Filtry
wszystkich: 1558
-
Katalog
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: PB ISOTOPIC RATIO
-
Bioaccumulation of Metals in Tissues of Marine Animals, Part I: the Role and Impact of Heavy Metals on Organisms
PublikacjaHeavy metals contribute to the anthropogenic contamination of marine ecosystems. Some of them are essential to the life processes of organisms; others are toxic, even at low concentrations. They penetrate organisms via food, respiratory pathways or the skin. The extent to which metals penetrate organisms is measured by the bioconcentration and bioaccumulation factors and also by their transport between organisms at different trophic...
-
Release of selected chemical elements from shale drill cuttings to aqueous solutions of different pH
PublikacjaThe effect of pH changes on leachability of light and heavy metals from shale drill cuttings generated from unconventional shale gas production was investigated. Cuttings, being the primary byproduct generated from drilling operations, belong to the potentially hazardous type of wastes due to presence of heavy and radioactive elements and remains of drilling fluid. In this regard, assessment of potentially dangerous components...
-
Svalbard reindeer as an indicator of ecosystem changes in the Arctic terrestrial ecosystem
PublikacjaOver the years, noticeable effort has been directed towards contaminant determination in multiple biotic samples collected from the inhabitants of the Arctic. Little consideration has been given to polar herbivores, however, especially those from the European parts of the Arctic. To provide a broader perspective, we aimed to decipher trace element concentration in hairs of the key species in the Arctic, namely the Svalbard reindeer...
-
Arctic catchment as a sensitive indicator of the environmental changes: distribution and migration of metals (Svalbard)
PublikacjaArctic regions experience metal pollution, despite their remote location, and the distribution and migration of those metals determine their potential impact on the local environment. Here, a High-Arctic catchment (Revelva, Svalbard) located remotely from human-induced pollution sources is studied with respect to the distribution and migration of chosen trace elements (Ag, Al, As, B, Ba, Bi, Ca, Cd, Co, Cr, Cu, Cs, Mo, Ni, Pb,...
-
Quality control of cheese samples for the presence of natamycin preservative – A natural deep eutectic solvent (NADES) based extraction coupled with HPLC
PublikacjaA new protocol for the determination of natamycin – an antifungal agent used as a food preservative - in cheese samples – is described. This new method is based on a natural deep eutectic solvent (NADES) green extraction procedure. High-performance liquid chromatography (HPLC) was used for detection and quantification. NADESs with different molar ratios were evaluated for efficient and selective extraction. NADES made of thymol...
-
Spatial variability of the hydrochemistry of shallow groundwaters and surface waters of the Rensdyrbekken: A case study of a permafrost catchment in Bellsund (SW Spitsbergen, Svalbard)
PublikacjaProgressive climate change may have unpredictable consequences for the Arctic environment. Permafrost catchments off the west coast of Svalbard, described as “thin” and “warm,” are particularly sensitive to climate change. The interdisciplinary research on the hydrochemical response of surface and underground water functioning within a small permafrost catchment area focused on the determination of the impact of meteorological...
-
Microbial and chemical quality assessment of the small rivers entering the South Baltic. Part I: Case study on the watercourses in the Baltic Sea catchment area
PublikacjaThe area of the Coastal Landscape Park (CLP) due to its location is extremely attractive touristic area. In the summer season, a significant increase in population density is observed, which influences surface water quality. Large numbers of tourists generate an increased amount of municipal wastewater, being treated in local treatment plants and discharged into rivers and streams. The paper presents preliminary research from summer...
-
OCENA PRZYDATNOŚCI WIELOWYMIAROWYCH MODELI DYSKRYMINACYJNYCH DO PROGNOZOWANIA UPADŁOŚCI PRZEDSIĘBIORSTW HANDLOWYCH
PublikacjaCelem badań była ocena przydatności użycia modeli opartych na wielowymiarowej analizie dyskryminacyjnej do prognozowania upadłości polskich przedsiębiorstw handlowych oraz próba zwiększenia ich sprawności poprzez zmianę wartości ich punktów granicznych. Badaniu poddano modele: E. I. Altmana „B”, D. Hadasik, A. Hołdy oraz M. Hamrola, B. Czajki i M. Piechockiego. Do oceny modeli wykorzystano iloraz szans oraz macierz klasyfikacji...
