• Title/Summary/Keyword: Field release

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Development Of A Windows-Based Predictive Model For Estimating Sediment Resuspension And Contaminant Release From Dredging Operations

  • Je, Chung-Hwan;Kim, Kyung-Sub
    • Water Engineering Research
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    • v.1 no.2
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    • pp.137-146
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    • 2000
  • A windows-based software package, named DREDGE, is developed for estimating sediment resuspension and contaminant release during dredging operations. DREDGE allows user to enter the necessary dredge information, site characteristics, operational data, and contaminant characteristics, then calculates an array of concentration using the given values. The program mainly consists of the near-field models, which are obtained empirically, for estimating sediment resuspension and the far-field models, which are obtained analytically, for suspended sediment transport. A linear equilibrium partitioning approach is applied to estimate particulate and dissolved contaminant concentrations. This software package which requires only a minimal amount of data consists of three components; user input, tabular output, and graphical output. Combining the near-field and far-field models into a user-friendly windows-based computer program can greatly save dredge operator's, planners', and regulators' efforts for estimating sediment transports and contaminant distribution.

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A Study on the Indicator Development using Industrial Safety Sanitation Field GRI Guideline and Industrial Safety Sanitation Act from Domestic and Overseas Sustainable Management Reports (국내.외 지속가능경영보고서의 산업안전보건 분야의 GRI guideline을 이용한 평가 및 산업안전보건법을 이용한 지표 개발에 관한 연구)

  • Cho, Kee-Hong;Rim, Hwa-Young;Choi, Soon-Young
    • Journal of the Korea Safety Management & Science
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    • v.11 no.4
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    • pp.1-6
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    • 2009
  • This study was evaluated the indicators of GRI guideline LA6-LA9 for industrial safety sanitation field on 22 domestic sustainable management reports and 46 overseas reports published by companies in 2007 and 2008, was developed new indicators with emphasis on industrial safety sanitation act, and was assessed whether they are released. As a result, LA6(Percent of total workforce represented in formal joint management-work health and safety committees that help monitor and advise on occupational health and safety programs) was evaluated highest in release ratio on whether to release the reports by each indicator of industrial safety sanitation field using domestic sustainable management report GRI guideline, and in the case of overseas companies, it was evaluated that there is no companies that release all from LA6 through LA9 among GRI guideline, but it was grasped that the ratio of partial release is high. As for the release of indicators was developed with the use of industrial safety sanitation act of 22 domestic companies, the release of indicator No. 1(report and industrial disaster record) and 10(health diagnosis) of industrial safety sanitation act was high. This study is meaningful in that it analyzed the industrial safety sanitation field of sustainable management report(CSR) that has not been attempted so far with the use of new indicators developed with emphasis on GRI guideline and industrial safety sanitation act.

Effects of Spatio-Temporal Resolution of Diagnostic Wind Field on the Dispersion of Released Substance (바람장의 공간적.시간적 해상도가 누출물질 확산에 미치는 영향)

  • 김영성
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.4
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    • pp.327-338
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    • 2000
  • complexity in atmospheric environment coupled with shoreline and complex terrain often causes local variations of meteorology that are distinct from those representative over larger surrounding area, These kinds of local variations are less significant in usual long-term environmental impact analyses dealing with continuous plume. The variations could however be crucial in predicting dispersion of toxic substance released in a relatively small area for a short duration. In the present paper the effects of spatial and temporal resolution of diagnostic wind field on the dispersion of the released substance are investigated by using a puff model. A hypothetical release scenario assumes that a substance is released from a location in the Yochon Industrial Estate and passively dispersed within a few-kilometer distance for an hour. The results show that diagnostic analysis could resolve more spatial variations to some extent by employing smaller grid size. The peak concentrations and puff trajectories obtained from spatially -and/or tmeporally -varing diagnostic wind field are found appreciably different from those obtained from uniform wind field. Attention to high-resolution wind field in the both spatial and temporal spaces is called in the consequence analysis of toxic substance release.

