Optimal Power Flow of Multiple Energy Carriers

This paper presents an approach for combined optimization of coupled power flows of different energy infrastructures such as electricity, gas, and district heating systems. A steady state power flow model is presented that includes conversion and transmission of an arbitrary number of energy carriers. The couplings between the different infrastructures are explicitly taken into account based on the new concept of energy hubs. With this model, combined economic dispatch and optimal power flow problems are stated covering transmission and conversion of energy. A general optimality condition for optimal dispatch of multiple energy carriers is derived, and the approach is compared with the standard method used for electrical power systems. Finally, the developed tools are demonstrated in examples     

The beta-gal interferon assay: a new, precise and sensitive method

Cells of a human glioblastoma line were stably transfected with a glial fibrillary acidic protein (GFAP) promoter sequence/lacZ reporter gene. Following this modification, they produced Escherichia coli beta-galactosidase constitutively in amounts that could be measured through their conversion of an added fluorophore into a product readily estimated by fluorimetry. Human interferons (IFN) selectively and in a dose-dependent manner reduce the formation of beta-galactosidase in this system. We have used it as the basis for a novel assay that is sensitive (4-40 pg/ml), precise, completed in 30 h, and applicable to both type I and type II human IFNs. Statistical analysis showed interassay relative standard deviations ranging from 5% to 11%, and most individual assays revealed potencies with limits of error within 85%-115%. Neither partially trypsin-digested IFN nor the other cytokines and mitogens we tested reacted in this system, except for tumor necrosis factor-alpha (TNF-alpha). The high selectivity was further shown by the loss of response to IFN in the presence of the appropriate specific anti-IFN or anti-IFN-gamma receptor antibodies.     

Reducing the total discharge from a large WWTP by separate treatment of primary effluent overflow.

At many large wastewater treatment plants (WWTPs) the increased hydraulic load, caused by combined sewer systems during storm events, results in primary effluent overflow when the capacity of further treatment is exceeded. Due to stringent effluent standards, regulating the total discharge from the WWTPs, the Rya WWTP in G?teborg and the Sj?lunda WWTP in Malm? will have to reduce the impact of primary effluent overflow. Separate, high rate, precipitation processes operated only during high flow conditions have been investigated in pilot units at the two WWTPs. Precipitation in existing primary settlers operated at a surface loading of 3.75 m/h removed phosphorus to 0.35 mg/l. The Actiflo process was also shown to remove suspended solids and phosphorus well. BOD was reduced by 50-60%. With such processes the overall effluent concentrations from the plants can be reduced significantly. Key upgrading features are small footprints, short start up time and high efficiency.     

Psychological reactions during in-vitro fertilization: similar response pattern in husbands and wives

The purpose of this study was to examine differences in daily emotional, physical and social reactions among husbands and wives during in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Forty couples about to undergo ICSI or IVF at a private infertility clinic monitored their emotional, physical and social reactions daily for one complete treatment cycle from the first day of stimulation until the outcome of treatment was known (approximately 35 days). The results showed that men and women had a similar response pattern to oocyte retrieval, fertilization, embryo transfer and the pregnancy test. These stages were associated with the most significant changes in reactions for both spouses. The pattern of results suggested that the most important psychological determinant of reactions during IVF was the uncertainty of treatment procedures. Spouses appeared to be equally sensitive to this uncertainty and both appeared to respond to it with ambivalent feelings involving emotional distress and positive feelings of hope and intimacy.