• Title/Summary/Keyword: water level control

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Dynamic Response Analysis of Pneumatic Floating Breakwater Mounted Wave-power Generation System of Oscillating Water Column (진동수주형 파력발전시스템을 탑재한 공기주입식 부유식방파제의 동적거동해석)

  • Lee, Kwang-Ho;Kim, Do-Sam;Jung, Ik-Han
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.6
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    • pp.305-314
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    • 2017
  • Ocean wave energy harvesting is still too expensive despite developing a variety of wave energy converter (WEC) devices. For the cost-effective wave energy harvesting, it can be an effective measure to use existing breakwaters or newly installed breakwaters for both wave control and energy harvesting purposes. In this study, we investigated the functionality of both breakwater and wave-power generator for the oscillating water column (OWC)-type wave energy converter (WEC) installed in a pneumatic floating breakwater, which was originally developed as a floating breakwater. In order to verify the performance of the breakwater as a WEC, the air flow velocity from air-chamber to WEC has to be evaluated properly. Therefore, air flow velocity, wave transformation and motion of floating structure was numerically implemented based on BEM from linear velocity potential theory without considering the compressibility of air within the chamber. Air pressure, meanwhile, was assumed to be fluctuated by the motions of structure and the water level change within air-chamber. The validity of the obtained values can be determined by comparing the previous results from the numerical analysis for different shapes. Based on numerical model results, wave transformation characteristics around OWC system mounted on the fixed and floating breakwaters, and motions of the structure with air flow velocities are investigated. In summary, all numerical results are almost identical to the previous research considering air compressibility. Therefore, it can be concluded that this analysis not considering air compressibility in the air chamber is more efficient and practical method.

The Effects of Condensed Molasses Solubles(CMS) / Molasses Mixtures on Ruminal Microbial Protein Synthesis (Condensed Molasses Solubles(CMS) / 당밀 혼합물이 반추위 미생물 단백질 합성량에 미치는 영향)

  • Yeo, J.M.;Jeong, S.G.;Kim, H.S.;Ahn, B.S.;Kim, C.H.;Shin, H.T.
    • Journal of Animal Science and Technology
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    • v.46 no.1
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    • pp.61-68
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    • 2004
  • An experiment was conducted to evaluate condensed molasses solubles(CMS, a by-product from monosodium glutamate production) as a source of nitrogen for ruminant with particular reference to its effects on microbial protein synthesis. Four non-lactating dairy cows fitted with rumen cannulas were used in a 4 ${\times}$ 4 Latin square with 14-day periods. The four treatments were (1) basal diet consisting of barley straw ad libitum and 3 kg/d of rolled barley, (2) basal diet plus 200 gld molasses and 300 g/d water, (3) basal diet plus 200 g/d molasses, 100 g/d CMS and 200 g/d water, (4) basal diet plus 200 g/d molasses, 200 g/d CMS and 100 g/d water. Ruminal pH remained at high levels and showed little variation during the day between treatments. The concentration of total and individual VFA in the rumen was similar between treatments. There was no difference in the concentration of ammonia in the rumen between treatments, although the intake of nitrogen in molassesl CMS mixture treatments was higher than that of control and molasses treatment. But there was a suggestion of an increased synthesis of microbial protein with the higher level of inclusion of CMS when the allantoin/creatinine ratio was used as an index of microbial protein production(P <0.10).

Semiweekly Variation of Spring Population of a Mixotrophic Ciliate Myrionecta rubra (=Mesodinium rubrum) in Keum River Estuary, Korea (춘계 금강 하구에서 혼합영양 섬모류인 Myrionecta rubra (=Mesodinium rubrum) 개체군의 단주기 변동)

