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Search results for: KINETIC CONSTANTS
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Analysis of TL and OSL kinetics of lithium aluminate
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Kinetics of nitrogen removal processes in constructed wetlands
PublicationThe aim of this paper is to present a state-of-the-art review of the kinetics of nitrogen removal in constructed wetlands. Biological processes of nitrogen removal from wastewater can be described using equations and kinetic models. Hence, these kinetic models which have been developed and evaluated allow for predicting the removal of nitrogen in treatment wetlands. One of the most important, first order removal model, which is...
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Predicting Value of Binding Constants of Organic Ligands to Beta-Cyclodextrin: Application of MARSplines and Descriptors Encoded in SMILES String
PublicationThe quantitative structure–activity relationship (QSPR) model was formulated to quantify values of the binding constant (lnK) of a series of ligands to beta–cyclodextrin (β-CD). For this purpose, the multivariate adaptive regression splines (MARSplines) methodology was adopted with molecular descriptors derived from the simplified molecular input line entry specification (SMILES) strings. This approach allows discovery of regression...
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Characteristic of Morpholinium Ionic Liquids as Gas Chromatography Stationary Phases with McReynolds Constants and Activity Coefficients at Infinite Dilution
PublicationIn this work, four ionic liquids based on N-alkyl-N-methylmorpholinium cation ([Mor1,R] where R= 2, 4, 8, 10) and bis(trifluoromethanesulfonyl)imide anion [TFSI] were synthesized. Using gas-liquid chromatography a number of parameters describing the sorption properties of the investigated ionic liquids were determined. The values of Kovats indices, McReynolds constants, and activity coefficients at infinite dilution were the basis...
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Nuclear magnetic shielding constants of Dirac one-electron atoms in some low-lying discrete energy eigenstates
PublicationWe present tabulated data for the nuclear magnetic shielding constants (σ) of the Dirac one-electron atoms with a pointlike, motionless and spinless nucleus of charge Ze. Utilizing the exact general analytical formula for σ derived by us (Stefańska, 2016) valid for an arbitrary discrete energy eigenstate, we have computed the numerical values of the magnetic shielding factors for the ground state and for the first and the second...
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Micromechanical analysis of friction anisotropy in rough elastic contacts
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Effect of wear on EHD film thickness in sliding contacts
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Comparative analysis of various transformation techniques for voiceless consonants modeling
PublicationIn this paper, a comparison of various transformation techniques, namely Discrete Fourier Transform (DFT), Discrete Cosine Transform (DCT) and Discrete Walsh Hadamard Transform (DWHT) are performed in the context of their application to voiceless consonant modeling. Speech features based on these transformation techniques are extracted. These features are mean and derivative values of cepstrum coefficients, derived from each transformation....
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Size reduction of ultra-wideband antennas with efficiency and matching constraints
PublicationAntenna design is a multifaceted task that involves handling of various performance figures concerning both electrical performance of the structure as well as its geometry. Simultaneous control of several objectives through rigorous optimization is very challenging and virtually impossible through conventional approaches such as parameter sweeping. In this work, we investigate size reduction of ultra‐wideband antenna structures...
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Wood structure constraints on sawing accuracy with narrow-kerf saws
PublicationW pracy przedstawiono analizę przyczyn i przykłady niedokładności przecinania wynikających z lokalnych zmian struktury drewna.
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Determining diagnostic coverage of elements and analysis of subsystems` architectural constraints
PublicationWypełnienie funkcji bezpieczeństwa przez systemy E/E/PE łączy się z niezawodnym działaniem podsystemów, których struktura i właściwości muszą gwarantować skuteczne i szybkie wykrywanie uszkodzeń. Do określenia przeciętnego prawdopodobieństwa niewypełnienia funkcji bezpieczeństwa na żądanie (PFDavg) niezbędna jest znajomość pokrycia diagnostycznego w odniesieniu do wszystkich podsystemów. Najlepiej, aby podsystemy były zaliczane...
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Urban Freight Transport Demand Modelling and Data Availability Constraints
PublicationThe paper provides a review of urban freight transport demand modelling approaches confronted with constrains regarding adequate data provision from a perspective of the local authorities. Demand estimation models has been selected as a reference because they are the most representative in terms of inclusion of urban freight indicators which can be transformed into a decision-support tool for evaluation of freight measures. The...
