• Ocean and Polar Research
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• v.32 no.4
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• pp.439-448
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• 2010

General consensus on typical vertical profile of dissolved oxygen in the Ulleung Basin is that dissolved oxygen concentration beyond 300 m decreases with increasing depth. However, the results of our observations in 2005 and 2006 revealed three different dissolved oxygen distribution types in the deep layer of the Ulleung Basin. The first type showed oxygen concentration decreasing with increasing depth (Type-1), the second showed oxygen concentration decreasing very sharply near the bottom boundary layer but constant in the bottom adiabatic layer (Type-2), the final was of the oxygen minimum layer above the bottom boundary layer (Type-3). Type-2 was the most common pattern in the Ulleung Basin. Type-1 was most common close to the Japan Basin, including the Ulleung Interplane Gap, while Type-3 was found around Dok do. Oxygen Consumption Rate (OCR) at surface sediment estimated using the dissolved oxygen distribution at the bottom boundary layer was $0.2{\sim}5.8\;mmol{\cdot}m^{-2}d^{-1}$, which coincided with OCR from direct sediment incubation. This implies that organic matter decomposition at surface sediment may play an important role in dissolved oxygen distribution patterns at the bottom boundary layer of the Ulleung Basin.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.44-48
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• 2017

We explain optical and electrical properties of top and bottom-emission structured alternating-current powder electroluminescent devices (ACPELDs) with Ga-doped ZnO(GZO) transparent electrode. The top-emission ACPELDs were layered as the metal electrode/dielectric layer/emission layer/top transparent electrode and the bottom-emission ACPELDs were structured as the bottom transparent electrode/emission layer/dielectric layer/metal electrode. The yellow-emitting ZnS:Mn, Cu phosphor and the barium titanate dielectric layers were layered through the screen printing method. The GZO transparent electrode was deposited by the sputtering, its sheet resistivity is $275{\Omega}/{\Box}$. The transparency at the yellow EL peak was 98 % for GZO. Regardless of EL structures, EL spectra of ACPELDs were exponentially increased with increasing voltages and they were linearly increased with increasing frequencies. It suggests that the EL mechanism was attributed to the impact ionization by charges injected from the interface between emitting phosphor layer and the transparent electrode. The top-emission structure obtained higher EL intensity than the bottom-structure. In addition, charge densities for sinusoidal applied voltages were measured through Sawyer-Tower method.

• Electrical & Electronic Materials
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• v.9 no.5
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• pp.476-482
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• 1996

The multi-dielectric layer SiO$_{2}$/Si$_{3}$N$_{4}$/SiO$_{2}$(ONO) is used to improve electrical capacitance and to scale down the memory device. In this paper, improvement of the capacitance by reducing the bottom oxide thickness in the nitride deposition with load lock(L/L) vacuum system is studied. Bottom oxide thickness under the nitride layer is measured by ellipsometer both in L/L and non-L/L systems. Both results are in the range of 3-10.angs. and 10-15.angs., respectively, independent of the nitride and top oxide thickness. Effective thickness and cell capacitance for SONOS capacitor are in the range of 50-52.angs. and 35-37fF respectively in the case of nitride 70.angs. in L/L vacuum system. Compared with non-L/L system, the bottom oxide thickness in the case of L/L system decreases while cell capacitance increases about 4 fF. The results obtained in this study are also applicable to ONO scaling in the thin bottom oxide region of memory stacked capacitor.

• 한국해양학회지
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• v.14 no.2
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• pp.54-60
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• 1979

Distribution of drifting larvae of scallop, Patinopecten yessoensis, was studied in the Yeong-il Bay in 1973, 1978, and 1979. The range of the bottom water temperature was 10∼19$^{\circ}C$ and that of salinity was 32.58∼34.55 . The larvae appeared from early March to mid-July with maximum abundance from mid- April to early June. Drifting period of larvae is about a month, and then the larvae begin to settle on the substratum. In the Yeong-il Bay setting period was from early Arpil to late June with maximum abundance from mid-May to eary June. The highest density of drifting larvae was found in the vicinity of Dae-dong-bae(Station H) among the observed stations, and the density was much higher in 1979 than in the other years observed. Vertical distribution of the larvae is closely related to the depth of the water column. High density of the larvae was observed in the bottom layer. The larvae were most abundant in the bottom-most layer, and in the place where the water depth is 24m, 42% appeared in the 4m layer from the bottom, and 80% in the 8m layer from the bottom, and where the water depth is 16m, 50% in the bottom-most 4m, and 90% in the layer up to 8m.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.187-192
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• 2003

To evaluate the oceanographic conditions for the artificial upwelling we measured vertical stratification coefficients, current speed distribution and grain size distribution of bottom sediment in the vicinity of Gukdo and Somaemuldo near Geojedo. There were a strong stratification between surface and bottom layers in summer, the stratification was weak from autumn to winter, and the water was well mixed during winter. In summer nutrient concentration of the bottom layer was 4 times higher than that of the surface layer. Underwater currents were strong in the bottom layer. We conclude that the oceanographic conditions in the area will meet the basic requirement for the construction of artificial upwelling.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.805-808
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• 2002

