There was evaporation of water from the leaf.
The annual evaporation from water surfaces is from 60 to 150 in.
The test tube is tightly corked to prevent evaporation, and allowed to stand for some hours.
The space between the parts of such substances is too large to admit of capillary action; hence the water conveyed to the surface of the soil is prevented from passing upwards any further except by slow evaporation through the mulching layer.
An economical method of evaporation must be found.
The sugar thus produced, by constant stirring and evaporation almost to dryness, forms a species of small-grained concrete.
In endeavouring to make a pan of less power do as much and as good work as one of greater power, they have imagined many ingenious mechanical contrivances, such as currents produced mechanically to promote evaporation and crystallization, feeding the pan from many points in order to spread the feed equally throughout the mass of sugar being cooked, and so on.
It is only known in solution; evaporation of the solution yields the pentoxide.
Cadmium sulphate, CdSO 4, is known in several hydrated forms; being deposited, on spontaneous evaporation of a concentrated aqueous solution, in the form of large monosymmetric crystals of composition 3CdSO 4.8H 2 O, whilst a boiling saturated solution, to which concentrated sulphuric acid has been added, deposits crystals of composition CdSO 4 4H 2 0.
The processes of evaporation and concentration are carried on as they are in a cane sugar factory, but with this advantage, that the beet solutions are freer from gum and glucose than those obtained from sugar-canes, and are therefore easier to cook.
In the upper part of the river the reservoirs are partially protected by curtains of verdure from the effects of the evaporation which makes itself so severely felt on the treeless seaboard.
It is found that in reducing the juice of these two qualities to syrup, fit to pass to the vacuum pans for cooking to crystals, the total amount of evaporation from the degraded j uice is about half that required from the normal juice produced by double crushing.
In the best days of the so-called Jamaica Trains in Demerara, three-quarters of a ton of coal in addition to the megass was burned per ton of sugar made, and with this for many years planters were content, because they pointed to the fact that in the central factories, then working in Martinique and Guadeloupe, with charcoal filters and triple-effect evaporation, 750 kilos of coal in addition to the megass were consumed to make woo kilos of sugar.
Unfortunately no observations of evaporation from the surface of the open sea have been made and very few comparisons of the evaporation of salt and fresh water are on record.
The excess of heat received in equatorial regions expands the water, but at the same time excess of evaporation concentrates it, so that the density increases.
The solution on evaporation deposits a hydrated form, H 2 SiF 6.2H 2 O, which decomposes when heated.
Above the level of the ground-water the soil is kept moist by capillary attraction and by evaporation of the water below, by rainfall, and by movements of the ground-water; on the other hand, the upper layers are constantly losing moisture by evaporation from the surface and through vegetation.
The defecated cane juice, having lost about 70% of its bulk by evaporation in the multipleeffect evaporator, is now syrup, and ready to enter the vacuum pan for further concentration and crystallizaHoward's tion.
In a general way this greater complexity may be said to consist (I) in the restriction of regular absorption of water to those parts of the plant-body embedded in the soil, (2) in the evaporation of water from the parts exposed to the air (transpiration).
Some crystallizers are made entirely cylindrical, and are connected to the condenser of the vacuum pan; in order to maintain a partial vacuum in them, some are fitted with cold-water pipes to cool them and with steam pipes to heat them, and some are left open to the atmosphere at the top. But the efficiency of all depends on the process of almost imperceptible yet continuous evaporation and the methodical addition of syrup, and not on the idiosyncrasies of the experts who manage them; and there is no doubt that in large commercial processes of manufacture the simpler the apparatus used for obtaining a desired result, and the more easily it is understood, the better it will be for the manufacturer.
That evaporation in vacuo, in a multiple-effect evaporator, is advantageous by reason of the increased amount of sugar obtained from a given quantity of juice, and by reason of economy of fuel, there is no doubt, but whether such an apparatus should be of double, triple, quadruple or quintuple effect will depend very much on the amount of juice to be treated per day, and the cost of fuel.
The process of natural evaporation in the salines or salt gardens of the margin of warm seas made the composition of sea-salt familiar at a very early time, and.
Evaporation and subsequent distillation under a high vacuum gives crude glycerin.
In one process the purified ore is disintegrated with hot nitric acid to produce nitrates, which are then converted into sulphates by evaporation with sulphuric acid.
Evaporation of the Juice to Syrup. - The third operation is the concentration of the approximately pure, but thin and watery, juice to syrup point, by driving off a portion of the water in vapour through some system of heating and evaporation.
We can calculate the heat of formation from its ions for any substance dissolved in a given liquid, from a knowledge of the temperature coefficient of ionization, by means of an application of the well-known thermodynamical process, which also gives the latent heat of evaporation of a liquid when the temperature coefficient of its vapour pressure is known.
If it be rubbed in or evaporation be prevented, it acts, like alcohol and chloroform, as an irritant.
The free acid has not been isolated, since on evaporation the solution gradually loses sulphur dioxide.
The use of multiple-effect evaporation made it possible to raise the steam for all the work required to be done in a well-equipped factory, making crystals, under skilful management, by means of the bagasse alone proceeding from the.
Evaporation of the water and anything that lowers the hydrogen-ion concentration have the same effect.
The evaporation of the juice to syrup point.
If, on the other hand, the alcohol be rubbed into the skin, or if its evaporation be prevented - as by a watch-glass - it absorbs water from the tissues and thus hardens them.
annually, but the drainage from the eastern slopes of the Andes is large enough to meet the loss from evaporation and keep these inland lakes from drying up. At an early period this depressed area drained southward to the Colorado, and the bed of the old outlet can still be traced.
The growing demand for this system of evaporation for application in many other industries, besides that of sugar has brought to the front a large number of inventors.
The evaporation which is associated with transpiration is no doubt another, but by themselves they are insufficient to explain the process of lifting water to the tops of tall trees.
in length; with such coils, and a sufficient annular space in the pan free from obstruction, in order to allow a natural down-current of the cooking mass, while an up-current all round is also naturally produced by the action of the heated worms or coils, rapid evaporation and crystallization can be obtained, without any mechanical adjuncts to require attention or afford excuse for negligence.
The impurities occasionally present in commercial citric acid are salts of potassium and sodium, traces of iron, lead and copper derived from the vessels used for its evaporation and crystallization, and free sulphuric, tartaric and even oxalic acid.
The impure glycerin obtained as above is purified by redistillation in steam and evaporation in vacuum pans.
The latter function has been found to be of extreme importance in the case of plants exposed to the direct access of the suns rays, the heat of which would rapidly cause the death of the protoplasts were it not employed in the evaporation of the water.
