• Journal of The Korean Society of Grassland and Forage Science
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• v.11 no.4
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• pp.209-214
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• 1991

The germination of seeds is developmentally complex process requiring water uptake, which is regulated by both genotypic and environmental factors. The present study was undertaken to determine the difference in germination characteristics, and to compare the ability of the logistic and Weibull functions to describe the cumulative germination curve when two levels of osmotic potential(0, -5 bar) were put to seeds of alfalfa, tall fescue, orchardgrass, and Kentucky bluegrass. The effects of grass type, osmotic potential, and their interaction on the total germination and coefficient of germination velocity were significant(P<0.01). The Weibull equation for predicting percent cumulative germination curve of alfalfa had significantly lower residuals than the logistic equation regardless of osmotic potential(P<0.01), indicating that the Weibull equation was more efficient than the logistic equation to fit the data of the percent cumulative germination of alfalfa. The rate parameter from the logistic equation was decreased under water stress, whereas the scale and shape parameters were increased. There were significant differences in days to 20% germination estimated from the logistic and Weibull equations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.228-234
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• 1993

Seedling emergence of 15 rice varieties (Gayabyeo, Chilseongbyeo, Samgangbyeo, Yeongsanbyeo, Yeongdeugbyeo, Hwajinbyeo, Palgongbyeo, Seomjinbyeo, Tamjinbyeo, Milyang 95, M 101, M 202, Newbonnet, Tebonnet, and Lemont) were tested at different soil moisture regimes and seeding depths. Submergence for four days immediately after seeding did not reduce emergence rate in all varieties. Under the flooded condition, the percentage of emergence of all varieties at 1.5cm seeding depth ranged 0～40%, it is much lower compared to uncovered control, and percentage of seedling survival ranged 0～24% due to death of some emerged seedlings. Under the field condition, one time flooding up to 10cm above the soil surface after seeding did not reduce the percent emergence of seedlings. The pF value of soil was 0 for few days after flooding or raining and Eh of soil ranged 443-453m V.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.145.2-146
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• 2003

일반 근채류와는 달리 기계적, 화학적 박피방법이 불가능한 도라지는 수작업에 의한 박피만이 가능하여 다양한 수작업에 의한 박피 처리후의 품질을 비교한 결과, 감모율에 있어 박피 도구를 사용한 수작업시 15.93%로 박피 도중 제거되는 측근의 수가 많아 높게 나타났다. 박피 처리후의 수분함량 변화는 칼을 이용한 수작업 처리구에서 초기치 88.26%에서 3시간후 71,55%로 16.71%의 감소율을 보였으며, 박피 도구를 사용한 수작업 처리구에서는 14.38%, sandpaper에 의한 수작업 처리구는 16%의 수분함량 감소율을 보였다. 한편, 우엉의 박피 감모율은 다른 품목과는 달리 칼을 이용한 수작업 박피에서 18.20%로 가장 크게 나타났으며, brushing에 의한 박피가 8.05%로 가장 적은 감모율을 나타내었다. 박피 처리후의 수분함량 변화는 박피 도구를 이용한 수작업 처리구가 80.50~71.30% 범위로,7$0^{\circ}C$, 12%-NaOH 에서 30초간 처리한 우엉의 80.56~69.54% 보다 다소 높게 유지되었다. pH 변화도 6.58~5.67 수준으로 다른 근채류와 마찬가지로 큰 변화가 없는 것으로 나타났다. 또한, brushing에 의한 방법은 박피 직후에 갈변도가 0.85로 다소 높게 나타났으나 시간이 경과함에 따라서는 갈변정도가 더디게 진행되는 특징을 보여 주었다.

• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.66-72
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• 2004

본 연구는 접지저감제의 성분으로 수용성 고분자의 유기물과 층상형 점토의 무기재료를 주재료하여 새롭게 개발한 새로운 형태의 접지저감제의 성능비교에 관한 것이다. 신개발의 접지저감제는 수분을 흡습하여 수분에 용해된 수용성고분자가 수분과 함께 층상형점토의 층으로 삽입되어 접지저감 성능을 발휘하게 된다. 본 연구의 유 무기 복합재료형 접지저감제는 함수율과 팽창률이 매우 우수할 뿐 아니라 300wt%의 수분을 공급 후 측정한 전기전도도도 매우 뛰어나다. 또한 환경친화적인 천연재료들이므로 인체나 환경에 매우 안전하며, 접지전극의 부식과 전식을 방지하는 기능이 매우 뛰어나 염해나 화학적으로 부식성이 높은 토양에서 큰 장점을 갖는다. 본 논문에서는 신개발의 접지저감제와 기존의 여러 접지저감의 성능을 비교 분석하였다. 이를 위해 현장의 대지저항율을 측정 분석하여 각각의 접지저감제의 접지설계에 적용하여 시뮬레이션하였으며, 시뮬레이션 결과와 현장에서 실제 시공한 측정 결과와 비교 분석하였다.

• Analytical Science and Technology
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• v.16 no.4
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• pp.277-282
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• 2003

The amount of water for the cultivation of citrus is different based on the growing period. The effect of water stress induces to enhance of sugar accumulation in citrus. The water content in the leaves of citrus can be a index for watering during cultivation. The purpose of this study is to determine the water content of citrus leaves non-destructively by using near infrared spectroscopy (NIRS). Citrus leaves were prepared from 'Okitsu' Satusuma mandarin leaves (Citrus unshiu Marc.) ranging from 20.80 to 69.98% of water content by loss on drying method, and NIR reflectance spectra of citrus leaves were acquired by using a fiber optic probe. It was found that the variation of absorbance band 1450 nm from OH vibration of water depending on the water content change. Partial least squares regression (PLSR) was applied to develop a calibration model over the spectral range 1100-1700 nm. The calibration model predicted the water content for the validation set with a standard errors of prediction (SEP) of 0.97%. In order to validate the developed calibration model, routine analyses were performed using independently prepared citrus leaves. The NIR routine analyses showed good results with those of loss on drying method with a SEP of 0.81%. The rapid and non-destructive determination of the water content in citrus leaves was successfully performed by portable NIR system.

• Korean Journal of Plant Resources
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• v.14 no.2
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• pp.163-168
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• 2001

This study was conducted to obtain basic information on cross breeding for developing bolting resistant variety of Angelica gigas NAKAI which has been subjected to severe yield reduction resulted from flower-stalk initiation during the growth. Compatibility of selfing and/or crossing pollination among 5 local cultivars were tested. Results obtained are summarized as follows. In case of three year old plant, all cultivars emerged March 14 and bolted from May 12 to May 13. Ponghwa cultivar was flowered 3 to 5 days earlier than other cultivars. Flower duration continued 41 to 43 days. Interval of flowering date from main stem to first primary branch, from first to second or second to third primary branch was 9 to 13 days. Emergency of stamen proceeded 4~8 days of pistil initiation demonstrating that Angelica gigas NAKAI is protandrous plant. Furthermore initiation of first pistil was 1~4days later than formation of last stamen in the same flower cluster. Percent pollination of Angelica gigas NAKAI was 52% under natural condition, so called open-pollination, but bagging by enveloping flowers was as low as 0.4~2.4%. In the result of compatibility test, all local cultivars tend to show both of self-and cross-compatibility. Inpollination, ‘Muju’$\times$‘Muju’combination showed highest fertility up to 40.8% whereases cross pollination, ‘Pyeongchang’$\times$‘Inje’combination, showed 67.0% fertility.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.61-66
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• 2002

