• 제목/요약/키워드: Intermittent Feeding

검색결과 58건 처리시간 0.032초

간헐 주입 2단(수직 및 수평 흐름) 모래 갈대 인공습지에 의한 생활하수 처리 (Evaluation of Combined Vertical and Horizontal Flow Sand-Filled Reed Constructed Wetland with Intermittent Feeding for Sewage Treatment)

  • 서정윤
    • 한국습지학회지
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    • 제16권2호
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    • pp.261-268
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    • 2014
  • 본 연구의 목적은 직렬연결 2단 수직 및 수평 모래 갈대 인공습지에 생활하수를 간헐적으로 주입하였을 때 각 수질항목별 처리효율을 평가하는 것이다. 하수는 수리학적 부하량 $314L/m^2{\cdot}day$(수직 흐름 인공습지 기준)를 하루 4(10분 동안 주입후 5시간 50분 동안 중단)회 균등하게 간헐적으로 주입하였다. 평가 결과 pH는 유입수(7.27)보다 수직 흐름 인공습지 유출수(5.81)에서 감소하였다가 수평 흐름 인공습지 유출수(6.40)에서 다시 증가하였다. DO의 농도는 유입수에 비하여 유출수에서 높았으며 겨울로 갈수록 증가하였다. 수직 흐름 인공습지의 산소 전달율 (oxygen transfer rate: OTR)은 $58.72gO_2/m^2{\cdot}day$ 그리고 수평 흐름 인공습지의 OTR은 $7.72gO_2/m^2{\cdot}day$이었다. 각 항목별 평균 처리효율은 SS 94.80%, BOD 90.77%, $COD_{Cr}$ 85.87%, $COD_{Mn}$ 87.72%, T-N 64.74%, $NH_4{^+}$-N 86.44%, T-P 87.70%이었다. 유출수중 T-N의 반 정도는 $NO_3{^-}$-N(7.21 mg/L)이었으며 $NO_2{^-}$-N은 평균 0.64 mg/L이었다.

Experimental Study on the Effect of Temporary Clipping on the Histological Changes of the Arterial Walls of Rats

  • 고현송
    • 대한의생명과학회지
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    • 제13권2호
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    • pp.111-117
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    • 2007
  • Temporary occlusion of the parent artery or feeding artery is an useful method in microsurgery for cerebrovascular diseases. The advantages of the temporary clipping for intracranial aneurysm surgery have already been proven by many experimental and clinical reports. Currently, there are two methods of temporary clipping: 1) intermittent clipping, 2) continuous clipping. In many previous studies, the intermittent, repeated clipping technique was reported to reduce ischemic damage to the brain, but it is still debated. On the other hand, a comparison of the histological changes on the arterial wall between each clipping method has not been sufficiently reported yet. So the authors performed experimental temporary clipping on the common carotid and femoral arteries of about 25 rats using the Sugita temporary mini-clip. The specimens were divided into two major groups and seven subgroups: Group I (I-1, I-2, I-3, I-4, intermittent clippings for 5 minutes were done once, twice, three times, and few times), and Group C (C-10, C-15, C-20, continuous clippings for 10, 15, 20 minutes, respectively). The reperfusion time after the temporary clipping was the same as the clipping duration. Under light microscope, the histological findings by Hematoxylin-Eosin staining were examined in all specimens, which were obtained at each time interval after temporary clipping. Then the histological changes of the arterial walls by two different methods were compared with the normal specimen. The results suggest that intermittent temporary clipping is less damaging on the arterial wall than single continuous clipping.

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Monascus anka로부터 유기배양에 의한 적색소의 대량생산 (Red Pigment Overproduction by Fed-Batch Culture of Monascus anka)

  • 김희구;박근태;손홍주
    • 한국식품영양학회지
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    • 제11권6호
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    • pp.617-621
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    • 1998
  • The production of red pigment from glucose by fed-batch culture of Monascus anka was investigated. In batch culture using fermentor, 200 rpm of agitation speed, 1vvm of aeration volume, and 10% (v/v) of inoculum size were optimal, respectively. The red pigment production was increased by removal of wall-attached mycelium. In an intermittent feeding fed-batch culture, dry cell weight increased to 30 g/l, adn the red pigment content reached 350 of absorbance at 495nm. In a continuous feeding fed-batch culture, dry cell weight increased to 22g/l, and the red pigment content reached 190 of absorbance at 495nm.

