• Title/Summary/Keyword: Back-flow

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Nitrogen Removal Rate of A Subsurface Flow Treatment Wetland System Constructed on Floodplain During Its Initial Operating Stage (하천고수부지 수질정화 여과습지의 초기운영단계 질소제거)

  • Yang, Hong-Mo
    • Korean Journal of Environmental Agriculture
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    • v.22 no.4
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    • pp.278-283
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    • 2003
  • This study was carried out to examine the nitrogen removal rate of a subsurface-flow treatment wetland system which was constructed on floodplain of the Kwangju River from May to June 2001. Its dimensions were 29m in length, 9m in width and 0.65m in depth. A bottom layer of 45cm in depth was filled with crushed granite with about $15{\sim}30\;mm$ in diameter and a middle layer of 10cm in depth had pea pebbles with about 10 mm in diameter. An upper layer of 5 cm in depth contained course sand. Reeds (Phragmites australis) were transplanted on the surface of the system. They were dug out of natural wetlands and stems were cut at about 40 cm height from their bottom ends. Water of the Kwangju River flowed into it via a pipe by gravity flow and its effluent was funneled back into the river. The height of reed stems was 44.2 cm in July 2001 and 75.3cm in September 2001. The number of stems was increased from $80\;stems/m^2$ in July 2001 to $136\;stems/m^2$ in September 2001. Volume and water quality of inflow and outflow were analyzed from July 2001 through December 2001. Inflow and outflow averaged 40.0 and $39.2\;m^3/day$, respectively. Hydraulic detention time was about 1.5 days. Average nitrogen uptake by reeds was $69.31\;N\;mg/m^2/day$. Removal rate of $NO_3-N$, $NH_3-N$, T-N averaged 195.58, 53.65, and $628.44\;mg/m^2/day$, respectively. Changes of $NO_3-N$ and $NH_3-N$ abatement rates were closely related to those of wetland temperatures. The lower removal rate of nitrogen species compared with that of subsurface-flow wetlands operating in North America could be attributed to the initial stage of the system and inclusion of two cold months into the six-month monitoring period. Increase of standing density of reeds within a few years will develop both root zones suitable for the nitrification of ammonia and surface layer substrates beneficial to the denitrification of nitrates into nitrogen gases, which may lead to increment in the nitrogen retention rate.

Selection and Treatment Effect of Plant Growth Retardants on Potted Spathiphyllum Grown in a Recirculating Subirrigation System (순환식 저면관수 시스템을 이용한 스파티필럼의 생장조절제 선발과 처리효과)

  • Won, Eun Jeong;Park, Yoo Gyeong;Jeong, Byoung Ryong
    • FLOWER RESEARCH JOURNAL
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    • v.19 no.2
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    • pp.81-88
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    • 2011
  • Effect of concentrations of different plant growth retardants (PGRs) supplied to a recirculated nutrient solution in an ebb and flow system on the growth and development of potted Spathiphyllum 'Top-Pin' and 'Mini' was examined. Plants were planted in 10 cm diameter plastic pots filled with a mixture of peat moss and perlite (1 : 1, v/v) on 30 June 2005 and grown until 23 Sep. 2005. In a closed ebb and flow system, 50, 200, 350, $500mg{\cdot}L^{-1}$ daminozide (B-9), 10, 40, 70, $100mg{\cdot}L^{-1}$ paclobutrazol (Boundy), 5, 15, 25, $35mg{\cdot}L^{-1}$ ethephon (Florel), and 1, 4, 7, $10mg{\cdot}L^{-1}$ uniconazole (Sumagic) were supplemented to a nutrient solution at the initiation of experiment. On every irrigation, the nutrient solution containing PGRs was supplied at a 2 cm depth and kept for 15-20 minutes. The surplus nutrient solution was drained back into the tank for next irrigations. Paclobutrazol gave the most pronounced effect in inhibition of stretchiness. The greatest reduction of leaf length, fresh and dry weights of shoot, and elevated chlorophyll content were recorded in Spathiphyllum, with increasing paclobutrazol concentration. Daminozide concentration greater than $200mg{\cdot}L^{-1}$ resulted in minor stunting. The lowest concentration ($1mg{\cdot}L^{-1}$) of uniconazole showed greater leaf length, leaf width, and leaf petiole length than the control ($0mg{\cdot}L^{-1}$). Uniconazole concentration greater than $1mg{\cdot}L^{-1}$ resulted in similar plant growth as the plant in the control ($0mg{\cdot}L^{-1}$). High concentration ($35mg{\cdot}L^{-1}$) of ethephon resulted in the shortest leaf length, and the greatest chlorophyll content. Inhibition of stretchiness was observed even in the lowest concentration treatments. Among the PGRs, paclobutrazol was most effective in suppressing plant stretchiness. In both cultivars, ethephon and paclobutrazol, but not daminozide and uniconazole, significantly inhibited stretchiness. The results suggested that plant growth retardants (ethephon or paclobutrazol) selected in this study may be used as the most effective agents for inhibition of stretchiness in Spathiphyllum.