-
Konkurencyjność w handlu usługami wybranych krajów Europy Środkowo-Wschodniej
PublikacjaCelem artykułu jest ocena pozycji konkurencyjnej w handlu usługami wybranych krajów Europy Środkowo-Wschodniej – Czech, Estonii, Litwy, Łotwy, Polski, Słowacji oraz Węgier na tle gospodarki światowej. Dane wykorzystane do analizy pochodzą z bazy danych WIOD i obejmują lata 1995 – 2011. Podstawą oceny pozycji konkurencyjnej jest wskaźnik RCA obliczony na podstawie krajowej wartości dodanej oraz na podstawie eksportu brutto. Źródłem...
-
Badania eksperymentalne słupów CFST z betonem zwykłym i ekspansywnym
PublikacjaPraca przedstawia badania eksperymentalne ponad 40 słupów CFST. Analizie poddano wyniki siły niszczącej słupy w aspekcie grubości stalowego płaszcza, smukłości słupa, rodzaju betonu wypełniającego stalową rurę (zwykły i ekspansywny) i jego wytrzymałości a także sposobu obciążania słupa (przez rdzeń lub przez cały przekrój). Sprawdzono efektywność słupów CFST z użyciem betonu ekspansywnego i zwykłego rozumianą jako stosunek nośności...
-
Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons
PublikacjaChemical vapor transport (CVT) method is widely used for bulk black phosphorus (BP) fabrication. In this work, we demonstrate that CVT provides a route for the fabrication of BP nanoribbons and nanobelts. This method consists of a two-step procedure, including initial BP column growth using the CVT technique, followed by ultrasonic treatment and centrifugation. The obtained nanostructures preserve BP column dimensions, forming...
-
Ellipsometric study of carbon nitride films deposited by DC-magnetron sputtering
PublikacjaWe report the optical properties of a carbon nitride (CNx) film as a function of nitrogen concentration (N/C) of the deposited film. As nitrogen concentration is increased (N/C ratio) in a CNx film, the refractive index and band gap also increase. The real and imaginary parts, n and k (refractive index and extinction coefficient) of the complex refraction index of carbon nitride films were determined by spectroscopic ellipsometry...
-
Analysis of Measurement Errors in Rail Vehicles’ Pantograph Inspection System
PublikacjaThe paper presents an approach to evaluation of height measurement errors in laser scanning inspection system. The system, consisting of a laser line generator and a specialized camera, is dedicated to diagnosing carbon contact strips of railway vehicles’ pantographs. While height measurement resolution is easily computable based on system parameters, determining the measurement error is troublesome due to numerous impacts. As...
-
Multistage treatment wetland for treatment of reject waters from digested sludge dewatering
PublikacjaThe paper presents the influence of sewage composition on treatment in pilot-scale facility for reject waters (RW) from sewage sludge centrifugation. The facility consisted of mechanical (two tanks with 10 d retention each) and biological parts composed of three subsurface flow reed beds working in batch. Two years of monitoring of the facility proved high efficiency removal of predominant pollutants: COD 75–80%, BOD 82.2–95.5%...
-
MECHANICAL PROPERTIES OF BOTTOM ASH – DREDGED MATERIAL MIXTURES IN LABORATORY TESTS
PublikacjaBottom ash from EC Gdańsk and dredged material taken from the mouth of The Vistula were mixed to form an engineering material used for dike construction. Mixtures with different bottom ash content were tested in laboratory to determine its basic physical and mechanical properties. The optimum bottom ash–dredged material mixture, built in the corps of the test dike, contains 70% of ash. The optimum bottom ash content in the mixture...