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볼락, Sebastes inermis 의 섭식상태 (Feeding Ecology of Black Rockfish, Sebastes inermis)

  • 김종관;강용주
    • 한국수산과학회지
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    • 제32권5호
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    • pp.637-641
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    • 1999
  • 본 연구는 볼락, Sebastes inermis의 섭식생태를 파악하기 위하여 경남 사천시 신수도 연안에서 채집된 볼락의 섭식활동 주기와 위내용물을 분석하였다. 어체표본은 1984년 2월부터 1985년 5월사이에 낚시, 자망, 소형기선저인망, 낭장망 등으로서 채집하였다. 볼락의 표본은 0세군부터 4세군까지 채집되었으며, 이들의 주 섭식활동 시간대는 봄, 여름의 경우 이른 아침과 늦은 오후였고, 가을과 겨울에는 특별한 섭식활동 시간대 없이 1$\~$2시간 주기로 간헐적인 섭식활동을 하였다. 이들의 먹이생물은 어류의 연령과 계절에 따라 달랐지만, 주요 먹이생물은 요각류(copepods), 옆새우류(gammarids), 카프렐라류 (caprellids), 생 이류 (carideans), 다모류(polychaees), 단미류 (brachyurans) 등이었다 0세군은 요각류를 주먹이로 섭식하였고, 1세군 이상은 옆새우류를 주 먹이로 이용하였다. 먹이생물의 다양도와 균등도는 어체의 연령이 증가할수록 높았다. 본 종의 섭식기관, 소화기관의 형태, 먹이생물의 종류 등을 고려하였을 때, 볼락은 소형 갑각류를 주 먹이생물로 이용하는 육식성이면서 시각섭식성 식성을 지닌 어류인 것으로 판단되었다.

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유가식 배양공정에 의한 Bacillus thurngiensis의 고농도 포자생산 (High Concentrated Spore Production of Bacillus thuringliensis by Fed-Batch Processes)

  • 박창열;유연우
    • KSBB Journal
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    • 제15권3호
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    • pp.219-225
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    • 2000
  • Bacillus thuringiensis를 생물농약으로 이용하기 위해서는 고농도의 포자형성에 의한 높은 살충성의 8 -endotoxin를 생산하는 것이 중요하다. 따라서 본 연구에서는 B. thuringiensis의 고농도 배양에 의한 높은 포자형성 수율을 얻기 위하여 40%의 용존산 소량과 $28^{\circ}C$에서 여랴 가지 방법의 유가식 배양법을 검토하였다. 최종 배양액의 glucose 농도가 50 g/L가 되도록 하는 경우의 유가식 배양에서는 continuos fed-batch culture의 linear gradient f feeding 법에 의하여 $9.37{\times}109$ cell/mL의 최대 생존 세포 수와 8 8.33 X 109 spore/mL의 최대 포자 수를 얻었으며, 이때의 포자 형 성율은 88.9% 이었다 최종 배양액의 glucose 농도가 100 m/L가 되도록 하는 경우의 유가식 배양에서는 intermittent fed-batch culture의 pH-stat 법에 의하여 $1.35{\times}1010$cell/mL의 최대 생존 세포 수와 $1.35{\times}1010$ spore/mL의 최대 포자 수를얻었으며, 이 때의 포자 형성율은 97.8% 이엇다.

