Measurements of high-frequency shallow-water acoustic phasefluctuations     

Stanic  S.J. Goodman  R.R. Meredith  R.W. Kennedy  E. 《Oceanic Engineering, IEEE Journal of》2000,25(4):507-515

A shallow-water high-frequency (HF) acoustic propagation experiment was conducted just off shore in Panama City, FL. Several broad-band high-resolution sources and receivers were mounted on stable platforms and deployed in water depths of 8-10 m. Signals covering the frequency range from 20 to 200 kHz were transmitted from the sources to two spatially separated receivers. The data were analyzed to provide estimates of the signal phase variances as a function of frequency and source-to-receiver range. These phase variabilities are correlated with small-scale water column thermal variabilities and ocean swell conditions  相似文献   

A stochastic interpretation of the tailing effect in solute transport     

C. A. Kennedy  W. C. Lennox 《Stochastic Environmental Research and Risk Assessment (SERRA)》2001,15(4):325-340

 The advection-dispersion equation (ADE) is inadequate for describing tails in solute breakthrough curves. Re-examination of solute breakthrough curves from one-dimensional experiments in porous media and channel flow literature shows a consistent discrepancy compared with solutions to the ADE. The leading tail of breakthrough curves is sharper, and the trailing tail is longer and smoother, than best fitting, least-squares ADE solutions. A random particle simulation exercise shows that the ADE may firstly be erroneous because of the assumption of time steps over which random solute movements are considered independent. Definition of such time steps hinges upon the slowest random movements, such as those predominantly by molecular diffusion. A second potential source of error is the highly skewed nature of the inverse distribution of underlying, micro-scale velocities, which causes slow convergence to normality under the central limit theorem.  相似文献   

Effect of salinity and temperature on survival and development of young zebra (Dreissena polymorpha) and quagga (Dreissena bugensis) mussels     

David A. Wright  Eileen M. Setzler-Hamilton  John A. Magee  Victor S. Kennedy  Stephen P. McIninch 《Estuaries and Coasts》1996,19(3):619-628

We reared larval zebra mussels,Dreissena polymorpha, and quagga mussels,D. bugensis, through and beyond metamorphosis (settlement) at salinities of 0–8‰. Juvenile zebra mussels gradually acclimated to 8‰ and 10‰ have been reared at these salinities for over 8 mo. Tolerance to both higher temperatures and higher salinities increases with larval age in both species (though zebra mussel embryos and larvae have a greater degree of salinity tolerance than quagga mussel embryos and larvae). Thus, only 6% of 3-day-old zebra mussel veligers survived after exposure to 4‰ for 8 additional days, whereas there was 22% survival of veligers placed in 4‰ at day 13 and grown to settlement 11 d later. Zebra mussel pediveligers, acclimated to increasing salinity in 2‰ increments beginning at day 23, continued to survive and grow in 8‰ after 5-mo exposure, though the growth rates of these juveniles were significantly less than those of juveniles reared in lower salinities. Quagga mussels did not metamorphose and settle as quickly as zebra mussel pediveligers. No quagga mussel pediveligers had settled before exposure to artificial fresh water (AFW), 2‰ 4‰, 6‰, and 8‰ on day 30. Percent settlement of these quagga mussel juveniles (based on 100% survival at the start of experiments on day 30) was 90% in AFW, 67% at 2‰, 69% at 4‰, 46% at 6‰, and 0.1% at 8‰.  相似文献   

Wetland functions and values: The state of our understanding     

Victor Kennedy 《Estuaries and Coasts》1981,4(4):388-388

  相似文献   

Progress in physical geography,Volume 1, Numbers 1 and 2, Edited by B. W. Atkinson,R. J. Chorley,D. R. Stoddard,C. Board,P. Haggett and D. Lowenthal,London, Edward Arnold, 1977. No. of pages: iv and 373     

Barbara A. Kennedy 《地球表面变化过程与地形》1978,3(4):431-432

  相似文献   

After horton     

Barbara A. Kennedy 《地球表面变化过程与地形》1978,3(3):219-231

The divergent and yet related problems of post-Hortonian studies of drainage density and channel network geometry are viewed against the difficulties of defining first-order channels and basins. It is proposed that the junction of an unbranched perennial (or blue-line) channel with another perennial channel be taken as the starting point for definitions and that the entire contour-crenulation network tributary to that point be considered the first-order stream. It is shown that the concept of network diameter may be used to describe the networks so delimited and that it appears to provide a useful starting point for interregional comparisons. Finally, an analysis of Blyth and Rodda's (1973) data on channel lengths and discharge indicates that network diameter may be as closely related to discharge as is channel length itself.  相似文献   

Kyanite eclogites     

Alexander A. Godovikov  George C. Kennedy 《Contributions to Mineralogy and Petrology》1968,19(2):169-176

Prior experimental work has shown that in the laboratory the mineralogy of eclogites is sensitive to the ratio of CaO ∶ MgO ∶ FeO and that the reaction pyroxene + kyanite?garnet + quartz proceeds to the right at high pressures in rocks rich in magnesium and to the left in rocks rich in calcium and iron. Typical basalts crystallized at high pressure never contain kyanite. The chemistry and mineralogy of a large number of naturally occurring eclogites show they belong to three classes.

