• Title/Summary/Keyword: water control

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Development of Temperature Control Technology of Root Zone using Evaporative Cooling Methods in the Strawberry Hydroponics (증발 냉각방식을 이용한 딸기 수경재배의 배지 온도조절 기술 개발)

  • Kim, Ki-Dong;Ha, Yu-Shin;Lee, Ki-Myung;Park, Dae-Heum;Kwon, Soon-Gu;Park, Jong-Min;Chung, Sung-Won
    • Journal of Bio-Environment Control
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    • v.19 no.4
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    • pp.183-188
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    • 2010
  • It is necessary to develop an efficient and affordable cooling technology and apply the practical system to rural farmhouse, control to adequate growth environment by adjusting temperature of root zone. A study on managing medium temperature of the hydroponics for strawberry cultivation was conducted and feasible evaporative cooling system for the media cooling were as follows: Characteristics of temperature drop were investigated for the evaporative cooling devices using microporous film duct, felt mulching on media surface, and water permeable sheet in culture tank. The evaporative device with water permeable sheet in culture tank was the most efficient and economic on media cooling system.

Effects of Porcine Placenta Extract Ingestion on Ultraviolet B-induced Skin Damage in Hairless Mice

  • Hong, Ki-Bae;Park, Yooheon;Kim, Jae Hwan;Kim, Jin Man;Suh, Hyung Joo
    • Food Science of Animal Resources
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    • v.35 no.3
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    • pp.413-420
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    • 2015
  • The aim of our study was to evaluate the potential benefits of an oral supplement containing porcine placenta extract (PPE) on skin parameters related to cutaneous physiology and aging. PPEs were administered orally to hairless mice for 12 wk. The effects of oral PPE administration on skin water-holding capacity and Transepidermal Water Loss (TEWL) were similar to those of oral collagen (HYCPU2) administered as a positive control. Magnified photographs and replica images showed a reduction in UVB-induced wrinkle formation after collagen and PPE treatments. PPE treatments ameliorated the thicker skin surface that results from UVB exposure, based on a histological examination of skin tissue. The groups that were orally administered PPE (0.05%, OL; 0.1%, OH group) showed significantly reduced Matrix Metaloproteinase-2 (MMP-2) mRNA expression levels compared with the UVB control (Con), by 33.5% and 35.2%, respectively. The mRNA expression of another collagen-degrading protein, MMP-9, was also significantly lower in the groups that received oral administration of PPE (especially in the OH group) than in the control group. Additionally, oral administration of PPE significantly upregulated tissue inhibitor of metalloproteinase-1 (TIMP-1) and -2 mRNA expression levels compared with expression levels in the control group (p<0.05). This indicates that orally administered PPE activated the expression of Timp-1 and -2, inhibitors of MMP, which is responsible for collagen degradation in skin. Taken together, we propose that long-term oral administration of PPE might have a beneficial effect with respect to skin photo-aging.

PARAMETRIC STUDIES ON THERMAL HYDRAULIC CHARACTERISTICS FOR TRANSIENT OPERATIONS OF AN INTEGRAL TYPE REACTOR

  • Choi, Ki-Yong;Park, Hyun-Sik;Cho, Seok;Yi, Sung-Jae;Park, Choon-Kyung;Song, Chul-Hwa;Chung, Moon-Ki
    • Nuclear Engineering and Technology
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    • v.38 no.2
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    • pp.185-194
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    • 2006
  • Transient operations for an integral type reactor, SMART-P, have been experimentally investigated using a thermal-hydraulic integral test facility, VISTA (Experimental Verification by Integral Simulation of Transients and Accidents), in order to verify the system design and performance of the SMART-P, a pilot plant of SMART. The VISTA facility was subjected to various accident conditions such as feedwater increase and decrease, loss of coolant flow, and control rod withdrawal accidents in order to elucidate the thermal-hydraulic responses following such accidents and finally to verify the system design of the SMARTP. Full functional control logics have been implemented in the VISTA facility in order to control the required control action for an accident simulation. As one of the sensitivity tests to verify the PRHRS performance, the effects of the initial water level in the compensation tank are experimentally investigated. When the initial water level is 16%, the water is quickly drained and nitrogen gas is then introduced into the PRHR system, resulting in deterioration of the PRHRS performance. It is thus found that nitrogen ingression should be prevented to ensure stable PRHRS operation.

