On the tides at the port of London

1837 ◽  
Vol 3 ◽  
pp. 399-400
Keyword(s):  
Atmospheric Pressure ◽  
High Water ◽  
The Moon ◽  
Mean Time

The discussions of tide observations which the author has hitherto at various times laid before the Society, were instituted with reference to the transit of the Moon immediately preceding the time of high-water; from which the laws of the variation in the interval between the moon’s transit and the time of high-water have been deduced. But the discussion of nineteen years’ observations of the tides at the London Docks, which is given in the present paper, has been made with reference to the moon’s transit two days previously, and proves very satisfactorily that the laws to which the phenomena are subject accord generally with the views propounded long since by Bernouilli, The relations which the author points out between the height of high-water and the atmospheric pressure as indicated by the barometer are particularly interesting and important. The influence of the wind is also considered; and such corrections indicated as are requisite in consequence of the employment by several observers of solar instead of mean time.

scholarly journals XV. The Bakerian lecture.—On the tides at the port of London

1836 ◽  
Vol 126 ◽  
pp. 217-266 ◽  
Keyword(s):  
High Water ◽  
The Moon ◽  
The Law

The discussions of tide observations which I have had the honour to lay before the Society on different occasions, have been instituted with reference to the transit of the moon immediately preceding the time of high water. The Tables which I have thus prepared for London and Liverpool, in order to serve for predicting the phenomena, answer the purpose for which they were intended, and may also afford some notions with respect to the laws of the phenomena, and to the degree of accuracy of which the inquiry is susceptible, impeded by the rude manner in which the observations are made, and by accidents. But when the discussion is instituted with reference to the transit immediately preceding the time of high water, the law of the variations in the interval between the moon’s transit and the time of high water is obscured. The discussion of nineteen years’ observations of tides at the London Docks, which I now offer, has been made with reference to the moon’s transit two days previous, and will, I trust, be viewed with interest, for it proves that the laws to which the phenomena are subject accord generally with the views propounded long since by Bernoulli.

XXV. Note on the tides in the port of London

1832 ◽  
Vol 122 ◽  
pp. 595-599 ◽  
Keyword(s):  
Great Britain ◽  
A Priori ◽  
High Water ◽  
Eastern Coast ◽  
The Moon ◽  
Cape Of Good Hope ◽  
The Difference

Mr. Stratford has favoured me with a comparison of the predicted times of high water deduced from Mr. Bulpit’s Tables, White’s Ephemeris, and the British Almanac, with the observations at the London Docks. These observations are, unfortunately, so imperfect, that the differences must not be entirely attributed to the errors of the Tables, which, however, seem susceptible of much improvement. I subjoin this comparison; and in order to convey an idea of the confidence which may be placed in the observations, I also subjoin a comparison, by Mr. Deacon, of the observations at the London and St. Katherine’s Docks, which are made according to the same plan, and of which the merit is the same. The differences in the determinations at these two places, which are only about a quarter of a mile distant from each other, may serve to indicate the reliance which can be placed in either. In my paper on the Tides at Brest, I remarked that the retard or the constant λ — λ, is considerably greater as deduced from observation here than at Brest. That this must be the case is also evident from the following very simple à priori considerations.—The highest high water takes place when the moon passes the meridian at a time equal to the retard. The tide is propagated from Brest to London, round Scotland, in about twenty-two hours, that is, supposing the tide which takes place in our river to be principally due to that branch of the tide which descends along the eastern coast of Great Britain, which I believe to be the case. The highest tide therefore is propagated from Brest to London in about twenty-two hours, and the difference in the retard or in the constant λ — λ, will be nearly the moon’s motion in twenty-two hours, or about 11°; I made the difference in the retard from observation 10°. The tide takes about fifteen hours to reach Brest from the Cape of Good Hope; no doubt the retard there is considerably less.

scholarly journals Lunisolar Atmospheric Tides. II

1989 ◽  
Vol 42 (4) ◽  
pp. 439 ◽  
Author(s):  
R Brahde
Keyword(s):  
Phase Shift ◽  
Atmospheric Pressure ◽  
Mean Amplitude ◽  
Atmospheric Tides ◽  
The Moon ◽  
Celestial Equator

In an earlier paper (Brahde 1988) it was shown that series of measurements of the atmospheric pressure in Oslo contained information about a one�day oscillation with mean amplitude 0�17 mb. The data consisted of measurements every second hour during the years 1957-67, 1969 and 1977. In the present paper the intervening years plus 1978 and 1979 have been included, increasing the basis from 13 to 23 years. In addition the phase shift occurring when the Moon crosses the celestial equator has been defined precisely, thus making it possible to include all the data.

