Filtry
wszystkich: 6951
wybranych: 5660
-
Katalog
- Publikacje 5660 wyników po odfiltrowaniu
- Czasopisma 100 wyników po odfiltrowaniu
- Osoby 152 wyników po odfiltrowaniu
- Wynalazki 8 wyników po odfiltrowaniu
- Projekty 16 wyników po odfiltrowaniu
- Zespoły Badawcze 2 wyników po odfiltrowaniu
- Kursy Online 109 wyników po odfiltrowaniu
- Wydarzenia 35 wyników po odfiltrowaniu
- Dane Badawcze 869 wyników po odfiltrowaniu
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: UNSTEADY FORCES
-
Modeling of Passive and Forced Convection Heat Transfer in Channels with Rib Turbulators
PublikacjaThe main goal of the research presented in this paper was the experimental and numerical analysis of heat enhancement and aerodynamic phenomena during air flow in a channel equipped with flow turbulators in the form of properly configured ribs. The use of ribs intensifies the heat transfer and at the same time increases not only the flow resistance but also the energy costs. Therefore, designing modern heat exchangers with optimal...
-
Numerical Modelling of Forced Convection of Nanofluids in Smooth, Round Tubes: A Review
PublikacjaA comprehensive review of published works dealing with numerical modelling of forced convection heat transfer and hydrodynamics of nanofluids is presented. Due to the extensive literature, the review is limited to straight, smooth, circular tubes, as this is the basic geometry in shell-and-tube exchangers. Works on numerical modelling of forced convection in tubes are presented chronologically in the first part of the article....
-
Cutting forces and temperature measurements in cryogenic assisted turning of AA2024-T351 alloy: An experimentally validated simulation approach
Publikacja -
Evaluation of adhesive forces and the specific surface energy of zirconia stabilized by yttria with alumina additions ceramic by AFM method
PublikacjaThe adhesive forces and the specific surface energy of ceramic material surfaces are very important for further tribological and biomedical applications of ceramics. Partially stabilized zirconia (zirconium oxide) is popular for manufacturing various medical products. ZrO2 stabilized by Y2O3 with additions of 5 wt% alumina was produced by slip casting method with a subsequent sintering. Structure and chemical composition of ceramic...
-
Numerical Analysis of Steady Gradually Varied Flow in Open Channel Networks with Hydraulic Structures
PublikacjaIn this paper, a method for numerical analysis of steady gradually varied fl ow in channel networks with hydraulic structures is considered. For this purpose, a boundary problem for the system of ordinary differential equations consisting of energy equation and mass conservation equations is formulated. The boundary problem is solved using fi nite difference technique which leads to the system of non-linear algebraic equations....
-
Sopot Forest Opera - history and future
PublikacjaW artykule przedstawiono historię Opery Leśnej w Sopocie oraz plany budowy jej nowego przekrycia.
-
The laboratory kit of EMC disturbances sources
PublikacjaPrzedstawiono podstawowe przyczyny powstawania zakłóceń w urządzeniach elektrycznych i elektronicznych oraz metody i sposoby ich analizy. Przedstawiono również koncepcje układów elektronicznych mających być wzorcowymi źródłami zaburzeń stosowanymi podczas ćwiczeń laboratoryjnych. Jako źródła zaburzeń małych i wysokich częstotliwości wybrano układy mogące być łatwo sterowane i zmieniane w celu wskazania konieczności stosowania rozwiązań...
-
Sources of Return in the Index Futures Markets
Publikacja -
Storing energy from renewable sources
PublikacjaOmówiono metody, urządzenia i sposoby magazynowania energii mechanicznej, elektrycznej, cieplnej i chemicznej z uwzględnieniem energii ze źródeł odnawialnych.
