| 1. |
- Hahn-Hägerdal, Bärbel, et al.
(författare)
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Production of ethanol from lignocellulosic materials
- 1988
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Ingår i: Animal Feed Science and Technology. - : Elsevier BV. - 0377-8401. ; 21:2-4, s. 175-182
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Tidskriftsartikel (refereegranskat)abstract
- In the bioconversion of lignocellulosic materials to ethanol, the cost of the raw material and the cost of the enzymes have been identified as the major costs for the product. In addition, many lignocellulosic materials contain considerable amounts of five-carbon sugars which are not easily fermented to ethanol. The possibility of improving the cost-intensive steps was investigated. The steam pre-treatment of a fast-growing species of Salix (Q082) was optimized with respect to treatment time and temperature, to give the best glucose yield after enzymatic hydrolysis. It was found that the semi-continuous production of cellulolytic enzymes with Trichoderem reesei Rutgers C30 in an aqueous two-phase system (an extractive fermentation system) increased the amount of recoverable enzyme activity compared with a batch process. It was also found that the enzyme consumption in the hydrolysis of cellulolytic materials, in filter paper units (FPU) g−1 reducing sugars (RS), could be considerably reduced by recirculating the cellulolytic enzymes in an aqueous two-phase system combined with an ultra-filtration unit. For the fermentation of pentoses, it was found that the combination of the commercial enzyme glucose isomerase and regular bakers' yeast, Saccharomyces cerevisiae, was superior to xylose fermenting yeasts. Yields and productivities comparable to those obtained in hexose fermentation could be achieved.
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| 2. |
- Biörnstad, Margareta, 1928-2019
(författare)
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Grundläggningsarbeten i kulturhistorisk miljö
- 1989
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Ingår i: Kulturmiljövård. - Stockholm : Riksantikvarieämbetet. - 1100-4800. ; :3-4, s. 4-7
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Jag välkomnar det här symposiet som jag hoppas skall kunna fungera både som forum för utbyte av erfarenheter och som avstamp för ett fortsatt mer systematiskt arbete, sade riksantikvarie Margareta Biörnstad till symposiedeltagarna. Och det blir en fortsättning. Nyligen togs en första kontakt för bildandet av en referensgrupp som skall initiera en uppföljning av genomförda grundförstärkningar. Diskussioner kommer också att föras för val av framtida forskningsprojekt, eventuellt experimentbyggande.
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| 3. |
- Eriksson, T., et al.
(författare)
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Successive Encoding of Correlated Sources
- 1982
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The encoding of a discrete memoryless multiple source for reconstruction of a sequence with is considered. We require that the encoding should be such that is encoded first without any consideration of , while in a seeond part of the encoding this latter sequence is encoded based on knowledge of the outcome of the first encoding. The resulting scheme is called successive encoding. We find general outer and inner bounds for the corresponding set of achievable rates along with a complete single letter characterization for the special case . Comparisons with the Slepian-Wolf problem [3] and the Ahlswede-Körner-Wyner side information problem [2 ], [9) are carried out.
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| 4. |
- Berbyuk, Viktor, 1953, et al.
(författare)
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Mathematical design of gantry robots for automating assembly processes
- 1989
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Ingår i: Soviet journal of computer and systems sciences. - 0882-4002. ; 27:2, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- A methodology for an automatic selection of the structural schema and the parameters of an assembly robot based on an optimization procedure is described. A finite collection of so-called test positions for the operating element which are determined by the robot purpose and by its characteristic movements is specified. The dynamic, strength, etc. characteristics are computed at these test positions for each structural schema and the constraints for the optimization problem are formulated. The procedure for selecting the structural schema of the robot and its technical parameters consists of minimizing some functional for the indicated constraints. An example of computing the parameters of a gantry robot is given.
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| 5. |
- Berbyuk, Viktor, 1953
(författare)
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On the controlled rotation of a system of two rigid bodies with elastic elements
- 1984
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Ingår i: Journal of Applied Mathematics and Mechanics, Elsevier Science Ltd.. - : Elsevier BV. - 0021-8928. ; 48:2, s. 164-170
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Tidskriftsartikel (refereegranskat)abstract
- The problem of controlling the plane rotational motions of two rigid bodies connected by an elastic rod is studied. One end of the rod is attached to the support by a hinge with a spring, the latter modelling the elastic compliance of the fastening, and the other end is rigidly joined to the load. The Hamilton principle is used to obtain the integrodifferential equations and boundary conditions describing the motion of the system support — spring — rod — load. The following problem is posed: it is required to rotate the system by a given angle by means of the controlling force moment, with quenching of the relative oscillations of the load elements which appear as a result of the deformability of the rod and of the elastic torsion of the spring. Similar problem arise in the study of the dynamics and control of the motion of devices used in transporting loads through space (robots, manipulators, load lifting machines, etc.). In computing their control modes a significant part is played not only by the deformability of the elements, but also by the elastic compliance of the connecting joints. Asymptotic methods are used to botain a solution of the control problem in question for two limiting cases: 1) the mass of the load carried is much greater than the mass of the rod and support, and 2) the rod has high flexural rigidity.
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