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Search results for: VOID FRACTION
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Closed forms of the Green's function and the generalized Green's function for the Helmholtz operator on the N-dimensional unit sphere
PublicationPokazano, że funkcję Greena dla operatora Helmholtza na N-wymiarowej sferze jednostkowej można wyrazić przez funcję Gegenbauera pierwszego rodzaju. W tych przypadkach, w których funkcja Greena nie istnieje, skonstruowano uogólnioną funkcję Greena.
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On the reaction of bis(phosphothioyl)disulfanes with hydroxamic acids, part I: Ionic versus radical reaction pathways
PublicationReaktywność disulfanów bisfosforotiowych jest mało poznana. Wiadomo, że wykazują one aktywność pestycydową związaną z inhibicją acetylocholinesterazy. Z kolei, kwasy hydroksamowe stosuje się jako efektywne środki do detoksykacji trucizn fosforoorganicznych. Zbadano reakcje soli kwasów benzohydroksamowych z elektrofilowymi disulfanami bisfosfonotiowymi. Badania prowadzono z użyciem disulfanów bisfosforo-, bisfosfono- i bisfosfinotiowych....
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Recurrence scheme for FDTD-compatible discrete Green's function derived based on properties of Gauss hypergeometric function
PublicationIn this paper, the formulation of one-dimensional FDTD (Finite-difference time-domain)-compatible discrete Green's function (DGF) is derived based on the Gauss hypergeometric function (GHF). The properties of GHF make it possible to derive the recurrence scheme only in the time domain for the DGF generation. Furthermore, this recurrence scheme is valid for any stable time-step size and can be implemented using standard numerical...
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Critique - Studies in Contemporary Fiction
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Science Fiction Film and Television
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Short Fiction in Theory and Practice
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Sliding friction of alumina (Al2O3) with friction induced vibrations
Open Research DataTest files containing data on experiments in self mated sliding contact of alumina Al2O3 lubricated with either water or paraffin oil. Tests run in variable load/velocity conditions and with different dynamic settings of the test rig (PT-3 tribometer). The aim of the research was to attempt in finding correlations between the dynamic characteristics...
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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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Some applications of fractional order calculus
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Fractional Order Models of Dynamic Systems
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Optimal Control for Discrete Fractional Systems
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N-(diphenoxyphosphoryl)succinimide:synthesis and reaction with alkoxides
PublicationReakcja sukcynoimidu z chlorkiem difenylofosforowym w obecności lda a prowadzi do powstania amidofosforanu. ta sama reakcja prowadzona w obecności wodorku sodu pozwala na otrzymanie fosforylowanego sukcynoimidu, który w reakcji z alkoholanami w nasteptwie otwarcia pierścienia, prowadzi do do analogów amidofosforanu z dobrymi wydajnościami.
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Fractional differential equations with deviating arguments
PublicationDla równań różniczkowych typu ułamkowego, zostały podane warunki dostateczne na istnienie jednego rozwiązania lub rozwiazań ekstremalnych. Nierówności różniczkowe są też doskutowane.
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On Applications of Fractional Derivatives in Electromagnetic Theory
PublicationIn this paper, concepts of fractional-order (FO) derivatives are analysed from the point of view of applications in the electromagnetic theory. The mathematical problems related to the FO generalization of Maxwell's equations are investigated. The most popular formulations of the fractional derivatives, i.e., Riemann-Liouville, Caputo, Grünwald-Letnikov and Marchaud definitions, are considered. Properties of these derivatives are...
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Fractional Order Dynamic Positioning Controller
PublicationImproving the performance of Dynamic Positioning System in such applications as station keeping, position mooring and slow speed references tracking requires improving the position and heading control precision. These goals can be achieved through the improvement of the ship control system. Fractional-order calculus is a very useful tool which extends classical, integer-order calculus and is used in contemporary modeling and control...
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Acceleration of the discrete Green's function computations
PublicationResults of the acceleration of the 3-D discrete Green's function (DGF) computations on the multicore processor are presented. The code was developed in the multiple precision arithmetic with use of the OpenMP parallel programming interface. As a result, the speedup factor of three orders of magnitude compared to the previous implementation was obtained thus applicability of the DGF in FDTD simulations was significantly improved.