-
Platforma KASKADA - proces wytwarzania oprogramowania
PublikacjaZostał przedstawiony proces wytworzenia Platformy KASKADA służącej do przetwarzania strumieni multimedialnych w rozproszonym środowisku superkom-putera. Przedstawiono wymagania dotyczące Platformy, a następnie opisano przyjętą metodykę wytwarzania. Opi-sano przebieg poszczególnych iteracji procesu. Przedsta-wiono proces wytwarzania usług, od implementacji algo-rytmu, przez wdrożenie na Platformę, aż po akceptację i udostępnienie...
-
Adjustment for shape restoration and force control of cable arch stayed bridges
Publikacja -
An Approximate Linear Analysis of Structures Utilizing Incremental Loading of Force Method
Publikacja -
The theoretical description of friction force in bio-joints as function of cartilage roughness
PublikacjaWartości sił tarcia w naturalnych stawach człowieka a szczególnie w endoprotezach stawu biodrowego rzutują na proces zużywania się powierzchni stawowych. Dlatego problem wyznaczania sił tarcia w biołożyskach jest bardzo istotny. W trakcie chodzenia mamy co najmniej ruch sferycznej powierzchni głowy w dwóch różnych kierunkach dla naturalnych i sztucznych stawów biodrowych człowieka. Dlatego też siły tarcia występują co najmniej...
-
On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages
PublikacjaThis paper presents experimental investigations which made it possible to determine dynamic coefficients of labyrinth over-shroud seal of a model air turbine. The coefficients associate pressure forces with turbine rotor displacement, velocity and acceleration respective to turbine casing (linear model) and play important role in analyzing turbine-set dynamics. The obtained results indicated that involving serious errors can be...
-
Efficient sampling of high-energy states by machine learning force fields
Publikacja -
Simulation of Protein Structure and Dynamics with the Coarse-Grained UNRES Force Field
Publikacja -
Impact force spectrum for damage assessment of earthquake-induced structural pounding
PublikacjaCelem artykułu jest zastosowanie spektrum siły zderzenia do szacowania zniszczeń powstałych na skutek zderzeń pomiędzy konstrukcjami budowlanymi, do których dochodzi podczas trzęsień ziemi. Wyniki analizy wskazują, iż spektrum takie może być przydatnym narzędziem przy projektowaniu konstrukcji podatnych na zderzenia. Przykłady spektrów odpowiedzi pokazują, iż zapewnienie odpowiedniej przerwy dylatacyjnej lub zgranie parametrów...
-
Perceptual and Motor Effects of Muscle Co-activation in a Force Production Task
PublikacjaWe tested several predictions of the theory of motor control with spatial referent coordinates related to effects of muscle coactivation on force production and perception. In particular, we predicted that subjects would produce unintentional force increase by finger flexors and be unaware of this force increase. Healthy subjects performed steady force production task in isometric conditions with visual feedback on the force level....
-
Mechanical Properties of Single-Walled Carbon Nanotubes with AIREBO Force-Filed
Publikacja -
Dynamic Nanoimpedance Characterization of the Atomic Force Microscope Tip-Surface Contact
PublikacjaNanoimpedance measurements, using the dynamic impedance spectroscopy technique, were carried out during loading and unloading force of a probe on three kinds of materials of different resistivity. These materials were: gold, boron-doped diamond, and AISI 304 stainless steel. Changes of impedance spectra versus applied force were registered and differences in the tip-to-sample contact character on each material were revealed. To...
-
Enhancing capabilities of Atomic Force Microscopy by tip motion harmonics analysis
PublikacjaMotion of a tip used in an atomic force microscope can be described by the Lennard-Jones potential, approximated by the van der Waals force in a long-range interaction. Here we present a general framework of approximation of the tip motion by adding three terms of Taylor series what results in non-zero harmonics in an output signal. We have worked out a measurement system which allows recording of an excitation tip signal and its...
-
Piezoresponse force microscopy and dielectric spectroscopy study of Ba0.6Sr0.4TiO3 thin films
PublikacjaResearch on synthesis, characterization and determination of processing – structure – property relationships of commercially important ferroelectric thin films has been performed. The sol-gel-type solution deposition technique was applied to produce good quality thin films of Ba0.6Sr0.4TiO3 (BST60/40) chemical composition on the stainless steel substrates. The thin films were characterized in terms of their microstructure, crystal...
