending is often used to enhance the properties of vegetable oils. The admixture of a more thermally stable oil makes the resulting blend more suitable for use in frying. A new method of quality assessment of vegetable oils used in frying is presented in this paper. In this method, ultra-fast gas chromatography coupled with flame ionization detector and chemometrics is employed. Principal component analysis was used for data...
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Pore size distribution of PC-X (porous carbon materials obtained at various temperatures)
Dane BadawczeThese data contain pore size distribution of PC-700 (porous carbon materials obtained at 700°C), PC-800 (porous carbon materials obtained at 800°C) and PC-900 (porous carbon materials obtained at 900°C) analyzed by the nitrogen adsorption/desorption technique.
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Dagmara Nikulin dr
OsobyDagmara Nikulin jest zatrudniona na Wydziale Zarządzania i Ekonomii na stanowisku adiunkta badawczo-dydaktycznego od 2014 roku. Początkowo pracowała w Katedrze Nauk Ekonomicznych, a obecnie w Katedrze Statystyki i Ekonometrii. Jest absolwentką Wydziału Ekonomii Uniwersytetu Ekonomicznego w Poznaniu (2009) oraz Wydziału Nauk Społecznych Uniwersytetu im. Adama Mickiewicza w Poznaniu (2010). W latach 2006-2007 studiowała na uniwersytecie...
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Estimation of object size in the calibrated camera image = Estymacja rozmiaru obiektów w obrazach ze skalibrowanej kamery
PublikacjaIn the paper, a method of estimation of the physical sizes of the objects tracked by the camera is presented. First, the camera is calibrated, then the proposed algorithm is used to estimate the real width and height of the tracked moving objects. The results of size estimation are then used for classification of the moving objects. Two methods of camera calibration are compared, test results are presented and discussed. The proposed...
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FE analysis of a coupled energetic-statistical size effect in plain concrete beams with varying material properties.
PublikacjaThe numerical FE investigations of a coupled energetic-statistical size effect in unnotched concrete beams of similar geometry under quasi-static three point bending were performed within elasto-plasticity with non-local softening. The stochastic FE analyses were carried out with three different beam sizes. Deterministic calculations were performed with the uniform distribution of a uniaxial tensile strength. In statistical calculations...
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Study of pH and temperature effect on lipophilicity of catechol-containing antioxidants by reversed phase liquid chromatography
PublikacjaLipophilicity of selected antioxidant phytochemicals, including flavonoids, phenolic acids and xanthonoids, was determined by reversed phase high performance liquid chromatography with UV detection (RP-HPLC-UV). The analyses run at different temperature and pH conditions in isocratic mode suggested that lipophilicity as distribution coefficient (logD) between aqueous and organic phase decreases with increasing temperature. For...
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A new silylating reagent – dimethyl(3,3,3-trifluoropropyl)silyldiethylamine – for the derivatisation of non-steroidal anti-inflammatory drugs prior to gas chromatography–mass spectrometry analysis
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Using pattern recognition entropy to select mass chromatograms to prepare total ion current chromatograms from raw liquid chromatography–mass spectrometry data
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Investigation of Wood Flour Size, Aspect Ratios, and Injection Molding Temperature on Mechanical Properties of Wood Flour/Polyethylene Composites
PublikacjaIn the present research, wood flour reinforced polyethylene polymer composites with a coupling agent were prepared by injection molding. The effects of wood flour size, aspect ratios, and mold injection temperature on the composites’ mechanical properties were investigated. For the preparation of the polymer composites, five different formulations were created. The mechanical properties including tensile strength and the modulus,...
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Size effect in concrete beams under bending – influence of the boundary layer and the numerical description of cracks
PublikacjaIn the paper the size effect phenomenon in concrete is analysed. The results of numerical simulations of using FEM on geometrically similar un-notched and notched concrete beams under bending are presented. Concrete beams of four different sizes and five different notch heights under three-point bending test were simulated. In total 18 beams were analysed. Two approaches were used to describe cracks in concrete. First, eXtended...
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Gas chromatography-olfactometry (GC-O), electronic noses (e-noses) and electronic tongues (e-tongues) for in vivo food flavour measurement
PublikacjaThe capter revies two types of artificial olfaction instrumentation, i.e. gas-chromatography-olfactometry (GC-O) and chemical sensor technologies (electronic nose and tongue), combined with multivariate data processing methods as promising approaches for rapid analysis of food. The chapter also includes examples of specific applications for the detection of food flavour and volatile components.