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Environmental Factors Affecting Ascospore Release of Mcyosphaerella nawae, the Causal Organism of the Spotted Leaf Casting of Persimmon (감나무 둥근무늬낙엽병균(Mycosphaerella nawae)의 자낭포자 비산에 영향을 주는 환경요인)

  • 권진혁;강수웅;정부근;박창석
    • Korean Journal Plant Pathology
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    • v.11 no.4
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    • pp.344-347
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    • 1995
  • Factors affecting on the ascospore release of Mycosphaerella nawae, the causal organism of persimmon leaf casting disease, were investigated. The ascospore release of the pathogen occurred following the precipitation of rain. The ascospore release started from the beginning of raining, reached maximum at 2 hours after the precipitation of rain, and then decreased abruptly. When the inoculum source (a file of infected leaves) was submerged in water to imitate raining conditions, 92.5% of the total ascospores were released within 1 hour after submerging, 5.8% were after 2 hours, 1.4% were after 4 hours, 0.1% were after 8 hours, and none detected after 10 hours. The inoculum source overwintered in the field released ascospores much more and earlier than the inoculum source kept in the greenhouse. The first ascospore release was about 10 days earlier, and the amount of the total liberated spores was 3∼4 times higher in the field inoculum source than the greenhouse nioculum source. The early defoliated leaves (in early October) in the previous year produced ascospores twice more than the late defoliated leaves (in early November) produced.

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Development and sustained release effect of implantable formula of somatotropin (Somatotropin 이식 제형 개발과 지속적 방출 효과)

  • Kim, Nam-Joong
    • Korean Journal of Veterinary Research
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    • v.48 no.1
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    • pp.27-32
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    • 2008
  • The present study was carried out to develop a sustained release implantable formula of bovine somatotropin (SRIF-BST) and to examine its sustained release effect. The SRIF-BST was produced by coating a solid pellet, which was comprised of BST and an excipient, made of a biodegradable polymer and poloxamer, which are capable of regulating the rate of BST release. The coated membrane of SRIFBST was observed with a field emission scanning electron microscope. The thickness of the coated membrane was approximately $1{\mu}m$, and the pore sizes of the coated membrane surface were below $10{\mu}m$. In dissolution test, the release duration of the SRIF-BST maintained for 10 days, whereas the release duration of the control BST formula maintained for 3 days. In weight gain assay and tibia test of hypophysectomized rats, the release duration of the SRIF-BST treated group was 12 days and the net weight gain was 53.16 g, also the tibia length and strength of the SRIF-BST treated group was increased 10.5% and 23.1% compared with those of the control group, respectively.

Estimation of Amounts of Water Release from Reservoirs Considering Customary Irrigation Water Management Practices in Paddy-Field Districts (관개지구의 관행 물관리를 고려한 저수지 용수공급량 추정)

  • Kang, Min Goo;Oh, Seung Tae;Kim, Jin Taek
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.5
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    • pp.1-9
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    • 2014
  • The DIROM (Daily Irrigation Reservoir Operation Model) was modified to estimate amounts of water release from reservoirs, considering customary irrigation water management practices, such as water supply for puddling and transplanting paddy rice from seeding beds and mid-season drainage. The applicability of the modified model was investigated by simulating amounts of water release from three study reservoirs: Hwamae, Ogi, and Doya Reservoirs. In terms of annual amounts of water release, the relative errors between the observed and simulated values in 2012 and 2013 ranged -26.20 % to 10.28 % and 4.90 % to 30.06 %, respectively; in case of reservoir water levels, the RMSE values ranged 0.45 m to 1.34 m and 0.40 m to 1.27 m, respectively. Also, it was revealed that the model provided better simulation results for monthly water releases than the original model. In addition, the model presented better performance in simulating 10-day amounts of water release from April to June. However, the model had still significant errors in the simulation results from July to September because the reservoirs were practically operated to adapt to water management circumstances. Finally, it is concluded that the modified DIROM can estimate the amounts of water release from reservoirs, reflecting irrigation water management customs in paddy-field districts. To achieve higher prediction accuracy of the model, it is necessary to incorporate practical reservoir operation rules into the model.

