Filtry
wszystkich: 1575
-
Katalog
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: PB ISOTOPIC RATIO
-
Investigations on strength and fracture in RC beams scaled along height or length
PublikacjaThe objective of the present paper is to identify experimentally and theoretically differing failure mechanisms in reinforced concrete beams subjected to four-point bending for a separate variation of the depth and length at the constant thickness. Experiments were performed on reinforced concrete beams under four-point bending. Different failure mechanisms included steel yielding, diagonal tension or shear- compression depending...
-
Chemical properties of bismuth telluride – carbon composites.
Dane BadawczeCarbon nanotubes and amorphous carbon have been introduced into bismuth telluride matrix (in 0.15 and 0.30 wt % ratio) in order to investigate influence of carbon on composite’s thermoelectric properties. Composites with well-dispersed additives have been obtained by sonication and ball-milling. Chemical composition of materials was confirmed by XPS...
-
ZRÓŻNICOWANIE STRUKTURY KAPITAŁOWO-MAJĄTKOWEJ W ZALEŻNOŚCI OD WIELKOŚCI PRZEDSIĘBIORSTWA
PublikacjaW artykule przedstawiono różnice w kształtowaniu struktury kapitałowo-majątkowej pomiędzy małymi, średnimi i dużymi przedsiębiorstwami. W trakcie przeprowadzonych badań uwzględniono 97 471 sprawozdań finansowych przedsiębiorstw, prowadzących działalność gospodarczą w 12 różnych działach polskiej gospodarki narodowej. Do potwierdzenia zróżnicowania struktury kapitałowo-majątkowej w zależności od wielkości przedsiębiorstwa wykorzystano...
-
The quality of sewage sludge stabilized for a long time in reed basins
PublikacjaThe aim of the work was to determine changes of long-term sewage sludge quality stabilized in reed basins from 7-15 years. The following parameters were evaluated: dry matter and organic matter concentration, nitrogen, phosphorus, and selected heavy metal (Cd, Ni, Pb, Cr, Cu, Zn) fractions. The material for the investigations was collected from 4 reed basin systems (utilisated sewage sludge) located in conventional WWTPs in Denmark...
-
Zastosowanie technik chemometrycznych w analityce i monitoringu środowiskowym
PublikacjaW pracy przedstawiono wyniki monitoringu przybrzeżnej strefy Morza Bałtyckiego w rejonie Zatoki Gdańskiej. W projekcie oznaczano związki z grupy WWA, HC, OPNPS, OCP5, VOCl oraz wybrane metale ciężkie (Pb, Zn, Cd, Cu). Podjęto próbę wyjaśnienia występowania określonych grup zanieczyszczeń w próbkach wody morskiej poprzez charakteryzację źródeł zanieczyszczeń wód lądowych, a także dzięki wyjaśnieniu statystycznie istotnych korelacji...
-
Fast-SEC coupled to ICP-MS for selected metal determination and its stability over time in polish wine
PublikacjaMetal ions contribute to the wine browning (as reaction catalysts), turbidity (in complexes), and astringency (due to inter- action with tannins). Being aware that bioavailability and metabolism of metal ions in the human body are strictly related with their concentration and the form they occur it is important to monitor not only the total content of metals but also their speciation. Thus, we can obtain more information about...
-
Determination of heavy metals in eyeshadows from China
PublikacjaPersonal care products and cosmetics are used daily by many people, causing local exposure to certain chemical substances through the application directly inside the oral cavity, on the skin, lips, eyes, and mucosa. Eyeshadows are among the most commonly used types of cosmetics. According to scientifc reports, they may contain heavy metals, especially in non-original products. The exposure to said heavy metals may cause local skin...
-
Seashore sediment and water chemistry at the Admiralty Bay (King George Island, Maritime Antarctica) – geochemical analysis and correlations between the concentrations of chemical species
PublikacjaThis study covers water and sediment chemical characteristics by the western shore of Admiralty Bay (King George Island, Antarctica) in 2016. Chemical processes between sediment and water have been described based on the determination of ions, metals, non-metals, and TOC concentrations. Rock weathering is an important source of Fe, Ni, Co, Al in the seashore area. The PCA shows the impact of acidification in the release metals...