During the three years he held this position he carried out researches on the contact of elastic solids, hardness, evaporation and the electric discharge in gases, the last earning him the special commendation of Helmholtz.
During the formation of the Schlier the plain was covered by an inland sea or series of salt lakes, in which evaporation led to the concentration and finally to the deposition of the salts contained in the water.
The evaporation from this large basin exercises a certain influence on the climate of the surrounding country, while the absorption of heat for the thawing of the ice has a notable cooling effect in early summer.
Others are deprived of a part of their more volatile constituents by spontaneous evaporation, or by distillation, in vacuo or otherwise, at the lowest possible temperature.
The first volume, Vegetable Staticks (1727), contains an account of numerous experiments in plant-physiology - the loss of water in plants by evaporation, the rate of growth of shoots and leaves, variations in root-force at different times of the day, &c. Considering it very probable that plants draw "through their leaves some part of their nourishment from the air," he undertook experiments to show in "how great a proportion air is wrought into the composition of animal, vegetable and mineral substances"; though this "analysis of the air" did not lead him to any very clear ideas about the composition of the atmosphere, in the course of his inquiries he collected gases over water in vessels separate from those in which they were generated, and thus used what was to all intents and purposes a "pneumatic trough."
In 1899, at Maidstone, special prizes were offered for machines for washing hops with liquid insecticides, cream separators (power and hand), machines for the evaporation of fruit and vegetables, and packages for the carriage of (a) soft fruit, (b) hard fruit.
The proportions of the salts of river and sea-water are quite different, as Julius Roth shows thus: - The salts of salt lakes which have been formed in the areas of internal drainage in the hearts of the continents by the evaporation of river water are entirely different in composition from those of the sea, as the existence of the numerous natron and bitter lakes shows.
In beetroot sugar manufacture the operations are washing, slicing, diffusing, saturating, sulphuring, evaporation, concentration and curing.
What is not used in the constructive processes is employed in the evaporation of the water, the leaf being thus kept cool.
It was this remarkable fact which first led to the idea that, as the rainfall could not be accounted for either by evaporation or by the river discharge, much of the 90% unaccounted for must sink into the ground, and in part be absorbed by some underlying bed-rock.
Of the water received by Albert Nyanza annually (omitting the Victoria Nile from the calculation) between 50 and 60% is lost by evaporation, whilst 24,265,000,000 cubic metres are annually withdrawn by the Bahr-el-Jebel.
In the summer a great accumulation of solar heat takes place on the dry surface soil, from which it cannot be released upwards by evaporation, as might be the case were the soil moist or covered with vegetation, nor can it be readily conveyed away downwards as happens on the ocean.
In the case of a large hollow in a very dry climate the rate of g evaporation may be sufficient to prevent the water from ever rising to the lip, so that there is no outflow to the sea, and a basin of internal drainage is the result.
This serves a double purpose, bringing up from the soil continually a supply of the soluble mineral matters necessary for their metabolic processes, \vhich only enter the plant in solutions of extreme dilution, and at the same time keeping the plant cool by the process of evaporation.
rend., 1891, 112, p. 866) is obtained by mixing a solution of sodium hyposulphite with double its volume of hydrochloric acid, filtering and extracting with chloroform; the extract yielding the variety on evaporation.
About 4,000,000 bottles of water are exported annually, and another article of export is the salt recovered from the water by evaporation.
in a direct line, no perennial tributary but on the contrary loses a great deal of its water by evaporation.
Their skin is a lot drier and oilier due to higher sebum levels and high moisture evaporation rates.
The existence of lakes in hollows of the land depends upon the balance between precipitation and evaporation.
Materials like tar and pitch are sometimes employed as a matrix; they are used hot and without water, the solidifying action being due to cooling and to evaporation of the mineral oils contained in them.
The amount required to combine chemically with the cement is about 16% by weight, but in practice much more than this is used, because of loss by evaporation, and the difficulty of ensuring that the water shall be uniformly distributed.
In 1800 he became a secretary of the society, and in the following year he presented the important paper or series of papers, entitled "Experimental Essays on the constitution of mixed gases; on the force of steam or vapour of water and other liquids in different temperatures, both in Torricellian vacuum and in air; on evaporation; and on the expansion of gases by heat."
Transpiration is loss of water by the plant by evaporation, chiefly from the minute pores or stomata on the leaves.
In taking a slip or cutting the gardener removes from the parent plant a shoot having one or more buds or " eyes," in the case of the vine one only, and places it in a moist and sufficiently warm situation, where, as previously mentioned, undue evaporation from the surface is prevented.
The pathways should be paved with tiles, brick or stone, or made of concrete and cement, and the surface should be gently rounded so that the water required for evaporation may drain to the sides while the centre is sufficiently dry to walk upon; they should also have brick or stone edgings to prevent the water so applied soaking away at the sides and thus being wasted.
Shallow planting, whether of wall trees or standards, is generally to be preferred, a covering of a few inches of soil being sufficient for the roots, but a surface of at least equal size to, the surface of the hole should be covered with dung or litter so as to restrain evaporation and preserve moisture.
The occurrence of red deposits in western Australia, Scotland, the Ural mountains, in Michigan, Montana and Nova Scotia, &c., associated in some instances with the formation of gypsum and salt, clearly points to the existence of areas of excessive evaporation, such as are found in land-locked waters in regions where something like desert conditions prevail.
The increased rainfall;from July to December (the summer and autumn rains), and the increased evaporation in spring and summer (5.2 in.
The above methods give a dilute aqueous solution of hydrogen peroxide, which may be concentrated somewhat by evaporation over sulphuric acid in vacuo.
During the rainy season there is a considerable body of water in these channels, but owing partly to rapid evaporation and partly to the porous character of the soil the surface of the country dries rapidly.
In "cold deserts" the want of vegetation is wholly due to the prevailing low temperature, while in "hot deserts" the surface is unproductive because, on account of high temperature and deficient rainfall, evaporation is largely in excess of precipitation.
The rainfall chiefly occurs in violent cloudbursts, and the soluble matter in the soil is carried down by intermittent streams to salt lakes around which deposits are formed as evaporation takes place.
m., and its depth but comparatively slight (31 to 36 ft.), the evaporation is very appreciable (amounting to 3.2 ft.
Were there no evaporation, this would raise the surface of the sea 51 ft.
In point of fact, however, the entire volume of fresh water poured into the Caspian is only just sufficient to compensate for the loss by evaporation.
By evaporation of a solution of lanthanum oxide in hydrochloric acid to the consistency of a syrup, and allowing the solution to stand, large colourless crystals of a hydrated chloride of the composition 2LaC1 3.15H 2 O are obtained.
