Experiments on the production of a highly dispersible calcium carbonate. ('Experimental section' only) [Translation from: Szklo i Ceramiki 30, 133-136, 1979]

This short translation summarises experiments on the production of a highly dispersible precipitate of calcium carbonate. The translation covers the 'Experimental section' (of the original larger paper) only.

Effect of analytical conditions in wavelength dispersive electron microprobe analysis on the measurement of strontium-to-calcium (Sr/Ca) ratios in otoliths of anadromous salmonids

The use of strontium-to-calcium (Sr/Ca) ratios in otoliths is becoming a standard method to describe life history type and the chronology of migrations between freshwater and seawater habitats in teleosts (e.g. Kalish, 1990; Radtke et al., 1990; Secor, 1992; Rieman et al., 1994; Radtke, 1995; Limburg, 1995; Tzeng et al. 1997; Volk et al., 2000; Zimmerman, 2000; Zimmerman and Reeves, 2000, 2002). This method provides critical information concerning the relationship and ecology of species exhibiting phenotypic variation in migratory behavior (Kalish, 1990; Secor, 1999). Methods and procedures, however, vary among laboratories because a standard method or protocol for measurement of Sr in otoliths does not exist. In this note, we examine the variations in analytical conditions in an effort to increase precision of Sr/Ca measurements. From these findings we argue that precision can be maximized with higher beam current (although there is specimen damage) than previously recommended by Gunn et al. (1992).

Quantifying global terrestrial carbon influx and storage as stimulated by an increase in atmospheric carbon dioxide concentration

EXTRACT (SEE PDF FOR FULL ABSTRACT): Measurements of spatial and temporal distributions of carbon dioxide concentration and carbon-13/carbon-12 ratio in the atmosphere suggest a strong biospheric carbon sink in terrestrial ecosystems. Quantifying the sink, however, has become an enormous challenge for Earth system scientists because of great uncertainties associated with biological variation and environmental heterogeneity in the ecosystems. This paper presents an approach that uses two driving parameters to bound terrestrial carbon sequestration associated with an increase in carbon dioxide concentration.

Hydrological studies of Matatilla Reservoir, Uttar Pradesh

Matatilla Reservoir, located in semi arid region, (Lat. 25 degree 15'N and Long. 78 degree 23'E) has an area (at FRL) of 13,893 ha, volume and shore development 0.663 and 1.65, shoreline 73.6 km. Volume and shore development indicate that greater part of the reservoir is shallow, which is a favourable point for fish productivity. Temperature and dissolved oxygen gradually decreased with the increase in depth. Carbon dioxide was absent from the surface but invariably present in the bottom (3.6 ppm) pH remained alkaline (7.2-8.4 ppm) throughout the year. Alkalinity, chloride, calcium, magnesium, hardness and priductivity was maximum in pre-monsoon and minimum in monsoon except for calcium and manganesium in post-monsoon. Phosphate, nitrogen and ammonical nitrogen were found in traces. These variations may be due to influx and outflow of water and use of reservoir water for multipurpose activities.

Embankment damaging marine organisms and their control measures using calcium carbide

Five species of crabs and three species of fishes were the main marine organisms found damaging embankments owing to their burrowing nature. Among crabs, Scylla serrata was in the highest percentage, while among fishes, Boleopthalamus dussumieri was recorded in maximum percentage calcium carbide 10-15 per burrow was effective in eradicating the crabs.

Enrichment of rotifer Brachionus rotundiformis with calcium

Possibility of enrichment of rotifer (Brachionus rotondiformis) with calcium (Ca) for feeding the fish fry was investigated. Rotifer was kept for 24 h with aeration in normal seawater (Treatment 1), seawater with 400 mg/l supplemental Ca from Ca-lactate (Treatment 2) and seawater with 400 mg/l supplemental Ca from Ca-chloride (Treatment 3). After the experimental period, Ca contents of rotifer were 0.20, 0.29 and 0.39% of dry weight in T-1, T-2 and T-3, respectively. Ca content of media did not affect phosphorus, zinc and manganese contents of rotifer. Results revealed that rotifer can be enriched with Ca for feeding fish fry and Ca-chloride might be a better source for Ca enrichment.

Necessity of dietary calcium supplement in file fish (Monacanthus cirrhifer)

File fish, Monacanthus cirrhifer, juveniles with initial mean body weight of 0.27g were fed purified diets with or without calcium (Ca) supplement for 10 weeks at a water temperature of 27.0±1.4°C. Growth was significantly low in fish fed diet without Ca supplement than fish fed diet with Ca supplement. Feed efficiency and condition of fish were also significantly decreased in absence of a dietary Ca supplementation, Minerals contents of bone were similar in both the treatment groups and did not appear as a suitable indicator of Ca requirement. It appeared that Ca supplement to the purified diet is necessary for file fish for their proper growth and feed utilization.