• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.343-349
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• 1988

In order to get informations for breeding early barley cultivars, the thermosensitivity and low temperature growth ability about the breeding materials vernalized were tested at the high '||'&'||'amp; low temperature and field conditions. The temperature coefficient (Q10), ratio and thermosensitivity for plant height were various among cultivars versus temperature treatments. The early cultivars had greater Q10 values and insensitive responses to temperature changes. The Q10 and thermosensitivity for the time of flag leaf unfolding were various among cultivars, but the coefficient of variation in the thermosensitivity was greater, so the character would be more useful for investigating the varietal differences. The Q10 and thermosensitivity for plant height were not significantly correlated with Q10 and thermosensitivity for the time of flag leaf unfolding. The periods from heading to flowering were 2 to 4 days at the high temperature plot, but 1 to 11 days at the low temperature plot, showing much greater variations. In general the cultivars with greater difference of heading time between the high and low temperature plots were Suwon 218, SB 76588, Oweolbori, and Jogangbori, showing the sensitive thermophase and early heading.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.11a
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• pp.31-31
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• 2011

섬유제품은 대부분은 흡수성 또는 흡유성을 가지고 있어 물이나 기름이 등을 쉽게 흡수하는 성질이 있다. 이러한 성질 때문에 물이나 기름 등의 접촉에 의한 얼룩과 오염이 잘 되는 단점을 가지고 있다. 이러한 문제점을 해소하기 위하여 원단에 대한 발수, 발유, 방오가공 등이 연구되어 왔으며 섬유의 고유한 화학적, 기계적 물성을 유지하면서 표면과 이면이 다른 특성을 가지도록 유도하여 기능성을 부여하는 편면가공을 주목을 받게 되었다. 본 연구에서는 불소계로 발수처리 된 PET직물에 저온 Plasma와 Sputter을 이용하여 직물의 한쪽 면에는 친수성과 다른 면에는 발수성이 동시에 나타나는 편발수에 관한 실험을 했다. 불소계로 발수처리 된 시료와 저온 Plasma처리된 시료와 Sputter처리된 시료(처리면, 미처리면)를 접촉각 5회 측정하여 평균값을 나타냈다. 발수처리 된 시료의 평균 접촉각 값은 $149^{\circ}$이며, 저온 Plasma의 평균값은 $45^{\circ}$(처리면) $128^{\circ}$(미처리면), Sputter는 $74^{\circ}$(처리면) $144^{\circ}$(미처리면) 으로 가공처리 된 시료에는 양면의 접촉각이 확연한 차이가 나타난 걸로 미루어 보아 편면발수효과가 얻어졌다고 판단된다. SEM 측정을 통하여 관찰한 경우, 발수처리 된 시료에서는 불소계 발수제의 흔적이 보였다. 저온 Plasma, Sputter 처리된 시료에서는 처리시간이 높아짐에 따라서 시료표면에 코팅된 불소계 발수제 막들이 점점 파괴되는 것을 관찰할 수 있었다. 그리고 건식가공으로 인하여 처리된 표면에는 Etching작용이 일어나 표면적이 넓어져 친수화가 일어난 것으로 생각된다. 이처럼 저온 Plasma가공과 Sputter가공으로 편발수를 얻을 수 있다면 에너지 절약, 처리공정과 시간단축 등 여러 가지 장점이 기대된다.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.141-145
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• 2013

The aim of this study was to investigate the effect of two male cultivars of asparagus with low different chilling periods on bud breaking, relative spear growth rate, shoot number and yield. Four-month-old plants of two male cultivars of asparagus were dried to impose dormancy and placed in a coldroom at $5^{\circ}C$ to satisfy the chilling requirement for 0, 2, 4, and 6 weeks. After the specified chilling time, the pots were placed in greenhouse. The results showed that mean days to bud break of 'Jersey Giant' significantly decreased with an increasing chilling period from 0 to 6 weeks, but 'Jersey Supreme' was not affected. The relative spear growth rate of 'Jersey Supreme' was significantly stimulated by chilling compared to non-chilled plants. Shoot production and total spear weight of 'Jersey Supreme' tended to be greater than 'Jersey Giant' irrespective of chilling treatments. Following low temperature treatment, 'Jersey Supreme' showed shorter dormant period than 'Jersey Giant', faster growth of spear. The present study showed that asparagus male cultivar at duration of chilling treatment had an affirmative effect on bud breaking, spear growth rates, shoot number and yield of asparagus.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.200-209
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• 1996