-
Electromagnetic forced vibrations of composite nanoplates using nonlocal strain gradient theory
PublikacjaThis article is intended to analyze forced vibrations of a piezoelectric-piezomagnetic ceramic nanoplate by a new refined shear deformation plate theory in conjunction with higher-order nonlocal strain gradient theory. As both stress nonlocality and strain gradient size-dependent effects are taken into account using the higher-order nonlocal strain gradient theory, the governing equations of the composite nanoplate are formulated....
-
Experimental Investigations of Forced Convection of Nanofluids in Smooth, Horizontal, Round Tubes: A Review
PublikacjaA comprehensive review of published works dealing with experimental studies of forced convection heat transfer of nanofluids is presented. The survey is limited to straight, smooth, and round tubes. Moreover, only mono nanofluids exhibiting Newtonian behaviour are considered. Works on experimental research of forced convection in tubes are presented in a chronological order in the first part of the article. In this part, attention...
-
Impact of Temperature and Nanoparticle Concentration on Turbulent Forced Convective Heat Transfer of Nanofluids
PublikacjaTheoretical analysis of the influence of nanoparticles and temperature on the average Nusselt (Nu) number and the average heat transfer coefficient (HTC) during the turbulent flow of nanofluid in a horizontal, round tube was carried out. The Nu number is a function of the Reynolds (Re) number and the Prandtl (Pr) number, which in turn are functions of the thermophysical properties of the liquid and the flow conditions. On the other...
-
Experimental investigation of forced convection of water/EGAl2O3 nanofluids inside horizontal tube
PublikacjaIn this paper, forced convection of water/EG-Al2O3 nanofluids inside horizontal stainless steel tube is studied experimentally. As base fluid served water/EG mixture of two ratios (60:50 and 50:50). Nanoparticle mass concentrations was 0.1% or and 1%. Transition and turbulent flow regimes were tested. Average heat transfer coefficient and pressure drop values were determined for nanofluids and compared to base fluids. Deterioration...
-
Experimental investigation of forced convection of water-Al2O3 nanofluids inside horizontal tubes,
PublikacjaIn 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...
-
Homoclinic orbits for an almost periodically forced singular Newtonian system in R^3
Publikacja. 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
-
Tests for lapping of flat surfaces of ceramic elements with forced dosing of abrasive slurry
PublikacjaPrzedstawiono zagadnienia dotyczące systemu wymuszonego dawkowania zawiesiny ściernej w docieraniu jednotarczowym powierzchni płaskich. Opisano zalety takiego systemu dozowania płynnej zawiesiny ściernej. Omówiono wybrane wyniki badań docierania elementów z ceramiki technicznej. Analizowano wpływ podstawowych warunków dawkowania zawiesiny na ubytek liniowy próbek.
-
The study on minimum uncut chip thickness and cutting forces during laser-assisted turning of WC/NiCr clad layers
Publikacja -
Investigation of the Effect of The Temperature and Magnetization Pattern on Flux Density, Instantaneous Torque, Unbalanced Magnetic Forces of a Surface Inset PMM
PublikacjaElectrical machines utilized in domestic applications such as ceiling fans should have low losses and cost. Permanent magnets are used instead of rotor excitation to reduce losses. Therefore, not only the losses of the rotor winding are eliminated, but also the efficiency of the machine is increased. A surface inset consequent pole (SICP) machine has also been used to reduce costs. Because less magnets are utilized in this structure....
-
Application of signal to noise ratio and grey relational analysis to minimize forces and vibrations during precise ball end milling
Publikacja -
Steady-state characteristics and dynamic response of the PEM fuel cell to unit step change of load
PublikacjaPodano opis układu zasilania opartego na dwóch ogniwach paliwowych typu PEM o łącznej mocy 2.4 kW. Zaprezentowano wybrane charakterystyki statyczne i dynamiczne układu.
