• Journal of Species Research
• /
• v.5 no.3
• /
• pp.381-384
• /
• 2016

Two marine amoebae Vannella bursella (Page, 1974) Smirnov et al., 2007 and Pseudoparamoeba sp. were encountered from marine coastal waters of Masan Bay and Garorim Bay (Korea), respectively. These species are described with uninterpreted records based on light-microscopy of living cells and reported taxonomically for the first time from Korea. Diagnostics of these species are as follows. Vannella bursella: size in vivo, $17-29{\mu}m$ long with flattened ovoid, semicircular locomotive forms. Pseudoparamoeba sp.: size in vivo, $10-15{\mu}m$ long with elongated locomotive forms, producing a few short conical pseudopodia from anterior hyaline zone.

• Proceedings of the KWS Conference
• /
• 2002.10a
• /
• pp.499-504
• /
• 2002

The microstructural change associated with the hardness profile in friction stir welded, age-hardenable 6005 Al alloy had been evaluated. Frictional heat and plastic flow during friction stir welding created the fine recrystallized grain (Stir Zone, SZ), the elongated and recovered grain (Thermo-Mechanical Affected Zone, TMAZ) in the weld zone. Heat affected zone (HAZ), which could be only identified by hardness test because there is no difference in the grain structure compared with that of the base metal, was formed beside the weld zone. A softened region had been formed near the weld zone during friction stir welding process. The softened region was characterized by the dissolution and coarsening of the strengthening precipitate during the friction stir welding. The sound joints of 6005 Al alloys were successfully formed under a wide range of the friction stir welding conditions.

• Proceedings of the KWS Conference
• /
• 2006.10a
• /
• pp.109-111
• /
• 2006

In this study, microstructure and mechanical properties for the friction stir welded 2519Al-T87 alloy of the thickness of 38.8mm were studied using DSC, OM, SEM and micro hardness tester. DSC analysis show that GP Zone, ${\theta}'$ and $\theta$ phases in upper part and ${\theta}'$ and $\theta$ phase in lower part of the FSW zone. Recrystallized large grains are observed in HAZ, and elongated small and large grain in the TMAZ. In SZ, very small grains forms by high plastic deformation and heat from friction by tool and specimen.

• Animal Systematics, Evolution and Diversity
• /
• v.30 no.1
• /
• pp.22-25
• /
• 2014

Two species of small gobiid fishes genus Luciogobius, i.e., L. elongatus, L. platycephalus were described as the first records from Korea based on specimens collected from gravel beaches of Gijang-gun, Busan-si, Korea. Luciogobius elongatus is distinguished from congeners by very elongated and naked body, 42-44 vertebrae, 6-7 dorsal soft rays, and no free rays on pectoral fin, and L. platycephalus is characterized by having very depressed head, naked body, 40-41 vertebrae, 10-11 dorsal soft rays, and pectoral fin with only upper 2-4 free rays. We propose the new Korean name "Ga-neun-mi-kkeun-mang-dug", "Nab-jak-mi-kkeun-mang-dug" for L. elongatus and L. platycephalus, respectively.

• Animal Systematics, Evolution and Diversity
• /
• v.33 no.1
• /
• pp.51-55
• /
• 2017

The continuous taxonomic study on decapods from Korean waters revealed that the alpheid shrimps collected from Jejudo Island and Busan were identified as a species belonging to the genus Arete which is an unreported genus from Korean waters. The genus Arete can be distinguished from the most similar genus Athanas by the following. The chelae are broad and oval-shaped in Arete, but in Athanas, the chelae are more or less elongated. The number of carpal segments in the 2nd pereopod is four but five, exceptionally four or six in Athanas. The epipods are present on pereopod 1 and pereopod 2 in Arete, but on pereopod 1-3, exceptionally on pereopod 1 and pereopod 2 or pereopod 1-4 in Athanas. In this paper, Arete dorsalis is reported for the first time from Korean waters. Korean Alpheidae fauna now consists of 27 species of nine genera.

