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Discrete Modelling of Micro-structural Phenomena in Granular Shear Zones
PublikacjaThe micro-structure evolution in shear zones in cohesionless sand for quasi-static problems was analyzed with a discrete element method (DEM). The passive sand failure for a very rought retaining wall undergoing horizontal translation towards the sand backfill was discussed. To simulate the behaviour of sand, the spherical discrete element model was used with elements in the form of rigid spheres with contacts moments.
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The PolarScreen™ Estrogen Receptor Competitor Assays for determination of estradiol equivalent concentrations (EEQs) in sewage and drinking water samples.
Dane BadawczeMunicipal waste waters are one of the main sources of estrogenic compounds in aquatic environments. Feminization of fish downstream of Waste Water Treatment Plants (WWTPs) discharges has been observed worldwide. Some estrogenic chemicals, particularly steroid estrogens, are known to cause disruption of the endocrine system of fishes and abnormalities...
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Electrical and structural properties of Nb-doped SrTiO3
PublikacjaNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
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Structure and electrical properties of Y, Fe-based perovskite mixed conducting composites fabricated by a modified polymer precursor method
PublikacjaIn this work, samples of Y0.07Sr0.93Ti1-xFexO3-d with 20, 40, 60 and 80 mol% of iron amount were prepared by a low-temperature polymer precursor method. The SEM-EDS analysis proved that analyzed Y0.07Sr0.93Ti1-xFexO3-d samples were composites of two Ti- and Fe-rich perovskite samples. This kind of composite consists of two phases in which one has a good ionic and the other electronic conductivity, which makes such a composite a...
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Rapid Evaluation of Poultry Meat Shelf Life Using PTR-MS
PublikacjaThe use of proton transfer reaction mass spectrometry (PTR-MS) for freshness classification of chicken and turkey meat samples was investigated. A number of volatile organic compounds (VOCs) were selected based on the correlation (> 95%) of their concentration during storage at 4 °C over a period of 5 days with the results of the microbial analysis. In order to verify if the selected compounds are not sample-specific, a number...
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Influence of grain shape on the mechanical behaviour of granular materials
PublikacjaWe performed series of numerical vertical compression tests on assemblies of 2D granular material using a Discrete Element code and studied the results in regard to the grain shape. The samples consist of 5000 grains made either of 3 overlapping discs (clump - grain with concavities) or of six-edged polygons (convex grain). These two types of grains have a similar external envelope, ruled with a geometrical parameter α. In the...
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Determination of short-chain monocarboksylic acids in cattle farm and dairy industry wastewater
PublikacjaThe paper describes application of various techniques to determine short-chain monocarboksylic acids (SCMAs) in samples from the successive steps from milk production: from wastewater from cattle farm to wastewater from dairy industry. Each technique of sample preparation is followed by gas chromatographic analysis.
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Can matrix solid phase dispersion (MSPD) be more simplified? Application of solventless MSPD sample preparation method for GC–MS and GC–FID analysis of plant essential oil components
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Wykorzystanie membran na etapie ekstrakcji analitów organicznychz ciekłych próbek środowiskowych i płynów biologicznych = Analytical applications of membrane extraction for liquid sample preparation in biomedical and environmental analysis
PublikacjaPrzedstawiono informacje dotyczące technik ekstrakcji membranowej wykorzystywanych do oznaczania związków organicznych w ciekłych próbkach środowiskowych i biologicznych. Szczególną uwagę zwrócono na podstawy teoretyczne oraz możliwości ich połączenia z technikami oznaczeń końcowych oraz obszarom praktycznego ich wykorzystania.
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Modern solutions in the field of microextraction using liquid as a medium of extraction
PublikacjaThe monitoring of compounds present in samples at trace/ultra-trace level usually requires a preliminary step of isolation and/or enrichment of analytes. Against, sample preparation is considered as crucial part of whole analytical procedures, in particular in samples characterized by complex matrices composition. Several new miniaturized extraction techniques is introduced and extensively applied to different type of samples....
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Determination of thiocyanate as a biomarker of tobacco smoke constituents in selected biological materials of human origin
Publikacjan order to protect human health, it is necessary to biomonitor toxic substances originating from tobacco smoke in biological materials sampled from persons with different exposures to tobacco smoke constituents. Thiocyanate anion is a biomarker of exposure to tobacco smoke components which is characterized by a relatively long half‐life in the human body, i.e. 6 days. In this work, we present the results of thiocyanate determinations...
