• Title/Summary/Keyword: Water loss

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The Determination of Resolution for Quantification of Soil Loss in GIS Environment (GIS 기반에서 토양침식의 정량화를 위한 해상도 결정에 관한 연구)

  • 장영률;이근상;조기성
    • Spatial Information Research
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    • v.10 no.2
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    • pp.301-316
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    • 2002
  • Soil Loss by outflow of water or rainfall has caused many environmental problems as declining agricultural productivity, damaging pasture and preventing flow of water. Also, validity pondage of reservoir or dam is decreased by rivers inflow of eroded soil. Revised Universal Soil Loss Equation(RUSLE) is mainly used to presume soil loss amount of basin using GIS. But, because comparison with survey data is difficult, it is no large meaning that estimate calculated soil loss amount as quantitative. This research used unit sediment deposit survey data of Bo-seong basin for quantitative conclusion of soil loss amount that calculate on RUSLE. Through comparison examination with unit sediment yield that calculate on RUSLE and unit sediment deposit survey data, we can estimate resolution far RUSLE Model. As a result, cell size of 150m was estimated by thing which is most suitable.

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Effects of Aeration of Sawdust Cultivation Bags on Hyphal Growth of Lentinula edodes

  • Lee, Hwa-Yong;Ham, Eun-Ju;Yoo, Young-Jin;Kim, Eui-Sung;Shim, Kyu-Kwang;Kim, Myung-Kon;Koo, Chang-Duck
    • Mycobiology
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    • v.40 no.3
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    • pp.164-167
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    • 2012
  • The effects of aeration through lid filters on the hyphal growth of Lentinula edodes (oak mushroom) in sawdust cultivation bags were investigated. The aeration treatment levels were traditional 27 mm hole cotton plugs, cotton balls and combinations of seven hole sizes ${\times}$ two hole positions (up and under) in the lids covering plastic bags containing 1.4 kg sawdust medium at 63% moisture that had been autoclaved for one hour and inoculated with sawdust spawn of L. edodes strain 921. Aeration treatment effects were measured based on the $CO_2$ concentration at the 15th wk, as well as the hyphal growth rate and degree of weight loss of bags every 14 days for 15 wk. In bags with traditional cotton plugs, the $CO_2$ concentration was $3.8{\pm}1.3%$, daily mean hyphal growth was $2.3{\pm}0.6mm$ and daily mean weight loss was $0.84{\pm}0.26g$. In the bags with 15 mm diameter holes, the $CO_2$ concentration was $6.0{\pm}1.6%$, daily hyphal growth was $2.8{\pm}0.2mm$ and daily weight loss was $0.86{\pm}0.4g$. The bags with 15 mm holes had a higher $CO_2$ concentration and lower water loss than bags with other hole sizes, but the hyphal growth was not significantly different from that of other bags. The weight loss of bags increased proportionally relative to the lid hole sizes. Taken together, these results indicate that traditional cotton plugs are economically efficient, but 15 mm hole lids are the most efficient at maintaining hyphal growth and controlling water loss while allowing $CO_2$ emissions.

Heat transport characteristics by heat generation of electrochemical reactions in proton exchange membrane fuel cell (고분자전해질 연료전지에서 전기화학반응 열생성에 의한 열전달특성)

  • Cho, Son-Ah;Lee, Pil-Hyong;Han, Sang-Seok;Hwang, Sang-Soon
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3377-3382
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    • 2007
  • In proton exchange membrane fuel cell, the heat is generated at the catalyst layer as result of exothermic electrochemical reaction. This heat increases temperature of gas diffusion layer and membrane whose conductivity is very sensitive to humidity, function of temperature. So it is very important to analysis heat transfer through fuel cell to maintain temperature at specified range. In this paper numerical simulation was done including reversible, irreversible, ionic resistance, water formation loss to source term of energy equation. Results show that irreversible and water formation loss contributes mainly to energy source term and as current density increases, all of energy source terms become increased and Nusselt number is increased as results of more heat generation. Particularly irreversible loss is found to be predominant among the all energy source and water formation at cathode channel influences the temperature distribution of fuel cell greatly.

