A hydrodynamic model of a submerged lenticular wave energy device     

G.P. Thomas  D.V. Evans 《Applied Ocean Research》1983,5(2):69-79

The wavemaking capability and energy absorbing characteristics of a single submerged body, constrained to move horizontally in a surge mode, are examined. The body possesses both a vertical axis of symmetry and a horizontal plane of symmetry and is ‘thin’ in the sense that the body draft is small compared to the length. The behaviour of a single body subject to a constraint being placed upon the amplitude of its displacement and the properties of an array of interacting identical devices are also discussed.  相似文献   

3,4-benzopyrene and perylene in mussels, Mytilus sp., from the Laguna Veneta,North-East Italy     

V.U. Fossato  C. Nasci  F. Dolci 《Marine environmental research》1979,2(1):47-53

From July, 1975 to November, 1976 mussels from the Laguna Veneta, north-east Italy, and the adjacent Adriatic Sea were collected bimonthly at ten stations and analysed for 3,4-benzopyrene (BaP) and perylene (Pe) content. Mean concentrations were in the range 12·0–135·1 μg/kg dry weight for BaP and 1·5–16·9 μg/kg for Pe, but values as high as 327 μg/kg for BaP and 71 μg/kg for Pe have been measured. The distribution of BaP and Pe closely matches previous results on petroleum hydrocarbon contamination in mussels from this area and indicates that the major portion of BaP and Pe in these bivalves is due principally to human activities.  相似文献   

Dispersal patterns of clay minerals in the sediments of the eastern Mediterranean Sea     

K. VenkatarathnamWilliam B.F. Ryan 《Marine Geology》1971

A semiquantitative X-ray diffraction study of the finer-than-2μ-size fraction of the surface sediments of the eastern Mediterranean Sea has been carried out. On the basis of the abundances and the distributional patterns of the different clay minerals six mineral assemblages are distinguished. These assemblages have distinctive sources and their dispersal reflects different agents of transport in the eastern Mediterranean Sea.  相似文献   

The biochemical composition of the cypris larva of the barnacle Balanus balanoides L     

Holland  D. L.; Walker  G. 《ICES Journal of Marine Science》1975,36(2):162-165

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Benthic Metabolism and Standing Stock in the Central and Northern Deep Red Sea     

H. Thiel    O. Pfannkuche    R. Theeg  G. Schriever 《Marine Ecology》1987,8(1):1-20

Abstract. Benthic metabolism and standing stocks were investigated in the deep Red Sea between 21^o and 27^oN, Activity was assessed by the determination of respiration rates with a shipboard method and by calculating oxygen consumption from the activity in the electron transport system. We attempted to compare results from different latitudes within the warm Red Sea and with data from cold Atlantic environments. Our investigations were part of an environmental risk assessment to evaluate future mining of metalliferous sediments from the Atlantis II Deep.  相似文献   

Influence of structural flexibility and wave interference on dynamic behavior of idealized offshore platform     

A.G. Abul-Azm  A.N. Williams  S.T. Mau 《Ocean Engineering》1987,14(3)

An approximate method is presented to estimate the hydrodynamic loading and structural response of an idealized offshore platform subjected to a regular train of linear surface waves. The platform is taken to consist of four bottom-mounted, flexible, circular cylinders supporting a rigid deck and is assumed to be aligned parallel to the incident wave direction. The response of each column is assumed to be one-dimensional and to be governed by linear beam theory. The solution technique for the fluid velocity potential involves replacing scattered waves by equivalent plane waves together with non-planar, first-correction terms, and can be shown to be a large spacing approximation.Numerical results are presented which show the effect of hydrodynamic interference and structural flexibility on the platform response.  相似文献   

The pH measurements in seawater on the NBS scale     

Fiz F Perez  F Fraga 《Marine Chemistry》1987,21(4)

A new standardization method for glass electrodes is proposed for pH measurements on the NBS scale. An expression is obtained to evaluate the apparent activity coefficient of hydrogen ions as a function of salinity and temperature, from determinations obtained by Mehrbach et al., 1973 (Limnol. Oceanogr., 18: 897–907). This expression must be used to estimate systematic errors produced by variations of residual liquid-junction potential by estimating the apparent activity coefficient of hydrogen ions. In this way, values of pH obtained in oceanographical cruises can be standardized in order to determine and compare different parameters of the CO₂ system.Some experiments to study the variation of pH with temperature are carried out to compare the different series of acid constants used at present. A simple and precise polynomial equation is also obtained to determine the variation of pH with temperature.  相似文献   

Formation of chemogenic calcite in super-anoxic seawater — Framvaren, southern Norway     

Leif G. Anderson  David Dyrssen  Jens Skei   《Marine Chemistry》1987,20(4)

Framvaren, a super-anoxic fjord in southern Norway, contains 7–8 mmoll⁻¹ of sulphide and a total carbonate concentration of 18.5 mmol kg⁻¹ in the bottom water. The chemistry of calcium has been studied, considering sources, biogenic and chemical processes and sedimentary sinks. Calcium associated with the bacteria biomass at the redox interface (18m depth) appears to be the primary source of dissolved calcium in the deep, anoxic water. Excess calcium and high total carbonate cause supersaturation of calcite, which is precipitated chemogenically. Calcite (and presumably some aragonite) is identified both in sediment trap material and the bottom sediments below the depth of supersaturation.  相似文献   

Gravity anomalies over inactive fracture zones in the central North Atlantic     

Th. F. A. Mulder  B. J. Collette 《Marine Geophysical Researches》1984,6(4):383-394

The basement topography and the free-air gravity along two profiles in the central North Atlantic between 16° and 25° N, crossing a number of fracture zones, were divided in three wavelength intervals. Two-dimensional modelling shows that the short wavelength (>50 km) gravity is well explained by uncompensated topography (mainly spreading topography). For the long wavelengths (>200 km) there is no correlation of topography and gravity. In principle this topography is compensated. Residual anomalies comprise the Ridge effect as well as regional anomalies related to depth anomalies. The 50 to 200km band-pass filtered topography and gravity contain relevant information on fracture zones. Models require a base of the crust that parallels the topography rather than a form of regional compensation. For an explanation of this crustal model that has the appearance of frozen in normal faults we have to consider the typical morphology as created in the transform domain. The geophysical processes that cause this morphology are still an object of study.  相似文献   

On the analysis of catch and effort data   总被引：1，自引：0，他引：1  

Laurec  A; Shepherd  J. G. 《ICES Journal of Marine Science》1983,41(1):81-84

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