Articles by Author: J N Eloff

Search results for J N Eloff

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  1. Invloed van bewerking en besproeiing op die verwering van gneis in die Augrabies-gebied

    Invloed van bewerking en besproeiing op die verwering van gneis in die Augrabies-gebied

    Item type: Journal Article • Journal: South African Journal of Plant and Soil
    Fisiese, chemiese en mineralogiese kriteria is gebruik om te bepaal of veranderinge in eienskappe van gronde op gneise, in die Augrabies-gebied, as gevolg van bewerking en besproeiing plaasgevind het. Bewerking en besproeiing van die halfverweerde gneise het die verweringsproses versnel...
  2. THE ABSORPTION OF OXYGEN FROM LIQUID CULTURES OF BLUE-GREEN ALGAE BY ALKALINE PYROGALLOL

    THE ABSORPTION OF OXYGEN FROM LIQUID CULTURES OF BLUE-GREEN ALGAE BY ALKALINE PYROGALLOL

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    A mixture of pyrogallol with sodium hydroxide and sodium carbonate (2:1:1) in a separate container absorbed up to 75% of the oxygen in a bicarbonate-carbonate buffered medium with more or less no change in the pH of the medium. A...
  3. THE RELEASE OF NANNOCYTES DURING THE GROWTH CYCLE OF <underline>MICROCYSTIS</underline>

    THE RELEASE OF NANNOCYTES DURING THE GROWTH CYCLE OF <underline>MICROCYSTIS</underline>

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The change in nannocyte number during the growth of Microcystis under two light intensities (9,5 and 21 μEinsteins m−2 sec−1) over a period of 27 days were determined by a plating procedure. The nannocytes are released continuously over the growth...
  4. THE INFLUENCE OF LIGHT INTENSITY ON THE GROWTH OF DIFFERENT <underline>MICROCYSTIS</underline> ISOLATES

    THE INFLUENCE OF LIGHT INTENSITY ON THE GROWTH OF DIFFERENT <underline>MICROCYSTIS</underline> ISOLATES

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The influence of light intensity on the growth of seven Microcystis isolates was investigated using a batch culture system. The growth of Microcystis cultures was generally inhibited by light intensities higher than 10 μEinsteins m−2 sec−1. The optimal light intensity...
  5. THE EFFECT OF TEMPERATURE ON SPECIFIC GROWTH RATE AND ACTIVATION ENERGY OF MICROCYSTIS AND SYNECHOCOCCUS ISOLATES RELEVANT TO THE ONSET OF NATURAL BLOOMS

    THE EFFECT OF TEMPERATURE ON SPECIFIC GROWTH RATE AND ACTIVATION ENERGY OF MICROCYSTIS AND SYNECHOCOCCUS ISOLATES RELEVANT TO THE ONSET OF NATURAL BLOOMS

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    To investigate the correlation between temperature and the appearance of Microcystis blooms in nature, the effect of temperature on the growth of four Microcystis izolates (two toxic and two non-toxic) was investigated. The lower temperature limit for Microcystis varied between...
  6. THE EFFECT OF AGITATION AND TURBULENCE OF THE GROWTH MEDIUM ON THE GROWTH AND VIABILITY OF MICROCYSTIS

    THE EFFECT OF AGITATION AND TURBULENCE OF THE GROWTH MEDIUM ON THE GROWTH AND VIABILITY OF MICROCYSTIS

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Observation of natural blooms of Microcystis, suggested that increased turbulence plays a role in retarding bloom formation of Microcystis. In laboratory experiments the influence of turbulence mediated by a magnetic stirrer on the growth and viability of Microcystis in batch...
  7. MASS CULTURE OF <underline>MICROCYSTIS</underline> UNDER STERILE CONDITIONS

    MASS CULTURE OF <underline>MICROCYSTIS</underline> UNDER STERILE CONDITIONS

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The design and use of a 601 all-glass culture system for the mass production of Microcystis (or other unicellular algae) under sterile conditions, are described. Bleaching and lysis of the cells could be prevented by controlling the pH and CO2...
  8. CHEMICAL CHANGES IN THE GROWTH MEDIUM OF <em>MICROCYSTIS</em>, BATCH CULTURES GROWN AT STRESS AND NON-STRESS LIGHT INTENSITIES

    CHEMICAL CHANGES IN THE GROWTH MEDIUM OF <em>MICROCYSTIS</em>, BATCH CULTURES GROWN AT STRESS AND NON-STRESS LIGHT INTENSITIES

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    The modified BG 11 growth medium used in this study has a poor buffer ability and large pH changes occurred during growth of Microcystis. Inhibition of growth in cultures grown at stress light intensity (26 μEinst m−2 sec−1) could be...
  9. EFFECT OF PHOSPHATE CONCENTRATION ON THE FINE STRUCTURE OF THE CYANOBACTERIUM, <em>MICROCYSTIS AERUGINOSA</em> KÜTZ. EMEND. ELENKIN

    EFFECT OF PHOSPHATE CONCENTRATION ON THE FINE STRUCTURE OF THE CYANOBACTERIUM, <em>MICROCYSTIS AERUGINOSA</em> KÜTZ. EMEND. ELENKIN

    Item type: Journal Article • Journal: Journal of the Limnological Society of Southern Africa
    Microcystis aeruginosa toxic strain UV-006 stored a fixed amount of polyphosphate in spherical granules located in the centroplasm. Twenty four hours of phosphate starvation induced use of stored polyphosphate, manifested by reduction in granule numbers. Reintroduction of 2, 4 or...