• 한국작물학회지
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• 제32권1호
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• pp.103-111
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• 1987

Understanding grain filling characteristics represented by grain filling duration and grain filling rate is import-ant in improving higher yielding varieties and developing better cultural methods of rice (Oryza sativa L.). Recently developed 6 Japonica and 6 Japonica/Indica varieties were grown under 3 nitrogen levels at Experimental Farm of Chungbuk National University in 1986. The range of grain filling duration of 12 varieties was 20.9-39.0 days, while grain filling rate ranged from 53.8 to 136.6 mg. panicle$^{-1}$. day$^{-1}$. Although the difference of the average grain filling duration between Japonica varieties and Japonica/Indica was less than 4 days, the average grain filling rate of Japonica/lndica varieties was greater than Japonica more than 30%. Samgangbyeo showed the shortest grain filling duration of 21.0-24.2 days and the greatest grain filling rate of 119.3-143.8 mgㆍpanicle$^{-1}$. day$^{-1}$ under 3 nitrogen levels, while Seomjinbyeo and Milyang 23 showed the quite opposite grain filling characteristics. Nitrogen levels did not show any significant effects on grain filling characteristics. Negative correlation was round between grain filling duration and grain filling rate, and significant positive correlations of grain filling rate with grains/panicle, grain weight and panicle weight indicated that grain filling rate is more important characteristics of grain filling. Pathway analysis revealed that contribution of grain filling rate to panicle weight is rather indirect through grain weight.

• 한국작물학회지
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• 제52권1호
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• pp.112-121
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• 2007

Grain filling is a crucial factor that determines grain yield in crops since it is the final process directly associated with crops' yield performance. Grain filling process can be characterized by the interaction of rate and duration of grain filling. This study was conducted, using 16 temperate japonica rice genotypes, with aims to (1) seek variations in grain filling duration and rate on area basis, (2) compare the contribution of grain filling duration and rate to grain yield, and (3) examine the influence of temperature and solar radiation for effective grain filling on grain yield in relation to grain filling duration and rate. Grain filling rate and duration exhibited highly significant variations in the ranges of $20.7{\sim}46.3\;g\;m^{-2}d^{-1}\;and\;11.2{\sim}35.5$ days, respectively, depending on rice genotypes. Grain yield on unit area basis was associated positively with grain filling duration but negatively with grain filling rate. Grain filling rate and duration were negatively correlated with each other. Final grain weight increased linearly with the rise in both cumulative mean temperature and cumulative solar radiation for effective grain filling. Higher cumulative mean temperature and cumulative solar radiation for effective grain filling were the results of longer grain filling duration, but not necessarily higher daily mean temperature and daily solar radiation for effective grain filling. Grain filling rate demonstrated an increasing tendency with the rise in daily mean temperature for effective grain filling but their relationship was not obviously clear. It was concluded that grain filling duration, which influenced cumulative mean temperature and cumulative solar radiation for effective grain filling, was the main factor that determined grain yield on unit area basis in temperate Japonica rice.

• 대한치과의사협회지
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• 제55권5호
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• pp.339-350
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• 2017

The aim of the study was to analyze the distribution of dental filling materials for carious permanent teeth of school children in a city. The study was designed as time-serial study, using the data of the dental survey for children aged 8-, 10- and 12-year children living in Gimhae city. The samples were selected by stratified clusters sampling. The number of surveyed samples in depth-analysis for types of dental filling materials were 567 in 2009 and 331 in 2013, respectively. They had dental restorations on one or more teeth. The changing pattern of used dental filling materials was analyzed between 2009 and 2013. Statistical analysis was conducted according to variables related to dental filling material type; DMFT and DMFS index, number of fissure sealed teeth and surface and surveyed year. Amalgam filling rate decreased from 27.9% in 2009 to 18.8% in 2013, while filling rate of tooth-colored materials increased from 56.1% in 2009 and 68.9% in 2013. Amalgam filling rate was a negative correlation with filling rate of tooth-colored materials or gold and number of fissure sealed teeth and a positive correlation with DMFT index. Filling rate of tooth-colored materials was a negative correlation with filling rate of amalgam or gold and DMFT index and a positive correlation with number of fissure sealed teeth. The light-curing composite resin should be included in the reimbursement range of National Health Insurance to solve an inequity of dental health care services.

