• Journal of Soil and Groundwater Environment
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• v.16 no.2
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• pp.52-60
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• 2011

Although facilities for the passive treatment of AMD (Acid Mine Drainage) are currently operating in Korea, their removal efficiency for heavy metals is relatively low in average (only 80%). Passive treatment system is composed of oxidation tank, SAPS (Successive Alkalinity Producing System), and wetland. In the treatment system adopted in korea, SAPS (Successive Alkalinity Producing System) plays a major role to remove about 65% of heavy metals through a precipitation. However, the efficiency of SAPS is limited due to the use of mushroom compost (MC) as a organic material and of limestone as a neutralizer. Therefore, this research was performed to search for alternative organic materials through the field test. We tested two types of mixed organic materials: 1) cow manure and spent oak (herein, CO) and 2) cow manure and sawdust (herein, CS). For comparison mushroom compost (herein, MC) was also tested. The result showed that the average Fe removal efficiency was 91.38% with CO, 85.19% with CS, and 91.58% with MC. Thus, CO can be effectively used as an alternative of MC in the SAPS system for heavy metals removal.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.2
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• pp.193-201
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• 2008

In edentulous mandible, implant supported overdenture was considered as a first treatment option. In case of a implant supported telescopic overdenture, sufficient inter-arch space needs for arrangement of artificial teeth and attachment. Passive fit of the implant prosthesis is important factor for preventing mechanical failure. Gold Electroforming System is particularly useful to achieve a passive fit of telescopic attachment and results in precision marginal fit and the small thickness of the coping provides optimal space for narrow inter-arch space. This article presents that application of Gold Electroforming System can provide excellent esthetics and function on four-implant supported telescopic overdenture.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.270-270
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• 2007

전자 산업의 발달로 인해 전자기기에 소형화, 경량화 및 다기능화가 요구되면서 민쇄회로기판(PCB)에도 고밀도화, 고집적회가 필요하게 되었다. 이에 따라 embedded passive 기술을 이용하여 기판 내부에 가능한 많은 수동소자들을 실장시키려는 노력이 진행되어지고 있다. 가장 수요가 많은 capacitor의 경우 부피와 전기적 특성 측면에서 내장 효과가 가장 큰 passive 소자에 해당한다. 본 연구에서는 내장형 capacitor의 유전재료로서 중요한 $BaTiO_3$ powder를 filler로 사용하여 epoxy/BT 복합체에서 filler의 분율에 따른 유전상수률 측정하고, filler의 열처리에 따른 유전상수의 변화를 관찰하였다. 그러고 이들 복합체의 mixing rule과 미세구조 관찰을 통하여 기판용 RCC 소재로서의 적용성을 평가하고자 하였다.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.3
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• pp.193-200
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• 2004

The Active Constrained Layer Damping(ACLD) combines the simplicity and reliability of passive damping with the low weight and high efficiency of active control to attain high damping characteristics. The proposed ACLD treatment consists of a viscoelastic damping which is sandwiched between an active piezoelectric layer and a host structure. In this manner, the smart ACLD consists of a Passive Constrained Layer Damping(PCLD) which is augmented with an active control in response to the structural vibrations. The arc type shell model is introduced to describe the interactions between the vibrating host structure, piezoelectric actuator and viscoelastic damping. The system is modeled by applying ARMAX model and changing a state-space form through the system identification method. An optimum control law for the piezo actuator is obtain by LQR(Linear Quadratic Regulator) method. The performance of the ACLD system is determined and compared with PCLD in order to demonstrate the effectiveness of the ACLD treatment. Also, the actuation capability of a piezo actuator is examined experimentally by varying thickness of viscoelastic material(VEM).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.1032-1038
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• 2002

The Active Constrained Layer Damping(ACLO) combines the simplicity and reliability of passive damping with the low weight and high efficiency of active control to attain high damping characteristics. The proposed ACLD treatment consists of a viscoelastic damping which is sandwiched between an active piezoelectric layer and a host structure. In this manner, the smart ACLD consists of a Passive Constrained Layer Damping(PCLD) which is augmented with an active control in response to the structural vibrations. The Arc type shell model is introduced to describe the interactions between the vibrating host structure, piezoelectric actuator and visco damping, The system is modeled by applying ARMAX model and changing a state-space form through the system identification method. An optimum control law for piezo actuator is obtain by LQR(Linear Quadratic Regulator) Method. The performance of ACLD system is determined and compared with PCLD in order to demonstrate the effectiveness of the ACLD treatment, Also, the actuation capability of a piezo actuator is examined experimentally by using various thickness of Viscoelastic Materials(VEM).

• Journal of Oriental Neuropsychiatry
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• v.28 no.2
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• pp.123-136
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• 2017

Objectives: The objective of this study is to investigate the anti-amnesic effects of AR, Aucklandiae Radix, ground powder on scopolamine (Sco)-induced memory impairment in mice (C57BL/6) through its favorable acetylcholine (ACh) and acetylcholinesterase (AChE) activity, Choline acetyltransferase (ChAT) mRNA expression, and antioxidant effect. Methods: Six groups, a total of 20 intact or 100 Sco treated mice, were selected based on their body weights and were used in this study. Half of the mice in each group were used for the passive avoidance task test and the measurements of hippocampus ACh content, AChE activity and ChAT mRNA expression. The remaining half of the mice in each group were used for the Morris water maze test and cerebral antioxidant defense system measurement. Results: Marked decreases in step-through latency times in the passive avoidance task test and increases in escape latency times in the Morris water maze test were observed with decreases in the hippocampus ACh content and ChAT mRNA expression, and increases in the hippocampal AChE activities, as a result of Sco intraperitoneal treatment, in the present study. In addition, destruction of the cerebral cortex antioxidant defense systems was observed in Sco control mice as compared with intact vehicle control mice. However, 28 days of continuous oral pre-treatment with AR ground powder at doses of 400, 200 and 100 mg/kg markedly and dose-dependently inhibited the Sco treatment-related amnesia. Conclusions: The results prove that oral administration of AR ground powder reduces Sco-induced memory impairment. This is because it can preserve ACh, related to ChAT mRNA expression, cause AChE inhibition, and activate the cerebral antioxidant defense system.