-
Accumulation of radioisotopes and heavy metals in selected species of mushrooms
PublikacjaSeven species of forest mushrooms from different regions of Poland (edible: Imleria badia, Cantharellus cibarius, Xerocomus subtomentosus, Suillus luteus and inedible by humans but being food for animals: Paxillus involutus, Tylopilus felleus and Russula emetica) were analyzed for radioisotope activity (Cs-137, K-40, Bi-214 and Pb-210) as well as concentrations of heavy metals (aluminum, chromium, cadmium, manganese, iron, lead,...
-
Surface sediments pollution due to shipwreck s/s “Stuttgart”: a multidisciplinary approach
PublikacjaShipwrecks may pose a serious source of pollution for marine ecosystems. For this reason, it is of great importance to perform a marine ecosystem risk assessment due to plausible wreck presence. One of elements of such an assessment is determining the state of the environment in the vicinity of the wreck. In the work presented, the results of studies on surface sediments samples collected around the s/s Stuttgart ship sunk during...
-
Data points of structures of R1233zd(E) flowing in a circular minichannel at low, medium and high values of saturation pressure
Dane BadawczeDatabase present structures of two-phase flow of R1233zd(E) in 3 mm vertical channel. Database contains datapoints which contain information of reduced pressure (ratio of saturation pressure and critical pressure), quality and mass velocity. 4 two phase structures are distinguished: bubbly flow, slug flow, intermittent flow and annular flow.
-
Personal income tax - tax scales in 1992–2019
Dane BadawczeThe tax rate is the ratio (usually expressed as a percentage) at which a business or person is taxed. There are several methods used to present a tax rate: statory, average, marginal, and effective. These rates can also be presented using different definitions applied to a tax base: inclusive and exclusive.
-
Collagen type II–hyaluronan interactions – the effect of proline hydroxylation: a molecular dynamics study
PublikacjaHyaluronan–collagen composites have been employed in numerous biomedical applications. Understanding the interactions between hyaluronan and collagen is particularly important in the context of joint cartilage function and the treatment of joint diseases. Many factors affect the affinity of collagen for hyaluronan. One of the important factors is the ratio of 3- or 4-hydroxy proline to proline residues. This article presents...
-
Effect of small quantities of potassium promoter and steam on the catalytic properties of nickel catalysts in dry/combined methane reforming
PublikacjaCarbon dioxide and methane are two of the principal greenhouse gases. Reduction of their content in the atmosphere is currently the subject of much worldwide research. Dry and combined reforming of methane are effective methods of CO2 and CH4 utilization and production of synthesis gas (syngas) in chemical technology. Testing of catalysts that provide the desired H2/CO ratio and long operation time is one of the critical aspects...
-
Modelling and optimisation of MXene-derived TiO2/Ti3C2 synthesis parameters using Response Surface Methodology based on the Box–Behnken factorial design. Enhanced carbamazepine degradation by the Cu-modified TiO2/Ti3C2 photocatalyst
PublikacjaIn the present study, a hydrothermal method in a water/ethanol environment was used for the first time to obtain novel Cu/TiO2/Ti3C2 composites with high photocatalytic activity for the degradation of carbamazepine (CBZ) under simulated solar light. The Box–Behnken factorial design was coupled with Response Surface Methodology (RSM) for synthesis parameter optimisation. The effect of different synthesis parameters, including temperature, time...
-
Resonant and nonresonant excitation of waves in a planar magnetosonic flow
PublikacjaForced propagation of perturbations in a magnetosonic wave are considered. The driving force may be caused by stimulated Mandelstam–Brillouin scattering of optic waves or by intense magnetosonic exciter. Some heating-cooling function which takes into account radiative cooling and unspecified heating is taken into consideration, as well as nonlinearity of a medium. Both these factors make the excitation particular. The analytical...