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Current trends in the field of steganalysis and guidelines for constructions of new steganalysis schemes
PublikacjaThe paper concerns blind steganalysis techniques in the passive steganalysis scenario designed to detect the steganographic cover modification schemes. The goal is to investigate the state-of-art in the field of steganalysis, and, above all, to recognize current trends existing in this field and determine guidelines for constructions of new steganalysis schemes. The intended effects are to examine the possibilities for the development...
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Determination of Earth Pressure and Displacement of the Retaining Structure According to the Eurocode 7-1
PublikacjaComparative analysis of standard guidelines and findings given in EC7-1 and in Polish Standard PN-83/B-03010. Discussed guidelines concerning active and passive earth pressure as well as at rest pressure state. Wall displacement causing limit states of earth pressure and resistance. Interactive assumptions concerning intermediate earth pressure and resistance values. Conclusions and final remarks.
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Wojciech Wojnowski dr inż.
OsobyUkończył V Liceum Ogólnokształcące w Gdańsku w klasie o profilu matematyczno-fizycznym z wykładowym językiem angielskim. W 2009 roku rozpoczął studia na Wydziale Chemicznym PG na kierunku technologia chemiczna, uzyskując w 2012 roku tytuł inżyniera, a w 2013 tytuł magistra. W latach 2013–2015 studiował sinologię na Uniwersytecie w Nankinie dzięki uzyskaniu Stypendium Rządu ChRL. Po powrocie do Polski w 2015 roku rozpoczął studia...
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Consumer Bankruptcy Prediction Using Balanced and Imbalanced Data
PublikacjaThis paper examines the usefulness of logit regression in forecasting the consumer bankruptcy of households using an imbalanced dataset. The research on consumer bankruptcy prediction is of paramount importance as it aims to build statistical models that can identify consumers in a difficult financial situation that may lead to consumer bankruptcy. In the face of the current global pandemic crisis, the future of household finances...
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Correlations between the wear of car brake friction materials and airborne wear particle emissions
PublikacjaAirborne wear particles emitted from transport vehicle brakes are one of the main sources of toxic metals in inhalable particulate matter. Prediction of wear particle emissions may become more accurate if the relationship between the wear and particle emission characteristics is known. An experimental study was performed to investigate proportional correlations between the mass wear, 0.01–0.42 μm particle emission measured by a NanoScan...
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BTEX concentration levels in urban air in the area of the Tri-City agglomeration (Gdansk, Gdynia, Sopot), Poland
PublikacjaThe paper presents and discusses the results of atmospheric air quality research conducted in 2012 with reference to the level of BTEX compounds in the Tri-City agglomeration—Gdansk, Gdynia, and Sopot (northern Poland). At the stage of BTEX sampling from the ambient air, Radiello® diffusive passive samplers were applied. The annual time-weighted average concentrations for benzene, toluene, ethylbenzene, and xylenes (BTEX) in the...
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An adaptive approach to non-destructive evaluation (NDE) of cast irons containing precipitated graphite particles with the help of magnetoacoustic emission
PublikacjaPhysical properties of cast irons strongly depend on both their microstructure and the presence of casting defects. The paper analyses the possibility of application of magnetoacoustic emission (MAE) for nondestructive detection of flawed cast iron components. The investigated samples containing dross, chunky graphite and lamellar graphite were compared with the reference, flawless, spheroidal cast iron sample. The optimisation...
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EXAMINATION OF SOL-GEL DERIVED HYDROXYAPATITE ENHANCED WITH SILVER NANOPARTICLES USING OCT AND RAMAN SPECTROSCOPY
PublikacjaHydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements...
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Transformational Leadership and Acceptance of Mistakes as a Source of Learning: Poland-USA Cross-Country Study
PublikacjaThis study explores the influence of transformational leadership on internal innovativeness mediated by mistakes acceptance, including country and industry as factors to be considered and gender and risk-taking attitude as moderators. General findings, primarily based on the US samples (healthcare, construction, and IT industry), confirmed that transformational leadership and internal innovativeness are mediated by mistakes acceptance...
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Intergranular Corrosion Detection Using Electromagnetic Transducers for Ultrasonic Testing
PublikacjaThe aim of this paper is to create a research methodology that allows a quick analysis of the structural state of high alloy austenitic steels using non-destructive ultrasonic tests, in contrast to destructive standard methods. Electromagnetic acoustic transducers (EMAT) are used to generate and receive the ultrasonic wave and detect the microstructural changes caused by sample sensitization in elevated temperature, even after...
