Filters
total: 5154
filtered: 4542
-
Catalog
- Publications 4542 available results
- Journals 109 available results
- Conferences 1 available results
- People 54 available results
- Projects 11 available results
- Research Equipment 1 available results
- e-Learning Courses 55 available results
- Events 5 available results
- Open Research Data 376 available results
Chosen catalog filters
displaying 1000 best results Help
Search results for: Urea–water solution
-
Molecular hydrogen solvated in water – A computational study
PublicationThe aqueous hydrogen molecule is studied with molecular dynamics simulations at ambient temperature and pressure conditions, using a newly developed flexible and polarizable H2 molecule model. The design and implementation of this model, compatible with an existing flexible and polarizable force field for water, is presented in detail. The structure of the hydration layer suggests that first-shell water molecules accommodate the...
-
A solution of the integrated µBIST for functional and diagnostic testing in mixed-signal electronic embedded systems
PublicationMain problem of the paper is testing of analog circuits and blocks in mixed-signal electronic embedded systems (EESs), using the built-in self-test (BIST) technique. The integrated mBIST based on reusing signal blocks already present in an EES, such as processors, memories, ADCs, is presented. The novelty of the solution is the extended functionality of the mBIST. It can perform 2 testing functions: functional testing and fault...
-
On degradation of glass/polyester laminate immersed in water
PublicationMechanical behaviour was compared for glass/ polyester laminates manufactured in the boatbuilding plant using three methods: hand lay-up, vacuum bagging, infusion. Specimens were tested in dry condition and following accelerated water immersion test (70°C- corresponding to the exposure of 30 years at 19°C). In three point bending test 40-50% reduction in laminate strength was observed due to water immersion. The highest degradation...
-
total number and biomass of bacteria in drinking water distribution systems.
PublicationIn the vast water supply network using traditional methods of treatment it is often impossible to maintain a constant and acceptable microbiological quality of water. In Poland the main reason of bacterial re-growth is presence of organic matter and nutrients in the circulating water and prolonged water retention in the network systems due to the decrease of water consumption, which has been observed for the last 20 years. In the...
-
Rain Water: Atmospheric Deposition
PublicationWater is transferred from the atmosphere to the land surface mainly via various forms of atmospheric precipitation; however, the contribution of surface condensation/deposition (e.g., dew, hoar frost, occult precipitation) should not be neglected. Rainwater and liquid deposits (dew, hoar frost, rime) are components of the physical and geographical environment that are easily assimilated and transported. Thus, they are generally...
-
Water uptake analysis of acceptor-doped lanthanum orthoniobates
PublicationIn this work, lanthanum orthoniobates doped with either antimony, calcium, or both have been synthesized and studied. The water uptake of the investigated materials has been analyzed by means of thermogravimetric studies. The results show the difference between the thermodynamics of hydration between the lanthanum orthoniobate system and other proton conducting ceramics. The relation between the water uptake and effective acceptor...
-
Fractional neutron point kinetics equations for nuclear reactor dynamics – Numerical solution investigations
PublicationThis paper presents results concerning numerical solutions to a fractional neutron point kinetics model for a nuclear reactor. The paper discusses and expands on results presented in (Espinosa-Paredes et al., 2011). The fractional neutron point kinetics model with six groups of delayed neutron precursors was developed and a numerical solution using the Edwards’ method was proposed (Edwards et al., 2002). The mathematical model...
-
Mechanism of antifreeze protein functioning and the “anchored clathrate water” concept
PublicationIn liquid water, there is a natural tendency to form aggregates that consist of water molecules linked by hydrogen bonds. Such spontaneously formed aggregates are surrounded by a "sea" of disordered water molecules, with both forms remaining in equilibrium. The process of creating water aggregates also takes place in the solvation water of proteins, but in this case the interactions of water molecules with the protein surface shift...
-
POLDER AND CITY: SUSTAINING WATER LANDSCAPES ON AN URBAN EDGE
PublicationThe question investigated in this paper is how to maintain the environmental quality of the polder landscape encompassing the city in the condition of urban pressure on this landscape. On the basis of theoretical approaches, historical surveys and introductory study models new ideas are tested on the case study of Gdansk, a city located in the Vistula River delta in northern Poland. Research shows that the city was created as a...