-
Electrochemical Characterization of Gelatine Derived Ceramics
PublikacjaNew materials obtained by pyrolysis of gelatine (G) and poly(1,2-dimethylsilazane) (PSN) (weight ratio: G/PSN 70/30) at temperatures 700 and 900 °C were characterized by SEM and Raman spectroscopy. The presence of ceramics influences on the cluster size of the materials. Electrochemical tests were performed by cyclic voltammetry and galvanostatic cyclic polarization. The capacity of G/PSN was 464 and 527 mAh/g for materials pyrolysed...
-
The performance of H2O, R134a, SES36, ethanol, and HFE7100 two-phase closed thermosyphons for varying operating parameters and geometry
PublikacjaIn this study, the influences of different parameters at performance two-phase closed thermosiphon (TPCT) was presented. It has been confirmed that the working fluid, as well as operating parameters and fill ratio, are very important factors in the performance of TPCT. The article shows characteristics of gravitational tube geometr ies, as well as the technical characteristic of the most important system components, i.e., the evaporator/condenser....
-
Ageing of Society — Local Disparities. Classification of the Pomorskie Voivodship Communes According to the Pace and Progress of Local Communities’ Ageing
PublikacjaThe article deals with the issues of local disparities in the field of advancement and pace of demographic ageing. The subjects of the research were communes of the Pomorskie Voivodship. The purpose of the article — i.e., diagnosing and assessing the progress and pace of ageing of local communities in all 123 communes of the Pomorskie Voivodship, was achieved using a combination of traditional measures of ageing: age factor,...
-
Structural optimization of microjet array cooling system
PublikacjaThe single phase heat transfer from an upward facing, horizontal copper surface to arrays of impinging water jets was experimentally investigated. Experimental configuration allows for a free-surface unconfined jets flow. Square nozzles 50 × 100 μm arranged in four different geometries were used. Additionally, for the set of two jets array geometry was varied by adjusting the nozzle to nozzle distance. The area averaged heat transfer...
-
Structural and mechanical properties of hydroxyapatite coatings formed by ion-beam assisted deposition
PublikacjaThe ion-beam assisted deposition (IBAD) is an advanced method capable of producing crystalline coatings at low temperatures. We determined the characteristics of hydroxyapatite Ca10(PO4)6(OH)2 target and coatings formed by IBAD using X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray (EDX). The composition of the coatings'...
-
Hybrid Processing by Turning and Burnishing of Machine Components
PublikacjaThe paper presents a method of hybrid manufacturing process of long 5 shafts and deep holes by simultaneous turning and burnishing method. The tech- 6 nological results of the research focus on the influence of the basic technological 7 parameters of this process on the surface roughness of piston rods of hydraulic 8 cylinders. Research results are presented in the graphs as well as mathematical 9 formula. Set of samples were made...
-
Synchronized six-step voltage generation in high-speed PMSM drive
PublikacjaSynchronized voltage generation has already been considered in the context of pulse width modulation (PWM). References prove that synchronized PWM substantially decreases subharmonics in inverter output voltage when operating with low switching-to-fundamental frequency ratio. This paper identifies problems of unsynchronized voltage generation in electric drives under six-step inverter operation. Guidelines for the synchronization...
-
Comparison of Acoustic and Visual Voice Activity Detection for Noisy Speech Recognition
PublikacjaThe problem of accurate differentiating between the speaker utterance and the noise parts in a speech signal is considered. The influence of utilizing a voice activity detection in speech signals on the accuracy of the automatic speech recognition (ASR) system is presented. The examined methods of voice activity detection are based on acoustic and visual modalities. The problem of detecting the voice activity in clean and noisy...
-
A simplified channel estimation procedure for NB-IoT downlink
PublikacjaThis paper presents a low-complexity channel estimation procedure which is suitable for use in energy-efficient NB-IoT user equipment devices. The procedure is based on the well-established least squares scheme, followed by linear interpolation in the time domain and averaging in the frequency domain. The quality of channel estimation vs. signal-to-noise ratio is evaluated for two channel models and compared with the performance...