-
Theoretical and Economic Evaluation of Low-Cost Deep Eutectic Solvents for Effective Biogas Upgrading to Bio-Methane
PublikacjaThis paper presents the theoretical screening of 23 low-cost deep eutectic solvents (DESs) as absorbents for effective removal of the main impurities from biogas streams using a conductor-like screening model for real solvents (COSMO-RS). Based on thermodynamic parameters, i.e., the activity coefficient, excess enthalpy, and Henry’s constant, two DESs composed of choline chloride: urea in a 1:2 molar ratio (ChCl:U 1:2), and choline...
-
Inverse and forward surrogate models for expedited design optimization of unequal-power-split patch couplers
PublikacjaIn the paper, a procedure for precise and expedited design optimization of unequal power split patchcouplers is proposed. Our methodology aims at identifying the coupler dimensions that correspond to thecircuit operating at the requested frequency and featuring a required power split. At the same time, thedesign process is supposed to be computationally efficient. The proposed methodology involves two typesof auxiliary models (surrogates):...
-
Jeffreys heat conduction in coupled semispaces subjected to interfacial heating
PublikacjaA Jeffreys heat conduction problem for coupled semispaces subjected to the action of an interfacial heat source was defined. An analytical solution of the problem was derived for a polynomial specific power of the heat source using the Laplace transform approach. The asymptotic and parametric analysis was performed for different ratios of thermal conductivities , thermal diffusivities , thermal relaxation times and coefficients...
-
Gas Composition Influence on the Properties of Boron-Doped Diamond Films Deposited on the Fused Silica
PublikacjaThe main subject of this study are molecular structures and optical properties of boron-doped diamond films with [B]/[C] ppm ratio between 1000 and 10 000, fabricated in two molar ratios of CH 4 -H 2 mixture (1 % and 4 %). Boron-doped diamond (BDD) film on the fused silica was presented as a conductive coating for optical and electronic purposes. The scanning electron microscopy images showed homogenous and polycrystalline surface...
-
Collaborative Exploration of Trees by Energy-Constrained Mobile Robots
PublikacjaWe study the problem of exploration of a tree by mobile agents (robots) that have limited energy. The energy constraint bounds the number of edges that can be traversed by a single agent. We use a team of agents to collectively explore the tree and the objective is to minimize the size of this team. The agents start at a single node, the designated root of the tree and the height of the tree is assumed to be less than the energy...
-
Microwave assisted liquefaction with crude glycerol as a potential method of brewer's spent grain utylization
PublikacjaBrewer's spent grain was applied as a low-cost industrial type of lignocellulose biomass in a liquefaction and solvent: biomass ratio on the efficiency of the process, chemical structure and basic properties of obtained prepared polyols and soil residues shed light on the biomass degradation mechanism through application of microwaves and further reaction of degradation products with solvent particles.
-
The AFM micrographs of isotropic etching silicon substrates (111)
Dane BadawczeThe DataSet contains the atomic force microscope images of isotropic etching silicon substrates (111). The silicon wafers were etched in a mixture of nitric acid, hydrofluoric acid, and acetic acid in the ratio of 40:1:15. The soaking time for the substrates was from 20 to 90 seconds
-
Euilibrium composition of CH4-CO2-CO-H2-H2O-C system for CO2/H2/H2O methanation
Dane BadawczeThe equilibrium compositions of CH4, CO2, CO, H2, H2O and C under the methanation reaction of 1:2 CO:H2 syngas mixtures were supplied with this dataset
-
Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a Impulse Radio Interference
PublikacjaThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. IEEE 802.15.4a UWB signal is being used as interferer, also with frame structure modifications which lead to change spectrum of the interference. Equations and coefficients which allow to calculate ratio between power of useful and interference signal are also presented.
-
Concept of Compatibility Region for the Evaluation of IR UWB Electromagnetic Compatibility
PublikacjaThis paper presents a new proposal for the unified evaluation of ultra wideband and narrowband radio communication systems electromagnetic compatibility, called “compatibility region”. The idea of compatibility region is based on the relation between the ratio of narrowband to ultra wideband signal power in a receiver and some transmission quality indicators (bit error rate, effective data rate).
