• Title, Summary, Keyword: Formulation changes

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Experimental Study on the Infiltration Loss in Plastic Greenhouses Equipped with Thermal Curtains (보온커튼을 설치한 플라스틱 온실의 틈새환기전열량 실측조사)

  • Nam, Sang-Woon;Shin, Hyun-Ho
    • Protected Horticulture and Plant Factory
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    • v.24 no.2
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    • pp.100-105
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    • 2015
  • The calculation method of infiltration loss in greenhouse has different ideas in each design standard, so there is a big difference in each method according to the size of greenhouses, it is necessary to establish a more accurate method that can be applied to the domestic. In order to provide basic data for the formulation of the calculation method of greenhouse heating load, we measured the infiltration rates using the tracer gas method in plastic greenhouses equipped with various thermal curtains. And then the calculation methods of infiltration loss in greenhouses were reviewed. Infiltration rates of the multi-span and single-span greenhouses were measured in the range of $0.042{\sim}0.245h^{-1}$ and $0.056{\sim}0.336h^{-1}$ respectively, single-span greenhouses appeared to be slightly larger. Infiltration rate of the greenhouse has been shown to significantly decrease depending on the number of thermal curtain layers without separation of single-span and multi-span. As the temperature differences between indoor and outdoor increase, the infiltration rates tended to increase. In the range of low wind speed during the experiments, changes of infiltration rate according to the outdoor wind speed could not find a consistent trend. Infiltration rates for the greenhouse heating design need to present the values at the appropriate temperature difference between indoor and outdoor. The change in the infiltration rate according to the wind speed does not need to be considered because the maximum heating load is calculated at a low wind speed range. However the correction factors to increase slightly the maximum heating load including the overall heat transfer coefficient should be applied at the strong wind regions. After reviewing the calculation method of infiltration loss, a method of using the infiltration heat transfer coefficient and the greenhouse covering area was found to have a problem, a method of using the infiltration rate and the greenhouse volume was determined to be reasonable.

Comparison of Flavonoid Contents and Antioxidant Activity of Yuzu (Citrus junos Sieb. ex Tanaka) Based on Harvest Time (산지별 유자의 수확시기에 따른 플라보노이드 함량 및 항산화활성 비교)

  • Moon, So Hyun;Assefa, Awraris Derbie;Ko, Eun Young;Park, Se Won
    • Horticultural Science & Technology
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    • v.33 no.2
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    • pp.283-291
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    • 2015
  • The aim of this study was to evaluate the changes of fruit quality, flavonoid contents and antioxidant activity of Yuzu (Citrus junos Sieb. ex Tanaka) from Go-heung and Jeju according to harvest time. Samples were harvested from August to December on the $1^{st}$ of every month. August and September samples were green colored, whereas November and December samples were yellow. The fruit shape index decreased, changing from globular to elliptical, whereas the $^{\circ}birx$ increased with ripening stage. The yuzu from Jeju was larger than that from Go-heung in each month of cultivation. August samples exhibited the highest amounts of phenolic compounds. In addition, samples from Jeju had higher total phenolic content than those from Go-heung. The content of phenolic compounds decreased with ripening until October and then increased subsequently. Antioxidant activity of the yuzu was evaluated by FRAP and DPPH methods. The antioxidant activity showed a similar trend as total phenolic content. Immature yuzu fruit was found to exhibit the highest amount of flavonoids such as naringin and hesperidin. November and December samples showed almost the same contents of flavonoids. The flavonoid content of yuzu fruit harvested from Jeju was higher than that from Go-heung. Overall, the samples harvested at the early stage, in the month of August, exhibited the highest flavonoid content, phenolic content and antioxidant activity. As the health benefits of these compounds has been demonstrated in various studies, the immature yuzu appears to be preferable for use as a raw material for formulation of pharmaceutical products as well as for functional food production after a proper in-vivo and in-vitro medical tests.

