# Density sentence example

density

- One half of the earth has therefore a greater density than the other.
- One of the most remarkable of Airy's researches was his determination of the mean density of the earth.
- The density of helium has been determined by Ramsay and Travers as 1.98.
- The density of population increased from 16.5 per sq.
- The density of solid sulphur is 2 062 to 2'070, and the specific heat 0.1712; it is a bad conductor of electricity and becomes negatively electrified on friction.Advertisement
- It fuses at 415° C. and under ordinary atmospheric pressure boils at 1040° C. Its vapour density shows that it is monatomic. The molten metal on cooling deposits crystals belonging to the hexagonal system, and freezes into a compact crystalline solid, which may be brittle or ductile according to circumstances.
- Gravitation Constant And Mean Density Of The Earth >>
- The above theory, coupled with such facts as the variation of the composition of the constant boiling-point fraction with the pressure under which the mixture is distilled, the proportionality of the density of all mixtures to their composition, &c., shows this to be erroneous.
- Everything is air at different degrees of density, and under the influence of heat, which expands, and of cold, which contracts its volume, it gives rise to the several phases of existence.
- Of these 71,512 were in Coburg and 170,920 in Gotha; the relative density in either duchy being about equal.Advertisement
- living in communities of less than 2000 inhabitants; while the density of the population is about 330 to the square mile.
- and reported on Nevil Maskelyne's determination of the mean density and mass of the earth from measurements taken in 1774-1776 at Mount Schiehallion in Perthshire.
- By the surface density of electrification on a conductor is meant the charge per unit of area, or the number of tubes of electric force which spring from unit area of its surface.
- Coulomb proved experimentally that the electric force just outside a conductor at any point is proportional to the electric density at that point.
- equal to 47ro-, where ois the surface density at that point.Advertisement
- The electric density on the sphere being uniform, the quantities of electricity on these areas are proportional to the areas, and if the electric force varies inversely as the square of the distance, the forces exerted by these two surface charges at the point in question are proportional to the solid angle of the little cone.
- Since the potential of a small charge of electricity dQ at a distance r is equal to dQ/r, and since the potential of all parts of a conductor is the same in those cases in which the distribution of surface density of electrification is uniform or symmetrical with respect to some point or axis in the conductor, we can calculate the potential by simply summing up terms like rdS/r, where dS is an element of surface, o- the surface density of electricity on it, and r the distance from the symmetrical centre.
- Thus if Q is the surface density, S the thickness of the shell at any point, and p the assumed volume density of the matter of the shell, we have v =Abp. Then the quantity of electricity on any element of surface dS is A times the mass of the corresponding element of the shell; and if Q is the whole quantity of electricity on the ellipsoid, Q =A times the whole mass of the shell.
- Accordingly for a given ellipsoid the surface density of free distribution of electricity on it is everywhere proportional to the the tangent e plane e att that point.
- If we consider a length l of the cylinder, the charge Q on the inner cylinder is Q=27rR l ly, where v is the surface density, and by Coulomb's law v = E i /47r, where E 1 = A/R 1 is the force at the surface of the inner Ai cylinder.Advertisement
- But if v is the surface density, E=47rv, and a=Q/S.
- Let this rectangular prism be supposed to be wholly filled up with electricity of density p; then the total quantity in it is p dx dy dz.
- We can, however, obtain another equation called the " surface characteristic equation " as follows: - Suppose a very small area dS described on a conductor having a surface density of electrification a.
- In the next place apply the surface characteristic equation to any point on a charged conductor at which the surface density is a.
- The above is a statement of Coulomb's law, that the electric fores at the surface of a conductor is proportional to the surface density of the charge at that point and equal to 41r times the density.3 See Maxwell, Electricity and Magnetism, vol.Advertisement
- Every tube of electric force must therefore begin and end on electrified surfaces of opposite sign, and the quantities of positive and negative electricity on its two ends are equal, since the force E just outside an electrified surface is normal to it and equal to a/41r, where a is the surface density; and since we have just proved that for the ends of a tube of force EdS = E 1 dS', it follows that adS = a'dS', or Q = Q', where Q and Q' are the quantities of electricity on the ends of the tube of force.
- If a is the surface density and dS an element of surface, then fadS is the whole charge, and hence afV adS is the expression for the energy of charge of a conductor.
- The first term on the right hand side expresses the energy of the surface electrification of the conductors in the field, and the second the energy of volume density (if any).
- If we make a distribution of negative electricity over it, which has a density a varying according to the law a = -(d 2 -r 2) q /42rr AP3.
- which is useful for calculating the variation of the specific heat s with variation of density at constant temperature.Advertisement
- The specific heats are independent of the pressure or density by equations (to) and (12).
- p. 211, Paris, 1869) proposed an equation of the form (p+po)(v - b) =RO, in which the effect of the size of the molecules is represented by subtracting a quantity b, the " covolume," from the volume occupied by the gas, and the effect of the mutual attractions of the molecules is represented by adding a quantity po, the internal pressure, to the external pressure, p. This type of equation, was more fully worked out by van der Waals, who identified the internal pressure, po, with the capillary pressure of Laplace, and assumed that it varied directly as the square of the density, and could be written a/v 2 .
- v, Specific volume of fluid, reciprocal of density.
- The specific gravity of cast gold varies from 18.29 to 19.37, and by compression between dies the specific gravity may be raised from 19.37 to 19.41; by annealing, however, the previous density is to some extent recovered, as it is then found to be 19.40.
- In the alluvial deposits the associated minerals are chiefly those of great density and hardness, such as platinum, osmiridium and other metals of the platinum group, tinstone, chromic, magnetic and brown iron ores, diamond, ruby and sapphire, zircon, topaz, garnet, &c. which represent the more durable original constituents of the rocks whose distintegration has furnished the detritus.Advertisement
- Matthiessen observed that the density of alloys, the composition of which varies from AuAg 6 to Au 6 Ag, is greater than that calculated from the densities of the constituent metals.
- The alloys of tin and gold are hard and brittle, and the combination of the metals is attended with contraction; thus the alloy SnAu has a density 14.243, instead of 14.828 indicated by calculation.
- In these proportions the density of the alloy is less than the mean of its constituent metals.
- One process depends upon the fact that, with a suitable current density, if a very dilute solution of silver nitrate be electrolysed between an auriferous silver anode and a silver cathode, the silver of the anode is dissolved out and deposited at the cathode, the gold remaining at the anode.
- Among these were the exponential calculus, and the curve called by him the linea brachistochrona, or line of swiftest descent, which he was the first to determine, pointing out at the same time the relation which this curve bears to the path described by a ray of light passing through strata of variable density.Advertisement
- The important part played by the residual air in the globe had also been deduced by Osborne Reynolds from observing that on turning off the light, the vanes came to rest very much sooner than the friction of the pivot alone would account for; in fact, the rapid subsidence is an illustration of Maxwell's great theoretical discovery that viscosity in a gas (as also diffusion both of heat and of the gas itself) is sensibly independent of the density.
- In air of considerable density the mean free path of a molecule, between its collisions with other molecules, is exceedingly small, and any such increase of gaseous pressure in front of the black surface would be immediately neutralized by flow of the gas from places of high to places of low pressure.
- well-educated; and, owing to the uniformly high birth-rate, low death-rate, and very slight loss by emigration, their numbers increased rapidly during the latter part of the 19th century, until in 1900 the density of population (372.4 per sq.
- DENSITY (Lat.
- densus, thick), in physics, the mass or quantity of matter contained in unit volume of any substance: this is the absolute density; the term relative density or specific gravity denotes the ratio of the mass of a certain volume of a substance to the mass of the same volume of some standard substance.Advertisement
- Other standards of reference may be used in special connexions; for example, the Earth is the usual unit for expressing the relative density of the other members of the solar system.
- Reference should be made to the article Gravitation for an account of the methods employed to determine the "mean density of the earth."
- In expressing the absolute or relative density of any substance, it is necessary to specify the conditions for which the relation holds: in the case of gases, the temperature and pressure of the experimental gas (and of the standard, in the case of relative density); and in the case of solids and liquids, the temperature.
- The reason for this is readily seen; if a mass M of any gas occupies a volume V at a temperature T (on the absolute scale) and a pressure P, then its absolute density under these conditions is O = M/V; if now the temperature and pressure be changed to l and P,, the volume V l under these conditions is VPT/PIT1, and the absolute density is MP,T/VPT I.
- The density gives very important information as to the molecular weight, since by the law of Avogadro it is seen that the relative density is the ratio of the molecular weights of the experimental and standard gases.Advertisement
- It may be noted that if comparison be made with water at 4°, the relative density is the same as the absolute density, since the unit of mass in the C.G.S.
- Thus if d be the relative density, then Iod represents the weight of a gallon in lb.
- Calling the weight of the empty vessel w, when filled with the liquid W, and when filled with the standard substance W l, it is obvious that W - w, and W1 - w, are the weights of equal volumes of the liquid and standard, and hence the relative density is (W - w)/(Wi - w).
- The specific gravity bottle may be used to determine the relative density of a solid which is available in small fragments, and is insoluble in the standard liquid.
- It is readily seen that W+W i - W 2 is the weight of the liquid displaced by the solid, and therefore is the weight of an equal volume of liquid; hence the relative density is W/(W+Wi - W2).
- Related to the determination of the density of a gas is the determination of the density of a vapour, i.e.
