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The prey selection of larvae of three common littoral fish species (pike, Esox lucius; roach,Rutilus rutilus; and three-spined stickleback, Gasterosteus aculeatus) was studied experimentally in the laboratory by using natural zooplankton assemblages. Zooplankton prey was offered at four different concentrations to study the functional responses of the planktivores. The diets of pike and sticklebacks were formed mainly of copepod juveniles and adults, which dominated the prey communities, although sticklebacks ate also cladocerans. The diet of roach larvae consisted of rotifers, cladocerans and copepods, without prey selection, in equal proportions indicating a more omnivorous diet. All fish larvae were able to feed selectively although in sticklebacks prey selection was less pronounced. Pike and roach larvae preferred large prey to smaller prey types. Patterns of prey selection are discussed in the context of size-selection theory and apparent vs. true selection.

The research work presents a new design of compression hosiery where compression around a human limb is generated using special air bladders. The pressure inside the air bladders is adjustable. The objective of the research was to study graduated compression and its control on the limb using the prototype with air bladders and two commercial compression products. The compression forces were measured around the limb under a knee in three sectors: a foot, a middle part and an upper part of the leg. Measurements were mainly done in vivo using the limb of a test person – although some pre-trials were done in vitro. During the tests it was concluded that the exact control of the compression was very difficult to achieve due to, for example, the shape and the composition of the limb. Based on the results, the compression values were unstable under the sectors and the graduated compression was nonlinear in the vertical direction for every tested hosiery. There is some analogy concerning the pressure distribution reported about standard mechanical compression hosiery. The results prove that our prototype enables one to achieve very high compression values in seconds, and to manage and to adjust instantly the compression rate in each sector. Efficient controllability and comfort are important matters in the medical treatment, where a patient wears the hosieries for prolonged times.

No abstract

Low voltage direct current (LVDC) distribution is a promising solution, which benefits are large power transfer capacity with low voltage and improvements to reliability and power quality. Tests by the pilot implementation in Elenia Oy have given promising results. The power transfer capacity of the system has been calculated in the paper using voltage drop and maximum load of cable as boundaries. The branches of the MV network, which can be replaced by LVDC distribution, are determined based on the calculations and mass computation of the whole distribution area of Elenia Oy. Based on the done analysis, it can be inferred that LVDC distribution has a good utilization potential.