-
Assessment of metal removal in a surface flow constructed wetland treating landfill leachate
PublikacjaThe study concerns heavy metal retention and transformation processes in a free water surface constructed wetland treating landfill leachate in a temperate climate. The total effectiveness of heavy metals removal in the analyzed CW was evaluated basing on heavy metals inflow and outflow concentrations. The concentrations of eight heavy metals (Fe, Mn, Zn, Pb, Ni, Cu, Cr, Cd) in landfill leachate (LL) and sediments were measured....
-
Distribution and removal efficiency of heavy metals in two constructed wetlands treating landfill leachate
PublikacjaThe results of heavy metals (Fe, Mn, Zn, Ni, Cu, Cr, Pb, Cd) removal and partitioning between aqueous and solid phases at two wetlands (TWs) treating municipal landfill leachates are presented. One of the TWs is a surface flow facility consisting of 10 ponds. The other TW is a newly constructed pilot-scale facility consisting of three beds with alternately vertical and horizontal sub-surface flow. The metals concentrations were...
-
Reduction of vibrations of steel structure models with Polymeric Bearings - experimental study
PublikacjaEarthquake-induced ground motions are the most severe and unpredictable threats to the structures all around the world. Therefore, designing earthquake protective systems has become an extremely challenging problem in civil engineering. Base isolation is one of the most popular and widely adopted methods of protecting structures against earthquake forces. The present paper reports the results obtained from the shaking table experimental...
-
RAPORT - EKSPERTYZA Z POMIARÓW DRGAŃ LINII WAŁÓW NA JEDNOSTCE ORP „DĄBIE”
PublikacjaEkspertyza diagnostyczna dotycząca stanu technicznego dwóch linii transmisji mocy (linii wałów) opracowana na podstawie przeprowadzonych pomiarów drgań w 26 punktach pomiarowych, przy jednoczesnej pracy silników napędowych L i PB (wspólnej pracy linii wałów obu burt), w II zakresach ustalonego obciążenia „pół-naprzód” i „cała-naprzód”. Pomiary prędkości i przyspieszeń drgań generowanych przez węzły konstrukcyjne okrętowego układu...
-
Blended natural and synthetic coagulants for the COD and BOD removal from surface water; optimization by response surface methodology: The case of Gibe river
PublikacjaA novel wastewater treatment method is presented in this study. It combines natural coagulants derived from watermelon seeds with the commonly used synthetic coagulant alum. This research demonstrates a remarkable synergy between these two coagulants in removing nutrients from Gibe River wastewater. Combining natural and chemical coagulants often improves water treatment by enhancing particle destabilization, accelerating floc...
-
Modeling N2O behavior during denitrification with different carbon sources and electron acceptors
PublikacjaA mathematical model was developed for identification of the most important mechanism leading to nitrous oxide (N2O) accumulation in denitrifying activated sludge systems. The activated sludge model No. 2d (ASM2d) was extended to include intermediate three steps of the denitrification process. The formation and accumulation of nitric oxide (NO) was assumed to be very low in the performed laboratory experiments. These experiments...
-
Auxetic foams
PublikacjaThis paper presents a method of producing auxetic polyurethane foams (PUFs) and their unique properties. The experience was based on a synthesis of traditional flexible polyurethane foam and thermal conversion to auxetic foam. The foam specimens were transformed from conventional Poisson's ratio to auxetic (negative Poisson's ratio) [1]. Basic research was performed to determine the mechanical properties and cell structure. Auxetic...
-
Detection and Mitigation of GPS Spoofing Based on Antenna Array Processing
PublikacjaIn this article authors present an application of spatial processing methods for GPS spoofing detection and mitigation. In the first part of this article, a spoofing detection method, based on phase delay measurements, is proposed. Accuracy and precision of phase delay estimation is assessed for various qualities of received signal. Spoofing detection thresholds are determined. Efficiency of this method is evaluated in terms of...