- This subject owes its importance in modern chemistry to the fact that the vapour density, when hydrogen is taken as the standard, gives perfectly definite information as to the molecular condition of the compound, since twice the vapour density equals the molecular weight of the compound.
- The vapour density is calculated by the following formula: D - W(1 +at) X587,780 (p-s) V in which W =weight of substance taken, V =volume of air expelled, a= 1/273 = .003665, t and p = temperature and pressure at which expelled air is measured, and s= vapour pressure of water at 1°.
- For higher temperatures the bulb of the vapour density tube is made of porcelain or platinum, and is heated in a gas furnace.
- Hydro- statical principles can be applied to density determinations in four typical ways: (I) depending upon the fact that the heights of liquid columns supported by the same pressure vary inversely as the densities of the liquids; (2) depending upon the fact that a body which sinks in a liquid loses a weight equal to the weight of liquid which it displaces; (3) depending on the fact that a body remains suspended, neither floating nor sinking, in a liquid of exactly the same density; (4) depending on the fact that a floating body is immersed to such an extent that the weight of the fluid displaced equals the weight of the body.
- Hence W/(W - W,) is the relative density or specific gravity of the body.
- The principle is readily adapted to the determination of the relative densities of two liquids, for it is obvious that if W be the weight of a solid body in air, W, and W2 its weights when immersed in the liquids, then W - W, and W - W 2 are the weights of equal volumes of the liquids, and therefore the relative density is the quotient (W - W,)/(W - W2).
- If W be the weight of the experimental solid in air, w the weight of the sinker in water, and W, the weight of the solid plus sinker in water, then the relative density is given by W/(W+w - Wi).
- There are several corrections of the formula O =W/(W - W1) necessary to the accurate expression of the density.
- Similarly in the case of the weighing in water, account must be taken of the buoyancy of the weights, and also, if absolute densities be required, of the density of water at the temperature of the experiment.
- In a form of great accuracy the absolute density 0(0°/4°) is given by (0 °/4°) = (PaW - SW,)/(W - W,), in which W is the weight of the body in air at t° and p mm.
- pressure, W i the weight in water, atmospheric conditions remaining very nearly the same; p is the density of the water in which the body is weighed, a is (I +at°) in which a is the coefficient of cubical expansion of the body, and S is the density of the air at t°, p mm.
- Less accurate formulae are =p W/(W - W 2), the factor involving the density of the air, and the coefficient of the expansion of the solid being disregarded, and 0 =W/(W - W 1), in which the density of water is taken as unity.
- To determine the density of any liquid it is only necessary to suspend the plummet in the liquid, and to bring the beam to its normal position by means of the riders; the relative density is read off directly from the riders.
- Methods depending on the free suspension of the solid in a liquid of the same density have been especially studied by Retgers and Gossner in view of their applicability to density determinations of crystals.
- Two typical forms are in use; in one a liquid is prepared in which the crystal freely swims, the density of the liquid being ascertained by the pycnometer or other methods; in the other a liquid of variable density, the so-called "diffusion column," is prepared, and observation is made of the level at which the particle comes to rest.
- Acetylene tetrabromide, C 2 H 2 Br 4, which is very conveniently prepared by passing acetylene into cooled bromine, has a density of 3 ooi at 6° C. It is highly convenient, since it is colourless, odourless, very stable and easily mobile.
- Methylene iodide, CH 2 I 2, has a density of 3.33, and may be diluted with benzene.
- Its advantages rest on its high density and mobility; its main disadvantages are its liability to decomposition, the originally colourless liquid becoming dark owing to the separation of iodine, and its high coefficient of expansion.
- Its density may be raised to 3.65 by dissolving iodoform and iodine in it.
- Goldschmidt, has a density of 3.196 at 22.9°.
- rend., 1905, p. 141) has investigated the solutions of mercuric iodide in other alkaline iodides; sodium iodo-mercurate solution has a density of 3.46 at 26°, and gives with an excess of water a dense precipitate of mercuric iodide, which dissolves without decomposition in alcohol; lithium iodo-mercurate solution has a density of 3.28 at 25.6°; and ammonium iodo-mercurate solution a density of 2.98 at 26°.
- Rohrbach's solution, an aqueous solution of barium and mercuric iodides, introduced by Carl Rohrbach, has a density of 3.588.
- Klein, has a density up to 3.28.
- The salt melts in its water of crystallization at 75°, and the liquid thus obtained goes up to a density of 3.6.
- Silver-thallium nitrate, TIAg(N03)2, introduced by Retgers, melts at 75° to form a clear liquid of density 4.8; it may be diluted with water.
- In the "diffusion column" method, a liquid column uniformly varying in density from about 3.3 to I is prepared by pouring a little methylene iodide into a long test tube and adding five times as much benzene.
- The density of the column at any level is determined by means of the areometrical beads proposed by Alexander Wilson (1714-1786), professor of astronomy at Glasgow University.
- These are hollow glass beads of variable density; they may be prepared by melting off pieces of very thin capillary tubing, and determining the density in each case by the method just previously described.
- By successive trials two beads, of known density, say di, d 2, are obtained, one of which floats above, and the other below, the test crystal; the distances separating the beads from the crystal are determined by means of a scale placed behind the tube.
- If the bead of density dl be at the distance l l above the crystal, and that of d 2 at l 2 below, it is obvious that if the density of the column varies uniformly, then the density of the test crystal is (d1l2-+d211)/(ll+l2).
- Acting on a principle quite different from any previously discussed is the capillary hydrometer or staktometer of Brewster, which is based upon the difference in the surface tension and density of pure water, and of mixtures of alcohol and water in varying proportions.
- Hence any impurity which diminishes the surface tension of the water will diminish the size of the drop (unless the density is proportionately diminished).
- - Density and density determinationsare discussed in all works on practical physics; reference may be made to B.
- The density of gases is treated in M.
- Travers, The Experimental Study of Gases (1901); and vapour density determinations in Lassar-Cohn's Arbeitsmethoden fur organisch-chemische Laboratorien (1901), and Manual of Organic Chemistry (1896), and in H.
- If the whole globe were covered with a uniformly deep ocean, and if there were no difference of density between one part and another, the surface would form a perfect ellipsoid of revolution, that is to say, all the meridians would be exactly equal ellipses and all parallels perfect circles.
- But as things are the watersurface is broken by land, and the mean density of the substance of the land is 2 6 times as great as that of sea-water, so that the gravitational attraction of the land must necessarily cause a heaping up of the sea around the coasts, forming what has been called the continental wave, and leaving the sea-level lower in mid-ocean.
- compared with pure water at the maximum density point (39.2°) as unity.
- The temperature of maximum density of sea-water of any specific gravity was found by Knudsen to be given with sufficient accuracy for all practical purposes by the formula 0 = 3.950.2660 -0, where 0 is the temperature of maximum density in degrees centigrade.
- The temperature of maximum density is lower as the concentration of the sea-water is greater, as is shown in the following table: Maximum Density Point of Sea-Water of Dif f erent Salinities.
- The compressibility is in itself very small, but so great in its effect on the density of deep water in situ that the specific gravity (0 0 /4°) at 2000 fathoms increases by o 017 and at 3000 fathoms by o 026.
- The difference in density which occurs between one part of the ocean and another, shares with the wind in the production of currents.
- Strongly marked differences in density are produced by the melting of sea-ice, and this is of particular importance in the case of the great ice barrier round the Antarctic continent.
- Pettersson has made a careful study of ice melting as a motive power in oceanic circulation, and points out that it acts in two ways: on the surface it produces dilution of the water, forming a fresh layer and causing an outflow seaward of surface water with very low salinity; towards the deep water it produces a strong cooling effect, leading to increase of density and sinking of the chilled layers.
- 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.
- Wind and tide greatly alter the strength of these currents due to difference of density, and the surface outflow may either be stopped or, in the case of the belts, actually reversed by a strong and steady wind.
- As a rule, the density increases with the amount of carbon, but in some instances a very high specific gravity is due to intermixed earthy matters, which are always denser than even the densest form of coal substance.
- It is a colourless gas, having a density of 0.92.
- For instance, in practical working it has been found that a furnace return of oï¿½ 504 lb per kilowatt hour is brought down to 0.406 lb per kilowatt hour when the material has been broken up, sorted and packed in air-tight drums. In the tapping process a fixed crucible is used, lined with carbon, the electrode is nearly as big as the crucible and a much higher current density is used.
- Calcium carbide, as formed in the electric furnace, is a beautiful crystalline semi-metallic solid, having a density of 2.22, and showing a fracture which is often shot with iridescent "non-automatic."
- At normal temperature and pressure the density of a substance in the gaseous state is of the order of one-thousandth of the density of the same substance in the solid or liquid state.
- If p is the density corresponding to pressure p, we find that,}, formula (Ii) assumes the form P = 3PC2, where C is a velocity such that the gas would have its actual translational energy if each molecule moved with the same velocity C. By substituting experimentally determined pairs of values of p and p we can calculate C for different gases, and so obtain a knowledge of the magnitudes of the molecular velocities.
- - The laws which have just been stated are obeyed very approximately, but not with perfect accuracy, by all gases of which the density is not too great or the temperature too low.
- It had a population of 88,744 in .1901, showing an increase of 20% in the decade and giving a density of 9 inhabitants to the sq.
- m., or about half the size of Cambridgeshire in England, and the united population in 1905 was 59,127, showing a density of 138 to the square mile.
- An unusual density of urban settlement, furnishing excellent home markets and transportation facilities, are the main props of this new interest.