-
Mixed algorithm in searches of mechanical system steady-state conditions for low precision of the state estimation
PublikacjaW pracy zaprezentowano algorytm poszukiwania rozwiązania układu równań nieliniowych. Nieliniowe funkcje lewych stron znane są z ograniczoną dokładnością, a wzory określające ich pochodne względem czasu nie są znane. Wartości pochodnych wyznaczane są numerycznie za pomocą różnic skończonych. Z uwagi na niską precyzje wyznaczania wartości funkcji, wartości pochodnych znane są jedynie z ograniczoną dokładnością., pochodne zawierają...
-
Analytical-numerical approach to solve the transport equation for steady gradually varied flow in open channel
PublikacjaW pracy przedstawiono metodę rozwiązania równania transportu adwekcyjno-dyfuzyjnego w przypadku ustalonego niejednostajnego przepływu w kanałach otwartych. Metoda wykorzystuje technikę dekompozycji. Do rozwiązania równania adwekcji-dyfuzji zastosowano analityczne rozwiązanie w postaci odpowiedzi impulsowej liniowego równania adwekcji-dyfuzji. Dokonano adaptacji metody dla przypadku ze zmiennymi parametrami. Do rozwiązania drugiej...
-
Analytical ‘Steady-State’-Based Derivation and Clarification of the Courant-Friedrichs-Lewy Condition for Pipe Flow
PublikacjaThis article addresses the problem of choosing the optimal discretization grid for emulating fluid flow through a pipeline. The aggregated basic flow model is linearized near the operating point obtained from the steady state analytic solution of the differential equations under consideration. Based on this model, the relationship between the Courant number (μ) and the stability margin is examined. The numerically set coefficient...
-
Impact of Energy Slope Averaging Methods on Numerical Solution of 1D Steady Gradually Varied Flow
PublikacjaIn this paper, energy slope averaging in the one-dimensional steady gradually varied flow model is considered. For this purpose, different methods of averaging the energy slope between cross-sections are used. The most popular are arithmetic, geometric, harmonic and hydraulic means. However, from the formal viewpoint, the application of different averaging formulas results in different numerical integration formulas. This study...
-
Comparison of Average Energy Slope Estimation Formulas for One-dimensional Steady Gradually Varied Flow
PublikacjaTo find the steady flow water surface profile, it is possible to use Bernoulli’s equation, which is a discrete form of the differential energy equation. Such an approach requires the average energy slope between cross-sections to be estimated. In the literature, many methods are proposed for estimating the average energy slope in this case, such as the arithmetic mean, resulting in the standard step method, the harmonic mean and...
-
Feeding milk replacer instead of whole milk affects blood plasma proteome and lipid profile in preruminant calves
Publikacja -
Non-Newtonian Mathematics Instead of Non-Newtonian Physics: Dark Matter and Dark Energy from a Mismatch of Arithmetics
PublikacjaNewtonian physics is based on Newtonian calculus applied to Newtonian dynamics. New paradigms such as ‘modified Newtonian dynamics’ (MOND) change the dynamics, but do not alter the calculus. However, calculus is dependent on arithmetic, that is the ways we add and multiply numbers. For example, in special relativity we add and subtract velocities by means of addition β1⊕β2=tanh(tanh−1(β1)+tanh−1(β2)), although multiplication β1⊙β2=tanh(tanh−1(β1)⋅tanh−1(β2)),...
-
The influence of rotor-stator axial gap on the aerodynamic forces generatedin the shroud clearance of a turbine stage. Part I: Pressure field
PublikacjaPrzedstawiono wyniki badań doświadczalnych wpływu zmiany luzu osiowego na rozkład ciśnienia w uszczelnieniu nadbandażowym stopnia powietrznej turbiny modelowej. Wykazano, że w przypadku uszczelnienia promieniowego zmiana luzu osiowego nieznacznie zmienia rozkład ciśnienia w szczelinie nadbandażowej w porównaniu ze zmianą mimośrodowości czy skośnego ustawienia osi wirnika względem osi korpusu.
