Robust decisions in power system investments
The Turkish electrical system has been studied, particularly for the near term investment programme. The objective of the study was to determine the most likely investment alternatives for the next ten-year period, from a cost effectiveness point of view. A dynamic linear programming model was used in representing the national energy system, with special emphasis on the electricity sector. Hydro, coal, nuclear and oil-fired power plants as well as their interconnection investments were modelled. A 27-year planning horizon was defined. The scenario approach was utilized in establishing the effects of different factors, such as foreign currency requirements of projects, nuclear plant costs and nuclear fuel costs, demand growth rates for electricity as well as other fuels, availability of foreign currency and skilled manpower, and the development rates of coal mines, coal power plants and nuclear power plants. After analyzing the results of 24 different scenarios, robust plans for developing the power system are suggested. Other investments that are subject to the realization of certain conditions are also indicated.
Models for national energy policy analysis and planning
Two energy models have been developed that represent the national energy system. One of these is a 'fuel model' that includes only the major conversions and investments in the energy sector, covers a time span of 15 years and uses linear programming (LP) techniques. The other is an 'energy model' that includes the activities in the energy sector in considerable detail, covers a time span of 24 years, and uses mixed integer programming (MIP) formulation. The Fuel Model has been applied to Turkey for the years 1960-1975, while the 'Energy Model' has been used to analyze possible development for the years 1976-2000. Some of the results pertaining to the validation and analysis runs have been presented along with experiences in implementation of the models.
BIOSYNTHESIS OF DAUNORUBICIN GLYCOSIDES: ANALYSIS WITH BLOCKED MUTANTS
ABSTRACT Daunorubicin (daunomycin; NSC 82151) is an anthracycline antibiotic that is useful in the treatment of human leukemias. Several Streptomyces species accumulate higher glycosides of daunorubicin, which can be converted to daunorubicin by simple hydrolysis. We isolated a number of mutants of a daunorubicin glycoside-producing streptomycete, and found that some were deficient in accumulation of daunorubicin glycosides. One such mutant accumulated no detectable anthracyclines, while other mutants accumulated anthracyclines or aglycones that have not been reported before or have been described as co-metabolites of daunorubicin glycosides. Some of these anthracyclines and aglycones were purified and used as substrates in bioconversion experiments with various mutants. The results allowed us to construct a proposed pathway for the biosynthesis of daunorubicin glycosides by this streptomycete. KEYWORDS Anthracycline; daunorubicin; biosynthesis; blocked mutants; biotransformation.