• Title/Summary/Keyword: 교환시기

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The status of care for Soft Contact Lens and periodic examination (연성 콘택트렌즈의 관리 및 정기검사 실태)

  • Shin, Jang Cheol
    • Journal of Korean Ophthalmic Optics Society
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    • v.5 no.2
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    • pp.107-113
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    • 2000
  • This study has analyzed soft contact lens care-after-sale and periodic examinations at optical shops and eye clinics. And I wish to make that use of educational data for the soft contact lens lesson of the department of ocular optics. This questionnaire studied the status of care for soft contact lens and periodic examination, of students who wears soft contact lens. The results are as follows: First, 7.5% of students questioned wore soft contact lens. More women than men wore soft contact lens. The soft contact lens wearers purchased lens mainly at optical shops. 78.5% of them wore daily wear lens. Because of cosmetic advantages of soft contact lens. 47.9% of them wore soft contact lens. 72.5% of them wore soft contact lens less than 12 hours per a day. 32.0% of them has worn soft contact lens more than 6 months less than 1 year. 51.1% of them experienced irritation. 39.7% of them have exchanged soft contact lens between 6 and 9 months. Secondly, when purchasing lenses. 60% of soft contact lens wearers were given instructions of general care, such as duration of wearing lens, how to remove protein, how to store, and how to sterilize at both of eye clinics and optical shops. But the proportion of instructions, such as side effects and periodic examination which were given to soft contact lens wearers, is lower both at eye clinics and optical shops. Especially at optical shops, the proportion of instruction for periodic examination, is lower than at eye clinics(p<0.05). Thirdly, The proportion of operations of periodic examinations after use of soft contact lens both at eye clinics and optical shops, is low. The soft contact lens wearers have had more periodic examinations at eye clinics than at optical shops. But the rate of non-periodic examination at optical shop is 87.9%. And for periodic examinations, general care was done at optical shops. On the other hand, eye examinations, general care, and treatments were done more at eye clinics. Fourthly, 60.3% of the soft contact lens wearers understood the necessity of the periodic examinations, but actually, only 6.4% of them were given the schedule for the periodic examinations, and 2.5% of them were given at an optical shop(p<0.01).

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Mass Balance of Salts, DIP, DIN and DON in the Gomso Tidal Flat (곰소만 조간대에서 Salts, DIP, TDN의 물질 수지)

  • Jeong Yong-Hoon;Kim Yeong-Tae;Kim Ki-Hyun;Kim Soh-Young;Kim Byung-Hoon;Yang Jae-Sam
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.11 no.2
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    • pp.68-81
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    • 2006
  • As one of the on-going projects to investigate the biogeochemical characteristics of tidal flat, we develop seasonal mass balance calculations (or DIP, DIN and DON in Gomso Bay. We have obtained 13-hours time-series data of salinity, tidal current, nutrients, and chlorophyll-a of seawater for spring, dry summer, rainy summer and winter during $1999{\sim}2000$. DIP of $-1.10{\times}10^6g\;P\;day^{-1},\;-4.50{\times}10^5g\;P\;day^{-1}$ was out-fluxed from the bay to the bay proper for spring and dry summer, respectively. Whereas $1.06{\times}10^4g\;P\;day^{-1}$ of net influx of DIP was found during winter and $2.72{\times}10^6g\;P\;day^{-1}$ of net influx was also found during the rainy summer. Therefore we suggest the role of Gomso tidal flat as a source of DIP fur the seasons of spring and summer, but as an opposite role during the rainy summer and winter but much smaller in magnitude. Except winter, the advection process by tidal current is found the most dominant flux among the diverse fluxes of DIP in the bay. Whereas ground water is estimated as the strongest flux of TDN except winter. TDN of $1.38{\times}10^7g\;N\;day^{-1},\;2.45{\times}10^6g\;N\;day^{-1},\;and\;4.65{\times}10^7g\;N\;day^{-1}$ was in-fluxed to the bay from the bay proper far spring, rainy summer and summer, respectively. Only $-1.70{\times}10^7g\;N\;day^{-1}$ of net out-flux was found during the winter. Therefore we suggest the role of Gomso tidal flat as a sink of TDN far the year round except winter.

