• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.79-82
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• 2012

Blossom-end rot is probably the most recognizable Ca deficiency that affects fruit production including pepper. We investigated the induction of blossom-end rot during the period of rapid vegetative growth and fruit setting, and the effect of Ca fertilization on the suppression of blossom-end rot in pepper plants grown in a plastic-film house. During the first fruit setting period, more than 60% of pepper fruits larger than 8 cm showed the symptoms of blossom-end rot. Under the condition of transpiration occurring at a much faster rate, growing leaves of pepper plants could be the greater sinks for Ca than developing fruits. The incidence of blossom-end rot was significantly decreased after two weeks of Ca fertigation. Calcium application during the rapid vegetative growth and fruit setting period could be suggested as a preventive step to overcome the local Ca deficiency inducing blossom-end rot of pepper fruits.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.366-371
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• 2011

The sea squirt Halocynthia roretzi is mainly cultured in Tongyeong, Southern coastal area of Korea. This study presents the physiological rates of respiration, excretion, feeding and assimilation efficiency of the sea squirt Halocynthia roretzi to analyze the SFG(scope for growth) and net growth efficiency, determined during 2007. Oxygen consumption and nitrogen excretion rates increased with a rise in temperature during the summer period whereas feeding rates decreased. The O:N ratio was high during winter(October to February). Assimilation efficiency showed an annual average of 75.4% during the experimental period, except during a period of elevated temperature in July to September(average $25^{\circ}C$). Net growth efficiency($K_2$) was 8.7 to 64.2% except for May to September, when temperature increased at the aquaculture farm. SFG was negative from May to September, reflecting high temperatures and low feeding rates during this period; its highest positive values occurred during winter.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.4
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• pp.193-197
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• 2018

The ratio of the period of a diffractive element to the input beam size is a critical parameter in a diffractive beam shaper. We measured and calculated the Fraunhofer diffraction patterns of a periodic hologram with an input beam size similar to the period of the hologram. The measured intensities show very complicated patterns and are strongly dependent upon the center position of the laser beam relative to the hologram. Using a diffraction formula for a periodic hologram, we calculated the diffracted light intensities and fit them to the measured ones. The measured and calculated intensities are in good agreement even when the beam diameter of the incident laser is similar to the period of the hologram. We can therefore use this formula to estimate the output of a periodic beam shaper even under such an extreme condition.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.1
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• pp.119-123
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• 2007

The objectives of this study were to characterize the changes occurring in the levels of insulin-like growth factors (IGF-I and IGF-II) in bovine milk during a one-year lactation period, and to determine the parameters affecting IGF content in bovine milk. Milk was collected individually from lactating Holstein cows (n=70), and IGF-I and -II levels were determined via radioimmunoassay, using 125I after acid-ethanol treatment. The proximate compositions of the milk samples were determined using a near-infrared milk analyzer. The data were analyzed by the GLM and CORR procedures using SAS software to determine significant differences (p<0.05) occurring within groups (dairy farms, lactation periods, season, and parity). We noted an approximately six-fold reduction in the IGF-I concentration (from 2,462.7 to 353.0 ng/ml) and a three-fold drop in the IGF-II concentration (from 929.1 to 365.7 ng/ml) in the bovine colostrum, between 6 h after parturition and 18 h after parturition. IGF-I and -II content, measured at the early, middle, and late stages of lactation did not change significantly throughout the entirety of the lactation period. Interestingly, parity did not significantly affect IGF-I content, but did significantly affect IGF-II content between the primiparous and multiparous cows. We also found there were no significant relationships between IGF-I and total protein content or somatic cell counts (p<0.05).

• The Plant Pathology Journal
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• v.18 no.2
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• pp.81-84
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• 2002

Effects of temperature and dew period on sporulation of a mycoherbicide, Epicoccosorus nematosporus, on the lesion of its host, Eleocharis kuroguwai were determined. Conidia formation was first observed after 10 days on plants incubated for either 12 or 16 h in a dew chamber at 28$^{\circ}C$; 16 h dew period resulted in more conidia formation. As the dew period was decreased to less than 8 h, fewer conidia formed. Conidial production was most abundant at 28$^{\circ}C$ and produced as much as 3.3$\times$10$^4$conidia per lesion, while 0.1$\times$10$^3$and 2.3$\times$10$^3$conidia per lesion were produced at 16$^{\circ}C$ and 36$^{\circ}C$, respectively. Alternating temperature regimes, i.e., 30/15, 30/20, 28/20, and 28/15$^{\circ}C$ (day/night) were much better than constant temperature, i.e., 30/30, 28/28/, and 20/2$0^{\circ}C$ for sporulation. In the second sporulation, there were as much as 3.1$\times$10$^4$conidia per lesion (ca. <50% of the first sporulation). Then, sporulation dropped sharply to 6.2$\times$10$^2$conidia per lesion in the third sporulation. Results of this study suggest that temperature combined with dew period is the primary limiting factor in the use of E. nematosporus as a mycoherbicide off, kuroguwai.

