Filters
total: 2355
filtered: 1839
displaying 1000 best results Help
Search results for: TEHD CALCULATION
-
Bearing capacity of piles based on static load tests and calculation principles provided by EN 1997-1
PublicationW artykule scharakteryzowano i przeanalizowano ogólne zalecenia Eurokodu 7 dotyczące wyznaczania nośności pali na podstawie próbnych obciążeń statycznych. Porównano je z zaleceniami dotychczasowej polskiej normy PN-83/B-02482. Przedstawiono kilka przykładów interpretacji rzeczywistych wyników próbnych obciążeń pali według zaleceń wyżej wymienionych dwóch norm wraz z analizą porównawczą.
-
Calculation of Induced Sheath Voltages in Power Cables – Single Circuit System versus Double Circuit System
PublicationThis paper presents comparison of values of induced sheath voltages in power cable metallic sheaths when one or two cables per phase are used. Calculation of voltages is performed for various phase sequences of the power cables. Three types of the sheaths bonding and earthing are considered. Shock hazard and voltage stress of non-metallic outer sheath of cables are evaluated. The proposed, optimal configuration of the power cable...
-
Implementation of magnitude calculation of complex numbers using improved alpha max plus beta min algorithm
PublicationThe paper presents the hardware implementation of the improved alpha max plus beta min algorithm for calculating the magnitude of complex numbers. This version of the algorithm requires the general division which is performed using a noniterative multiplicative division algorithm. We analyze in detail the division algorithm, its error and the impact of finite word-length signal representations on the assumed total computation error....
-
The impact of surface slope and calculation resolution on the fractal dimension for fractures of steels after bending-torsion fatigue
PublicationThe article presents the results of the fractal dimension measurements on the fatigue fracture surfaces of 10HNAP and S355J2 steels specimens after combined bending-torsion fatigue. For smooth and ring-notched specimens, three loading conditions were analyzed: (1) bending; (2) bending-torsion; and (3) torsion fatigue. Post-failure surface topography measurements were carried out on the entire fracture surfaces using an optical...
-
Calculation of the standard potentials of the dithiocarbamate/thiuram disulfide redox system via thermochemical cycles and computational electrochemistry .
Publication.
-
Pumping effect measured by PIV method in multi-layer spike electrode EHD device for air cleaning
PublicationDust particles can be harmful for human health when inhaled. Especially dangerous are submicron dust particles, which can contain traces of toxic elements and can easily penetrate into human respiratory system. Thus, new devices for air cleaning are needed. In this work the flow velocity field patterns measured by Particle Image Velocimetry (PIV) method in an electrohydrodynamic (EHD) device for air cleaning are presented. The...
-
Computed vibrational excitation ofCF4by low-energy electrons and positrons: Comparing calculations and experiments
PublicationQuantum calculations for the excitation of the asymmetric modes of the CF4 target gas, ν3 and ν4, by impact of low-energy electrons and positrons are carried out in the energy range around 1 eV and are compared with recent experimental findings. The similarities and differences between the two types of projectiles, and the two different modes, are analyzed and discussed vis à vis the present accord with the experimental results.
-
Analytical calculations of scattering lengths for a class of long-range potentials of interest for atomic physics
PublicationWe derive two equivalent analytical expressions for an $l$th partial-wave scattering length $a_{l}$ for central potentials with long-range tails of the form % \begin{math} \displaystyle V(r)=-\frac{\hbar^{2}}{2m}\frac{Br^{n-4}}{(r^{n-2}+R^{n-2})^{2}} -\frac{\hbar^{2}}{2m}\frac{C}{r^{2}(r^{n-2}+R^{n-2})}, \end{math} % ($r\geqslant r_{s}$, $R>0$). % For $C=0$, this family of potentials reduces to the Lenz potentials discussed in...
-
Furan Fragmentation in the Gas Phase: New Insights from Statistical and Molecular Dynamics Calculations
PublicationWe present a complete exploration of the different fragmentation mechanisms of furan (C4H4O) operating at low and high energies. Three different theoretical approaches are combined to determine the structure of all possible reaction intermediates, many of them not described in previous studies, and a large number of pathways involving three types of fundamental elementary mechanisms: isomerization, fragmentation, and H/H2 loss...