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Effects of Test Temperature on the Reciprocating Wear of Steam Generator Tubes

  • Hong, J.K.;Kim, I.S.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.379-380
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    • 2002
  • Steam generators (S/G) of pressurized water reactors are large heat exchangers that use the heat from the primary reactor coolant to make steam in the secondary side for driving turbine generators. Reciprocating sliding wear experiments have been performed to examine the wear properties of Incoloy 800 and Inconel 690 steam generator tubes in high temperature water. In present study, the test rig was designed to examine the reciprocating and rolling wear properties in high temperature (room temperature - $300^{\circ}C$) water. The test was performed at constant applied load and sliding distance to investigate the effect of test temperature on wear properties of steam generator tube materials. To investigate the wear mechanism of material, the worn surfaces were observed using scanning electron microscopy. At $290^{\circ}C$, wear rate of Inconel 690 was higher than that of Incoloy 800. It was assumed to be resulted from the oxide layer property difference due to the a\loy composition difference. Between 25 and $150^{\circ}C$ the wear loss increased with increasing temperature. Beyond $150^{\circ}C$, the wear loss decreased with increasing temperature. The wear loss change with temperature were due to the formation of wear protective oxide layer. From the worn surface observation, texture patterns and wear particle layers were found. As test temperature increased, the proportion of particle layer increased.

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Pilot Clinical Trial to Evaluate the Efficacy of Acupuncture Therapy on TEWL and Skin hydration (침시술이 경피수분 손실량과 피부 수분함유량에 미치는 임상적 연구)

  • Park, Soo Yeon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.32 no.4
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    • pp.271-276
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    • 2018
  • The purpose of pilot clinical trial is to evaluate the efficacy and safety of acupuncture therapy on TEWL(Transepidermal Water Loss) and skin hydration. A total of 36 human who visited Dongshin University Oriental Medical Center from October 2nd, 2015 to July 31st, 2016 were included in the pilot clinical trial. Acupuncture therapy was performed at Gokji(LI11) and Daechu(GV14). We observed change of TEWL(Transepidermal Water Loss), skin hydration before and after acupuncture therapy. In the primary endpoint, index of TEWL showed a statistically significant decline($8.01{\pm}2.55{\rightarrow}6.58{\pm}1.97g/h/m2$, $7.40{\pm}2.65{\rightarrow}4.99{\pm}1.89g/h/m2$). Index of skin hydration showed statistical significance($52.83{\pm}6.53{\rightarrow}56.82{\pm}7.24$, $63.50{\pm}8.57{\rightarrow}64.96{\pm}8.48$). To evaluate the safety, vital sign check were conducted and showed no statistically significant result. And there were no severe adverse events during this study. According to the above pilot clinical trial, it is suggested acupuncture therapy were effective for skin moisturizing.

The study on the factors which improve skin barrier recovery (피부장벽회복에 영향을 미치는 인자에 관한 연구)

  • Cha, Jae-Hoon;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.21 no.2
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    • pp.39-45
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    • 2008
  • Objective : Skin barrier protects skin against harmful environment. Its function includes antimicrobial barrier as well as physical barrier. But there are few studies about the factors which improve skin barrier recovery after injury. The aim of this study is to investigate the factors which improve skin barrier recovery. Method : Nine hairless mice was anesthetized by inhalation and we tape stripped them. We used thermometer to know temperature one day ago, before anesthesia, before tape stripping, and after tape stripping. Vapometer was used to know transepidermal water loss before tape stripping, after tape stripping. And we used doppler flowmeter to measure blood flow before tape stripping, after tape stripping. Result : After analyzed data, we concluded that temperature was lower after anesthesia than before anesthesia and after tape stripping than before tape stripping. We could know that transepidermal water loss was lower after tape stripping than before tape stripping and more blood flowed after tape stripping. Conclusion : In our study, it was observed that temperature, transepidermal water loss, blood flow changed after tape stripping. But we thought lowered temperature was pathologic situation, more blood flow was to recover after injury. In traditional korean medicine, cold(寒) and imbalance of blood flow(血行) don't only make many skin diseases, but cold(寒) also obstructs blood flow. So we need to study how to warm cold(寒) and improve blood flow.