Effect of Dietary Supplementation with Citrus By-product as a Vitamin C Replacement for Juvenile Olive Flounder Paralichthys olivaceus at Low Water Temperatures (저수온기 치어기 넙치(Paralichthys olivaceus) 사료 내 비타민 C 대체제로서 감귤착즙박의 이용 가능성 및 항생제 대체 효과)

  • Kim, Youjeong;Lee, Chorong;Shin, Jaehyeong;Lee, Kyeong-Jun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.1
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    • pp.15-24
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    • 2017
  • This study examined the effects of dietary supplementation with citrus by-product (CBP) on the growth, feed utilization, innate immunity, and histology of the gills and intestine of juvenile olive flounder Paralichthys olivaceus during low water temperature season. A vitamin C-free basal diet was regarded as a control and five other diets were formulated that contained 30 and 300 mg of L-ascorbyl-2-polyphosphate (LAPP) or CBP as vitamin C equivalents/kg diet, or the antibiotic oxytetracycline (OTC) (designated as control, LAPP30, LAPP300, CBP30, CBP300, and OTC, respectively). Olive flounder (initial body weight $44.6{\pm}0.32g$) were fed the six experimental diets to apparent satiation for 9 weeks. Growth and feed utilization were significantly higher in CBP30 than in the control and LAPP groups. The lysozyme activity was significantly higher in CBP30 than in LAPP300. Enterocyte height was significantly higher in CBP30 than in the control. The number of goblet cells was increased significantly with LAPP30, LAPP300, and CBP30. These results demonstrate that CBP can reduce or replace vitamin C and antibiotic in the diet of olive flounder during the low-water-temperature season. The optimal CBP supplementation level seems to be approximately 1%, which is equivalent to 30 ppm vitamin C/kg in the fish diet.

Study on the IPMC electrical characteristic change For the utilization of Ocean Current Energy (해양 에너지 활용을 위한 IPMC의 전기적 특성 변화 연구)

  • Son, Kyung Min;Kim, Min;Kim, Gwan-Hyung;Kim, Hyun-jo;Byun, Gi-Sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.531-533
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    • 2013
  • In this paper, to study the IPMC (Ionic exchange Polymer Metal Composite) material consisting of a sulfonic acid ion and fluoride combination of carbon with Nafion film greatly affected the electro-active polymer (Electro Active Polymer) characteristics and the presence of water and cationshave properties. Use or electrical energy into mechanical energy, mechanical energy, electrical energy, and can be utilized to its characteristics, depending on the water and cations in water varies greatly. Configure the device simulations in order to study the electrical properties of these IPMC. Stepper Motor using MCU and simulator designed for the electrical characterization due to the movement and to the implementation of the mechanical movement of ocean currents. In this study, configuration the IPMC and simulation device to the area of the IPMC to the efficient use of energy currents, frequency, salinity concentration, through the efficient use of the IPMC due to the bend angle of the electrical analysis and research methods we propose.