-
Electron-impact ionization cross section calculations for 5-chloropyridine and 5-bromopyridine molecules
PublicationThe total cross sections for the single electron-impact ionization of 5-chloropyridine (5-C5H4ClN) and 5-bromopyridine (5-C5H4BrN) molecules have been calculated using binary-encounter-Bethe method for electron energies ranging from the ionization threshold up to 5 keV.
-
Structural studies of methyl brevifolincarboxylate in solid state by means of NMR spectroscopy and DFT calculations
Publication -
Crystal structure, hydrogen bonds, and lattice dynamics in kanemite from first-principles calculations
Publication -
Calculations of electron impact ionization cross section for simple biomolecules: formic and acetic acids
PublicationObliczono przekroje czynne na jednokrotną jonizację kwasu mrówkowego oraz kwasu octowego. Obliczenia przeprowadzono używając formalizmu BEB w zakresie energii od progu na jonizację do 400 eV. Wyniki porównano z dostępnymi danymi doświadczalnymi.
-
Critical review of propeller performance scaling methods based on model experiments and numerical calculations
PublicationThe article presents the results of experimental and theoretical investigation of propeller scale effects. The objective of this investigation is to test the adequacy of the methods currently used and to develop possible improvement of the methods.New approaches to the problem and new procedures to account for the propeller scale effects are suggested. The description of the underlying experimental and theoretical research is included.
-
Cost-Effective and Sufficiently Precise Integration Method Adapted to the FEM Calculations of Bone Tissue
PublicationThe technique of Young’s modulus variation in the finite element is not spread in biomechanics. Our future goal is to adapt this technique to bone tissue strength calculations. The aim of this paper is to present the necessary studies of the element’s integration method that takes into account changes in material properties. For research purposes, a virtual sample with the size and distribution of mechanical properties similar...
-
Non-adiabatic Effects in Pressure Drop Calculations in Flow Boiling and Flow Condensation in Minichannels
PublicationConsiderations presented in the paper relate both to the case of flow boiling and flow condensation in conventional channels as well as small diameter ones. Authors devoted all the possible attention that the modeling presented is applicable to the whole range of quality variation in both cases of condensation and boiling. The form of two-phase flow multiplier, which is a major factor in modeling presented here, should be capable...
-
Comparison of strain results at a laser weld notch obtained by numerical calculations and experimental measurements
PublicationIn the development of ship structures applying new materials and it’s purposeful placement play an important role. During the last years, especially in a construction of ro-ro type vessels, the usage of novel sandwich structures in cargo decks is profitable. Steel sandwich panel is an innovative solution which at a todays state of development can be used for the construction of any members not taking part in a global bending of...
-
Ab initio and density functional theory calculations of proton affinities for volatile organic compounds
PublicationThe Hatree-Fock method with 6-311G** split-valence molecular orbitals basis sets and the density function theory-B3LYP have been applied to geometrical optimizations and calculations of total electronic, zero point vibrational energies and proton affinities at 298 K for volatile organic compounds. Calculated values of proton affinities are compared with experimental data.
-
Cross sections calculations for electron scattering from dimethylamine, NH(CH3)2, molecule
PublicationThe total cross section for single electron-impact ionization and the integral elastic cross section for electron scattering from dimethylamine have been calculated using the binary-encounter-Bethe model and the independent atom method, respectively.
-
Research into flows in turbine blade seals. Part III: Numerical calculations versus experiment
PublicationPrzedstawiono wyniki badań doświadczalnych przepływów w uszczelnieniu nadbandażowym stopnia turbinowego, przeprowadzonych na powietrznej turbinie modelowej. Rezultaty te porównano z wynikami badań numerycznych z zastosowaniem programu Fluent.
-
Numerical calculations of wall pressures and stresses in steel cylindrical silos with concentric and eccentric hoppers
PublicationArtykuł przedstawia numeryczną analize naprężeń w płaszczu silosa. Porównane zostały wyniki dla silosów o przepływie centrycznym i mimośrodowym.
