Search results for "Drag"
showing 10 items of 179 documents
Technical Note: Sensitivity of 1-D smoke plume rise models to the inclusion of environmental wind drag
2010
Abstract. Vegetation fires emit hot gases and particles which are rapidly transported upward by the positive buoyancy generated by the combustion process. In general, the final vertical height that the smoke plumes reach is controlled by the thermodynamic stability of the atmospheric environment and the surface heat flux released by the fire. However, the presence of a strong horizontal wind can enhance the lateral entrainment and induce additional drag, particularly for small fires, impacting the smoke injection height. In this paper, we revisit the parameterization of the vertical transport of hot gases and particles emitted from vegetation fires, described in Freitas et al. (2007), to in…
Inner Edge Drag by an Asynchronous Primary and Accretion Disc Structure In Close Binaries
1996
In this work a 3-D ‘Smoothed Particle Hydrodynamics’ ([1]; [4]; [5]) accretion disc is simulated where particles at its inner edge are dragged by a fast spinning compact central star, as in the case of the intermediate polars. The angular velocity of the central star is twice the orbital angular velocity w 0. This drag can be attributed mainly to viscous interaction in the dense compact star atmosphere, although magnetic coupling may also play a role.
Dracocephalum ruyschiana L. (Ogre)
1915
Nordischer Drachenkopf ist find in Oger, Sandhügel an der Lindenbergschen Starsse. /// Ruiša pūķgalve, atradne: Ogre, dienvidu nogāze pie Liepkalnu ielas. /// Northern Dragon-head, deposit: Ogre, southern slope at Liepkalnu street. /// Zīmogs/ stamp: "Legit et Societati Naturae Scrutatorum Rigensi donavit Th. Anders". [Attēls no LU Muzeja kolekcijas Herbarium Latvicum (RIG II); (BOT1029_22).]
The Mean-Field Limit for Solid Particles in a Navier-Stokes Flow
2008
We propose a mathematical derivation of Brinkman's force for a cloud of particles immersed in an incompressible viscous fluid. Specifically, we consider the Stokes or steady Navier-Stokes equations in a bounded domain Omega subset of R-3 for the velocity field u of an incompressible fluid with kinematic viscosity v and density 1. Brinkman's force consists of a source term 6 pi rvj where j is the current density of the particles, and of a friction term 6 pi vpu where rho is the number density of particles. These additional terms in the motion equation for the fluid are obtained from the Stokes or steady Navier-Stokes equations set in Omega minus the disjoint union of N balls of radius epsilo…
Supercritical CO2 extraction of essential oil from orange peel; effect of the height of the bed
2000
Abstract The influence of the height of the particle bed on the kinetics of supercritical fluid extraction (SFE) of essential oil from orange peel is analyzed in this article. Peel of dehydrated oranges of the satsuma and naveline cultivars was used. A series of experiments were designed wherein, for the same conditions, particle height varied widely. These experiments were also carried out on different scales with extraction volumes of 0.5 and 5 l. The results of the experiments were interpreted using Sovova's extended flow model as has been done in previous studies. The bibliography indicates that a number of phenomena may distort the process. One of these phenomena is the formation of ma…
CFD Simulation of Particle Distribution in a Multiple-impeller High-Aspect-Ratio Stirred Vessel
2000
Publisher Summary This chapter describes fully predictive simulations of solid–liquid suspensions in a high-aspect-ratio, multiple-impeller stirred tank. These are performed by using the Inner Outer impeller modeling technique coupled with the Multi Fluid Model (MFM) for the treatment of the dispersed phase. The strongly simplified Settling Velocity Model (SVM) is also tested. The effects of free-stream turbulence on the drag coefficient CD and particle settling velocity are accounted for by means of a recently proposed correlation. Comparison of simulation results with experimental particle concentration profiles shows that the MFM approach leads to fair agreement with experimental data. R…
Le cimetière du second âge du Fer du « Bas des Aouches » à Gisy-les-Nobles (Yonne) : découvertes anciennes et fouilles modernes
2015
Die Untersuchung betrifft die Metallfunde einer zufällig am Ende des 19. Jahrhunderts entdeckten Nekropolesowie die Reste von Körpergräbern, die 1978 am gleichen Fundplatz ausgegraben wurden. Trotz der Dürftigkeit der Informationenermöglichen die Funde eine Unterteilung in chronologische Phasen, die vom zweiten Viertel des 5. Jh. v. Chr. bis zu den letztenJahrzehnten des 3. Jh. v. Chr. reichen und den bereits bekannten Daten des regionalen Bestattungswesens entsprechen
"Belye lilii" : genezis finskogo mifa v bolgarii, rol' russkogo fennofil'stva, finsko-bolgarskie kontakty i posredniki s konca XIX do konca XX veka
2004
Liilia Siibergin väitöstyössä osoitetaan, miten suomalaisista on kirjallisuuden kautta Bulgariassa tullut sankareita, joita kohtaan tunnetaan erityistä sympatiaa. Samalla suomalaisista sinkoutuu pois kaikki, mikä voisi viitata epätäydellisyyteen. – Emme enää voi puhua stereotypiasta, vaan kyseessä on kansallismyytti, Siiberg toteaa. Bulgarialaisilla ei kuitenkaan ole erityisasemaa suomalaisten mielissä. Väitöskirjassa tarkastellaan Suomen ja Bulgarian välisten kulttuuri- ja kirjallisuussuhteiden syntymistä ja kehitystä sekä tutkitaan kanssakäymisen erityispiirteitä vertailevan kirjallisuustieteen ja kulttuurintutkimuksen näkökulmasta. Siibergin esittämä malli Suomen kansallismyytin syntymis…
Phytochemical and anti-staphylococcal biofilm assessment of Dracaena draco L. Spp. draco resin
2013
Background: Dracaena draco L. ssp. draco is known as the “dragon's blood tree” and it is endemic from the Canary Islands and Morocco. Objective: Carry out phytochemical investigation of acetonic extracts of red resin obtained from the trunk of D. draco, to obtain to the isolation of the most abundant resin constituents, belonging to the class of flavonoids: flavans, along with homoisoflavans and homoisoflavanones. Materials and Methods: The structures of the isolated compounds were established by Nuclear Magnetic Resonance (NMR) and mass spectrometry data and comparison with literature data. The acetonic extract was evaluated for its anti-staphylococcal properties against two reference stra…
Apocryphal Passions of the Apostles in Croatian Glagolitic Texts
2020
In the course of the Middle Ages, apocryphal and hagiographic texts of The Acts of the Apostles of various origins became part of the Croatian Glagolitic literature. The Passion of Saint Andrew, for example, is documented in the sanctorale of nineteen Croatian Glagolitic breviaries dating from the period between the 14th and mid-16th centuries. The Glagolitic Passion is an abbreviated translation of the Latin Epistula presbyterorum et diaconorum Achaiae (BHL 428) from the 6th century. The texts of the Passion of Jamesthe Apostle (Jacobus Maior, apost., filius Zebedaei, frater Johannis, Passio, BHL 4057) are found in two Glagolitic breviaries, namely the Breviary of Vitus of Omi?alj (1396) a…