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Search results for: WATER TABLE FLUCTUATION
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Water-Lubricated Journal Bearings Marine Applications, Design, and Operational Problems and Solutions
PublicationWater-Lubricated Journal Bearings: Marine Applications, Design, and Operational Problems and Solutions provides cutting-edge design solutions, common problems and methods for avoiding them, and material selection considerations for the use of water-lubricated journal bearings in marine environments. These bearings have many advantages, including the absence of the potential for oil contamination. They are also sensitive, and their...
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Analysis of volatile organic compounds (VOCs) in water samples. Methods and instrumentation
PublicationW pracy przedstawiono stan wiedzy nt. metodyk analitycznych oraz urządzeń kontrolno-pomiarowych, wykorzystywanych w badaniach próbek wody na zawartość lotnych związków organicznych. Szczególną uwagę zwrócono na techniki izolacji i wzbogacania analitów przed etapem oznaczeń końcowych.
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The Application of Electrolysis Method to Disinfect Water Contaminated by Salmonella and Shigella
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Methods of estimating the elements of water balance in a forested catchment basin
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Influence of concentration on contact angle of water-Cu nanofluid on glass substrate
PublicationIn the paper the results of an experimental investigation of influence of nanoparticle concentration on contact angle of water-Cu nanofluid on glass substrate have been presented. Nanoparticles were tested at the concentration of 0.01%, 0.1%, and 1% by weight. In the present study copper was applied as nanoparticle while distilled, deionized water was used as a base fluid. The mean diameter of nanoparticle is estimated to be 50...
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Unusual dynamic properties of water near the ice-binding plane of hyperactive antifreeze protein
PublicationThe dynamical properties of solvation water of hyperactive antifreeze protein from Choristoneura fumiferana (CfAFP) are analyzed and discussed in context of its antifreeze activity. The protein comprises of three well-defined planes and one of them binds to the surface of ice. The dynamical properties of solvation water around each of these planes were analyzed separately; the results are compared with the dynamical properties...
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Influence of sulphate reducing bacteria on water quality in water network
PublicationW pracy zbadano wody podziemne oraz wody rozprowadzane w sieci wodociągowej pod kątem obecności bakterii redukujących siarczany (BRS). Stwierdzono, że BRS były obecne zarówno w wodzie surowej, a także w wodzie uzdatnionej oraz w przewodach sieci wodociągowej.
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Entropy of water calculated from harmonic approximation: estimation of the accuracy of method
PublicationSome molecular dynamics simulations were performed for liquid TIP4P and SPC water at a constant density (1.00 g/cm(3)) and within the temperature range of 5-90 degrees C. By using harmonic approximation, both the entropy of water S-H and the specific heat c(v) were calculated, and the results were compared to literature data. It was found that harmonic approximation overestimates absolute entropy of TIP4P water by 5.6 J/mol K (similar...
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A Comparison of Model Calculations of Ice Thickness with the Observations on Small Water Bodies in Katowice Upland (Southern Poland)
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Biostability of Tap Water—A Qualitative Analysis of Health Risk in the Example of Groundwater Treatment (Semi-Technical Scale)
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Performance of the flat plate solar collector operated with water-Al2O3 nanofluid
PublicationThis paper shows the experimental results of the performance a flat plate solar collector with water-Al2O3 nanofluid as a working fluid. The weight fractions of nanoparticles were 0.1%, 0.2% and 0.4%. The volume flow rate of nanofluid varied from 60 l/h to 170 l/h. The results show that application of nanofluids instead of pure water resulted in higher efficiency of the tested flat plate solar collector for given range of thermal...
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The speciation of organotin compounds in sediment and water samples from the port of Gdynia
PublicationOrganotin compounds (OTC) are toxic towards all living organisms. The application of organitin-based antifouling systems is becoming the main source of OTC in the ocean. Harbor sediments and water contain large deposits of organotin compounds due to application of antifouling systems in the shipping industry. OTC contamination presents a potential risk to the marine environment. Sediment and water samples were collected in 2009...
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Tracking of the broadband source of the underwater noise in the very shallow water conditions
PublicationThe paper contains the result s, both theoretical and experimental , connected with the tracking of the underwater noise source as small ships, pontoon , diver and so on. The pro blem of security in the shallow water area is the challenge for underwater acousticians. In this paper there is take n into account the detection of the sources that move on the surface of the sea or underwater in shallow...
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Influence of Osmolytes on Protein and Water Structure: A Step To Understanding the Mechanism of Protein Stabilization
PublicationResults concerning the thermostability of hen egg white lysozyme in aqueous solutions with stabilizing osmolytes, trimethylamine-N-oxide (TMAO), glycine (Gly), and its N-methyl derivatives, N-methylglycine (NMG), N,N-dimethylglycine (DMG), and N,N,N-trimethylglycine (betaine, TMG), have been presented. The combination of spectroscopic (IR) and calorimetric (DSC) data allowed us to establish a link between osmolytes’ influence on...