-
NIRCa: An artificial neural network-based insulin resistance calculator
Publication -
Mathematical model of the energy consumption calculation during the pine sawn wood (Pinus sylvestris L.) drying process
PublicationThe article presents the modification of the existing mathematical model to calculate energy consumption during conventional drying process. Apart from energy consumption the model permits to estimate the time of high-temperature drying process. The drying medium is air and superheated steam mixture. The obtained calculation results were compared with conducted experimental tests of drying square-edged sawn sapwood timber (Pinus...
-
Continuum wave functions for estimating the electric dipole moment: Calculation based on a multiconfiguration Dirac-Hartree-Fock approximation
PublicationThe multiconfiguration Dirac-Hartree-Fock method is employed to calculate the continuum electron wave functions, which are then used to estimate their contribution to the atomic electric dipole moment (EDM) of 129Xe. The EDM arises from (P,T)-odd electron-nucleon tensor-pseudotensor and pseudoscalar-scalar interactions, the nuclear Schiff moment, the interaction of the electron electric dipole moment with nuclear magnetic moments,...
-
Measurements and calculation of self inductance of testing coils used in physical transformer model construction and its frequency analysis
Publication -
A semi-empirical method for calculation of flow boiling heat transfer coefficients for conventional channels and small diameter tubes
PublicationW pracy przedstawiono rozważania na temat modelowania dwufazowego przepływu wrzącego w kanałach konwencjonalnych i w kanałach o małej średnicy. Przedstawiono modyfikację korelacji zaproponowanej wcześniej przez J. Mikielewicza na podstawie nowych danych eksperymentalnych, uzyskanych dla kanałów o małej średnicy. Bank danych obejmował ponad 460 punktów pomiarowych dla czynników R141b, R134a, R113, R123, R12, R11 i wody. Uzyskano...
-
A common method for calculation of flow boiling and flow condensation heat transfer coefficients in minichannels with account of nonadiabatic effects
PublicationW pracy przedstawiono metodę ogólną wyznaczania współczynników przejmowania ciepła podczas wrzenia w przepływie i kondensacji w przepływie w minikanałach z uwzględnieniem efektu nieadiabatycznego. Uwzględnia ona wpływ modyfikacji naprężeń stycznych na granicy ciecz-para na wymianę ciepła.
-
Non-isothermal effects in a common method for calculation of heat transfer coefficient in flow boiling and flow condensation in minichannels
PublicationW pracy przestawiono efekty nieizotermiczne w metodzie wyznaczania współczynnika przejmowania ciepła podczas wrzenia w przepływie oraz kondensacji w przepływie w minikanałach. Wyniki obliczeń porównano z badaniami eksperymentalnymi z literatury, uzyskując dobrą zgodność.
-
Service time distribution influence on end-to-end call setup delay calculation in networks with Session Initiation Protocol
PublicationThe most important GoS parameter for networks with SIP protocol is end-to-end call setup delay. So far there were no coherent models allowing calculation of these parameters for networks with SIP protocol. Few models were developed but they are insufficient. In the paper we propose model which allows end-to-end call setup delay calculation for networks with SIP protocol. The model is using chain of M/G/1/K models and is applicable...
-
Calculating the Partition Coefficients of Organic Solvents in Octanol/Water and Octanol/Air
PublicationPartition coefficients define how a solute is distributed between two immiscible phases at equilibrium. The experimental estimation of partition coefficients in a complex system can be an expensive, difficult, and time-consuming process. Here a computational strategy to predict the distributions of a set of solutes in two relevant phase equilibria is presented. The octanol/water and octanol/air partition coefficients are predicted...
-
Liquid circulation in the agitated airlift reactor with the high gas disengagement zone
PublicationPrzedstawiono doświadczalne zależności stopnia zatrzymania gazu i prędkości cyrkulacji cieczy od prędkości przepływu gazu i częstości obrotów mieszadła. Obserwowano wzrost prędkości cyrkulacji cieczy ze wzrostem wysokości strefy napowietrzania. Dla niskich częstości obrotów mieszadła prędkość cyrkulacji cieczy wzrastała wraz ze wzrostem prędkości przepływu gazu, natomiast dla wysokich cząstości obrotów mieszadła prędkość cyrkulacji...