I. Dynamical considerations - Dynamics of the Moon

1967 ◽  
Vol 296 (1446) ◽  
pp. 245-247 ◽  
Keyword(s):  
Atmospheric Pressure ◽  
Uniform Density ◽  
The Moon ◽  
Homogeneous Body ◽  
Cubic Form ◽  
The Earth ◽  
Change Of State ◽  
Rate Of Increase ◽  
The Mean ◽  
Single Material

We know the mass of the Moon very well from the amount it pulls the Earth about in the course of a month; this is measured by the resulting apparent displacements of an asteroid when it is near us. Combining this with the radius shows that the mean density is close to 3.33 g/cm 3 . The velocities of earthquake waves at depths of 30 km or so are too high for common surface rocks but agree with dunite, a rock composed mainly of olivine (Mg, Fe II ) 2 SiO 4 . This has a density of about 3.27 at ordinary pressures. The veloci­ties increase with depth, the rate of increase being apparently a maximum at depth about 0.055 R in Europe and 0.075 R in Japan. It appeared at one time that there was a discontinuity in the velocities at that depth, corresponding to a transition of olivine from a rhombic to a cubic form under pressure. It now seems that the transition, though rapid, is continuous, presumably owing to impurities, but the main point is that the facts are explained by a change of state, and that the pressure at the relevant depth is reached nowhere in the Moon, on account of its smaller size. There will, however, be some compression, and we can work out how much it would be if the Moon is made of a single material. It turns out that the actual mean density of the Moon would be matched if the density at atmospheric pressure is 3.27—just agreeing with the specimen of dunite originally used for comparison. The density at the centre would be 3.41. Thus for most purposes the Moon can be treated as of uniform density. With a few small corrections the ratio 3 C /2 Ma 2 would be 0.5956 ± 0.0010, as against 0.6 for a homogeneous body. To make it appreciably less would require a much greater thickness of lighter surface rocks than in the Earth.

The Natural Vacuum Desalination Technology in Seawater Desalination

2014 ◽  
Vol 675-677 ◽  
pp. 851-855 ◽  
Author(s):  
Xiao Hua Liu ◽  
Xin Chun Zhang ◽  
Ya Qin Fang ◽  
Ming Ming Zhu
Keyword(s):  
Low Temperature ◽  
Water Column ◽  
Physical Model ◽  
Future Development ◽  
Atmospheric Pressure ◽  
High Water ◽  
Seawater Desalination ◽  
Different Types ◽  
Desalination Technology

Seawater desalination technology is an important way to solve the freshwater shortage problem. Natural vacuum desalination (NVD) technology generates very low pressure environment in the headspace of 10 meters high water column. The weight of the water column is balanced by atmospheric pressure, and low-temperature desalination proceeds in the headspace. NVD technology drives the desalination process without any mechanical pumping, and requires relatively inferior quality of device material and simple structures. In this paper, the basic theory of NVD technology is introduced and physical model is described. Research progresses of different types of NVD technologies are summarized, and the method of increasing freshwater production is pointed out. This paper also illustrates the outlook on future development of NVD technology.

scholarly journals On the results of tide observations, made in June 1834, at the Coast-Guard stations in Great Britain and Ireland

1837 ◽  
Vol 3 ◽  
pp. 329-330
Keyword(s):  
High Water ◽  
Coast Guard ◽  
Maximum Magnitude ◽  
The Moon ◽  
Diurnal Difference ◽  
Exact Determination ◽  
The Subject ◽  
The Times ◽  
Two Sides ◽  
Made In

On a representation made by the author of the advantages which would result from a series of simultaneous observations of the tides, continued for a fortnight, along a great extent of coast, orders were given for carrying this measure into effect at all the stations of the Preventive service on the coasts of England, Scotland, and Ireland, from the 7th to the 22nd of June inclusive. From an examination of the registers of these observations, which were transmitted to the Admiralty, but part of which only have as yet been reduced, the author has been enabled to deduce many important inferences. He finds, in the first place, that the tides in question are not affected by any general irregularity, having its origin in a distant source, but only by such causes as are merely local, and that therefore the tides admit of exact determination, with the aid of local meteorological corrections. The curves expressing the times of high water, with relation to those of the moon’s transit, present a very satisfactory agreement with theory; the ordinates having, for a space corresponding to a fortnight, a minimum and maximum magnitude, though not symmetrical in their curvatures on the two sides of these extreme magnitudes. The amount of flexure is not the same at different places; thus confirming the result already obtained by the comparison of previous observations, and especially those made at Brest; and demonstrating the futility of all attempts to deduce the mass of the moon from the phenomena of the tides, or to correct the tables of the tides by means of the mass of the moon. By the introduction of a local, in addition to the general, semimenstrual inequality, we may succeed in reconciling the discrepancies of the curve which represents this inequality for different places; discrepancies which have hitherto been a source of much perplexity. These differences in the semimenstrual inequality are shown by the author to be consequences of peculiar local circumstances, such as the particular form of the coast, the distance which the tide wave has travelled over, and the meeting of tides proceeding in different directions; and he traces the influence of each of these several causes in producing these differences. A diurnal difference in the height of the tides manifests itself with remarkable constancy along a large portion of the coast under consideration. The tide hour appears to vary rapidly in rounding the main promontories of the coast, and very slowly in passing along the shores of the intervening bays; so that the cotidal lines are brought close together in the former cases, and, in the latter, run along nearly parallel to the shore; circumstances which will also account for comparative differences of level, and of corresponding velocities in the tide stream. The author intends to prosecute the subject when the whole of the returns of these observations shall have undergone reduction.