Slow Release Fertilizer Decreases Leaching Loss of Nitrogen in Sand-based Root Zone (완효성비료의 모래식재지반에 있어서 질소용탈의 감소)

  • Chen, Wei-Feng;Wei, Wang;Ying-Jie, Qi
    • Asian Journal of Turfgrass Science
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    • v.21 no.2
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    • pp.177-182
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    • 2007
  • When a football field is constructed using sand medium, the fertilizer management has to be adjusted because of the low nutrient holding capacity and higher leaching rate. The objective of this study was to test the effects of slow release fertilizers on Kentucky bluegrass (Poa pratensis L.) growth in simulated sport field rootzones with PVC pipe pots. Data of turfgrass color, uniformity, growth rate, biomass above ground, and the nitrate content in the leaching solution was collected at different growing stages and during four simulated rain fall periods. The result showed that the nutrient release rate of urea was the highest and that of controlled release nitrogen fertilizer was the lowest. Effects of the controlled release nitrogen fertilizer lasted 14 days more than other lawn fertilizers and 28 days longer than regular urea with acceptable quality levels of turf. The slow release fertilizer also restrained excessive growth of the grass, reduced the times of mowing. Slow release fertilizer used in this study reduced $NO_3$-N leaching by almost 50% at the beginning of turf establishment.

A Study on the Dynamic Stress Intensity Factor of Orthotropic Materials(II) A Study on the Stress Field, Displacement Field and Energy Release Rate in the Dynamic Mode III under Constant Crack Propagation Velocity (직교 이방성체의 동적 응력확대계수에 관한 연구 (II) 등속균열전파 속도하에서 동적모드 III 상태의 응력장, 변위장, 에너지해방률에 관한 연구)

  • 이광호;황재석;최선호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.2
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    • pp.331-341
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    • 1993
  • The propagating crack problems under dynamic antiplane mode in orthotropic material is studied in this paper. To analyze the dynamic fracture problems by theoretical method or experimental method in orthotropic material, it is important to know the dynamic stress intensity factor in the vicinity of crack tip. Therefore the dynamic stress field and dynamic displacement field with dynamic stress intensity factor of orthotropic material in mode III were derived. When the crack propagation speed approachs to zero, the dynamic stress components and dynamic displacement components derived in this paper are identical to the those of static state. In addition, the relationships between dynamic stress intensity factor and dynamic energy release rate are determined by using the concept of crack closure energy with the dynamic stresses and dynamic displacements derived in this paper. Finally, the characteristics of crack propagation are studied with the properties of orthotropic material and crack speed. The variation of angle .alpha. between fiber direction and crack propagating direction and crack propagation speed fairly effect on stress component and displacement component in crack tip. The influence of crack propagation speed on the speed on the stress and displacement is greater in the case of .alpha.=90.deg. than in the case of .alpha.=0.deg. and the faster the crack propagation speed, the greater the stress value and displacement value.

Biological Control of Two Spotted Spider Mite (Tetranychus urticae) by the Predatory Mite (Phytoseiulus persimilis) in Sustainable Strawberry Fields (친환경 딸기 재배 농가에서 칠레이리응애를 이용한 점박이응애 생물적 방제)

  • Kim, Do-Ik;Kim, Seon-Gon;Shin, GiI-Ho;Seo, Jong-Bun;Choi, Kyong-Ju;Lim, Kyeong-Ho;Kim, Sang-Soo
    • Korean Journal of Organic Agriculture
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    • v.14 no.3
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    • pp.315-323
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    • 2006
  • The potential of the predatory mite Phytoseiulus persimilis (Acarina : Phytoseiidae) to control two spotted spider mite Tetranychus urticae (Acarina : Tetranychidae) was investigated on sustainable strawberry fields in Jeonnam area. The density of T. urticae increased from 4th and 7th weeks after single and two timings release P. persimilis, respectively. On the three timings of release plot, number(density) of T. urticae on a leaf maintained fewer than 10 during the 15 weeks after release. In the 1,000 release of P. persimilis per $100m^2$ plot, P. persimilis could not suppress T. urticae. In the 2,000 release plot, P. persimilis could suppress T. urticae with low density which was the similar in the 3,000 release plot. Two-spotted spider mite, T. urticae, occurred from late March and increased density in Hampyeong area. In the P. persimilis released field, T. urticae inhibited continuously after release. In Boseong area, density of P. persimilis increased 50 per 10 leaves through increasing of T. urticae. Percent of occurrence of T. urticae showed high $10.5{\sim}75.5%$ in none-release predatory mite but not high in release treatment. T. urticae on sustainable strawberry field could be inhibited by P. persimilis.

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