• Korean Journal of Microbiology
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• v.7 no.1
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• pp.1-9
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• 1969

Changes in the phosphorylation of Chlorella cells during the life cycle the aulotrophic and micotrophic synchronous culture were followed under the light and dark. 1. In the autotrophic culture of Chlorella the amounts of esterified phosphate compounds of the algal cell under the light increased during the growing period and decreased strikingly in the ripening period showing a peak at the $L_1$ i/-cell stage. 2. TRhe amount of total esterified phosphate compounds of the cell under the dark, however, decreased during the growing period and then kept fairly constnat during the ripening nad division periods showing the greates activity of the oxidative phosphorylation in the early growing stage. 3. It is presumed that the energy requirement of the dividing algal cell in the autotrophic culture is fulfilled prior to the nuclear division mostly by the photosynthetic phosphorylation. 4. In the mixotrophic culture, the amount of esterified phosphate compounds of the algal cells under the light increased during the growing period and decreased during the late ripening and early division periods showing a peak in the $L_2$-cell stage as in the case of the phosphorylation under the dark. 5. The phosphorylation of the fell grown in the glucose medium is more active under the dark than under the light in the stages of the growing and early ripening periods. 6. It is considered that the excess glucose in the algal cell not only promotes the oxidative phosphorylation but also inhibits the photosynthetic phosphorylation of the cell. 7. It is presumed that the energy requirement of the dividing algal cell in the glucose medium is fulfilled prior to the nuclear division by the combined action of oxidative and photosynthetic phosphorylation, mostly by the oxidative phosphorylation.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.257-262
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• 2021

The pinning method is the traditional method to produce strawberry transplants. But, cultivating the pinning transplant is a labor-intensive operation and needs a long labor period. The cutting method has been considered as an effective alternative to the pinning method, due to the relatively short labor period and works time. This study was conducted to investigate the labor period, work time, and growth between pinning and cutting methods for strawberry transplants. The 'Maehyang' strawberry was cultivated at each pinning and cutting strawberry greenhouses. The time for special works on pinning method (pinning work, elimination of mother plant, and division of daughter plant), and cutting method (cutting collection, pretreatment before storage, and cutting work) were measured. The pinning method needed 6 tasks (planting of mother plant, maintaining of mother plant, pinning work, maintaining of daughter plant, elimination of mother plant, and division of daughter plant) for 158 days, and cutting method needed 4 tasks (collection and storage of cutting, cutting work, misting, and maintaining of transplants) for 113 days to cultivate transplants for fruit. And pinning method needed more work time than the cutting method. There was no significant difference between the growth of pinning and cutting transplants. These results showed that the cutting method saved more labor period, work time than pinning during the nursery period without losing transplant quality.

• Journal for History of Mathematics
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• v.26 no.2_3
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• pp.177-195
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• 2013

This study is the analysis of the concepts and the characteristics of the mathematics section of the College Scholastic Ability Test. The study starts with division of the history of the College Scholastic Ability Test into four periods. These are Introduction Period(school year 1994-1996), Adjustment Period(school year 1997-2004), Development Period(school year 2005-2011) and Conversion Period(up to present since school year 2012). The periodical division of the Mathematics section is considered as identical with that of the College Scholastic Ability Test. So we investigate the characteristics of the Mathematics section through the periodical classification. This study also proposes some tasks for the future Mathematics section of the College Scholastic Ability Test.

• Journal of Navigation and Port Research
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• v.33 no.2
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• pp.105-110
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• 2009

Shipwaves am have harmful effects on ships working on the sea, in a harbour or navigational channel and caused beach erosion, seawall destruction. This study aims to investigate describe the characteristics of the wave pattern generated by an individual model ship tested at different velocities and hull forms for a given water depth and to investigate the variations at a given distance from the sailing line under the same conditions. As a result, the angles a's by model ship tests are smaller than those by real ship ones. Wave heights decreases with an increasing the mid-ship cross sectional area $A_s$. The maximum wave height and period increase rapidly in the subcritical speed, and beyond the critical speed the height and period decrease with increasing depth Froude number. And the period keeps constant with the distance from the sailing line.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.50-53
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• 2002

To develop Epicoccosorus nematosporus as a mycoherbicide of Eleocharis kuroguwai, the optimum temperature and humidity for sporulation of the pathogen were studied. Conidial production was most abundant at $28^{\circ}C$ with RH 60%, which yielded 661 mg in 9 cm Petri dish. Light intensity of 3,000 up to 7,500 lux was effective in stimulating conidial production of E. nematosporus on oatmeal agar, Light intensity affected sporulation more significantly than temperature. In the pot test, at least 12 h of dew period at $20^{\circ}C$ and $25^{\circ}C$ was required to achieve satisfactory conidial germination and appressorial formation. Few were killed at 8 h of dew period regardless of temperature. Sixteen hours of a single dew treatment immediately after inoculation killed more plants than did two or three repetitive dew treatments of 8-12 h.