scholarly journals Welt Mechanik

1837 ◽  
Vol 3 ◽  
pp. 413-413
Keyword(s):  
Elliptical Orbit ◽  
The Moon ◽  
Universal Gravitation ◽  
The Earth ◽  
Detailed Exposition ◽  
The Difference ◽  
Mean Time ◽  
New Hypothesis

The object which the author has in view, in this paper, is to over­turn the theory of universal gravitation, as regulating the planetary motions. The memoir is divided into two parts ; in the first, he dis­putes the accuracy of Kepler’s law respecting the description of equal areas in equal times, and endeavours to confute the funda­mental doctrines of astronomy relating to the elliptical orbit of the earth, the difference between solar and mean time, and the whole theory of the motions of the moon and the planets. In the second part, the author enters into a detailed exposition of his own views of the mechanism of the heavens ; and devotes 215 closely' written pages to the development of a perfectly new hypothesis, which he advances, founded on a supposed variation of the progressive mo­tion of the planets, in an orbit perfectly circular, and by which he thinks he can explain all the phenomena they present to observa­tion.

The vaporization behavior of carbon and hydrogen from the early global magma ocean

2021 ◽  
Author(s):  
Natalia Solomatova ◽  
Razvan Caracas
Keyword(s):  
First Principles ◽  
Atmospheric Pressure ◽  
Considerable Effect ◽  
Early Earth ◽  
The Moon ◽  
Magma Ocean ◽  
Cooling History ◽  
History Of ◽  
Carbon Molecules ◽  
Dense Atmosphere

<p>Estimating the fluxes and speciation of volatiles during the existence of a global magma ocean is fundamental for understanding the cooling history of the early Earth and for quantifying the volatile budget of the present day. Using first-principles molecular dynamics, we predict the vaporization rate of carbon and hydrogen at the interface between the magma ocean and the hot dense atmosphere, just after the Moon-forming impact. The concentration of carbon and the oxidation state of the melts affect the speciation of the vaporized carbon molecules (e.g., the ratio of carbon dioxide to carbon monoxide), but do not appear to affect the overall volatility of carbon. We find that carbon is rapidly devolatilized even under pressure, while hydrogen remains mostly dissolved in the melt during the devolatilization process of carbon. Thus, in the early stages of the global magma ocean, significantly more carbon than hydrogen would have been released into the atmosphere, and it is only after the atmospheric pressure decreased, that much of the hydrogen devolatilized from the melt. At temperatures of 5000 K (and above), we predict that bubbles in the magma ocean contained a significant fraction of silicate vapor, increasing with decreasing depths with the growth of the bubbles, affecting the transport and rheological properties of the magma ocean. As the temperature cooled, the silicate species condensed back into the magma ocean, leaving highly volatile atmophile species, such as CO<sub>2</sub> and H<sub>2</sub>O, as the dominant species in the atmosphere. Due to the greenhouse nature of CO<sub>2</sub>, its concentration in the atmosphere would have had a considerable effect on the cooling rate of the early Earth.</p>

Mussel-inspired modification of a polymer membrane for ultra-high water permeability and oil-in-water emulsion separation

2014 ◽  
Vol 2 (26) ◽  
pp. 10225-10230 ◽  
Author(s):  
Hao-Cheng Yang ◽  
Kun-Jian Liao ◽  
He Huang ◽  
Qing-Yun Wu ◽  
Ling-Shu Wan ◽  
...  
Keyword(s):  
Water Permeability ◽  
Atmospheric Pressure ◽  
High Water ◽  
Polymer Membrane ◽  
Water Emulsion ◽  
Surface Hydrophilicity ◽  
Oil In Water ◽  
Emulsion Separation ◽  
Oil Water ◽  
Oil In Water Emulsion

Polydopamine/polyethyleneimine-decorated membranes were fabricated with excellent surface hydrophilicity and high water permeability for oil/water emulsion separation under atmospheric pressure.

IX.—The Lunar Atmospheric Pressure Inequalities at Glasgow

1936 ◽  
Vol 55 ◽  
pp. 91-96
Author(s):  
R. A. Robb ◽  
T. R. Tannahill
Keyword(s):  
Atmospheric Pressure ◽  
The Moon

In several papers by Chapman (1918, p. 271; 1919, p. 113, etc.) the effect of the moon on the atmospheric pressure has been analysed; the chief inequality observed is semi-diurnal, being, for example, 0·0120 sin (2θ+ 114°) millibar at Greenwich, 0·083 sin (2θ+ 68°) millibar at Batavia, and 0·060 sin (2θ+ 60°) millibar at Hongkong;θbeing measured from upper lunar transit.

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