• 농업기술회보
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• v.49 no.5
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• pp.32-33
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• 2012

국내 시설원예 재배면적은 1980년대 이후로 급격히 증가했고, 시설채소 재배면적의 99%는 비닐하우스가 차지한다. 이러한 비닐하우스 재배로 채소로 사계절 생산이 가능해졌고, 국민들은 하우스에서 생산된 채소를 어느 때나 구입할 수 있게 되었다. 이러한 시설채소 재배에 피복되는 연질 필름의 소재는 폴리에틸렌(PE) 필름, 에틸렌아세트산비닐(EVA) 필름, 폴리올레핀(PO) 필름 등으로 나누어지고, 이러한 열가성수지에 각종 첨가제를 추가해 보온성, 유적성, 내후성을 향상시킨다. 최근에는 연동하우스와 하우스 피복비용의 증가로 인해 내구성 있는 장기사용 필름에 관한 관심이 높아지고 있다.

• Journal of the KSME
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• v.16 no.2
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• pp.6-14
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• 1976

원자로의 안전성확보의 기본은 원자로의 운전에 의한여 발새하는 방사성 물질을 확실하게 관리하 여 방사서의 해로부터 공중의 건강과 안전을 보존하는 것이다. 원자로에는 로내의 방사성물질인 핵분열생성물의 누설을 방지하는 일련의 독립적 방벽들 즉 연료의 피복제, 원자로용기를 포함하 는 일차냉각재계용, 그리고 일차냉각재계통을 수용하는 격납용기들로 된 다중방호벽이 마련되어 있다. 원자로설계기준에서는 이들 방호벽이 어떠한 가상적사고가 발생하여도 그 건전성이 유지되 도록 요구하고 있디. 우리나라에서도 미국의 기준을 준용하는 원칙으로 고리 원자력발전소 등 1 호기에 대한 해석이 수행되었던 것이다. 여기서 해석판정기준 및 해석결과를 소개하고저 하는 것이다.

• Magazine of the Korea Concrete Institute
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• v.2 no.4
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• pp.61-68
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• 1990

This experimental study is aimed to investigate the coating method of scoria lightweight aggregate for reo duction of water absorption and the physical dynamic characteristics of coated-scoria jightweight aggregate con¬crete. The coating methods are as follows: I) Non-coating method. II) Coating method of only cement paste. rn) Coating mehtod of surface-coating agent after coating by cement paste. IV) Coating method of only surfaee-coating agent. V) Coating method of cement pasted after coating by surface-coating agent. The summerized conclusion are as fallows ; 1) Specific gravity and the rate of water absorption were lowest when aggregate was covered by only surface-coating agent, especially, rate of absorption was about 10% of non-coating aggregate. 2) Coated-aggregate were about 0.87~0.97t/m3 and lightweight concrete made of coated-aggre¬gates were 1.80~ 1.94 t/m3 in unit weight. 3) Compressive strength of the lightweight concrete made of cement pasted-coating aggregate was about 200~215kg/crrl. 4) The higher the rate of water absorption of coarse aggregate, the higher the rate of deterioration of compressive strength.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.236-241
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• 2013

Introduction of rye living mulch in soybean production is important for labor-saving and reduction of herbicide usage for weeding by weed suppression and for soil conservation by mulching of rye. Soybean and rye were row-planted and broadcasted simultaneously at different planting times (May 15, May 25, June 5) and row widths (35 and 70 cm) in 2010, different soybean cultivars (Daepoong, Singi) and planting times (May 15 and June 1) in 2011, respectively, and investigated weed occurrence, early growth and yield of soybean. Acalypha australis, which is known to herbicide-resistant weed, could be controlled ecologically by rye living mulch. Occurrence of Acalypha australis was controlled effectively also by mixture of alachlor and linulon at no mulch in 2011. Early growth amount of soybean plant per area was increased by narrow row width (35 cm) at rye living mulch, which was helpful in the control of weeds, but grain yield of soybean with narrow row was decreased compared to conventional row width (70 cm) at the planting in early June. It is concluded that soybean planting as row width 70 cm in early June is proper at simultaneous planting with rye.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.191-196
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• 1998

This experiment was conducted to investigate the mulch effect of rice straw and dead water foxtail treated with herbicides on weed germination, seedling establishment, and early growth of rice under the no-till culture condition. The percent seedling establishment of rice straw + dead water foxtail mulch was decreased significantly compared to rice straw mulch and non-mulch. Rice straw mulch and rice straw + dead water foxtail mulch inhibited the early growth of no-till direct seeded rice remarkably. However, they promoted rice growth after active tillering stage. Rice straw mulch and rice straw+dead water foxtail mulch in no-till direct seeding decreased weed occurrence significantly. The control value of barnyardgrass, compared with non-mulch, was 96.5% in the rice straw mulch and 75.6% in the rice straw + dead water foxtail mulch, respectively. The pH and concentration of dissolved oxygen in irrigated water were reduced significantly by both rice straw mulch and rice straw+dead water foxtail mulch during early rice growth stage.