It has been contended that irrigation water suffers no change in composition by use, since by evaporation of a part of the pure water the dissolved matters in the remainder would be so increased as to make up for any matters removed.
The mineral is fused with potassium carbonate, and, on cooling, the product is treated with sulphuric acid, the excess of which is removed by evaporation; water is then added and the silica is filtered off.
A western arm has been cut off from the lake by a dyke, and in this arm a thick crust of salt is formed each year after the evaporation of the flood water.
The one is probably derived from the other, most rock salt deposits bearing evidence of having been formed by the evaporation of lakes or seas.
At one time almost the whole of the salt in commerce was produced from the evaporation of sea water, and indeed salt so made still forms a staple commodity in many countries possessing a seaboard, especially those where the climate is dry and the summer of long duration.
The process of the spontaneous evaporation of sea water was studied by Usiglio on Mediterranean water at Cette.
Halite or rock-salt crystallizes in the cubic system, usually in cubes, rarely in octahedra; the cubes being solid, unlike the skeleton-cubes obtained by rapid evaporation of brine.
Deposits of rock-salt have evidently been formed by the evaporation of salt water, probably in areas of inland drainage or enclosed basins, like the Dead Sea and the Great Salt Lake of Utah, or perhaps in some cases in an arm of the sea partially cut off, like the Kara Bughaz, which forms a natural salt-pan on the east side of the Caspian.
sel de 12 heures and sel de 24 heures, show by their English names the use to which they are applied, and the others merely depend for their quality on the length of time which elapses between successive " drawings," and the temperature of the evaporation.
With open pans the vapour is free to diffuse itself into the atmosphere, and the evaporation is perhaps more rapid.
In Britain the brine is so pure that, keeping a small stream of it running into the pan to replace the losses by evaporation and the removal of the salt, it is only necessary occasionally (not often) to reject the mother-liquor when at last it becomes too impure with magnesium chloride; but in some works the mother-liquor not only contains more of this impurity but becomes quite brown from organic matter on concentration, and totally unfit for further service after yielding but two or three crops of salt crystals.
Sometimes, to get rid of these impurities, the brine is treated in a large tub-`(bessoir) with lime; on settling it becomes clear and colourless, but the dissolved lime forms a skin on its surface in the pan, retards the evaporation and impedes the crystallization.
Some of the saline springs yield salt enough to render their evaporation profitable.
Broadly speaking the salt consumed in India is derived from four sources: (1) importation by sea, chiefly from England and the Red Sea and Aden; (2) solar evaporation in shallow tanks along the seaboard; (3) the salt lakes in Rajputana; (4) quarrying in the salt hills of the northern Punjab.
At the Kohat mines, and in the salt evaporation works on the sea-coast, with the exception of a few of the Madras factories, the government does not come between the manufacturer and the merchant, except in so far as is necessary in order to levy the duty from the salt as it issues from the factory.
The immediate cause of collapse seems to have been cold, due to the deficiency of oil fuel in the Mount Hooper depot, the reason for which was stated to be evaporation through defective stoppers.
The least trace of damp in the lagging, or of moisture condensed on the surface of the calorimeter, may produce serious loss of heat by evaporation.
In practice, the expenses of upkeep for the year and of manufacturing the crop remain the same whether the canes are rich or poor and whether the crop is good or bad, the power of the factory being limited by its power of evaporation.
A fan blast enters the lower end, and, passing out at the upper end, carries off the vapour produced by the drying of the sugar, and at the same time assists the evaporation.
Good crops, however, can often be grown in such areas without irrigation if attention is paid to the proper circulation of water in the soil and means for retaining it or preventing excessive loss by evaporation.
below the surface, is so strongly saturated with salt (up to 24%) that it is at once conducted to the boiling houses, while that of the others is first submitted to a process of evaporation.
lower than that of the Atlantic on account of evaporation.
Their experiments show that in similar conditions the evaporation of sea-water amounts to from 70 to 91% of the evaporation of fresh water, a fact of some importance in geophysics on account of the vast expanses of ocean the evaporation from which determines the rainfall and to a large extent the heat-transference in the atmosphere.
The tropical maxima of salinity on the poleward side of the trade-winds coincide with the regions of minimum rainfall, high temperature, strong winds and consequently of maximum evaporation.
Evaporation is naturally greatest in the enclosed seas of the nearly rainless subtropical zone such as the Mediterranean and Red Sea.
Where the evaporation is at a minimum, the inflow of rivers from a large continental area and the precipitation from the atmosphere at a maximum, there is necessarily the greatest dilution of the sea-water, the Baltic and the Arctic Sea being conspicuous examples.
The penetration of warmth from the surface is effected by direct radiation, and by convection by particles rendered dense by evaporation increasing salinity.
Differences of density between the waters of enclosed seas and of the ocean are brought about in some instances by concentration of the water of the sea on account of active evaporation, and in other instances by dilution on account of the great influx of land water.
Experiments have also been made with a device in which the air-supply is obtained by the evaporation of liquid air absorbed in asbestos.
The body is continually losing mass by the loss of individual molecules in this way, and this explains the process of evaporation.
The average energy of the molecules of the liquid is accordingly lowered by evaporation.
In this we see the explanation of the fall of temperature which accompanies evaporation.
When a liquid undergoing evaporation is contained in a closed vessel, a molecule which has left the liquid will, after a certain 1 Other processes also help in the conduction of heat, especially in substances which are conductors of electricity.
Thus the process of evaporation is necessarily accompanied by a process of recondensation.
When a stage is reached such that the number of molecules lost to the liquid by evaporation is exactly equal to that regained by condensation, we have a liquid in equilibrium with its own vapour.
Not only was he the first discoverer of the rotifers, but he showed "how wonderfully nature has provided for the preservation of their species," by their tolerance of the drying-up of the water they inhabit, and the resistance afforded to the evaporation of the fluids of their bodies by the impermeability of the casing in which they then become enclosed.
If foodstuffs are to be employed it must be possible to grow them in excess of food requirements, and at a cost low enough to ensure that the price of the alcohol shall be about the same as that 1 The lower calorific value plus the latent heat of evaporation at constant volume.
It dissolves in water with evolution of heat; on evaporation a basic salt, ZrOC1 2.8H 2 0, separates out in star-shaped acicular aggregates.
Correlated with their life in dry situations, the bulk of the tissue is succulent, forming a water-store, which is protected from loss by evaporation by a thickly cuticularized epidermis covered with a waxy secretion which gives a glaucous appearance to the plant.
Many of the smaller streams in the Black Hills lose their waters in their lower courses through seepage and evaporation.