• 소성∙가공
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• 제13권7호
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• pp.580-585
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• 2004

Almost all injection molds have multi-cavity runner system fur productivity and are designed with geometrically balanced runner system in order to minimize filling imbalance between cavity to cavity during processing. However, filling imbalances have been observed though geometrically balanced runner lay-out. Generally, these filling imbalances are due to thermal unbalance, viscosity, characteristic of polymers and so on. These kinds of filling imbalances have already been reported by Beaumont since 1997, but his research has mainly focused on filling imbalance at binary runner. In this study, we conducted an experimental study about the filling imbalances in unary branch runner as well as binary branch runner and inquired into the causes of filling imbalances. The results could be summarized as fellowing: Filling imbalances existed in multi-cavity mold with unary branch runner, it could be decreased by optimizing processing condition such as increasing injection rate, and it is almost proportion to each polymer's temperature sensibility.

• 한국작물학회지
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• 제36권2호
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• pp.166-173
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• 1991

출수후 등숙기간 동안에 엽신의 노화속도와 동화산물의 전류특성과의 관계를 구명하며 등숙향상 및 단기등숙 품종육성을 위한 선발지표를 제공코자 엽신의 노화정도가 다른 올보리외 29품종 및 계통을 공시하여 엽신 노화율, 등숙율 및 상호 상관관계를 조사하였던 바 결과를 요약하면 다음과 같다. 1. 엽신의 노화속도 및 입충전속도(등숙율)는 계통에 따라 큰 차이가 있었다 2. 등숙초ㆍ중기(출수후 10-20일) 및 등숙중ㆍ후기(출수후 20-30일)의 엽신 노화율과 해당 각 시기의 등숙율과는 높은 정의 상관관계가 있었다. 3. 등숙초ㆍ중기의 엽신 노화율과 등숙전기간(출수후 10-35일)의 등숙율과는 부의 상관이 등숙중ㆍ후기의 엽신 노화율과는 고도의 정의 상관관계가 있었다. 4. 입중과 등숙중ㆍ후기 및 등숙전기간의 등숙율과는 고도의 정의 상관관계가 있었으나 등숙초ㆍ중기의 등숙율 및 등숙일수와는 상관이 없었다. 5. 노화지수의 감소 양상은 계통에 따라 4가지 유형으로 분류할 수 있었는데 종실수량 및 등숙율면에서 가장 이상적인 유형은 IV형이었다 6. 본 시험결과 단기등숙형 대맥 품종으로 가장 이상적인 형은 등숙초ㆍ중기에는 노화지수가 높으면서도 노화속도가 느리나 등숙중ㆍ후기에는 노화속도가 빠른 품종임이 구명되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.706-709
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• 2005

Despite geometrical balanced runner system, filling imbalances between cavity to cavity have always been observed in multi-cavity injection mold. These filling imbalances are results from non-symmetrical shear rate distribution within melt as it flows through the runner system. It has been possible to decrease filling imbalance by optimizing processing conditions, but it has not completely eliminated this phenomenon during the injection molding processing. This paper presents a solution of these filling imbalances by using runner core pin which creates a symmetrical shear distribution within runner and the effects on filling imbalance when modifying a shape of runner core pin. As a result of using runner core pin, a remarkable improvement in reducing filling imbalance was confirmed. In addition we investigated how filling imbalances were affected by shape of runner core pin.

• 한국정밀공학회지
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• 제25권10호
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• pp.144-149
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• 2008

Configuration of filling imbalance which is originated from imbalanced share rate of melt on runner is changed by runner layout, runner shape, material property, injection pressure, injection speed, melt temperature and mold temperature. In this paper, we conducted a study of runner layout and shape that are main factors of filling imbalance. Other factors such as the sharp corner effect and the groove corner effect are recently released were also considered. The results of study are showed that filling rate of between inside and outside cavity was influenced on shape of runner. Especially, this study suggests a new runner system for filling balance by adapting the two effects of unary branch type runner at multi cavity mold and theoretical investigated flow in the sharp corner type runner.

