Low‐frequency acoustics of bubble plumes formed in fresh water and salt water

2000 ◽  
Vol 108 (5) ◽  
pp. 2545-2545
Author(s):  
Thomas K. Berger ◽  
Michael J. Buckingham
1772 ◽  
Vol 62 ◽  
pp. 90-92 ◽  
Keyword(s):  

The materials necessary for this process are the following; a copper or iron pot of 15 or 20 gallons, an empty cask, some sheet lead, a small jar, a few wood-ashes or soap, and billet-wood for fewel.


2010 ◽  
Vol 66 (2) ◽  
pp. 189-195
Author(s):  
Yuji ITO ◽  
Hideki MIYAMOTO ◽  
Masumi KORIYAMA ◽  
Jiro CHIKUSHI ◽  
Masahiro SEGUCHI

1964 ◽  
Vol 90 (6) ◽  
pp. 97-116
Author(s):  
Norbert L. Ackermann ◽  
Pachern Sridurongkatum

Geophysics ◽  
2021 ◽  
pp. 1-68
Author(s):  
John W. Neese ◽  
David R. Jackson ◽  
Yingcai Zheng ◽  
Leon A. Thomsen

Electromagnetic tunnel detection is studied numerically using a 3D analytic infinite lossy homogeneous space solution to magnetic dipole radiation and scattering from an infinite cylinder, in a crosshole context. At low frequencies this serves as a model for a transmit coil radiating a time-varying magnetic field that is then detected from the open-circuit voltage induced on a receive coil. Numerical simulations illustrate how various parameters influence the signal strength and the ability to discern the scattered signal. Tunnel detection is achieved at relatively high frequencies (but below typical GPR frequencies) for fresh water saturated sand and for weathered granite, which are lower loss media; for the coil and tunnel parameters used here, optimum frequencies appear to be between 100 kHz and 1 MHz. Tunnel detection for fresh water saturated clay, a much more lossy medium, can be achieved at a quite low frequency, with an optimum frequency between 1 and 10 kHz. These results suggest that, when a resonant coil system is employed, tunnel detection may be possible in a wider range of earth media than previously reported, when the best-suited choice of frequency is employed.


1968 ◽  
Vol 8 (33) ◽  
pp. 491 ◽  
Author(s):  
RW Strickland

A pot trial to assess the effect of salt water on growth and yield of rice in the Northern Territory of Australia was conducted in 1962-63. Two varieties were irrigated with three levels of salinity for varied durations in either the establishment or reproductive phases. Plant emergence was significantly depressed by soil conductivities in excess of 4 m-mhos/cm at 25�C. The restricted use of up to 3000 p.p.m. total soluble salts from 10 days after emergence and of up to 6000 p.p.m. from 20 days after emergence, followed by fresh water, had no effect on flowering time, vegetative or grain yields. The application of 3000 and 6000 p.p.m. total soluble salts in the reproductive phase reduced mean panicle number and grain yield of both varieties and straw yield of one variety. Use of saline water in the establishment phase followed by fresh water and drainage, reduced soil conductivity. In the reproductive phase it nullified the effect of previous fresh water flushing and tended to increase soil conductivity above original levels.


Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2033
Author(s):  
Jonathan Phillips ◽  
Alexander Roman

As predicted by the theory of super dielectric materials, simple tests demonstrate that dielectric material on the outside of a parallel plate capacitor dramatically increases capacitance, energy density, and power density. Simple parallel plate capacitors with only ambient air between the plates behaved as per standard theory. Once the same capacitor was partially submerged in deionized water (DI), or DI with low dissolved NaCl concentrations, still with only ambient air between the electrodes, the capacitance, energy density, and power density, at low frequency, increased by more than seven orders of magnitude. Notably, conventional theory precludes the possibility that material outside the volume between the plates will in any fashion impact capacitive behavior.


1960 ◽  
Vol 17 (3) ◽  
pp. 295-322 ◽  
Author(s):  
Bertha Baggerman

In juvenile Pacific salmon the changes in salinity preference associated with seaward migration and thyroid activity were studied and used as criteria for the induction of the physiological condition required for migration (migration-disposition).Four species of Oncorhynchus (chum, pink, coho and sockeye) changed preference from fresh to salt water at the onset of seaward migration and maintained this preference throughout the migration season. At the end of this migration period coho and sockeye salmon changed preference from salt to fresh water if retained in fresh water, indicating a re-adaptation to this medium in which they may survive for several years. Chum and pink fry did not show this change in preference and usually died when retained in fresh water. They were apparently unable to re-adapt to this environment.The increasing day length in spring controls the time at which the change in preference from fresh to salt water takes place, and is thus involved in timing the induction of migration-disposition.The photoperiod seems to affect particularly the pituitary-thyroid system. Thyroid activity increases shortly before the onset of migration, remains high during the migration season, and decreases towards its end. The level of thyroid hormone in the blood influences salinity tolerance and preference and, thus, the induction of migration-disposition. Metamorphosis, osmotic "stress" and iodine content of the water may have some additional effect on thyroid activity, but are not the only factors responsible for thyroid hyperactivity during migration.Animals in which migration-disposition has been induced are thought to have become susceptible to appropriate external stimuli "releasing" migration.


Sign in / Sign up

Export Citation Format

Share Document