The whole current supplied to the house flows through an electrolytic cell consisting of a glass tube containing two platinum electrodes; the electrolyte is dilute sulphuric acid covered with a thin layer of oil to prevent evaporation.
Iodine dissolves in an aqueous solution of the salt to form a dark brown liquid, which on evaporation over sulphuric acid gives black acicular crystals of the tri-iodide, K1 3.
On saturating a solution of caustic potash with sulphuretted hydrogen and adding a second equivalent of alkali, a solution is obtained which on evaporation in a vacuum deposits crystals of K 2 S.5H 2 O.
It is readily soluble in water, and on evaporation in a vacuum over caustic lime it deposits colourless, rhombohedral crystals of 2KHS.H 2 0.
The excess of reagent is removed by evaporation and a small quantity of a ferric salt added, when a deep red colour is produced.
A few intermont areas in the north-west part of the province have outlet westward by Kla1nath river through the Cascade range and by Pitt river (upper part of the Sacramento) through the Sierra Nevada: a few basins in the south-east have outlet by the Rio Grande to the Gulf of Mexico; a much larger but still narrow medial area is drained south-westward by the Colorado to the head of the Gulf of California, where this large and very turbid river has formed an extensive delta, north of which the former head of the gulf is now cut off from the sea and laid bare by evaporation as a plain below sea-level.
Many streams descend from the ravines only to wither away on the desert basin floors before uniting in a trunk river along the axis of a depression; others succeed in uniting in the winter season, when evaporation is much reduced, and then their trunk flows for a few score miles, only to disappear by sinking (evaporating) farther on.
The benzene layer on evaporation deposits the antipyrine as a colourless crystalline solid which melts at 113° C. and is soluble in water.
In such cases the waters are alkaline, and contain various salts in solution which are deposited as a white rim round the basin towards the end of the summer when the amount of water has been greatly reduced by evaporation.
If the violet solution is allowed to evaporate slowly at ordinary temperatures the sulphate crystallizes out as Cr2(S04)3.15H20, but the green solution on evaporation leaves only an amorphous mass.
When the spark gap is small, the sudden evaporation of the metal has a better chance of filling the interval between the poles, even without the introduction of a self-induction.
Boric acid is also obtained from boronatrocalcite by treatment with sulphuric acid, followed by the evaporation of the solution so obtained.
When a solid such as salt or sugar dissolves in contact with water to form a uniform substance from which the components may be regained by evaporation the substance is called a solution.
Still further evaporation causes these crystals to effloresce and pass into the anhydrous salt.
Thus the results of our investigations based on ideal conceptions are applicable to the real phenomena of evaporation and freezing.
By evaporation and condensation, then, the solvent can pass through this perforated partition, which thus acts as a perfect semi-permeable membrane.
where L, the latent heat of fusion, is the difference between the heats of evaporation for ice and water, and v is the specific volume of the vapour.
If each molecule of the solute combines with a certain number of molecules of the solvent in such a way as to render them inactive for evaporation, we get a lowering of vapour pressure.
Mag., June 1903) of the vapour arising from liquid air at various stages of the evaporation will give an idea of the course of events: - (R.)
When this solution is concentrated by evaporation and cooled down, about five-sixths of the chlorate of potash crystallizes out.
Boracic acid is chiefly found near Volterra, where there is also a little rock salt, but the main supply is obtained by evaporation.
This is the main transpiring tissue, and is protected from direct illumination and consequent too great evaporation.
This is, of course, due to the excess of evaporation over the amount of water supplied by its two feeders, the Amu-darya and the Syrdarya, both of which are seriously drawn upon for irrigation in all the oases they flow through.
Thallic chloride, T1C1 3, is obtained by treating the monochloride with chlorine under water; evaporation in a vacuum gives colourless deliquescent crystals of T1C1,.H20.
Thallic sulphate, T1 2 (SO 4) 3.7H 2 O, and thallic nitrate, Tl(NO 3) 3.8H 2 0, are obtained as colourless crystals on the evaporation of a solution of the oxide in the corresponding acid.
2H 2 O, by concentrating the solution between 15° C. and 20°C.; the other, isomorphous with FeCl 2.4H 2 0, by slow evaporation of the mother liquors from the former.
Red ochre, for which there is only a limited market, is mined on Ormuz, Abu Musa and other islands in the Gulf; salt, as deposits, on Ormuz and Qishm I., and by evaporation, near Mohammerah, Fao and elsewhere on both sides of the Gulf; gypsum is widely distributed throughout the Gulf; iron, as haematite and pyrites, widely found through the Ormuz series.
The Rapid Rise From 25° To 75° May Be Due To Radiation Error From The Hot Water Supply, And The Subsequent Fall Of The Curve To The Inevitable Loss Of Heat By Evaporation Of The Boiling Water On Its Way To The Calorimeter.
The Peculiar Advantage Of The Electric Method Of Callendar And Barnes, Already Referred To, Is That The Specific Heat Itself Is Determined Over A Range Of 8° To 10° At Each Point, By Adding Accurately Measured Quantities Of Heat To The Water At The Desired Temperature In An Isothermal Enclosure, Under Perfectly Steady Conditions, Without Any Possibility Of Evaporation Or Loss Of Heat In Transference.
Evaporation of a solution at ordinary temperatures gives colourless monoclinic prisms of Th(SO 4) 2.9H 2 O, which is isomorphous with uranium sulphate, U(S04)2.9H20.
Another method, which is suitable for volatile liquids or low temperatures, is to allow the liquid to evaporate in a calorimeter, and to measure the quantity of heat required for the evaporation of the liquid at the temperature of the calorimeter and at saturation-pressure.
The second method may be called the method of evaporation.
Bunsen and Kirchhoff (Ann., 1860, 113, p. 337), in the spectroscopic examination of the residues obtained on evaporation of water from a mineral spring at Diirkheim, being characterized by two distinctive red lines.
Evaporation of the aqueous solution at 15° C. deposits a crystalline hydrated hydroxide of composition RbOH 2H 2 O (R.
Another peculiar and very general feature of the drainage system of the state is the presence of numerous so-called river " sinks," where the waters disappear, either directly by evaporation or (as in Death Valley) after flowing for a time beneath the surface.
In wet seasons it overflows its banks and becomes greatly extended in area, discharging its surplus waters into the San Joaquin; but in dry seasons the evaporation is so great that there is no such discharge.
And finally, in the fourth place, except on the coast the disagreeableness of the heat of summer is greatly lessened by the dryness of the air and the consequent rapidity of evaporation.
