diffusion

Definitions

  • WordNet 3.6
    • n diffusion the act of dispersing or diffusing something "the dispersion of the troops","the diffusion of knowledge"
    • n diffusion the property of being diffused or dispersed
    • n diffusion the spread of social institutions (and myths and skills) from one society to another
    • n diffusion (physics) the process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration
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Webster's Revised Unabridged Dictionary
  • Interesting fact: You can see a candle flame from 50 Kilometers on a clear, dark night. You can hear the tick of a watch from 6 meters in very quiet conditions. You can taste one gram of salt in 500 liters of water (.0001M). You can detect one drop of perfume diffused throughout a three-room apartment. You can detect the wing of a bee falling on your cheek from a height of one centimeter.
    • Diffusion The act of diffusing, or the state of being diffused; a spreading; extension; dissemination; circulation; dispersion. "A diffusion of knowledge which has undermined superstition."
    • Diffusion (Physiol) The act of passing by osmosis through animal membranes, as in the distribution of poisons, gases, etc., through the body. Unlike absorption, diffusion may go on after death, that is, after the blood ceases to circulate.
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Century Dictionary and Cyclopedia
    • n diffusion The act of diffusing, or the state of being diffused. The gradual and spontaneous molecular mixing of two fluids which are placed in contact one with the other. It takes place without the application of external force and even when opposed by the action of gravity. It is explained by the motion and mutual attraction of the molecules of the two fluids. Diffusion is most rapid and marked between gases, but is also an important phenomenon of liquids. See diffusion of gases and diffusion of liquids, below.
    • n diffusion A scattering, dispersion, or dissemination, as of dust or seed, or of animals or plants.
    • n diffusion Propagation or spread, as of knowledge or doctrine.
    • n diffusion Diffuseness; prolixity.
    • n diffusion Conduction of heat.
    • n diffusion Synonyms Spread, circulation, expansion, dissemination, distribution.
    • n diffusion In psychology, the law, formulated by A. Bain, that “according as an impression is accompanied with feeling, the aroused currents diffuse themselves freely over the brain, leading to a general agitation of the moving organs, as well as affecting the viscera.”
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Chambers's Twentieth Century Dictionary
    • ns Diffusion a spreading or scattering abroad: extension: distribution: in the case of gases or liquids in contact, mixture through each other
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Quotations

  • Sam Houston
    Sam Houston
    “The benefits of education and of useful knowledge, generally diffused through a community, are essential to the preservation of a free government.”
  • George Eliot
    George%20Eliot
    “Gossip is a sort of smoke that comes from the dirty tobacco-pipes of those who diffuse it: it proves nothing but the bad taste of the smoker.”

Etymology

Webster's Revised Unabridged Dictionary
L. diffusio,: cf. F. diffusion,
Chambers's Twentieth Century Dictionary
L. diffundĕre, diffūsumdif (= dis), asunder, fundĕre, to pour out.

Usage

In literature:

Flora, who had seemed enchanting in all she said and thought, was diffuse and silly.
"Little Dorrit" by Charles Dickens
We have heard of a Society for the Diffusion of Useful Knowledge.
"Walking" by Henry David Thoreau
The universal effect of the diffusion of the more potent instruments of warfare in Africa is the same as among ourselves.
"Missionary Travels and Researches in South Africa" by David Livingstone
The centre of diffusion was the Bailey household.
"The New Machiavelli" by Herbert George Wells
The bearing of these considerations upon the origin and diffusion of barbaric myths is obvious.
"Myths and Myth-Makers" by John Fiske
Indeed, amid all the joy which Nana now quite naturally diffused, Fontan alone remained unmoved.
"Nana, The Miller's Daughter, Captain Burle, Death of Olivier Becaille" by Emile Zola
The dark fir-woods spread around us, and their odourous breath was diffused through the cool, still air.
"Fisherman's Luck" by Henry van Dyke
For the diffusion of knowledge.
"History of the Conflict Between Religion and Science" by John William Draper
A faint glow of light diffused itself through the opening.
"The Adventures of Jimmie Dale" by Frank L. Packard
Wide ranging, much diffused, and common species vary most.
"On the Origin of Species" by Charles Darwin
Diffuse all the knowledge the earth contains equally over all mankind to-day, and some men will be wiser than the rest to-morrow.
"Zanoni" by Edward Bulwer Lytton
Such plants seem exposed to such much greater difficulties in diffusion.
"More Letters of Charles Darwin" by Charles Darwin
By the diffusion of works of art?
"The Complete Essays of C. D. Warner" by Charles Dudley Warner
Owen founded several short-lived journals to diffuse his theories.
"The Idea of Progress" by J. B. Bury
The lectures are written in simple style, but suffer from diffuseness.
"Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3" by Various
You felt well and happy whilst I was sitting near you, diffusing warmth through your frame.
"The Serapion Brethren," by Ernst Theodor Wilhelm Hoffmann
What knowledge and power would not the diffusion of this uniform harmony throughout nature demand!
"A Philosophical Dictionary, Volume 8 (of 10)" by François-Marie Arouet (AKA Voltaire)
That life which flows from the head is diffused through the whole body by the various and harmonious action of all the parts.
"The Expositor's Bible: Colossians and Philemon" by Alexander Maclaren
These ideas circulated in a diffuse state till 1793.
"Contemporary Socialism" by John Rae
This is in marked contrast to the cases of diffuse endocarditis where the reaction is rarely present.
"Arteriosclerosis and Hypertension:" by Louis Marshall Warfield
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In poetry:

One autumn day, when hedges yet were green,
And thick-branched trees diffused a leafy gloom,
Hard by where Avon rolls its silvery tide,
I stood in silent thought by Shakspeare's tomb.
"The Church At Stratford-On-Avon" by Horatio Alger Jr
'Tis like the ointment shed
On Aaron's sacred head,
Divinely rich, divinely sweet;
The oil through all the room
Diffused a choice perfume,
Ran through his robes, and blessed his feet.
"Psalm 133" by Isaac Watts
Past and future, hence away!
Joy, diffused throughout the earth,
Centre in this moment's mirth
Of ecstatic holiday:
Once in all their lives' dark story,
Touch them, Fate! with April glory.
"The Street-Children's Dance" by Mathilde Blind
One favour'd son engaged his tenderest care;
One pious youth his whole affection crown'd;
In his young breast the virtues sprung so fair,
Such charms display'd, such sweets diffused around.
"Elegy XV. In Memory of a Private Family in Worcestershire" by William Shenstone
O say what soft propitious hour
I best may chuse to hail thy power,
And court thy gentle sway?
When Autumn, friendly to the Muse,
Shall thy own modest tints diffuse,
And shed thy milder day.
"Hymn To Content" by Anna Laetitia Aikin Barbauld
Forth Spring! The vernal breaths of sunny lands
O'er earth diffuse. The bursting bud expands,
And welcome leaves, lured by the sunlight sheen,
To lustful bask spread forth their cheerful green.
"Spring" by George Hannibal Temple

In news:

Beleaguered HR colleagues, we are confused, abused, diffused and not amused.
Javier Mariscal's Solea sconce with white-glass inner diffuser and rolled-glass outer panels by Leucos, 732-225-0010.
Occupiers' diffuse anger isn't getting the movement where it needs to go.
Jeff Giles 6 hours ago diffuser.fm.
Diffusion has been called in by SumUp to launch its mobile payment system in the UK and Ireland following a competitive pitch.
Diffusion called in for SumUp mobile commerce launch.
Hypertrophic cardiomyopathy most commonly presents in a symmetric,diffuse form.
Tam suspension light in lacquered aluminum with methacrylic diffusers by Marset, 646-727-4250.
Seven Cups, a traditional Chinese teahouse right here in the Old Pueblo, exudes elegance and a kind of diffuse spiritualism.
Diffusion tensor imaging (DTI) is a rapidly growing area of interest in radiology research.
Applications of diffusion tensor imaging and fiber tractography.
Diffusion tensor imaging (DTI) and fiber tractography may prove useful in clinical neuroradiology practice in several categories of disease.
Smudging Around Air Distribution Diffusers.
Items Tagged with 'dirt collecting around ceiling diffusers'.
The problem of dirt collecting around ceiling diffusers has been a concern in the air distribution industry for a long time.
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In science:

