noun
definition
A form of lava flow associated with Hawaiian-type volcanoes, consisting of basaltic rock, usually dark-colored with a jagged and loose, clinkery surface. Compare pahoehoe.
Examples of aa in a Sentence
The southeastern corner of the province is traversed by the Westerwolde Aa, which discharges into the Dollart.
The three chief rivers of the province are the Elbe in the north-east, where it mainly forms the boundary and receives the navigable tributaries Jeetze, Ilmenau, Seve, Este, Luhe, Schwinge and Medem; the Weser in the centre, with its important tributary the Aller (navigable from Celle downwards); and in the west the Ems, with its tributaries the Aa and the Leda.
The surface of the upper slopes of Mauna Loa is almost wholly of two widely different kinds of barren lava-flows, called by the Hawaiians the pahoehoe and the aa.
The aa is lava broken into fragments having sharp and jagged edges.
As the same stream sometimes changes abruptly from one kind to the other, the two kinds must be due to different conditions affecting the flow, and among the conditions which may cause a stream to break up into the aa have been mentioned the greater depth of the stream, a sluggish current, impediments in its course just as it is granulating, and, what is more probable, subterranean moisture which causes it to cool from below upward instead of from above downward as in the pahoehoe.
I checked last night on the AA site using their route planner to double check on our route over.
If a rectangle be constructed about AA' and BB', the diagonals of this figure are the "asymptotes" of the curve; they are the tangents from the centre, and hence touch the curve at infinity.
This wand takes two AA batteries, which are not included.
Basically, they are Nickel-Cadmium AA batteries with an average 600 to 1500 mAH capacity, which designates how long a charge the batteries can hold when not plugged directly into a power source.
If, ignoring temporarily and for simplicity the fact that part of the carbon may exist in the state of graphite, we consider the behaviour of iron in cooling from the molten state, AB and BC give the temperature at which, for any given percentage of carbon, solidification begins, and Aa, aB, and Bc that at which it ends.
As freezing progresses, at each successive temperature reached the frozen austenite has the carbon-content of the point on Aa which that temperature abscissa cuts, and the still molten part or " mother-metal " has the carbon-content horizontally opposite this on the line AB.
In other words, the composition of the frozen part and that of the mother-metal respectively are p and q at the beginning of the freezing, and r and t' at the end; and during freezing they slide along Aa and AB from p to r and from q to t'.
That removal progressively raises the melting-point of the metal, after line Aa of fig.
The Aµ from C to F being taken as unity in each case then the AA's for the other regions of the spectrum are expressed in fractions A A (C to F) and are given under the asterisks.
In Germany there are the Westphalian Aa, rising in the Teutoburger Wald, and joining the Werre at Herford, the Munster Aa, a tributary of the Ems, and others.
Let AB be the shortest distance between the lines of action, and let AA, BB
Resolving AA,
It is evident, in the first place, that in any displacement common to the two surfaces, the work of the two equal and opposite normal pressures will cancel; moreover if, one of the surfaces being fixed, an infinitely small displacement shifts the point of contact from A to B, and if A be the new position of that point of the sliding body which was at A, the pro jectior of AA on the normal at A is of the second order.
Let the centre of R C pressure C at the first joint aa be known, and also the b a pressure P acting at C in C,
The terrible power of excommunication is claimed for the church; but the council of the realm also is called to use the power given them by God to put down all religion but the reformed, and to further the aims and carry out the sentences AA.
This film, however, tends to contract on itself, and the loose strip of metal BB will, if it is let go, be drawn up towards AA, provided it is sufficiently light and smooth.
Hence if F is the force by which the slip BB is pulled towards AA, F =d b T ab =Ta,..
Courland is drained by nearly one hundred rivers, of which only three, the Dvina, the Aa and the Windau, are navigable.
In Aristotle, again, the principle which sets all nature under the rule of thought, and directs it towards a rational end, is vows, or the divine spirit itself; while Aoyos is a term with many senses, used as more or less identical with a number of phrases, ou €v€Ka, ivEpyaaa, ivr€X aa, ovwia, e hos, popcIA, &c.
The mean sea-level is shown by the horizontal line aa, dotted where it passes through the land, and the natural mean level of saturation bb, above the sea-level, by a curved dot and dash line.
These fissures are in vertical planes stretching entirely across the puddle trench, and reaching in one case, aa, nearly to the highest level at which the reservoir had been worked for seventeen years after the leakage had been discovered.
If a line S2 cut an arc aa at b, so that the two segments ab, ba lie on opposite sides of the line, then projecting the figure so that the line Sl goes off to infinity, the tangent at b is projected into the asymptote, and the arc ab is projected into a hyperbolic leg touching the asymptote at one extremity; the arc ba will at the same time be projected into a hyperbolic leg touching the same asymptote at the other extremity (and on the opposite side), but so that the two hyperbolic legs may or may not belong to one and the same branch.
Next, if the line S2 touch at b the arc aa so that the two portions ab, ba lie on the same side of the line Sl, then projecting the figure as before, the tangent at b, that is, the line S2 itself, is projected to infinity; the arc ab is projected into a parabolic leg, and at the same time the arc ba is projected into a parabolic leg, having at infinity the same direction as the other leg, but so that the two legs may or may not belong to the same branch.
It is obvious that the curve is symmetrical about AA'.
If AA' be bisected at C, and the line BCB' be drawn perpendicular to AA', then it is readily seen that the curve is symmetrical about this line also; since if we take S' on AA' so that S'A' =SA, and a.
Let AA' be the axis and S, S' the foci.
Take a piece of thread of length AA', and fix it at its extremities by means of pins at the foci.
The AA is proud to have the benefit of an active and participatory democracy.
I have aa 4-year degree in business and am a real estate investor.
The third match, where a* matches aa, is interesting.
Escape it the tote system or get a including the aa.
Much less than least aa by is necessary or.
As I said in my first post I'm really just looking for deals on bulk purchase of high mha aa and aaa batteries.
Ay, it's spring again, WI aa the twists an turns that Mother Nature can throw at's.
I hae the answer tae aa oor problems. ' ' Whit dae ye mean?
The world o aa the senses is the same.
Fit ill is there in a bawd, efter aa?
We war treated tae " Scots Wha Hae " an " A Man's a Man fur aa That " .
Membership is open to all clubs affiliated to the South of England AA.
Richard Archibald from Ballymoney Gled tae finally hear fae sae many Scotch folk that're aa fired up aboot thair ain leid.
The shared experiences of active alcoholism at AA meetings make up a bond among all members of Alcoholics Anonymous.
Map Map of Sicily, Italy [Based on AA Europe road Atlas, 1997] .
By the time he got a call from an old drinking buddy in 1934, Wilson had, in AA parlance, hit bottom.
The diagnosis of amyloidosis is histological, ie proof of AA amyloid deposition in biopsy material.
The AA also provides a booklet for disabled drivers traveling in Europe, which is quite useful.