• 제목/요약/키워드: Water Body

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압축공기로 움직이는 관 내부 수중 이동물체의 거동에 미치는 물의 압축성 영향 (The Effect of Water Compressibility on a Rigid Body Movement in a Water-filled Duct Driven by Compressed Air)

  • 박찬욱;이승수
    • 대한조선학회논문집
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    • 제45권4호
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    • pp.345-352
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    • 2008
  • The motion of a projectile initiated by the release of highly pressurized air is simulated presuming the flow field as a two dimensional one. The effects of water compressibility on projectile movements are investigated, comparing results based on the Fluent VOF model where water is treated as an incompressible medium with those from the presently developed VOF scheme. The present model considers compressibility of both air and water. The Fluent results show that the body moves farther and at higher speeds than the present ones. As time proceeds, the relative difference of speed and displacement between the two results drops substantially, after acoustic waves in water traverse and return the full length of the tube several times. To estimate instantaneous accelerations, however, requires implementation of the water compressibility effect as discrepancies between them do not decrease even after several pressure wave cycles.

농촌오수 처리수의 농업용수로의 재이용 가능성에 관한 연구 (Feasibility Study on the Reuse of Treated Sewage Effluent for Agrcultural Water)

  • 권태영;윤춘경
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.663-669
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    • 1999
  • The objective of this study are to examine the feasbility of reuse treated sewage effluent ofr agricultural water, and to obtain basic data for estabilishment of rational agricultural water quality standard. From this study, it appears that reuse of treated sewage as a supplemental irrigation water could be feasible and practical alternative for ultimate sewage disposal which often causes water quality problem to the receiving water body. For full scale applicatiion, further study is recommended on the secific guidelines of major water quality components and publc health.

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한국해양환경을 고려한 부유식 마리나 구조물의 운동성능 향상에 관한 연구 (A Study on the Improvement of the Motion Performance of Floating Marina Structures Considering Korea Coastal Environment)

  • 김동민;허상환;구원철
    • 한국해양공학회지
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    • 제33권1호
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    • pp.10-16
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    • 2019
  • The aim of this study was to improve the vertical motion performance of floating marina structures and to optimize the shapes of the structures for the Korea coastal environment. The floating body is connected to a plate-shaped submerged body through a connecting line under the water that has a stiff spring that serves to reduce the heave response. This system, which has two degrees of freedom, was modelled to analyze the interaction between the floating body and the submerged body. The vertical motion of the two-body system was compared with the motion of a single body to verify that the system could perform as an optimized model.

$\ll$황제내경(黄帝内经)$\gg$ "진액(津液)" 개념고변(概念考辨) (Analysis of the concept of body fluid in "Hwangjenaegyeong(黃帝內經)")

  • 곡봉;김효철
    • 대한한의학원전학회지
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    • 제23권1호
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    • pp.11-13
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    • 2010
  • In this article, the concept of body fluid is explained in three aspects: the word meaning of body fluid, the origins of the definitions of the body fluid concept and the connotation and extension of body fluid. Investigating data about the time Hwangjenaegyeong(黃帝內經) was written, the author discovers that the meaning of "Aek(液)" is clear, but there are still questions about the meaning of "Jin(津)". The concept of body fluid derived from observation of life phenomenon and ancient philosophy on the "water". The concept of body fluid should be expressed as that body fluid is a general term for all normal liquids in the body. Within the meridians, as the composition of blood components; outside the meridians, constituting the intrinsic body fluids of various organs and tissues. This is the main part of body fluid, coming from diet, constituting the human body and maintaining human life activities, playing the roles of moistening and nourishing various of organs and tissues of the body. In addition, Interstitial fluid, all kinds of normal liquid secretion and metabolic products, such as sweat, tears, nasal discharge, saliva, slobber, gastric juice, intestinal fluid, urine, joint fluid, latex and so on, both belong to body fluid.

갑상선암의 방사성옥소 치료 후 전신 스캔에서 비타민C 용액을 이용한 식도의 위양성 병소 제거에 대한 고찰 (An Elimination of False-Positive I-131 Sites in Esophagus for Thyroid Carcinoma; Using Water with Vitamin C Dissolved)

  • 이승재;박훈희;안샤론;조석원;최영숙;조응혁;김재삼;이창호
    • 핵의학기술
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    • 제12권1호
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    • pp.49-56
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    • 2008
  • Purpose: Whole body imaging with radioiodine can detect functioning metastases. Non-physiologic I-131 uptake detected on images usually is interpreted as suggesting functioning thyroid metastases. However, extra-thyroidal I-131 accumulation does not always imply thyroid cancer metastases and has been reported in many circumstances. In order to avoid unnecessary therapeutic interventions it is important to distinguish false-positive sites of I-131 localization. We study here to remove false-positive sites around esophagus region on I-131 whole body imaging in patients who were administrated thyroidectomy. Materials and Methods: From April to August in 2007, we had the patients who had visited our department after they received thyroidectomy due to thyroid cancer. They were given I-131, and performed radioiodine body scan after 41 to 50 hours. Patients were whole-body-scanned for the speed of 8 cm per minute. After that, we took anterior and posterior static images around the patients' neck measured by 300 thousand counts per image. We selected 44 patients who had hot spots around neck region, we divided the patients into two groups. One group was given 0.5 L of water and the other group was given 0.5 L of water with 1 g of Vitamin C dissolved. The patients were asked to drink the fluid for one minute in sitting position and after that, we measured 300 kilo counts per image again. We compared prior anterior, posterior static images with anterior, posterior images after the patients had water or water that Vitamin C resolved. Results: In using water, both observer 1 and 2 interpreted 6 patients were washed out. In the water with Vitamin C resolved, observer 1 and 2 interpreted 9 and 8 patients were washed out. Observer 1 and 2 interpreted 6 and 5 patients had 'indeterminate' when they used water. Both observer 1 and 2 interpreted 6 patients had 'indeterminate' when they used water with Vitamin C resolved. When they used water, observer 1 interpreted 10 patients had 'unchanged' and observer 2 interpreted 11 patients had 'unchanged'. Differently, when they used water with vitamin C resolved, observer1 had 8 patients having 'unchanged'and observer 2 had 9. Conclusion: As a result, by making patients drink 0.5 liter of water which has vitamin C resolved helped getting rid of false-positive sites in esophagus. Therefore, based on this study, we believe that drinking water with vitamin C dissolved is very in terms of reducing false-positive hot spot around the esophagus for the iodine-131 whole body scan.

