• 제목/요약/키워드: energy deficit

검색결과 80건 처리시간 0.023초

남해연안 패류양식장의 부영양화 특성 (Eutrophication Characteristics in the Shellfish Farms, the Southern Coastal Sea of Korea)

  • 이찬원;권영택;부민호;권혁보;양기섭
    • 한국해양환경ㆍ에너지학회지
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    • 제3권3호
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    • pp.24-33
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    • 2000
  • 우리나라 남해연안의 해양수산자원과 경관은 생태학적인 관점에서뿐만 아니라 경제적으로도 매우 중요하다. 밀식 등 과다한 양식과 하ㆍ폐수의 유입으로 이 해역의 부영양화 현상은 더욱 심각하게 되었다. 본 연구는 1998년부터 1999년까지 여름과 겨울로 구분하여 채취한 해수와 퇴적물의 분석결과로부터 남해연안의 부영양화 상태를 파악하였고, 퇴적물 오염정도, 퇴적물로부터 의 영양염류 용출과 산소소비량을 측정하였다. 또한 양식장 자가오염의 주원인중의 하나인 양식장의 부착생물에 의한 배설물량을 측정하였다. 양식장의 해수의 영양염류 농도는 일반해양보다 대체적으로 높게 나타났다. 양식장에서 채취된 여름의 퇴적물 중 COD와 총인의 농도가 겨울의 퇴적물보다 높은 경향을 보여주었다. 우리나라 남해연안의 패류양식장 퇴적물은 부영양화 물질과 저산소층 수괴의 주요 오염원으로 작용하고 있음을 알 수 있었다.

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마산ㆍ창원 하수종말 처리장의 해양방류 처리수에 대한 초기ㆍ근역 희석연구(I) (A Study on Initial and Near-Field Dilution at the Ocean Outfall of Masan-Changwon Municipal Wastewater Treatment Plant)

  • 강시환;유승협;오병철
    • 한국해양환경ㆍ에너지학회지
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    • 제2권2호
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    • pp.60-69
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    • 1999
  • 본 논문에서는 국내 최초로 수중확산관을 통해 하ㆍ폐수 1차 처리수를 해양방류하고 있는 마산ㆍ창원 하수종말처리장의 해양방류수에 대한 초기ㆍ근역 희석률을 현장관측과 CORMIX 모형계산을 통해 비교 검토하였다. 수심 15m 내외의 방류수역에서 수온약층이 수심 4m~6m에서 형성된 1998년 하계에 관측된 염분도로부터 희석률을 구하였으며, 또한 해수밀도의 수직 분포와 해류자료를 입력하여 모형으로부터 하 폐수 플륨의 이동확산 양상과 초기희석률을 계산하였다. 방류지점의 관측된 염분도 분포로부터 구한 희석률은 32~48이며, 모형에 의해 계산된 초기ㆍ근역 희석률은 29~43으로 두 결과 모두 매우 낮은 하계 소조시의 희석률을 보이고 있다. 이는 조류가 약한 소조기의 정체 시에는 방류수에 포함된 오염물질로 인해 해양방류수역의 수질오염이 더욱 가중될 수 있음을 보여준다.

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마산ㆍ창원 하수종말 처리장의 해양방류 처리수에 대한 초기ㆍ근역 희석연구(II) (Initial and Near-field Dilution at the Ocean Outfall of Masan-Changwon Municipal Wastewater Treatment Plant(II))

  • 강시환;유승협;오병철;박광순
    • 한국해양환경ㆍ에너지학회지
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    • 제3권1호
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    • pp.35-44
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    • 2000
  • 1999년 2월에 관측한 수온 및 염분도 분포로부터 마산ㆍ창원 하수종말처리장의 해양 수중방류수에 대한 동계의 근역희석률을 산정하였다. 소조기의 약한 주변유속과 수온약층에 의해 하수플륨이 포착되어 희석률이 30~40정도로 저조했던 하계의 경우와는 달리 동계 소조기의 경우에는 주변해수의 수직적 등밀도혼합이 전 층에서 형성되어 하수플륨이 수표면까지 상승하며 희석률도 90~130정도로 훨씬 큰 것으로 나타났다. CORMIX2 모형의 모의결과에서도 소조기의 약한 유속(Ua=6.0cm/s)의 경우 동계 희석률이 하계 희석률보다 약 3배 정도 증가하였으며 대조기의 강한 유속(Ua=15.5cm/s)의 경우에는 두 계절의 희석률 차이가 30%정도로 미미하였다. 이는 수중방류 하수의 근역희석 및 혼합과정이 주변해수의 밀도성층 효과보다는 유동성분에 더 큰 영향을 받기 때문인 것으로 사료된다.