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공압실린더를 활용한 롤 피더의 간헐적 스트립 스톡 진행 정밀도 분석 (Intermittent Strip Stock Advancing Accuracy Analysis of a Prototype Pneumatic Cylinder Driven Roll Feeder)

  • 서정덕;권순홍
    • 한국생산제조학회지
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    • 제19권3호
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    • pp.353-358
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    • 2010
  • This research introduces a new and improved design for a pneumatic cylinder driven roll feeder wherein each of the principal rotating feeder parts is configured so as to have feeding accuracy and to be low manufacturing cost. The feed pitch accuracy of the proposed roll feeder was evaluated by measuring lengths of cut offs of the strip stock with a shear attached to an air press. The air press was designed, manufactured, and mounted on the same table of the proposed roll feeder such that the strip stock maintained horizontal plane until the strip stock entered into the shear. The proposed roll feeder and the air press were designed to be operated automatically by a PLC employed controller. The feed pitch accuracy of the proposed roll feeder was analyzed by setting the pitch as 10, 12.5, and 15mm. At each predetermined feed pitch, the proposed roll feeder was tested 300 times as one test set and replicated three times. The average lengths of the cut offs of the strip stock ranged from 9.98 to 10.13mm, from 12.42 to 12.57mm, and from 14.96 to 15.06mm at the predetermined 10, 12.5, and 15mm feed pitch, respectively, among the total of 900 samples of each feed pitch. Main cause of variation of the length of the cut off of the strip stock fed by the proposed roll feeder was considered to be fluctuation of the air press during recompressing period of the air compressor to pressurize the air in the air tank. The largest difference between the maximum and the minimum length of the cut off was appeared while the air compressor recompressing the air. The air compressor used for this study restricted the air delivered to the proposed roll feeder while it was still running. Thus, this air delivery restriction problem should be improved by stabilizing the air press while the proposed roll feeder is running.

수평 흐름 제올라이트 갈대 여과상에 의한 생활하수 처리 (Horizontal Flow Zeolite-Filled Reed Bed with Intermittent Feeding for Sewage Treatment)

  • 서정윤;김은호
    • KSBB Journal
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    • 제21권1호
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    • pp.28-33
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    • 2006
  • 제올라이트로 충진된 수평 흐름 갈대 여과상에 실제하수를 간헐적으로 주입하면서 처리효율을 조사하였다. 여과상 표면적 $m^2$당 1일 314 L의 하수가 6시간마다 10분 동안 간헐적으로 주입되었다. 처리수의 pH는 원수보다 감소하였으며, 용존산소 농도는 원수보다 증가하였다. 수평 흐름 여과상에서 각 항목별 연중 평균 처리효율은 SS $88.5%,\;COD_{cr},\;86.1%,\;COD_{Mn}\;81.0%,\;T-N\;48.6%,\;NH_4^+-N\;97.1%$, T-P 42.8%이었다. 수평 흐름 여과상에서 처리수 중 T-N의 대부분은 $NO_3^--N$이었으며 $NO_2^--N$의 농도는 0.10 mg/L 이하이었다. 처리효율의 계절적 차이는 없었다.

급성 허혈성 뇌졸중에 수반된 연하장애에 관한 임상적 고찰 (Clinical Review about Dysphagia associated with Acute Ischemic Stroke)

  • 한명아;김동웅
    • 대한한의학회지
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    • 제22권3호
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    • pp.42-50
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    • 2001
  • Objectives : Dysphagia is common and severe problems of acute stroke determining the prognosis of stroke only second to mental change, and results in secondary fatal complications such as aspiration pneumonia, malnutrition, dehydration, etc. Therefore, we were to investigate the clinical characteristics of dysphagia accompanied by acute ischemic stroke. Methods : We selected subjects through clinical notes retrospectively, whose main problems included dysphagia resulted from acute stroke within 72 hours from onset who were admitted to the Internal Medicine Department of Wonkwang Oriental Medicine Hospital from Jan. 2000 to Apr. 2001. We assessed the severity of dysphagia from admission to discharge using a staging method : stage 0 is normal without dysphagia, stage 1 is nearly normal except for intermittent dysphagia, stage 2 is compensated abnormal swallowing requiring adjusted diets or delayed feeding time, stage 3 is uncompensated abnormal swallowing resulted in weight loss down to 10% of initial and daily aspiration, coughing, and vomiting, stage 4 is uncompensated abnormal swallowing resulting in weight loss beyond 10% and recommended for non-oral feeding, and stage 5 is 100% non-oral feeding by L-tube, or gastrostomy or NPO state. Results : Dysphagia was improved statistically significantly from the mean stage of $3.6{\pm}0.29$ on admission to $1.88{\pm}0.32$ on discharge (P<0.05). On average $7.1{\pm}1.48$ days were required for improving more than one stage level. As patients were older and the stage of dysphagia was worse on admission, severity of dysphagia was more difficult to improve (correlation coefficiency was 0.55 and 0.77 respectively, P<0.05). Aspiration pneumonia was complicated in 13 patients of the total 25 at mean dysphagia stage of $3.36{\pm}0.37$. However, any specific values such as lesion size, lesion site, sex, age, past history and NIH Stroke Scale on admission did not affect it (P>0.05). Conclusion : Clinical course of dysphagia was determined about I week from the onset. Aspiration pneumonia was mainly complicated during oral feeding periods. If there were no improvement of dysphagia over 2-3 weeks, then non-oral feeding such as Levin tube or gastrostomy must be considered.