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Accuracy of the discrete Green's function computations
PublicationThis paper discusses the accuracy of the discrete Green's function (DGF) computations. Recently closed-form expression of the DGF and its efficient numerical implementation were presented which facilitate the DGF applications in FDTD simulations of radiation and scattering problems. By carefully comparing the DGF results to those of the FDTD simulation, one can make conclusions about the range of the applicability of the DGF for...
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On Applications of Fractional Derivatives in Circuit Theory
PublicationIn this paper, concepts of fractional-order (FO) derivatives are discussed from the point of view of applications in the circuit theory. The properties of FO derivatives required for the circuit-level modelling are formulated. Potential problems related to the generalization of transmission line equations with the use of FO derivatives are presented. It is demonstrated that some of formulations of the FO derivatives have limited...
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A procedure for elastoplastic hardening function identification.
PublicationThe inverse analysis method for identifying a nonlinear hardening function,which governs a plastic yielding of soil and rock materials in the framework of elastoplastic theory is presented. A concept of two stage finite element based on spatial discretization of computational space and hardening function space is introduced. The proposed inverse analysis can be classified as the output least squares method. The Levenberg Marquard...
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Load function walking pedestrian on the footbridge.
PublicationModern foot bridges are more and more sensitive to variable load created by moving pedestrians. These are several reasons for that. Quickly growing up road infrastructure forces us to build foot bridges just to reconnect one piece of land, separated now by the new road or railway. These bridges are lightweight because the only live load acting on them comes from pedestrians.The paper focuses on the definition of human induces dynamic...
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Systems of Nonlinear Fractional Differential Equations
PublicationUsing the iterative method, this paper investigates the existence of a unique solution to systems of nonlinear fractional differential equations, which involve the right-handed Riemann-Liouville fractional derivatives D(T)(q)x and D(T)(q)y. Systems of linear fractional differential equations are also discussed. Two examples are added to illustrate the results.
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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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Action Plan “Women”
PublicationEmployees of a company are not the first alternative coming into one’s mind when searching suitable successor for the business. Those belonging to the company’s management group are in many cases asked for their interest in being a successor, but the lower level an employee is in the hierarchy, the less probably he/she is inquired of his/her interest in becoming a successor. The contemporary entrepreneur may have had conflicts...
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Phytochemical Profiling and Larval Control of Erythrina variegata Methanol Fraction against Malarial and Filarial Vector
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Hydroacoustic System in a Biomimetic Underwater Vehicle to Avoid Collision with Vessels with Low-Speed Propellers in a Controlled Environment
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Rola protokołu MEGACO/H.248 w telefonii internetowej VoIP i sieciach następnej generacji
PublicationWzrost znaczenia technologii telefonii internetowej VoIP oraz wzrost ilości danych multimedialnych przesyłanych przez sieci pakietowe IP powoduje, że dotychczasowe rozwiązania, takie jak H.323 czy SIP, przestają być wystarczające. Aby sprostać nowym wymaganiom potrzebny jest nowy sposób (protokół) zarządzania i sterowania ruchem danych, który jednocześnie zgodny będzie z wymaganiami stawianymi przez sieci następnej generacji -...
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Influence of nitrogen and organic matter fractions on wastewater treatment in treatment wetland
PublicationMunicipal wastewater contains both biodegradable and non-degradable pollutants. Moreover, they are present in dissolved, colloidal and particulate forms. These fractions are characterised by various decomposition rates, hence their bioavailability during microbial respiration. It was confirm that biological degradation rate in terms of COD reduction is influenced by particle size speciation. Therefore, the objective of the study...
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Automated Diagnostics of Current Pick-Up Disturbances in Electric Traction Networks
PublicationThe present work defines the basic causes of bow disturbances of current pick-up, sets a task of establishing a system of automated control of bow disturbances at feeder zones of electric traction networks, proposes structural variants of the technical system implementation, describes the algorithm of detection of bow disturbances of current pick-up.
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Determination of bisphenol A in size fractions of indoor dust from several microenvironments
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A new concept of measuring the friction forces for cartilage and polymers with viscoelastic properties
PublicationReferat przedstawia nową koncepcję dotyczącą pomiaru niskich sił tarcia oraz właściwości materiałów lepkosprężystych. Zaprezentowano: ogólny zarys metody pomiaru, wskazania dotyczące projektowania i budowy urządzenia pomiarowego, model matematyczny oraz sposób identyfikacji parametrów modelu. Metoda ta jest szczególnie przydatna w przypadku analizy właściwości materiałowej polimerów oraz tkanki chrząstki stawowej człowieka, zarówno...