• Nuclear Engineering and Technology
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• v.18 no.3
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• pp.218-227
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• 1986

Studies were conducted to determine the extent of oxidation and same of the mechanical property changes of Zircaloy-4 fuel cladding after it was exposed to hot steam environment. The purpose of these tests was to provide some informations on the embrittlement behavior of CANDU type fuel cladding, which could be experienced under the loss-of-coolant accident conditions. The Zircaloy fuel cladding tubes were exposed in a steam environment at the temperature of 90$0^{\circ}C$, 1,00$0^{\circ}C$. The growth of the ZrO$_2$ layer combined with an oxygen rich $\alpha$-phase layer into the Zircaloy tube material was found as a function of time t and temperature of steam exposure, E=1.1√Dt+0.002 where D is a temperature dependent diffusion coefficient. The tensile strength of the specimens exposed for a short period increased but decreased continuously with further exposure. The circumferential elongation was drastically changed with the exposure time while the hoop strength did't decrease greatly. The X-ray measurement of preferred orientation of the Zircaloy tube material indicated that grains in the as received tube were oriented such that the poles of the basal (0001) planes were predominantly radial, while the poles of the basal plane in the tube materials heattreated at 1,00$0^{\circ}C$ were oriented tangentially. It appears that this reoriented texture may contribute to lessening the decrease of the hoop strength of the heat treated Zircaloy tube material.

• Journal of Bio-Environment Control
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• v.10 no.3
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• pp.181-186
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• 2001

During the growth of fruit vegetables such as pepper, cucumber and tomato, there are light deficiency under the plant canopy. This study was conducted to clarify the effect of light diffusion film on the stem growth, canopy, flowering and fruiting of green pepper in greenhouse. The transmittance of total solar radiation into greenhouse under woven and double films were 90% and 75% of polyethylene film. And the transmittance of photosynthetically active radiation into greenhouse under woven and double films were 96% and 81% of polyethylene film. However, the light diffusions under woven, double and polyethylene films were 46%, 31% and 9%, respectively. The plant height under polyethylene film covered greenhouse was 96.9% cm, taller than those under woven and double films by 6.5, 13.9 cm. And the third node length under woven film covered greenhouse was 8.6 cm, shorter than those under double and polyethylene films by 2.5, 5.7 cm. Also the first branch angle under woven film covered greenhouse was 61.0$^{\circ}$, larger than those under double and polyethylene films by 2.3, 10.3$^{\circ}$. But there was no clear difference in the node numbers among the covering materials. The rate of curved and sterile fruit under woven film covered greenhouse was smaller than those under double and polyethylene films by 4.6, 5.5% and 1.2, 3.6%. But the contents of vitamin C showed no difference among the covering materials and plant densities.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.93-97
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• 1997

$CO_2$ gas를 초임계상태의 유체로하고 그 용매에 코팅물질인 파라핀을 용해시켜 초임계 분출법(RESS)에 의해 핵입자 코팅을하여 복합입자를 제조하였고 그 용출 특성을 고찰하였다. 핵입자로는 입도분포가 다른 Glassb eads, Brilliant Blue(이하 BB)를 피복한 Glass beads, 분무건조법으로 제조한 염기성 탄산마그네시아의 Microcapsule(이하 MHC MC)을 사용하였다. 제조된 복합분체 표면을 SEM으로 관찰하였고 FT-IR을 사용하여 표면의 성분분석을 하였다. BB로 피복시킨 Glass beads는 Spectrophotometer로 BB가 용출되는 시간을 측정하였고 AA로 MHC MC중 Mg2+ ion의 release time이 7min, 26min, 30min으로 반응부에서 포집한 시료의 용출특성이 제일 우수하였다.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2002.04a
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• pp.13-19
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• 2002

우리나라에서는 결구상추보다 잎상추가 주로 재배되고 있고 특히 잎상추는 내한성이 강하여 $0^{\circ}C$에서도 잘 견디고 5$^{\circ}C$ 이상이면 겨울 저온기에도 무난방 재배가 가능하나 피복자재와 피복 노력 등의 비용이 많이 들고, 또 온도 환경이 불량하여 단경기 생산이 불가능하게 되어 주년 재배가 어렵게 되므로 저온기에 효과적인 보온 방법과 생장조절제처리로 엽채류의 생육 촉진 및 품질을 향상시킬 수 있는 방법이 필히 구명되어야 할 과제라고 생각된다. (중략)

• Korean Journal of Materials Research
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• v.13 no.9
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• pp.555-560
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• 2003

Ag-coated Cu particles were prepared by dropping method of coating agent and were evaluated by scanning electron microscope and color difference meter. The shape of Cu particles having obvious crystal plan and edge was changed spherically according to the increase of Ag coating amount. When the Ag coating amount was 50 wt% to Cu particles, the whiteness of Ag-coated Cu particles was almost similar to that of pure Ag particles. Adding $NH_4$OH in reductant solution could increase effectively the whiteness of the Ag-coated particles. The Ag-coated particles having the highest whiteness was obtained when the content of hydrazine in reductant solution was 0.48 M.