| 1. |
- Adlercreutz, Patrick, et al.
(författare)
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Oxygen supply to immobilized cells : 1. Oxygen production by immobilized Chlorella pyrenoidosa
- 1982
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Ingår i: Enzyme and Microbial Technology. - : Elsevier BV. - 0141-0229. ; 4:5, s. 332-336
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen supply at high cell densities of aerobic organisms is a great problem in immobilized cell preparations. To investigate the possibility of in situ oxygen generation the alga Chlorella pyrenoidosa was immobilized on alginate beads. The conditions for optimal oxygen production were investigated and in long term experiments the preparations were successful for at least 30 days.
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| 2. |
- Adlercreutz, Patrick, et al.
(författare)
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Oxygen supply to immobilized cells : 2. Studies on a coimmobilized algae-bacteria preparation with in situ oxygen generation
- 1982
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Ingår i: Enzyme and Microbial Technology. - : Elsevier BV. - 0141-0229. ; 4:6, s. 395-400
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Tidskriftsartikel (refereegranskat)abstract
- A coimmobilized mixed culture of algae, Chlorella pyrenoidosa, and bacteria, Gluconobacter oxydans, has been studied. The conversion of glycerol to dihydroxyacetone(1,3-dihydroxy-2-propanone), catalysed by the bacteria, was used to indicate the oxygen supply in the immobilized preparation. The oxygen produced by the algae in the coimmobilized preparation was used by the bacteria more effectively than when the cells were immobilized separately and mixed within the reactor. A preparation consisting of only bacteria and no algae was much less effective. The coimmobilized preparation was used in the continuous production of dihydroxyacetone for six days without any significant loss of activity.
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| 3. |
- Adlercreutz, Patrick, et al.
(författare)
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Oxygen supply to immobilized cells - 3. Oxygen supply by hemoglobin or emulsions of perfluorochemicals
- 1982
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Ingår i: European Journal of Applied Microbiology and Biotechnology. - 0171-1741. ; 16:4, s. 165-170
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen supply is a critical point in technical processes when aerobic cells are used in immobilized preparations. This report concerns the use of hemoglobin or emulsions of perfluorochemicals (completely fluorinated organic compounds) to carry oxygen to immobilized cells. Both methods work well and do not seem to harm the cells. The perfluorochemical method of improving oxygen supply showed a higher operational stability than the hemoglobin method.
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| 4. |
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| 5. |
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| 6. |
- Adlercreutz, Patrick, et al.
(författare)
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Oxygen supply to immobilized cells - 4. Use of p-benzoquinone as an oxygen substitute
- 1984
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Ingår i: Applied Microbiology and Biotechnology. - 0175-7598. ; 20:5, s. 296-302
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen supply is a critical point in technical processes when aerobic cells are used in immobilized preparations. In this study p-benzoquinone is used as a substitute for oxygen in the oxidation of glycerol to dihydroxyacetone by immobilized Gluconobacter oxydans cells. The reaction rate was much higher when p-benzoquinone was used compared to when oxygen was used. In an experiment with free cells p-benzoquinone gave a rate more than four times that of oxygen, and with immobilized cells the difference was even greater. p-benzoquinone is more effective than oxygen because it gives a higher maximal reaction rate (the reason for this fact is discussed) and because it is more soluble in water than oxygen. The operational stability of the process is comparatively good. In one experiment the productivity decreased from 60 to 10 mmol/h·g over an 8-day period when p-benzoquinone was used. When oxygen was used in a similar experiment the productivity decreased from 14 to 6 mmol/h·g. The byproduct formed from p-benzoquinone, hydroquinone, can be oxidized to p-benzoquinone which can be re-used. Seven succesive regenerations of p-benzoquinone were performed without any loss of efficiency.
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| 7. |
- Berglund, Kris, et al.
(författare)
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Growth of contact nuclei of citric acid monohydrate
- 1982
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Ingår i: Nucleation, growth, and impurity effects in crystallization process engineering. - : American Institute of Chemical Engineers. - 0816902267 ; , s. 9-13
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Konferensbidrag (refereegranskat)
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| 8. |
- Berglund, Kris, et al.
(författare)
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Modeling of growth rate dispersion of citric acid monohydrate in continuous crystallizers
- 1984
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Ingår i: AIChE Journal. - : Wiley. - 0001-1541 .- 1547-5905. ; 30:2, s. 280-287
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Tidskriftsartikel (refereegranskat)abstract
- A mathematical model for prediction of the crystal size distribution from a continuous crystallizer is presented. The kinetic data used for the model were obtained from batch contact nucleation experiments with citric acid monohydrate. In these experiments, the distribution of growth rates as well as the initial size distribution were estimated. Results from the model indicate that the excess number of crystals usually present at small sizes in continuous crystallizers is due to growth rate dispersion (where crystals of the same size may have different growth rates) and not size dependent growth.
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| 9. |
- Cerreta, M.K., et al.
(författare)
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Raman spectroscopic studies of the structure of supersaturated ammonium dihydrogen phosphate solutions
- 1984
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Ingår i: Industrial crystallization 84. - Amsterdam : Elsevier. - 0444424067 ; , s. 233-236
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Konferensbidrag (refereegranskat)abstract
- Raman spectroscopic studies of quiescent under and supersaturated ammonium dihydrogen phosphate (ADP) aqueous solutions were performed on the nu //1 (totally symmetric or breathing mode) and nu //3 (symmetric twist) H//2PO//4 OVER BAR bands as well as for the nu //1 band of solid ADP and solid diammonium hydrogen phosphate (DHP). The splitting of the non-degenerate ADP nu //1 band in concentrated solution is interpreted in terms of a well-ordered quasi-crystalline solution structure. Increases in nu //1 half-width at half-height support this view.
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| 10. |
- Danielsson, Per-Erik
(författare)
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Implementations of the Convolution Operation
- 1982
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The first part of this article surveys a large number of implementations of the convolution operation (which is also known as the sum-of-products, the inner product) based on a systematic exploration of index permutations. First we assume a limited amount of parallelism in the form of an adder. Next, multipliers and RAM:s are utilized. The so called distributed arithmetic follows naturally from this approach.The second part brings in the concept of pipelining on the bitlevel to obtain high throughput convolvers adapted for VLSI-design (systolic arrays). The serial/parallel multiplier is analyzed in a way that unravels a vast amount new variations. Even more interesting, all these new variations can be carried over to serial/parallel convolvers. These novel devices can be implemented as linear structures of identical cells where the multipliers are embedded at equidistant intervals.
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