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Nonlinear modeling of traction transformer with coiled iron core for dynamic simulation
PublicationW referacie przedstawiono wyprowadzenie zastępczego modelu obwodowego transformatora trakcyjnego o rdzeniu zwijanym do analiz zachowania sie transformatora w układzie napedowym jednostki trakcyjnej. Model zakłada nieliniowa charakterystyke magnesowania B-H i anizotropowe właściwosci magnetyczne i elektryczne zwijanego rdzenia. Wyprowadzenie modelu oparto na metodzie energetycznej Lagrange'a. Uzwojenia zostały zamodelowanie jako...
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Modeling the debonding process of osseointegrated implants due to coupled adhesion and friction
PublicationCementless implants have become widely used for total hip replacement surgery. The long-term stability of these implants is achieved by bone growing around and into the rough surface of the implant, a process called osseointegration. However, debonding of the bone–implant interface can still occur due to aseptic implant loosening and insufficient osseointegration, which may have dramatic consequences. The aim of this work is to...
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Theoretical study of thermofrictional oscillations due to negative friction-temperature characteristic
PublicationAnalytical study on oscillations of a body on a moving counterbody has been done by assuming imperfect frictional thermal contact and friction that decreases with contact temperature. It has been shown that stick-slip oscillation occurs due to decrease of friction coefficient when the body moves in the opposite direction to the counterbody. Dynamical characteristics, such as conditions for stable sliding and limit cycles, have...
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Analytical Study of Sliding Instability due to Velocity- and Temperature-Dependent Friction
PublicationThe instability of sliding causes deterioration of performance characteristics of tribosystems and is undesired. To predict its occurrence, the motion of a body of a one-degree-of-freedom system with friction is investigated about the steady sliding equilibrium position. The motion equation is formulated with the friction coefficient dependent on the sliding velocity and contact temperature changing due to transient heat conduction...
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Thermal boundary conditions to simulate friction layers and coatings at sliding contacts
PublicationA brief review of the thermal boundary conditions specified at sliding interfaces was performed. New thermal boundary conditions were derived aimed at solving problems of sliding with account of surface layers representing friction layers and tribological coatings. Based on the assumption of linear temperature distributions in the surface layers, the proposed conditions enable one to simplify simulations by eliminating the surface...
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COMPARISON OF THE ABRASION RESISTANCE OF THE SELECTED BIOMATERIALS FOR FRICTION COMPONENTS IN ORTHOPEDIC ENDOPROSTHESES
PublicationRosnące z każdym rokiem zapotrzebowanie na endoprotezy stawów ortopedycznych przy jednoczesnym dążeniu do zwiększenia ich trwałości i wyeliminowania negatywnych skutków ubocznych produktów zużycia, które mogą wywoływać proces zapalny w tkankach determinuje potrzebę poszukiwania nowych biomateriałów, bądź metody modyfikacji ich powierzchni. Nadrzędnym celem prowadzonych przez nas badań było oszacowanie intensywności zużycia ściernego...
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THE POSSIBILITY OF USE OF LASER-MODIFIED Ti6Al4V ALLOY IN FRICTION PAIRS IN ENDOPROSTHESES
PublicationThe purpose of this paper is to show results of laser treatment at cryogenic conditions of the Ti6Al4V alloy used for orthopedic applications. That modification process ought to bring beneficial changes of microstructure and residual stresses in the surface layer. The paper presents the abrasive wear of the base and laser remelted material in association with ceramics Al2O3. Despite the surface cracking after laser treatment the...
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Higher harmonics produced by traction substations – computer modelling and experimental verification
PublicationVoltage and current harmonics have a detrimental effect on the components of a power system. Current harmonics may result in the overload and damage to power transformers, although the rms value of load current does not exceed their current-carrying capacity. Voltage harmonics may result in, for example, damage to capacitor banks used to compensate reactive power. Devices which contribute to both current and voltage distortion...
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Contact with coupled adhesion and friction: Computational framework, applications, and new insights
PublicationContact involving soft materials often combines dry adhesion, sliding friction, and large deformations. At the local level, these three aspects are rarely captured simultaneously, but included in the theoretical models by Mergel et al., (2019). We here develop a corresponding finite element framework that captures 3D finite-strain contact of two deformable bodies. This framework is suitable to investigate sliding friction even...