-
General solution of quantum mechanical equations of motion with time-dependent Hamiltonians: A Lie algebraic approach
PublicationThe unitary operators U(t), describing the quantum time evolution of systems with a time-dependent Hamiltonian, can be constructed in an explicit manner using the method of time-dependent invariants. We clarify the role of Lie-algebraic techniques in this context and elaborate the theory for SU(2) and SU(1,1). In these cases we give explicit formulae for obtaining general solutions from special ones. We show that the constructions...
-
COLD CRACKING OF S460N STEEL WELDED IN WATER ENVIRONMENT
PublicationThis paper shows results of weldability testing of fine-grained high -strength low- alloy S460N steel welded in water environment by covered electrodes. The tests were carried out by using the CTS test specimens with fillet welds. Four specimens were welded under water and one specimen in air. Welded joints were subjected to non-destructive visual and penetration tests. The accepted joints were then subjected to macroscopic and...
-
Analytical solution of non-stationary heat conduction problem for two sliding layers with time-dependent friction conditions
PublicationIn this article we conduct an overview of various types of thermal contact conditions at the sliding interface. We formulate a problem of non-stationary heat conduction in two sliding layers with generalized thermal contact conditions allowing for dependence of the heat-generation coefficient and contact heat transfer coefficient on time. We then derive an analytical solution of the problem by constructing a special coordinate...
-
Analytics of airport runoff water samples
PublicationThe everyday activities at airports, such as aircraft and ground vehicle washing, cleaning, de/anti-icing operations, fuelling, and fuel combustion, removing weeds are the main sources of airport industrial wastes. Runoff waters from airport areas constitute a serious environmental problem as they contribute to air, water, and soil pollution. The paper supplies general information on the technologies for treating airport runoff...
-
The protection and monitoring of a distribution piping network for potable water supply
PublicationPurpose – The purpose of this paper is to implement the corrosion protection method for steel pipes used in a municipal water-pipe network. Results of an inhibitor protection system installed on the system are presented. Inhibitor protection was required due to the high corrosivity of the water collected by a surface intake, which had resulted in a large number of failures and low water quality, due to the presence of corrosion...
-
Chemometrics in monitoring spatial and temporal variations in drinking water quality
PublicationOpracowanie przedstawia wyniki zastosowania wybranych technik chemometrycznych w monitoringu okresowych i powierzchniowych zmian jakości wody pitnej na podstawie wyników oznaczeń chloro i bromopochodnych produktów dezynfekcji wody w 12 dzielnicach w Gdańsku w okresie 1993-2000. Na podstawie wyników analizy podobieństwa lokalizacje podzielono na dwie grupy dzielnic różniących się jakością wody pitnej spowodowanej różnicami wynikającymi...
-
The Effect of Water and Frost on Fatigue Life of Asphalt Concrete
PublicationThis paper presents testing of fatigue life of asphalt concrete that has been subjected to action of water and frost. Simulation of water and frost action was based on the original AASHTO T283 method and its modification. The original method was modified in such a way that instead of a single freeze-thaw cycle, 50 and 150 cycles were applied. Fatigue life was measured in the indirect tensile fatigue test in the Nottingham asphalt...
-
The Application of Granulated Expanded Glass Aggregate with Cement Grout as an Alternative Solution for Sub-Grade and Frost-Protection Sub-Base Layer in Road Construction
PublicationThe purpose of the research was to assess the possibility of using granulated expanded glass aggregate (GEGA) with cement grout as a replacement of a sub-grade and frost-protection layer, made of natural fine aggregates (NATU), stabilized with a hydraulic binder. Instead of traditional parts of the road construction, such as the sub-grade and frost-protection layer with the application of fine aggregate, stabilized with cement,...
-
On Nonlinear Bending Study of a Piezo-Flexomagnetic Nanobeam Based on an Analytical-Numerical Solution
PublicationAmong various magneto-elastic phenomena, flexomagnetic (FM) coupling can be defined as a dependence between strain gradient and magnetic polarization and, contrariwise, elastic strain and magnetic field gradient. This feature is a higher-order one than piezomagnetic, which is the magnetic response to strain. At the nanoscale, where large strain gradients are expected, the FM effect is significant and could be even dominant. In...