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Badania eksperymentalne strefy przypodporowej żelbetowych belek częściowo sprężonych
PublikacjaThis project refers to the study the shear zone, under full and partial prestressing in comparison to beams with passive reinforcement.For comparison, variable parameters have been determined:- a/d (from 1,5 to 3,5) - it's shear span to effective depth of the beam . Assuming constant geometrical quantities, "a" is variable.- 26 beams had no vertical shear reinforcement, and the other 26 had closed stirrups.- prestressing intensity...
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SURFACTANTS IN KLODNICA RIVER (KATOWICE, POLAND). PART II. QUATERNARY AMMONIUM COMPOUNDS
PublikacjaThe paper presents methods of determination of analytes of the cation group (alkyl benzyl dimethyl ammonium (BDDA-C12-C16), alkyl trimethyl ammonium (TMA), hexadecyl piridinium (HP)) in surface water and bottom sediment samples. In the sample preparation phase the solid phase extraction (SPE) or accelerated solvent extraction/ultrasound assisted extraction (ASE/UAE)-SPE technique was used and in the identification phase and quantitative...
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Study of the Effectiveness of Model Order Reduction Algorithms in the Finite Element Method Analysis of Multi-port Microwave Structures
PublikacjaThe purpose of this paper is to investigate the effectiveness of model order reduction algorithms in finite element method analysis of multi-port microwave structures. Consideration is given to state of the art algorithms, i.e. compact reduced-basis method (CRBM), second-order Arnoldi method for passive-order reduction (SAPOR), reduced-basis methods (RBM) and subspace-splitting moment-matching MOR (SSMM-MOR)
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ON ESTIMATION OF OCCUPANT SAFETY IN VEHICULAR CRASHES INTO ROADSIDE OBSTACLES USING NON-LINEAR DYNAMIC ANALYSIS
PublikacjaThe article describes a comparison of two general methods of occupants safety estimation based on a numerical examples. The so-called direct method is mainly based on the Head Injury Criterion of a crash test dummy in a vehicle with passive safety system while the indirect method uses a European standards approach to estimate impact severity level. Numerical simulations in LS-DYNA have been conducted.
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Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry
PublikacjaSolid 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...
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Thermo-Mechanical Simulation of Underwater Friction Stir Welding of Low Carbon Steel
PublikacjaThis article investigates the flow of materials and weld formation during underwater friction stir welding (UFSW) of low carbon steel. A thermo-mechanical model is used to understand the relation between frictional heat phenomena during the welding and weld properties. To better understand the effects of the water environment, the simulation and experimental results were compared with the sample prepared by the traditional friction...
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Determination of volatile fatty acids in municipal wastewater and leachates from sewage sludge allotments and compost piles using direct aqueous injection gas chromatography preceded by distillation based sample cleanup
PublikacjaOpracowano metodykę i wykorzystano ją do oznaczania lotnych kwasów tłuszczowych w zanieczyszczonych próbkach wodnych,takich jak ścieki komunalne, odcieki ze składowiska osadów ściekowych i pryzm kompostu, stosując metodę bezpośredniego dozowania rzeczywistej próbki wodnej lub jej rektyfikatu do chromatografu gazowego.
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Diagnostic Accuracy of Liquid Biopsy in Endometrial Cancer
PublikacjaBackground: Liquid biopsy is a minimally invasive collection of a patient body fluid sample. In oncology, they offer several advantages compared to traditional tissue biopsies. However, the potential of this method in endometrial cancer (EC) remains poorly explored. We studied the utility of tumor educated platelets (TEPs) and circulating tumor DNA (ctDNA) for preoperative EC diagnosis, including histology determination. Methods:...
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Split-Beam Echosounder Data from Puck Bay
PublikacjaThe acoustic data was collected in 2018–2019 in the Bay of Puck in the seasons: autumn, winter, spring. The data was collected during the day and night using three split-beam echosounders with frequencies of 38 kHz, 120 kHz and 333 kHz at a designated study area not far from the city of Hel, while the ship was sailing. To ensure data quality, the echosounders were calibrated and passive noise was measured.
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Control System Design for Dynamic Positioning using Vectorial Backstepping
PublikacjaThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. The computer simulation results were given to...