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The concept of weighted mean friction angle in bearning capacity of footings of sands
PublicationZagadnienie średniej ważonej kąta tarcia wewnętrznego w nośności fundamentów posadowionych w gruntach niespoistych.
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Metabolic transformation of antitumor agent C1311 with various fractions of rat liver.
PublicationWykazano, że enzymatyczna aktywacja jest konieczna dla aktywności bilogicznej pochodnej C-1311. Zbadano przemiany związku w obecności różnych frakcji enzymatycznych mikrosomalnych komórek wątroby szczura.Badania te wykazały, że związek C-1311 jest bardziej podatny na transformację pod wpływem frakcji aktywowanych enzymów mikrosomalnych (CYP1A, CYP2B, CYP3A i CYP4A) niż frakcji S9, cytozolowej czy mikrosomów nieaktywowanych. Związek...
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Organic matter removal efficiency in treatment wetlands simulation by COD fractions
PublicationThe objective of this paper was to investigate the organic fraction (colloidal, particulate, and dissolved) in sewage treatment in treatment wetland. Performance of TWs was simulated well with a simple first order model k – C* based on monitoring data. In this investigation background or residual concentration (C*) was assumed to be equal concentration of input influent organic matter in particulate (CODp). Calculated reaction...
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Power converter interface for urban DC traction substations - solutions and functionality.
PublicationThis paper focuses on extending an urban DC traction substation functionality by means of an additional power converter interface (PCI). In particular, by enabling bidirectional energy exchange between LV DC traction grid, AC grid and V2G chargers. Among other things, the presented material compares general attributes of the most promising DC/DC converters that can be used in a PCI, meet the requirements of galvanic isolation and...
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An Overview of Bidirectional EV Chargers: Empowering Traction Grid-Powered Chargers
PublicationIn recent years, the number of electric vehicles has been at least doubling year after year. As a result, today electric vehicles already account for approximately 10% of the global automotive market, which positively affects environment in urbanized areas. However, to take full advantage of the EV integration it is necessary to use renewable sources for their charging; optimally place charging stations/terminals; optimally manage...
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Evaluation and cellular responses of modulators of TRF1/TRF2 protein’s function as potential anticancer drugs interfering with telomeric shelterin’s function
PublicationA number of proteins that interact with telomeres have been identified in human cells, indicating the high plasticity of human nucleoprotein complex organization. The most important complex is the "shelterin" complex, which consists of six proteins: TRF1, TRF2, TIN2, POT1, TPP1. The TRF1 and TRF2 directly bind to telomeric double-stranded DNA and the TIN2 protein. The TIN2 protein also binds to the TPP1 protein, stabilizing the...
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Bulletin of Chemical Reaction Engineering and Catalysis
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Postbiotics in oncology: science or science fiction?
PublicationThe gut microbiome has been increasingly understood to play a critical role in carcinogenesis and cancer disease progression. The most recent research advancements have shown that different tools of microbiota manipulation contribute to gut microbiome–immune–oncology axis modulation, offering exciting opportunities for targeted interventions aimed at improving the efficacy of established anti-cancer therapy. Postbiotics are a new...
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Green function diagonal for a class of heat equations
PublicationA construction of the heat kernel diagonal is considered as element of generalized zeta function theory, which gradient at the origin defines determinant of a differential operator in a technique for regularizing quadratic path integral. Some classes of explicit expressions of the Green function in the case of finite-gap potential coefficient of the heat equation are constructed. An algorithm and program for Mathematica are presented...
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THE FUNCTION OF GREENERY IN A SKYSCRAPER: THE PLACEMENT AND ITS INFLUENCE
PublicationThe contrast between the high rise buildings; with their mostly geometric shapes, and the organic form of the greenery was visible even in the idea of a skyscraper. Yet the realizations and recent projects show emerging interest and the link between them. To better understand the developing function of the greenery in the context of a skyscraper, both literature and case studies are conducted. The aim is to relate the location...
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Firing map of an almost periodic input function
PublicationIn mathematical biology and the theory of electric networks the firing map of an integrate-and-fire system is a notion of importance. In order to prove useful properties of this map authors of previous papers assumed that the stimulus function f of the system ẋ = f(t,x) is continuous and usually periodic in the time variable. In this work we show that the required properties of the firing map for the simplified model ẋ = f(t) still...