This study is designed to reduction of hydration heat of 4 layer division-placed mass concrete considering the difference of setting time of super retarding agent. According to the results, peak temperature of plain concrete by hydration heat show $63^{\circ}C$ around the age of 1 days. Hydration heat is lowest in the bottom layer, and highest in the middle of 3rd layer from the bottom. Hydration heat of mock up structure, which is division-placed at the same interval of 1 and 2 days by setting time difference of super retarding agent, is highest in the bottom layer because after peak temperature of 4th layer, hydration reaction progresses in order of 3rd, 2nd and 1st layer. But in mock up structure which is division-placed at the various interval. peak temperature by hydration heat is reduced by about $13^{\circ}C$, compared with plain concrete because after first peak hydration heat of 4th layer (plain concrete), hydration reaction progresses after the drop of hydration heat in order of 3rd, 2nd and 1st layer.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.6
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• pp.120-129
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• 2008

Removal rate of $NO_3-N$ and TN in a free water surface wetland system with litter layer on its bottom was compared with that without one. The system was established on floodplain in the down reach of the Gwangju Stream in 2001. Its dimensions were 31 meters in length and 12 meters in width. Water of the stream was funneled into it and its effluent was discharged back into the channel. Average litter layer of 9.6 cm was formed on its bottom in 2007. The layer and above-ground parts of reeds and cattails on the system were eliminated in Spring 2008. Volumes and water quality of inflow and outflow of the system were analyzed from May to November in 2007 and 2008, respectively. Inflow into the system both in 2007 and 2008 averaged approximately $40m^3/day$ and hydraulic residence time both in 2007 and 2008 was about 1.5 days. Average influent $NO_3-N$ concentration in 2007 and 2008 was 2.16 and 2.05 mg/L, respectively and influent TN concentration in 2007 and 2008 averaged 3.98 and 3.89 mg/L, respectively. With a 0.05 significance level, effluent temperatures, influent concentrations of $NO_3-N$ and TN, and stem numbers per square meter and height of the emergent plants showed no difference between the system with litter layer and without one. $NO_3-N$ removal in the system with litter layer and without it averaged 55.59 and 46.06%, respectively and TN retention averaged 57.24 and 48.97%, respectively. Both $NO_3-N$ and TN abatement rates in the system with litter layer were significantly high (p < 0.001) when compared with those without one. The wetland system having litter layer on its bottom was more efficient for $NO_3-N$ and TN retention than that without one.

• Journal of the Korean Geotechnical Society
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• v.35 no.8
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• pp.5-15
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• 2019

This study was conducted to propose a reasonable requirement regulation of cutoff barriers composed of bottom layer and vertical barrier of offshore landfill for the prevention of contaminant leakage. The bottom layer was composed of impermeable clay layer; vertical walls were composed of double walls; outer wall was composed of steel sheet pile which registed against outer force; cutoff vertical barrier took the role of inner wall. Seepage-advection-dispersion numerical analysis was conducted using SEEP/W and CTRAN/W programs under steady and unsteady flows. The results showed that the values calculated under steady flow showed higher migration of pollutant than those of unsteady flow. The values calculated under steady flow are more valid from a design point of view. Under steady flow and the bottom clay layer and when the vertical barrier are homogeneous and completely well installed, respectively, the minimum required cutoff regulations for hydraulic conductivity, thickness, and embedded depth of the bottom clay layer and vertical barrier were suggested.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.1023-1026
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• 2007

Highly efficient inverted bottom emission organic light emitting device (IBOLED) with a structure of ITO/EIL/Alq3/NPB/WO3/Al was investigated. To enhance electron injection from ITO cathode to Alq3 EML layer, we introduced ultra thin Al layer and Liq layer between ITO and Alq3. The device characteristics showed tune on voltage of 4.5V, the maximum luminance of 21100 Cd/m2 and current efficiencies of 3.56 Cd/A.

• Journal of Magnetics
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• v.10 no.3
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• pp.99-102
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• 2005

Modification in exchange bias of a NiFe/FeMn/NiFe trilayer, on introduction of a nonmagnetic Al layer at the top FeMn/NiFe interface, is investigated in multilayers prepared by rf magnetron sputtering. The introduction of Al layer leads to vanishing of bias of the top NiFe layer. But the bias for the bottom NiFe layer increases steadily with increasing Al layer thickness and attains bias (230 Oe) which is greater than that of the trilayer without the Al layer (150 Oe). When the top NiFe layer thickness is varied, exchange bias has highest value at 12 nm thickness for 1 nm thicknes of Al layer. Ion beam etching of the top NiFe layer also leads to an enhancement in bias for the bottom NiFe layer.