-
The Effect of Calcination Temperature on Structure and Photocatalytic Properties of WO3/TiO2 Nanocomposites
PublicationSeries ofWO3/TiO2 nanocompositeswere obtained by hydrothermal method followed by calcination in the temperature range from 400∘C to 900∘C. The characteristics of photocatalysts by X-ray diffractometry (XRD), scanning electron microscope (SEM), and diffuse reflectance spectroscopy (DRS) showed that increasing the calcination temperature from 400 to 900∘C resulted in change of photocatalytic activity under UV-Vis light.Moreover,...
-
Multi-state multi-reference Møller-Plesset second-order perturbation theory for molecular calculations
PublicationThis work presents multi‐state multi‐reference Møller–Plesset second‐order perturbation theory as a variant of multi‐reference perturbation theory to treat electron correlation in molecules. An effective Hamiltonian is constructed from the first‐order wave operator to treat several strongly interacting electronic states simultaneously. The wave operator is obtained by solving the generalized Bloch equation within the first‐order...
-
DL_MG: A Parallel Multigrid Poisson and Poisson–Boltzmann Solver for Electronic Structure Calculations in Vacuum and Solution
PublicationThe solution of the Poisson equation is a crucial step in electronic structure calculations, yielding the electrostatic potential -- a key component of the quantum mechanical Hamiltonian. In recent decades, theoretical advances and increases in computer performance have made it possible to simulate the electronic structure of extended systems in complex environments. This requires the solution of more complicated variants of the...
-
Moisture Influence on Compressive Strength of Calcium Silicate Masonry Units–Experimental Assessment and Normative Calculations
Publication -
Evaluation of water turbine hydrodynamic thrust bearing performance on the basis of thermoelastohydrodynamic calculations and operational data
Publication -
Band structure, Born effective charges, and lattice dynamics of CuInS2 from ab initio calculations
Publication -
Comparing N3-60 cascade exit angles obtained from tunnel measurements and numerical calculations
PublicationThe article compares the results of measurements performed in the aerodynamic tunnel at CUT and numerical simulation carried out for a plane cascade of N3-60 profiles. Comparing the measured and calculated results provides opportunities for assessing the range of systematic differences between simulation predictions and actual experimental results.
-
JMATRIX - a package for relativistic J-matrix calculations in elastic scattering of electrons from model potentials
PublicationWe present a software package JMATRIX, consisting of two computer codes written in FORTRAN 95 and parallelized with OpenMP, implementing the so-called J-matrix method, applied to elastic scattering of electrons on the radial potential, vanishing faster than Coulomb one. In the J-matrix method, physical scattering problem is replaced by using well-defined model, which is solved analytically. Presented software implements both non-relativistic...
-
Characterization of Bioactivity of Selective Molecules in Fruit Wines by FTIR and NMR Spectroscopies, Fluorescence and Docking Calculations
PublicationFourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopies were applied to characterize and compare the chemical shifts in the polyphenols’ regions of some fruit wines. The obtained results showed that FTIR spectra (1800–900 cm−1) and 1H NMR (δ 6.5–9.3 ppm) of different fruit wines can be used as main indices of the year of vintage and quality of fruit wines. In addition to the classical determination...
-
A Novel Ru(II) Polypyridine Black Dye Investigated by Resonance Raman Spectroscopy and TDDFT Calculations
PublicationThe optical properties of a new(bipyridine)2Ru(4H-imidazole) complex presenting a remarkablebroad absorption in the visible range are investigated. Thestrong overlap of the absorption with the solar radiationspectrum renders the studied complex promising as a blackabsorber and hence as a starting structure for applications inthe field of dye-sensitized solar cells. The correlations betweenstructural and electronic features for...
-
Properties of Oxygen Vacancy and Hydrogen Interstitial Defects in Strontium Titanate: DFT + Ud,p Calculations
PublicationThis work presents extensive theoretical studies focused on the mixed ion-electron transport in cubic strontium titanate (STO). A new approach to the description of this difficult system was developed within the framework of linear-scaling Kohn–Sham density functional theory, as realized in the ONETEP program. The description we present is free of any empirical parameters and relies on the Hubbard U and Hund’s J corrections applied...
