• Proceedings of the Korean Geotechical Society Conference
• /
• 2000.11a
• /
• pp.419-426
• /
• 2000

Waste landfill consists of cover layer, glass, robber, sheet, food waste, etc and is in very loose state. So, the proper method must be applied to ground improvement of waste landfill according to its characteristics and conditions. In this paper, analysis for field tests as static loading test, bearing capacity test were peformed. In result, PG pile method proved to be effective and economic, because it affected increase of end bearing capacity, the prevention of differential settlement and over 20% increase of density by expansion of pile.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2000.10a
• /
• pp.135-139
• /
• 2000

Waste landfill consists of cover layer, glass, robber, sheet, food waste, etc and is in very loose state. So, the proper method must be applied to ground improvement of waste landfill according to its characteristics and conditions. In this paper, analysis for field tests as static loading test, bearing capacity test were performed. In result, PG pile method proved to be effective and economic, because it affected increase of end bearing capacity, the prevention of differential settlement and over 20% increase of density by expansion of pile.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.22 no.4
• /
• pp.32-40
• /
• 1986

A model experiment of purse seine by the circulating water tank was carried out on the changes of net shape and the tension of purseline under operation in two layer current. In the circular tank, the two layer current was made by cutting off the current of upper layer and producing the bottom current by the equipment shown in Fig. 1. The model experiment of purse sein was made on a reduced scale 1 :400, and the experiment was carried out according to the Tauti's model law. When the bottom current of O. 5 knot flows to lower part of three-eighths of net, following results are derived. The depth of sinkerline reached only about 80% of that of no current set. The horizontal shift of sinker line caused by the bottom current is maximized in tight set. The enclosed area by the floatIine immediately after the completion of set net is 61. 5% in tight set, 50. 0 % in loose set and 54. 1 % in lateral set of those in the case of no current. In the first half period of pursing, the tension of the purseline is enhenced by the bottom current and the pattern of increasing is irregular in the tension curves.

• Geomechanics and Engineering
• /
• v.32 no.6
• /
• pp.567-581
• /
• 2023

Enhanced vertical load capacity of the ground reinforced with the stone columns drew great attention by the researchers as it deals with many of the geotechnical difficulties associated with the weak ground. Recently, it has been found that the stone columns are also prone to fail under the shear load when employed beneath the embankments or the foundations susceptible to lateral loads. In this study, the effect of various encasement conditions on the lateral deflection of stone columns is investigated. A method of dual layers of encasement has been introduced and its the effect on lateral load capacity of the stone columns has been compared with those of the single encased stone column and the un-encased stone columns. Large shear box tests were utilised to generate the shear deformation on the soil system under various normal pressure conditions. The stiffness of the soil-stone column combined system has been compared for various cases of encasement conditions with different diameters. When subjected to lateral deformation, the encased columns outperformed the un-encased stone columns installed in loose sand. Shear stress resistance is up to 1.7 times greater in dual-layered, encased columns than in unencased columns. Similarly, the secant modulus increases as the condition changes from an unencased stone column to single-layer encasement and then to dual-layer encasement, indicating an improvement in the overall soil-stone column system.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.4
• /
• pp.51-59
• /
• 2010

This article is a case study for the example of the foundation design, in the project area of the silty sand layer that is spread shallowly with loose status, to make the site for a structure and build it up. The site is located on the dredged and reclaimed land in Gun-San and In-Cheon that is formed the silty sand layer with loose status range around 10 meters underground level, the solid ground for the lower pile is shown around 20 meters underground level. Therefore, this area has to be done by ground improvement when applying for the shallow method of foundation. Dynamic compaction method considering the conditions of the design loads in each zone has to be decided through comparative review on the method of foundations and pilot field test was conducted, and drilling investigation and plate bearing test were achieved as well. The analysis results of the tests prove that stability against bearing capacity was acquired by ground improvement effect.

