• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.1
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• pp.50-53
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• 1999

In this paper, the mechanical movement of lip seal-ring which plays the most important function in stern-tube sealing system and the possibility of leakage caused by pressure fluctuation are studied by theory and experiment. By the finite element method for axial symmetry object which receives the torsional bending load, the displacement and stress analysis of the seal-rings are executed for products of several representative manufacturers of seal-rings, and also the possibility of crack occurance are checked by theoretical analysis. A sample seal-ring id designed and manufactured using the program of displacement and stress analysis developed in this study and made an experimental apparatus to test the sampling seal-ring. The sampling seal-ring functioned excellently, but it had its durability and this problem may be solved by using the Viton instead of NBR.

• Tribology and Lubricants
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• v.10 no.4
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• pp.82-88
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• 1994

This paper deals with a FEM computation as well as measurement of the contact force and distribution of the temperature in rubber lip seals when the sealing interference between the rotating shaft and the lip edge is present. The study of the contact forces and distributions of the temperature and the sealing contact stress has always been one of the basic steps in the process of designing a lip seal. The calculated FEM results indicate that as the sealing interference increases, the contact force moderately increases compared with decreased sealing interference at the seal lip edge and radically increases the contacting width. And the FEM computation of oontact forces including nonlinear problems has been compared with experimental measurements with good agreement. The frictional heat does not dissipate promptly in the rubber seal lip and tends to accumulate at the contacting lip edge especially.

• Korean Journal of Environmental Biology
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• v.24 no.4
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• pp.359-367
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• 2006

The vascular plants of this site were identified as 641 taxa through field investigation; 101 families, 340 genera, 547 species, 80 varieties, 12 forms, 1 subspecies and 1 hybrid. Based on the Rare plants of the Forest Service and Korea Forest Research Institute, 9 taxa were listed except implanted species; Loranthus tanakae, Aristolochia manshuriensis, Aristolochia contorta, Viola albida, Cypripedium macranthum, Schpolia japonioa, Acanthopanax chiisanensis, Rhododendron micranthum. Based on the Korean endemic plants, 18 taxa were listed; Salix purpurea var, japonica, Asarum sieboldii var. mandshuricum for. misnadrum, Persicaria lapathifolia for. alba, Pseudostellaria sylvatica, Aconitum pseudolaeve var. erectum, Corydalis maculata, Corydazis albipetala, Corydalis grandicazyx, Cardamine amaraeiormis, Chrysosplenium barbatum, Filipendula glaberrima, Lespedeza x tomentella, Acanthopanax chiisanensis, Melampyrum setaceum var. nakaianum, Weigela subsessilis, Adenophora triphylla var. hirsute, Cirsium setidens, Saussurea pseudogracilis. Specific plant species by floral region were total 81 taxa (12.6%); Prunus yedoensis in class V, 13 taxa (Thuja orientalis, Cimicifuga heracleiiolia, Sedum middendorffianutn, Rhododendron micranthum, etc.) in class IV, 17 taxa (Equisetum palustre, Aceriphyllum rossii, Angelica gigas, Cirsium setidens, etc.) in class III, 15 taxa (Heloniopsis orientalis, Lychnis cognata, Saxifraga oblongifolia, Viola orientalis, etc.) in class II, 35 taxa (Hosta capitata, Cimicifuga simplex, Chrysosplenium flagelliferum, Campanula punctata, etc.) in class I. So, the naturalized plants were listed 53 taxa and the naturalization index was 8.2%, urbanization index was 20.7%.