  • Yih, Won-Ho;Myung, Geum-Og;Kim, Hyung-Seop;Jeong, Hae-Jin
    • ALGAE
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    • v.20 no.3
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    • pp.207-216
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    • 2005
  • Myrionecta rubra, a mixotrophic ciliate, is a cosmopolitan red tide species which is commonly found in neritic and estuarine waters. M. rubra had long been listed as an “nculturable protist”until 2 different laboratory strains were finally established in 2 research groups at the beginning of this century, enabling us to perform initiative investigation into various aspect of the live M. rubra strains (Gustafson et al. 2000; Yih et al. 2004b; Johnson and Stoecker 2005). Field sampling was carried out on high tide at 2 fixed stations around Kunsan Inner Harbor (St.1 near the Estuarine Weir and St.2 off Kunsan Ferry Station) every other day for 4 months from mid-February 2004 to understand detailed figure of the recurrent spring blooms of M. rubra following the onset of the water gates operation of the Keum River Estuarine Weir on August 1994. With its maximum abundance of 272 cells mL$^{-1}$ in St.1, fluctuation pattern of the M. rubra population at the 2 stations was strikingly similar. Notable growth of M. rubra population started on late April, to cause M. rubra red tides during one month from mid-May in which “xceptionally low salinity days”without its red tide were intermittently inserted. High abundance of M. rubra over 50 cells mL$^{-1}$ was recorded at samples with their water temperature and salinity higher than 15${^{\circ}C}$ and 4.0 psu, respectively. During pre-bloom period when salinity fluctuation is moderate and the water temperature is cooler than 15°C, Skeletonema costatum, a chain-forming centric diatom, was most dominant. Cyanobacterial species such as Aphanizomenon flos-aquae and Phormidium sp. replaced other dominant phytoplankters on the days with “xceptionally low salinity”even during the main blooming period of M. rubra. To summarize, M. rubra could form spring blooms in Keum River Estuary when the level of salinity fluctuation was more severe than that for the dominant diatom Skeletonema costatum and milder than that for the predominance by freshwater cyanobacteria. Therefore, optimal control of the scale and frequency of freshwater discharges might lead us to partially modify the fluctuation pattern of M. rubra populations as well as the period of spring blooms by M. rubra in Keum River Estuary. Sampling time interval of 2 days for the present study or daily sampling was concluded to be minimally required for the detailed exploration into the spring blooms by M. rubra populations in estuaries with weirs like Keum River Estuary.

Effect of Fermented Small Soybean Powder Mixed with Mulberry Leaf on Metabolic Improvement and Hexokinase Activity in Streptozotocin-induced Diabetic Rats

  • Kim, Sun-Mi;Han, Jin-Chul;Park, Hum-Dai;Ko, Ki-Sung;Lee, Dae-Hoon;Kim, Sung-Min;Kwon, Dong-Yeul;Kim, Jin-Sook;Kim, Ok-Hee;Hwang, Jin-Bong;Gung, Bae-Nahm;Choo, Young-Kug
    • Nutritional Sciences
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    • v.9 no.2
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    • pp.97-105
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    • 2006
  • Beans are well known to be high-protein diets. Bean seeds contain arginine, lysine, or glycine-rich proteins which are effective to maintain lower glucose levels. In this study, the synergistic effect of fermented small soybean (Chounggukjang) and mulberry leaf on metabolism and hexokinase activity was investigated in streptozotocin (STZ)-induced diabetic rats. We divided 8 groups as follows: non-diabetic rat group fed with only water diet (NC: control), and STZ-induced diabetic rat groups fed with water (DC), fermented Rhynchosia Nulubilis (Bbc), fermented Glycine max Merr (Ybc), Bbc and YBc (BYbc), mulberry leaf and Bbc (MBbc), mulberry leaf and Ybc (MYbc), or the mulberry leaf, Bbc, and Ybc (MBYbc). Diabetes mellitus was induced in rats by subcutaneous STZ administration (70 mg/kg of body weight). All diet groups were fed with Chounggukjang in a powder form. Three ml of Chounggukjang solution (0.75 mg per gram of body weight) dissolved in distilled water was orally administered to all rat groups after STZ administration except for NC rat group. In groups fed with fermented soybeans, the body weight (increased), food efficiency ratio (FER) (increased), glucose level (decreased) and hexokinase (HK) activity (increased) significantly differed to NC. Among them, particularly in the groups fed with both fermented soybeans and mulberry leaf, kidney weight significantly decreased, whereas HK activity significantly increased compared to DC. These results suggest that Chounggukjang of both fermented soybeans and mulberry leaf is potentially used as an effective functional food to prevent diabetes complications.