-
Euilibrium composition of CH4-CO2-CO-H2-H2O system for CO2/H2/H2O methanation
Dane BadawczeThe equilibrium compositions of CH4, CO2, CO, H2, H2O without C under the methanation reaction of 1:2 CO:H2 syngas mixtures were supplied with this dataset
-
Enhanced-Performance Circularly Polarized MIMO Antenna with Polarization/Pattern Diversity
PublikacjaDesign of a compact wideband circularly polarized (CP) multiple-input multiple-output (MIMO) antenna with polarization diversity is proposed and characterized for off-body communication. The antenna is based on a simple coplanar waveguide (CPW)-fed monopole extension of the microstrip line. The orthogonal field components required by CP are induced using a simply modified right/left side ground plane. In particular, a stub extending...
-
Influence of the boron doping level on the electrochemical oxidation of the azo dyes at Si/BDD thin film electrodes
PublikacjaIn this study the efficiency of electrochemical oxidation of aromatic pollutants, such as reactive dyes, at boron-doped diamond on silicon (Si/BDD) electrodes was investigated. The level of [B]/[C] ratio which is effective for the degradation and mineralization of selected aromatic pollutants, and the impact of [B]/[C] ratio on the crystalline structure, layer conductivity and relative sp3/sp2 coefficient of a BDD electrode were...
-
Influence of the boron doping level on the electrochemical oxidation of raw landfill leachates: advanced pre-treatment prior to the biological nitrogen removal
PublikacjaThe electrochemical oxidative treatment of landfill leachates (LLs) containing high amounts of ammonia nitrogen and organic matter was used as a promising method, prior to biological processes, to achieve the final effluent quality that would be acceptable by current regulations. The deposited boron-doped diamond electrodes (BDDs) with different boron doping concentrations (10000, 5000 and 500 ppm of B) were applied as anodes....
-
WYDATKI INWESTYCYJNE WOJEWÓDZTW SAMORZĄDOWYCH PO WPROWADZENIU INDYWIDUALNEGO WSKAŹNIKA ZADŁUŻENIA
PublikacjaOkreślenie dopuszczalnego poziomu zadłużenia jest ważną kwestią dla każdej jednostki samorządu terytorialnego w Polsce, a jej ranga jeszcze rośnie, jeśli samorząd odczuwa silną presję na dbanie o rozwój obszaru, na którym funkcjonuje, borykając się równocześnie z niedostatkiem dochodów. Taka sytuacja dotyczy większości województw samorządowych, które spośród wszystkich szczebli struktury samorządowej...
-
Effect of Soft Handover on the Capacity of WCMDA/FDD Interfece Using MRC RAKE Receiver in Uplink
PublikacjaIn the paper the mechanism of soft and hard hanover in UMTS is presented. Simulation tests for different services having various performance requirements and transmission rates have beeen made. Simulation results showing effect of soft handover in comparison with hard handover on the capacity of WCMDA/FDD radio interfaceare described, when the RAKE receiver with Maximal Ratio Combining has been implemented in RNC.
-
Fracture Areas Quantitative Investigating of Bending-Torsion Fatigued Low-Alloy High-Strength Steel
PublikacjaIn this study, the impact of pseudo-random non-proportional bending-torsion fatigue loadings proportion on the fatigue life and the fracture surface topography was analyzed. Investigation was carried out for 24 specimens made of S355J2 steel with 11 different ratios of maximum stresses λ. For these cases, after the fatigue tests, the surface topography measurements were carried out using an optical profilometer, using the focus...
-
Copolymerization of Styrene and Pentadecylphenylmethacrylate (PDPMA): Synthesis, Characterization, Thermomechanical and Adhesion Properties
PublikacjaThe copolymerization of styrene (St) with a bioderived monomer, pentadecylphenylmethacrylate (PDPMA), via atom transfer radical polymerization (ATRP) was studied in this work.The copolymerization reactivity ratio was calculated using the composition data obtained from1HNMR spectroscopy, applying Kelen-Tudos and Finemann-Ross methods. The reactivity ratio of styrene (r1=0.93) and PDPMA (r2=0.05) suggested random copolymerization...