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상용 CFD 프로그램을 이용한 풍력터빈 축소모델 출력계수 검증 및 후류 해석 (Validation of Power Coefficient and Wake Analysis of Scaled Wind Turbine using Commercial CFD Program)

  • 김병수;백인수;유능수
    • 한국태양에너지학회 논문집
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    • 제35권1호
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    • pp.35-43
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    • 2015
  • A numerical simulation on the wake flow of a wind turbine which is a scaled version of a multi-megawatt wind turbine has been performed. Two different inlet conditions of averaged wind speed including one below and one above the rated wind speed were used in the simulation. Steady-state pitch angles of the blade associated with the two averaged wind speeds were imposed for the simulation. The steady state analysis based on the Reynolds averaged Navier-Stokes equations with the method of frame motion were used for the simulation to find the torque of the rotor and the wake field behind the wind turbine. The simulation results were compared with the results obtained from the wind tunnel testing. From comparisons, it was found that the simulation results on the turbine power are pretty close to the experimental values. Also, the wake results were relatively close to the experimental results but there existed some discrepancy in the shape of velocity deficit. The reason for the discrepancy is considered due to the steady state solution with the frame motion method used in the simulation. However, the method is considered useful for solutions with much reduced calculation time and reasonably good accuracy compared to the transient analysis.

주의력결핍 과잉행동장애(ADHD) 한의 변증 설문지 개발 연구 (Development of Pattern Identification Questionnaire for Attention-Deficit/Hyperactivity Disorder (ADHD) in Korean Medicine)

  • 안윤영;정민정;김미연;김락형
    • 동의신경정신과학회지
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    • 제30권1호
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    • pp.1-11
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    • 2019
  • Objectives: Attention-Deficit/Hyperactivity Disorder (ADHD) is characterized by a persistent pattern of inattention and/or hyperactivity impulsivity that interferes with function or development in children. In traditional Korean medicine (TKM) and traditional Chinese medicine (TCM), ADHD is classified by several patterns based on symptoms and signs. However, currently, there is no objective diagnostic tool for ADHD in traditional medicine. The objective of this study was to develop the Pattern Identification Questionnaire for ADHD (parents-survey style) to be used in Korean medicine, through a literature review and consultation with groups of experts. Methods: The types of pattern identifications of ADHD mentioned in 13 pieces of Korean and Chinese literatures and their symptoms and signs were analyzed. The advisory committee (15 Neuropsychiatrist and 11 Pediatrist in Korean Medicine) assessed the appropriateness of the literature selection and the types of pattern identification selection and their symptoms and signs, and weighed the significance of the symptoms and signs. The Pattern Identification Questionnaire for ADHD was developed using the calculated weights by evaluated significance. The translation of symptoms and signs to the Korean language was achieved through consultation with expert translators. Results: 1. Four pattern identification types and their symptoms and signs were selected according to frequency of appearance in the Korean and Chinese literatures, and were reviewed by the advisory committee: Kidney yin deficiency and liver yang ascendant hyperactivity (腎虛肝亢), Dual deficiencies in the heart and spleen (心脾兩虛), Phlegm-fire harassing the heart (痰火擾心), and Spleen weakness and liver energy preponderance (脾虛肝旺). 2. The weights of all the symptoms and signs in the four patterns were calculated using the means and standard deviations of the symptoms and signs' importance that were obtained from specialists' significance weighting. 3. The Pattern Identification Questionnaire for ADHD (parents-survey style) in Korean medicine composed of 38 questions was suggested. Conclusions: Using a review of the literature and expert advice, Pattern Identification Questionnaire for ADHD (parents-survey style) in Korean medicine was developed. Further clinical study is required to develop a final version of the questionnaire through the evaluation of reliability and validity.

