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Search results for: EXISTENCE OF POSITIVE SOLUTIONS
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Crystal Structure, Antioxidant Properties and Characteristics in Aqueous Solutions of the Oxidovanadium(IV) Complex [VO(IDA)phen]·2H2O
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Aeration Process in Bioreactors as the Main Energy Consumer in a Wastewater Treatment Plant. Review of Solutions and Methods of Process Optimization
PublicationDue to the key role of the biological decomposition process of organic compounds in wastewater treatment, a very important thing is appropriate aeration of activated sludge, because microorganisms have to be supplied with an appropriate amount of oxygen. Aeration is one of the most energy-consuming processes in the conventional activated sludge systems of wastewater treatment technology (may consume from 50% to 90% of electricity...
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Vivedenna dosovih vod u grunt = The rain - water management solutions basedon the seepage phenomena cz.2
PublicationWprowadzanie wód opadowych do gruntu. Rozwiązania o dużej przepustowości, do użycia w odwadnianiu dużych powierzchni.
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Boundary problems for fractional differential equations
PublicationIn this paper, the existence of solutions of fractional differential equations with nonlinear boundary conditions is investigated. The monotone iterative method combined with lower and upper solutions is applied. Fractional differential inequalities are also discussed. Two examples are added to illustrate the results.
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Structured populations with diffusion and Feller conditions
PublicationWe prove a weak maximum principle for structured population models with dynamic boundary conditions. We establish existence and positivity of solutions of these models and investigate the asymptotic behaviour of solutions. In particular, we analyse so called size profile.
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The preparation and evaluation of core-shell magnetic dummy-template molecularly imprinted polymers for preliminary recognition of the low-mass polybrominated diphenyl ethers from aqueous solutions
PublicationThe design, preparation process, binding abilities, morphological characteristic and prospective field of application of dummy-template magnetic molecularly imprinted polymer (DMMIP) for preliminary recognition of the selected low-mass polybrominated diphenyl ethers (PBDE-47 and PBDE-99) from aquatic environment were investigated. The surface of iron oxide (Fe3O4) nanopowder (50-100 nm particles size) was modified with tetraethoxysilane...
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Parabolic Equations with Functional Dependence
PublicationWe consider the Cauchy problem for nonlinear parabolic equations with functional dependence and prove theorems on the existence of solutions to parabolic differential-functional equations.
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Nonnegative solutions to nonlocal boundary value problems for systems of second-order differential equations dependent on the first-order derivatives
PublicationStosując tw. Avery-Petersona o punkcie stałym, podano warunki dostateczne na istnienie nieujemnych rozwiązań dla układów równań różniczkowych rzędu drugiego z argumentami opóźnionymi i wyprzedzonymi oraz warunkami brzegowymi zawierającymi całki Stieltjesa. Praca zawiera wiele przykładów.
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Thermodynamics and Intermolecular Interactions of Nicotinamide in Neat and Binary Solutions: Experimental Measurements and COSMO-RS Concentration Dependent Reactions Investigations
PublicationIn this study, the temperature-dependent solubility of nicotinamide (niacin) was measured in six neat solvents and five aqueous-organic binary mixtures (methanol, 1,4-dioxane, acetonitrile, DMSO and DMF). It was discovered that the selected set of organic solvents offer all sorts of solvent effects, including co-solvent, synergistic, and anti-solvent features, enabling flexible tuning of niacin solubility. In addition, differential...
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Application of hollow mesoporous carbon nanospheres as an high effective adsorbent for the fast removal of acid dyes from aqueous solutions
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Investigations of ternary complexes of Co(II) and Ni(II) with thiodiacetate anion and 1,10-phenanthroline or 2,2’-bipyridine in aqueous solutions
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Improved adsorption performance of activated carbon covalently functionalised with sulphur-containing ligands in the removal of cadmium from aqueous solutions
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Carbon Fibers Obtained from Flax and Their Adsorption Performance in the Removal of Cu(II) and Co(II) from Aqueous Solutions
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How high-tech solutions support the fight against IUU and ghost fishing: a review of innovative approaches, methods, and trends
PublicationIllegal, Unreported, and Unregulated fishing is a major threat to human food supply and marine ecosystem health. Not only is it a cause of significant economic loss but also its effects have serious long-term environmental implications, such as overfishing and ocean pollution. The beginning of the fight against this problem dates since the early 2000s. From that time, a number of approaches and methods have been developed and reported....