It is assumed to be an efficient method for keeping a germinability of weed seeds as long as possible, if a secondary dormancy is not induced by transferring the seeds of which dormancy was broken in wetting condition into drying condition. To investigate its validity, two experiments were carried out on seeds of 9 weed species ; to find out the most effective storage condition in breaking the dormancy of each weed species and to know whether there is a decrease in the germinability by transferring into drying storage condition. The dormancy of Chenopodium album and Stellaria aquatica was released well under the drying condition, but that of Echinochloa crus-galli var. oryzicola by soaking in water. Other weed species were released from dormancy by storage in wetting condition. When the seeds stored in the wetting or soaking condition, are air-dried and then restored at room or low temperature, a decreasing tendency of germinability which might cause a trouble in using them practically, was not observed except on the seeds of Persicaria vulgaris. In the case of Persicaria vulgaris, the low germination since 3 month-storage seemed not to be caused by drying, because a decrease of its germinability was observed with increasing storage period in all of the storage conditions. In contrast, high germination was induced as the seeds of Echinochloa crusgalli var. oryzicola, which were not germinated during the storage in low temperature and wetting condition, were transferred into the room temperature and drying condition. These results suggest that this approach can be one of the efficient methods for keeping a good germinability as long as possible in most weed seeds.

• Journal of the Korea Concrete Institute
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• v.23 no.2
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• pp.225-233
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• 2011

The volume change in concrete takes place with changes in temperature and water content immediately after concrete casting. In the early age stage, the thermal and drying shrinkages can cause cracks that are very crucial to the durability of concrete. It was reported that when the cement with lightly-burnt MgO powder was used, the shrinkage of concrete can be reduced. This study investigates fundamental properties of cement composites with lightly burnt MgO powder by performing various experiments. The stability test results verified that MgO powder in cement composites does not cause any abnormal expansion. Also, the hydrate product analysis results obtained from MgO cement paste showed that MgO powder reduces the shrinkage at the longterm ages. In addition, the cement composites containing the proper amount of MgO powder could improve compressive strength. Finally, the shrinkage reduction from using MgO powder can be optimized by increasing MgO replacement level and curing temperature.

• Korean Journal of Food Science and Technology
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• v.22 no.4
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• pp.434-438
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• 1990

With adding cryoprotectants to red pepper paste and strawberry pulp, the effects of freezing point depression and the energy requirement for storage at $-15^{\circ}C$ were studied. In case of red pepper paste, the freezing point was pressed to $-9.6^{\circ}C$ by adding NaCl(15% w/w) and citric acid after removing stem. And the components of combined cryoprotectants to keep strawberry pulp in the unforzen state at $-15^{\circ}C$ were dextrose(25% w/'w), fructose(17% w/w) sorbitol(8% w/w) and ascorbic acid(0.2%, w/w). Also, when compared with No-treatment, the storage time reduced about 50% and resulted in about $70{\sim}80%$ cut-down in the energy requirement for storage of food products at low-temperature.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.202-209
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• 2014

This study was conducted to investigate the effects of low temperature shipping condition and precooling treatments (forced air and room cooling) on everbearing strawberry through export simulation of 'Goha' and 'Flamenco' cultivars. After harvest, it took two days to prepare export procedure such as precooling, sorting, storage, transportation, quarantine and handling, and then everbearing strawberry was carried out shipping at room ($20-25^{\circ}C$) or low ($8^{\circ}C$) temperature conditions. In the case of shipping at room temperature, weight losses of both cultivars were increased up to 10% after 2 days where 'Goha' being 2% higher than that of ' Flamenco'. In 'Flamenco' cultivar, shipping temperature and precooling treatment were not effective in firmness and soluble solids contents during transporting periods. However, in 'Goha' cultivar, room cooling treatment and low shipping temperature were effective in maintaining firmness until 4 days after shipping. Especially titratable acidity was affected by shipping temperature ($P{\leq}0.001$) and precooling treatments ($P{\leq}0.05$) in 'Goha' cultivar. Also shipping temperature under $8^{\circ}C$ delayed coloring and decay incidence of both strawberry cultivars, and precooling treatments of both forced air and room cooling reduced frequency of decay. The shelf life of everbearing strawberry at low shipping temperature was extended more than 4 days compared with shipping at room temperature. Precooling treatment including forced air or room cooling will be useful for the two cultivars when they are transported at low temperature. In 'Flamenco' cultivar, the effect of forced air and room cooling was similar, whereas in 'Goha' room cooling was more effective.