- The elements of this disparate pair, calculated by Dr Vogel on the somewhat precarious assumption that its dark and bright members are of equal mean density, are as follows: Diameter of Algol.
- Mean density.
- Other parts of the state, where connected with the main highway, are influenced by it to some extent; but away from the great natural route of commerce New York is not especially noteworthy either for it, density of population or for extensive manufacturing and commerce.
- The population in 1905 was 1,641,746, showing a mean density of 166 to the sq.
- U cubic centimetres move in per second at B, and if the density is po the mass moving in through a square centimetre is po U.
- If y is the displacement at A, and if E is the elasticity, substituting for w and u from (2) and (3) we get X - Ed x d +pU2 But since the volume dx with density po has become volume dx+dy with density p p (d = po.
- cm., the density of dry air at o° C. being taken as 0.001293, we get for the velocity in dry air at o° C.
- The kinetic energy per cubic centimetre is 2 pu t, where is the density and u is the velocity of disturbance due to the passage of the wave.
- When a wave of sound travelling through one medium meets a second medium of a different kind, the vibrations of its own particles are communicated to the particles of the new medium, so that a wave is excited in the latter, and is propagated through it with a velocity dependent on the density and elasticity of the second medium, and therefore differing in general from the previous velocity.
- (20) We have already found the energy density in the train and the energy stream in equations (13) and (14).
- If U is the velocity of sound in a gas at pressure P with density p, and if waves of length X and frequency N are propagated through it, then the distanc?e l between the dust-heaps is 2 = N - zN Vyp' where y is the ratio of the two specific heats.
- Both obtained the value for the velocity (U I C RA(21rNp ' where U is the velocity in free air, R is the radius of the pipe, N the frequency, and p the air density.
- At B there is only the latter kind, and since the transfer of matter is powoU, where po is the undisturbed density and wo is the undisturbed cross-section, since its velocity is U the passage of momentum per second is powoUo 2.
- If p is the density at A, and w the cross-section, then the momentum carried past A is pc,(U - u) 2.
- Also since dx has been stretched to +dy p&,(dx +dy) =po&odx or p&'(I +dy/dx) = (29) Substituting from (28) in (27) Y&a + P(2)U 2 (I + dy (3) 2 = p oc?oU 2, 0) and substituting from (29) in (30) Y&ao dx + pocZoU 2 + dx) = p owoU 2, (31) whence Yc = powoU2, or U2 = Y/ p, (32) where now p is the normal density of the rod.
- The mass of matter moving through A per second is pwa 2 U, where a is the radius of the wire and p is its density.
- Substituting in (33) we get U 2 = n/p. (34) If we now keep the wire at rest the disturbance travels along it with velocity U= d (nip), and it depends on the rigidity and density of the wire and not upon its radius.
- SAXONY, a kingdom of Germany, ranking among the constituent states of the empire, fifth in area, third in population and first in density of population, bounded on the S.
- Soc., 1889, 55, p. 163) determined the vapour density of hydrofluoric acid at different temperatures, and showed that there is no approach to a definite value below about 88° C. where it reaches the value 10.29 corresponding to the molecular formula HF; at temperatures below 88° C. the value increases rapidly, showing that the molecule is more complex in its structure.
- Let E be the effective elasticity of the aether; then E = pc t, where p is its density, and c the velocity of light which is 3 X 10 10 cm./sec. If = A cos" (t - x/c) is the linear vibration, the stress is E dE/dx; and the total energy, which is twice the kinetic energy Zp(d/dt) 2 dx, is 2pn2A2 per cm., which is thus equal to 1.8 ergs as above.
- It follows that the density of the aether must exceed io 18, and its elastic modulus must exceed Io 3, which is only about io s of the modulus of rigidity of glass.
- The most fundamental experimental confirmation that the theory of the aether has received on the optical side in recent years has been the verification of Maxwell's proposition that radiation exerts mechanical force on a material system, on which it falls, which may be represented in all cases as the resultant of pressures operating along the rays, and of intensity equal at each point of free space to the density of radiant energy.
- In respect of population it occupies the tenth place among European countries; in respect of size the fourteenth place; in density of population the seventh.
- In 1772 he suggested to the Royal Society the famous Schehallion experiment for the determination of the earth's density and carried out his plan in 1774 (Phil.
- From Maskelyne's observations Charles Hutton deduced a density for the earth 4.5 times that of water (ib.
- These values of p refer to a standard density of the air, of 534.22 grains per cubic foot, which is the density of dry air at sea-level in the latitude of Greenwich, at a temperature of 62° F.
- But in consequence of the humidity of the climate of England it is better to suppose the air to be (on the average) two-thirds saturated with aqueous vapour, and then the standard temperature will be reduced to 60° F., so as to secure the same standard density; the density of the air being reduced perceptibly by the presence of the aqueous vapour.
- It is further assumed, as the result of experiment, that the resistance is proportional to the density of the air; so that if the standard density changes from unity to any other relative density denoted by then R= Td 2 p, and is called the coefficient of tenuity.
- Starting with the experimental values of p, for a standard projectile, fired under standard conditions in air of standard density, we proceed to the construction of the ballistic table.
- As a preliminary step to the determination of the pressure in the bore of a gun, it is desirable to measure the pressure obtained by exploding a charge of powder in a closed vessel, varying the weight of the charge and thereby the density of the powder-gas.
- 8 and 9, in a curve showing the relation between p and D the gravimetric density, which is the specific gravity of the P lb of powder when filling the volume C, cub.
- -70.75 80 Gravimetric Density Of Products Of Explosion Fig.
- Sometimes the factor 27.68 is employed, corresponding to a density of water of about 62-4 lb per cub.
- Charge: weight 13 lb 4 oz.; gravimetric density 55.01/0.504; nature, cordite, size 30.
- The experimental determination of the time of burning under the influence of the varying pressure and density, and the size of the grain, is thus of great practical importance, as thereby it is possible to estimate close limits to the maximum pressure that will be reached in the bore of a gun, and to design the chamber so that the G.D.
- This fact, coupled with the determination of the vapour density of the gas, establishes the molecular formula CO.
- Its Vapour Density Is 2.1046 (Air= I).
- It forms colourless cubes which are readily soluble in water, melt at 685°, and yield a vapour of normal density.
- m., the third in density in Spain.
- (a) The unit of volume for determinations of a high degree of accuracy is the volume occupied by the mass of 1 kilogram of pure water at its maximum density and under the normal atmospheric pressure; this volume is called litre.
- (at 32° F.), is equal to 252.207 grains weight of water at its maximum density (4° C.).
- There appears, however, to be some objection to the use of iridio-platinum for weights, as, owing to its great density (Î”=21.57), the slightest abrasion will make an appreciable difference in a weight; sometimes, therefore, quartz or rock-crystal is used; but to this also there is some objection, as owing to its low density (Î”=2.65) there is a large exposed surface of the mass.
- Ï, the density (0.001218738) of dry air, containing 4 vols.
- d is the density of water at 62° F.
- dl, the density of the brass as above.
- Owing to the great pressure on the soil from the density of the population, to the reluctance to part with land characteristic of small proprietors, to the generally great productiveness of land and to the very light assessment of government revenue, land in Ballia, for agricultural purposes merely, has a market value higher than in almost any other district.
- Asplanchnaceae, plankton, dwellers in small pools, are, however, ovoid, and Trochosphaera is spherical and must owe its floating powers to the low density of the liquid in its enormously dilated bodycavity.
- The sodium vapour in the middle is very dense on the heated side, the density diminishing rapidly towards the upper part of the tube, so that, although not prismatic in form, it refracts like a prism owing to the variation in density.
- Meyer (Be y ., 1880, 1 3, p. 394), who found that the change of colour was accompanied by a change of vapour density.
- Thus, the density of air being taken as unity, Victor Meyer found the following values for the density of iodine vapour at different temperatures: T° C...
- In the eastern forest region the number of species decreases somewhat from south to north, but the entire region differs from the densely forested region of the Pacific Coast Transition zone in that it is essentially a region of deciduous or hardwood forests, while the latter is essentially one of coniferous trees; it differs from the forested region of the Rocky Mountains in that the latter is not only essentially a region of coniferous trees, but one where the forests do not by any means occupy the whole area, neither do they approach in density or economic importance those of the eastern division of the country.
- Total area covered by Density of population.
- Ten states of the Union had a density in 1910 exceeding 100 persons to the square mile: Illinois (100.7), Delaware (103), Ohio (117), Maryland (130.3), Pennsylvania (171.3), New York (191.2), Connecticut (231.3), NewJersey (~3i~~3), Massachusetts (418.8) and Rhode Island (508.5).
- On the westward slopes, especially of the Selkirks and Coast Ranges, vegetation is almost tropical in its density and luxuriance, the giant cedar and the Douglas fir sometimes having diameters of 10 ft.
- The density of population is greatest in Prince Edward Island, where it is 51.6 to the sq.
- This is not an indication of the density in settled parts; as in Quebec, Ontario and the western provinces there are large unpopulated districts, the area of which enters into the calculation.
- 15Swp, water, and p rpov, a measure), an instrument for determining the density of bodies, generally of fluids, but in some cases of solids.
- The quantity of mercury or shot inserted depends upon the density of the liquids for which the hydrometer is to be employed, it being essential that the whole of the bulb should be immersed in the heaviest liquid for which the instrument is used, while the length and diameter of the stem must be such that the hydrometer will float in the lightest liquid for which it is required.