• Journal of Oriental Neuropsychiatry
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• v.30 no.3
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• pp.221-235
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• 2019

Objectives: The purpose of this study was to confirm the anti-amnesic effects of Bunsimgieum (BSGE) through its favorable acetylcholine (ACh) and, acetylcholinesterase (AChE) activity, choline acetyltransferase (ChAT) mRNA expressions, and antioxidant effect on scopolamine (Sco)-induced memory impairment in C57BL/6 mice. Methods: Six groups, a total of 20 intact or 100 Sco-induced mice were used in this study, based on their body weight. Half of each group underwent passive avoidance tests and the measurement of hippocampus AChE activity, ACh content, and ChAT mRNA expression, The remaining half of each group underwent a Morris water-maze test and antioxidant defense system measurement as well. Results: Significant reductions in the step-through latency times from the passive avoidance test and reductions in the escape latency times from the Morris water-maze test were observed with increases of hippocampal AChE activities and, reductions in ACh contents and ChAT mRNA expression in hippocampus, as a result of Sco intraperitoneal treatment, in this study. Additionally, the increases in cerebral cortical MDA levels and, reductions in GSH contents, SOD activities, and CAT activities were demonstrated in the Sco control mice compared with the intact vehicle control mice, respectively. However, 28 days of consecutive oral pre-treatment of BSGE hot water extracts of 400, 200, and 100 mg/kg, respectively, markedly and dose-dependently inhibited Sco treatment-related amnesia. Conclusions: The results demonstrate that the oral administration of BSGE hot water extracts reduces Sco-induced memory impairment, through preserving ACh, related to ChAT mRNA expressions, causes AChE inhibition, and enhances the cerebral antioxidant defense system.

• YAKHAK HOEJI
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• v.39 no.3
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• pp.231-242
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• 1995

Electroconvulsive shock (ECS) increases the activity of acetylchohnesterase and decreases in brain acetylcholine levels. A large amount of free fatty acids accumulated in the brain tissue affects cerebral blood flow, brain edema and inflammation and results in brain injury. The present study examined the effect of docosahexaenoic acid (DHA) and D,L-pyroglutamic acid (D,L-PCA) on the learning and memory deficit using the passive avoidance failure technique and on the change of acetylcholine and choline level in the cerebral cortex of ECS-induced mice. The application of ECS (25mA, 0.5sec) induced a significant decrease in memory function for 30 min. ECS-induced a significant decrease in cortical acetylcholine and choline levels 1 min following the ECS application, which were almost recovered to ECS control level after 30 min. DHA (20 mg/kg, i.p.). administered 24 hr before shock. prevented the ECS-induced passive avoidance failure and the decrease of acetylcholine level 1 min following the ECS application. DHA failed to elicit a change in cortical choline level. DHA did not affect memory function and the cortical Ach and choline level of normal mice. The administration of D,L-PCA (500 mg/kg, i.p.) increased the effect of DHA on memory function and the change of cortical acetylcholine level of ECS induced mice. These results suggest that DHA treatment may be contributed to the prevention against memory deficit, and to the activation of cholinergic system in the ECS induced mice.

• Journal of the Mineralogical Society of Korea
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• v.27 no.2
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• pp.97-105
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• 2014

Artificial precipitation ponds, consisting of three steps of oxidation pond, successive alkalinity producing system (SAPS) and swamp, were constructed for the treatment of the acid mine drainage from the Iwal coal mine. The efficacies of the passive treatment system in terms of neutralization of mine water and removal of dissolved ions were evaluated by the chemical analyses of the water samples. Mine water in the mine adits was acidic, showing the pH value of 2.28-2.42 but the value increased rapidly to 6.17-6.53 in the Oxidation pond. The purification efficiencies for the removal of Al and Fe were 100%, whereas those of $SO_4$, Mg, Ca, and Mn were relatively low of 50%, 40%, 24%, and 59%, respectively. These results indicate a need for application of additional remediation techniques in the passive treatment systems. The precipitates that formed at the bottom of the mine water channels were mainly schwertmannite ($Fe_8O_8(OH)_6SO_4$) and those in the leachate water were 2-line ferrihydrite ($Fe_2O_3{cdot}0.5H_2O$).

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.57-63
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• 2003

Background: Rehmanniae radix preparata is a medicinal herb widely used in Asian countries, to replenish Yin and Vital Essence through strengthen the kidney function. In Oriental Medicine the brain has physiological relationship with the Vital Essence. And central nerve system (CNS) is also refered to as 'Sea of the Vital Essence'. So if the Vital Essence is strong it will nourish the brain and memory will all be keen. The purpose of this study was to investigate the effect of 7 to 14 days treatment with Rehmanniae radix preparata (3.4 g /100 g, per os) on retention performance of rats in a passive avoidance situation. Methods: Male Sprague-Dawley rats were trained on a one-trial passive avoidance task using a two-way shuttle box by giving a foot shock. They were tested for retention of 6h, 24h, 72h, 168h, and 336h after training. Results: Rehmanniae radix preparata treated rats showed a increased performance in retention test as compared to saline at 6hr (P<0.05) and 24hr (P<0.05). Conclusion: These data suggest that Rehmanniae radix preparata treatment can improve memory in the rat.