• Current Research on Agriculture and Life Sciences
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• 제30권2호
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• pp.97-104
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• 2012

Over the last century, drainage systems have become an integral component of agriculture. Climate observations and experiments using General circulation models suggest an intensification of the hydrologic cycle due to climate change. This study presents hydrologic simulations assessing the potential impact of climate change on subsurface drainage in Daegu, Republic of Korea. Historical and Long Ashton Research Station weather generator perturbed future climate data from 15 general circulation models for a field in Daegu were ran into a water management simulation model, DRAINMOD. The trends and variability in rainfall and Soil Excess Water ($SEW_{30}$) were assessed from 1960 to 2100. Rainfall amount and intensity were predicted to increase in the future. The predicted annual subsurface drainage flow varied from -35 to 40 % of the baseline value while the $SEW_{30}$ varied from -50 to 100%. The expected increases in subsurface drainage outflow require that more attention be given to soil and water conservation practices.

• 펄프종이기술
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• 제46권6호
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• pp.8-15
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• 2014

The increase of wet web solid content in wet pressing will save drying energy greatly. We applied wood flours as spacers to increase the old corrugated container (OCC) solid contents in wet pressing. The mixed furnish of OCC and wood flours of 3-5% (wt/wt) increased bulk and drainage rate, and by increasing wet pressing pressure, its solid content started to be higher than 100% OCC furnish at more than 50% solid content level. Addition of cationic starch and drainage aid to the mixed furnish increased solid content further up to around 2%. Cationic starch addition compensated or exceeded the loss of tensile and compressive strength caused by the addition of wood flour, but drainage aid did not. Cationic starch also improved the stretch of the OCC, which could mitigate cracking at folding in boxboard.

• 한국유기농업학회지
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• 제21권4호
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• pp.501-522
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• 2013

This study has performed comparative analysis on benefit indicators in agricultural irrigation and drainage project cases between Korea and Japan. The irrigation and drainage project with publicity should do economic analysis of direct benefit factors as well as indirect benefit factors. However, traditional economic evaluations are used that benefit factors are lack of consistency and focused on direct benefits. Therefore, the purpose of this study was to develop indicators for the economic evaluation of irrigation and drainage projects. We conducted a case study between Korea and Japan. The resulting benefit factors was divided into direct factors and indirect factors. The direct benefit factors were increase in income, cost savings. The indirect benefit factors were protection of property due to flooding, agricultural promotion, aesthetic improvement. The implications of this study are that the indicators of economic analysis can be evaluated and easily applied. Moreover, these indicators could promote the feasibility of economic analysis.

• 펄프종이기술
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• 제41권2호
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• pp.13-19
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• 2009

In order to produce high quality paper at the lowest cost in high speed, typically various polyelectrolytes as retention aids were used. Retention systems such as single polymer system, dual polymer system, and microparticle system were used. The objective of this study was to analyze the changes of retention, drainage, formation and fracture toughness depending on types of retention system, molecular weight of C-PAM and dosage sequences of agents. When single polymer system was applied, retention was increased with poor formation and drainage. When common microparticle system(C-PAM/bentonite) was used, high molecular weight PAM gave high retention and fast drainage, but poor formation. When the microparticle system with reverse dosage sequence(bentonite/C-PAM) was used, low molecular weight PAM gave high retention, fast drainage and good formation. When various retention agents were applied, fracture toughness was increased than that of blank. When using high molecular weight PAM and consequently causing excessive flocculation, fracture toughness was decreased.

• 한국관개배수논문집
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• 제13권2호
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• pp.209-215
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• 2006

• 생물환경조절학회지
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• 제21권4호
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• pp.398-403
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• 2012