-
Detailed studies of superconducting properties of Y2Pd1.25Ge2.75
PublikacjaWe report a successful synthesis of a high-purity intermetallic germanide Y2Pd1.25Ge2.75, crystallizing in the disordered variant of the AlB2-type structure. A single-phase sample was obtained via arc-melting by deliberately tuning the composition out of the ideal 2:1:3 ratio. Specific heat, electrical resistivity and magnetization measurements show that the compound is a weakly-coupled (λ e-p = 0.58) type-II superconductor with...
-
Analysis of the structure of the atomized fuel spray with marine diesel engine injector in the early stage of injection
PublikacjaThis paper presents the results of the experimental research of the atomized fuel spray with the marine diesel engine injector in the constant volume chamber. The specificity of the phenomena occurring in the marine engine cylinder was the reason to use the optical visualisation method in the studies – the Mie scattering technique. This work presents an analysis of the influence of different geometry of outlet orifice and opening...
-
Effect of soil on the capacity of viscous dampers between adjacent buildings
PublikacjaThis study investigated the seismic pounding of two adjacent buildings considering soil–structure interaction (SSI). A comprehensive parametric study of buildings with different heights was performed to reveal the pounding-involved behaviour considering the soil effect. Wavelet transform has been conducted to gain insight into the differences in the frequency contents of the impact forces between fixed- and flexible-base adjacent...
-
On Wrinkling in Sandwich Panels with an Orthotropic Core
PublikacjaThis paper deals with the local loss of stability (wrinkling) problem of a thin facing of a sandwich panel. Classical solutions to the problem of facing instability resting on a homogeneous and isotropic substructure (a core) are compared. The relations between strain energy components associated with different forms of core deformations are discussed. Next, a new solution for the orthotropic core is presented in detail, which...
-
Unity-Gain Zero-Offset CMOS Buffer with Improved Feedforward Path
PublikacjaA voltage unity-gain zero-offset CMOS amplifier with reduced gain error and increased PSRR (power supply rejection ratio) is proposed. The amplifier uses two feed mechanisms, negative feedback and supporting positive feedforward, to achieve low deviation from unit gain over the entire input range. The circuit, designed in a standard 180-nanometer 1.8-voltage CMOS process, is compared with two known buffers of similar topology,...
-
Chemical Vapor Transport Route toward Black Phosphorus Nanobelts and Nanoribbons
PublikacjaChemical vapor transport (CVT) method is widely used for bulk black phosphorus (BP) fabrication. In this work, we demonstrate that CVT provides a route for the fabrication of BP nanoribbons and nanobelts. This method consists of a two-step procedure, including initial BP column growth using the CVT technique, followed by ultrasonic treatment and centrifugation. The obtained nanostructures preserve BP column dimensions, forming...
-
Influence of bush wear in water lubricated marine stern tube bearings with shaft misalignment
PublikacjaWater lubricated propeller shaft bearings are frequently employed on modern ships due to their advantages such as durability, simplicity and low price. Specific working conditions on ships cause shaft misalignment which often results in rapid wearing of bush and shaft. Shaft misalignment could be an effect of manufacturing or assembly faults but sometimes it appears due to hull or shaft deformation. The wearing process has influence...
-
From structure to luminescence investigation of oxyfluoride transparent glasses and glass-ceramics doped with Eu3+/Dy3+ ions
PublikacjaGlasses and glass-ceramics with nominal composition 73 TeO2– 4BaO– 3Bi2O3–18SrF2-2RE2O3 (where RE = Eu, Dy) have been synthesized by conventional melt-quenching technique and subsequent heat treatment at 370 °C for 24 h in air atmosphere. Various Eu3+ to Dy3+ molar ratio have been applied to investigate luminescence properties in both glass and glass-ceramic matrices. Especially, white light emission through simultaneous excitation...
