| 21. |
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| 22. |
- Banda, H., et al.
(författare)
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Der Einfluss von Trübedichte, Körnung und Filtrationsdruck auf den Durchflusswiderstand eines Filterkuchens
- 1987
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Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 28:9, s. 513-520
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Tidskriftsartikel (refereegranskat)abstract
- The effects of slurry concentration, filtration pressure and particle size distribution on the resistance of a filter cake are studied, and an attempt is made to examine the filtration process with reference to the structure of the filter cake. Micrographic analysis clearly demonstrates the effect of particles segregation on filtration rate. The resistance of the cake rises with increasing solids concentration of the slurry, mainly due to a lower degree of particle segregation.
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| 23. |
- Banda, H., et al.
(författare)
-
Strukturanalyse eines Filterkuchens mit dem Bildanalysator
- 1987
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Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 28:4, s. 175-180
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Tidskriftsartikel (refereegranskat)abstract
- Two methods for the consolidation of filter cakes are developed; one of them is based on acrylate plastic as an impregnating medium, and the other uses epoxy resin and is suitable for sulfide-carrying materials, where the first one fails. Even cakes formed from fine particles ( less than 38 mu m) can be consolidated using these methods. Specimens prepared with acrylate offer no difficulties in grinding and polishing; those prepared with epoxy resin, however, call for procedures with bonded grinding media, and the sections are preferably examined under a scanning electron microscope. Direct comparison between the consolidation methods has not been made. Porosity and pore size distribution are measured in filter cakes formed from two different materials using a computerized image analyzer.
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| 24. |
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| 25. |
- Beccu, R., et al.
(författare)
-
Transmission and dissipation of stress wave energy at a percussive drill rod joint
- 1987
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Ingår i: International Journal of Impact Engineering. - 0734-743X .- 1879-3509. ; 6:3, s. 157-173
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Tidskriftsartikel (refereegranskat)abstract
- Transmission and dissipation of stress wave energy at a percussive drill rod joint is determined for three joint types, three joint preload levels, three hammer lengths ( incident wave lengths) and a range of impact velocities ( incident wave amplitudes). The energies of the incident, reflected and transmitted waves are evaluated from measured strains, and then the dissipated energy is determined as the deficit of energy in the two latter waves compared with the first. The accuracy needed is obtained by introducing a compensation factor and determining its value from the requirement of momentum conservation. The experimental results for threaded standard joints are compared with experimental results for threadless dummy joints, made in one piece, and also with theoretical results. The latter are based on one model which represents the joint as a well on a one- dimensional elastic rod (characteristics impedance or CI model) and on another model which represents the joint as a rigid mass between one-dimensional elastic rods (rigid mass or RM model). For the joints 70-100% of the incident wave energy is transmitted and 0-20% is dissipated. The corresponding figures for the dummies are 90-100% and (±)1%, repectively. The latter figure indicates the inaccuracy in the measurement and evaluation procedures. The two models agree fairly well with the dummies. Under certain conditions they also give reasonably accurate predictions for the energy transmitted through a joint. As they sometimes give quite inaccurate results for energy transmission and furthermore fail to predict energy dissipation they need be refined.
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| 26. |
- Benckert, Lars, et al.
(författare)
-
Measuring true in-plane displacements of a surface by stereoscopic white-light speckle photography
- 1987
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Ingår i: Optical Engineering. - : SPIE-Intl Soc Optical Eng. - 0091-3286 .- 1560-2303. ; 26:2, s. 167-169
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Tidskriftsartikel (refereegranskat)abstract
- When in-plane surface deformations are measured using white-light speckle photography, errors arise if an out-of-plane displacement is present. Stereoscopic photography resolves this problem and makes possible the measurement of true in-plane displacements. A rigid-body translation is introduced to determine unambiguously the direction of the displacement
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| 27. |
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| 28. |
- Bergman, Bo, et al.
(författare)
-
A note on some test statistics against HNBUE
- 1987
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Ingår i: Annals of the Institute of Statistical Mathematics. - 0020-3157 .- 1572-9052. ; 39:3, s. 483-488
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Tidskriftsartikel (refereegranskat)abstract
- Some comments and extensions are given to the paper on statistics for testing exponentiality against the HNBUEE property (i.e. {Mathematical expression} ≦μ exp(-t/μ), t≧0) by Basu and Ebrahimi
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| 29. |
- Bergman, Bo, et al.
(författare)
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TTT-concept and replacements to extend system life
- 1987
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Ingår i: European Journal of Operational Research. - 0377-2217 .- 1872-6860. ; 28:3, s. 302-307
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Tidskriftsartikel (refereegranskat)abstract
- In a number of papers the current authors have illustrated how the Total Time on Test (TTT) concept can be used when analysing the ordinary age replacement problem and different generalization thereof. In this paper we show that the TTT-concept is very useful also when analysing another replacement problem discussed by C. Derman et al. in which the replacements of a vital component, for which there are n space units, are made with the goal of maximizing the expected system life. (12 refs.)
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| 30. |
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