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Photodegradation of single and mixture of parabens – Kinetic, by-products identification and cost-efficiency analysis
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Kinetic and equilibrium studies of the reaction of 2,4-dinitrophenyl-2,4,6-trinitrophenylmethane with cryptands in acetonitrile
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Effective sonophotocatalytic degradation of tetracycline in water: Optimization, kinetic modeling, and degradation pathways
PublicationHybrid advanced oxidation processes (AOPs) are gaining interest in degradation of variety of recalcitrant compounds for water and wastewater treatment, due to possible synergistic effects. The present study systematically evaluated the degradation of tetracycline (TC) with a sonophotocatalytic process combining acoustic cavitation (sonocavitation) and photocatalysis based on N-doped TiO2 catalyst. The TC degradation rate constant...
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Modelling of the Baumann turbine stage operation Part II. Free and kinetic vibrations
PublicationIn this paper has been presented a methodology of validation a novel mathematical model dedicated to evaluation and prediction of material degradation and demage of steam turbine elements such as blades, valves and pipes due to three mechanisms: stress-corosion, high-temperature creep and low-cyclic fatigue. The validation concept is based on an experimental setup manufactured in the Laboratory of Faculty of Mechanical and Power...
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High-cycle fatique criterion for anisotropic metals under multiaxial constant and periodic loads
PublicationPrzedmiotem rozważań jest okresowe naprężenie, którego kartezjańskie składowe są dane w postaci szeregów Fouriera. Dla uwzględnienia wpływu składowych stałych zastosowano zmodyfikowaną formułę Soderberga. Zdefiniowano naprężenie równoważne o synchronicznych składowych i sformułowano kryterium ograniczonej trwałości zmęczeniowej. Kryterium to obejmuje warunki wytrzymałości statycznej i bezpieczeństwa zmęczeniowego z zakresie wysokocyklowym...
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Fatigue ''safe-life'' criterion for metal elements under multiaxial constant and periodic loads.
PublicationRozpatrywane jest okresowe naprężenie którego kartezjańskie składowe są zadane w postaci szeregów Fouriera. Dla uwzględnienia naprężenia średniego wykorzystano uogólnioną formułę Soderberga dla materiałów ciągliwych. Zdefiniowano naprężenie równoważne o synchronicznych składowych i sformułowano kryterium zmęczenia, które obejmuje warunki zarówno wytrzymałości statycznej jak i bezpieczeństwa zmęczeniowego. Kryterium to zawiera stałe...
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Dimensional Synthesis of Coupled-Resonator Pseudoelliptic Microwave Bandpass Filters with Constant and Dispersive Couplings
PublicationIn this paper, we propose a novel technique for the dimensional synthesis of coupled-resonator pseudoelliptic microwave filters with constant and dispersive couplings. The proposed technique is based on numerical simulations of small structures, involving up to two adjacent resonators, and it accounts for a loading effect from other resonators by replacing them with terminations coupled through appropriately scaled inverters. The...
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Kineta monolityczna
PublicationTechnologia betonu samozagęszczającego się. Produkcja monolitycznej betonowej kinety. Zasadnicze wiadomości o wyrobie, jego zastosowania. Aktualny stan produkcji
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Tailoring optical constants of few-layer black phosphorus coatings: Spectroscopic ellipsometry approach supported by ab-initio simulation
Publication2D black phosphorus (BP) has attracted extensive attention as an anisotropic platform for novel optoelectronic and polarizing optics applications. Insight into the factors that tune the optical and polarizing properties of 2D BP reveals their essential influence on BP-based photonic and optoelectronic devices. In this work, studies of the optical constants of few-layer black phosphorus coatings are studied and discussed, with particular...
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Evaluation of Gas Chromatography Stationary Phases Based on Morpholinium Ionic Liquids by McReynolds Constants and Activity Coefficients at Infinite Dilution
PublicationIn this work, four ionic liquids (ILs) based on the N-alkyl-N-methylmorpholinium cation ([Mor1,R], in which R = 2, 4, 8, or 10) and bis (trifluoromethanesulfonyl)imide anion were synthesized. Using GLC, a number of parameters describing the sorption properties of the investigated ILs were determined. The values of Kovats indices, McReynolds constants, and activity coefficients at infinite dilution were the basis for the evaluation...
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Generalized temperature dependence model for anammox process kinetics
PublicationTemperature is a key operational factor influencing the anammox process kinetics. In particular, at temperatures below 15 °C, the specific anammox activity (SAA) considerably decreases. This study aimed to describe the temperature dependence of the anammox process kinetics in the temperature range from 10 to 55 °C, including the specific characteristics of“cold anammox”. The commonly used Arrhenius and extended and modifiedRatkowsky...