- In this case we have w p = W/(N -{- p)lA; or the density of the liquid varies inversely as N+p, that is, as the whole number of scale-divisions between the bottom of the tube and the plane of flotation.
- If we wish the successive divisions of the scale to correspond to equal increments in the density of the corresponding liquids, then the volumes of the instrument, measured up to the successive divisions of the scale, must form a series in harmonical progression, the lengths of the divisions increasing as we go up the stem.
- The greatest density of the liquid for which the instrument described above can be employed is W/V, while the least density is W/(Vd-nlA), or W/(V-Fv), where v represents the volume of the stem between the extreme divisions of the scale.
- But it is clear that if we increase A, the sectional area of the stem, we shall diminish 1, the length of a scale-division corresponding to a given variation of density, and thereby proportionately diminish the sensibility of the instrument, while diminishing the section A will increase land proportionately increase the sensibility, but will diminish the range over which the instrument can be employed.
- The volume of the displaced liquid being then always the same, its density will be proportional to the whole weight supported, that is, to the weight of the instrument together with the weights required to be placed in the scale pan.
- To determine the density of solids heavier than water with this.
- Hence, since the weight of the solid itself is W-w, its density must be (W-w)/(wi-w).
- To use the instrument for liquids of much greater density than water additional weights must be placed in the upper pan, and the "plongeur" is then placed in the lower pan for the purpose of giving to the instrument the requisite stability.
- Proof spirit is defined in the United States as a mixture of alcohol and water which contains equal volumes of alcohol and water at 60° F., the alcohol having a specific gravity of 0.7939 at 60° as compared with water at its maximum density.
- It will thus be seen that the whole length of the stem corresponds to a difference of density of about 04, and one division to about 00074, indicating a difference of little more than a% in the strength of any sample of spirits.
- % by volume of alcohol at 15° C., the highest division of the scale corresponding to the purest alcohol he could obtain (density 7947) and the lowest division corresponding to pure water.
- Tralles's hydrometer differs from Gay-Lussac's only in being graduated at 4° C. instead of 15° C., and taking alcohol of density 7939 at 15.5° C. for pure alcohol instead of 7947 as taken by GayLussac (Keene's Handbook of Hydrometry).
- In Beck's hydrometer the zero of the scale corresponds to density 1 000 and the division 30 to density.
- This table differs slightly from that given above, which has been abridged from the table given in Keene's Handbook of Hydrometry, apparently on account of the equal divisions on Sikes's scale having been taken as corresponding to equal increments of density.
- Any determination of density can be taken only as affording prima facie evidence of the quality of milk, as the removal of cream and the addition of water are operations which tend to compensate each other in their influence on the density of the liquid, so that the lactometer cannot be regarded as a reliable instrument.
- They are employed for taking observations of the density of sea-water.
- The quality varies much, as well as the =colour and density; an Italian sample in the museum at Kew (of a very dark red tint) weighs about 241 lb to the cub.
- The density of the population is 175 to the sq.
- Goldstein 7 was able to show that an increase in the current density is capable of destroying the well-known spectra of the alkali metals, replacing them by quite a new set of lines.
- According to independent experiments by Paschen the radiation of the D line sent out by the sodium flame of sufficient density is nearly equal to that of a black body at 'the same temperature.
- The discussion as to the causes of this widening has turned a good deal on the question whether it is primarily due to changes of density, pressure or temperature, but some confusion has been caused by the want of proper definition of terms. For the cause of this the writer of the present article is jointly with others at any rate partly responsible, and clearness of ideas can only be re-established by investigating the mechanical causes of the effect rather than by applying terms which refer to a different order of physical conceptions.
- But is this alone sufficient to justify us in assigning the widening to increased density?
- Increased density at the same temperature means in the first place a reduction of the average distance between the molecules, but it means also a reduction in the mean free path and an increase in the number of impacts.
- If it is the average distance irrespective of length of path and of number of impacts we should be justified in ascribing the effect to density, but if it is the number of impacts it would be more reasonable to ascribe it to pressure.
- Experimentally we should be confined to a strict investigation of absorption spectra, because in the electric discharge temperature has no definite meaning, and variations of pressure and density are not easily measured.
- Assuming for a moment the change to be one of density and leaving out of account the pressure shift, the cases (e) and (f) point to the fact that it is the closeness of packing of similar molecules which is effective, e.g.
- Experiment (c) is, however, generally taken to mean that this closeness of packing cannot be the sole determining cause, for it is argued that if a closed vacuum tube can show both wide and narrow lines according to the mode of discharge, density alone cannot account for the change.
- When we compare together electric discharges the intensity of which is altered by varying, the capacity, we are unable to form an opinion as to whether the effects observed are due to changes in the density of the luminous material or changes of temperature, but the experiments of Sir William and Lady Huggins 1 with the spectrum of calcium are significant in suggesting that it is really the density which is also the determining factor in cases where different concentrations and different spark discharges produce a change in the relative intensities of different lines.
- The widening of lines does not lend itself easily to accurate measurements; more precise numerical data are obtainable by the study of the displacements consequent on increased density which were discovered and studied by W.
- Schuster suggested that the proximity of molecules vibrating in the same period might be the cause of the diminished frequency, and suggested that according to this view the shifts would be similar if the increase of density were produced by the presence of molecules of a different kind from those whose lines are being examined.
- Fitzgerald 6 suggested as an alternative explanation the change of inductive capacity of the medium due to increased density.
- That orthoboric acid is a tribasic acid is shown by the formation of ethyl orthoborate on esterification, the vapour density of which corresponds to the molecular formula B(0C2H5)3; the molecular formula of the acid must consequently be B(OH) 3 or H 3 B0 3.
- This is expressed by saying that the density of gold is about two and a half times that of iron.
- The product of the volume and density of a body measures what is called its "mass."
- The density is 317 per sq.
- Solutions were not distinguished from definite chemical compounds till John Dalton discovered the laws of definite and multiple proportions, but many earlier observations on the solubility of solids in water and the density of the resulting solutions had been made.
- Equilibrium requires that the available energy and therefore the area of contact should be a minimum, as is demonstrated in Plateau's beautiful experiment, where a large drop of oil is placed in a liquid of equal density and a perfect sphere is formed.
- If the height be not too great, we may assume the density of the vapour to be uniform, and write the difference in vapour pressure at the surfaces of the solvent and of the solution as p - p' = hgo-.
- In the vapour pressure equation p - p' = Pa/p, we have the vapour density equal to M/v 1, where M is the molecular weight of the solvent.
- The density of the liquid is MN/V, where N is the number of solvent molecules, and V the total volume of the liquid.
- Hence we must not assume that the density of the vapour in the surrounding atmosphere is constant, or that the solution, when equilibrium is reached, is of uniform concentration throughout.
- This determination involves a knowledge of the density and of the compressibility of the solution; the latter property is difficult to measure accurately.
- A few concordant determinations of density having been effected, the question was at first regarded as disposed of, until the thought occurred that it might be desirable to try also the more usual method of preparation in which the oxygen is removed by actual oxidation of copper without the aid of ammonia.
- Whatever were the means employed to rid air of accompanying oxygen, a uniform value of the density was arrived at, and this value was z% greater than that appertaining to nitrogen extracted from compounds such as nitrous oxide, ammonia and ammonium nitrite.
- Storage for eight months did not disturb the density of the chemically extracted gas, nor had the silent electric discharge any influence upon either quality.
- ("On an Anomaly encountered in determining the Density of Nitrogen Gas," Proc. Roy.
- The density of argon, prepared and purified by magnesium, was found by Sir William Ramsay to be 19.941 on the O = 16 scale.
- After two or three hours the liquid is diluted till its density falls to 1.23, when it is passed through filter-presses to remove the insoluble ferric oxide and silica.
- Its vapour density at temperatures above 750 corresponds to the formula AlCl 3 j below this point the molecules are associated.
- The extremes of density of population are found in the provinces of North Holland and South Holland on the one hand, and Drente on the other.
- That for the thin-walled water mains must combine strength with the fluidity needed to enable it to run freely into its narrow moulds; that for most machinery must be soft enough to be cut easily to an exact shape; that for hydraulic cylinders must combine strength with density lest the water leak through; and that for car-wheels must be intensely hard in its wearing parts, but in its other parts it must have that shock-resisting power which can be had only along with great softness.
- Of these several qualities which cast iron may have, fluidity is given by keeping the sulphur-content low and phosphoruscontent high; and this latter element must be kept low if shock is to be resisted; but strength, hardness, endurance of shock, density and expansion in solidifying are controlled essentially by the distribution of the carbon between the states of graphite and cementite, and this in turn is controlled chiefly by the proportion of silicon, manganese and sulphur present, and in many cases by the rate of cooling.
- To sum this up, as graphite is replaced by carbon combined as cementite, the hardness, brittleness and density increase, and the expansion in solidification decreases, in both cases continuously, while the tensile strength increases till the combined carbon-content rises a little above I %, and then in turn decreases.
- 33) upon the protruding end, F, of the rod, transmitted to the still undrawn part, E, squeezes the yielding metal of the rod against the hard unyielding die, C. As when a half-opened umbrella is thrust ferrule-foremost between the balusters of a staircase, so when the rod is drawn forward, its yielding metal is folded and forced backwards and centrewards by the resistance of the unyielding die, and thus it is reduced in diameter and simultaneously lengthened proportionally, without material change of volume or density.
- As regards density of colour the skunk or black marten has the blackest fur, and some cats of the domestic kind, specially reared for their fur, are nearly black.