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SOLUTIONS OF THE INTERMEDIATE SUPPORT STRUC- TURES OF THE NORTHERN MARMARA HIGHWAY (ISTAN- BUL’S RING ROAD) IN THE CONTEXT OF SEISMIC ACTIVITY
PublicationIn 2014–2018, as a result of the expansion of the city of Istanbul in Turkey, a project was imple- mented consisting of building a northern ring road, called the Northern Marmara Highway. The concept of the structural design of the ring road’s intermediate supports aims at constructing sup- ports that according to the TURKISH DLH 2008 standard must comply with the design require- ments for the three calculated earthquake insensitivity...
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Architectural and Urban Planning Solutions for the Protection of Heritage Buildings in the Context of Terrorist Attacks: Following the Example of Passive Protection Systems
PublicationEvents in recent years showing numerous terrorist attacks raise awareness regarding the neces-sity of considering the safety of heritage buildings. The analysis of available data allows us to conclude that it is not possible to fully prevent terrorist attacks. On the other hand, it is possible to minimize the impact of such incidents through proper design of Passive Protection System (PPS) components. One possible architectural...
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Homoclinic orbits for an almost periodically forced singular Newtonian system in R^3
Publication. This work uses a variational approach to establish the existence of at least two homoclinic solutions for a family of singular Newtonian systems in R^3 which are subjected to almost periodic forcing in time variable
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Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part II: Gas-chromatography–mass spectrometry analysis
PublicationFlavouring compounds are an essential part of e-liquid products for cigarettes. In general, they are regarded as safe for ingestion, but they may have unrecognized risks when they are inhaled. In some cases, manufactures do not currently abide by the Tobacco Products Directive (2014/40/EU) and do not declare the detailed contents of e-liquids on their labels. To help evaluate the health impact of flavouring substances, there is...
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Efficiency of ozonation process with calcium peroxide in removing heavy metals (Pb, Cu, Zn, Ni, Cd) from aqueous solutions
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Study on efficient removal of anionic, cationic and nonionic dyes from aqueous solutions by means of mesoporous carbon nanospheres with empty cavity
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Testing the positioning accuracy of GNSS solutions during the tramway track mobile satellite measurements in diverse urban signal reception conditions
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Testing the Positioning Accuracy of GNSS Solutions during the Tramway Track Mobile Satellite Measurements in Diverse Urban Signal Reception Conditions
PublicationMobile Global Navigation Satellite System (GNSS) measurements carried out on the railway consist of using satellite navigation systems to determine the track geometry of a moving railway vehicle on a given route. Their purposes include diagnostics, stocktaking, and design work in railways. The greatest advantage of this method is the ability to perform measurements in a unified and coherent spatial reference system, which...
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Fractional problems with advanced arguments
PublicationThis paper concerns boundary fractional differential problems with advanced arguments. We investigate the existence of initial value problems when the initial point is given at the end point of an interval. Nonhomogeneous linear fractional differential equations are also studied. The existence of solutions for fractional differential equations with advanced arguments and with boundary value problems has been investigated by using...
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Rothe’s method for physiologically structured models with diffusion
PublicationWe consider structured population models with diffusion and dynamic boundary conditions. The respective approximation, called Rothe’s method, produces positive and exponentially bounded solutions. Its solutions converge to the exact solution of the original PDE.
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Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part I: Liquid chromatography-tandem mass spectrometry analysis
PublicationLiquid chromatography-tandem mass spectrometry with electrospray ionization (HPLC-ESI–MS/MS) methods were developed for the simultaneous determination of 42 flavouring compounds and nicotine in liquids for e-cigarettes. The chromatographic separation was performed using an Ace® Ultracore™ SuperC18™ (100 × 2.1 mm, 2.5 μm) column in both acidic and alkaline pH conditions to separate all the compounds. A simple “dilute & shoot” approach...
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Development of direct-current, atmospheric-pressure, glow discharges generated in contact with flowing electrolyte solutions for elemental analysis by optical emission spectrometry
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Mangiferin and Hesperidin Transdermal Distribution and Permeability through the Skin from Solutions and Honeybush Extracts (Cyclopia sp.)—A Comparison Ex Vivo Study
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Magnetic Molecularly Imprinted Polymer Nanoparticles for Selective Extraction of Copper from Aqueous Solutions Prior to Its Flame Atomic Absorption Determination
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Magnetic molecularly imprinted polymer nanoparticles for selective extraction of copper from aqueous solutions prior to its flame atomic absorption determination
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Kinetics and thermodynamics of the reaction of iminodiacetate copper(II) complexes with 1,10-phenanthroline and 2,2′-bipyridine in aqueous, anionic, cationic and nonionic surfactants solutions
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Urban space recovery. Landscape-beneficial solutions in new estates built in post-industrial and post-military areas in Bristol, Poznań and Gdańsk
PublicationThe limitation of territorial expansion and the implementation of the idea of a compact city are generally accepted paradigms of spatial development of contemporary cities. In consequence, actions are taken to improve the quality of city landscape and revitalise vacant areas. This study approaches the process of city regeneration as transformation and supplementation of the existing urban structure as well as creation of multifunctional, structurally,...
