Effect of free surface and strut on fins attached to a strut

An extensive experimental and computational investigation of the combined and separate effects of free surface and body on the lift characteristics of a pair of fins attached to a strut and fin alone is conducted. The results reveal that the free-surface effect becomes significant when the depth of submergence to chord ratio (H/c) is less than three. The effect of the strut is also realized for shallower depth of submergence of the fins through free-surface deformation leading to a significant change in the incidence angle of the flow to the fins. The numerical results based on the Higher Order Boundary Element Method with the linearized free-surface condition show good agreement with the experimental results for fin (foil) alone even at shallow submergence, but some discrepancies appear for the fin attached to the strut at higher speeds mostly due to the neglect of the nonlinear free-surface effect.     

Spectra of the Black-Sea tsunamis

We perform the analysis of the time spectra of four tsunamis generated in the Black Sea by the earthquakes of 26.07.1927, 11.09.1927, 26.12.1939, and 12.07.1966. For the analysis of the spectra, we used digitized marigrams obtained for 12 points of the Black-Sea coast. The obtained spectra are, as a rule, multimode and have 1–4 spectral maxima. One maximum corresponds to the periods typical of tsunami waves and the other maxima correspond to the oscillations of the sea level with lower frequencies. It seems likely that the events of tsunami are accompanied by low-frequency oscillations of the level caused by the atmospheric forcing, seiches, or other factors. In numerous cases, the oscillations from the predominant energy range lie outside the characteristic range of periods of the tsunami waves. __________ Translated from Morskoi Gidrofizicheskii Zhurnal, No. 5, pp. 21–30, September–October, 2007.     

Preservation of enzymic activity in marine plankton by low-temperature freezing

The measurement of enzymic activity in plankton communities is useful in the study of marine ecosystems. Such measurements can lead to a clearer understanding of the biological transformations in plankton communities at a particular time. However, the assays are somewhat time-consuming. To facilitate analysis of large numbers of samples, we have developed a method of quick-freezing of whole cells and of cell-free extracts of the diatom, Skeletonema costatum, followed by storage at ?60°C for up to one week. No loss in either the electron transport system (ETS) or the glutamate dehydrogenase (GDH) activity occurs. Similar conditions of storage can be used for the preservation of ETS activity in the marine copepod Calanus pacificus. Also, no measurable loss in either the GDH or the ETS activity is detectable after the quick-frozen whole cells of S. costatum have been kept frozen for over a year.     

Coulometric total carbon dioxide analysis for marine studies: maximizing the performance of an automated gas extraction system and coulometric detector

A global survey of the distribution of dissolved CO₂ taking advantage of sampling opportunities provided by the World Ocean Circulation Experiment: World Hydrographic Program (WOCE-WHP) is being carried out through 1995. Goals include the measurement of oceanic inorganic carbon transport and the development of a data base from which future fossil-fuel CO₂ build-up can be monitored. The analytical method selected for total carbon dioxide (C_T) is gas extraction of acidified seawater with coulometric titration of the acid formed by the resultant carbon dioxide and monoethanolamine. To combine high accuracy and precision (± 1.5 μmol/kg for C_T ≥ 2000 μmol/kg) with a high rate of analysis, we have modified an automated single-parameter system. Following prototype development between 1987 and 1990, an instrument emerged with the acronym Somma standing for single-operator multiparameter metabolic analyzer. Improved functional and operating procedures have integrated electronic calibration, CO₂ gas calibration, and sample analysis with automated pressure, temperature, and conductivity (salinity) sensing into a single convenient transportable package.     

The hydrogen sulphide boundary in the Black Sea in the 1920s and 1980s

Maps of the boundary topography for anaerobic waters in the Black Sea are plotted for the summers of the 1920s and 1980s. The mean depths of the H₂S boundary for this period are determined. It is shown that the variation in the distribution and average location of the hydrogen sulphide zone has remained constant for the last 60 years.Translated by Mikhail M. Trufanov.     

Spectral-temporal structure of variations in the atmospheric total ozone in central Eurasia

The results of long-term (1980–2003) systematic measurements of the total ozone content at the Issyk Kul station (42.6° N, 77.0° E; 1650 m above sea level) are presented. The statistical characteristics and spectral structure of variations in the total ozone and the main tendencies of its temporal variability are determined. It is found that the total ozone content decreased in 1980–2003 at an average rate of (?1.29±0.08) DU/yr. The results of Fourier and wavelet analyses have shown that only oscillations with periods of 12, 27–29, and 102–105 months are rather stable and can be represented as harmonic oscillations. Oscillations with periods shorter than six months have the character of periodically arising pulsations. Among these, oscillations with periods of 27–29 and 34–37 days can be distinguished. It is noted that the spectral-temporal structure of variations in the total ozone content obtained from ground-based measurements at the Issyk Kul station is in good agreement with the corresponding structure obtained from TOMS satellite measurements.     

A detailed survey near Mount Eratosthenes Eastern Mediterranean

A detailed marine survey made to the South West of Mount Eratosthenes is described. The results show the existence of a narrow zone of WNW trending deformed sediment west of the mount surrounded by an evaporite sequence in different stages of deformation.This work was intended to settle the conflict between the results of three previous interpretations of the tectonic structure of this area. We see the area being characterised by five areas with different degrees of tectonic deformation yet showing little causal relationship to overburden of Nile Cone sediments. A fault controlled cliff coincides with the previously described salt wall and strike slip fault yet we see no evidence for its diapiric origin nor positive evidence for strike slip motion along it. We concur with the previously observed area of higher free-air gravity anomalies termed the Eratosthenes tectonic zone, although it is traversed by several boundaries between areas of different deformation. Our results thus show some agreements and some re-interpretations of the observations. This complicated region is not yet fully understood however.     

Adaptive balance of global development processes

We study the processes of global self-regulation of Earth’s biota (GAIA-theory) by applying the method of adaptive balance of causes proposed by the authors. By using, as an example, the Daisy World model constructed by this method, we reveal the phenomenon of preservation of the mean temperature of Earth’s surface due to the presence of the vegetation cover. We develop an integral model of global natural, social, and economic processes in which the World Ocean is one of the factors regulating the amount of greenhouse gases in the atmosphere. The decrease in the amount of greenhouse gases in the atmosphere caused by the GAIA-effects increases the number of hurricanes and floods on the Earth. As a result, the levels of ecological and social hazards for the mankind become much higher. To eliminate these threats, it is necessary to intensify the processes of self-organization of the society realized via the improvement of education, development of science, and global regulation of the competition for natural resources. We present the results of numerical experiments performed by using the model demonstrating possible scenarios of global development with regard for the processes of self-organization of the society. __________ Translated From Morskoi Gidrofizicheskii Zhurnal, No. 3, Pp. 62–80, May–June, 2007.