For longer residence times, mixing by diffusion of fluid particles with different entry times occurs at locations where the patch has been compressed down to the diffusion scale at which stretching and diffusion balance – the Batchelor scale [19, 41, 42].
Measures of mixing quality in open flows with chaotic advection
Microscopic diffusion (gravitational settling) of chemical species is accounted for using the approximation of Paquette et al. (1986) for the microscopic diffusion coefficient and the expressions given by Montmerle & Michaud (1976) for the microscopic diffusion velocity.
Lithium abundances and extra mixing processes in evolved stars of M67
Hence, these results show that anomalous diffusion is not expected to be observed at long times scales (around 0.1 ms) as soon as the obstacles diffuse, even with diffusion coefficient comparable to that of the tracer molecule.
Anomalous subdiffusion due to obstacles : A critical survey
Finally, in the case of diffusing obstacles, the distributions are qualitatively similar to the immobile case when diffusion is Brownian (Fig. S3A1), but with anomalous diffusion the power law-distributed long time tails observed above are much less obvious (Fig. S3A2).
Anomalous subdiffusion due to obstacles : A critical survey
A simple modification here would be choosing image diffusivity as a function of image gradient itself. In such case, the diffusion becomes non-linear diffusion and the gradient function becomes an “edgestopping” function.
Undithering using linear filtering and non-linear diffusion techniques
In the diffusion term, κ denotes the kinematic molecular diffusivity, and the dynamic diffusivity, ρκ, is basically independent of ρ (i.e., κ ∝ ρ−1 ).
The Pollution of Pristine Material in Compressible Turbulence
We finally consider the model by Villermaux and Duplat (2003), which was motivated by a turbulent mixing picture with three related processes: the generation of pollutant sheets by turbulent stretching, the diffusion of the pollutant sheets by molecular diffusivity and the merging of the diffused sheets.
The Pollution of Pristine Material in Compressible Turbulence
For example the second order term ∇ · (D∇(τ x(s, t)))) describes the diffusion, where the matrix D(s, t) describes the preferred direction of diffusion at location s and time t. A spatial random field with a non-constant diffusion matrix D(s) is shown in Figure 4.
Think continuous: Markovian Gaussian models in spatial statistics
It turns out that diffusive, super-diffusive or sub-diffusive regimes can occur.
Continuity and anomalous fluctuations in random walks in dynamic random environments: numerics, phase diagrams and conjectures
The areas of those sections in gray, black and striped correspond to sub-diffusive, super-diffusive and diffusive regimes, respectively.
Continuity and anomalous fluctuations in random walks in dynamic random environments: numerics, phase diagrams and conjectures
The crosses, the dots, and the black squares mean that for the corresponding (ρ, γ ) points our test gave an exponent equal (diffusive), bigger (super-diffusive), or smaller (sub-diffusive) than 1/2, respectively.
Continuity and anomalous fluctuations in random walks in dynamic random environments: numerics, phase diagrams and conjectures
For HD 122563 no observable difference is found between diffusion and non-diffusion models for giants, except a small effect on the age of the star, i.e., for the same parameters the model with diffusion fits the observational data with an age ∼0.3 Gyr older than the non-diffusion model.
Fundamental properties of the Population II fiducial stars HD 122563 and Gmb 1830 from CHARA interferometric observations
L), the diffusion probability is the solution of a classical diffusion equation D∆P = ∂P /∂ t where D is the diffusion coefficient taken here at the Fermi level, D = vF le/3.
Persistent Currents for Interacting Electrons: a Simple Hartree-Fock Picture
Self-diffusion coefficient The mean square displacement (cid:10)(r(t) − r(0))2 (cid:11) grows linearly with time t, indicating a normal diffusion behaviour and allowing the calculation of the diffusion coefficient D.
Random tiling quasicrystals in three dimensions
The theoretical treatment of anomalous diffusion, namely diffusion processes either faster or slower than ordinary Brownian diffusion, is an active field of research. A well known case of superdiffusion is given by the diffusion processes of L´evy type .
The Levy diffusion as an effect of sporadic randomness
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