On boiling gelatinous silica with ammonium polytungstate and evaporating with the occasional addition of ammonia, ammonium silicodecitungstate is obtained as short rhombic prisms. On adding silver nitrate and decomposing the precipitated silver salt with hydrochloric acid, a solution is obtained which on evaporation in a vacuum gives the free acid as a glassy mass.
- Although the trioxide is soluble in hydrofluoric acid, evaporation of the solution leads to the recovery of the oxide unchanged.
In some sections a system of dry-farming, by which the scanty rainfall is protected from evaporation by deep ploughing and mulching the soil, has proved profitable.
In the central and southern portions of the plateau the streams either flow into salt lakes, where their waters pass off by evaporation, or into freshwater lakes, which have no visible outlets.
The great evaporation going on from the surface probably causes a slow vertical circulation in the depth, the salter colder waters sinking, and ultimately escaping to the Indian Ocean.
The wines which remain for a long period in cask gradually lose alcohol and water by evaporation, and therefore become in time extremely concentrated as regards the solid and relatively non-volatile matters contained in them.
As a rule, wines which are kept for many years in cask become very dry, and the loss of alcohol by evaporation - particularly in the case of light wines - has as a result the production of acidity by oxidation.
The sun is sufficiently powerful to cause the evaporation of the water in the grape through the skin without any preliminary loosening of the latter by the action of the botrytis cinerea or any other micro-organism.
In the lowlands it loses much of its volume through evaporation and absorption by the sands, and through irrigation, and in its lower course in New Mexico its bed is frequently dry.
In the valleys there are many small streams whose waters never reach the ocean, but disappear by seepage or evaporation.
R CH R Ciohc R They are weak bases, and the ring system is readily split by evaporation with hydrochloric acid, or by the action of reducing and oxidizing agents.
It may be obtained by extracting powdered gall-nuts with a mixture of ether and alcohol, whereupon the tannin is taken up in the lower layer, which on separation and evaporation yields the acid.
On heating, it begins to decompose at 260-265° C. Barium chlorate, Ba(C103)2, is obtained by adding barium chloride to sodium chlorate solution; on concentration of the solution sodium chloride separates first, and then on further evaporation barium chlorate crystallizes out and can be purified by recrystallization.
Where the surface is ulcerated it may be protected from external violence and placed under favourable conditions for healing by covering it with lint moistened with water and with oil-silk over it to prevent evaporation.
Now we can see the reason for their administration, because the nitrous ether, consisting chiefly of ethyl nitrite, dilates the superficial vessels and thus allows greater escape of heat from the surface; while acetate of ammonia, by acting as a diaphoretic and stimulating the secretion of sweat, increases the loss of heat by evaporation.
When a patient is covered with several blankets, loss of heat from the surface both by radiation and evaporation is to a great extent prevented, but if a cradle be placed over him, so as to raise the bedclothes and allow of free circulation of air around his body, both radiation and evaporation will be increased and the temperature consequently lowered.
If his body be left uncovered except by the sheet or blanket thrown over the cradle, the loss of heat is still greater, and it may be much increased by sponging the surface with either hot or cold water so as to leave it slightly moist and increase evaporation.
From a supersaturated aqueous solution of borax, the pentahydrate, Na2B407.5H20, is deposited when evaporation takes place at somewhat high temperatures.
m., and is covered by a saline efflorescence; successive crops are obtained by the action of rain and snow and subsequent evaporation.
The deposits formed by evaporation from these lakes and marshes or salines, are mixtures of borates, various alkaline salts (sodium carbonate, sulphate, chloride), gypsum, &c. In the mud of the lakes and in the surrounding marshy soil fine isolated crystals of borax are frequently found.
By rapid evaporation of its solution it may be obtained in small prisms. The pentaflhoride SbF 5 results when metantimonic acid is dissolved in hydrofluoric acid, and the solution is evaporated.
The drainage of this extensive district seems to be wholly absorbed by the dry soil of the desert and by evaporation.
Its outlet is through the Lacahahuira river into the Coipasa swamp, and it is estimated that the outflow is much less than the inflow, showing a considerable loss by evaporation and earth absorption.
And of all Arizona it should be said that owing to the extreme dryness of the air, evaporation from moist surfaces is very rapid,' so that the high temperatures here are decidedly less oppressive than much lower temperatures in a humid atmosphere.
From ' At Yuma, Phoenix and Tucson, the records of twenty-six, eighteen and fifteen years respectively show a rate of evaporation 35.2, 12.7, and 7.7 times as great as the mean annual rainfall, which was 2.84 in., 7.06 in.
The opium is collected in March and April, and the crude drug or " chick " is thrown into an earthen vessel and covered with linseed oil to prevent evaporation.
It readily dissolves in ammonia, the solution, on evaporation, yielding rhombic crystals of 2AgC1.3NH 3; it also dissolves in sodium thiosulphate and potassium cyanide solutions.
Silver nitrate, AgNO 3, one of the most important silver salts, is obtained by dissolving the metal in moderately dilute nitric acid; on evaporation it separates in the anhydrous form as colourless triclinic plates.
This area is not constant, as the water is very shallow at the margins, and the relation between supply from precipitation, &c., and loss by evaporation is variable, there being an annual difference in the height of the water of 15-18 in.
The great lake was then gradually reduced by evaporation, leaving only shallow bodies of salt water, of which Great Salt Lake is the largest.
Inasmuch as the streams entering the basin have no outlet to the ocean, their waters disappear by evaporation, either directly from alluvial slopes over which they pass, or from saline lakes occupying depressions between the mountain ranges.
Salt is obtained by solar evaporation chiefly of the waters of Great Salt Lake and other brine found in that vicinity; at Nephi City, Juab county; near Gunnison, Sanpete county; in Sevier and Millard counties, and at Withee Junction in Weber county.
In the vicinity are a number of lakes, the waters of which on evaporation yield large quantities of very pure and fine salt, which is the object of an extensive trade with the countries of Central Africa.
Where in this article the term " evaporation " is used alone, it is to be understood to include absorption by vegetation.
In the eastern counties the rainfall is lower and the evaporation approximately the same as upon the Thames area, so that the percentage of loss.
They show generally that, as the rainfall increases on any given area evaporation increases, but not in the same proportion.
In estimating the evaporation to be deducted from the rainfall for the purpose of determining the flow into a reservoir, it is important to bear in mind that the loss from a constant water surface is nearly one and a half times as great as from the intermittently saturated land surface.
Yield of There were few rainfall statistics, little was known stream of the total loss by evaporation, and still less of its with distribution over the different periods of dry and reservoir.
In conformity with the above-mentioned convention (by which compensation water is determined as a certain fraction of the average flow during the three driest consecutive years) the available supply or flow from a given area is still understood to be the average annual rainfall during those years, less the corresponding evaporation and absorption by vegetation.