Studies on the phrases of Yellow Emperor's internal classic(黃帝內經) for the physiology on the spleen and stomach (비위생리(脾胃生理)에 수용(授用)되는 황제내경(黃帝內經) 어구(語句)에 관(關)한 연구(硏究))

  • Won, Jin-Hui
    • The Journal of Korean Medicine
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    • v.16 no.2 s.30
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    • pp.453-489
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    • 1995
  • The research of the phrases related with physiology of stomach and spleen in the contents of Huang Di Nei Jing(黃帝內經) known as the Bible of oriental medicine will make a contribution to a deep understanding of disease of stomach and spleen and a proper clinical diagnosis and treatment of them. In this research of the most appropriate glosses recorded nine kinds of representative medical books including Huang Di Nei Jing Somoon(黃帝內經素問) of Wang Bing(王氷) were picked out: The summaries of the selected contents are as follows: 1. The word 'saliva(涎)' in 'the spleen controls saliva(脾爲涎)' can be viewed as a generic term referring to oral cavity secretion gland as well as the secretion fluid of salivary gland. 2. The phases 'a large reservoir(太倉)', barn organs', 'a reserboir of food stuff', 'a stomach as the market(胃爲之市)', etc mean the function of stomach to receive food(胃主受納). 3. The phase 'generation of five tastes(五味出焉)' means both 'the function of stomach to transform food into chyme(胃主腐熟)' and 'the channelling function of spleen.(脾主運化)' 4. The flowing of the food-Qi(食氣) into stomach brings about spreading Jung(精) into liver and then percolating Jung(精) flow into channel. The channel-Qi(脈氣) flows into lung through channel. As a result, all kinds of channels gather together in lung and Jung(精) is sent into skin and hair. The assembly of Jung(精) with skins and channels moves Qi(氣) into fu-organ and so jung(精) and mental activity(神明) in fu-organ(府) come to be in four organs(四臟). Then if Qi(氣) comes back to power balance unit(權衡) being in the state of equilibrium(權衡以平), the hole of Qi(氣口) comes to determine the matter of life and death through achieving Chun-quan-chi(-寸-關-尺). The above mentioned phrases means the digestion, asorption and transmission of food. When food is taken in stomach, Jung-Qi(精氣) comes to be over flowed upward into spleen, back into lung, finally downward into bladders through water-conduit(水道) controlled by lung. When water- Jung(水精) radiates into whole body with channels of five organs(五臟), both of them fit together with and yin-yang(陰-陽). Therefore, the grasping of the rise and decline of yin-yang(陰C-陽) is necessary to consult patients. The above mentioned phrases is properly viewed to designate the asorption, transmission and excretion of food. 5. Spleen controls flesh(脾之合肉也), the state of spleen is known by human lips, and what this means is that liver plays functions of spread and expansion(肝主疏泄). 6. The phrase 'Jung Jung'((中精)) in 'gallbladder dominates Jung jung(膽主中精)', which in one of the specific expression of 'liver plays functions of spread and expansion(肝主疏泄). 7. It is right that the phase 'The eleven organs in all are determined by gallbladder'(凡十,一臟取決於膽也) is correctly paraphrased as 'only one of ten organs, spleen, is determined by gallbladder'.(凡十,一臟取決於膽也), 8. The small intestine is an organ. which receives the materials digested and sends them out. This means that the function of transforming materials(化物) factually refers to that of separating clearity and blur(泌別淸濁). And it is also thought to have the function of ascending clearity and descending blur(升淸降濁), 9. A large intestine is a transmitting organ(傳導之官) from which a change comes out(變化出焉). the phrase 'change'(變化) in this sentence means both the intake of water and nutrition and the formation procedure of stool through excretion of mucocele.