- Skins of a pale bluish tone are generally used in their natural state for stoles, boas and muffs, but the less clear coloured skins are dyed in beautiful shades similar in density to the dark and valuable sables from Russia, and are the most effective skins that can be purchased at a reasonable price.
- A very prolific rodent of the amphibious class obtained from Canada and the United States, similar in habit to the English vole, with a fairly thick and even brown underwool and rather strong top dark hair of medium density.
- They have long been known as "sables," doubtless owing to the density of colour to which many of them attain, and they have always been held in the highest esteem by connoisseurs as possessing a combination of rare qualities.
- The Yakutsk, Okhotsk and Kamschatka sorts are good, the last being the largest and fullest furred, but of less density of colour than the others.
- iroXb, many) was chosen for compounds like butylene, C 4 H 8, and ethylene, C 2 H 4, corresponding to the same composition in weight but differing in molecular formula, and having different densities in gas or vapour, a litre of butylene and isobutylene weighing, for instance, under ordinary temperature and pressure, about 2.5 gr., ethylene only one-half as much, since density is proportional to molecular weight.
- It is different, however, with physical properties, density, &c.; at present we have no fixed rules which enable us to predict quantitatively the differences in physical properties corresponding to a given difference in structure, the only general rule being that those differences are not large.
- The coefficient of expansion increases very rapidly above 750°, and diminishes very rapidly at low temperatures; the maximum density is attained about - 42° C.
- m.; estimated population (1901) 67,399, showing a density of six persons to the square mile.
- Its mean value may be determined most satisfactorily from the weight and the density.
- No allowance was made for the variation of density with temperature, or for the variation of the distance between the thermometers, owing to the expansion of the bar.
- Clerk Maxwell, who predicted that the effect should be independent of the density within wide limits.
- This, at first sight, paradoxical result is explained by the fact that the mean free path of each molecule increases in the same proportion as the density is diminished, so that as the number of molecules crossing each square centimetre decreases, the distance to which each carries its momentum increases, and the total transfer of momentum is unaffected by variation of density.
- By similar reasoning the thermal conductivity of a gas should be independent of the density.
- Baille about 1870 a repetition of Cavendish's experiment for determining the mean density of the earth, his original work was mainly concerned with.
- Its vapour density has been determined by Nilson and Pettersson, and corresponds to the molecular formula BeC12.
- Density thgllsh per q.
- Density of Population.In respect of density of population, Germany with (1900) 269~9 and (905) 290.4 inhabitants to the square mile is exceeded in Europe only by Belgium, Holland and England.
- There it is only in the valleys of the larger navigable rivers and on the southern border of the plain that the density exceeds 200 inhabitants per square mile.
- In all these the density exceeds 400 inhabitants to the square mile, and in the case of Saxony rises to 750.
- For the size and density of particles which he considers most likely, Arrhenius calculates the time required to travel from the sun as forty-six hours.
- By modifying the hypothesis as to the size and density, times appreciably longer or shorter than the above would be obtained.
- The average density is extremely high for a country which lives almost exclusively by agriculture, and is much higher than the average for Italy in general, 293 per sq.
- In parts of Menufia, a Delta province, the density rises to 1352 per sq.
- In 1901 the average density of the population of Denmark was 165.2 to the square mile, but varied much in the different parts.
- - Assuming that each gallon of sea water contains 0.2547 lb of salt, and allowing an average density 2.24 for rocksalt, it has been computed that the entire ocean if dried up would yield no less than four and a half million cubic miles of rock-salt, or about fourteen and a half times the bulk of the entire continent of Europe above high-water mark.
- The density at first was 1.02.
- This goes on till a density of 1.1315 is attained, when hydrated calcium sulphate begins to deposit, and continues till specific gravity 1.2646 is reached.
- At a density of 1.218 the deposit becomes augmented by sodium chloride, which goes down mixed with a little magnesium chloride and sulphate.
- In the former case it is often difficult to obtain the brine at a density even approaching saturation, and chambers and galleries are sometimes excavated within the saliferous beds to increase the dissolving surface, and water let down fresh is pumped up as brine.
- Its vapour density at 1728° corresponds to the molecule TI 2.
- The coat is remarkable for its density and compactness; the general colour of the head and upper parts being clove-brown, with more or less white or whitish grey on the under parts and inner surfaces of the limbs, while there is also some white above the hoofs and on the muzzle, and there may be whitish rings round the eyes; there is a white area in the region of the tail, which includes the sides but not the upper surface of the latter; and the tarsal tuft is generally white.
- In all cases the strength increases proportionately with the density of the wood.
- The great fluidity of bronze when melted, the slightness of its contraction on solidifying, together with its density and hardness, make it especially suitable for casting, and allow of its taking the impress of the mould with extreme sharpness and delicacy.
- One of the purposes of the expedition was to discover whether the rate of combustion of a candle varies with the density of the atmosphere in which it is burnt, a question which was answered in the negative.
- It is not possible to deduce a more satisfactory value from the latent heat and the change of density, because these constants are very difficult to determine.
- He found for natural pond-ice a density 0.9179 and for artificial ice 0.9161.
- 198, p. 463) also found a density.
- If such variations of density exist, they may introduce some uncertainty in the absolute values of results obtained with the ice calorimeter, and may account for some of the discrepancies above enumerated.
- A Favourite Temperature To Select Is 4° C., The Temperature Of Maximum Density, Since At This Point The Specific Heat At Constant Volume Is The Same As That At Constant Pressure.
- Employing Pressures Between 7 And 27 Atmospheres, He Found That The Specific Heat Of Air Between 10 And Ioo C. Increased Very Slightly With Increase Of Density, But That Of Co 2 Increased Nearly 3% Between 7 And 21 Atmospheres.
- The Following Formulae Represent His Results For The Specific Heat S At Constant Volume In Terms Of The Density D In Gms. Per C. C.: Air, S = 0.1715 0 028D, C02, S = 0.165 0.213D } O 34D2.
- But this cannot continue indefinitely; when the density is too great the matter ceases to behave as a true gas, and the contraction is insufficient to maintain the heat.
- Density of Stars.
- The mean density of the sun is about 13 times that of water; but many of the stars, especially the brighter ones, have much lower densities and must be in a very diffused state.
- The Orion stars have the highest temperature of all and have admittedly the greatest surfaceluminosity, but the extreme brilliancy of i Orionis in proportion to its mass must be mainly due to a small density.
- For the Algol variables it is possible to form even more direct calculations of the density, for from the duration of the eclipse an approximate estimate of the size of the star may be made.
- Roberts concluded in this way that the average density of the Algol variables and their eclipsing companions is about one-eighth that of the sun.
- Myers found a density a little less than that of air; the density is certainly small, but J.
- If the uniform distribution extends indefinitely, or as far as the telescope can penetrate, the star-ratio should have the theoretical value 3.98, 1 any decrease in density or limit to the distribution of the stars will be indicated by a continual falling off in the star-ratio for the higher magnitudes.
- He indicated on planispheres the varying density of distribution of the stars over the sky.
- On these the belt of greatest density can be easily traced, and it follows very closely the course of the Milky Way; but, whereas the latter is a belt having rather sharply defined boundaries, the star-density decreases gradually and continuously from the galactic equator to the galactic poles.
- The following table shows the density with which stars brighter than the ninth magnitude are distributed in each of nine zones into which Seeliger divided the heavens and more generally recognized that the stars are not unrelated; they are parts of a greater system, and we have to deal with, not merely the history of a number of independent units, but with a far vaster conception, the evolution and development of an ordered universe.
- It can be shown that, if the density of distribution of the stars through infinite space is nowhere less than a certain limit (which may be as small as we please), the total amount of light received from them (assuming that there is no absorption of light in space) would be infinitely great, so that the background of the sky would shine with a dazzling brilliancy.
- If the stars were all of the same intrinsic brightness it is evident that the comparison of the number of stars of successive magnitudes would show directly where the decreased density of distribution began.
- No doubt many of the lucid stars which appear to lie in the Milky Way actually belong to it, and the presence of this unique cluster helps to swell the numbers along the galactic equator; but, for example, the increased density between latitudes 30° to 50° (both north and south) as compared with the density at the poles cannot be attributed to the Galaxy itself, for the Galaxy passes nowhere near these zones.
- The star-gauges of the Herschels exhibit a similar result; the Herschels counted the number of stars visible with their powerful telescopes in different regions of the sky, and thus formed comparative estimates of the density of the stars extending to a very high magnitude.
- In both divisions there is an average density of little more than 1 to every 2 sq.
- While working on the olefines he noticed that a change takes place in the density of the vapour of amylene hydrochloride, hydrobromide, &c., as the temperature is increased, and in the gradual passage from a gas of approximately normal density to one of half-normal density he saw a powerful argument in favour of the view that abnormal vapour densities, such as are exhibited by sal-ammoniac or phosphorus pentachloride, are to be explained by dissociation.
- In the variety, size and density of their growth these forests remind one of the tropics.
- Michell described it in his proposal of a method for obtaining the mean density of the earth.
- P. ponderosa, the yellow pine of the Pacific coast of America, belongs to this section; it is a fine timber tree deserving of notice from the extreme density of its wood, which barely floats in water; it abounds in some parts of the western range of the Rocky Mountains, and is the most widely distributed pine tree of the mountain forests of western North America.
- His laborious operations for determining the mean density of the earth, carried on by Henry Cavendish's method (1838-1842), yielded for it the authoritative value of 5.66.