Thus in order to determine truly the continuously available discharge of any stream, it is necessary to know not only the mean flow of the stream, as represented by the rainfall less the evaporation, but also the least favourable distribution of that flow throughout any year.
As the loss by evaporation is a deduction lying between a constant figure and a direct proportional to the rainfall, we should err on the safe side in assuming the flow in the second driest year to be increased proportionally to the rainfall, or by the difference between 63 and 87 equal to 24% of the mean of 50 years.
But in determining the capacity of reservoirs intended to yield a supply of water equal to the mean flow of two, three or more years, the error, though on the safe side, caused by assuming the evaporation to be proportional to the rainfall, is too great to be neglected.
The evaporation slightly increases as the rainfall increases, but at nothing like so high a rate.
Having determined this evaporation for the second driest consecutive year and deducted it from the rainfall - which, as above stated, cannot be less than 87% of the mean of 50 years - we may, as shown on fig.
of evaporation and absorption by vegetation as stated in the note on the diagram.
In the same manner it will be found that by means of a reservoir having an available capacity of only 118,000 gallons per acre of the watershed, we may with the same rainfall and evaporation secure a daily supply of 1085 gallons per acre.
during 50 years, subject to evaporation and absorption equal to 14 in.
It is merely a geometrical determination of the conditions necessarily consequent in England, Scotland and Wales, upon a given mean rainfall over many years, upon evaporation and absorption in particular years (both of which he must judge or determine for himself), and upon certain limiting variations of the rainfall, already stated to be the result of numerous records maintained in Great Britain for more than 50 years.
Moreover, it often falls upon sun-heated rocks, thus increasing the evaporation for the time; but gaugings made by the writer in the northern Apennines indicate that this loss is more than compensated by the greater rapidity of the fall and of the consequent flow.
It would conceivably take but a small fraction of the period that has in most cases elapsed since such upheavals occurred for the salt water to be thus displaced by fresh water, and for the condition to be attained as regards saturation with fresh water, in which with few exceptions we now find the porous portions of the earth's crust wherever the rainfall exceeds the evaporation.
A waterlogged soil is impenetrable by air, and owing to the continuous process of evaporation and radiation, its temperature is much below that of drained soil.
Measurements at the Ripon Falls show that 18,000,000,000, or some 13% of this amount, is taken off by the Nile, and when allowance has been made for the annual rise and fall of the lake-level it is apparent that by far the greater part of the water which enters the nyanza is lost by evaporation; in fact, that the amount drawn off by the river plays a comparatively small part in the annual oscillation of the water surface.
None of its streams reaches the sea, but all lose their waters by seepage or evaporation.
Neither is there any advantage gained by mixing this hydrate with sulphur trioxide; for when such a mixture is concentrated by evaporation, sulphur trioxide is vaporized until the same hydrate is left.
Salt used to be largely manufactured in the district by evaporation, but the industry is now extinct.
The west wind drift sends a stream northwards along the west coast of Australia, the West Australia current, the homologue of the Benguela current in the South Atlantic. The principal feature in the circulation in the depths of the Indian Ocean is a slow movement of Antarctic water northwards along the bottom to take the place of that removed from the surface by evaporation, and by currents in the lower latitudes.
Both rock salt and white salt obtained by evaporation from brine are exported.
The formation of murexide is used as a test for the presence of uric acid, which on evaporation with dilute nitric acid gives alloxantin, and by the addition of ammonia to the residue the purple red colour of murexide becomes apparent.
The Baltic receives much more water by rainfall, discharge of rivers, &c., than it loses by evaporation; hence a surplus must be got rid of by an outflowing current which may be named the "Baltic Stream."
The solution is best prepared by dissolving the hydrate in hydrochloric acid and removing the excess of acid by evaporation, or by passing chlorine into the solution obtained by dissolving the metal in hydrochloric acid and removing the excess of chlorine by a current of carbon dioxide.
By evaporation the green vitriol is obtained as large crystals.
This doubtless prevented evaporation, and retarded vital processes dependent upon oxidation.
The solution of arsenious oxide in water reacts acid towards litmus and contains tribasic arsenious acid, although on evaporation of the solution the trioxide is obtained and not the free acid.
This wind is not invariably hot; its great dryness causes so much evaporation that cold is not infrequently the result.
The water then freezes in virtue of the cold produced by its own evaporation or by the drying of the moistened wrapper.
The highest scientific authority of the day, Major James Rennell, believed, however, that the Niger ended, by evaporation, in the country of "Wangara" - a region located by him, through a misreading of Idrisi, far too much 1 Sir Rufane Donkin in a curious and learned work, A Dissertation on.
Some streams wholly dry up in the dry seasons, and in the foot-hills and sand-hills there are a few that disappear by sinking or evaporation.
By evaporation of its aqueous solution at temperatures above 30° C. it may be obtained in the anhydrous condition.
With the diminishing rainfall and increased temperature that followed that period the effects of evaporation gradually surpassed the precipitation, and the waters of the lake slowly diminished to about the extent which they still display.
The quantity of water poured daily into the sea is not less than 6,000,000 tons, all of which has to be carried off by evaporation.
, P 444) It occurs naturally in very small quantities in zinc blende, and is best obtained from metallic zinc (which contains a small quantity of indium) by treating it with such an amount of hydrochloric acid that a little of the zinc remains undissolved; when on standing for some time the indium is precipitated on the undissolved zinc. The crude product is freed from basic zinc salts, dissolved in nitric acid and the nitric acid removed by evaporation with sulphuric acid, after which it is precipitated by addition of ammonia.
In the first refrigeration is produced by the expansion of atmospheric air, and in the second by the evaporation of a more or less volatile liquid.
Water at ordinary temperature, say 60°, is placed in an air-tight glass or insulated vessel, and when the pressure is reduced by means of a vacuum pump it begins to boil, the heat necessary for evaporation being taken from the water itself.
A vapour compression machine does not, however, work precisely in the reversed Carnot cycle, inasmuch as the fall in temperature between the condenser and the refrigerator is not produced, nor is it attempted to be produced, by the adiabatic expansion of the agent, but results from the evaporation of a portion of the liquid itself.
Evaporation then continues at the constant temperature T, abstracting heat from the substance outside the refrigerator as shown by the line BC. The vapour is then compressed along the line CD to the temperature T2, when, by the action of the cooling water in the condenser, heat is abstracted at constant temperature and the vapour condensed along the line DA.
at atmospheric pressure water will absorb about 760 times its own volume of ammonia vapour), and this produces an evaporation from the liquid in the vessel previously used as a condenser.