1. Kyanite-free magmatic eclogites, rich in magnesium, from:
2. kimberlites
3. dunites and serpentinites.
4. Kyanite-bearing eclogites and grosspydites rich in CaO and low in FeO with intermediate MgO from:
5. kimberlites
6. gneisses.
7. Kyanite-free eclogites of metamorphic origin rich in iron with low magnesium and intermediate amounts of calcium from:
8. glaucophane schists
9. gneisses.

  相似文献   

A revision of the ammonite faunas of the type Cenomanian. i. Introduction,ancyloceratina     

W.J. Kennedy  P. Juignet 《Cretaceous Research》1983,4(1):3-83

This paper forms the first part of a revision of the ammonite faunas of the Cenomanian stratotype in the environs of Le Mans, Sarthe, France. The history of research on ammonites in the area is briefly noted, as is the lithostratigraphy. The systematics of the heteromorph ammonites (Ancyloceratina) is described, and the following taxa documented: Hamites simplex d'Orbigny, Sciponoceras baculoides (Mantell), Sciponoceras gracile (Shumard), Anisoceras plicatile (J. Sowerby), A. aff. plicatile, Idiohamites alternatus vectensis Spath, I. ellipticus radiatus Spath, Hypoturrilites gravesianus (d'Orbigny), H. tuberculatus (Bosc), H. mantelli (Sharpe), H. sp., Neostlingoceras carcitanense (Matheron), N. aff. carcitanense, Turrilites costatus Lamarck, T. acutus Passy, T. scheuchzerianus (Bosc), T. boerssumensis Schlüter, Mariella dorsetensis (Spath), M. cenomanensis (Schlüter), M. group of cenomanensis (Schlüter)-lewesiensis (Spath), M. spp., M. (Plesioturrilites) sp., Scaphites equalis J. Sowerby, S. obliquus J. Sowerby, S.(?) sp., and S. sp. juv.  相似文献   

The affinities of Codazziceras Etayo-Serna, 1979 (Cretaceous ammonoidea)     

C.W. Wright  G.R. Chancellor  W.J. Kennedy 《Cretaceous Research》1983,4(4):341-348

  相似文献   

Ammonites from the Pawpaw Shale (Upper Albian) in northeast Texas     

W.J. Kennedy 《Cretaceous Research》2004,25(6):865-905

The lower part of the Pawpaw Shale in northeast Texas yields an abundance of diminutive limonitic ammonites, the assemblage being: Tetragonites sp. juv., Engonoceras serpentinum (Cragin, 1900), Conlinites wrighti gen. et sp. nov., Cantabrigites wenoensis (Adkins, 1920), Neophlycticeras (Neophlycticeras) sp., Neophlycticeras (Paradolphia) occidentalis sp. nov., Stoliczkaia (Stoliczkaia) clavigera Neumayr, 1875, Stoliczkaia (Lamnayella) worthense (Adkins, 1920), Stoliczkaia (Shumarinaia) asiatica Matsumoto and Inoma, 1975, Enigmaticeras riceae gen. et sp. nov., Flickia simplex Pervinquière, 1907, Ficheuria pernoni Dubourdieu, 1953, Ficheuria americana sp. nov., Anisoceras armatum (J. Sowerby, 1817), Hamites venetzianus Pictet, 1847, Mariella (Mariella) worthensis (Adkins and Winton, 1920), Mariella (Mariella) asper sp. nov., Lechites (Lechites) comanchensis (Adkins, 1920), Worthoceras worthense (Adkins, 1920), and Scaphites hilli Adkins and Winton, 1920.This assemblage is correlated with the Mortoniceras (Subschloenbachia) rostratum Subzone of the European sequence on the basis of the occurrence of that species in the underlying Weno Limestone, in the passage beds between the Pawpaw Shale and the succeeding Main Street Limestone, and the lower part of the Main Street.Some previous authors have interpreted the diminutive limonitic ammonites of the Pawpaw as being “dwarf” or “stunted”. The overwhelming majority of individuals are nuclei of much larger ammonites, with smaller numbers of adults of small species that occur in other facies and geographic locations, together with a smaller number still of paedomorphic dwarfs. The fauna is interpreted as a preservational one, where diagenetic pyrite formed in relatively small voids, either the early phragmocone chambers of larger ammonites, or the phragmocone and body chambers of genuinely diminutive species which oxidised to limonite during the weathering process.  相似文献