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Degradation kinetics and mechanism of pentoxifylline by ultraviolet activated peroxydisulfate
PublicationDegradation of pentoxifylline (PTX) by sodium peroxydisulfate (SPDS) assisted by UV irradiation has been investigated in deionized water. The treatment was more favorable over direct photolysis or peroxydisulfate oxidation alone. The effects of various parameters, including different dosage of oxidant agent, PTX concentration, initial solution pH levels, and the presence of inorganic ions like chloride, nitrate and carbonate have...
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Luminescence and Luminescence Kinetics of Gd3Ga5O12Polycrystals Doped with Cr3+and Pr3+
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Nonisothermal cure kinetics of epoxy/MnxFe3-xO4 nanocomposites
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Phototransformation of Amlodipine: Degradation Kinetics and Identification of Its Photoproducts
PublicationNowadays, monitoring focuses on the primary compounds and does not include degradation products formed during various biological and chemical processes. Transformation products may have the same effects to human health and the environment or sometimes they can be more toxic than the parent compound. Unfortunately, knowledge about the formation of degradation products is still limited, however, can be very important for the environmental...
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Kinetics and mechanism of the chemically modified starches during gelatinization.
PublicationNative starch was silicated by means of microwave-assisted reactions with varying doses of reagents. Resulting products were characterized by DSC and HMR-relaxation methods. It was observed that the hydratation of the silicated starches during gelatinization decreases when compared to that of the native potato starch. The amount of unfrozen water for ungelitinizated silicated starches are less than in control samples. At the same...
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Kinetics of the crosslinking reaction between genipin and chitosan solutions
PublicationThe kinetics of the chitosan crosslinking reaction with genipin was examined. The strong relationship was found between crosslinking agent concentration, chitosan concentration, temperature and gelling time. Data obtained will be used in the proper selection of optimal genipin concentration for crosslinking chitosan solutions.
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EXPERIMENTAL EVALUATION OF DLC/STEEL SLIDING CONTACTS’ OPERATIONAL ENVELOPE
PublicationIn an industrial project concerning sliding bearings, a sliding pair was selected of high alloy steel vs. industrial grade DLC coated high alloy steel as a basis for an innovative design of high performance sliding bearings lubricated with a synthetic oil for use in geared transmission units. The development process required credible data on the ultimate resistance of the sliding pair to very high contact stress. An experimental...
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Influence of magnetic field on wear in high frequency reciprocatingsliding contacts
PublicationResults of experimental studies concerning the influence of permanent magnetic field on wear of dry sliding contact operating at short stroke and high frequency are presented. It was found that horizontal magnetic field with different orientations relative to the sliding direction is affecting performance of the contact. The increase in frequency of sliding reduces accumulated mass loss and lowers the surface roughness of the wear...
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Performance of acicular grindable thermocouples for temperature measurements at sliding contacts
PublicationThe present study investigates the performance of acicular grindable thermocouples based on a constantan wire / steel hollow cylinder construction. The experiments showed that the measuring junction electrical resistance, temperature–voltage characteristic, measuring junction rise time and signal noise standard deviation of the acicular thermocouples are comparable to those of conventional J-type thermocouples with bare wire diameter...
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Scheduling with precedence constraints: mixed graph coloring in series-parallel graphs.
PublicationW pracy rozważono problem kolorowania grafów mieszanych, opisujący zagadnienie szeregowania zadań, w którym zależności czasowe zadań mają charakter częściowego porządku lub wzajemnego wykluczania. Dla przypadku, w którym graf zależności jest szeregowo-równoległy, podano algorytm rozwiązujący problem optymalnie w czasie $O(n^3.376 * log n)$.
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Current mechanisms of IGP routing - expectations and possibilities in terms of QoS constraints
PublicationOd mechanizmów rutingu oczekuje się nowych możliwości z chwilą wprowadzenia wymagań QoS. W tym kontekście aktualne techniki rutingu IGP nie oferuja rozwiązań określających ścieżki gwarantujące QoS. W pracy przedstawiono propozycję rozszerzenia OSPF, które umożliwia uwzględnienie ograniczeń wynikających z QoS, gwarantując jednocześnie usługi na żądanym poziomie. To rozszerzenie zawiera zarówno liniowe jak i nieliniowe metryki. Wartości...