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Water-lubricated stern tube bearing - experimental and theoretical investigations of thermal effects
PublicationThe paper presents research results of thermal phenomena accompanying operation of a water-lubricated stern tube bearing with axial grooves. Experimental tests revealed, that intensity of forced axial flow has strong influence on bush temperature. Numerical simulations focused on investigation of the thermal phenomena under operation of water-lubricated journal bearing showed, that restricted axial flow promotes backflow of the...
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Experiment with small objects floating under water in the harbor security aspect.
PublicationObservation of the underwater area is the element of general trend which primary purpose is to protect and enhance the safety of the selected region. The aim of the paper is to present the acoustic characteristics of typical objects floating on the surface or under the water, which constitute some knowledge on how to detect these objects. Create a catalog of acoustic signatures and acoustic images of objects mostly floating under...
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THE 3D MODEL OF WATER SUPPLY NETWORK WITH APPLICATION OF THE ELEVATION DATA
Publication3D visualization is a key element of research and analysis and as the source used by experts in various fields e.g.: experts from water and sewage systems. The aim of this study was to visualize in three-dimensional space model of water supply network with relief. The path of technological development of GESUT data (Geodezyjna Ewidencja Sieci Uzbrojenia Terenu – geodetic records of public utilities) for water supply and measurement...
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An Experimental and Numerical Analysis of Water Hammer Phenomenon in Slurries
PublicationThe analysis of slurry transportation in pressure pipelines is important both from practical and theoretical point of view. Due to the nature of the medium, the number of problems arising in the course of design, operation, measurements and mathematical modeling is much higher compared to the cases where the flowing liquid is homogeneous. The equations describing the flow are more complex, and higher number of the parameters is...
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The impact of the Tri-City Ring Road on surface water of small endorheic wetlands
PublicationThe paper presents the results of the impact of the Tri-City Ring Road on small endorheic catchment basins. Particular attention was paid to pollution discharged from the road to the surface water, as well as changes in hydrological conditions in the vicinity of the road. In the study, surface water samples were analysed in terms of their electrolytic conductivity, pH and content of major minerals. GIS was also used to study transformation...
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How water mediates the long-range interactions between remote protein molecules
PublicationThe high crowding of macromolecules in the cytoplasm affects the processes that occur inside a living cell. It can, for example, promote the forming of various loosely connected structures of proteins. It also means that bulk water is, essentially, not present there. The relatively thin layer of solvent that separates macromolecules may be able to participate in the long-range interactions between them and make them respond to...
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Enhancement of the Brayton cycle efficiency by water or steam utilization
PublicationIn the paper, thermodynamic analysis of two modifications of a Brayton cycle into enhancement cycles with water/steam injection are discussed. The first one deals with a STIG modified system with both interstage compressed air cooling and air heating (heat regeneration) before combustion chamber. The second one, mainly devoted to higher steam/air ratio, is connected with separate steam production in a HRSG. The analysis has been...
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Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
PublicationThis study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break...
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Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
PublicationThis study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break...
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Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
PublicationThis study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break...
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Ecological bearing systems for water turbines – research and development at Gdansk University of Technology
PublicationIncreasing requirements for environmental protection make it necessary to introduce new materials and designs. Hydroelectric power plants operating in direct contact with water reservoirs and rivers are potentially endangering water cleanliness, hence they should also be modernized in the way minimizing the environmental hazards. A lot of progress in this field has been achieved in last decades, but still there is much work to...
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Application of the expanded clay aggregate in form of granular materials for water treatment
PublicationThe paper aimed to evaluate the efficiency of Filtralite MonoMulti compared to the conventional dual-media filter beds comprising silica sand layer covered with anthracite coal. Filtralite media are composed of processed (expanded), highly porous clay products characterized by relatively rough grain surfaces. In order to compare these different media filters in a reliable way, the pilot filter columns operated in parallel, under...
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Water Footprint Assessment of Selected Polymers, Polymer Blends, Composites, and Biocomposites for Industrial Application
PublicationThis paper presents a water footprint assessment of polymers, polymer blends, composites, and biocomposites based on a standardized EUR-pallet case study. The water footprint analysis is based on life cycle assessment (LCA). The study investigates six variants of EUR-pallet production depending on the materials used. The system boundary included the production of each material and the injection molding to obtain a standardized...
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Ancient settlements-atavistic solutions for present water supply and drainage problems engendered by urbanism
PublicationWater is the most valuable resource available on earth. Although it is present in abundance, its usable volume is very scarce. This is the reason behind the existence of both floods and droughts around the world. However, human settlements face water scarcity issues that are primarily engendered by improper town planning measures. To create a balance between the available fractions of water, it is therefore imperative to have proper...