In such cases the evaporation of the ammonia or other refrigerating liquid frequently takes place in the cells themselves, brine being dispensed with.
Even under the most advantageous application, that of evaporation of water in a steam boiler where the gases of the fire have to travel through a great length of flues bounded by thin iron surfaces of great heat-absorbing capacity, the temperature of the current at the chimney is generally much above that required to maintain an active draught in the fireplace; and other tubes containing water, often in considerable numbers, forming the so-called fuel economizers, may often be interposed between the boiler and the chimney with marked advantage as regards saving of fuel.
Rock salt is extracted from underground caves by flooding, then evaporation.
evaporite deposits produced by the repeated evaporation of seasonal lakes (see playa ).
We give it from a Goldman halothane vaporizer in series with a halothane vaporizer in series with a halothane vaporizer, using a gauze in the bowl to increase evaporation.
magnetron evaporation techniques during a single coating cycle allows the deposition of multi-layered superlattice coatings.
metastable explosion products decay more slowly by sequential evaporation of light nuclei.
The oceans are the major source of the atmospheric moisture that is obtained through evaporation.
In the full sun they form a three-sided pyramid to prevent excess evaporation.
sebum levels and high moisture evaporation rates.
solvent evaporation and exhaust duct system as standard.
The comparative scantiness of its sources, the steepness of its upper course and the rapid evaporation which takes place after the short rainy season would make the Senegal an insignificant stream for more than half the year; but natural dams cross the channel at intervals and the water accumulates behind them in deep reaches, which thus act as reservoirs.
Cobalt nitrate, Co(NO 3) 2.6H 2 0, is obtained in dark-red monoclinic tables by the slow evaporation of a solution of the metal, its hydroxide or carbonate, in nitric acid.
In the straits joining it with the Atlantic and the Black Sea the fresher surface waters of these seas flow inwards to assist in making good the loss by evaporation at the surface of the Mediterranean, and in both cases dense water makes its way outwards along the bottom of the channels, the outflowing currents being less in volume and delivery than the inflowing.
Nevertheless the secular shrinking goes on, the loss by evaporation and percolation exceeding the amount of water received; whilst, on the average, the rainfall is diminishing.
The midrib bears above a series of closely set, vertical, longitudinally-running plates of green assimilative cells over which the wings close in dry air so as to protect the assimilative and transpiring plates from excessive evaporation of water.
mechanical injury from without, and against the entry of smaller parasites, such as fungi and bacteria, but also and especially to prevent the evaporation of water from within.
the evaporation of water from the leaf goes on from them into the intercellular spaces.
Transpiration.In the case of terrestrial plants, the continual renewal of the water contained in the vacuoles of the protoplasts demands a copious and continuous evaporation.
This large evaporation, which constitutes the so-called transpiration of plants, takes place not into the external air but into this same intercellular space system, being possible only through the delicate cell-walls upon which it abuts, as the external coating, whether bark, cork or cuticle, is impermeable by watery vapour.
In these we have (1) the evaporation from the damp delicate cell-walls into the intercellular spaces; (2) the imbibition by the cell-wall of water from the vacuole; (3) osmotic action, consequent upon the subsequent increased concentration of the cell sap, drawing water from the wood cells or vessels which abut upon the leaf parenchyma.
Few of the mountain creeks succeed in reaching the arid plains, and those that do quickly disappear by evaporation or by seepage into the gravels.
(39Ã‚°); evaporation below these limits is supreme.
After 1900 the production of salt rapidly increased up to 1906, when it was 11,249 bbls.; in 1907 it was only 6457 bbls., all graded as " common coarse " and all obtained by solar evaporation from brine.
Since on an average 70% by measurement of the normal defecated cane juice has to be evaporated in order to reduce it to syrup ready for final concentration and crystallization in the vacuum pan, and since to attain the same end as much as 90 to 95% of the volume of mixed juices has to be evaporated when maceration or imbibition is employed, it is clear that some more economical mode of evaporation is necessary in large estates than the open-fire batteries still common in Barbados and some of the West Indian islands, and in small haciendas in Central America and Brazil, but seldom seen elsewhere.
The shaft Crystal- carries arms and blades fixed in such a manner that the mass of sugar is quietly but thoroughly moved, while at the same time a gentle but sustained evaporation is produced by the continuous exposure of successive portions of the mass to the action of the atmosphere.
The tube is tightly corked to prevent evaporation, and allowed to stand for some hours.
Apart from the effects of varying precipitation and evaporation the atmosphere affects sea-level also by its varying pressure, the difference in level of the sea-surface from this cause between two given points being thirteen times as great as the difference between the corresponding readings of the mercurial barometer.
The origin of the salt of the sea is attributed by some modern authorities entirely to the washing out of salts from the land by rain and rivers and the gradual concentration by evaporation in the oceans, and some (e.g.
Morthoe, Luton Hoo, the Hoe at Plymouth, &c.; this is the same as Northern English "heugh" and is connected with "hang"), an agricultural and gardening implement used for extirpating weeds, for stirring the surface-soil in order to break the capillary channels and so prevent the evaporation of moisture, for singling out turnips and other root-crops and similar purposes.
The liquid boils at - 78.2Ã‚° C. (1 atmo.), and by rapid evaporation can be made to solidify to a snow-white solid which melts at - 65Ã‚° C. (see Liquid Gases).
It is here that an irrigation project, involving the diversion of some of the river water to the low plain, led to disaster in 1904, when the flooded river washed away the canal gates at the intake and overflowed the plain, drowning the newly established farms, compelling a railway to shift its track, and forming a lake (Salton Sea) which would require years of evaporation to remove (see COLORADO RIvER).
The benzene layer on evaporation deposits the antipyrine as a colourless crystalline solid which melts at 113Ã‚° C. and is soluble in water.
cacti, euphorbias, &c.) from hot, dry and almost waterless regions where evaporation would be excessive, the leaf surface, and consequently the number of stomata, are reduced to a minimum, as it would be fatal to such plants to exhale vapour as freely in those regions as the broad-leaved plants that grow in places where there is abundance of moisture.
Wdhler oxidized potassium ferrocyanide to potassium cyanate by fusing it with lead or manganese dioxide, converted this cyanate into ammonium cyanate by adding ammonium sulphate, and this on evaporation gives urea, thus: K 4 Fe(NC)r-->K CNO--->NH4CNO->CO (NH2)2 It may also be prepared by the action of ammonia on carbonyl chloride, diethyl carbonate, chlorcarbonic ester or urethane; by heating ammonium carbamate in a sealed tube to 130-140Ã‚° C.; by oxidizing potassium cyanide in acid solution with potassium permanganate (E.