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Practical Approach to Large-Scale Electronic Structure Calculations in Electrolyte Solutions via Continuum-Embedded Linear-Scaling Density Functional Theory
PublicationWe present the implementation of a hybrid continuum-atomistic model for including the effects of a surrounding electrolyte in large-scale density functional theory (DFT) calculations within the Order-N Electronic Total Energy Package (ONETEP) linear-scaling DFT code, which allows the simulation of large complex systems such as electrochemical interfaces. The model represents the electrolyte ions as a scalar field and the solvent...
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Volumetric and acoustic properties of D-mannitol in aqueous sodium or magnesium(II) chloride solutions over temperature range of 293.15 to 313.15 K
PublicationWykorzystując zmierzone wartości gęstości oraz prędkości rozchodzenia się dźwięku wyznaczono pozorne objętości molowe i pozorne ściśliwości molowe D- mannitolu w (1, 5 i 10) % wodnych roztworach chlorku sodu oraz chlorku magnezu(II). Obliczono graniczne wartości pozornych wielkości molowych, odpowiednie funkcje przeniesienia oraz współczynniki rozszerzalności. Otrzymane wielkości powiązano z oddziaływaniami D-mannitol -sól (NaCl...
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Synthesis of Cyano-Benzylidene Xanthene Synthons Using a Diprotic Brønsted Acid Catalyst, and Their Application as Efficient Inhibitors of Aluminum Corrosion in Alkaline Solutions
PublicationNovel cyano-benzylidene xanthene derivatives were synthesized using one-pot and condensation reactions. A diprotic Brønsted acid (i.e., oxalic acid) was used as an effective catalyst for the promotion of the synthesis process of the new starting xanthene–aldehyde compound. Different xanthene concentrations (ca. 0.1–2.0 mM) were applied as corrosion inhibitors to control the alkaline uniform corrosion of aluminum. Measurements were...
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Fractional differential equations with causal operators
PublicationWe study fractional differential equations with causal operators. The existence of solutions is obtained by applying the successive approximate method. Some applications are discussed including also the case when causal operator Q is a linear operator. Examples illustrate some results.
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First-order differential equations with nonlocal boundary conditions
PublicationWe study a first-order boundary value problem subject to some boundary conditions given by Riemann-Stieltjes integrals. Using a monotone iterative method, we formulate sufficient conditions which guarantee the existence of extremal or quasi-solutions in the corresponding region bounded by upper and lower solutions of our problems. The case when a unique solution exists is also investigated. Some examples are given to illustrate...
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Homoclinic and Heteroclinic Orbits for a Class of Singular Planar Newtonian Systems
PublicationThe study of existence and multiplicity of solutions of differential equations possessing a variational nature is a problem of great meaning since most of them derives from mechanics and physics. In particular, this relates to Hamiltonian systems including Newtonian ones. During the past thirty years there has been a great deal of progress in the use of variational methods to find periodic, homoclinic and heteroclinic solutions...
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N,N’-Bis(salicylidene)ethylenediamine (Salen) as an Active Compound for the Recovery of Ni(II), Cu(II), and Zn(II) Ions from Aqueous Solutions
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A study of the structure of mixed micellar solutions based on heptaethylene glycol monotetradecyl ether and sodium (lithium) dodecyl sulfate by the small-angle neutron scattering method
PublicationZbadano micelizację w układach mieszanych bazujących na nowym surfaktancie niejonowym, heptaoksyetylenowanym alkoholu tetradecylowym (C14E7) i surfaktantach anionowych, dodecylosiarczanie sodu, decylosiarcznie sodu oraz dodecylosiarcznie litu za pomocą metody niskokątowego rozproszenia neutronów.Przedstawione zostały wstępne wyniki zachowania wodnych roztworów C14E7 (o dwóch stężeniach 0,17 i 0,50%) przy niewielkim udziale trzech...