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Characteristics of Macroinvertebrates Food Webs affected by Dry Channel in an Intermittent Stream System of the Echi River in Japan

  • Shin, Hyun-Seon;Nozomi, Amahashi;Na, Young-Eun;Park, Hong-Hyun;Cho, Kwang-Jin;Seo, Ye-Ji;Osamu, Mitamura
    • 한국기후변화학회지
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    • 제6권3호
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    • pp.167-173
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    • 2015
  • The purpose of study is to identify trophic pathways from organic matter to macroinvertebrates in terms of the consumer and to characterize the food webs in an intermittent stream system of the Echi River in Japan. The ${\delta}^{13}C$ values of macroinvertebrates and their potential food sources indicated the scraper (Psephenoides spp., Ecdyonurus levis) and collector-gatherer (Ephemera strigata, Paraleptonphlebia chocolata) feed on periphyton and POM (particulate organic matter) in situ. Davidius lunatus, and Hexatoma spp., which were identified as predators, may feed upon Ephemera strigata and Stenelmis larvae, respectively. At station characterized by seepage water, the ${\delta}^{15}N$ values of Ecdyonurus levis, Lymnaea auricularia, and Rhyacophila nigrocephala larva probably showed relatively lower values according to its diets. Even in homogenous species, the trophic pathways of macroinvertebrates in situ exhibited considerable variation; this reflected the trophic pathways from organic matter to the consumer depending on habitat characteristics in stream.

Pseudomonas sp. HJ로부터 Polyhydroxyalkanoate 대량생산을 위한 유가식 배양 (Fed-Batch Culture for Polyhydroxyalkanoate Overproduction by Pseudomonas sp. HJ)

  • 손홍주;이상준
    • KSBB Journal
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    • 제11권2호
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    • pp.201-210
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    • 1996
  • 본 연구는 단일 탄소원인 포도당으로부터 PHA를 생산하는 공시균 Pseudomonas sp. HJ의 유가배양 을 검토함으로써, PHA 대량생산을 위한 기초자료 를 얻는데 그 목적을 두었으며 그 결과는 다음과 같다. U 발효조를 이용하여 배양시 교반속도 4 400rpm, 통기량 2vvm, 종균 배양시간 18 시간 및 종균 접종량 5%(v/v)일때 최적 생육을 나타내었다. 공시균 Pseudomonas sp. HJ는 용존산소의 결핍 에 의해서 PHA 축적율이 향상되지 않았으며, P PHA 생산단계에 충분한 수준으로 용존산소를 유지 시켜 주어야 함을 알 수 있었다. 공시균 Pseudomo­7 nas sp. HJ를 회분배양했을 때 24시간만에 $6.251g/\ell$의 건조균체량과 20% 의 PHA 축적율을 나타내었으며, constant feeding fed-batch culture로 배 양 45시간만에 최고$33.24g/\ell$의 건조균체량과 48.9%의 PHA 축적율을 나타내었다. 또한 intermit­t tent feeding fed-batch culture로 공시균 Pseu domonas sp. HJ를 배양했을때, 배양 45시간만에 $37.89g/\ell$의 건조균체량과 53.5%의 PHA 축적율을 나타내였다.

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