• Journal of Plant Biology
• /
• v.32 no.3
• /
• pp.163-172
• /
• 1989

Nerium indicum has adaxial colleters on each petiole, bract, bracteole, calyx and corolla. The colleters are finger-shaped sometimes lobed structures with tall heads on short stalks. The petiolar colleters are more abundant than those on the bract, bracteole, calyx and corolla but their structure is similar. Meristematic activity in a small group of protodermal and hypodermal cells at the base of the developing leaf gives rise to the colleter that further differentiates by frequent anticlinal and periclinal divisions. Many of the colleters are vascullarized, sometimes a layer of redially elongated cells is present beneath the epithelial cells. Senescence of a colleter begins when the leaves have either completed their growth or are still expanding. In senescent colleters, the central cell cytoplasm and nuclei are considerably reduced. Thin layer chromatography of the freshly harvested exudate of colleter shows the presence of rhamnose, glucose and arabinose sugars.

• Journal of Plant Biology
• /
• v.32 no.4
• /
• pp.255-264
• /
• 1989

Ginseng zygotic embryos, seedlings, and exised cotyledonary nodes were cultured on Murashinge and Skoog's(MS) medium, supplemented with 6-benzyladenine(BA) and gibberellic acid(GA3) to induce flower buds. As the concenteration of nitrogen compounds in MS medium was reduced to half of its strength, the flowering frequency of zygotic embryos increased up to 90%. The optimum concentration of sucrose in the medium for flowering of seedlings was 30-60 g/1. In all cases flower buds were formed on elongated axillary branches from the cotyledonary nodes, while the apices remained vegetative. When zygotic embryos and excised cotyledonary nodes were cultured on the medium, supplemented with all possible combinations of BA, GA3, and abscisic acid(ABA) of 5 $\mu$M indole-3-acetic acid(IAA) in the above combinations did not affect flowering. These results suggest that cytokinins, gibberellins, and inhibitors play primary, permissive, and preventive roles, respectively, in the induction of flowering of ginseng.

• The Korean Journal of Malacology
• /
• v.31 no.3
• /
• pp.253-255
• /
• 2015

The family Olividae includes predatory species with medium-sized, glossy, elongated oval-shaped shell. As sand-dwellers, they are broadly distributed in tropical and subtropical oceans. They feed mostly on other mollusks and carrions including sea snails and bivalves. To date, two species in the genus Amalda (subfamily Ancillinae) have been reported in Korean waters. In this study, Amalda rubiginosa (Swainson, 1823) was collected from Korean waters and morphologically described in details as a first record.

• Journal of The Korean Astronomical Society
• /
• v.42 no.3
• /
• pp.33-37
• /
• 2009

We propose a diagnostic that can resolve the planet/binary degeneracy of central perturbations in caustic-crossing high-magnification microlensing events. The diagnostic is based on the difference in the morphology of perturbation inside the central caustics induced by a planet and a wide-separation binary companion. We find that the contours of excess exhibit a concentric circular pattern around the caustic center for the binary-lensing case, while the contours are elongated or off-centered for the planetary case. This difference results in the distinctive features of the individual lens populations in the residual of the trough region between the two peaks of the caustic crossings, where the shape of the residual is symmetric for binary lensing while it tends to be asymmetric for planetary lensing. We determine the ranges of the planetary parameters for which the proposed diagnostic can be used. The diagnostic is complementary to previously proposed diagnostics in the sense that it is applicable to caustic-crossing events with small finite-source effect.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05a
• /
• pp.346-349
• /
• 2006

Superstructure of reinforced concrete bridges are shortened or elongated due to creep, drying shrinkage, temperature and so on. Most of bridge superstructures are free to shortening and elongation without constraint and stresses will not be induced by creep, drying shrinkage and temperature. But if bridge superstructure are constraint due to wrong setting and functional defects of bridge bearing, very large constraint forces can be induced. In this study, PSCI-Beam by tilt-constructed with constraint and deviation of bearings are presented and the effects of time-dependent constraint stress and temperature loads are investigated.