Double cropping system in a year in Kyoho grapes (Vitis labruscana L.) has currently been attempted in the plastic greenhouse. One of the problems in double cropping system is the promotion of bud break in summer season and shoot fertility. Effects of the control of soil moisture tension near the root zone and treatments of bud dormancy breaking agents on bud breaking in summer were examined to promote the bud break for the second fruiting. The lignification of shoots was induced in July or August by the control of soil moisture tension in root zone environment. The first shoot growth was almost the same as that in common plastic greenhouses. The highest bud break value appeared in the plot of cyanamide chemicals mixed with merit blue as over 75% bud break rate. The bud break rate in the discontinuing plot in irrigation showed significantly higher in bud break than that in the continuing plot in irrigation. Despite of the final high bud break rate, the time of bud break was irregular.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.7-10
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• 1993

Mulberry grafting season in normally a one month period starting at the end of March. Such a short period creates a shortage of qualified grafters and inflates wages. Pine tree sawdust was tested as a medium in which to preserve graftages. Sawdust was moistened to two ratios of water to dry weight of sawdust (1.5 and 2.0). Scions were either grafted the same day they were collected or first incubated for 10days at 15$^{\circ}C$. Grafting period could be extended to the middle of February under 1.5 times moisture content and fresh scions. Preservation of scions increased water content, T-N, P2O5, CaO and inositol, whereas decreased total C, glucose and fructose. With no preservation total C decreased, inositol increased slightly early March followed sharp decrease, and sucrose increased with time.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.138-138
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• 2010

플렉서블 디스플레이에 사용되고 있는 기판은 광학적 투과율이 우수하고 휘어지는 폴리머 기판이 많이 활용되고 있으나 대기중의 수분 및 산소와 같은 가스성분들이 기판을 통해 침투하여 디스플레이의 수명을 감소시킨다. 이러한 문제점을 해결하기 위해 투명하면서 절연특성이 뛰어나고 수분투과 방지 특성이 뛰어난 실리콘 화합물을 기반으로 하는 가스차단막의 연구가 활발히 진행되고 있다. 본 실험에서는 기존의 스퍼터링 장치에 비해 저온공정이면서 구조적으로 뛰어난 박막특성을 얻을 수 있는 대향타겟식 스퍼터링(Facing Targets System, FTS)법을 이용하여 PEN기판 위에 $SiO_x$, $SiO_xN_y$, $(SiO_2)_x(ZnO)_{100-x}$ (SZO)를 단일층또는 다층으로 증착한 박막들의 광학적, 구조적 및 수분 투과 방지 특성들을 알아보았다. $SiO_x$, $SiO_xN_y$, SZO박막들의 광학적 특성을 알아보기 위해 Shimadzu사의 UV-VIS spectrophotometer 장비를 사용하여 측정한 결과 가시광 영역에서 80%이상의 높은 광투과율을 나타내었다. 박막의 수분투과 방지 특성으로 Mocon사의 Permatran W3/31 system을 이용한 투습율을 측정결과 가스 차단막이 없는 Bare PEN에 비해 PEN기판 위에 $SiO_x$와 $SiO_xN_y$ 박막들을 단층 또는 다층으로 증착한 박막의 투습율이 감소한 것을 확인 할 수 있었다. 특히 SZO 박막의 경우 다른 가스차단막들과 비교해 가장 낮은 수분투과율을 나타내었다. 이는 향후 SZO를 기반으로 한 단층박막이나 무기/무기 또는 유기/무기의 다층 박막 형태를 가지는 가스차단막이 플렉서블 디스플레이에 적용 가능할 것이라 사료된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.142-147
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• 2020

This study investigates the effects of moisture content on diffuse ultrasound to be applied for the evaluation of micro-structural damage in concrete subjected to various environmental conditions. We monitored diffuse wave parameters for concrete samples in process of water saturation for 5 days. Dried samples were immersed in a water bath, and the change of moisture content in concrete were estimated by measuring the change of mass. For the diffuse wave analysis, a frequency range of 500 kHz, which represents a scattering regime of ultrasound in concrete, was selected. The test results reveal that the ultrasonic diffusivity slightly changed, and the ultrasonic dissipation significantly increased by approximately 120% in the process of water saturation. Therefore, the moisture content in concrete should be considered for the evaluation of micro-structural damage using diffuse wave techniques.