-
EM-Driven Size Reduction and Multi-Criterial Optimization of Broadband Circularly-Polarized Antennas Using Pareto Front Traversing and Design Extrapolation
PublikacjaMaintaining small size has become an important consideration in the design of contemporary antenna structures. In the case of broadband circularly polarized (CP) antennas, miniaturization is a challenging process due to the necessity of simultaneous handling of electrical and field properties (reflection, axial ratio, gain), as well as ensuring sufficient frequency range of operation, especially at the lower edge of the antenna...
-
Comprehensive evaluation of physical properties and carbon dioxide capacities of new 2-(butylamino)ethanol-based deep eutectic solvents
PublikacjaThe aim of this research was to assess the impact of the components of alkanolamine deep eutectic solvents (DESs) on the physical properties of those DESs and their carbon dioxide capacity. To achieve this goal, novel deep eutectic solvents were synthesized by using 2-(butylamino)ethanol (BAE) as the hydrogen bond donor (HBD), along with tetrabutylammonium bromide TBAB), tetrabutylammonium chloride (TBAC), or tetraethy- lammonium...
-
Influence of Soft Soil Samples Quality on the Compressibility and Undrained Shear Strength – Seven Lessons Learned From the Vistula Marshlands
PublikacjaThis technical article presents the influence of sample quality on the compressibility parameters and undrained shear strength ( c u ) of soft soils from the Vistula Marshlands. The analysis covers: (1) quality of soft soil according to three criteria: void ratio (Δ e / e 0 index), volumetric strain (Δ ɛ v ) and C r / C c ratio; (2) influence of storage time on quality; (3) influence of sample quality on undrained shear strength...
-
Comparison of Absorbed and Intercepted Fractions of PAR for Individual Trees Based on Radiative Transfer Model Simulations
PublikacjaThe fraction of absorbed photosynthetically active radiation (fAPAR) is a key parameter for estimating the gross primary production (GPP) of trees. For continuous, dense forest canopies, fAPAR, is often equated with the intercepted fraction, fIPAR. This assumption is not valid for individual trees in urban environments or parkland settings where the canopy is sparse and there are well-defined tree crown boundaries. Here, the distinction...
-
Differentiated intraepithelial neoplasia - Female, 55 - Cell image [4080730008351231]
Dane BadawczeThis is the histopathological image of CERVIX UTERI cell sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
-
Determination of flow properties of a serial connection of a directional control valve with (C=5.7, b=0.32) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient...
-
Determination of flow properties of a serial connection of a directional control valve with (C=2.1, b=0.14) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient...
-
Determination of flow properties of a serial connection of a pressure relief valve with (C=7.3, b=0.49) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
-
Determination of flow properties of a serial connection of a directional control valve with (C=2.8, b=0.25) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient...
-
Determination of flow properties of a serial connection of a directional control valve with (C=5.5, b=0.37) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient...
-
Determination of flow properties of a serial connection of a pressure relief valve with (C=6.4, b=0.45) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
-
Determination of flow properties of a serial connection of a pressure relief valve with (C=6.2, b=0.38) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
-
Determination of flow properties of a serial connection of a directional control valve with (C=2.4, b=0.26) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient...
-
Determination of flow properties of a serial connection of a pressure relief valve with (C=3.3, b=0.40) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a pressure relief valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> PRV -> ambient...
-
Determination of flow properties of a serial connection of a directional control valve with (C=2.0, b=0.11) and a air blow gun from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a air blow gun (with nozzle removed) arranged in-line. Three test configurations were used: (1) being emptied tank -> DCV -> ambient...
-
Determination of flow properties of a parallel connection of two pneumatic elements with (C=2.10, b=0.14) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
-
Determination of flow properties of a parallel connection of two pneumatic elements with (C=2.80, b=0.25) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...
-
Determination of flow properties of a parallel connection of two pneumatic elements with (C=2.10, b=0.14) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Dane BadawczeThe aim of the study was to determine the flow properties of parallel connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for a directional control valve and a pressure relief valve arranged in parallel. Three test configurations were used: (1) being emptied tank -> DCV -> ambient atmosphere,...