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Modal analysis of a fish-belly flap type of steel water gate
PublicationABSTRACT: The results of a modal analysis of the fish-belly flap type of steel water gate are presented in the paper. The analysis was conducted for a detailed numerical model of the structure using four-node quadrilateral shell elements. The study was focused on the examination of the influence of positioning of the flap gate and hydrostatic pressure of water on the eigenvalues and eigenmodes of the structure. The results of the study...
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Experimental investigation of forced convection of water-Al2O3 nanofluids inside horizontal tubes,
PublicationIn this paper, forced convection of water–Al2O3 nanofluids inside horizontal copper tube is studied experimentally. Experiments were conducted for three, i.e. 0.1%, 1% and 5% nanoparticle mass concentrations under transition and turbulent flow regimes. Average heat transfer coefficients and pressure drop values were determined and compared to distilled water. Enhancement of heat transfer for lower nanoparticle concentration and...
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Case study of water vapour transmission properties of EPDM façade membranes
PublicationThis research aimed to investigate the water vapour transmission properties of chosen EPDM membranes applied in façade and window systems under laboratory tests. The applied procedure included in national and international standards utilized for the laboratory tests of water vapour transmission properties of EPDM membrane is described. Two main types (outside and inside types) of EPDM membranes are laboratory tested. The authors...
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The Use of Cluster Analysis to Evaluate the Impact of COVID-19 Pandemic on Daily Water Demand Patterns
PublicationProper determination of unitary water demand and diurnal distribution of water consumption (water consumption histogram) provides the basis for designing, dimensioning, and all analyses of water supply networks. It is important in the case of mathematical modelling of flows in the water supply network, particularly during the determination of nodal water demands in the context of Extended Period Simulation (EPS). Considering the...
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A role of an Enterprise Identification Card in a building process of water tourist investments
PublicationAn essential element of a building process for water tourist investments in Poland is a document called the Enterprise Identification Card. It is required for the investments, which are classified according to the Regulation [1] as the ones that could potentially impact the environment. It is assumed that KIP is there to protect the environment against the excessive human interference and it just provides the guidelines regarding...
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Simulations of air and water flow in a model dike during overflow experiments
PublicationFlow in flood dikes, earth dams, and embankments occurs in variably saturated conditions, with pores of the earth material filled partly with water and partly with air. In routine engineering analysis, the influence of pore air is neglected and the air pressure is assumed equal to atmospheric. In some circumstances, for example, during overtopping of the dike by water, the effect of pore air on water flow and stability of the structure...
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Carbon Dioxide and Water Vapour Fluxes of a Alkaline Fen and Their Dependence on Reflectance
PublicationThis study shows results of parallel measurements of greenhouse gases fluxes (carbon dioxide and water vapour) and canopy reflectance of alkaline fen. Fluxes were measured using eddy-covariance technique on micrometeorological station located in the Upper Biebrza Basin (NE Poland) in Rogożynek Village. Study site is located in the Biebrza National Park which was established to protect one of the biggest coherent lowland wetland...
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Leakage detection and localisation in drinking water distributionnetworks by MultiRegional PCA
PublicationMonitoring is one of the most important steps in advanced control of complex dynamic systems. Precise information about systems behaviour, including faults indicating, enables for efficient control. The paper describes an approach to detection and localisation of pipe leakage in Drinking Water Distribution Systems (DWDS) representing complex and distributed dynamic system of large scale. Proposed MultiRegional Principal Component...
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The PolarScreen™ Estrogen Receptor Competitor Assays for determination of estradiol equivalent concentrations (EEQs) in sewage and drinking water samples.
Open Research DataMunicipal 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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Comparison of state feedback and PID control of pressurizer water level in nuclear power plant
PublicationThe pressurizer water level control system in nuclear power plant with pressurized water reactor (PWR) is responsible for coolant mass balance. The main control goal is to stabilize the water level at a reference value and to suppress the effect of time-varying disturbances (e.g. coolant leakage in primary circuit pipeline system). In the process of PWR power plant operation incorrect water level may disturb pressure control or...
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Balance errors in numerical solutions of shallow water equations
PublicationThe analysis of the conservative properties of the shallow water equations is presented in the paper. The work focuses on the consistency of numerical solution of these equations with the conservation laws of mass and momentum. The investigations involve two different conservative forms which are solved by an implicit box scheme. The theoretical analysis supported by numerical experiments is carried out for rectangular channel...