Seasonal Variations of Primary Productivity Analyzed by Phyto-PAM Chlorophyll Fluorometry in the Beopsu Marsh, Haman-gun, Gyeongsangnam-do (경상남도 함안군, 법수늪에서 엽록소 형광광도계(Phyto-PAM)에 의한 일차생산의 계절변동)

  • Kim, Mi-Kyung
    • Korean Journal of Environmental Biology
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    • v.26 no.2
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    • pp.76-86
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    • 2008
  • The seasonal variations of primary production were investigated by phyto-PAM chlorophyll fluorometry as well as classical methods (standing crops of phytoplanktons and chlorophyll ${\alpha}$) in the Beopsu Marsh, Haman-gun, Gyeongsangnam-do. The amounts of turbidity, SS, T-N, T-P, BOD, COD, Ca$^{2+}$ and Cl$^-$ were the highest at the station 3, where located in flowout site of wastewater treated by the filtration plants. The water quality was the third level by the standard of BOD and COD. The amount of chlorophyll a (268.8 mg L$^{-1}$) was the highest at the station 2 in April because the cell density (2,677 cells mL$^{-1}$) of Micractinium pusillum increased suddenly from February (180 cells mL$^{-1}$). The patterns of primary production of phytoplankton by phyto-PAM chlorophyll fluorometry were fallen in with those of standing crops and chlorophyll a of phyto-planktons. The primary production was varied according to stations and seasons. The water environments of the Beopsu Marsh as a natural mounument should be under the control of a regular examination in order to preserve the ecosystem.

Effects of Artificial Acid Mist on Leaf Injury and Surface Wettability of Several Broad-Leaved Species (인공산성연무(人工酸性煙霧)의 처리(處理)가 몇 활엽수종(闊葉樹種)의 엽피해(葉被害)와 엽표면(葉表面)의 친수성(親水性)에 미치는 영향(影響))

  • Kim, Gab Tae;Um, Tae Won
    • Journal of Korean Society of Forest Science
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    • v.85 no.4
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    • pp.577-585
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    • 1996
  • To seek effective methods for evaluating air pollution and acid rain injury, artificial acid mist(pH 2.5, 3.5 and 4.5) and ground water(pH 6.5) were treated on the potted seedlings of Ligustrum obtusifolium, Cercis chinensis, Hibiscus syriacus and Sophora japonica. Leaf chlorophyll contents, characteristics of leaf-injury, wettability-measurement of diameter of water-droplets on the leaf surface-among treatments were investigated. The results were summarized as follows. 1. Chlorophyll contents of Ligustrum obtusifolium and Hibiscus syriacus measured on June 3 were highest in pH 2.5 plot, but those of Cercis chinensis and Sophora japonica were relatively low level. Chlorophyll contents of Ligustrum obtusifolium measured on August 24 was highest in pH 2.5 plot, but those of Cercis chinensis, Hibiscus syriacus and Sophora japonica were highest in the control. 2. Changes of chlorophyll contents with acid mist treatments were differed among tree species. 3. For all the tested species, leaf injury(injured leaf number and rate, and injured leaf area) increased with decreasing pH levels of acid mist. 4. Leaf tissue injury seemed to be related with the wettability of the leaf surface. Measurement of diameter of water-droplets on the leaf surface might be useful criteria for acid rain or acid mist injury for the glabrous leaved species, such as, Cercis chinensis, Sophora japonica, etc.

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Antioxidant and Tyrosinase Inhibitory Effects of Paeonia suffruticosa Water Extract (목단피 물 추출물의 항산화 및 Tyrosinase 억제효과)

  • You, Jin-Kyoun;Chung, Mi-Ja;Kim, Dae-Jung;Seo, Dong-Joo;Park, Jeong-Hae;Kim, Tae-Woo;Choe, Myeon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.3
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    • pp.292-296
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    • 2009
  • Tyrosinase catalyzes melanin synthesis in skin melanocytes. The effects of Paeonia sufficinalis water extract (MDP) on antioxidant and tyrosinase activities have been studied in a cell-free system and mouse melanoma B16 cell. Radical scavenging activity of MDP was tested by DPPH assay and it showed high DPPH radical scavenging activity. The cellular tyrosinase activity was measured in mouse melanoma B16 cell by RT-PCR and enzyme activity. Treatment with MDP for 24 hr resulted in decreased tyrosinase mRNA level. Tyrosinase activity was decreased, compared with control, in cells exposed to MDP. Thus, Paeonia sufficinalis water extracts may be a candidate for cosmetic use.