-
Exploring Mechanism of Corrosion Inhibition of WE43 and AZ31 Alloys by Aqueous Molybdate in Hank’s Solution by Multisine Impedimetric Monitoring
PublicationThe concept of utilizing multisine dynamic electrochemical impedance spectroscopy to monitor effectiveness of a model molybdate inhibitor for AZ31 and WE43 Mg alloys is proposed. The corrosion kinetics and instantaneous values of inhibition efficiency (IE) of molybdate at concentrations up to 150 mM were examined. The inhibitor provides inhibition in Hank’s solution at concentrations starting from ca. 25 mM, with the IE of about...
-
Nanoparticles and nanofiltration for wastewater treatment: From polluted to fresh water
PublicationWater pollution poses significant threats to both ecosystems and human health. Mitigating this issue requires effective treatment of domestic wastewater to convert waste into bio-fertilizers and gas. Neglecting liquid waste treatment carries severe consequences for health and the environment. This review focuses on intelligent technologies for water and wastewater treatment, targeting waterborne diseases. It covers pollution prevention...
-
Links between Teleconnection Patterns and Water Level Regime of Selected Polish Lakes
Publication -
Mechanism of Biofilm Formation on Installation Materials and Its Impact on the Quality of Tap Water
Publication -
Water and chemical properties of hydrometeors over central european mountains
PublicationAtmospheric pollutants are transferred to the groundby the contribution of various types of hydrometeors. Because ofthe different techniques of measurement, comparative analysesbetween them are often neglected. Hence, the main goal is tocompare water volume and chemistry of different types ofhydrometeors and their role in both: water balance and pollutantsdeposition. The results of water input and atmospheric depositschemistry...
-
On the problem of optimised allocation of water quality sensors and actuators in DWDS
PublicationThe problems of water quality sensors and actuators placement in drinking water distribution systems (DWDSs) are addressed as separate, primarily. However, against the background of control systems theory, the nature of DWDSs dynamics indicates that these both problems are interdependent and impact the design of related water quality monitoring and control structures and algorithms. The research work presented in this paper is...
-
Physicochemical Properties and Application of Silica-Doped Biochar Composites as Efficient Sorbents of Copper from Tap Water
PublicationThis article concerns research on new sorption materials based on silica-doped activated carbon. A two-stage synthesis involved pyrolysis of plant material impregnated in a water glass solution , followed by hydrothermal activation of the pyrolysate in KOH solution. The resulting composite can be used as a sorbent in drinking water filters. The proposed method of synthesis enables the design of materials with a surface area...
-
Experiencing historic waterways and water landscapes of the Vistula River Delta
PublicationThe paper gives insights into the characteristics of Vistula River Delta water landscapes, referring to the process of creating land out of water by Polish, Dutch and German settlers. Based on this, the paper presents an integrated strategy formed upon studies in cultural geography and aesthetics, and focused on enhancing the unique characteristics of the region and its rediscovery by tourism. The long process of constructing Vistula...
-
Fuzzy Sets in the GIS Environment in the Location of Objects on the Surface of Water Bodies
PublicationThe issue presented here focuses on concerns about the localization of the object on water surface. The article shows how to facilitate localization process by applying mathematical solutions characterized by simplicity, rapid action and delivering credible results. The paper shows the results of background experiments, which enabled to collect technical parameters needed for conducting simulation testing. The research has been...
-
Application of membrane distillation process for tap water purification
Publication -
Simplified method of water cooled exhaust system design.
PublicationThe water cooled exhaust systems are not often used onboard ships. Prime goal is to lower temperature of exhaust gas from main propulsion and auxiliary engines to the defined limit. The design of such systems require detailed analysis of propulsion system operational parameters to meet designer expectations. The paper outlines the cooled exhaust system design problems in specific application. The simplified method of evaluation...
-
Dissociation pathways of protonated water clusters
PublicationRelative abundances of positively ionized water clusters formed in a low-pressure electrical discharge as function of reduced electric field were obtained by using drift cell and quadrupole mass spectrometer. It was noticed that some clusters say with n=4 were more abundant than others, at comparable drift conditions. Dissociation energies have been derived from equilibrium conditions for relative clusters abundances. The Hartree-Fock...