The Physiochemical Characteristics of Seawater and Sediment of Marine Shellfish Farm in Jindong Bay (진동만 패류양식해역의 환경특성)

  • Jeong, Woo-Geon;Cho, Sang-Man
    • The Korean Journal of Malacology
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    • v.19 no.2
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    • pp.161-169
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    • 2003
  • Seawater and sediment quality analysed was calculated to examinate the present environmental characteristics and pollution load was also calculated to evaluate the effect of farming area on the coastal environment. The measurements for seawater quality demonstrate the coastal environment has relatively eutrophicated with significantly decreased DO (0.2-8.5 mg/l) and elevated COD (9.6-31.2 mg/l) in summer. It was also evident that the water quality in Jindong Bay has been influenced by residues tide from Masan Bay with high metal concentration in August of 2002. Annual total pollution load (land and farm-driven) was estimated at 37,316 ton (SS) /yr: 9,809 ton/yr (26.3%) of land-driven load, 23,576 ton/yr (63.2%) of coastal sedimentation and 3,932 ton/yr (10.5%) of feces of cultural organisms. When all ark shell seedling farms are permitted species conversion to ascidian farm, the pollution load would increase by 196%, which may be another source for accelerating the eutrophication of the environment in Jindong Bay.

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Geochemical Studies on Au-Ag Hydrothermal Vein Deposits, Republic of Korea : Goryeong-Waegwan Mineralized Area (한반도(韓半島) 금(金)-은(銀) 열수(熱水) 광상(鑛床)의 지화학적(地化學的) 연구(硏究) : 고령(高靈)-왜관지역(倭館地域) 광화대(鑛化帶))

  • So, Chil-Sup;Choi, Sang-Hoon;Chi, Se-Jung;Choi, Seon-Gyu;Shelton, Kevin L.
    • Economic and Environmental Geology
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    • v.22 no.3
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    • pp.221-235
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    • 1989
  • Gold-silver mineralization of the Goryeong-Waegwan area was deposited in three stages of quartz and calcite veins which fill fissures in Cretaceous sedimentary rocks of the Sindong Group. Radiometric dating indicates that mineralization is Late Cretaceous age(98 Ma) likely associated genetically with intrusion of a small biotite granite stock. Fluid inclusion and stable isotope data indicate that Au-Ag ore was deposited at temperatures between $280^{\circ}C$ and $230^{\circ}C$ from fluids with salinities between 1.7 and 8.7 equiv.wt.% NaCl. Evidence of boiling indicates pressures of <100 bars, corresponding to depths of 425 and 1,150m, respectively, assuming lithostatic and hydrostatic loads. Within ore stage I there is an apparent decrease in ${\delta}^{34}S$ values of $H_2S$ with paragenetic time, from +1.4 to -2.5 per mil. This pattern was likely achieved through progressive increases in pH and activity of oxygen accompanying boiling. Measured and calculated hydrogen and oxygen isotope values of ore-forming fluids(${\delta}D$ = -90 to -100 per mil; ${\delta}^{18}O$ = +3.9 to -11.4 per mil) indicate meteoric water dominance, approaching unex-changed meteoric water values. Au-Ag deposition is thought to be the result of cooling and dilution of a boiling fluid through mixing with less evolved meteoric waters.