위성기반 증발산량 및 토양수분량 산정 국내 연구동향 (Research Status of Satellite-based Evapotranspiration and Soil Moisture Estimations in South Korea)

  • 최가영;조영현
    • 대한원격탐사학회지
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    • 제38권6_1호
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    • pp.1141-1180
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    • 2022
  • 최근 수문 및 수자원 분야에서 위성영상의 활용성이 높아짐에 따라 관련 전용 위성 개발연구와 연계하여 위성을 활용한 증발산량과 토양수분량 산정 연구의 필요성이 강조되고 있다. 본 연구에서는 이러한 위성을 기반으로 증발산량 및 토양수분량의 국내 연구현황과 그 산정 방법론을 조사하여 현재까지의 연구동향을 파악하고자 하였다. 국내 연구현황을 세부 방법론 별로 살펴본 결과 일반적으로 증발산량의 경우는 Surface Energy Balance Algorithm for Land (SEBAL), Mapping Evapotranspiration with Internalized Calibration (METRIC)과 같은 에너지수지 기반 모형과 Penman-Monteith (PM) 및 Priestley-Taylor (PT) 산출식을 기반으로 산정되었으며, 토양수분량의 경우 능동형(AMSR-E, AMSR2, MIRAS, SMAP) 및 수동형(ASCAT, SAR)와 같은 마이크로파 센서를 통한 산정이 주를 이루었다. 통계적 측면에서는 증발산량 및 토양수분량 공통적으로 회귀식 및 인공지능을 이용한 산출사례를 찾을 수 있었다. 또한 위성기반 자료들을 이용한 Evaporative Stress Index (ESI), Temperature-Vegetation Dryness Index (TVDI), Soil Moisture Deficit Index (SMDI) 등의 다양한 지표를 산정하여 가뭄 특성파악에 적용한 연구 사례도 다수 있었으며, 지표모형(Land Surface Model, LSM)을 기반으로 하여 위성 다중센서에서 얻을 수 있는 주요 자료들을 활용해 증발산량과 토양수분량의 수문순환인자를 산출하기도 하였다. 본 논문에서는 이렇게 기존 연구사례 조사 및 내용파악 과정을 통해 위성을 활용한 주요 세부 방법론을 비교·검토 제시함으로써 관련 연구분야 기준 참고자료로의 활용 및 향후 위성기반 관련 수문순환 자료 산출 고도화 연구의 초석을 다지고자 한다.

Effects on Performance of Sulla and/or Maize Silages Supplements for Grazing Dairy Cows

  • Chaves, Alexandre V.;Woodward, S.L.;Waghorn, G.C.;Brookes, I.M.;Burke, J.L.
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권9호
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    • pp.1271-1282
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    • 2006
  • The objective of this study was to investigate the effects of either maize or sulla silage supplementation to grazing dairy cows in summer. Forage mixtures used in the four week trial were based on previous experimental results but inclusion of rumen fistulated cows in five treatments enabled rumen sampling and use of in sacco incubations to determine the diet effects on digestion kinetics. Sulla and maize silages were used to supplement pasture and to meet minimum requirements for dietary protein concentration. Five groups of ten cows were grazed on a restricted daily allowance of 18 kg dry matter (DM) pasture/cow to simulate a summer pasture deficit, and four of these five groups received an additional 6 kg DM $cow^{-1}d^{-1}$ of silage (sulla, maize, or sulla and maize silages). A sixth group was given a relatively unrestricted (38 kg DM $cow^{-1}d^{-1}$) pasture allowance. The silage mixtures and pasture were incubated in sacco during the final week of the trial. The pasture was of high nutritive value and not typical of usual summer conditions, which favoured a response to quantity rather than quality of silage supplements. There was no difference in cow performance with the four silage supplements and the low milk solids (MS) production (about 1.0 kg $MS\;d^{-1}$) relative to full pasture (1.3 kg $MS\;d^{-1}$) showed the principal limitation to performance was dry matter intake. Milk composition was not affected by silage type and the low level of pasture substitution (0.29) suggested metabolizable energy (ME) was the principal limitation to performance. Samples of rumen liquor and in sacco data demonstrated significant effects of supplement; DM degradation rates (k) was highest ($0.084h^{-1}$) when cows were fed 6 kg sulla silage whereas diets with a high proportion of maize silage were slowly degraded (p<0.01).