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A Study on the Establishment of Optimal Transportation Networks in Busan New Port (부산항 신항 최적의 교통망 수립에 관한 연구)

  • Park, Ho-Kyo;Choi, Yang-Won
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.1
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    • pp.125-132
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    • 2017
  • The development project of Busan New Port aims to be Logistics Hub Port but there are too many things to deal with ; enlargement of harbour, interport competition, modernization of harbour loading equipment and so on. At present, 23 berths of North and South container quay are in operation and 22 berths will be constructed on west and south-side by 2020. Namely, Busan New Port will operate 45 berths in 2020. When it comes to port distripark, a large-scale of Port distripark project is underway, such as Ung-Dong district 1,2 phase, West container 1,2phase, North distripark and so on. This study is to deduce traffic system problem of Busan New Port which is caused by the development project through predicting traffic need considering the development project. According to study, there are three main problems of traffic system : 1. traffic congestion caused on main crossroad, connecting second harbour back road. 2. It has been predicted that South-North road and traffic capacity of New Port road would lack compared to traffic volume-to-be-increased. Moreover, the detour volume of traffic is caused because New Port's 1st avenue and route 2 were not connected directly. Thus, this study suggests three kinds of improvement plan for smoother traffic flow. 1st. Operate roundabout on major intersection, for example, second harbour back road, west container wharf's subway corridors(South to North), and permit only right turn on sub-intersection. 2nd. Extend New Port road(North container's port road) by utilizing side walk and median. 3rd. Install exit ramp which utilizes Route 2 connecting New Port's 1st avenue and local road 1042. The method we used to analyze the effect of improvement is Vissim of Mircro Simulation Package.

A Study Concerning the Background of Formation in Deleuze's System (들뢰즈 체계의 형성 배경에 대한 연구 - 칸트 선험철학 체계 그 심연으로부터의 역류 -)

  • Kim, Dae-hyeon
    • Journal of the Daesoon Academy of Sciences
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    • v.37
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    • pp.329-355
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    • 2021
  • The objective of this paper is to reveal that the formation of Deleuze's system is a result of a back flow of the 'ideal of pure reason' in Kant's system. I will try to seize upon the keyword in his main book, Difference and Repetition, and examine the aspect of mutual transformation between Deleuze's transcendental empiricism and Kant's transcendentalism. When analyzing Deleuze's system, most researchers tend to focus on anti-Hegelianism, but it is proper that Kant be adopted as the start when tracing the way of deployment directly. Fundamentally, Deleuze is different from Hegel in his approach to observing entire ground of thought. Even if Deleuze surely has the capability of becoming in the dialectical context, his systemic environment wherein dialectics is applied is different even at the onset. While Hegel follows the way of origin and copy or a system that begins from a preceding point of origin, Deleuze follows a way of copy and recopy or a system that begins without a point of origin. This characteristic of Deleuze's system originates directly from idealistic play. In fact, we can anticipate and identify in his book that he refers to Kant who accepted the tradition of empiricism. Therefore, the main contents of this paper is to present an overview of Kant's influence on Deleuze's system. While tracing ideas back to Kant's system, the cohabitation of empiricism and rationalism, which Kant felicitously revoiced, there emerges a definitude of world recognition. This occurs through cohabitation, and this is both deconstructed and integrated by Deleuze, and therein definitude is turned into a vision of prosperity. To the vision of prosperity that spans definitude to recognition, a philosopher has the right to select a philosophical system because selection methodology in philosophy is not a problem of legitimacy so much as the needs of the times. Deleuze's choice resulted in the opening of pandora's box in an abyss and secret contents have in turn risen sharply.