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Comparative modeling of shear localization in granular bodies with FEM and DEM
PublikacjaThe intention of the paper is to compare the calculations of shear zones in granular bodies using two different approaches: a continuum and a discrete one. In the first case, the FEM based on a micro-polar hypoplastic constitutive law was used. In the second case, the DEM was taken advantage of, where contact moments were taken into account to model grain roughness. The comparative calculations were performed for a passive case...
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Weldability of pipe grade polyethylenes as realized from thermal and mechanical properties assessments
PublikacjaSince polyethylene (PE) has been widely accepted for the production of high-pressure fluid conveying pipelines, studies devoted to weldability of PE connections were always of major importance. In this study, two industrial PE grades designed for pipe production, namely PE80 and PE100, were injection molded, cut, and then welded as PE100-PE100, PE100-PE80, and PE80-PE80. The heat-welded joints were assessed by differential scanning...
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DYNAMIC ANALYSIS OF HISTORIC RAILWAY BRIDGES IN POLAND IN THE CONTEXT OF ADJUSTING THEM TO PENDOLINO TRAINS
PublikacjaThe article presents the dynamic analysis of the historic railway bridge in Tczew as an example of the usefulness of such type of bridge for high-speed trains. The model of the bridge and the simulation of rolling stock passage was performed in SOFISTIK program. The scope of work includes experimental studies, the solution of the problem concerning the correct solution features dynamic model takes into account the dependencies...
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Deep eutectic solvent (DES) with silver nanoparticles (Ag-NPs) based assay for analysis of lead (II) in edible oils
PublikacjaThis paper presents an application of silver nanoparticles impregnated by Deep Eutectic Solvents (DES) as ultrasonication aided microextraction system for lead (II) determination in edible oils. The paper presents a systematic optimization of method parameters and examples of its application for analysis of real samples. Maximum recovery for lead (II) extraction was obtained for choline chloride and phenol with a 1:2 molar ratio....
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System for automatic singing voice recognition
PublikacjaW artykule przedstawiono system automatycznego rozpoznawania jakości i typu głosu śpiewaczego. Przedstawiono bazę danych oraz zaimplementowane parametry. Algorytmem decyzyjnym jest algorytm sztucznych sieci neuronowych. Wytrenowany system decyzyjny osiąga skuteczność ok. 90% w obydwu kategoriach rozpoznawania. Dodatkowo wykazano przy pomocy metod statystycznych, że wyniki działania systemu automatycznej oceny jakości technicznej...
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Design and simulation of a new prototype of piezoelectric cantilever sensor/actuator for analysis of the soft tissues properties
PublikacjaThis paper is devoted to a new prototype of piezoelectric cantilever transducer dedicated for the characterization of the mechanical properties of soft tissues. General description of the actuator’s structure is presented including the basic principles of the measurement. The chosen geometry of the prototype is discussed and compared with the existing one. Constitutive equations are presented for the active and passive layer of...
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A new prototype of piezoelectric bending resonant transducer for analysis of soft tissues properties
PublikacjaThis paper is devoted to a new piezoelectric bending resonant transducer prototype dedicated to the characterization of the mechanical properties of soft tissue. A general description of the actuator’s structure is presented including the basic principles of the measurement. The chosen geometry of the prototype is discussed and compared with the existing version. Constitutive equations are presented for the active and passive layer...
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CV (cyclic voltammetry) curves of the CPMD sample at different scan rates
Dane BadawczeThese data contain CV curves of CPMD obtained at a scan rate from 1 mV s−1 to 20 mV s−1. Sample abbreviations (CPMD) are in agreement with the markings used in the linked publication.
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Maximum forces in tendon connections for an anchor with a pin in the full sample experiment
Dane BadawczeThe main objective of the all study was to assess the load capacity of a new implant device for knotless tendon anastomosis. During this series of experiments the load capacity of the anchoring element with a pin (see figure 1) was examined. Tendons from fresh swine legs (commercially available) served as the biological material. All samples were subjected...
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Potentiometric Solid-Contact Multisensor System for Simultaneous Measurement of Several Ions
PublikacjaThe design and performance of potentiometric multisensor system made in solid-contact technology is described. Both, the measuring electrodes as well as the reference electrode are in a compact cell. The system allows for simultaneous measurement of various ions. The characteristics of the electrodes for Na+, K+ and Ca2+ ions were determined using the designed system and compared with ISEs of the same membrane composition in classical...
