• The Journal of Korean Physical Therapy
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• 제20권4호
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• pp.15-20
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• 2008

Purpose: We investigated the effects of physical practice, mental practice, and cross education using serial reaction time (SRT). We recruited 21 right-handed healthy males and females who gave consent and had no clinical history for their upper limbs. Methods: The subjects were divided into three groups; actual practice (n=7), mental practice (n=7), and controls (n=7), who performed actual training, mental training, or no intervention respectively for three weeks. Super lab 4.0 displayed four symbols on the monitor and subjects pushed on the matching button, with reaction time assessed pre- and post-intervention. Results: Reaction time was significantly lower after actual or mental practice (p<0.05). Actual practice also decreased left hand reaction time. Conclusion: Actual practice and mental practice can improve motor learning, but mental practice is not sufficient for cross education.

• The Journal of Korean Physical Therapy
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• 제26권4호
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• pp.234-239
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• 2014

Purpose: The purpose of this study is to use P300 latency to determine whether methods of motor learning in terms of massed and distributed practice can affect motor sequential learning in healthy adults. Methods: Twenty-four healthy subjects participated in this study. They were randomly allocated into three groups: a 10 minute, a 12 hour, and a 24 hour group. In the SRT task, eight numbers were adopted as auditory stimuli. During an experiment, participants were instructed to press the matching key as quickly and accurately as possible when one of the eight numbers was presented randomly. The subjects practiced for three sessions, each of which comprised five blocks of 40 serial reaction time tasks. While they practiced during these three sessions, P300 latency was measured. The data were analyzed using ANCOVA. Results: The P300 latency of Fz, Cz, and Pz decreased in all groups except for the Fz area of the 10 min group. Overall, the P300 latency of the 10 min group showed a smaller decrease compared with the 12 hr and 24 hr groups. Statistically, no significant differences in the Fz and Cz areas were observed among the three groups. The P300 latency in the Pz area of the 10 min group showed a significantly smaller decrease compared with the other groups. Conclusion: These findings suggest that short-term sequential motor training can alter brain functions such as the P300 latency. We also found that better acquisition of a motor skill was obtained with distributed practice of a task than with massed practice.

• 상하수도학회지
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• 제17권4호
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• pp.550-558
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• 2003

Digestion of primary sludge was conducted to evaluate the effects of reactor configuration using UAD, CUAD, TPAD, and semi-continuos CSTR. Highest VSS reduction and gas production were obtained in CUAD at all HRT. More efficient digestion was accomplished in upflow digesters compared to TPAD and CSTR. Higher thickening of solids in reactor and longer solids retention were main reasons for the enhanced digestion in CUAD and UAD. Performance based on the SRT of CUAD was nearly identical to that of UAD. However, those of TPAD and CSTR were lower than that of CUAD. Particulate and soluble organics in upflow reactors were well adsorbed due to secreted extracellular polymeric substances from the sludge granules. These might result in close proximity of microorganisms and substrates and enhanced hydrolysis. Additionally, diverse anaerobic microorganisms and neutral pH in upflow reactor could induce more activity of hydrolytic enzymes and sludge granules might offer lower thermodynamic energy state. While, excessive mixing in CSTR could break conglomerates of enzymes and substrates into fine particles, which resulted in lowered hydrolysis. Low pH level in acid fermenter of TPAD lowered hydrolysis of the particulate substrates.

• 미생물학회지
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• 제45권2호
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• pp.112-118
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• 2009

