• Journal of Korean Society of Rural Planning
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• v.30 no.2
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• pp.69-77
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• 2024

As impervious area increases due to urbanization, rainfall on the impervious area does not infiltrate into the ground, and stormwater drains quickly. Low impact development (LID) practices have been suggested as alternatives to infiltrate and store water in soil layers. The practices in South Korea is applied to urban development projects, urban renewal projects, urban regeneration projects, etc., it is required to perform literature research, watershed survey, soil quality, etc. for the LID practices implementation. Prior to the LID implementation at fields, there is a need to simulate its' effect on watershed hydrology, and Storm Water Management Model (SWMM) provides an opportunity to simulate LID practices. The LIDs applied in South Korea are infiltration-based practices, vegetation-based practices, rainwater-harvesting practices, etc. Vegetation-based practices includes bio-retention cell and rain garden, bio-retention cells are mostly employed in the model, adjusting the model parameters to simulate various practices. The bio-retention cell requires inputs regarding surface layer, soil layer, and drain layer, but the inputs for the drain layer are applied without sufficient examination, while the model parameters or inputs are somewhat influential to the practice effects. Thus, the approach to simulate vegetation-based LID practices in SWMM uses was explored and suggested for better LID simulation in South Korea.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.781-792
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• 2016

This paper presents a new approach to enhance the data retention of logic-compatible embedded DRAMs. The memory bit-cell in this work consists of two logic transistors implemented in generic triple-well CMOS process. The key idea is to use the parasitic junction capacitance built between the common cell-body and the data storage node. For each write access, a voltage transition on the cell-body couples up the data storage levels. This technique enhances the data retention and the read performance without using additional cell devices. The technique also provides much strong immunity from the write disturbance in the nature. Measurement results from a 64-kbit eDRAM test chip implemented in a 130 nm logic CMOS technology demonstrate the effectiveness of the proposed circuit technique. The refresh period for 99.9% bit yield measures $600{\mu}s$ at 1.1 V and $85^{\circ}C$, enhancing by % over the conventional design approach.

• KSBB Journal
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• v.6 no.4
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• pp.395-402
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• 1991

A new process was developed to degrade PVA(polyvinyl alcohol) in desize wastewater. Two symbiotic bacteria of Pseudomonas strain G5Y and PW were immobilized on the media by adsorption. A natural zeolite was chosen as the best media considering cell adhesion capacity, sedimentation rate, and material cost. PVA and COD removal efficiencies of this system for synthetic wastewater were 84% and 85% at the retention time of 6 hr, when the volumetric loading rate was PVA 8g/L·day and COD 8g/L·day, and cell density was 19,775 mg/L. In case of desire wastewater, they were 78% and 72% at the retention time of 6 hr, respectively, when the volumetric loading rate was PVA 8g/L·day and COD 13.2g/L·day, and cell density was 32,899mg/L. In case of desize wastewater, PVA and COD removal efficiencies were lower than synthetic wastewater, but cell density of the desize wastewater was lower than that of the synthetic wastewater, because there were insufficiency of necessary nutrition and variety of desize materials in the desize wastewater. A pilot test was successfully performed showing 88% and 82%, PVA and COD removal efficiencies at the retention time of 24 hr, when volumetric loading rate were 4.7 PVA g/L·day and COD 6.9g/L·day, and cell density was 12,,324 mg/L.

• Journal of the Korean Wood Science and Technology
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• v.20 no.4
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• pp.57-64
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• 1992