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Influence of terpenes on indoor air quality
PublikacjaThe aim of this study was to investigate air quality in hairdresser salons, focusing on terpenes determination. Terpenes are known reactive volatile organic compounds that contribute to secondary organic aerosol formation. Those compounds are frequently found in cosmetic products as fragrance agents. Hairdresser salons are special kind of environment, where secondary organic aerosol concentration may be elevated. One hairdresser...
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Isolation of the relative decrease in magnetic permeability contribution to reluctance of an open magnetic circuit based on stray field measurements
PublikacjaThe goal of the study was to evaluate a relative decrease in magnetic permeability in open magnetic circuits based on stray magnetic field measurements. The boundary element method was used to simulate magnetic circuits with variable geometry and variable magnetic permeability. The simulated magnetic circuits were rectangular or bone-shaped flat samples. Reluctance was increased in the middle of the samples resulting in leakage...
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imPlatelet classifier: image‐converted RNA biomarker profiles enable blood‐based cancer diagnostics
PublikacjaLiquid biopsies offer a minimally invasive sample collection, outperforming traditional biopsies employed for cancer evaluation. The widely used material is blood, which is the source of tumor-educated platelets. Here, we developed the imPlatelet classifier, which converts RNA-sequenced platelet data into images in which each pixel corresponds to the expression level of a certain gene. Biological knowledge from the Kyoto Encyclopedia...
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Classifying type of vehicles on the basis of data extracted from audio signal characteristics
PublikacjaThe aim of this study is to find and optimize a feature vector for an automatic recognition of the type of vehicles, extracted form an audio signal. First, the influence of weather-based conditions of road surface on spectral characteristic of the audio signal recorded from a passing vehicle in close proximity to the road is discussed. Next, parameterization of the recorded audio signal is performed. For that purpose, the MIRtoolbox,...
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Zanieczyszczenie obecne w próbkach śniegu pobranego z warstw jako źródło informacji o stanie środowiska w dużej aglomeracji miejskiej = Pollutants present in snow samples collected from various layers of snow cover as a source of information about the state of environment in a big urban agglomeration
PublikacjaPróbki śniegu pobierano przez okres około miesiąca z 12 miejsc zlokalizowanych na terenie Trójmiasta. Sześć z nich znajdowało się w pobliżu dróg komunikacyjnych o różnym natężeniu ruchu. Każde z nich miało swój punkt odniesienia oddalony od niego o około 200 m. W próbkach śniegu oznaczano pH, przewodność, zawartość wybranych anionów i kationów. Wartości pH wyznaczono przy użyciu elektrody szklanej połączonej z pH/tlenomierzem mikrokomputerowym,...
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Bacterial Community Structures in Freshwater Polar Environments of Svalbard
PublikacjaTwo thirds of Svalbard archipelago islands in the High Arctic are permanently covered with glacial ice and snow. Polar bacterial communities in the southern part of Svalbard were characterized using an amplicon sequencing approach. A total of 52,928 pyrosequencing reads were analyzed in order to reveal bacterial community structures in stream and lake surface water samples from the Fuglebekken and Revvatnet...
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Overall color parameter as a parameter determining the level of oxidation of olive oil
PublikacjaEdible fats are an important part of a human daily diet. They have a significant effect on the proper functioning of the human body. During frying, the oil is chemically modified and the fats consumed should have the highest oxidation stability. The subject of the study were samples of olive oil bought at local markets in Gdansk. Samples were heated at 20 °C, 60 °C, 100 °C, 140 °C and 180 °C. The aim of the study was to determine...
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Global and regional economic inequality: Methods of measurement and evidences
PublikacjaThe lack of countries’ statistical income data, comparable across countries and years, seems to be the main reason of controversial conjectures concerning global inequality and its evolution over time. In the databases, which purport to collect income data on a worldwide scale, only some summary statistics (quantile income shares, means, Gini indices) are presented. Therefore, the development of efficient methods of extracting...
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Prediction of the Biogenic Amines Index of Poultry Meat Using an Electronic Nose
PublikacjaThe biogenic amines index of fresh chicken meat samples during refrigerated storage was predicted based on the headspace analysis using an electronic nose equipped with an array of electrochemical sensors. The reference biogenic amines index values were obtained using dispersive liquid–liquid microextraction–gas chromatography–mass spectrometry. A prototype electronic nose with modular construction and a dedicated sample chamber...