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ESTIMATION OF LONG-TERM POLLUTANT REMOVAL EFFICIENCIES OF WET RETENTION/DETENTION BASINS USING THE WEANES MODEL

  • Youn, Chi-Hyueon;Pandit, Ashok;Cho, Han-Bum
    • Proceedings of the Korea Water Resources Association Conference
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    • 2005.05b
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    • pp.215-219
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    • 2005
  • A macro spreadsheet model, WEANES (Wet Pond Annual Efficiency Simulation Model), has been developed to predict the long-term or annual removal efficiencies of wet retention/detention basins. The model uses historical, site-specific, multi-year, rainfall data, usually available from a nearby National Oceanic and Atmospheric Administration (NOAA) climatological station to estimate basin efficiencies which are calculated based on annual mass loads. Other required input parameters are: 1) watershed parameters; drainage area, pervious curve number, directly connected impervious area, and ti me of concentration, 2) pond parameters; control and overflow elevations, pond side slopes, surface areas at control elevation and pond bottom; 3) outlet structure parameters; 4) pollutant event mean concentrations; and 5) pond loss rate which is defined as the net loss due to evaporation, infiltration and water reuse. The model offers default options for parameters such as pollutant event mean concentrations and pond loss rate. The model can serve as a design, planning, and permitting tool for consulting engineers, planners and government regulators.

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Reflection and Dissipation Characteristics of Non-overtopping Quarter Circle Breakwater with Low-mound Rubble Base

  • Balakrishna, K;Hegde, Arkal Vittal;Binumol, S
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.1
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    • pp.44-54
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    • 2015
  • Breakwaters are the coastal structures constructed either perpendicular (shore connected) or parallel (detached) to the coast. The main function of breakwater is to create a tranquil medium on its leeside by reflecting the waves and also dissipating the wave energy arriving from seaside, resulting in ease of manoeuvrability to boats or ships to their berthing places. Different types of breakwaters are being used at present, such as rubble mound breakwater, vertical wall type breakwater and composite breakwater. The objective of this paper is to investigate reflection coefficients (Kr) and dissipation (loss) coefficients (Kl) for physical models of Quarter circle caisson breakwater of three different radii of 0.550 m, 0.575 m and 0.600 m with S/D ratio of 2.5 (S=spacing between perforations, D=diameter of perforations). The models were tested in the monochromatic wave flume of the department, for different incident wave heights (Hi), Wave periods (T) and water depths (d). It was observed that reflection coefficient increased with increase in the wave steepness (Hi/gT2) and decreased with increase in depth parameter (d/gT2) and hs/d (Height of structure including rubble base/depth of water). The loss coefficient decreased with increase in the wave steepness and increased with increase in depth parameter and hs/d.

Seasonal Variation of the Surface Heat Budget in the Gumi Reservoir of Nakdong River (낙동강 구미 보의 수면 열수지 계절 변화)

  • Kim, Hak-Yun;Seo, Kwang-Su;Cho, Chang-Bum;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.25 no.8
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    • pp.1057-1063
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    • 2016
  • The heat budget is investigated in the Gumi Reservoir of the Nakdong river. In warm climate season, solar radiation effects play a important role in the change of water temperature. The features of the surface heat balance are almost derived by the latent heat flux and the solar radiation flux. On the other hand, in cold climate season, change of heat stored in the water is mainly dominated by latent and sensible heat transfer between water and air, since flux of solar radiation and loss of outgoing long wave radiation balance approximately. For the annual averages, net flux of radiation, evaporation(latent heat) loss are dominant in the Gumi reservoir. The evaporation losses are dominant from spring to early winter. This means that the Gumi reservoir rolls like a lake of thermal medium or deep depth.

A study of the relationship between Sedimentation and Storage requirments of reservoirs (저수지 내용적 감소가 필요저수량에 미치는 영향에 관한 연구)

  • 신일선;김재곤;김시원
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.21 no.1
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    • pp.53-62
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    • 1979
  • Since the first installation of irrigation Systems in Korea , a large number of small and medium sized reservoirs have been constructed as the main water sources Some 412, 000 ha are at present irrigated from these sources of supply. Many of the reservoirs were designed in accordance with old low standards and have in addition suffered a loss in capacity through sedimentation. At the same time, water demand has increased with the in troduction of high yielding varieties of rice. The combination has resulted in severe water deficits. To study the problem, 16 sample reservoirs have been surveyed and analysed. The results of the study are summarized be low: 1. Average decrease in reservoir capacity from the installation to present-8% 2. Average soil erosion loss (m$^3$/km$^2$/year) is 536 m$^3$/km$^2$/year and average erosion depth of soil is 0. 5mm per year. 3. No relationship, between reservoir capacity per unit of watershed (m$^3$/km$^2$) and soil erosion loss was found. 4. Increases are required in reservoir capacity: 15.8% due to the introduction of HYV's; 16.6% due to the change of system losses from 10%to 25% The conclusion to be drawn from the above results is that existing reservoir capacity should be increased by an average of 32%. The unit storage capacity to be adopted should be 661 mm

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