The unique cell wall micropores of pulp fiber can be utilized as loading site in variety of important practical application which could be the basis of new papermaking technologies. One of these includes the manufature of paper containing higher levels of in situ filler precipitated. Hardwood pulp fiber were first impregnated with the solution of sodium carbonate($Na_2CO_3$). The micropores in cell wall of pulp fibers were filled with the liquid salt solution. The second calcium nitrate($Ca(NO_3)_2$) solution formed an insoluble calcium carbonate($CaCO_3$) precipitate within the cell wall micropores by interacting with the first sodium carbonate solution. The effects of chemical concentration and dryness of pulp fibers on the retention of cell wall micropore loaded filler were investigated. The paper properties of cell wall micropore loaded pulp fibers were compared with those of conventionally loaded and lumen loaded pulp fibers. Also the presense of the fillers within the cell wall micropore was observed by SEM. Increasing the chemical concentration to generate the calcium carbonate increased the retention of filler in cell wall micropore loaded pulp fibers. The particle size distribution of precipitated calcium carbonate ranged from $0.1{\mu}m$ to $80{\mu}m$. But, the average particle size of cell wall micropore loaded calcium carbonate was $4{\mu}m$. The paper made from never dried pulp fibers, the cell wall micropores which were filled with calcium carbonate, had better mechanical and optical properties than those of conventionally loaded or lumen loaded pulp fibers.

• The Korean Journal of Nuclear Medicine
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• v.23 no.1
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• pp.41-48
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• 1989

$^{99m}Tc-Pertechnetate\;(TcO_4^-)$ is concentrated by the stomach after intravenous injection, allowing the detection of ectopic gastric mucosa. It has been used to develop a noninvasive test of gastric secretion. However the cellular site of concentration is still controversial, that is whether mucin-secreting epithelial cell or acid-secreting parietal cell. This study is planned to investigate the effects of cimetidine and gastric acidity on the retention of $TcO_4^-$ in the gastric wall of the rat. Also we further attempted to clarify the uptake and secreting cell of $TcO_4^-$ in the gastric mucosa. One hundred rats were divided into two groups, preliminary (40 rats) and main examination group (60 rats). Preliminary examination group was composed of fasting group (20 rats) for the detection of the time for reaching stable $TcO_4^-$ retention ratio in gastric wall and post-prandial group (20 rats) for the detection of the time for reaching the maximal gastric acidity. Main examination group was composed of fasting group (30 rats), which was subdivided into control group (10 rats), cimetidine group (10rats), $Mylanta^{(R)}$ group (10 rats) and post?prandial group (30 rats), which was subaivided into 90 min group (10 rats), 90 min cimetidine group (10 rats), and 120 min group (10 rats). Retention ratio (%) of $TcO_4$ in the gastric wall and the pH of the gastric contents were measured in the extracted stomach of the six groups. Gastric wall retention ratio of $TcO_4^-$ was calculated by the gastric wall radioactivity (cpm) divided by total gastric radioactivity (cpm) at 30 mins after intravenous injection of 0.4 mCi of $TcO_4^-$. The results were as follows: 1) The time required for reaching stable $TcO_4$ retention ratio and the lowest gastric PH were 30 min and 90 min, respectively. 2) In the fasting group, the gastric wall retention ratio of $TcO_4^-$ was significantly increased in the cimetidine group, compared with the control group (P < 0.01). However there was no significant difference between the control and $Mylanta^{(R)}$ group 3) The $TcO_4^-$ retention ratios of 90 min and 120 min groups were lower than that of the fasting control group (p < 0.05), either. After administration of cimetidine, the retention ratio was significantly increased in 90 min group (p < 0.01). 4) While $TcO_4^-$ retention ratio and gastric pH were well correlated in the post-prandial 120 min group (r=0.7112, p<0.05), in the post-prandial 90 min and 90 min cimetidine groups correlated poorly. However, there was no correlation in the three fasting groups at all. Referring the above results, we infer that $TcO_4^-$ is secreted into the gastric lumen by both parietal and non-parietal cells, with dominant non-parietal $TcO_4^-$ secretion in the fasting state and dominant parietal $TcO_4^-$ secretion in the stimulated state.