-
Evaluation of water turbine hydrodynamic thrust bearing performance on the basis of thermoelastohydrodynamic calculations and operational data.
PublicationW pracy przedstawiono analizę konstrukcji łożyska wzdłużnego turbiny wodnej. Łożysko zostało skonstruowane około 50 lat temu, a jego konstrukcja przewiduje kompensację termicznych odkształceń klocków. W analizie uwzględniono odkształcenia łożyska i wymianę ciepła w filmie smarowym i klockach łożyskowych. Poza obecną konstrukcją łożyska przeprowadzono również studium wpływu podstawowych parametrów konstrukcyjnych: grubości klocka...
-
Comparative DEM calculations of fracture process in concrete considering real angular and artificial spherical aggregates
PublicationArtykuł omawia wyniki obliczeń numerycznych pękania dla betonu stosując metodę elementów dyskretnych (DEM). Beton był opisany jako materiał 4-fazowy i był poddany zginaniu. Zbadano wpływ kształtu kruszywa na proces pekania i na zalezność obciązenia od ugięcia. Wyniki dwuwymiarowe i trzywymiarowe porównano bezpośrednio z doświadczeniami. Wyniki pokazały duzy wpływ kształtu kruszywa na wyniki numeryczne.
-
Buckling resistance of a metal column in a corrugated sheet silo - experiments and non-linear stability calculations
PublicationThe results of experimental and numerical tests of a single corrugated sheet silo column’s buckling resistance are presented in this study. The experiments were performed in a real silo with and without bulk solid (wheat). A very positive impact of the bulk solid on the column buckling resistance occurred. The experimental results were first compared to the buckling resistance calculated by Eurocode 3 formulae. The comparison revealed that...
-
Calculation of the Effects of Implementing a DSM Electricity Demand Management Strategy Using the Example of Analysis of Changes in the Power System Load
PublicationThe paper presents the impact of implementing Demand Side Management (DSM) solutions through proper management and control of the process of charging and discharging electric car batteries. As a result, the daily load curves were shaped so as to fill valleys and cut down peaks. Therefore, the implementation of power demand management solutions had a significant impact on the power system operation. The impact of DSM solutions manifested...
-
The Effect of Surface Topography Feature Size Density and Distribution on the Results of a Data Processing and Parameters Calculation with a Comparison of Regular Methods
Publication -
A new duty cycles calculation method in pulse width modulation for direct matrix converters based on the shape function concept
PublicationPaper presents a new approach to duty cycle calculation in pulse width modulation for direct matrix converters. The essence of the proposed method is the use of elementary shape function of finite element. The algorithm for calculating the duty cycles was reduced to simple operations on the coordinates of input and output voltage vectors without trigonometric functions.
-
Novel binary mixtures of alkanolamine based deep eutectic solvents with water - thermodynamic calculation and correlation of crucial physicochemical properties
PublicationThis paper demonstrates the assessment of physicochemical and thermodynamic properties of aqueous solutions of novel deep eutectic solvent (DES) built of tetrabutylammonium chloride and 3-amino-1-propanol or tetrabutylammonium bromide and 3-amino-1-propanol or 2-(methylamino)ethanol or 2-(butylamino)ethanol. Densities, speeds of sound, refractive indices, and viscosities for both pure and aqueous mixtures of DES were investigated...
-
Calculation of silicon cell temperature of loaded photovoltaic module based on thermal coefficients for different weather conditions of Northern Poland
PublicationWydajność obciążonego modułu fotowoltaicznego zależy silnie od natężenia promieniowania słonecznego, temperatury otoczenia, prędkości wiatru i temperatury wewnętrznej składowych ogniw fotowoltaicznych. Sprawność konwersji fotowoltaicznej spada istotnie wraz z e wzrostem temperatury złącza p-n. Pomiar tej temperatury jest niemożliwy i oblicza się ją w oparciu o mierzoną wartość temperatury przedniej lub tylnej powierzchni modułu...