Performance of Seedling Grafts of Tomato as Influenced by Root Medium Formulations and Leaching Fractions in Irrigation or Fertigation (혼합상토 조성과 관수 또는 관비시 배액률이 토마토 접목묘 생장에 미치는 영향)

  • Choi, Jong Myung
    • Protected Horticulture and Plant Factory
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    • v.23 no.3
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    • pp.235-243
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    • 2014
  • This research was conducted to investigate the influence of leaching fractions (LF) in each irrigation or fertigation on plant growth and changes in chemical properties of root media during the production of seedling grafts of tomato. Two root media containing Sphagnum peat moss plus vermiculite (5:5, v/v, PV) and coir dust plus vermiculite (5:5, v/v, CV) were formulated and pre-planting fertilizers were incorporated during formulation. Then, each medium was packed into 50 cell (volume 33 cc) and 105 cell (volume 18 cc) trays and the rootstock (cv. J3B Strong) and scion (cv. Sunmyung) were grown, respectively. The seedlings were grafted at 31 days after sowing and then the cut seedling grafts (Sunmyung scion/J3B Strong rootstock) were planted into 50 cell plug trays containing each of the two root media. After induction of the graft union and new adventitious roots for 7 days, the seedling grafts were fed with fertilizer solution once a week containing 4 different N concentrations (0, 50, 100, $200mg{\cdot}L^{-1}$). When determined after 31 days from seed sowing, the highest fresh weights of the root stock seedlings were obtained with 0.75 LF in PV (8.96g/seedling) and CV (7.11g/seedling) mixes. The EC of the both mixes were 0.93 and $1.09dS{\cdot}m^{-1}$, respectively. The fresh weights of the scion seedlings 31 days after seed sowing were 4.29g with 0.50 LF in the PV and 3.13g with 0.50 LF in the CV. The root medium ECs of the two treatments were 0.76 and $1.34dS{\cdot}m^{-1}$, respectively. Fresh weights of the seedling grafts grown for 31 days were greatly influenced by post-planting fertilizer concentrations. The heavier plants were obtained in $100mg{\cdot}L^{-1}$ N treatment than any other treatments in same mixes. The substrate ECs in these two treatments were 0.98 and $1.93dS{\cdot}m^{-1}$, respectively, indicating that the desirable range of soluble salts in soil extracts is higher in the CV mix than the PV mix. Results of this study suggest that optimum EC range is different in each medium and LF need to be adjusted differently for each root medium to produce high quality seedling grafts of tomato.

A Study on the Stability of the Cream Containing Glycyrrhiza uralensis Extract (한국산 감초 추출물 함유 크림의 안정성 평가)

  • Kim, Hye Jin;Jang, Ha Na;Bae, Jeong Yun;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.2
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    • pp.117-125
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    • 2013
  • In this study, The stability of a cream containing the ethyl acetate fraction of 50% ethanol extracts from Glycyrrhiza uralensis (G. uralensis) cultured in Korea was investigated. pH, absorbance, viscosity and color difference of the cream containing 0.20% ethyl acetate fraction of the aforementioned G. uralensis extracts were measured under 4 different temperature conditions ($4^{\circ}C$ $25^{\circ}C$ $37^{\circ}C$ and $45^{\circ}C$) and under the sun light at 2 week intervals for 12 weeks. pH changes of a control cream without the extracts and the sample cream containing 0.20% ethyl acetate fraction of G. uralensis extracts were 0.66 and 0.44, respectively. There were no significant pH differences between the sample and the control under the sun. Viscosities of the control cream and the sample cream decreased by 2,483 cPs and 2,893 cPs respectively. So, the sample cream showed a bigger decline (410 cP) in viscosity than the control cream. The ethyl acetate fraction of G. uralensis extracts did not affect the stability of the cream. Absorbance of ethanol solution of the ethyl acetate fraction decreased 30.00% at 276 nm under the sun. On the other hand, the absorbance of the sample cream containing the ethyl acetate fraction decreased 12.02%. The stability of the G. uralensis extracts was better in cream formulation than in ethanol solution. The total color differences of all creams increased slightly during the study period under various conditions. The results appeared to indicate the color stability of the cream containing 0.20% ethyl acetate fraction of G. uralensis extracts. It is suggested that further study is needed to provide more information to the manufacturers who are seeking for the application of the G. uralensis extracts to improve the anti-oxidant and stability of cosmetic products.