-
Zeolitic imidazolate framework (ZIF-8) modified cellulose acetate NF membranes for potential water treatment application
PublikacjaIn this study, cellulose acetate (CA)-based nanofiltration membranes, modified with zeolitic imidazole framework-8 (ZIF-8) particles, were prepared with various ZIF-8 contents (0, 0.1, 0.25, 0.5, 1 and 2 wt%), to obtain membranes with improved flux and filtration performance by combining advantages of CA polymer and ZIF-8 metal-organic frameworks. Removal efficiency studies were carried out with bovine serum albumin and two different...
-
EXPERIMENTAL AND NUMERICAL INVESTIGATION ON SPECIMEN GEOMETRY EFFECT ON THE CTOD VALUE FOR VL-E36 SHIPBUILDING STEEL
PublikacjaThere are special cases in the marine industry, where additional material tests, such as the fracture toughness test, must be performed. Additional fracture toughness tests, such as CTOD (Crack Tip Opening Displacement), are typically performed on three-point bend specimens. The dimension that defines all the specimen dimensions is the thickness of the material to be tested. It is recommended by classification societies (e.g. DNVGL)...
-
Methods for physical impairment constrained routing with selected protection in all-optical networks
PublikacjaIn this paper, we investigate the problem of survivable all-optical routing in WDM networks with physical impairments. One of the recent key issues in survivable optical network design refers to maximization of the ratio of routeable demands while keeping the overall network cost low. In WDM networks, this goal can be achieved by routing as many demands in all-optical way as possible. Based on the latest technical trends driven...
-
Canonical switched capacitor converters. Comments, complements, and refinements
PublikacjaSwitched Capacitor Converters (SCC) form useful blocks in low/medium power applications as they are suitable for integration, both as off-chip and on-chip IC realizations. However, the problem with SCC is that their voltage conversion ratio is topology-dependent. By changing the SC circuit configuration, we can gain control over voltage conversion but the available ratio remains of a discrete nature, i.e. it maps into a countable...
-
EFFECT OF ANTIOXIDANTS ON THE STABILITY OF PITCH- BASED POLYMER TO THERMO-OXIDATIVE ACTION
PublikacjaThe influence of stabilizers – hydrogen donors – on the processes of thermooxidative destruction of pitch-based polymer has been investigated. It is shown that Irganox has not stabilizing effect on pitch-based polymer and melamine slightly retards the destructive process. A mixture of melamine and Irganox exhibits synergetic stabilizing effect and at the optimum ratio it can be used to prevent unwanted thermooxidative processes...
-
Thermal self-action effects for acoustic beams containing fronts in a Maxwell relaxing fluid
PublikacjaThis paper examines the thermal self-action of acoustic beams in a Maxwell relaxing fluid. This type of thermal self-action differs from that in a Newtonian fluid and behaves differently depending on a ratio of sound period and time of thermodynamic relaxation. The self-action which relates to sound beams containing shock fronts is also discussed. In addition, stationary and non-stationary types of self-action are considered.
-
Kształtowanie wartości wskaźników wspomagania finan-sowego przez ponadprzeciętnie rentowne MSP w okresie dobrej i złej koniunktury gospodarczej
PublikacjaW artykule porównano kształtowanie wartości wskaźników z obszaru wspomagania finansowego przez ponadprzeciętnie rentowne MSP w okresie dobrej i złej koniunktury gospodarczej. Celem przeprowadzonych badań było ponadto zaproponowanie przedziałów wartości rekomendowanych dla wskaźników z obszaru wspomagania finansowego, z osobna dla okresu dobrej jak i złej koniunktury gospodarczej. W trakcie przepro-wadzonych badań uwzględniono...
-
Kształtowanie wartości wskaźników płynności finansowej przez ponadprzeciętnie rentowne MSP w okresie dobrej i złej koniunktury gospodarczej
Publikacja: W artykule porównano kształtowanie wartości wskaźników z obszaru płynności finansowej przez ponadprzeciętnie rentowne MSP w okresie dobrej i złej koniunktury gospodarczej. Celem przeprowadzonych badań było ponadto zaproponowanie przedziałów wartości rekomendowanych dla wskaźników z obszaru płynności finansowej z osobna dla okresu dobrej, jak i złej koniunktury gospodarczej. W trakcie przeprowadzonych badań uwzględniono 67 317...