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The responses of Growth and Physiological traits of Acer triflorum on Calcium Chloride ($CaCl_2$) Concentration (염화칼슘 농도에 따른 복자기의 생장 및 생리적 반응 특성)

  • Kwon, Min-Young;Kim, Sun-Hee;Sung, Joo-Han
    • Korean Journal of Environment and Ecology
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    • v.28 no.5
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    • pp.500-509
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    • 2014
  • To prevent freezing of the road by fallen snow, Calcium chloride($CaCl_2$) as a deicer is used to very often and it can be harmful to roadside trees. This study was conducted to investigate the effects of Calcium chloride($CaCl_2$) as a deicer on growth and physiological traits of Acer triflorum according to different concentration of $CaCl_2$. We measured growth, chlorophyll contents, gas exchangement characteristics, chlorophyll fluorescence and mineral nutrition concentration in plant and soil. The experimental group was composed of four treatments including 0mM(control), 9mM(0.5 %), 18mM(1.0 %), 54mM(3.0 %). Before germinating new shoot, the dissolution of $CaCl_2$ was irrigated twice interval of a week. At 30 days after treatment, all treatments decreased total cholorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and photochemical efficiency($F_v/F_m$) with increasing concentration of $CaCl_2$ and especially, they significantly reduced in 3.0 % treatment. In contrast, chlorophyll a/b ratio increased with an increase of $CaCl_2$ concentration and water use efficiency increased in 1.0 % and 3.0 % treatments. At 50 days after treatment, all treatments were decreased in chl a, chl b, total chlorophyll content, carotenoid content, photosynthetic capacity, photochemical efficiency($F_v/F_m$) and quantum yield of photosystem II(${\Phi}_{PSII}$) compared with control and 3.0 % treatments were withered. $Ca^{2+}$ and $Cl^-$ were accumulated in leaves and soil, which inhibited water absorption and electron transport and it caused the reduction of height growth rate more than 50 %. Although there was a little difference according to time and $CaCl_2$ concentration, all treatments decreased in growth rate and physiological activity slowed down. As time passed, these results got worse. Therefore we need to take a measure earlier in order to minimize damage of trees.

Physiological Responses of One-year-old Zelkova serrata Makino Seedlings to Ozone in Open-top Chamber (Open-top chamber 내(內)에서 오존에 폭로(暴露)시킨 1년생(年生) 느티나무(Zelkova serrata Makino) 묘목(苗木)의 생리적(生理的) 반응(反應)에 관(關)한 연구(硏究))

  • Kim, Hyun Seok;Lee, Kyung Joon
    • Journal of Korean Society of Forest Science
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    • v.84 no.4
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    • pp.424-431
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    • 1995
  • This study was conducted to evaluate resistance and physiological responses of Zelkova serrata Makino seedlings to ozone in open-top chamber. One-year-old seedlings of Zelkova serrata were planted in pots in April and grown in greenhouse until August. The plants were transferred into two out-door open-top chambers with a dimension of 2.0 m in diameter and 2.0 m in height. First chamber served as a control and was supplied with ambient air. Ozone was added to the second chamber for 5 hours per day(10.00 AM-15.00 PM) for 23 consecutive days at 0.1 ppm. Each chamber housed 70 pots. Every two, three or five days after initiation of exposure, ten pots were randomly removed from the chamber and determined for the contents of chlorophyll a, b, total chlorophyll and ${\beta}$-carotene in the leaves. Photosynthesis and dark respiration were estimated by measuring $CO_2$ absorption in a gas exchange chamber and oxygen absorption by oxygen monitoring system, respectively. Superoxide dismutase(SOD) activity in the leaves was assayed by a xanthine oxidase method. First visible injury of translucent(water-soaked looking) spots appeared on the leaves 14 days after the initial exposure, and ozone accelerated senescence of old leaves. Contents of chlorophyll a and b decreased by 17%, and 31%, respectively, in ozone treatment two days after exposure. The decrease in chlorophyll b was greater than that of chlorophyll a. Content of ${\beta}$-carotene in ozone treatment decreased by 25% two days after initiation of exposure, but the reduction was recovered with time. Photosynthesis decreased by 45%, and the respiration increased by 28% in the ozone treatment. SOD activity started to increase 4 days after beginning of exposure and increased by 285% 7 days after exposure, and decreased to the level below the control treatment with the advancement of the visible injury.