- On the emission theory the velocity should be accelerated by an increase of density in the medium; on the wave theory, it should be retarded.
- The vapour density of antimony at 1572° C. is 10.74, and at 1640 0 C. 9.78 (V.
- He maintained that there is a rapid variation of density near the surface of a liquid, and he gave very strong reasons, which have been only strengthened by subsequent discoveries, for believing that this is the case.
- He proceeded to an investigation of the equilibrium of a fluid on the hypothesis of uniform density, and arrived at the conclusion that on this hypothesis none of the observed capillary phenomena would take place, and that, therefore, Laplace's theory, in which the density is supposed uniform, is not only insufficient but erroneous.
- Laplace assumed that the liquid has uniform density, and that the attraction of its molecules extends to a finite though insensible distance.
- The only difference is in the manner in which this quantity H depends on the law of the molecular forces and the law of density near the surface of the fluid, and as these laws are unknown to us we cannot obtain any test to discriminate between the two theories.
- In more recent times the method of Gauss has been modified so as to take account of the variation of density near the surface, and its language has been translated in terms of the modern doctrine of the conservation of energy.'
- He formed a mixture of alcohol and water of the same density as olive oil, and then introduced a quantity of oil into the mixture.
- In like manner the density, p, is sensibly equal to the constant quantity po, which is its value in the interior of the liquid, except within a distance e of the bounding surface.
- Hence if V is the volume of a mass M of liquid bounded by a surface whose area is S, the integral M = f f f pdx dydz, (I) where the integration is to be extended throughout the volume V, may be divided into two parts by considering separately the thin shell or skin extending from the outer surface to a depth within which the density and other properties of the liquid vary with the depth, and the interior portion of the liquid within which its properties are constant.
- If we suppose a normal v less than E to be drawn from the surface S into the liquid, we may divide the shell into elementary shells whose thickness is dv, in each of which the density and other properties of the liquid will be constant.
- In such a film it is possible that no part of the liquid may be so far from the surface as to have the potential and density corresponding to what we have called the interior of a liquid mass, and measurements of the tension of the film when drawn out to different degrees of thinness may possibly lead to an estimate of range of the molecular forces, or at least of the depth within a liquid mass, at which its properties become sensibly uniform.
- If we take the axis of z normal to either surface of the film, the radius of curvature of which we suppose to be very great compared with its thickness c, and if p is the density, and x the energy of unit of mass at depth z, then o- = f o dz, (16) and e = f a xpdz,.
- On the hypothesis of uniform density we shall find that this is true for films whose thickness exceeds The symbol x is defined as the energy of unit of mass of the substance.
- If we next write f II (f) d f =, P(z), (24) then 27rmagz) will represent - (I) The work done by the attractive force while a particle m is brought from an infinite distance to a distance z from an infinitely thin stratum of the substance whose mass per unit of area is Z o; (2) The attraction of a particle m placed Q 2 at a distance z from the plane surface of an infinite solid whose density is a.
- To find the work done when m is brought to the point P in the neighbourhood of a solid body, the density of which is a function of the depth v below the surface, we have only to write instead of a pdz, and to integrate ?
- In the form of the theory given by Laplace, the density of the liquid was supposed to be uniform.
- phenomena would not take place unless the density varied rapidly near the surface.
- In this assertion we think he was mathematically wrong, though in his own hypothesis that the density does actually vary, he was probably right.
- In fact, the quantity 41rp 2 K, which we may call with van der Waals the molecular pressure, is so great for most liquids (5000 atmospheres for water), that in the parts near the surface, where the molecular pressure varies rapidly, we may expect considerable variation of density, even when we take into account the smallness of the compressibility of liquids.
- If we suppose that the number of molecules within the range of the attraction of a given molecule is very large, the part of the pressure arising from attraction will be proportional to the square of the number of molecules in unit of volume, that is, to the square of the density.
- If the density be a, the attraction between the whole of one side and a layer upon the other distant z from the plane and of thickness dz is 27r6 2 P(z)dz, reckoned per unit of area.
- If a i, a 2 represent the densities of the two infinite solids, their mutual attraction at distance z is per unit of area 21ra l a fZ '(z)dz, (30) or 27ra l 02 0(z), if we write f 4,(z)dz=0(z) (31) The work required to produce the separation in question is thus 2 7ru l a o 0 (z)dz; (32) and for the tension of a liquid of density a we have T = a f o 0 (z)dz.
- The early writers on capillary action supposed that the diminution of capillary action was due simply to the change of density corresponding to the rise of temperature, and, therefore, assuming the surface-tension to vary as the square of the (37)?(f) =eP f (38) density, they deduced its variations from the observed dilatation of the liquid by heat.
- Suppose that the transition from o to s is made in two equal steps, the thickness of the intermediate layer of density la being large compared to the range of the molecular forces, but small in comparison with the radius of curvature.
- Mag., 1883, P. 315) According to Laplace's hypothesis the whole energy of any number of contiguous strata of liquids is least when they are arranged in order of density, so that this is the disposition favoured by the attractive forces.
- The upper surface of this column is not level, so that the height of the column cannot be directly measured, but let us assume that h is the mean height of the column, that is to say, the height of a column of equal weight, but with a flat top. Then if r is the radius of the tube at the top of the column, the volume of the suspended column is 717 2 12, and its weight is 7rpgr 2 h, when p is its density and g the intensity of gravity.
- We Will Assume That When, As In Most Cases, Viscosity Maybe Neglected, The Mass (M) Of A Drop Depends Only Upon The Density (V), The Capillary Tension (T), The Acceleration Of Gravity (G), And The Linear Dimension Of The Tube (A).
- For All Fluids And For All Similar Tubes Similarly Wetted, The Weight Of A Drop Would Then Be Proportional Not Only To The Diameter Of The Tube, But Also To The Superficial Tension, And It Would Be Independent Of The Density.
- From this the weight of a drop of any liquid of which the density and surface tension are known, can be calculated.
- Calculated as if the density were the same as in a normal state, the thickness of the film is found to be about two millionths of a millimetre.
- F(ka), (2) where, as before, T is the superficial tension, p the density, and F is given by the following table: - The greatest value of F thus corresponds, not to a zero value of k 2 a 2, but approximately to k 2 a 2 = 4858, or to A = 4.508 X 2a.
- Then if p be the density of the upper liquid, and Q that of the lower liquid, and P the original pressure at the surface of separation, then when the surface receives an upward displacement z, the pressure above it will be P - pgz, and that below it will be P - Ogz, so that the surface will be acted on by an upward pressure (p - Q)gz.
- If K is the height of the flat surface of the drop, and k that of the point where its tangent plane is vertical, then T = 1(K - k) 2gp. Quincke finds that for several series of substances the surfacetension is nearly proportional to the density, so that if we call Surface-Tensions of Liquids at their Point of Solidification.
- As regards numbers, it occupies the second place amongst the Austrian provinces, coming after Galicia, and as regards density of population it stands third, Silesia and Lower Austria, which contains Vienna, standing higher.
- Its vapour density has been determined at 2000°, and corresponds to a monatomic molecule.
- It is very tolerant of fresh water, fattening best, as does the oyster, in water of density 1014 (the density of the water of the North Sea being 1026).
- This allowance of space has been ascertained by experience to be sufficient, not only for comfort, but also for subsistence for one day, provided that the density of the ordinary civil population is not less than 200 persons to the square mile.
- This comes of the action and reaction of matter, the resistance experienced varying according to the density of the atmosphere and the shape, extent and velocity of the body acting upon it.
- 2.1 Natural Divisions 2.2 Lake District 2.3 Pennine Region 2.4 Wales 2.5 Cornwall and Devon 2.6 The Jurassic Belt 2.7 The Chalk Country 2.8 The Fenland 2.9 The Weald 2.10 The London Basin 2.11 The Hampshire Basin 2.12 Communications 2.13 Density of Population 2.14 Political Divisions
- China clay from the decomposing granites; tin and copper ore, once abounding at the contacts between the granite and the rocks it pierced, were the former staples of wealth, and the mining largely accounts for the exceptional density of population in Cornwall.
- In almost every case the plain along the foot of an escarpment bears a line of villages and small towns, and on a good map of density of population the lines of the geological map may be readily discerned.
- At the census of 1880 the density of the population was 1 8 and in 1890 it was 2.6.
- A common type of mirage is the appearance of an isolated lake frequently seen in hot sandy deserts, as in the Sahara, Turkestan, &c. The explanation is as follows: The sand, being abnormally heated by the solar rays, causes the neighbouring air to expand, consequently its density, and therefore its refractive index, is diminished, and attains a minimum value in the lowest layers.
- It may happen that the change in density is so great that only the upper rays reach the eye; we are then met with the curious illusion of seeing inverted ships in the clouds, although nothing is visible on the ocean.
- The distribution of density is similar to that attending a desert mirage, but the transition is not so abrupt.
- material, having the maximum refractive index along the central axis, have been prepared, and reproduce the effects caused by abnormal distribution of the density of the atmosphere.
- In a similar way the absorption of light in the coloured gas chlorine is found to be unaltered if the thickness is reduced by compression, because the density is increased in the same ratio that the thickness is reduced.
- Its density at o° is 1.836; this regularly diminishes up to the melting-point, 44.3°, when a sudden drop occurs.
- It boils at 290°, forming a colourless vapour which just about the boiling-point corresponds in density to tetratomic molecules, P4; at 1500° to 1700°, however, Biltz and Meyer detected dissociation into P2 molecules.