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Effect of Algal Bloom Control Using the Mesocosms Installed with Zooplankton, Fishes, Aquatic Macrophytes and Artificial Marshy Land in Kyungan Stream (경기도 경안천에 설치한 메소코즘 내에서의 동물플랑크톤, 어류, 수생식물, 인공식물섬에 의한 조류저감효과 연구)

  • Song, Mi-Ae;Kong, Dong-Soo;Lee, Ok-Min
    • Journal of Korean Society on Water Environment
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    • v.29 no.5
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    • pp.641-647
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    • 2013
  • We installed mesocosms including zooplankton, fishs, artificial marshy land and aquatic macrophytes in Kyoungan stream to study the reduction effects of algae from Sep. 16 to Oct. 28, 2011. The control tendency of phytoplankton taxa was compared by analyzing community structure and dominant species in each mesocosm. Under the condition where Bluegill was absent, Daphnia similoides showed good effect of algal control since it has large food area and has high grazing pressure. Bluegill selectively preys upon large zooplankton, Daphnia similoides, as it also preys on small zooplanktons that flow in. In condition that Bluegill was absent, Daphnia similoides preyed selectively large phytoplankton (Cryptomonas ovata). Due to the shading of light, removal of nutrients and providing refuge for small zooplanktons, aquatic macrophytes and artificial marshy land showed high level of algal control. In corrals with aquatic macrophytes and artificial marshy land, the dominancy of genus Coelastrum and Pediastrum, which are difficult for small zooplanktons to feed on, relatively increased. In conclusion, under conditions of small number of predators such as Bluegill, Daphnia similoides is thought to be useful in algal bloom; however, when lots of predators are present, using small sized zooplanktons along with artificial marshy land and aquatic macrophytes is thought to be more useful than using large zooplanktons.

Epidemiology and Control of Strawberry Bacterial Angular Leaf Spot Disease Caused by Xanthomonas fragariae

  • Kim, Da-Ran;Gang, Gun-hye;Jeon, Chang-Wook;Kang, Nam Jun;Lee, Sang-woo;Kwak, Youn-Sig
    • The Plant Pathology Journal
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    • v.32 no.4
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    • pp.290-299
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    • 2016
  • Strawberry bacterial angular leaf spot (ALS) disease, caused by Xanthomonas fragariae has become increasingly problematic in the strawberry agro-industry. ALS causes small angular water-soaked lesions to develop on the abaxial leaf surface. Studies reported optimum temperature conditions for X. fragariae are $20^{\circ}C$ and the pathogen suffers mortality above $32^{\circ}C$. However, at the nursery stage, disease symptoms have been observed under high temperature conditions. In the present study, results showed X. fragariae transmission was via infected maternal plants, precipitation, and sprinkler irrigation systems. Systemic infections were detected using X. fragariae specific primers 245A/B and 295A/B, where 300-bp and 615-bp were respectively amplified. During the nursery stage (from May to August), the pathogen was PCR detected only in maternal plants, but not in soil or irrigation water through the nursery stage. During the cultivation period, from September to March, the pathogen was detected in maternal plants, progeny, and soil, but not in water. Additionally, un-infected plants, when planted with infected plants were positive for X. fragariae via PCR at the late cultivation stage. Chemical control for X. fragariae with oxolinic acid showed 87% control effects against the disease during the nursery period, in contrast to validamycin-A, which exhibited increased efficacy against the disease during the cultivation stage (control effect 95%). To our knowledge, this is the first epidemiological study of X. fragariae in Korean strawberry fields.

Study on the Effect of Chaenomelis Fructus.Herba Chelidonii.Clematis Florida Thunb on Inflammation and Liver Function of Rats with Arthritis (관절염 백서의 염증과 간기능에 대한 목과.백굴채.위영선(木瓜.白屈菜.威靈仙)의 효능연구)