질소제거 하수고도처리공정에서 암모니아산화균은 질소제거에 핵심 역할을 하는 독립영양세균이다. 하수처리 생물반응기에는 다양한 암모니아산화균이 서식하며 군집조성도 시간에 따라 변화한다. 본 연구에서는 생물반응기의 운전인자 및 환경조건이 암모니아산화균 군집구조의 조성과 다양성에 영향을 미친다는 가설을 설정하였다. 이 가설을 검증하기 위해 질산화 반응이 활발한 포항, Palo Alto, Nine Springs, Marshall 하수처리장 활성슬러지 생물반응기로부터 암모니아산화균의 ammonia monooxygenase subunit A 유전자 clone library를 제작하였다. 하수처리 생물반응기에는 Nitrosomonas europaea, N. oligotropha, N.-like, Nitrosospira lineage에 속하는 암모니아산화균이 주로 발견되었으며, N. communis, N. marina, N. cryotolerans lineage에 속하는 암모니아산화균은 주종을 이루지 못했다. 암모니아산화균 군집조성은 하수처리장별로 차이를 보였는데, 포항, Palo Alto, Marshall 하수처리장에서는 N. oligotropha lineage에 속하는 암모니아산화균이 가장 빈번히 발견되었고, Nine Springs 하수처리장에서는 N. europaea lineage에 속하는 암모니아산화균이 주종을 이루었다. 한편, 암모니아산화균 군집조성과 생물반응기 운전인자(HRT, SRT, MLSS) 및 환경조건(온도, pH, COD, $NH_3$, $NO_3{^-}$)의 연관성은 다변수 통계분석법인 Redundancy Analysis 방법을 이용하여 분석하였다. 그 결과, 생물반응조의 COD와 $NO_3{^-}$ 농도가 하수처리 생물반응기에서 암모니아산화균 군집구조를 결정하는 통계학적으로 유의한 변수로 나타났다.

• 한국습지학회지
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• 제21권4호
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• pp.251-256
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• 2019

상수원의 상류 및 인근 지역의 경우, 개발 제한으로 인해 상대적으로 하수도 보급률이 낮은 지역이 많다. 이는 지속적으로 상수원 오염에 영향 미치며 이를 방지하기 위한 방안으로 하수도 보급 및 기존 시설의 개선 등의 방안이 제시되고 있다. 본 연구에서는 안동댐과 임하댐 상류에 위치하고 있으며, 선회와류식 SBR공법이 도입된 A하수처리장 모델링을 통해 동절기 마을하수도 방류수 수질 개선 방안을 마련하기 위한 연구를 실시하였다. 5년(2012년 ~ 2016년)간의 운전자료를 바탕으로 모델 구축·검증을 실시하였다. 모델링 결과, SRT 조절을 통해 동절기 방류수 수질 개선이 가능할 것으로 분석되었으며, 각 방류수 수질 기준 별 개선 효과는 BOD 1.8%, COD 54.5%, SS 4.3%, T-N 0.8%, T-P 7.7%로 나타났다. 본 연구를 통해 도출된 동절기 하수처리장 방류수 수질 개선을 위한 방안은 유사한 공법이 도입된 하수처리장 및 마을하수도의 운영 개선방안으로 활용될 수 있을 것으로 판단된다.

• 한국물환경학회지
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• 제25권5호
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• pp.704-712
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• 2009

Advanced Phase Isolation Ditch (APID) process was studied to develop economic retrofitting technology, for the plants where retrofitting of common activated sludge process is required. In this study, to evaluate and monitor the effluent water quality ($BOD_5$, SS, T-N, and T-P) and operating conditions (Influent, SVI, SRT, and HRT) as process capable and stable parameters for treating municipal wastewater, a demonstration plant was installed and operated in the existing sewage treatment plant of P city. During this study, the average effluent $BOD_5$, SS, T-N, and T-P concentrations were 7.7, 5.6, 10.8, and 1.6 mg/L. Trend analysis of influent $BOD_5$, SS, T-N, and T-P in APID process were illustrated that APID process need for more strong APID process management on the winter session, such as developing new intermediated aeration mode, operating methods, and managements strategy. At the application of control chart, the signal of uncommon effects at APID process was determined much higher existing control chart tntr conventional control chart in this study. These results indicate that conventional control chart has been collected and determined cleary signal at only stable situation. Therefore, newly developed APID process of dynamic control chart can be one of the useful tool for monitoring and management process.

