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- Ahlstrom, R., et al.
(författare)
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School children's preferences for food combinations
- 1990
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Ingår i: Food Quality and Preference. - 0950-3293 .- 1873-6343. ; 2:3, s. 155-165
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Tidskriftsartikel (refereegranskat)abstract
- Students from the 4th, 8th and 11th grades (N = 177) expressed their opinions as to which foodstuffs belong together in a meal. They did this by selecting and grouping cards that depicted the names and pictures of 25 foodstuffs typically offered in their school lunches. Subjects were allowed to create up to 10 different meals under one of four instructions. The cards were dispensed from a specially designed box that could hold single or multiple copies of each food item. Younger students created significantly more meals with few components than did the older students. The types of foodstuffs selected and their groupings were highly similar across grades and for both boys and girls. The meals tended to correspond to those actually available in the school lunch program, but more than 50% of the creations were unique in that each of them was produced by one or two students. These findings suggest that school nutritionists and administrators should strive for maximum variety in their lunch menus. © 1991.
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| 2. |
- Andre, C., et al.
(författare)
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Predation on Settling Bivalve Larvae by Benthic Suspension Feeders - the Role of Hydrodynamics and Larval Behavior
- 1993
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Ingår i: Marine Ecology-Progress Series. - 0171-8630. ; 97:2, s. 183-192
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Tidskriftsartikel (refereegranskat)abstract
- Predation by the suspension-feeding infaunal bivalve Cerastoderma edule on settling C. edule larvae was studied in a flume boundary-layer flow. The density of settled larvae was reduced by 33% in an area of 5 cm2 enclosing individual adults. Mean survival time for competent C. edule larvae drifting over sediment populated with feeding adults (380 ind. m-2) was 64 s, and 75% of the observed larvae were inhaled by adults. Observations of the siphonal currents produced by C. edule and the swimming behaviour of larvae were combined in a computer model to assess the importance of adult density and boundary-layer flow on the predation risk experienced by settling larvae. Survival of settling larvae decreased drastically with increasing adult density, whereas increased flow velocity caused only a slightly higher predation risk. Although reduction in larval settlement on the scale of individual adults may be small or moderate, inhalation of settling larvae by populations of resident suspension feeders may cause a significant decrease in settlement on a larger scale (10(1) to 10(3) m).
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| 6. |
- Jonsson, Per R., 1957, et al.
(författare)
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Swimming Behavior of Marine Bivalve Larvae in a Flume Boundary-Layer Flow - Evidence for near-Bottom Confinement
- 1991
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Ingår i: Marine Ecology-Progress Series. - 0171-8630. ; 79:1-2, s. 67-76
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Tidskriftsartikel (refereegranskat)abstract
- The swimming behaviour of settling larvae of the bivalve Cerastoderma edule (L.) was studied in still water and in a flume boundary-layer flow. In still water and slow flow the larvae swam upward in helices with high directionality, which is interpreted as morphological geotaxis. By reducing velar propulsion larvae regularly descended towards the bottom due to gravity. In moderate and fast flow (5 to 10 cm s-1) the larvae became confined to the viscous sublayer, where they slowly drifted in the streamwise direction at 0.45 to 1.6 mm s-1, less than 1 mm above the sediment surface, periodically making contact with the bottom. At flow velocities exceeding 15 cm s-1 the steady near-bottom drift changed to bed-load transport of tumbling larvae with high probability of resuspension. Based on kinematic and force analysis of swimming behaviour we suggest that boundary-shear induced torque restricts the settling larvae to the viscous sublayer. This near-bottom confinment may explain how habitat selection in benthic bivalves is realized under natural flow regimes.
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| 7. |
- Lindegarth, Mats, 1965, et al.
(författare)
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Fluorescent Microparticles - a New Way of Visualizing Sedimentation and Larval Settlement
- 1991
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Ingår i: Limnology and Oceanography. - 0024-3590. ; 36:7, s. 1471-1476
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Tidskriftsartikel (refereegranskat)abstract
- Methods for preparing fluorescently labeled microparticles and bivalve larvae (Cerastoderma edule) are presented. The labeling is cheap, easy, and allows production of great quantities of fluorescent microparticles and larvae. Fluorescent visualization can be used as a tool to analyze hydrodynamical processes in the benthic boundary layer and to directly observe behavioral patterns in settling larvae.
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| 8. |
- Mäntylä, P., et al.
(författare)
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Improved thickness and shape accuracy with advanced pass scheduling in plate rolling
- 1992
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Ingår i: Journal of Materials Processing Technology. - : Elsevier BV. - 0924-0136 .- 1873-4774. ; 34, s. 255-263
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Tidskriftsartikel (refereegranskat)abstract
- The so-called CROWN programs have been developed as a result of the co-operation in the Scandinavian Steel Industry. They consist of separate physical models for calculation of plate or strip temperature and roll thermal expansion, wear and elastic deformation. Flatness and residual stresses in the material are deduced from the relative change in profile during rolling with the aid of a shape vector method which considers the transverse metal flow in the roll gap. The CROWNON model is an on-line model which can be used for process control in rolling mills. A new optimized pass schedule generation system has been developed for the plate mill in Rautaruukki. The pass schedule is calculated in the forward direction for the sizing pass, broadside passes and the longitudinal passes. The drafts for the broadside and the first longitudinal passes are limited by maximum force, torque and strain. For the last longitudinal passes, the shape vector method is applied and the draft is restricted by the maximum steepness and flatness criteria. The change in the relative elongation differences between the centre and the edge of the plate together with experimentally determined values for the transverse metal flow (e.g. ξ-values) are used in the schedule calculation. To predict correct rolling loads during the scheduling, an adaptive temperature-dependant force-draft model is used based on statistical analysis of the rolling process. The system has decreased the number of passes, improved the yield and has provided the possibility of rolling thin, wide plates, e.g. 4.7 × 3250 mm with good flatness and minimum crown. The barrel length of Rautaruukki's plate mill is 3,6 m and the maximum rolling speed is 5 m/s. During the last years two dimensional and three dimensional Finite Element simulations of hot rolling of flat products have been made. The calculated rolling forces show very good agreement with experiments made in Rautaruukki's plate mill. © 1992.
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