Efficient Part Load Combined Cycle Operation.

LecturePg. 31-36During the oil crisis in the 1970s, many electric utilities assigned their base load portion of electric generation requirements to nuclear and coal fired steam plants. The intermediate duty in some cases was assigned to combined cycles or to oil fired steam plants. The peak duty under 1000 hr was assigned in many cases to combustion turbines. By innovative boiler modification, the peaking combustion turbine can be combined with a steam plant to provide the combustion air for the steam plant boiler with a wide load variation at good efficiency. In addition to maintaining high efficiency at part load, it increases the plant capacity 6 to 7 percent at full load, decreases NO(subscript x) generation, varies the air flow to an existing boiler 10 percent and up to 20 percent using a new combustion turbine and provides a system such that the gas turbine can automatically be removed from the cycle without tripping the steam cycle

Analysis of Processes of Junior High School Students' Group Discussion

This paper describes research based on observational data of junior high school students' discussion processes in small group contexts solving problem. Using Mercer's models of three distinctive social modes of thinking, or disputational talk, cumulative talk and exploratory talk, we analyzed and interpreted discourse data of students from 7th grade to 9th. As the results, we see most students in all grades often discussing in the way of cumulative talk. We also see the exploratory talk, which helps group to solve problem, in 7th and 8th grade students' discussion