Effects of Cecal Ligation and Colostomy on Food and Water Intake and loafer Excretion in Chickens Fed Restrictedly and Freely (닭에 있어서 사료섭취의 자유 및 제한급여시킬 때의 사료섭취량, 음수량 및 수분 배설량에 미치는 맹장결찰 및 인공항문 수술의 효과)

  • Son, J.H.
    • Korean Journal of Poultry Science
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    • v.29 no.4
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    • pp.259-263
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    • 2002
  • It was examined whether the ceca and the back-flow of urine into the lower intestine are involved in water intake and excretion in chickens and food intake affects those. Colostomy significantly increased water intake, total water excretion and the ratio of the water intake to food intake in the ceca-ligated chickens under restrict and ad libitum feeding conditions (P<0.05), but the increases were much larger in chickens fed ad libitum than in those fed restrictedly. Cecal ligation increased water intake, total water excretion and the ratio of water intake to food intake in the colostomised chickens which were fed freely (P<0.05). but not in those fed restrictedly, None of colostomy and cecal ligation affected the resultant water balances in chickens under both feeding conditions. Colostomy increased food intake in the ceca-ligated chickens (P<0.05), but no increase by cecal ligation was observed in colostomised chickens. It is concluded that the lower intestine takes a very important role in water recovery from urine to maintain water balance in chickens.

Correlation between Epidurographic Contrast Flow Patterns and Clinical Effectiveness in Chronic Lumbar Discogenic Radicular Pain Treated with Epidural Steroid Injections Via Different Approaches

  • Gupta, Ruchi;Singh, Saru;Kaur, Sukhdeep;Singh, Kulvinder;Aujla, Kuljeet
    • The Korean Journal of Pain
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    • v.27 no.4
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    • pp.353-359
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    • 2014
  • Background: Epidural steroid injections are an accepted procedure for the conservative management of chronic backache caused by lumbar disc pathology. The purpose of this study was to evaluate the epidurographic findings for the midline, transforaminal and parasagittal approaches in lumbar epidural steroid injections, and correlating them with the clinical improvement. Methods: Sixty chronic lower back pain patients with unilateral radiculitis from a herniated/degenerated disc were enrolled. After screening the patients according to the exclusion criteria and randomly allocating them to 3 groups of 20 patients, fluoroscopic contrast enhanced epidural steroids were injected via midline (group 1), transforaminal (group 2) and parasagittal interlaminar (group 3) approaches at the level of the pathology. The fluoroscopic patterns of the three groups were studied and correlated with the clinical improvement measured by the VAS over the next 3 months; any incidences of complications were recorded. Results: The transforaminal group presented better results in terms of VAS reduction than the midline and parasagittal approach groups (P < 0.05). The epidurography showed a better ventral spread for both the transforaminal (P < 0.001) and the paramedian approaches (P < 0.05), as compared to the midline approach. The nerve root filling was greater in the transforaminal group (P < 0.001) than in the other two groups. The ventral spread of the contrast agent was associated with improvement in the VAS score and this difference was statistically significant in group 1 (P < 0.05), and highly significant in groups 2 and 3 (P < 0.001). In all the groups, any complications observed were transient and minor. Conclusions: The midline and paramedian approaches are technically easier and statistically comparable, but clinically less efficacious than the transforaminal approach. The incidence of ventral spread and nerve root delineation show a definite correlation with clinical improvement. However, an longer follow-up period is advisable for a better evaluation of the actual outcom.

