• Title/Summary/Keyword: vertical raking

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Condition assessment of raking damaged bulk carriers under vertical bending moments

  • Kim, Do Kyun;Yub, Su Young;Choi, Han Suk
    • Structural Engineering and Mechanics
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    • v.46 no.5
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    • pp.629-644
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    • 2013
  • This paper concerns about the raking damages on the ultimate residual hull girder strength of bulk carriers by applying the modified R-D diagram (advanced method). The limited raking damage scenarios, based on the IMO's probability density function of grounding accidents, were carried out by using sampling technique. Recently, innovative method for the evaluation of the structural condition assessment, which covers the residual strength and damage index diagram (R-D diagram), was proposed by Paik et al. (2012). This concept is applied in the present study and modified R-D diagram, which can be considered vessel size effect, is then proposed. Four different types of bulk carrier structures, i.e., Handysize (37K), Supramax (57K), Kamsarmax (82K) and Capesize (181K) by Common Structural Rule (CSR), were applied to draw the general tendency. The ALPS/HULL, intelligent supersize finite element method, was employed for the ultimate longitudinal strength analysis. The obtained empirical formulas will be useful for the condition assessment of bulk carrier structures. It can also cover different sizes of the bulk carriers in terms of ultimate longitudinal strength. Important insights and findings with useful guidelines developed in this study are summarized.

Structural Damage and Residual Strength of Ships in Grounding with a Forward Speed (전진형 좌초시 선박의 구조손상 및 잔류강도)

  • J.K. Paik;T.K. Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.32 no.4
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    • pp.73-86
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    • 1995
  • In this paper, the mechanics of ships in grounding with a forward speed is analyzed. A raking damage estimate model in grounding of ships is proposed. The accuracy and applicability of the model are verified by a comparison of experimental results. The progressive collapse analysis of damaged gull sections under vertical bending moments is described by using the ALPS/ISUM computer code. The procedure is applied to grounding simulation of a double hull tanker with a transverseless system.

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Characterization and Control of Vascellum curtisii (Berkeley)Kreisel Causing the Fairy Ring Arcs in the Golf Course in Korea (골프코스에서 페어리링의 원인이되는 Vascellum curtisii의 특징과 방계)

  • Choi, Dae-Hong;Lee, Jung-Han;Kim, Hee-Kyu
    • Asian Journal of Turfgrass Science
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    • v.22 no.2
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    • pp.171-178
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    • 2008
  • We have found the clusters of tiny spiny puffball-like mushrooms growing gregariously in fairy ring (arcs) rimmed by a zone of darker green grass in the golf courses. Macroscopic as well as microscopic characters were examined for the morphology of fruiting body. Exoperidium is thin and densely spiny with minute fibrillae at early stage. The connivent spines were soft and quite persistent. In age, the fibrillae scrumble away with a powdery coating, which leaves white endoperidium becoming pale brown. It's interior was white and fleshy at first, but turns into an olive-colored dust as the gleba, the spore-producing tissue, develops to maturity and loaded with olive-brown spore mass. Then, distinct apical pore developed on the endoperidium. Rudimentary subgleba(sterile base) was narrow, chambered, delineated from the gleba by a membrane in young material. These characters suggested this fungus is a Vascellum, a member of the family Lycoperdaceae. The shapes of the spores were globose, echinulate, $3{\sim}3.5{\mu}m$ in diameter, thick-walled, and olive brown. Capillitial threads were $8-9{\mu}m$ wide, mostly colorless in KOH solution and thin-walled, which designated as "paracapillitium". This is an another character that distinguishes this mushroom from Lycoperdon spp. The spines developed on exoperidium were characteristically connivent; their apices joined together in a point, leaving a space below, which gives the appearance of vault to each group of usually 5 to 6 fibrillae. Based on the above characters, this fungus is identified as Vascellum curtisii (Berkeley). The characters distinguishable this from Lycoperdon pulcherrimum, and Vascellum pretense are discussed in detail. Control trial was also attempted. Strong vertical raking(SVR) followed by applying 500x detergent solution (Spark, Aekyung Co. Seoul) resulted in excellent control over any other treatments. In this plot, fruiting body was not developed throughout the end of mushroom growing season.