• Food Science and Preservation
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• v.10 no.1
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• pp.1-5
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• 2003

This study was carried out to extend a marketing shelf-life of the Jeju greenhouse mandarin fruits. Total soluble solids were not showed any significant differences by the temperatures and pre-treatments during the marketing period. Acid content and firmness of the fruits were gradually decreased, which were better in cold than in room temperature treatment. The fruits washed in electrolyzed acid water(pH 2.4∼2.7) maintained freshness higher than those of control Internal CO$_2$concentration of those was 1.0 ％ more or less in the beginning marketing stage, but increased along the marketing period in mom temperature. Especially Internal CO$_2$concentration of wax-coated fruits rapidly increased more than any other, whereas it was a little decreased in cold treatment. After 10 days in room temperature, decay ratio of the fruits was below 4.0% in electrolyzed acid water washing, compared to 10.4% in control. After 30 days in cold temperature, decay ratio was only 3.7% in electrolyzed acid water washing compared to 4.4% of wax-coated treatment and 7.4% of control. The weight loss among the pre-treatments in room temperature had no significant differences and was higher than in cold one.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.512-512
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• 2012

최근 저온 대기압 플라즈마 장치의 개발로 대기 및 수질 환경, 바이오 메디컬분야로의 응용 연구가 활발히 진행되어 공기 중 플라즈마의 살균 및 정화효과에 대한 많은 결과가 발표되어 왔다. 본 연구는 면방전 구조의 DBD플라즈마 소스를 제작하여 He과 Ar 기체를 유입하여 미생물인 E.Coli의 변화를 관찰하였다. 면방전 구조의 DBD플라즈마 소스는 1.8 mm 두께의 유리기판위에 포토리소그라피 공정으로 미소전극을 형성하여 고밀도의 방전 셀을 형성하였으며 방전시 발생하는 열 효과를 제어하기 위하여 냉각장치를 제작하여 장착했다. 또한 유리기판과 포토 리소그라피 공정은 방전영역에 제한없이 다양한 크기의 소스제작이 가능하다. 셀 피치가 $400{\mu}m$이며 $cm^2$ 당 200여개의 방전 셀로 구성되어 있어서 기존 메쉬타입의 DBD플라즈마 장치에 비해 균일하게 플라즈마를 조사할 수 있으며 플라즈마 제트 장치에 비해서는 넓은 면적을 동시에 조사할 수 있게 되었다. Ar 과 He기체를 3 L/min의 유량으로 방전공간에 유입하면서 1kV의 구동전압으로 플라즈마를 발생 하였으며, 플라즈마의 조사시간을 20 s, 40 s, 60 s 간격으로 변화를 주어 E.Coli의 변화를 관찰하였다.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.293-298
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• 1997

The changes of microorganisms, pH, color and flavor were examined in the chicken treated with O％, 1%, 2%, and 3% lactic acid solutions during the storage at 4$^{\circ}C$. Lactic acid treatment inhibited the growth of mesophiles, psychrotrophs, and enteric bacilli as the concentration increased, however, it was not effective on yeasts and molds. Extension of lag phase for mesophilic bacteria and suppression of log phase for psychrotrophs and enteric bacilli were observed in the growth inhibition patterns. The pH of the chicken increased during the storage and antimicrobial effect of lactic acid appears to be due to mainly the decrease of pH. No flavor change of the chicken was observed by any lactic acid treatment, however, 3％ lactic acid caused discoloration of the chicken.