Effects of Phytoncide Treatment on the Physicochemical, Microbiological, and Sensory Characteristics of Fresh-cut Lettuce (Phytoncide 처리가 신선편이 양상추의 저장 중 이화학적, 미생물학적 및 관능적 특성에 미치는 영향)

  • Kim, Do-Hee;Kim, Han-Bit;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.20 no.2
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    • pp.166-172
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    • 2013
  • The effect of phytoncide solution treatment on the browning and quality of fresh-cut iceberg lettuce during storage was studied. The treatments were applied as four solutions adjusted at $10^{\circ}C$: distilled water (DW) as the control; edible ethanol (EE); 1% (v/v) phytoncide essential oil from pine needle diluted with distilled water (DP); and 1% (v/v) phytoncide essential oil diluted with edible ethanol (EP). Fresh-cut lettuce was dipped in each solution for 60 sec, was rinsed with distilled water, was packaged with an OPP film bag, and was then stored at $4^{\circ}C$ for 12 days. The EP group had a significantly high level of total soluble solids, titratable acidity, and carbon dioxide, and low total bacteria counts, pH, and oxygen. The sensory score of color in the EP group recorded a high value, but the EE and EP groups recorded low scores in aroma and taste during the storage period. Alcohol and phytoncide were vaporized by opening the package for two hours, and the score of the aroma and taste of EP showed no differences from those of the other groups. Based on the above results, it was determined that the phytoncide essential oil diluted in edible alcohol with 1% solution inhibited the browning of and microbial growth in fresh-cut lettuce, and will be a useful natural compound in maintaining the quality of fresh-cut produce.

Repeated Intramuscular-dose Toxicity Test of Water-soluble Carthami Flos (WCF) Pharmacopuncture in Sprague-Dawley Rats

  • Choi, Yoo-Min;Jung, Da-Jung;Kim, Seok-Hee;Kim, Jong-Uk;Yook, Tae-Han
    • Journal of Pharmacopuncture
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    • v.18 no.1
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    • pp.36-43
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    • 2015
  • Objectives: Water-soluble carthami flos (WCF) is a new mixture of Carthami flos (CF) pharmacopuncture. We conducted a 4-week toxicity test of repeated intramuscular injections of WCF in Sprague-Dawley rats. Methods: Forty male and 40 female rats were divided into 4 groups of 10 male and 10 female SD rats: The control group received 0.5 mL/animal/day of normal saline whereas the three experimental groups received WCF at doses of 0.125, 0.25, and 0.5 mL/animal/day, respectively. For 4 weeks, the solutions were injected into the femoral muscle of the rats alternating from side to side. Clinical signs, body weights, and food consumption were observed; opthalmological examinations and urinalyses were performed. On day 29, blood samples were taken for hematological and clinical chemistry analyses. Then, necropsy was conducted in all animals to observe weights and external and histopathological changes in the bodily organs. All data were tested using a statistical analysis system (SAS). Results: No deaths were observed. Temporary irregular respiration was observed in male rats of the experimental group for the first 10 days. Body weights, food consumptions, opthalmological examinations, urinalyses, clinical chemistry analyses, organ weights and necropsy produced no findings with toxicological meaning. In the hematological analysis, delay of prothrombin time (PT) was observed in male rats of the 0.25- and the 0.5-mL/animal/day groups. In the histopathological test, a dose-dependent inflammatory cell infiltration into the fascia and panniculitis in perimuscular tissues was observed in all animals of the experimental groups. However, those symptoms were limited to local injection points. No toxicological meanings, except localized changes, were noted. Conclusion: WCF solution has no significant toxicological meaning, but does produce localized symptoms. No observed adverse effect level (NOAEL) of WCF in male and female rats is expected for doses over 0.5 mL/animal/day.

Improvement study of river-crossing structures in geyongnam prefecture (경남의 지방하천에 설치된 하천횡단구조물의 현황과 개선방안)

  • Kim, Ki-Heung;Lee, Hyeong-Rae;Jung, Hea-Reyn
    • Journal of Korea Water Resources Association
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    • v.49 no.10
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    • pp.809-821
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    • 2016
  • The study area is local river of 671 (total length 3,741 km) in Gyeongnam prefecture, the results are as follows. Total number of river-crossing structures was investigated as 7,730, and it was found that structures were installed in 2.1 sites per 1 km (river length) on average. Diversion weirs for agriculture were 4006 (51.82%) and drop structures for channel bed maintenance were 3670 (47.48%), but the rest (riverbed road etc.) were 54 (0.70%). The number of high structures (height > 1.0 m) that affect many impact in upstream and downstream was investigated as 3,897 (51%), and the number of low structures (height < 0.5 m) that affect negligibly was 1109 (14%). Fish ladders have been installed on 640 (8%) structures in 153 (23%) rivers. In flood control and environment conservation, river-crossing structures brought about various impact that flood water level is raises and the eco-corridor is intercept. In order to improve these problems, we proposed a few engineering measures that can be realize with respect to river-crossing structures.