Japanese Journal of Limnology (Rikusuigaku Zasshi)
Online ISSN : 1882-4897
Print ISSN : 0021-5104
ISSN-L : 0021-5104
Volume 32, Issue 4
Displaying 1-2 of 2 articles from this issue
  • Masami Nakanishi, F.J. Ward
    1971 Volume 32 Issue 4 Pages 85-89
    Published: December 31, 1971
    Released on J-STAGE: November 13, 2009
    JOURNAL FREE ACCESS
    Losses in primary productivity estimates caused by desiccation of filters ranged from 18 to 52% and were inversely related to the natural logarithms of light intensities during incubation. Losses caused by preservation were variable, depending on filter treatment and radioactivity counting method but were generally high in scintillation determinations. Significant fractions of total differences between primary productivity estimates from liquid scintillation counts of immediately filtered wet filters and Geiger-Müller counts of immediately filtered dry filters were associated with overestimating the relative activity of the carbon-14 stock solution (from 15 to 24%). In view of these and other causes for underestimating primary productivtiy, the 14C method requires further critical examination.
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  • Mikio Nagasawa
    1971 Volume 32 Issue 4 Pages 90-95
    Published: December 31, 1971
    Released on J-STAGE: November 13, 2009
    JOURNAL FREE ACCESS
    The high chloride groundwater in the Hokusetsu area, Osaka Prefecture was described. 1400 ppm of chloride was dissolved in the A group and 2000 ppm in the B group. These were the highest concentrations of over 740 investigations in the Eastern Osaka area. This high chloride groundwater was in one or more layers with aquifers of depths of 100m180m and it is assumed that they are present in the Osaka Group Upper Part. As the sample was composed of a water mixture from various layers, the salt concentration in a single layer is much higher. Both A and B groups are of the same origin and the groundwater was distributed in a rather wide range. The feature of the water quality is that it has low alkalinity, high chloride and contains significant amount of sulfate. Phosphorus content is low. Among cations, the content of sodium is high and that of calcium and magnesium is also high but their content is 1/11/2 of sodium. The water quality type is chloride type of 3 kinds of cations. The origin of this groundwater is sea water which has been sealed off at a certain period and remained stagnant, and the presence of sulfate is due to incomplete flushing out of saline water so low alkalinity was maintained in an environment of insufficient reduction of sulfate. The presence of large quaintities of magnesium and calcium can be explained by ion exchange between concentrated solution of the salt and clay minerals, adsorption and pricipitation.
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