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School Dieticians' Perception of Seafood Ingredient Pricing in School Food-Service in Seoul (학교급식 수산물 가격 결정에 대한 서울 지역 학교영양(교)사의 인식)

  • Cha, Myeong Hwa;Seo, Sang Rok;Moon, Min Ji;Yang, Ji Hye;Sung, Bo Mi;Jung, Hyun Suk;Ryu, Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.11
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    • pp.1766-1773
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    • 2014
  • The purpose of this research was to scrutinize dieticians' perspective of seafood ingredients prices in school food-service. Suppliers' contract status, seafood ingredient usage and satisfaction, expectations regarding prices of seafood ingredients, and willingness to pay when HACCP is taken into account were studied. Through random sampling, the survey was conducted on 231 dieticians in 11 different educational districts and 12 elementary, six middle, and three high schools. Ultimately, 142 survey responses were taken into account. Data analysis was performed using SPSS v15.0 by descriptive analysis, ${\chi}^2$-test, and t-test. For contracts regarding seafood ingredients, competitive contracts composed 79.7%. Exactly 42.1% responded that contracts were breached, and 60.1% testified that product returns were due to excessive glazing of ingredients. The satisfaction rate of 'hygiene & sanitation of product' was the highest, whereas 'price of product' was the lowest. For 'recontracting intention', 'informal purchasing' showed higher rates compared to 'competitive bidding'. Reflecting upon the six main price factors, 'designation and maintenance of HACCP', 'price of raw seafood ingredients', 'processing costs', 'margin', 'logistic costs', and 'cost of standardizing seafood ingredients', dieticians' perceived 'impact on the anticipated price' on total cost was lower than present counterparts. This implicates that 'impact on the present price' of the six price factors is too excessive, suggesting that many dieticians are unsatisfied with the current prices of seafood ingredients. Furthermore, 52.8% of dieticians stated that the maximum additional payment of HACCP seafood ingredients should be less than 5%. Consequently, this research serves as basic information for reasonable pricing of seafood ingredients and contributes to increased seafood usage by school food-services.

Analysis of the Environmental Index and Situation Naturalized Plants in the Stream of Downtown Jeonju (전주 도심 하천의 귀화식물 현황과 환경지수 분석)

  • Oh, Hyun-Kyung;Beon, Mu-Sup
    • Korean Journal of Environmental Biology
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    • v.24 no.3
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    • pp.248-257
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    • 2006
  • Total naturalized plant species in the streams of Jeonju were listed as 109 taxa; 24 families, 75 genera, 106 species, 3 varieties. Dividing by stream, Jeonju stream has 75 taxa; 20 families, 55 genera, 73 species, 2 varieties. Samcheon stream has 86 taxa; 19 families, 64 genera, 84 species, 2 varieties. Soyang stream has 80 taxa; 21 families, 60 genera, 77 species, 3 varieties. Urbanization Index (UI) of total streams (109 taxa) was 40.2%. UI was 27.7% in Jeonju stream (75 taxa), 31.7% in Samcheon stream (86 taxa), 29.5% in Soyang stream (80 taxa). Dividing by degree of naturalization classification, 25 taxa (9.2%) were found in class 5, 17 taxa (6.2%) in class 4, 32 taxa (11.8%) in class 3, 27 taxa (9.9%) in class 2 and 8 taxa (2.9%) in class 1. Dividing by introduction period, 48 taxa (44%) aye in period I, 19 taxa (17%) in period II, 42 taxa (39%) in period III. Dividing by growth type, 48 taxa (44%) are annuals, 25 taxa (23%) are biennials, 33 taxa (30%) are perennials. Dividing by the place of origin, 39 taxa (35%) are from Euyope, 33 taxa (30%) from North America, 11 taxa (10%) from Tropic America, 9 taxa (8%) from Europe Asia,5 taxa (5%) from South America, 5 taxa (5%) from China.