• Mycobiology
• /
• v.30 no.3
• /
• pp.117-127
• /
• 2002

Cleistothecial development in Aspergillus nidulans(teleomorph, Emericella nidulans) was examined with the transmission electron microscopy. Cleistothecial initial was a small coiled lump of cells, ca. 6 ${\mu}m$ in diameter, which was consisted of a slightly swollen core with a short "tail" hypha. Initials were wrapped with a loose layer of hyphae. Core cells of cleistothecial initials were broad and multinucleated at first, then formed dikaryotic ascogenous cells, followed by post-meiotic tetra-nucleate or octa-nucleate protoasci and finally mature ascospores. Croziers were formed early during cleistothecium development. The peridial layer of mature cleistothecia was derived from the wrapping hyphae which originally invested the young cleistothecium. Completion of peridial layers development was associated with the depositing of a non-enzyme reactive material around peridial cells. $H\ddot{u}lle$ cell formation during the cleistothecial development appeared to be somewhat coordinated with the developmental stages of cleistothecium.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.299-306
• /
• 2001

Crushed Stone Pile(CSP) is one of the ground improvement methods available to loose sand and clayey ground by forming compacted CSP in the weak soil layer. The effects of this method are enhancement of ground bearing capacity, reduction of settlement and prevention of lateral ground movement in cohesive layer, reduction of liquefaction potential in sandy ground. This study performs model tests in 1.0m${\times}$1.0m${\times}$1.0m and 1.5m${\times}$1.5m${\times}$l.2m model tank to observe bearing capacity of CSP treated ground. The area replacement ratio of CSP composite ground varies 20%, 30% and 40% with square grid pattern. After the composite ground was consolidated under pressure of 0.5kg/$\textrm{cm}^2$ and 1.0kg/$\textrm{cm}^2$, load tests were carried out. The results show that ultimate bearing capacity increases with area replacement ratio and the preconsolidation pressure of ground.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1992.10a
• /
• pp.137-144
• /
• 1992

This paper reports a case study of dynamic consolidation. The objective of the study is to evaluate the effectiveness of ground improvement at the site for Hyundai Petrochemical Compound constructed at Daesan-Myeon, Seosan-Gun in the western shores of Korea. The site ground was prepared by filling on the existing soft marine deposit which consists of a loose granular soil layer and a medium stiff clay layer. For the stabilization of site ground, the compaction was executed in three different procedures with same pounder weigh, drop height and imprint spacing. The post investigation showed that the object was successfully achieved indicating a significant increase of bearing capacity of the treated ground. In this study the effectiveness of dynamic consolidation is evluated for various factors the applied energy, temping sequences, the radial distance from the imprint location and the depth of bed rock.

• Korean Journal of Ichthyology
• /
• v.28 no.3
• /
• pp.147-155
• /
• 2016

This study describes the cell type, ultrastructure and histochemical characteristics as a preliminary study for the research on integument of the smooth lumpsucker, Aptocyclus ventricosus in accordance with the physiological and environmental changes using light and electron microscopes. The SEM revealed the presence of well-developed finger printing structure in the skin surface. The skin surface of the smooth lumpsucker showed an irregular folds in cross section of light microscope. Integument is composed of outer epidermal and inner dermal layer. The epidermal layer is a stratified layer composed of epithelial cells, mucous cells, vacuolar cells, and granular cells. Epithelial cells are classified into superficial, intermediated, and basal cell. The superficial cells were the squamous with well-developed microridges on the free surface, and the microridges were covered with glycocalyx. The mucous cells of unicellular gland were mainly distributed in the apical layer of epidermis and contained mucosal materials of neutral glycoprotein. The vacuolar cells of unicellular gland were mainly distributed in the mid and basal layer of epidermis. The proportion of mucous cells and vacuolar cells were $7.0({\pm}1.07)%$ and $40.6({\pm}3.31)%$ of epidermal area, respectively. The granular cells contained membrane bounded secretory granules with high electron density and developed cell organelles in the cytoplasm. The dermal layer was loose connective tissue layer and composed of mainly collagen fibers. It also contained blood vessels and chromatophores of melanophores and reflecting platelets.

• Nuclear Engineering and Technology
• /
• v.40 no.2
• /
• pp.147-154
• /
• 2008

The general corrosion behavior of austenitic and ferritic steels(316L, 304, N controlled 304L, and 410) in supercritical water is investigated in this paper. After exposure to deaerated supercritical water at $480^{\circ}C$/25 MPa for up to 500 h, the four steels studied were characterized using gravimetry, scanning electron microscopy/energy dispersive X-ray spectroscopy(SEM/EDS), X-ray photoelectron spectroscopy(XPS), and X-ray diffraction(XRD). The results show that the 316L steel with a higher Cr and Ni content has the best corrosion-resistance performance among the steels tested. In addition to the oxide layer mixed with $Fe_{3}O_{4}$ and $(Fe,Cr)_{3}O_{4}$ that formed on all the samples, a $Fe_{3}O_{4}$ loose outer layer was observed on the 410 steel. The corrosion mechanism of stainless steels in supercritical water is discussed based on the above results.