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Elastic scattering of electrons by water: An ab initio study
PublicationIn this work we devise a theoretical and computational method to compute the elastic scattering of electrons from a non-spherical potential, such as in the case of molecules and molecular aggregates. Its main feature is represented by the ability of calculating accurate wave functions for continuum states of polycentric systems via the solution of the Lippmann-Schwinger equation, including both the correlation effects and multi-scattering...
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Hyperbranched polyethylenimine functionalized silica/polysulfone nanocomposite membranes for water purification
PublicationHyperbranched polyethyleneimine functionalized silica (PEI-SiO2) nanoparticles with considerable hydrophilicity were synthesized and incorporated into a polysulfone (PSF)/dimethylacetamide (DMA)/polyvinylpyrrolidone (PVP) membrane casting solution in five different ratios to fabricate PEI-SiO2/PSF nanocomposite membranes using nonsolvent-induced phase separation. The hydrophilic PEI-SiO2 nanoparticles were characterized by TEM,...
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Solubility of carbon dioxide in water: Some useful results for hydrate nucleation
PublicationIn this paper, the solubility of carbon dioxide (CO2) in water along the isobar of 400 bar is determined by computer simulations using the well-known TIP4P/Ice force field for water and the TraPPE model for CO2. In particular, the solubility of CO2 in water when in contact with the CO2 liquid phase and the solubility of CO2 in water when in contact with the hydrate have been determined. The solubility of CO2 in a liquid–liquid...
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Analyzing the Impact of Simulated Multispectral Images on Water Classification Accuracy by Means of Spectral Characteristics
PublicationRemote sensing is widely applied in examining the parameters of the state and quality of water. Spectral characteristics of water are strictly connected with the dispersion of electromagnetic radiation by suspended matter and the absorp-tion of radiation by water and chlorophyll a and b.Multispectral sensor ALI has bands within the ranges of electromagnetic radia-tion: blue and infrared, absent in sensors such as Landsat, SPOT,...
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Bismuth-based nanomaterials-assisted photocatalytic water splitting for sustainable hydrogen production
PublicationThe rapidly increase in the world's population has resulted in a corresponding increase in the energy demand. This demand is largely being met by fossil fuels for power generation, industrial fuel and transportation. However, due to the limited availability of fossil fuels and their negative effects on the environment. The use of fossil fuels results in by-products such as carbon, nitrogen and sulfur oxides which have negative...
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Bismuth-based nanomaterials-assisted photocatalytic water splitting for sustainable hydrogen production
PublicationThe rapidly increase in the world's population has resulted in a corresponding increase in the energy demand. This demand is largely being met by fossil fuels for power generation, industrial fuel and transportation. However, due to the limited availability of fossil fuels and their negative effects on the environment. The use of fossil fuels results in by-products such as carbon, nitrogen and sulfur oxides which have negative...
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Shallow-Water Acoustic Communications in Strong Multipath Propagation Conditions
PublicationA phenomenon that has a strong impact on signal transmission conditions in Underwater Acoustic Communication (UAC) systems is multipath propagation. As a result of multipath propagation, the transmitted signal undergoes time dispersion which results in inter-symbol interference observed on the receiving side. Time dispersion is large, especially in horizontal channels in shallow waters which significantly limits the transmission...
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Shipping Low Frequency Noise and Its Propagation in Shallow Water
PublicationOne of the most significant factor influencing acoustical climate of the sea is underwater noise generated by moving ships. If the considered sea area has features of the shallow water, namely the wave frequency fulfils relation f < 10c/h, where c denotes phase speed of sound, and h is depths of the sea, then in certain distance from the wave source specific image of sound pressure distribution in the mean of wave modes appears....
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Determination of metals in water samples by atomic absorption spectrometry and flame emission spectrometry
PublicationMetal species in environmental waters are relevant to characterize the metal toxicity, the mobility between different environmental compartments, and for remediation purposes in case of contamination. The concentration of many trace metals in natural water samples are generally at µg/l level. The paper describes determination of metals in water samples based on flame atomic emission and flame atomic absorption spectrometry.
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The importance of the shape of the protein-water interface of a kinesin motor domain for dynamics of the surface atoms of the protein
PublicationSingle kinesin motor domain immersed in water has been investigated using molecular dynamics. It has been found that local properties of water in solvation shell change along with the nature of neighboring protein surface. However, a detailed analysis leads to the conclusion that the geometrical features of hydrogen bonds and overall structure of kinesin hydration water is not very different from bulk water. The local values of...
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The importance of the shape of the protein–water interface of a kinesin motor domain for dynamics of the surface atoms of the protein
PublicationA single kinesin motor domain immersed in water has been investigated using molecular dynamics. It has been found that local properties of water in the solvation shell change along with the nature of the neighboring protein surface. However, a detailed analysis leads to the conclusion that the geometrical features of hydrogen bonds and overall structure of kinesin hydration water are not very different from bulk water. The local...