Effective Management of Invasive Nutria (Myocastor coypus) in the UK and the USA (영국과 미국에서 침입성 뉴트리아 (Myocastor coypus)의 효과적 관리)

  • Kil, Jihyon;Lee, Do-hun;Kim, Young-chae
    • Ecology and Resilient Infrastructure
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    • v.2 no.4
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    • pp.265-273
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    • 2015
  • It is the better to take preventative measures against the natural intrusion in advance from invasive alien species that reduce biodiversity and cause economic loss to humans. If the prevention of intrusion and spread fails, we need to make active control and eradication. This study aims to introduce nutria (Myocastor coypus) control cases performed in the United Kingdom and the United States and to provide information for the contribution of nutria management measure improvements. The nutria eradication campaign in the United Kingdom was developed as a long-term plan based on sufficient understanding on the management target and objective and suitable support. Sufficient information on nutria was accumulated and the management strategy was flexibly modified according to the changes in management that were proactively reflected in the field. Regarding the eradication project at Chesapeake Bay in the United States, based on long-term ecological information, more advanced capture technology than in the United Kingdom were introduced and the eradication plan, strategy and implementation were configured by analyzing the strengths and weaknesses of the eradication campaign in the United Kingdom. The successful cases in the United Kingdom and the United State provide an information on how to improv the nutria management measure. For the eradication of nutria, it is necessary to reach a consensus between stakeholders and to form a consultative group between related organizations for periodic communication. Opinions on the field must be actively accepted in the consultation process for strategy and policy decision, and the eradication plan needs to be developed based on a management index. The eradication plan is required to be managed, evaluated and adjusted in a systematic way. Scientific management must be introduced and the management performance must be evaluated objectively so that a practical plan can be flexibly adjusted. It is also required to secure a long-term budget support and a stable organization and to input a concentrated budget at the proper period when there is high efficiency of eradication.

The Budget of Nutrients in the Estuaries Near Mokpo Harbor (목포항 주변 하구역의 영양염 수지)

  • Kim, Yeong-Tae;Choi, Yoon-Seok;Cho, Yoon-Sik;Oh, Hyun-Taik;Jeon, Seung-Ryul;Choi, Yong Hyeon;Han, Hyoung-Kyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.6
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    • pp.708-722
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    • 2016
  • Land-Ocean Interactions in the Coastal Zone (LOICZ) models for nutrient budgets were used to estimate the seasonal capacity of the Youngsan Estuary and Youngam-Geumho Estuary to sink and/or supply nutrients such as dissolved inorganic phosphorus (DIP) and nitrogen (DIN) to provide an understanding of the behavior of the coupled biogeochemical cycles of phosphorus and nitrogen in the estuaries (Youngsan Estuary, Youngam-Geumho Estuary) near Mokpo Harbor. During non-stratified periods (May, September, and November, 2008), simple three-box models were applied in each sub-region of the system, while a two-layer box model was applied during on-site observation of stratification development (July, 2008). The resulting mass-balance calculation indicated that even after large discharges from artificial lakes (in May and July), DIP influxes due to a mixing exchange ($V_{X-3}$, or $V_{deep}$) were more than terrigenous loads, indicating the backward transportation of nutrients from a marine source. The model results also indicated that for nutrient loads (DIP and DIN fluxes) in September, an extreme congestion of nutrients occurred around the mouths (sub-region III of the model) of the estuaries, possibly due to an imbalance in physical circulations between the estuaries and offshore locations. In November, the Youngam-Geumho Estuary, into which freshwater was discharged from artificial lakes (Youngam and Geumho Lake), showed nutrient enrichment in the water column, but the Youngsan Estuary showed nutrient depletion. In conclusion, to efficiently control water quality in the estuaries near Mokpo Harbor, integrated environmental management programs should be implemented. I.e., the reduction of nutrient loads from land basins as well as the deposit of nutrient loads into adjacent coastal lines.