- It is a dark red microcrystalline powder, insoluble in carbon bisulphide, oil of turpentine, &c., and having a density of 2.2.
- Vapour density and cryoscopic determinations point to the double formula, P406.
- The vapour density at about 1400° is 230, i.e.
- Its vapour density at 1400° points to the double formula (West, Jour.
- It sublimes when heated, but under pressure it melts at 148°, giving a normal vapour density, but on further heating it dissociates into the trichloride and chlorine; this dissociation may be retarded by vapourizing in an atmosphere of chlorine.
- But as the mean density exceeds that of water, and probably falls but little from the centre to the surface, these gases are gases only in the sense that if the pressure of neighbouring and outward parts gravitating towards the centre were relaxed, they would expand explosively, as we see happening in the eruptive prominences.
- Its temperature must be dominated directly or indirectly by the surface radiation, and since the matter is gaseous and so open to redistribution, the same is true of density and pressure.
- We then find that the density would increase as we go outwards, at first slowly, but finally with extreme rapidity, the last tenth of the radius comprising half the mass.
- Only near the surface would they become violent, and only there would there be a rapid fall of temperature and density.
- Indeed it seems that, in the final distribution of density throughout the part which is not subject to violent convection currents, it must increase slightly from the centre outwards, since the currents would cease altogether as soon as 'a uniform state was restored.
- The theory refers to radiation homogeneous at all points within a single closed boundary maintained at uniform temperature; in the actual case we have a double boundary, one the sun's surface, and the other infinitely remote, or say, non-existent, and at zero temperature; and it is assumed that the density of radiation in the free space varies inversely as the squares of the distance from the sun.
- If we suppose the sun's mass once existed in a state of extreme diffusion, the energy yielded by collecting it into its present compass would not suffice to maintain its present rate of radiation for more than 17,000,000 years in the past; nor if its mean density were ultimately to rise to eight times its present amount, for more than the same period in the future.
- This supposes the present density nearly uniform; if it is not uniform, any amount added to the former period is subtracted from the latter.
- It is easy to calculate that this would be produced by an annual fall of matter equal to one nineteen millionth of the sun's mass, which would make an envelope eight metres thick, at the sun's mean density; this would be collected during the year from a spherical space extending beyond the orbit of Jupiter.
- The earth would intercept an amount of it proportional to the solid angle it subtends at the sun; that is to say, it would receive a deposit of meteoric matter about one-tenth of a millimetre, of density say 2, over its whole surface in the course of the year.
- Julius's phenomenon seems inseparable from grazing incidence, and hence any explanation it supplies depends upon his hypothetical tubular structure for layers of equal density.
- Mean density: 256 X mean density of earth =1.415.
- The passes across these ranges are comparatively low, but they are difficult because of the precipitous character of their Pacific slopes and the density of the vegetation on them.
- The resistance of clay to percolation by water depends chiefly upon the density of the clay, while that density is rapidly reduced if the clay is permitted to absorb water.
- On the restoration of the pressure, the density will be again increased by the reduction of the water-filled interstices, and the percolation will be correspondingly checked.
- Thus they not only penetrate all cavities in an exceedingly intrusive manner, but exert pressures in all directions, which, owing to the density of the asphalt, are more than 40 greater than would be produced by a corresponding depth of water.
- It is obvious that the angles at the base of such a hypothetical dam must depend upon the relation between its density and that of the water.
- It can be shown, for example, that for masonry having a density of 3, water being 1, the figure of minimum section is a right-angled triangle, with the water against its vertical face; while for a greater density the water face must lean towards the water, and for a less density away from the water, so that the water may lie upon it.
- As the density of the heaviest rocks is only 3, that of a masonry dam must be below 3, and in practice such works if well constructed vary from 2.2 to 2.6.
- thick of a monolithic dam, subject to the pressure of water against its vertical side to the full depth ab= d in feet, the horizontal _ eL 2 pressure of water against the section of the dam, inI creasing uniformly with the depth, is properly represented by the isosceles right-angled triangle abe, in which be is the maximum water-pressure due to the Cent full depth d, while the area 2 abe = d is t h e total hor12 d3 6 If x be the width of the base, and p the density of the masonry, the weight of the masonry in terms of a cubic foot of water will be acting at its centre of gravity g, situated at 3x from the outer toe, and the moment of resistance to overturning on the outer toe, p x 2 d (2) In countries where good clay or retentive earth cannot be obtained, numerous alternative expedients have been adopted with more or less success.
- (3) That is to say, for such a monolith to be on the point of overturning under the horizontal pressure due to the full depth of water, its base must be equal to that depth divided by the square root of twice the density of the monolith.
- For a density of 2.5 the base would therefore be 44.7% of the height.
- The late Sir Benjamin Baker, F.R.S., suggested that the stresses might be measured by experiments with elastic models, and among others, experiments were carried out by Messrs Wilson and Gore a with indiarubber models of plane sections of dams (including the foundations) who applied forces to represent the gravity and water pressures in such a manner that the virtual density of the rubber was increased many times without interfering with the proper ratio between gravity and water pressure, and by this means the strains produced were of sufficient magnitude to be easily measured.
- The line of pressures as generally given for this dam with the reservoir full, on the hypothesis that the density of the masonry was a little over 2, is shown by long and short dots in fig.
- Materials actu ally collected from the dam indicate that the mean density did not exceed I.
- of the outer face, and was more nearly five-sixths than two-thirds of the width of the dam distant from the water face; there must, therefore, have been considerable vertical tension at the water face, variously computed according to the density assumed at from 14 to I q ton per square foot.
- And the weight of air displaced depends upon the density of the air at the time of weighing, and therefore the barometer reading must be taken.
- m., and a population (1901) of 233,377, showing an increase of 8% in the decade and a density of 71 inhabitants to the sq.
- and a population (1901), of 1,076,280, showing an increase of 8% in the decade and giving a density of 63 inhabitants to the square mile.
- and the population shows a density of 1 77.5 inhabitants to the square mile.
- The former investigates essentially general properties, such as the weight and density, the relation between pressure, volume and temperature (piezometric and thermometric properties), calorimetric properties, diffusion, viscosity, electrical and thermal conductivity, &c., and generally properties independent of composition.
- These subjects are discussed in the articles Density; Thermometry; Calorimetry; Diffusion; Conduction Of Heat; and Condensation Of Gases.
- The retort carbon products* formed as a dense deposit on the crown of the retort by the action of the high temperature on the hydrocarbons is, however, carbon in a very pure form, and, on account of its density, is largely used for electrical purposes.
- The population of Wisconsin in 1890 was 1,686,880 (exclusive of 6450 persons specially enumerated); in 1900 the total was 2,069,042 - an increase of 22.2% on the basis of the total at each enumeration; and in 1910 it reached a total of 2,333,860.2 The density of the population in 1910 was 42.2 to the square mile.
- A temperature of 70, and a reversal of the current (of low density) between two cast iron electrodes every few minutes, are the best working conditions.
- It fuses at a red-heat, and volatilizes at a yellow-heat; its vapour density at 1300°-1400° corresponds to the formula FeC12.
- Vapour density determinations at 448° indicate a partial dissociation of the double molecule Fe2Cl6I on stronger heating it splits into ferrous chloride and chlorine.
- In 1826 and 1828, Whewell was engaged with Airy in conducting experiments in Dolcoath mine, Cornwall, in order to determine the density of the earth.
- and a population (1901) of 366,507, giving a density of 177 inhabitants to the square mile.
- m., and a population (Igor) of 777,338, giving an average density of 30 inhabitants to the square mile.
- This is one of the most troublesome problems in astronomy because, owing to the ever varying density of the atmosphere, arising from differences of temperature, and owing to the impossibility of determining the temperature with entire precision at any other point than that occupied by the observer, the amount of refraction must always be more or less uncertain.
- Not the slightest change in the direction of such a star when in this position has ever been detected, and it is certain that if any occurs it can be but a minute fraction of a second of arc. As an atmosphere equal to ours in density would produce a deviation of an important fraction of a degree, it may be said that the moon can have no atmosphere exceeding in density the b b l o o that of the earth.
- I :81.53 t 047 Density (earth's as I) 0.60736 Density (water's as 1, and earth's assumed as 5).
- As seen from the above table the density of the population is unequal in the various crown lands.
- The vapour density is 10.6 (air =1) at 564° C., corresponding to a tetratomic molecule As; at a white heat the vapour density shows a considerable lowering in value, due to the dissociation of the complex molecule.
- In the bestwatered districts agriculture is naturally of the greatest importance, except where the density of the forest renders the work of clearing too arduous.
- As water expands on freezing, so conversely ice contracts on melting; and the ice-cold water thus formed continues to contract when heated until it has reached its point of maximum density, the temperature at which this occurs being about 39° Fahr.
- or 4° C. Above this point water continuously expands, and at no temperature is it less dense than ice as is shown by the following table: - Density of ice at o°C. = 9175 „ water at o°C. = 99988 4°C. = 1.00000 Io °C. _ 99976 Ioo°C. _ 95866 Under the influence of heat, ice itself behaves as most solids do, contracting when cooled, expanding when heated.
- Ice forms over fresh water if the temperature of the air has been for a sufficient time at or below the freezing-point; but not until the whole mass of water has been cooled down to its point of maximum density, so that the subsequent cooling of the surface can give rise to no convection currents, is freezing possible.