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Kinetic characterization of hydrogen sulfide inhibition of suspended anammox biomass from a membrane bioreactor
PublicationThe inhibition effects of hydrogen sulfide (H2S) on anammox-enriched biomass from a laboratory membrane reactor were analyzed in a series of batch respirometric experiments. The determined half maximal inhibitory concentration (IC50) was 4.67 mg H2S-S L−1 at the constant pH = 7.0 and the total sulfide concentration varying between 1 and 15 mg TS-S L−1. In another test, the IC50 was found to be 4.25 mg H2S-S L−1 under a constant...
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Kinetic flux vector splitting scheme for solving non-reactive multi-component flows
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Numerical Investigation of Nuclear Reactor Kinetic and Heat Transfer Fractional Model with Temperature Feedback
PublicationAbstract—In the paper, the numerical results concerning the kinetics and proposed heat exchange models in nuclear reactor based on fractional calculus are presented for typical inputs. Two fractional models are proposed and compared with the model based on ordinary derivative. The first fractional model is based on one of the generalized Cattaneo equations. The second one is based on replacing the ordinary to fractional order of...
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Bifurcation of equilibrium forms of a gas column rotating with constant speed around its axis of symmetry
PublicationWe will be concerned with the problem of deformation of the lateral surface of a column that rotates with constant speed around its axis of symmetry. The column is filled by a gas and our goal is to investigate the deformation of the lateral surface depending on the pressure of the gas.
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Resistance changes of carbon nanotubes decorated with platinum nanoparticles in the presence of hydrogen at different and constant concentrations
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The dying medium temperature impact on the final moisture content of pine wood at constant drying time
PublicationThe results of final moisture content of pine wood (Pinus sylvestris L.) after drying process are presented. The wood in the experiments was taken from the northern part of Pomeranian region in Poland. The drying process was performed in the experimental chamber equipped with the micro-jet heat exchanger. The air at temperatures of 40°C, 60°C, 80°C, 100°C and 120°C with relative humidity about 60% and atmospheric pressure was the...
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Estimation of concentration equilibrium constants of reaction between mutagenic HAA and antimutagenic cabbage phytochemicals based on data from Ames test
PublicationWykorzystano dane testu Amesa, przy pomocy którego oceniono antymutagenne właściwości fitokompleksu kapusty w stosunku do modelowych kancerogennych heterocyklicznych amin aromatycznych (HAA), do oszacowania stężeniowych stałych reakcji HAA z izotiocyjanianami występującymi w tym warzywie. Wyznaczone stężeniowe stałe reakcji wskazują na dużą stabilność powstałych koniugatów, a zatem sugerują, że kapusta może efektywnie chronić organizm...
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The Influence of Alkyl Chain Length and Steric Effect on the Stability Constants and Extractability of Co(II) Complexes with 1-Alkyl-2-Methylimidazoles
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Kinetics of cross-linking processes of fast-curing polyurethane system
PublicationThis work focuses on the application of thermal analysis and kinetics investigations to analyze chemical processes during cross-linking of the complex fast-curing polyurethane system. Non-isothermal Differential Scanning Calorimetry (DSC) measurements were performed for both stoichiometric mixtures of polyol and isocyanate component and for mixture with large isocyanate excess. Isoconversional methods were used to calculate initial...
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Study of the Kinetics of Ammonia Synthesis and Decomposition on Iron and Cobalt Catalysts
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Kinetics studies of recrystallization process of metallic catalysts for ammonia synthesis
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Kinetics and mechanism of the dehydrohalogenation of Ar2CHCX3 and Ar2CHCHX2 by strong N-bases
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Kinetics of photochromic reactions in a 10-membered dibenzoazo crown ether
PublicationPrzedstawiono rezultaty pomiarów kinetyki fotochromowych reakcji dla jednego z serii eterów koronowych zawierających fragment azobenzenowy. Badano 10-członową dibenzoazokoronę, która ulega odwracalnej foto i termicznej izomeryzacji, podobnie jak macierzysty azobenzen. Eksperymenty były prowadzone w matrycy pMMA. Reakcja izomeryzacji monitorowana była spektrofotometrycznie. Czynnik przedwykładniczy dla termicznej izomeryzacji cis-trans...
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Photoluminescence Kinetics of YAG Crystals Activated with Ce, and Ce and Mg
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Analysis of TL and OSL kinetics in lithium magnesium phosphate crystals
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Numerical solution of fractional neutron point kinetics in nuclear reactor
PublicationThis paper presents results concerning solutions of the fractional neutron point kinetics model for a nuclear reactor. Proposed model consists of a bilinear system of fractional and ordinary differential equations. Three methods to solve the model are presented and compared. The first one entails application of discrete Grünwald-Letnikov definition of the fractional derivative in the model. Second involves building an analog scheme...