Status of Sediment Dynamics in Lake Takkobu of the Kushiro Mire, Japan, Associated with Forestry and Agricultural Development in the Watershed (산림과 농업 개발로 인한 쿠시로습원 타호부호수의 최근 토사동태)

  • Ahn, Young-Sang
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.5
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    • pp.755-763
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    • 2010
  • Fine sediment loadings from agricultural watersheds have led to habitat degradation in Lake Takkobu, northern Japan. Fifteen lake sediment core samples were obtained and analyzed to develop a chronology using physical sediment characters, $^{137}Cs$, and tephra. The reconstructed sedimentation rates over the past ca 300 years suggested that sedimentation rates increased drastically after land use development. With a natural sedimentation rate of 0.1-1.1 mm $year^{-1}$ until 1898, lake sedimentation accelerated to 0.6-12.8 mm $year^{-1}$ after 1898. The sedimentation rates after land use change, such as forestry, river engineering works, and agricultural development, were about 6-12 times higher than that under natural conditions, leading to accelerated lake shallowing over the last ca 100 years. Sedimentation rates between 1898 and 1963 differed with location in the lake because of spatial variation in the sediment flux from the contributing rivers and their watersheds. The sedimentation rate in the southern zone between 1898 and 1963 was significantly higher than that in the middle and northern zones, reflecting active sediment production associated with forestry for charcoal production and canal construction for transportation in the southern watersheds and wetlands. The sedimentation rate after 1963 did not vary among the three zones, because decreasing sedimentation was found in most of the southern sites whereas an increasing trend was observed in the middle and northern sites. This result can be explained by shallowing of lake-bottom morphology with sedimentation and the resultant reduction of sediment retention capacity in the southern zone. Moreover, the sedimentation rate at sampling sites close to river mouths increased by 5-32 times compared with natural rates before 1898. The Kushiro River, into which Lake Takkobu drains under regular flow conditions, further contributed to an increased sedimentation rate, because water from the Kushiro River flows back into Lake Takkobu during floods.

A Numerical Study on the Basic Design of Scrubber for Marine Diesel Engines (선박 디젤기관 스크러버의 기초설계에 관한 수치적 연구)

  • Lee, Won-Ju;Kim, In-Su;Choi, Yong-Seok;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.5
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    • pp.549-557
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    • 2017
  • Numerical studies have been carried out on scrubbers, which are after-treatment devices to satisfy strengthened emission regulations for sulfur dioxide and particulate matter. We investigated the problems with existing scrubbers through numerical analysis and designed and analyzed a new swirl-type scrubber that could solve these problems. As a result, with the swirl-type scrubber, exhaust gas formed a vortex in the lower part of the device, and some of this gas was released along the guide vane through the bottom surface. In this case, the pressure gradient in the vertical direction was not large, but a pressure difference between the inside and outside of the baffle was generated. The shape of the exhaust gas stream was investigated, and when water was not sprayed, the exhaust gas flowed constantly to the outlet along the guide vane, in contrast to when water was sprayed. It was confirmed that the shape of the flow was influenced by the guide vane, nozzle arrangement and water pressure. In the case of the swirl-type scrubber, impact on engine back-pressure was minimal, because differential pressure at the inlet and outlet was less than half of that with a conventional scrubber.

Geotechnical investigation on causes and mitigation of ground subsidence during underground structure construction (터널 및 지중매설물 시공에 따른 지반함몰 발생 원인 및 대책에 대한 지반공학적 조사 연구)

  • Choi, Shin-Kyu;Back, Seung-Hun;An, Jun-Beom;Kwon, Tae-Hyuk
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.2
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    • pp.143-154
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    • 2016
  • This study investigated the occurrences, causes, and mitigation of the recent ground subsidence and underground cavity generation events in Korea. Two main causes of ground subsidence are (1) the soil erosion by seepage during tunneling and earth excavation and (2) the damage of underground pipes. The main cause of the soil erosion during tunneling was the uncontrolled groundwater flow. Especially, when excavating soft grounds using a tunnel boring machine (TBM), the ground near TBM operation halt points were found to be the most vulnerable to failure. The damage of underground pipes was mainly caused by poor construction, material deterioration, and differential settlement in soft soils. The ground subsidence during tunneling and earth excavation can be managed by monitoring the outflow of groundwater and eroded soils in construction sites. It is expected that the ground subsidence by the underground pipe damage can be managed or mitigated by life cycle analysis and maintenance of the buried pipes, and by controlling the earth pressure distribution or increasing the bearing capacity at the upper ground of the buried pipes.