• 한국작물학회지
• /
• 제64권3호
• /
• pp.213-224
• /
• 2019

There is an increasing frequency in the occurrence of abnormal weather phenomena such as sharp increases and decreases in temperature. Under these weather conditions, the heading time of rice changes unexpectedly, which poses problems in agriculture. Therefore, we investigated the effect of temperature on the heading response at different growth stages in rice. During the period from transplanting to heading, the plants were subjected to different temperature treatments, each for a 9-day period, to observe the heading response. For the heading date analysis, "heading date" was defined as the number of days from transplanting to the appearance of the first spikelet. We found that the influence of temperature increased in the order of rooting stage, followed by meiosis, early tillering, spikelet differentiation, and panicle initiation stage in all ecological types and cultivars. In particular, unlike the results reported previously, the effect of temperature on heading during the photo-sensitive period was very small. Meanwhile, the influence of temperature on vegetative growth response at different growth stages was not consistent with heading response. These results can be used as basic data for predicting the variation in heading date owing to temperature variation at each growth stage. In addition, we propose that the concept of day length should be included in determining the influence of temperature on the photo-sensitive period.

• 전기의세계
• /
• 제17권2호
• /
• pp.16-26
• /
• 1968

Cds is possible to add excess donors and to compensate partially using other group metals as acceptors. The impurities can ble incorporated either during crysta growth or by diffusion into a bulkcrystal. The addition of rimpurities leads also to the production of vacancies in a manner depending on the atmosphere surrounding the crystal during growth, during the diffusion process or using bulk. Cds of the mentioned above affects spectral sensitivity, speed of response, the variation on photocurrent, electron life time, and decay of photoconductivity with temperature and with intensity of illumination. In the work to be deseribed, these properties have been studied between liquid nitrogen and room temperature. In addition, the electron trap distribution has been correlated with speed of response, variation of photocurrent with temperature in various atmosphere. Four major trapping levels have been observed, and their identification with impurity and vacancy levels is discussed. And also the effects of lattice imperfections on the photoconductive properties CdS were investigated in detail.

• 한국작물학회지
• /
• 제47권4호
• /
• pp.301-304
• /
• 2002

The variation of alternative and cytochrome respiration during ripening in rice leaves (Oryza sativa L. cv. Takanari) was examined. The capacity of both respiration pathway was measured by inhibitor titration method using gas-phase oxygen electrodes. The alternative respiration rate decreased from 31.3% of the total respiration rate at around heading to 11.7% at 34 days after heading in the first fully expanded leaf from the top, and further to 6.4 % at 34 days after heading in the fourth leaf from the top. In contrast, the proportion of cytochrome respiration to total respiration increased with leaf senescence. The possible cause of alternative respiration as either an increase in inefficient respiration or a decrease in growth efficiency during ripening was discussed.

• 한국초지조사료학회지
• /
• 제16권4호
• /
• pp.291-298
• /
• 1996

This study was carried out at Crop Experiment Station in 1993 and 1994. The objective of this study was finding out variation of growth and yield of corn according to maturity. Hybrids of corn used in this study were early maturing corn Comet80, Elite90, Royaldent IOOT, Royaldent T$\times$llO, P3525, P3394, medium maturing corn Royaldent 120T. and late maturing corn Jungbuok, P3144W. G4743. Stalk height, leaf number, ear weight, stover weight, and TDN yield of early maturing corn were linearly increased with prolonged maturity in 1993 growing season. Leaf number, and stover weight of early and late maturing corn were linearly increased with prolonged maturity in 1994 growing season. But ear weight of late manuring corn was not increased as much as that of early manuring corn with prolonged maturity. Increase of total DM and TDN yield of late maturing corn was due to stover weight increase compared with ear weight increase of early maturing corn. Leaf number and stover weight were highly correlated with silk (Growing Degree Days) GDD.