• Transactions on Electrical and Electronic Materials
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• v.16 no.4
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• pp.183-186
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• 2015

This research investigates the impact of charge spreading on the data retention of three-dimensional (3D) silicon-oxide-nitride-oxide-silicon (SONOS) flash memory where the charge trapping layer is shared along the cell string. In order to do so, this study conducts an electrical analysis of the planar SONOS test pattern where the silicon nitride charge storage layer is not isolated but extends beyond the gate electrode. Experimental results from the test pattern show larger retention loss in the devices with extended storage layers compared to isolated devices. This retention degradation is thought to be the result of an additional charge spreading through the extended silicon nitride layer along the width of the memory cell, which should be improved for the successful 3-D application of SONOS flash devices.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.4
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• pp.579-582
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• 1989

Previous experiments have shown that aqueous sodium silicate ingested in drinking water may modify the gastrointestinal uptake and(or) tissue retention of certain trace elements, including heavy metals. The present experiment tested, with a mineral balance trial using sheep, the hypothesis that dietary silicic acid could modify uptake, retention and(or) biological effects of dietary Cd. Twenty-four wethers were fed a fibrous diet of ground alfalfa hay and cottonseed hulls to which either 0 or 150 ppm Cd was added as $CdCl_2$ and 0, .5 or 1% silicic acid (as dry matter of the diet). Body weight, feed intake, excretion of urine (volume) and feces (weight), digestibility of dry and organic matter, retention of nitrogen, and packed cell volumes of blood were not affected by either Cd or silicic acid (P<.10). Cadmium decreased (P<.05) Ca retention and increased (P<.01) Mg retention. Silicic acid decreased (P<.05) K retention. Silicic acid failed (P<.01) to modify the retention of added dietary Cd. Body retention of K, Mn and Ni in response to silicic acid varied with Cd levels. If Cd is interfering with mineral retention, silicic acid may be effective in preventing this interference.

• Animal cells and systems
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• v.7 no.4
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• pp.303-307
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• 2003

The aim of this study is to investigate whether alcohol alters learning and memory processes pertaining to emotional and spatial factors using the active avoidance and T-maze task in zebrafish. In the active avoidance task, zebrafish were trained to escape from one compartment to another to avoid electric shocks (unconditioned stimulus) following a conditioned light signal. Acquisition of active avoidance task appeared to be normal in zebrafish that were treated with 1% alcohol for 30 min for 17 days until the end of the behavioral test, and retention ability of learned behavior, tested 2 days later, was the same as control group. In the T-maze task, the time to find a reservoir was compared. While the latency was similar during the 1 st training session between control and alcohol-treated zebrafish, it was significantly longer in alcohol-treated zebrafish during retention test 24 h later. Furthermore, when alcohol was treated 30 min after 2nd session without prior treatment, zebrafish demonstrated similar retention ability compared to control. These results suggest that chronic alcohol treatment alters spatial learning of zebrafish, but not emotional learning.

• The Journal of Korean Academy of Prosthodontics
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• v.22 no.1
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• pp.23-32
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• 1984

The effects between preexisting four types and one that author had designed of posterior palatal seal on the retention of denture base were compared and observed from six systemically healthy edentulous subjects. Using one without posterior palatal seal as the control, the retention of each type was measured and analyzed six times with cantilever type Load cell after adaptation of denture base, which were constructed with usual manner. The following results wear obtained. 1. Morphological and positional changes of posterior palatal seal effected on denture retention. 2. No specific type showed most desirable effect in every experimental subject. 3. Experimental subject I, II, VI showed higher retention on the control in every type. 4. In five types of posterior palatal seal, for subject III, VI F types and for subject II, V C types were most effective. 5. In each experimental subject F type showed higher retention than the control.

• KSBB Journal
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• v.9 no.2
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• pp.230-237
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• 1994

Spin-filters are used as cell separation devices for achieving high cell density and high productivity in animal cell culture. We have proposed a model for the cell growth in a spin-filter perfusion culture and examined the effects on cell growth by several parameters including ammonia inhibition, specific growth rate, specific feeding rate, and cell retention. Results from computer simulation and sensitivity analysis indicate that the cell retention affects the cell growth mostly while there is a significant inhibition on cell growth by the ammonia accumulated during the culture. The specific feeding rate has minimal effects on cell growth, which is consistant with the fact that the cell growth with a step feeding is quite similar to that with a continuous feeding.