Stability of ion pairs from gypsum solubility degree of ion pair formation between the major constituents of seawater     

Bengt Elgquist  Margareta Wedborg 《Marine Chemistry》1975,3(3):215-225

The stability constants of the ion pairs NaSO₄^?, KSO₄^?, MgSO₄^?, CaSO₄, MgCl⁺ and CaCl⁺ were determined at 25°C and 0.7 M formal ionic strength, by measuring the solubility of gypsum (CaSO₄ · 2H₂O) in different media. The media used contained one or two of the following electrolytes: NaCl, KCl, MgCl₂, NaClO₄, Mg(ClO₄)₂, Na₂SO₄. Values for the stability constants are 1.22, 1.84, 12.3, 30.6, 0.48 and 1.20 M^?1, respectively, and the solubility product for gypsum is 2.87 · 10^?4M². The distribution of the main constituents of seawater was calculated using these results and the values of the carbonate and bicarbonate constants given by Dyrssen and Hansson (1972–1973). The solubility of gypsum in seawater as calculated and determined experimentally was 21.43 mM and 21.10 mM, respectively.  相似文献   

Insight into the nature of precipitation—Some achievements by T. Bergeron in retrospect     

Bengt Dahlström 《Pure and Applied Geophysics》1980,119(3):548-557

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The Evolution of Giant Oil Field Production Behavior     

Mikael Höök  Bengt Söderbergh  Kristofer Jakobsson  Kjell Aleklett 《Natural Resources Research》2009,18(1):39-56

The giant oil fields of the world are only a small fraction of the total number of fields, but their importance is huge. Over 50% of the world’s oil production came from giants by 2005 and more than half of the world’s ultimate reserves are found in giants. Based on this, it is reasonable to assume that the future development of the giant oil fields will have a significant impact on the world oil supply. In order to better understand the giant fields and their future behavior, one must first understand their history. This study has used a comprehensive database on giant oil fields in order to determine their typical parameters, such as the average decline rate and life-times of giants. The evolution of giant oil field behavior has been investigated to better understand future behavior. One conclusion is that new technology and production methods have generally led to high depletion rates and rapid decline. The historical trend points towards high decline rates of fields currently on plateau production. The peak production generally occurs before half the ultimate reserves have been produced in giant oil fields. A strong correlation between depletion-at-peak and average decline rate is also found, verifying that high depletion rate leads to rapid decline. Our result also implies that depletion analysis can be used to rule out unrealistic production expectations from a known reserve, or to connect an estimated production level to a needed reserve base.  相似文献   

Parallel electric fields accelerating ions and electrons in the same direction     

Bengt Hultqvist  Rickard Lundin 《Astrophysics and Space Science》1988,144(1-2):149-154

In this contribution we present Viking observations of electrons and positive ions which move upward along the magnetic field lines with energies of the same order of magnitude. We propose that both ions and electrons are accelerated by an electric field which has low-frequency temporal variations such that the ions experience an average electrostatic potential drop along the magnetic field lines whereas the upward streaming electrons are accelerated in periods of downward pointing electric field which is quasi-static for the electrons and forces them to beam out of the field region before the field changes direction.Paper dedicated to Professor Hannes Alfvén on the occasion of his 80th birthday, 30 May 1988.  相似文献