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The effect of strain rate on the passive layer cracking of 304L stainless steel in chloride solutions based on the differential analysis of electrochemical parameters obtained by means of DEIS
PublicationOkreślono wpływ szybkości rozciągania w zakresie 10-5s-1 ÷ 16∙10-5s-1 na niestacjonarny proces elektrochemiczny pękania warstwy pasywnej. Badania przeprowadzono na stali wysokostopowej 304L w temperaturze pokojowej w środowisku chlorków za pomocą dynamicznej elektrochemicznej spektroskopii impedancyjnej (DEIS). W rezultacie uzyskano zestaw chwilowych widm impedancyjnych odzwierciedlających dynamikę badanego układu korozyjnego....
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On Solvability of Boundary Value Problems for Elastic Micropolar Shells with Rigid Inclusions
PublicationIn the framework of the linear theory of micropolar shells, existence and uniqueness theorems for weak solutions of boundary value problems describing small deformations of elastic micropolar shells connected to a system of absolutely rigid bodies are proved. The definition of a weak solution is based on the principle of virial movements. A feature of this problem is non-standard boundary conditions at the interface between the...
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TRAVELLING WAVES FOR LOW–GRADE GLIOMA GROWTH AND RESPONSE TO A CHEMOTHERAPY MODEL
PublicationLow-grade gliomas (LGGs) are primary brain tumours which evolve very slowly in time, but inevitably cause patient death. In this paper, we consider a PDE version of the previously proposed ODE model that describes the changes in the densities of functionally alive LGGs cells and cells that are irreversibly damaged by chemotherapy treatment. Besides the basic mathematical properties of the model, we study the possibility of the...
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A strategy for GPS data processing in a precise local network during high solar activity
PublicationThis paper presents the analyses connected with reduction of errors from ionospheric refraction using GPS data from local satellite networks. This is particularly essential during rising solar activity. The Bernese GPS Software v. 4.2 was used, as an analytical tool. The test data included measurements from a geodynamic network SUDETES situated in the Sudety Mountains across the border between the Czech Republic and Poland. A local...
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Relationship between GIX, SIDX, and ROTI ionospheric indices and GNSS precise positioning results under geomagnetic storms
PublicationIonospheric indices give information about ionospheric perturbations, which may cause absorption, diffraction, refraction, and scattering of radio signals, including those from global navigation satellite systems (GNSS). Therefore, there may be a relationship between index values and GNSS positioning results. A thorough understanding of ionospheric indices and their relationship to positioning results can help monitor and forecast...
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Wykonanie instalacji elektrycznej a jakość energii elektrycznej. - Tł. z Plant Engineering. - Tyt. oryg.: Driving electrical reliability in power quality solutions / Mike Johnson
PublicationW arytukule przedstawiono rozwiązania techniczne instalacji elektrycznej poprawiające jakość energii elektrycznej. Podano charakterystykę urządzeń ograniczających przepięcia i zapewniających bezprzerwowe zasilanie odbiorników enetrgii elektrycznej.
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Recent advances in the recovery of precious metals (Au, Ag, Pd) from acidic and WEEE solutions by solvent extraction and polymer inclusion membrane processes – a mini-review
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Homoclinic orbits for a class of singular second order Hamiltonian systems in ℝ3
PublicationWe consider a conservative second order Hamiltonian system \ddot{q}+ ∇V(q)=0 in R3 with a potential V having a global maximum at the origin and a line l ∩ {0} = ∅ as a set of singular points. Under a certain compactness condition on V at infinity and a strong force condition at singular points we study, by the use of variational methods and geometrical arguments, the existence of homoclinic solutions of the system.
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Clarke duality for Hamiltonian systems with nonstandard growth
PublicationWe consider the existence of periodic solutions to Hamiltonian systems with growth conditions involving G-function. We introduce the notion of symplectic G-function and provide relation for the growth of Hamiltonian in terms of certain constant CG associated to symplectic G-function G. We discuss an optimality of this constant for some special cases. We also provide applications to the Φ-laplacian type systems.
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Two families of infinitely many homoclinics for singular strong force Hamiltonian systems
PublicationWe are concerned with a planar autonomous Hamiltonian system with a potential possessing a single well of infinite depth at a point X and a unique strict global maximum 0 at a point A. Under a strong force condition around the singularity X, via minimization of an action integral and using a shadowing chain lemma together with simple geometrical arguments, we prove the existence of infinitely many geometrically distinct homoclinic...
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GPS-derived height changes in diurnal and sub-diurnal timescales
PublicationThis paper describes the research concerning precise short-time GPS solutions conducted in the Centre of Applied Geomatics, Military University of Technology, Warsaw, Poland. The data from ASG-EUPOS (Polish Active Geodetic Network) was processed using Bernese 5.0 software and EPN (EUREF Permanent Network) standards and models. In this study, the adapted 3-hour observation window is shifted every hour for obtaining hourly geocentric...