-
Guanosine Dianions Hydrated by One to Four Water Molecules
PublicationIntermolecular interactions such as those present in molecule···water complexes may profoundly influence the physicochemical properties of molecules. Here, we carried out an experimental–computational study on doubly deprotonated guanosine monophosphate···water clusters, [dGMP – 2H]2–·nH2O (n = 1–4), using a combination of negative anion photoelectron spectroscopy (NIPES) with molecular dynamics (MD) and quantum chemical (QM) calculations....
-
Impact of diffusion coefficient averaging on solution accuracy of the 2D nonlinear diffusive wave equation for floodplain inundation
PublicationIn the study, the averaging technique of diffusion coefficients in the two-dimensional nonlinear diffusive wave equation applied to the floodplain inundation is presented. As a method of solution, the splitting technique and the modified finite element method with linear shape functions are used. On the stage of spatial integration, it is often assumed that diffusion coefficient is constant over element and equal to its average...
-
Durability of Asphalt Concrete Subjected to Deteriorating Effects of Water and Frost
PublicationThe paper presents testing of the detrimental effects of water and frost on asphalt pavements. It included laboratory testing of 5 fatigue life of asphalt concrete that was subjected to action of water and frost and field testing of damages caused by water and frost on 6 existing asphalt pavements, such as stripping, raveling, and potholes. Laboratory simulation of water and frost action was based on the 7 original AASHTO T283...
-
Sampling Procedures in Studies of Cloud Water Composition: A Review
PublicationThe authors set out and classify the principles of operation of known types of cloud water collectors, and critically review their advantages and drawbacks. Analysis of the literature has yielded information on the parameters of various type of collectors—sampling time, the type of cloud from which the water sample was taken, droplet diameter collected with 50% efficiency (cut off), sample analytes/ parameters determined, types...
-
Water hammer analysis in water supply systems
PublicationPrzedstawiono metodę analizy zjawiska uderzenia hydraulicznego w sieci pierścieniowej. Model matematyczny opisano za pomocą układu równań różniczkowych cząstkowych I stopnia, które przekształcono do układu równań zwyczajnych. Dla rozwiązania układu równań zastosowano metodę predykator-korektor. Podano odpowiednie równania różnicowe dla węzłów złożonych. Przedstawiono przykład obliczeniowy sieci wodociągowej pierścieniowej, składającej...
-
abiotic degradation of chlorinated ethanes and ethenes in water
PublicationIntroduction Chlorinated ethanes and ethenes are among themost frequently detected organic pollutants of water. Theirphysicochemical properties are such that they can contaminateaquifers for decades. In favourable conditions, they canundergo degradation. In anaerobic conditions, chlorinatedsolvents can undergo reductive dechlorination.Degradation pathways Abiotic dechlorination is usuallyslower than microbial but abiotic dechlorination...
-
Theoretical Model of Acoustic Wave Propagation in Shallow Water
PublicationThe work is devoted to the propagation of low frequency waves in a shallow sea. As a source of acoustic waves, underwater disturbances generated by ships were adopted. A specific feature of the propagation of acoustic waves in shallow water is the proximity of boundaries of the limiting media characterised by different impedance properties, which affects the acoustic field coming from a source situated in the water layer “ deformed”...
-
Glass transition temperatures of polyurethane-urea elastomers based on N, N′-ethylenethiourea and N, N′-ethyleneurea as chain extenders
Publication -
Cavitation-Based Processes for Water and Wastewater Treatment
PublicationCavitation based on advanced oxidation processes (Cav-AOPs) is interesting alternatives for already implemented wastewater treatment technologies. Destructive and strongly undesirable phenomena in the industry, i.e., cavitation, revealed to be useful in a positive manner as a source of energy for chemical reactions. During the implosion of cavitation bubbles, focused energy and resulting high temperature and pressure allows to...
-
Dissociation energies of protonated water clusters
PublicationRelative abundances of positively ionized water clusters formed in a low-pressure electrical discharge as function of reduced electric field were obtained by using drift cell and quadrupole mass spectrometer. It was noticed that some clusters say with n = 4 were more abundant than others, at comparable drift conditions. Dissociation energies have been derived from equilibrium conditions for relative clusters abundances. The Hartree-Fock...