경남 일부 지역 노임의 영양실태조사-생활습관, 식행동 및 영양소 섭취 실태를 중심으로- (Nutrition Status of the Rural Elderly Living in Kyungnam-Focusing on Health-Related Habits , Dietary Behaviors of Nutrient Intakes-)

  • 박미경;이경혜;윤현숙
    • 대한지역사회영양학회지
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    • 제6권3호
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    • pp.527-541
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    • 2001
  • This study was conducted to provide basic information on the nutritional status and health status of the rural elderly. The food intake, food habits and others health related factors were surveryed by interview method. The subjects was 200 people(71 male, 129 female) aged over 65 year in the Han-an area. The obtained results as follows; Their average age is 73.5$\pm$5.6. Mean height and weight of elderly men were 163 cm and 58.1 kg. respectively and 148.7 cm and 50.0 kg for women. The regularity appetite and frequency of eating snacks and eating out were higher in men than in women. The favorite snacks for men were alcohol fruit coffee and for women was fruit, candy, cookies and coffee. The daily alcohol drinking and smoking ration were 50.0%, 60.6% for men, respectively and 14.0%, 24.8 % for women. The nutritional intake ratio to RDA of men was significantly higher than women. Especially, the intakes of energy, Ca, Vit.A, Vit B$_1$, Vit B$_2$ niacin were extremely low in women. The frequency of alcohol intake was related to nutrient intake of women . There was a negative correlation between age. smoking rate and the nutritional intake. The pocket money, weight height appetite, and frequency of snacks showed a positive relation to nutritional intake. In conclusion the study shows that gender did influence food intake in the elderly, Food intake of women was extremely in deficit, because the most elderly rural women live alone. For successful aging. a program for rural elderly is needed on the govermment level, i.e actions to provide minimum economic life, food delivery and psychological/ physical health care through regional pubilc health centers.

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Hybrid Reference Function for Stable Stepwise Inertial Control of a Doubly-Fed Induction Generator

  • Yang, Dejian;Lee, Jinsik;Hur, Kyeon;Kang, Yong Cheol
    • Journal of Electrical Engineering and Technology
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    • 제11권1호
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    • pp.86-92
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    • 2016
  • Upon detecting a frequency event in a power system, the stepwise inertial control (SIC) of a wind turbine generator (WTG) instantly increases the power output for a preset period so as to arrest the frequency drop. Afterwards, SIC rapidly reduces the WTG output to avert over-deceleration (OD). However, such a rapid output reduction may act as a power deficit in the power system, and thereby cause a second frequency dip. In this paper, a hybrid reference function for the stable SIC of a doubly-fed induction generator is proposed to prevent OD while improving the frequency nadir (FN). To achieve this objective, a reference function is separately defined prior to and after the FN. In order to improve the FN when an event is detected, the reference is instantly increased by a constant and then maintained until the FN. This constant is determined by considering the power margin and available kinetic energy. To prevent OD, the reference decays with the rotor speed after the FN. The performance of the proposed scheme was validated under various wind speed conditions and wind power penetration levels using an EMTP-RV simulator. The results clearly demonstrate that the scheme successfully prevents OD while improving the FN at different wind conditions and wind power penetration levels. Furthermore, the scheme is adaptive to the size of a frequency event.

Neuroprotective Effects of AMP-Activated Protein Kinase on Scopolamine Induced Memory Impairment

  • Kim, Soo-Jeong;Lee, Jun-Ho;Chung, Hwan-Suck;Song, Joo-Hyun;Ha, Joohun;Bae, Hyunsu
    • The Korean Journal of Physiology and Pharmacology
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    • 제17권4호
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    • pp.331-338
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    • 2013
  • AMP-activated protein kinase (AMPK), an important regulator of energy metabolism, is activated in response to cellular stress when intracellular levels of AMP increase. We investigated the neuroprotective effects of AMPK against scopolamine-induced memory impairment in vivo and glutamate-induced cytotoxicity in vitro. An adenovirus expressing AMPK wild type alpha subunit (WT) or a dominant negative form (DN) was injected into the hippocampus of rats using a stereotaxic apparatus. The AMPK WT-injected rats showed significant reversal of the scopolamine induced cognitive deficit as evaluated by escape latency in the Morris water maze. In addition, they showed enhanced acetylcholinesterase (AChE)-reactive neurons in the hippocampus, implying increased cholinergic activity in response to AMPK. We also studied the cellular mechanism by which AMPK protects against glutamate-induced cell death in primary cultured rat hippocampal neurons. We further demonstrated that AMPK WT-infected cells increased cell viability and reduced Annexin V positive hippocampal neurons. Western blot analysis indicated that AMPK WT-infected cells reduced the expression of Bax and had no effects on Bcl-2, which resulted in a decreased Bax/Bcl-2 ratio. These data suggest that AMPK is a useful cognitive impairment treatment target, and that its beneficial effects are mediated via the protective capacity of hippocampal neurons.