폐양액 발생을 최소화할 수 있는 배액제로형 수경재배기술 개발을 위하여 토마토 수경재배 시 배액제로 센서를 이용하여 배액을 제로화 또는 최소화하였을 때 표준배액량 처리와 비교하여 근권환경 변화와 토마토의 생육, 수량, 품질 등에 미치는 영향을 구명하였다. 처리별 주당 1일 공급량은 표준배액률 처리가 1.4, 배액제로 1처리가 0.9, 배액제로 2처리가 0.8L이었고, 배액률은 표준배액률 처리가 23.8, 배액제로 1처리가 8.6, 배액제로 2 처리가 3.7%이었다. 표준배액률 처리, 배액제로 1과, 2처리의 함수율과 배지 내 EC는 각각 64.5~88.0%와 $1.5{\sim}3.5dS{\cdot}m^{-1}$, 40.3~76.0%와 $2.5{\sim}4.0dS{\cdot}m^{-1}$, 그리고 56.3~69.0%, $2.7{\sim}3.7dS{\cdot}m^{-1}$이었다. 토마토 생육은 표준배액률 처리에 비해 배액제로 처리에서 엽장, 엽수, 경경은 차이가 없었으나, 초장과 엽폭이 작은 경향을 보였다. 토마토 수량은 표준배액률 처리에 비해 배액제로 처리에서 상품수량이 7.7~12% 적고 1과중이 작았으나, 당도는 반대로 높았고 상품과률은 차이가 없었다.

• 한국유기농업학회지
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• 제21권3호
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• pp.403-411
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• 2013

본 연구에서는 왕우렁이를 이용한 벼 친환경 재배시 왕우렁이에 피해가 되지 않으면서 중간낙수에 의하여 벼 생육을 촉진하는 것이 가능한지 검토하고자 수행하였다. 낙수기간에 따른 토양수분함량과 왕우렁이의 생존율을 온실에서 포트실험을 통하여 조사한 결과, 토양 수분함량은 낙수 후 6일에 39.1%, 9일에 31.9%, 12일에 26.8%, 15일에 21.8%로 감소되었고, 왕우렁이는 치패의 경우 낙수 처리 후 12일까지, 중패는 낙수 처리 후 9일까지 100%의 생존율을 보였고, 낙수 후 15일에는 치패는 93.3%, 중패는 83.3%의 생존율을 보였다. 잡초발생량은 상시담수구와 중간낙수구간에 차이가 없었으며, 중간낙수에 의하여 주당 수수가 증가하여 중간낙수구의 쌀 수량은 511kg/10a로 상시담수구의 쌀수량 445kg/10a보다 66kg/10a 증가한 결과를 보였다.

• 펄프종이기술
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• 제30권4호
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• pp.11-17
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• 1998

Reducing the effluent discharge from a paper mill is urgently needed due to tightening environmental regulations and economic reasons. For a paper mill to respond to system closure it is required to adopt the best practical retention system that enables the mill to improve fines retention and drainage. In this study, effects of various retention agents on fines retention, drainage and formation were examined using linerboard stock in the laboratory. Among the retention aids tested, high molecular weight cationic polyacrylamides showed good efficiency both in retention and drainage. On the other hand, high charge density, low molecular weight polymeric retention aids showed little improvement both in retention and drainage. The best retention system selected from the laboratory experiment was applied on a paper machine producing linerboard to evaluate its effect on papermaking system closure.

• 한국관개배수논문집
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• 제8권1호
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• pp.115-124
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• 2001

농업부문이 사회에 제공하는 다양한 긍정적 외부효과가 인정됨에 따라, 대부분의 농업생산기반시설은 국부를 증진시키는 사회간접자본으로 인식되고 있다. 과거에는 수리시설을 비롯한 기반시설이 단지 생산성 향상을 위한 사회적 투자로 간주되었으며 따라서 사업에 대한 경제성 분석 또한 직접적인 경제적 효과에 대한 편익비용분석에 국한되었다. 그러나 최근에는 농업 및 생산기반시설이 제공하는 비시장적 가치가 점차 인정됨에 따라 그러한 가치 또한 경제성분석에 포함될 수 있다

• 한국관개배수회지
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• 26호
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• pp.18-21
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• 2001

국제관개배수위원회(ICID) 제52차 집행위원회의 및 제1차 아시아 지역회의가 $\ulcorner$농업, 물, 환경$\lrcorner$을 주제로 2001년 9월 16일부터 21일까지 대한민국의 서울에서 개최되었다. 이번 서울대회에서는 세계43개국 8개 국제기구로부터 550명의 대표가 참가하여, 아시아 지역에 초점을 맞추어 관개배수, 관개시스템의 자동화, 수질 및 수자원 정책, 환경, 홍수조절, 폐수 재 이용 및 감