-
Beyond the helium buffer: 12C−2 rotational cooling in cold traps with H2 as a partner gas: interaction forces and quantum dynamics
Publikacjaabstract = { The scattering cross-sections and corresponding rate coefficients for rotationally inelastic collisions of $^{12}$C$_2$^-$ ($^2 \Sigma_g^+$) with H$_2$ ($^1 \Sigma_g^+$) are presented over a broad range of cold-trap temperatures. They have been calculated using quantum scattering theory that employs a new ab initio potential energy surface. The rate coefficients for the inelastic processes in the anionic partner are...
-
Why do G-quadruplexes dimerize through the 5’-ends? Driving forces for G4 DNA dimerization examined in atomic detail
PublikacjaG-quadruplexes (G4) are secondary structures formed by guanine-rich nucleic acid sequences and shown to exist in living cells where they participate in regulation of gene expression and chromosome maintenance. G-quadruplexes with solvent-exposed guanine tetrads show the tendency to associate together through cofacial stacking, which may be important for packaging of G4-forming sequences and allows for the design of higher-order...
-
Molecular dynamics simulations reveal the balance of forces governing the formation of a guanine tetrad—a common structural unit of G-quadruplex DNA
PublikacjaG-quadruplexes (G4) are nucleic acid conformations of guanine-rich sequences, in which guanines are arranged in the square-planar G-tetrads, stacked on one another. G4 motifs form in vivo and are implicated in regulation of such processes as gene expression and chromosome maintenance. The structure and stability of various G4 topologies were determined experimentally; however, the driving forces for their formation are not fully...
-
Forced degradation studies of ivabradine and in silico toxicology predictions for its new designated impurities
PublikacjaAll activities should aim to eliminate genotoxic impurities and/or protect the API againstdegradation. There is a necessity to monitor impurities from all classification groups,hence ivabradine forced degradation studies were performed. Ivabradine was provedto be quite durable active substance, but still new and with insufficient stability data.Increased temperature, acid, base, oxidation reagents and...
-
Nonlinear Free and Forced Vibrations of a Hyperelastic Micro/Nanobeam Considering Strain Stiffening Effect
PublikacjaIn recent years, the static and dynamic response of micro/nanobeams made of hyperelasticity materials received great attention. In the majority of studies in this area, the strain-stiffing effect that plays a major role in many hyperelastic materials has not been investigated deeply. Moreover, the influence of the size effect and large rotation for such a beam that is important for the large deformation was not addressed. This...
-
Multistage Coupling of Eight Mistuned Bladed Disk on a Solid Shaft, Forced Vibration Analysis
Publikacja -
Forced Degradation Studies of Ivabradine and In Silico Toxicology Predictions for Its New Designated Impurities
PublikacjaAll activities should aim to eliminate genotoxic impurities and/or protect the API against degradation. There is a necessity to monitor impurities from all classification groups, hence ivabradine forced degradation studies were performed. Ivabradine was proved to be quite durable active substance, but still new and with insufficient stability data. Increased temperature, acid, base, oxidation reagents and light were found to cause...
-
Reconstruction of dopant vertical position from Kelvin probe force microscope images
Publikacja -
Comparison of numerical models of impact force for simulation of earthquake-induced structural pounding
PublikacjaW artykule przedstawiono porównanie trzech modeli numerycznych służących do symulacji siły zderzenia w czasie kontaktu pomiędzy konstrukcjami budowlanymi podczas trzęsień ziemi. Efektywność każdego z modeli zbadano porównując wyniki analiz numerycznych z wynikami badań eksperymentalnych. Wyniki pracy pokazują, iż nieliniowy model lepkosprężysty najdokładniej symuluje przebieg czasowy siły zderzenia w czasie kontaktu.