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| 2. |
- Birk, Wolfgang, et al.
(author)
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Model based control for a fine coal injection plant
- 1999
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In: I E E E Control Systems Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0888-0611. ; 19:1, s. 33-43
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Journal article (peer-reviewed)abstract
- Modeling, control, and gas leakage detection in the coal injection process are discussed. It is shown that by use of model-based methods, the flow and pressure of the coal injection vessel are reliably controlled. With the new control law, the coal mass flow can be used as a control parameter for the blast furnace. High injection rates can be used and more coke substituted, This is expected to yield a cost reduction in the iron production. An experimental comparison of the conventional control unit with the one suggested in this article shows that an improvement of the process efficiency can be reached by other means than increasing the capacity of the plant
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| 3. |
- Flachskampf, Frank A, et al.
(author)
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Overestimation of flow velocity through leaks in mechanical valve prostheses and through small orifices by continuous-wave Doppler.
- 1997
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In: Journal of the American Society of Echocardiography. - 0894-7317 .- 1097-6795. ; 10:9, s. 904-914
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Journal article (peer-reviewed)abstract
- The reliability of continuous-wave Doppler flow velocity measurements through small regurgitant lesions, such as in prosthetic leakage, has not been systematically analyzed. To evaluate the accuracy of continuous-wave Doppler in prosthetic valve leakage and small orifices in an in vitro, steady-flow model-flow velocities through the leaks of twelve intact mechanical prostheses and through six circular nozzles (area 0.5 to 20 mm2) were measured at pressure drops between 30 and 105 mm Hg. These results were compared with those predicted by the modified Bernoulli equation. Laser Doppler anemometry of flow velocities through the nozzles was also performed. Despite high correlation, there was substantial overestimation of Bernoulli predicted velocities by echo Doppler in the prosthetic leaks (mean +12.3% +/- 9.4%; range 90.3% to 143.4%). In the nozzles < or = 10 mm2, but not in the largest (20 mm2) nozzle, there was also overestimation of the Bernoulli predicted velocities (mean +6.2% +/- 2%). Laser Doppler anemometry of flow velocities through the nozzles showed slightly lower values than predicted by the Bernoulli equation. Thus, continuous-wave echo Doppler overestimates flow velocities through small orifices. This apparently is, at least in part, due to transit time effects and should be taken into account when using echo Doppler in small (< 10 mm2) orifices, such as in mild to moderate regurgitant lesions and prosthetic valve leakage.
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| 4. |
- Shi, L X, et al.
(author)
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Characterisation of the PsbX protein from Photosystem II and light regulation of its gene expression in higher plants
- 1999
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In: Plant Molecular Biology. - 0167-4412 .- 1573-5028. ; 40:4, s. 737-744
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Journal article (peer-reviewed)abstract
- The location and expression of the previously uncharacterised photosystem II subunit PsbX have been analysed in higher plants. We show that this protein is a component of photosystem II (PSII) core particles but absent from light-harvesting complexes or PSII reaction centres. PsbX is, however, localised to the near vicinity of the reaction centre because it can be cross-linked to cytochrome b559, which is known to be associated with the D1/D2 dimer. We also show that the expression of this protein is tightly regulated by light, since neither protein nor mRNA is found in dark-grown plants.
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