• 상하수도학회지
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• 제26권6호
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• pp.897-905
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• 2012

Based on the activated sludge model, a simple aerobic digestion model which represents the aerobic sludge digestion by sequencing batch reactor(SBR) equipped with ultrasonicator was composed and performed in this study. The results are as follows. Aerobic digestion efficiency can be increased by adopting ultrasonic pretreatment. For the 5 days of SRT, 24 % of particulate component is predicted to be removed by ultrasonic pretreatment and aerobic digestion. This is 7 %p higher than that of conventional aerobic digestion. A Hybrid SBR aerobic digestion combined with ultrasonication shows higher digestion efficiency than aerobic digestion and ultrasonic pretreatment system. In case of this hybrid system, the digestion efficiency was predicted up to 49 % when the ultrasonication was performed every 2 hours, repeatedly. However, excessive treatment like every hours of ultrasonication in an aerobic digestion process results in adverse effect on TCOD removal because biomass disintegrated completely and the solubilized COD can not be used for the biomass synthesis again.

• Environmental Engineering Research
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• 제19권4호
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• pp.387-393
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• 2014

The purpose of this study is to evaluate integrated anaerobic hydrogen fermentation and membrane bioreactor (MBR) for on-site domestic wastewater treatment and resource recovery. A synthetic wastewater (COD 17,000 mg/L) was used as artificial brown water which will be discharged from urine diversion toilet and fed into a continuous stirred tank reactor (CSTR) type anaerobic reactor with inclined plate. The effluent of anaerobic reactor mixed with real household grey water (COD 700 mg/L) was further treated by MBR for reuse. An optimum condition maintained in anaerobic reactor was HRT of 8 hrs, pH 5.5, SRT of 5 days and temperature of $37^{\circ}C$. COD removal of 98% was achieved from the overall system. Total gas production rate and hydrogen content was 4.6 L/day and 52.4% respectively. COD mass balance described the COD distribution in the system via reactor byproducts and effluent COD concentration. The results of this study asserts that, anaerobic hydrogen fermentation combined with MBR is a potent system in stabilizing waste strength and clean hydrogen recovery which could be implemented for onsite domestic wastewater treatment and reuse.

• The Journal of Korean Physical Therapy
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• 제23권2호
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• pp.31-36
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• 2011

Purpose: We investigated the effects of physical practice, mental practice, and cross education using serial reaction time (SRT) in the non-dominant left arm of right-handed individuals. Methods: Subjects were divided into three groups; physical practice (n=8), mental practice (n=8) and controls (n=8). They did, respectively, physical training or mental training, or had no intervention for three weeks. Super lab 4.0 displayed four symbols on the monitor and subjects were asked to push the matching button. Reaction time was assessed pre- and post-intervention. Results: Reaction time was significantly lower after physical practice (p<0.05), but mental practice did not significantly lower reaction time? in the left hand. Also, reaction time was not significantly lower after physical practice or mental practice in the right hand. Conclusion: Physical practice can improve motor learning, but mental practice is not sufficient. Also, neither physical practice nor mental practice is sufficient for cross education from the nondominant to the dominant arm.

• Membrane and Water Treatment
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• 제3권2호
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• pp.133-140
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• 2012

The overall performance of BNR-MBR, so-called Anoxic-Anaerobic-Aerobic Membrane Bioreactor ($A^3$-MBR), developed for nutrient removal was studied to determine the efficiencies and mechanisms under different solid retention time (SRT). The reactor was fed by synthetic high-rise building wastewater with a COD:N:P ratio of 100:10:2.5. The results showed that TKN, TN and phosphorus removal by the system was higher than 95%, 93% and 80%, respectively. Nitrogen removal in the system was related to the simultaneous nitrification-denitrification (SND) reaction which removed all nitrogen forms in aerobic condition. SND reaction in the system occurred because of the large floc size formation. Phosphorus removal in the system related to the high phosphorus content in bacterial cells and the little effects of nitrate nitrogen on phosphorus release in the anaerobic condition. Therefore, high quality of treated effluent could be achieved with the $A^3$-MBR system for various water reuse purposes.