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동부태평양 한국의 다랑어 연승어업에서 상어류 체중대비 지느러미 중량 비율 추정 (Estimation of the Ratio of Fin Weight to Body Weight of Sharks for the Korean Tuna Longline Fishery in the Eastern Pacific Ocean)

  • 안두해;권유정;문대연;황선재;김순송
    • 한국수산과학회지
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    • 제42권2호
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    • pp.157-164
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    • 2009
  • The National Fisheries Research and Development Institute (NFRDI) conducted a circle hook experiment to compare the catch rates of target and bycatch species between J hook and circle hooks in the tuna longline fishery of the Eastern Pacific Ocean, which is located between $9^{\circ}13'S-1^{\circ}36'N$ and $126^{\circ}00'-138^{\circ}21'W$. Sampling was conducted from September 20 to October 23, in 2006. In this survey, we collected shark data to obtain the ratio of fin weight to body weight of sharks. Overall, 413 sharks belonging to 9 species were caught on 62,464 hooks. The total weight of the sharks caught was 11,093 kg. The ratio of wet fin weight to body round weight of sharks by species ranged from 3.7% to 7.7%, while the mean was 5.4%. The total ratio of wet fin weight to the dry fin weight of sharks ranged 0.38 to 0.70 and the mean value was 0.53. The ratio of dry fin weight to the body round weight of the sharks was estimated to be 2.86%.

Effect of Nursing Frequency and Creep Feed Provision on the Milk and Feed Intake and Performance of Zero Day Weaned Piglets Reared on a Dummy Sow

  • Weng, R.C.;Edwards, S.A.;Hsia, L.C.
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권11호
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    • pp.1540-1546
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    • 2009
  • One hundred and forty-four piglets with an average birth weight of 1,672${\pm}$13.4 g were used to evaluate different feeding strategies for piglets reared from birth on a dummy sow. A 3${\times}$2 factorial experiment compared three nursing frequencies (1, 3 or 6 h intervals) and two feeding regimes (milk only, or milk combined with access to creep feed and water). The piglets which were nursed at one hour intervals had the lightest body weights at all days, and the poorest combined milk and creep feed dry matter conversion efficiency to piglet body weight gain in the second week. Piglets which were nursed at 3 h intervals had the heaviest body weight at day 15 and 22, but those nursed at 6 h intervals achieved similar body weight by days 29 (milk withdrawal) and 36. Piglets offered creep feed were observed to wean themselves before cessation of milk availability, and the timing of this self-weaning depended on the nursing frequency. The piglets nursed at one hour intervals weaned themselves between day 22 and day 29, those nursed at 3 h intervals weaned themselves between day 15 and day 22, whilst those nursed at 6 h intervals weaned themselves between day 8 and day 15. The piglets which were nursed at 6 h intervals had the highest total dry matter intake in weeks 3 and 4 when fed with milk, creep feed and water but not when fed milk only. They consequently had the poorest dry matter conversion efficiency in the fourth week and overall when fed with milk, creep feed and water, but not when fed milk only. It is concluded that the optimal management routine under these conditions is a 3 h nursing cycle with provision of supplementary creep feed and water.

저수온, 적수온, 고수온에서 미성어기 조피볼락(Sebastes schlegeli)의 배합사료 적정 공급률 (Optimal Feeding Rates of Subadult Korean Rockfish Sebastes schlegeli Fed a Commercial Diet at Different Water Temperatures)

  • 김민기;이초롱;김유정;오대한;이봉주;김성삼;이경준
    • 한국수산과학회지
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    • 제48권3호
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    • pp.322-328
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    • 2015
  • Three feeding trials were conducted to investigate the optimal feeding rates of subadult Korean rockfish Sebastes schlegeli at low, optimal and high water temperatures. In Exp-I, triplicate groups of fish (248 g) were fed a commercial diet (CD) with five different feeding rates of 0.1%, 0.2%, 0.4%, 0.6% and 0.8% body weight per day for 10 weeks at the low temperature ($11.6-15.2^{\circ}C$). In Exp-II, fish (129 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 10 weeks at the optimal temperature ($16.0-18.8^{\circ}C$). In Exp-III, fish (85.7 g) were fed the same CD with five different feeding rates of 0.4%, 0.8%, 1.2%, 1.6% and 2.0% body weight per day for 12 weeks at the high temperature ($21.0-28.5^{\circ}C$). The optimal feeding rates in the low, optimal, and high water temperatures were estimated to be 0.56%, 0.93% and 1.17% body weight per day, respectively, for subadult Korean rockfish.