Search results for "dynamics"
showing 10 items of 9782 documents
Enhancement of immunohistochemical staining
1982
The present paper describes two simple procedures which enhance immunohistochemical staining. One is to cover the sections with a plastic film to keep the serum uniformly distributed and minimize its evaporation. Secondly, rocking of the slides has been introduced, causing the serum to flow back and forth under the plastic film. Using this system, it has been possible to test for the effect of mixing on an immunohistochemical reaction (the demonstration of calcitonin in thyroid C cells). It has been found that mixing definitely enhances the reaction during the first 8 h. No effect of serum volume was observed.
Mortality of ruptured abdominal aortic aneurysm with selective use of endovascular repair
2009
The aim of this review was to examine the results over a seven-year period of treatment for ruptured abdominal aortic aneurysm (RAAA). From 2002 on, our tertiary referral centre offered both open and endovascular (EVAR) treatment modalities for RAAA. All patients with a proven RAAA who were admitted into our hospital were included. Primary outcome measure was surgical mortality. In total 261 patients were admitted with suspicion of acute AAA. Of these, 175 (67%) had a RAAA, confirmed by computed tomography-scanning or at laparotomy. One hundred and fifty-nine patients (90.9%) were treated, 114 by open repair and 45 by EVAR. Overall mortality of patients treated was 25.2%, with an open repai…
Iterative momentum relaxation for fast lattice-boltzmann simulations
1999
Lattice-Boltzmann simulations are often used for studying steady-state hydrodynamics. In these simulations, however, the complete time evolution starting from some initial condition is redundantly computed due to the transient nature of the scheme. In this article we present a refinement of body-force driven lattice-Boltzmann simulations that may reduce the simulation time significantly. This new technique is based on an iterative adjustment of the local body-force and is validated on a realistic test case, namely fluid flow in a static mixer reactor.
Modelling and Simulation of Gas–liquid Hydrodynamics in a Rectangular Air-lift Reactor
2013
Abstract Computational Fluid Dynamics is a quite well established tool for carrying out realistic simulations of process apparatuses. However, as a difference from single phase systems, for multiphase systems the development of CFD models is still in progress. Among the two-phase systems, gas–liquid systems are characterised by an additional complexity level, related to the fact that bubble sizes are not known in advance, being rather the result of formation and breakage-coalescence dynamics and therefore of complex phenomena related to flow dynamics and interfacial effects. In the present work, Euler–Euler Reynolds-averaged flow simulations of an air-lift reactor are reported. All bubbles …
Casimir-Polder force density between an atom and a conducting wall
2007
In this paper we calculate the Casimir-Polder force density (force per unit area acting on the elements of the surface) on a metallic plate placed in front of a neutral atom. To obtain the force density we use the quantum operator associated to the electromagnetic stress tensor. We explicitly show that the integral of this force density over the plate reproduces the total force acting on the plate. This result shows that, although the force is obtained as a sum of surface element-atom contributions, the stress-tensor method includes also nonadditive components of Casimir-Polder forces in the evaluation of the force acting on a macroscopic object.
The Complex System Theory for the Analysis of Inter-Firm Networks: A Literature Overview and Theoretic Framework
2011
In this paper we discuss the body of knowledge known as complex system theory and its relevance to the analysis of inter-firm networks. We start by addressing the development of systems thinking. Through a literature overview, we point out the main elements for the development of systemic thought from its beginning, through its application in business sciences, to the birth of Complex Systems Theory (CST). With these initial annotations we provide an introduction to the concepts of the complex systems theory. We will underscore those aspects of CST that can be useful to analyze inter-firm networks, in order to highlight the evolutionary dynamics of the networks and to clarify the logical li…
Aplicação do conceito One Health na área hiperendêmica de fasciolíase humana do Altiplano Boliviano: biologia dos limneídeos, dinâmica populacional, …
2021
Abstract Fascioliasis is a freshwater snail-borne zoonotic disease. The Northern Bolivian Altiplano is a very high altitude endemic area where the highest human prevalences and intensities have been reported. Preventive chemotherapy by treatment campaigns is yearly applied. However, liver fluke infection of cattle, sheep, pigs and donkeys assures endemicity and consequent human infection and re-infection risks. A One Health action has therefore been implemented. Activity concerns lymnaeid vectors and environment diversity. Studies included growth, egg-laying and life span in laboratory-reared lymnaeids. Different habitat types and influencing factors were assessed. All populations proved to…
Dielectric polarization and polarizability of 1-pentanol+n-octane mixtures from static dielectric constant and refractive index data at 0,25 and 45�C
1990
Static dielectric constants and refractive indices of 1-pentanol+n-octane mixtures were measured in the temperature range between 0 and 45°C. Data discussed in terms of Kirkwood correlation factor and Lorentz-Lorenz molar refractivity give information on the short range intermolecular interactions between the components. The role played by the nonpolar n-octane in the destruction of 1-pentanol oligomers is also pointed out.
The deformation tensor ∊ of the spin transition in the mixed crystal [Fe0.46Zn0.54(ptz)6](BF4)2
2004
The conversion of the spin state of complexes exhibiting thermal spin crossover from the1A1low-spin (LS) state to the5T2high-spin (HS) state is accompanied by a deformation of the lattice due to the larger bond lengths in the HS state as compared with the LS state. In a previous work [Kuszet al.(2000).J. Appl. Cryst.33, 201–205], it has been shown that the deformation of the lattice, corrected for its temperature dependence, can be described by an almost temperature-independent tensor ∊ multiplied by the fraction of molecules in the HS state, γHS. Here the dependence of ∊ in a mixed single crystal of [Fe0.46Zn0.54(ptz)6](BF4)2(ptz = propyltetrazole) with a transition temperature near 110 K …
A theoretical determination of the dissociation energy of the nitric oxide dimer
1994
Multi-reference CI methods have been applied to determine the dissociation energy and structure of thecis-N2O2 molecule. The convergence of the theoretical result has been checked with respect to a systematic expansion of the one-electron basis set and the multi-reference CI wave function. The best calculated value, 13.8 kJ/mol, is in agreement with the experimental value, 12.2 kJ/mol. It has been obtained with an extended ANO-type basis set [6s5p3d2f], including the effect of the basis set superposition error (BSSE) in the geometry optimization, and additional effects, such as the electron correlation of core electrons and relativistic corrections, using the average coupled pair functional…