• 소성∙가공
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• 제15권1호
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• pp.42-46
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• 2006

For mass production, usually injection mold has multi-cavity which is filled through geometrical balanced runner system. Despite geometrical balanced runner system, filling imbalances between cavity to cavity have always been observed. These filling imbalances are one of the most significant factors to affect quality of plastic parts. Filling imbalances are results from non-symmetrical shear rate distribution within melt when it flows through tile runner system. It has been possible to decrease filling imbalance by optimizing processing conditions, but it has not completely eliminated this phenomenon during injection molding processing. This paper presents a solution for these filling imbalances by using Runner Core pin (RC pin). The Runner Core pin which is developed in this study creates a symmetrical shear distribution within runner. As a result of using Runner Core pin, a remarkable improvement in reducing filling imbalances was confirmed.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.39-42
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• 2005

For mass production, usually injection mold has multi-cavity which is filled through geometrical balanced runner system. Despite geometrical balanced runner system, filling imbalances between cavity to cavity have always been observed. These filling imbalances are one of the most significant factors to affect quality of plastic parts when molding plastic parts in multi-cavity injection mold. Filling imbalances are results from non-symmetrical shear rate distribution within melt as it flows through the runner system. It has been possible to decrease filling imbalance by optimizing processing conditions, but it has not completely eliminated this phenomenon during injection molding processing. This paper presents a solution of these filling imbalances through using 'runner core pin'. The runner core pin which is developed in this study creates a symmetrical shear distribution within runner. As a result of using runner core pin, a remarkable improvement in reducing filling imbalance was confirmed.

• 한국작물학회지
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• 제33권1호
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• pp.5-11
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• 1988

Varietal differences of grain filling duration and rate are generally recognized in rice (Oryza sativa L.). But the differences of grain filling characteristics between the parts within a panicle might be present since it takes 6-8 days to finish anthesis in a panicle. To elucidate this, 6 Japonica and 6 Japonica/Indica varieties were grown under three nitrogen levels at the Experimental Farm of Chungbuk National University in 1986, and grain filling characteristics of top, middle and bottom parts of a panicle were analyzed. Rice grain filling duration could be divided into 3 phases, i.e., Lag phase(LP) of 5 days after heading. Linear increasing period (LIP) of 5-20 days after heading and Late filling period (LFP) thereafter. Grain weight difference between the panicle parts was greater during LIP in all the varieties and was decreased during LFP. The difference was greater in Japonica/Indica varieties. Samgangbyeo and Seomjinbyeo had the shortest and the longest grain filling durations with 22.6 and 37.1 days, respectively. In average, grain filling duration of the bottom part of a panicle was 1-2 days shorter than that of top or middle part. The differences were negligible in Daecheongbyeo, Taebaegbyeo and Milyang 23, while it was greater in Tongil with 4.9 days. Grain filling rates were ranged from 0.612 to 1.097 mgㆍgrain$^{-1}$ㆍday$^{-1}$ㆍMilyang 23 showed the lowest rate with 0.612-0.682 mgㆍgrain$^{-1}$ㆍday$^{-1}$, while the rates of Baegyangbyeo, Yongmoonbyeo, Samgangbyeo, Nongbaeg and Daeseongbyeo were about 1 mgㆍgrain$^{-1}$ㆍday$^{-1}$ㆍGrain filling rate of bottom part of a panicle was lower than that of top or middle part. The difference was samll in Nongbaeg and Daeseongbyeo, while it was the greatest in Tongil with 0.222 mgㆍgrain$^{-1}$ㆍday$^{-1}$. Grain filling duration and rate were not afftected by nitrogen level, but varietal and spatial differences of grain filling characteristics were highly significant. However, the spatial difference of grain filling rates within a variety was not significant. Grain filling characteristics of each part of a panicle were significantly correlated (r=0.7207-0.9879) with those of a whole panicle.