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Explicit Size-Reduction-Oriented Design of a Compact Microstrip Rat-Race Coupler Using Surrogate-Based Optimization Methods
PublikacjaIn this paper, an explicit size reduction of a compact rat-race coupler implemented in a microstrip technology is considered. The coupler circuit features a simple topology with a densely arranged layout that exploits a combination of high- and low-impedance transmission line sections. All relevant dimensions of the structure are simultaneously optimized in order to explicitly reduce the coupler size while maintaining equal power...
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A method of predicting the best conditions for large-size workpiece clamping to reduce vibration in the face milling process
PublikacjaThe paper presents an innovative method of solving the problem of vibration suppression during milling of large-size details. It consists in searching for the best conditions for clamping the workpiece based on a rapid modal identification of the dominant natural frequencies only and requires repetitive changes in the tightening torque of the clamping screws. Then, by estimating the minimum work of the cutting forces acting in...
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Authenticity Assessment of the "Onisiówka" Nalewka Liqueurs Using Two-Dimensional Gas Chromatography and Sensory Evaluation
PublikacjaThe “Onisiówka” nalewka liqueur is a regional Polish alcoholic beverage, which is inscribed on the list of regional and traditional products of the Ministry of Agriculture and Rural Development in Poland. It is produced from multiflower honey, black elderberry flower syrup, and spirit. Due to fact that the “Onisiówka” nalewka liqueur has never been investigated, these studies are the foundation for further work on this regional...
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Application of gas chromatography–tandem mass spectrometry for the determination of amphetamine-type stimulants in blood and urine
PublikacjaAmphetamine, methamphetamine, phentermine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxy-N-ethylamphetamine (MDEA) are the most popular amphetamine-type stimulants. The use of these substances is a serious societal problem worldwide. In this study, a method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) with simple and rapid liquid-liquid extraction (LLE)...
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The size of enterprises in which graduates of the Gdańsk University of Technology work – years 2010-2018
Dane BadawczeThe dataset includes data from the survey on the Gdańsk University of Technology graduates from years 2010-2018 on the size of enterprises in which they work. The survey was conducted in the period from 2012 to 2020, two years after the respondents obtained graduate status. The research sample included 12776 respondents. To summarize, the Gdańsk University...
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Long-Term Impact of Wind Erosion on the Particle Size Distribution of Soils in the Eastern Part of the European Union
PublikacjaWind erosion is the leading cause of soil degradation and air pollution in many regionsof the world. As wind erosion is controlled by climatic factors, research on this phenomenon isurgently needed in soil and land management in order to better adapt to climate change. In thispaper, the impact of wind erosion on the soil surface in relation to particle size distribution wasinvestigated. Changes in percentage of sand, silt and...
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Rapid Characterization of the Human Breast Milk Lipidome Using a Solid-Phase Microextraction and Liquid Chromatography-Mass Spectrometry-Based Approach.
PublikacjaHuman 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...
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Patch size setup and performance/cost trade-offs in multi-objective antenna optimization using domain patching technique
PublikacjaA numerical study concerning multi-objective optimization of antenna structures using sequential domain patching (SDP) technique has been presented. We investigate the effect of various setups of the patch size on the operation of the SDP algorithm and possible trade-offs concerning the quality of the Pareto set found by SDP and the computational cost of the optimization process. Our considerations are illustrated using a UWB monopole...
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Rapid determination of multiple aminoglycoside antibiotics in veterinary formulations by ion-pair chromatography coupled with evaporative light scattering detection
PublikacjaA fast and simple method for simultaneous determination of eight aminoglycoside antibiotics using ion-pairing liquid chromatography (IPLC) coupled with evaporative light scattering detection (ELSD) has been developed and validated. Separation of amikacin, apramycin, gentamicin (as a sum of gentamicin C1, C2 and C1A), kanamycin A, neomycin B, paromomycin, streptomycin and tobramycin was achieved using C18 column with H2O and MeOH/acetone,...
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Calixarenes as stationary phases in High Performance Liquid Chromatography
PublikacjaPraca przeglądowa przedstawia dotychczasowe metody syntezy faz stacjonarnych na bazie pochodnych kaliksarenów, kaliksrezorcyarenów i kalikspiroli chemicznie ziązanych z żelem krzemionkowym lub dynamicznie na nim obsadzonych. Podsumowano zastosowanie tych faz w rozdzielaniu szeregu klas związków organicznych i nieorganicznych metodą wysokosprawnej chromatografii cieczowej.
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Identification of acrylate copolymers using pyrolysis and gas chromatography
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