• Water Engineering Research
• /
• 제5권2호
• /
• pp.81-99
• /
• 2004

Long term streamflow regime under virtual climate change scenario was examined. Rainfall forecast simulation of the Canadian Global Coupled Model (CGCM2) of the Canadian Climate Center for modeling and analysis for the IPCC SRES B2 scenario was used for analysis. The B2 scenario envisions slower population growth (10.4 billion by 2010) with a more rapidly evolving economy and more emphasis on environmental protection. The relatively large scale of GCM hinders the accurate computation of the important streamflow characteristics such as the peak flow rate and lag time, etc. The GCM rainfall with more than 100km scale was downscaled to 2km-scale using the space-time stochastic random cascade model. The HEC-HMS was used for distributed hydrologic model which can take the grid rainfall as input data. The result illustrates that the annual variation of the total runoff and the peak flow can be much greater than rainfall variation, which means actual impact of rainfall variation for the available water resources can be much greater than the extent of the rainfall variation.

• 소성∙가공
• /
• 제20권7호
• /
• pp.498-503
• /
• 2011

The strain rate sensitivity index, m, plays an important role in plastic deformation at elevated temperatures. It is affected by strain rate, temperature, and the microstructure of the material. The strain rate sensitivity index has been used as a constant in numerical analysis of plastic forming at a specified strain rate and temperature. However, the value of m varies as deformation proceeds at an elevated temperature and a certain strain rate. Thus, in this present study, the value of m has been characterized as a function of strain by multiple tensile jump tests for AZ31 magnesium alloy sheet, and the variation of m has been discussed in conjunction with the microstructural observations before and after deformation. The experimental results show that the variation of m is dependent on the temperature and strain rate. Grain growth with dynamic recrystallization also affects the variation of m.

• 한국자원식물학회지
• /
• 제19권6호
• /
• pp.677-679
• /
• 2006

The objectives of this study were to examine the genetic variation of 20-year-old tree height and to estimate heritabilities and genetic gains of Korean white pine. Analysis of variance showed that families and family x block interaction had the significant (p=0.01) effects on tree height. However, family variation appears to be much greater than the variation due to family x block interaction. Individual tree heritability was higher ($h_I^2=0.73$) than family heritability, ($h_F^2=0.83$) therefore, combined selection showed the largest genetic gain (17.76%) in a given equal intensity of selection.

• Clinical and Experimental Pediatrics
• /
• 제49권12호
• /
• pp.1263-1266
• /
• 2006

Nutrition is an essential component of total adolescent health care. Two important changes occurring during adolescence can cause a crisis in the teenager's nutritional needs. First, growth in height, weight, and body component is greater and more rapid than at any time since infancy. Second, an adolescent's eating habits may change from regular meals prepared at home to irregular meals, skipped meals, and nutrition-poor snacks and fast-food meals. Adolescents have been found to have the highest prevalence of any age group of an unsatisfactory nutritional status. To understand the nutritional requirements of the adolescent, health practitioners should be aware of the intensity and timing of the adolescent growth spurt, the differences in the growth spurt between males and females, and the individual variation in timing of the growth spurt from teenager to teenager.

• Journal of the korean society of oceanography
• /
• 제31권1호
• /
• pp.1-6
• /
• 1996

Salinity ecotypes in Ulva pertusa Kjellman were examined for the growth responses of the three isolates taken from different salinity regimes. All isolates showed a broad salinity tolerance, but growth patterns were correlated with the salinity regime of their original habitat. The germlings from Anin exhibited optimum growth at the native salinity of 32%. The germlings from Yongyon which had hypersaline habitats were tolerable to high salinity, i.e. growth rates peaked at 40%, whereas those from Samgando which had low salinities achieved maximum growth rate at 24\%. The germlings of inter-isolate cross demonstrated intermediate growth response between that of their respective parents. Our data also clearly indicated intraspecific differences among the three isolates, which was interpreted as development of different physiological ecotypes. We conclude that U. pertusa may consist of several ecotypes, each of which has some capacity for physiological adaptation to salinity variations.

• 한국결정학회:학술대회논문집
• /
• 한국결정학회 2000년도 정기총회 및 구정회교수 추모 춘계학술연구발표회
• /
• pp.32-32
• /
• 2000