  • Park Jae-Seok;Kim Youn-Sub
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.6
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    • pp.1610-1614
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    • 2005
  • The purpose of this study is to observe the effects of Chaenomelis Fructus Herba Chelidonii Clematis Florida Thunb mixed water extract on the inflammatory edema induced by Found's complete adjuvant and on different blood volume, and then to demonstrate its efficiencies as well as its safety. We injected Chaenomelis Fructus Herba Chelidonii Clematis Florida Thunb mixed water extract on the inflammatory edema induced by Found's complete adjuvant once daily at the same time for a week, then observed the paw-edema, the counts of the blood WBC, Serum total protein, Serum total bilirrubin, SGOT and SGPT The result obtained is as follows : Inflammatory edema on the right plantar in both sample groups showed a significant reduce compared with that in the control group. The counts of WBC in both sample groups showed a significant decrease compared with that in the control group. The volume of serum total protein in the Sample A group showed a significant decrease compared with that in the control group. The volume of serum total bilirrubin, GOT and GPT in both sample groups was not changed compared with that in the control group. As a result of this experiment, it is concluded that Chaenomelis Fructus Herba Chelidonii Clematis Florida Thunb mixed water extract showed that therapeutic effect on the anti-inflammation on arthritis; otherwise it showed non-toxic effect on the liver function.

Effects of pH Control Agent and Co-Precipitate Washing Agent on Nickel Ferrite Preparation by Co-Precipitation Method (공침법에 의한 Nickel Ferrite의 분말제조에서 pH-조절제 및 공침물-세척제의 영향)

  • Jeong, Hong-Ho;Seong, Gi-Ung
    • Korean Journal of Materials Research
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    • v.10 no.6
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    • pp.445-449
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    • 2000
  • Nickel ferrite $(Ni_{0.75}Fe_{2.25}O_4$ was synthesized by co-precipitation method in order to investigate its behavior under conditions of the reactor coolant system in pressurized light water nuclear power plants. Ammonia or potassium carbonate was used as a solution pH control agent, and aqueous ammonia or potassium carbonate solution or secondary distilled water was used as a co-precipitate washing agent. The effects of the pH control agent and the co-precipitate washing agent on the production yield on the basis of the Ni/Fe molar ratio and the particle characteristics of final products were investigated by XRD, SEM, EDX and XPS. The production yield was almost congruent with that of the initial aqueous mixture in case of using potassium carbonate as a pH control agent, while in case of using ammonia, it was quite changed. The difference seemed to be due to the effects of $Ni^{2+}{\leftarrow}NH_3$complexation in the aqueous solution and of the pH of co-precipitate washing agent.

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Eco-frendly Control of Culex pipiens (mosquito) Larvae by Acorus calamus (sweet flag) and Acorus gramineus (Grassy-leaved sweet flag) Extracts

  • Choi, Jeong-Keun;Lee, Ji-Yeon;Lee, Ja-Hyun;Lee, Seong-Gene;Han, Yeon-Soo;Han, Tae-Ho
    • Korean Journal of Plant Resources
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    • v.19 no.6
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    • pp.721-726
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    • 2006
  • Mosquitoes are carriers of malaria and encephalitis. This study performed for eco-friendly control of mosquitos by using genus Acorus. Several solvents were used for the extraction of genus Acorus; water, ethanol, and methanol. Grinded leaves and roots were also included. Acorus extracts killed mosquito larvae and the ethanol extract showed the best result. Autoclaved Acorus water needed long time to kill mosquito larvae. $LT_{50}$ of 1 % Acorus calamus decoction was 13.6 hrs and 1 % autoclaved Acorus water was 53.6 hrs. $LT_{50}$ of 0.05% Acorus calamus rhizome powder was 28.5 hrs. $LT_{50}$ of 0.5% Acorus calamus leaf powder was 10.8 hrs. $LT_{50}$ of 0.1 % Acorus calamus decoction was 63.4 hrs and 0.1 % Acorus calamus ethanol extracts was 48.6 hrs and 0.1% Acorus calamus methanol extracts was 53.9 hrs. $LT_{50}$ of 0.4% Acorus gramineus decoction was 45.5 hrs, 0.4% ethanol extracts was 10.9 hrs, 0.4% methanol extracts was 10.2 hrs. $LT_{50}$ of ethanol extracts was shorter than other extracts. Acorus calamus rhizome powder could be used for the eco-friendly control of the mosquito larvae.