- If unit mass of a solution contain m grammes of an active substance and if o be the density and p be the rotary power of the solution, the specific rotary power is defined by p/m8, and the molecular rotary power is obtained from this by multiplying by the hundredth part of the molecular mass.
- Fresnel obtained his formulae by assuming that the optical difference of media is due to a change in the effective density of the ether, the elasticity being the same - an assumption inconsistent with his theory of double refraction - and was led to the result that the vibrations are perpendicular to the plane of polarization.
- Franz Neumann and James MacCullagh, starting from the opposite assumption of constant density and different elasticities, arrived at the same formulae for the intensities of the reflected light polarized in the principal azimuths, but in this case the vibrations must be regarded as parallel to the plane of polarization.
- 104) has, however, shown that the polarization of the light from the sky can only be explained on the elastic solid theory by Fresnel's hypothesis of a different density, and from the study of Hertzian oscillations, in which the direction of the electric vibrations can be a priori assigned, we learn that when these are in the plane of incidence there is no reflection at a certain angle, so that the electric force is perpendicular to the plane of polarization.
- "Fruitful as the miscibility of gases has been in interesting speculations, the experimental information we possess on the subject amounts to little more than the well-established fact that gases of a different nature when brought into contact do not arrange themselves according to their density, but they spontaneously diffuse through each other so as to remain in an intimate state of mixture for any length of time."
- DBbereiner he substituted a glass tube closed by a plug of plaster of Paris, and with this simple appliance he developed the law now known by his name "that the diffusion rate of gases is inversely as the square root of their density."
- 15260.00 The density of the water averages 1.166.
- At 300 metres its density is 1.253.
- The play of brilliant colours and of ever-changing contrasts of light and shade on those rugged mountain-sides and on the surface of the sea itself might have been expected to appeal to the most prosaic. The surface of the sea is generally smooth (seldom, however, absolutely inert as the pilgrims represented it), but is frequently raised by the north winds into waves, which, owing to the weight and density of the water, are often of great force.
- At the beginning of 1905, the state contained 181,roo people, giving a density of 6.9 persons per square mile.
- The density of population for the whole government is estimated as 3.7 or 4 per sq.
- The density of population in districts outside the influence of European government sinks to 1 and less per sq.
- The density of population being calculated at about 2.7 to 3 per sq.
- This principle is capable of very wide extension, the blast furnace being mainly limited in height by the strength the column of materials or "burden" has to resist crushing, under the weight due to the head adopted, and the power of the blowing engine to supply blast of sufficient density to overcome the resistance of the closely packed materials to the free passage of the spent gases.
- When melted the products separate on the bed (which is made of closely packed sand or other infusible substances), according to their density; the lighter earthy matters forming an upper layer of slag are drawn out by the slag hole K at the flue end into an iron wagon or bogie, while the metal subsides to the bottom of the bed, and at the termination of the operation is run out by the tap hole L into moulds or granulated into water.
- At that time the maximum potential development considered feasible for the island was a low density business park.
- Features High density ' rebound ' fabric assists in shock absorption.
- accentuated when they occur in the high density range.
- Her team recently announced it had created the highest density electronically addressable memory reported to date, a 64-bit memory using molecules as switches.
- aerogel material, the lowest density solid material in the world.
- As the aircraft becomes lighter, it flies higher in air of lower density to maintain the same airspeed.
- annealing of the films in precisely controlled atmospheres showed that the ferromagnetism in our films is not linked to the carrier concentration density.
- The local density approximation (LDA) is shown to be inadequate for calculating the band-gap narrowing.
- About 60 million cubic meters of dome and crater wall traveled to the south as a debris avalanche and pyroclastic density currents.
- backscattering coefficient and above-ground biomass density.
- These values depend on the density of protons and neutrons, which are collectively called baryons.
- baryon density in the local universe.
- With the density of baryonic matter known, the total density can be determined from measuring the baryon fraction.
- The living quarters must always be kept dry as it is said that wet bedding can affect density on feet.
- In winter wheat, crop density is an important factor in limiting seed production by red dead-nettle through the effect on weed biomass.
- The U.S. paper industry has managed to come up with a truly bizarre way of specifying the density of paper.
- The lower density of ice is caused by its structure, a hydrogen bonded tetrahedral network similar to that of diamond.
- bone density at the wrist within the twin pairs.
- bone mineral density changes were compared with a control group of 15 untreated women.
- The power density at the core of a fast breeder reactor is more than four times higher than that in a thermal reactor.
- Density was rather low to meet my expectations, except for a great abundance of Flavescent and Brown-breasted bulbuls soon considered common.
- To be an efficient fat burner you need to increase your muscle density.
- calcific density.
- Calculates the relaxing density contribution to the derivative of the energy wrt Cartesian coordinates.
- The density, about 0.2 grams per cubic centimeter, means it is a gas giant like Jupiter.
- The solubilized mixture was then resolved by sucrose density gradient centrifugation.
- After density gradient centrifugation, virus particles were detected in the density zone of 1.34 g/ml.
- Monocytes and lymphocytes may also be obtained fresh from human blood using density centrifugation to isolate distinct cell types according to their different densities.
- The beams are then decked in 12mm (15mm on 900mm deep bays) high density chipboard panels.
- A temporary fall in high and rise in low density lipoprotein cholesterol was observed in the study population.
- Salinity is therefore a major factor in the density driven global scale thermohaline circulation.
- Difference electron density for a molecule of AMPPNP is observed in the kinase active site cleft.
- coincident with a low density anomaly.
- column density of Galactic Hydrogen from Stark et al.
- common logarithm of intensity or flux density in arbitrary units.
- convolve a density image is constructed by convolving the image data with a Gaussian density kernel.
- critical densityemperature above 90 K is readily obtained, however the critical current density is only of order of 10 5 A/cm 2.
- Weed population density may be markedly reduced using crop rotation but there has been little experimentation.
- cross-link density is N / V o.
- This increases its density, so it sinks and flows back south in a deep current.
- At the active electrode there is a high current density due to the small area of the electrode.
- deficient patients increases bone mineral density.
- The RNHRD uses the Hologic Acclaim bone densitometer, which allows bone density to be assessed in a few minutes.
- density of the ionosphere.
- Pea Forage Yield Forage yields of peas increased significantly with increased sowing density in all but the late pea harvest in 1999.
- The current record for areal density for a commercially released drive is 133 gigabits per square inch, according to Toshiba.
- high density of dots in a region denotes high electron density.
- The low energy density feeds require a large volume plant to process them.
- Factors to be considered when selecting an appropriate scanner include optical resolution, optical density, bit depth and scanning time.
- density lipoprotein (HDL) cholesterol levels also did not show any significant change over the week.
- density polyethylene.
- density fibreboard and they are fitted during the factory construction as an integral part of the cabinetry.
- density foam to fluorescent color acrylics.
- density matrix, array of atom charges (empty on input ).
- density gradient is steepest are computed by the program.
- bone density We do not know by how much bone density recovers.
- M Magnetic flux density A measure of the magnetic effect induced in a medium by an external field.
- I have seen #1 ranking with a keyword phrase density of only 0.5% to over 20% .
- The bone mineral density changes were compared with a control group of 15 untreated women.
- There were no significant differences in cortical volumetric bone mineral density (vBMD) at the radius or tibia diaphysis between the groups.
- Drought is also thought to be a factor causing dieback in hedgerow trees, which are not included in the UK crown density survey.
- dislocation density will have a large effect on how easily the material can be deformed.
- For London, dwelling density rose from 48 new dwellings per hectare in 1993 to 56 in 2000.
- earthworm density in turn dictates the territory size - there must be several good feeding grounds for the group.
- The paper discusses the possibility that horizontal advection combined with horizontal gradients in the plasma density can contribute to the radar echoes.
- electron density.
- Radio tomographic imaging as an aid to modeling of ionospheric electron density.
- embolus from atrial myxoma Findings Subtle reduced density in the left basal ganglia on CT.
- They discussed traffic density with ATC, and eventually declared an emergency in order to get priority for landing.
- entropy ions are strongly hydrated, with small or negative entropies of hydration, creating local order and higher local density.
- Prof. C.C. Taylor: classification, image analysis, statistical pattern recognition, bioinformatics, nonparametric density estimation, spatial statistics.
- excellence in journalism with the delicate art of keyword density as it relates to search engine optimization.
- This loss of electron density results in a reduction of electron impact excitation reactions in that region.
- For damped exponentials, the ordering is by energy spectral density at the peak frequency.
- femur bone density over two centuries.
- Matched to the tissue matrix The density of the tissue matrix in the skin has implications for dermal fillers.
- A superior mattress with firm, high density hollow fiber polyester filling, to maintain high performance.
- For the most popular artifacts such as ceramic color standards and neutral density filters, streamlined procedures give a fast turn-around.
- flux density A measure of the magnetic effect induced in a medium by an external field.
- flux density in arbitrary units.
- The distributions of the flux, area, peak flux density and lifetimes of the concentrations are determined.
- The company can also mold polyurethane foam to any density.
- Further, bone mineral density of the proximal femur, lateral spine, and distal forearm was studied after eight years.
- forearm bone mineral density were found according to past nutrient intakes.
- fucus plants and creepers were growing in stiff perpendicular lines, governed by the density of the element that generated them.
- A universe with nonzero size and finite energy density appears from a quantum fuzz.
- The density of ice is about 0.92 g cm and that of water is about 1.00 g cm at 0.
- galaxyfield should therefore also display an over density of star-forming galaxies which the SCUBA images reveal to be the case.