2H 2 O, by concentrating the solution between 15Ã‚° C. and 20Ã‚°C.; the other, isomorphous with FeCl 2.4H 2 0, by slow evaporation of the mother liquors from the former.
The Rapid Rise From 25Ã‚° To 75Ã‚° May Be Due To Radiation Error From The Hot Water Supply, And The Subsequent Fall Of The Curve To The Inevitable Loss Of Heat By Evaporation Of The Boiling Water On Its Way To The Calorimeter.
The Peculiar Advantage Of The Electric Method Of Callendar And Barnes, Already Referred To, Is That The Specific Heat Itself Is Determined Over A Range Of 8Ã‚° To 10Ã‚° At Each Point, By Adding Accurately Measured Quantities Of Heat To The Water At The Desired Temperature In An Isothermal Enclosure, Under Perfectly Steady Conditions, Without Any Possibility Of Evaporation Or Loss Of Heat In Transference.
Evaporation of the aqueous solution at 15Ã‚° C. deposits a crystalline hydrated hydroxide of composition RbOH 2H 2 O (R.
On heating, it begins to decompose at 260-265Ã‚° C. Barium chlorate, Ba(C103)2, is obtained by adding barium chloride to sodium chlorate solution; on concentration of the solution sodium chloride separates first, and then on further evaporation barium chlorate crystallizes out and can be purified by recrystallization.
The filtrate or opium solution is concentrated by evaporation at the boiling point, with occasional stirring until of a proper consistence, the time required being from three to four hours; it is then removed from the fire and stirred with great vigour till cold, the cooling being accelerated by coolies with large fans.
Gazette, xlvi., 1908, regards this tissue as belonging to the nucellus.) At the time of pollination the long tubular integument secretes a drop of fluid at its apex, which holds the pollen-grains, brought by the wind, or possibly to some extent by insect agency, and by evaporation these are drawn on to the top of the nucellus, where partial disorganization of the cells has given rise to an irregular pollen-chamber (fig.
By evaporation of its aqueous solution at temperatures above 30Ã‚° C. it may be obtained in the anhydrous condition.
The consequence of the ancient evaporation, by which the great Pleistocene lake was reduced to its present modest dimensions, and of the ceaseless modern daily evaporation, is the impregnation of the waters of the lake with salts and other mineral substances to a remarkable degree.
The mists, due to the great heat and excessive evaporation, and the noxious miasmata, especially of the southern region, were exaggerated into the noisome vapours that the "black and stinking" waters ever exhaled.
Water at ordinary temperature, say 60Ã‚°, is placed in an air-tight glass or insulated vessel, and when the pressure is reduced by means of a vacuum pump it begins to boil, the heat necessary for evaporation being taken from the water itself.
Though prior to 1834 several suggestions had been made with regard to the production of ice and the cooling of liquids by the evaporation of a more volatile liquid than water, the first machine actually constructed and put to work was made by John Hague in that year from the designs of Jacob Perkins (Journal of Soc. of Arts, 1882, vol.
Fume Exhaust System RDM Ovens incorporate a powerful and positive, fan assisted, fume and solvent evaporation and exhaust duct system as standard.
Second is evaporation of moisture which adds flavor because as moisture decreases and the beef shrinks, flavor intensifies.
Wet-aged beef isn't exposed to air so it doesn't lose as much moisture through evaporation.
Just be careful to watch the water level of your crockpot as the heat will cause evaporation.
Mulch - Mulch will slow down the evaporation of moisture from the soil.
Warmer temperatures will also increase evaporation from large water bodies, which in turn will increase cloud formation and rainfall amounts.
In other areas of the world, increased temperature in the summer and fall increases the evaporation rate and means more droughts and wildfires.
As temperatures rise, evaporation from land increases, sending more moisture into the air.
In the 1920s, William Poucher began to measure the evaporation rates of various oils used in perfumes.
I was pleased that I could wear Cover Girl's eyeliner on the inside rim of the eye without it running and without the color evaporation.
One Drop Perfume is an oil-based fragrance concept manufactured by Egyptian Potion that promises long wear without the evaporation that occurs in alcohol-based essences.
The plants thrive best in moist districts, and in dry ones evaporation may be prevented by covering the ground near them with cocoa-fibre mixed with sand.
All mulches help to retain water near the plant's roots where it's needed, but wood mulch is said to allow more evaporation than rubber mulch.
A thick layer of mulch helps retain water and prevents evaporation.
The mulch helps keep the water in the ground preventing evaporation around the plants.
I suppose the players are supposed to be quite hot and it's simply the evaporation that is causing this glow, but I didn't like it.
The paper is then covered with wax or a sheet of plastic, so that evaporation does not occur.
The evaporation of moisture on the skin also produces cooling.
Evaporation occurs when the sun heats water in lakes or oceans and turns it into steam.
The University of Richmond website provides a list of interesting facts about the water cycle and an animated illustration to teach children about precipitation, evaporation, condensation, and saturation.
A common cause of a false positive result is waiting too long to read the test results, since early pregnancy tests may display an evaporation line outside of the five minute test reaction time.
If you've ever taken a home pregnancy test, you may wonder what an evaporation line on a pregnancy test means.
An evaporation line can show up as a faint line on a pregnancy test.
Evaporation lines usually show up as a shadowy line.
After this time frame is up, you may get inaccurate results due to an evaporation line on a pregnancy test.
You're looking at an evaporation line: It's important to follow the directions that come with any pregnancy test you take.
It's not uncommon for an evaporation line to show up several minutes after accurate test results are reported.
Evaporation lines are usually colorless--they don't show up pink or blue as a real test result would.
To avoid reading evaporation lines, read the results of your test within the recommended time frame.
Another type of portable air conditioner uses a water reservoir to cool the air through evaporation.
Armour HeatGear technology helps to reduce sweatiness inside the shoe and speed up evaporation of moisture.
Evaporation becomes accelerated when the shoes draw moisture away from the feet and towards the outer layer.
Rapid evaporation: When you're playing outside for hours at a time, especially on warm days, you don't want to end up with sweaty feet.
While most paints dry by evaporation, oil paint dries through oxidation.
Oil paint dries through oxidation, not evaporation.
It slows down evaporation of water to guard against dehydration.
Lavoisier he made an important series of experiments on specific heat (1782-1784), in the course of which the "ice calorimeter" was invented; and they contributed jointly to the Memoirs of the Academy (1781) a paper on the development of electricity by evaporation.
The solution in sulphuric acid deposits green crystals of the sulphate, U(S04)2.8H20, on evaporation.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.