-
Implementation of integrated control In drinking water distribution systems - IT system proposal
PublicationImplementation of integrated control algorithms requires suitable hardware and software platforms. Proposed solution must allow realizing control and monitoring tasks, while ensuring high reliability and security of processed data. Additionally, the software and hardware solutions must be immune to outside influence. This paper presents an approach to implementation of control systems in drinking water distribution system. Presented...
-
The influence of water and mineral oil on volumetric losses in a hydraulic motor
PublicationIn this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and comparison. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquid, including water. The sources of leaks in this motor are characterized and described also. On this...
-
DL_MG: A Parallel Multigrid Poisson and Poisson–Boltzmann Solver for Electronic Structure Calculations in Vacuum and Solution
PublicationThe solution of the Poisson equation is a crucial step in electronic structure calculations, yielding the electrostatic potential -- a key component of the quantum mechanical Hamiltonian. In recent decades, theoretical advances and increases in computer performance have made it possible to simulate the electronic structure of extended systems in complex environments. This requires the solution of more complicated variants of the...
-
Synthesis, structural characterization and reactivity of new trisubstituted N1-acylamidrazones: solid state and solution studies
PublicationA series of new linear trisubstituted N1-acylamidrazones have been investigated using a variety of analytical techniques and theoretical calculations to check the influence of the type of N1-acyl substituent on the resonance forms and conformational behavior in the solid state and in solution. The 1D- and 2D-NMR experiments, supported by computational studies, revealed that in solution all amidrazones exhibit conformational syn/anti...
-
AUGMENTATION OF THE CRITICAL HEAT FLUX IN WATER-Al2O3, WATER-TiO2 AND WATER-Cu NANOFLUIDS
PublicationThe main aim of the proposed study is therefore recognition of the phenomena accompanying nucleate boiling crisis of selected nanofluids during boiling on horizontal tubes of various outside diameters. Of particular interest is impact of contact angle and tube diameter on the value of critical heat flux. The results obtained should give more light on the nature of nucleate boiling crisis and will serve as a basis for future theoretical...
-
SESSILE DROPLET CONTACT ANGLE OF WATER-Al2O3, WATER-TiO2 AND WATER-Cu NANOFLUIDS
PublicationThe goal of the present work was the experimental determination of the contact angle of droplets of three nanofluids on various substrates. Of particular interest was effect of nanoparticle concentration on droplet contact angle.
-
Correlated Particle Motion and THz Spectral Response of Supercritical Water
PublicationMolecular dynamics simulations of supercritical water reveal distinctly different distance-dependent modulations of dipolar response and correlations in particle motion compared to ambient conditions. The strongly perturbed H-bond network of water at supercritical conditions allows for considerable translationaland rotational freedom of individual molecules. These changes give rise to substantially different infrared spectra and...
-
Quality Model for Integrated Security Monitoring and Control in Water Distribution Systems
PublicationThis article addresses the problem of drinking water distribution system (DWDS) security in the terms of water quality which in the era of terrorist threat is of high importance to the public. The contribution of this paper is the development of the so called security module to extend a multi-species water quality model. This gives an insight to the situation in DWDS not only under normal operational conditions but also in case...
-
Optimization of hydrodynamic vortex separator for removal of sand particles from storm water by computational fluid dynamics
PublicationStorm water treatment has been gradually acknowledged for the removal of pollutants from urban areas using the hydro cyclone separation technique. The separation efficiency of the hydrodynamic vortex separator (HDVS) is a complex phenomenon. With the aim enhance the separation potency of HDVS for storm runoff to get rid of sand particles, the HDVS with different structural configurations was studied by computational fluid dynamics....
-
Design and Application of Magnetic Photocatalysts for Water Treatment. The Effect of Particle Charge on Surface
PublicationCore-interlayer-shell Fe3O4/SiO2/TiO2, CoFe2O4/SiO2/TiO2 and BaFe12O19/SiO2/TiO2 magnetic photocatalysts were obtained. A water-in-oil microemulsion system with suitable surfactants was used for functionalization of the magnetic core with silica interlayer and TiO2-based photocatalyst. Uncoated and coated particles were characterized by electrophoretic meaurements, X-ray diffractometry (XRD), scanning electron microscopy (SEM),...