• Title/Summary/Keyword: Blackening

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Effects of Pre-drying Process on the Quality of 'Fuyu' Persimmons (예건 처리 온도에 따른 단감(부유)의 품질 변화 조사)

  • Park, Sung Jin;Cho, Kwang Sik;Kim, Jun Tae
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.21 no.2
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    • pp.79-84
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    • 2015
  • Pre-drying of 'Fuyu' persimmon was performed right after harvesting from a farm. Pre-drying conditions were varied with room temperature (RT) for 1 day to 7 days, low temperature (LT, at $20{\sim}30^{\circ}C$) for 1 day to 4 days, high temperature (HT, at $30{\sim}40^{\circ}C$) for 3 h to 12 h, and ultra-high temperature (UT, at $50{\sim}60^{\circ}C$) for 30 min to 120 min. Weight loss of pre-dried persimmon was increased from 1.62% up to 2.96% with increased pre-drying temperature and time. Pre-drying at RT resulted more significant weight loss of persimmon compared to that of pre-drying at HT. Minimum firmness loss of persimmon stored at $0^{\circ}C$ for 100 days was obtained at the condition of HT for 6 h. Rate of peel blackening was decreased from 31.5% to 16.4% and 10.9% by pre-drying at HT for 6 h and 9 h, respectively.

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Effect of antioxidant treatment in axillary culture medium of walnut(Juglans sinensis) (호두 액아 배양시 산화방지제 처리 효과)

  • Kwon, Young Hee;Lee, Joung Kwan;Park, Jae Seong;Huh, Yoon Sun
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.38-38
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    • 2018
  • 최근 호두 기내 소비량은 급증하나 대부분 실생묘로 조림되어 결실까지 장기간 소요되며, 무성 번식률이 낮아 보급확대가 어렵다. 본 연구는 호두나무 관행 묘목 번식법 개선이 가능한 우량 국산묘 대량증식 기술 개발로 최적 배양조건을 구명하고자 수행하였디. 호두나무 등 목본류는 식물 조직배양 기본배지에서 산화방지제를 첨가하여 사용하는 경우, 배양체에서 생기는 페놀 화합물(Phenolic compound)의 작용을 억제하여 배양 식물체의 갈변(Browning) 또는 흑변(Blackening) 현상을 감소시키는 효과가 있다. 페놀 추출물은 배지로 빠져나와 갈변시키며 생존율을 저하시키는 원인이 되고 이를 제거하는 산화방지제는 배양 식물체의 생산효율을 높이는 효과를 나타내는 강력한 항산화제(Antioxidant) 역할을 한다. 호두나무의 액아를 배양하게 되면 조직 및 배지의 갈변화가 심하게 일어나는데, 휴면 정도가 깊을 수록 정단에서 추출되는 페놀성 물질의 함량이 증가하며, 식물 조직 내 페놀성 물질의 함량 정도와 배양의 고사율과는 상관관계가 있다. 이러한 식물 배양체에서 생기는 페놀 화합물에 의해 발생되는 배양상의 문제점을 해결하기 위하여 계대배양을 자주해 주거나 활성탄(Activated charcoal), Ascorbic Acid 등의 첨가물을 배지에 추가하는 방법이 있다. 이에 따라 호두 '신령' 품종의 액아배양의 페놀집적을 제거하기 위해 배지 내에 산화방지제 첨가물질 등을 농도별로 처리하였다. 호두나무 액아 배양 후 8주차 산화화방지제 첨가물질의 농도별 처리 효과는 생존율은 85.3%를 보였으며, 신초 형성율 76.4%, 신초수 1.9개/주, 신초장 27mm/주의 양호한 결과를 나타냈으며, 페놀 제거 및 유식물체 고사 억제 효과를 보였다.

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Characteristics and Origin of Salts in the Black Surface Layer of Stone Monuments (석조기념물 흑색표면층에 있는 염의 특성과 기원)

  • Do, Jinyoung
    • Journal of Conservation Science
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    • v.12 no.1 s.15
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    • pp.15-25
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    • 2003
  • It is well known that the salt in stoneworks impact on damage of stone by various methods. Various kind of salt is detected in high content in the black surface layer of stone monuments and it is required about origin and roles of salts on blackening to considerate. In this study have been investigated the characteristics of salt in the black crust of sandstone and limestone which used in historical monuments in Berlin, Germany. Salt was analyzed for cation by Atomic Absorption and Atomic Emission Spectroscopy and for anion by ion Chromatograph. The representative ions are $Ca^{2+}\;and\;SO_4^{-2}$ in all samples and the most obvious combinations was proved in calcium sulfate by statistical methods. Because gypsum was detected by X-ray diffraction analyses in the black crusts, this calcium sulfate was confirmed by 2 hydrate type. The probable origin of Ca is air particle in atmosphere around sandstone and calcite in mother rock in limestone, and that of S is polluted air and mortar which used as conservation works.

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Monitoring and Environment-friendly Management of Blueberry Gall Midge, Dasineura oxycoccana (Diptera: Cecidomyiidae), on Blueberry (블루베리에서 블루베리혹파리(Dasineura oxycoccana) 발생 예찰 및 친환경 방제)

  • Kang, Taek-Jun;Cho, Myoung-Rae;Ahn, Seung-Joon;Kim, Hyeong-Hwan;Kim, Se-Jin;Lee, Seong-Chan;Lee, Heung-Sik
    • Korean Journal of Organic Agriculture
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    • v.20 no.4
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    • pp.607-618
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    • 2012
  • The blueberry gall midge, Dasineura oxycoccana (Diptera: Cecidomyiidae), has known as a key pest of blueberries in the southeastern United States, Europe and Canada. It can cause considerable damage to developing flower buds and also injure vegetative growth by distorting and blackening shoot tips on blueberries. In 2010, same damage symptoms were observed on blueberries, Vaccinium spp., in Hwaseong-si, Gyeonggi-do. And, D. oxycoccana was identified from the farms and it was designated as a quarantine pest in Korea. The occurrences of D. oxycoccana and its damages were investigated in the blueberry greenhouse in 2011. Nationwide survey revealed that most of the blueberry greenhouses were infected by D. oxycoccana. An environment-friendly management method for D. oxycoccana was developed by changing soil environment in the blueberry greenhouse.

Effect of Gamma Irradiation and Post-Irradaition Treatment of Preservatives on the Cut Flower Longevity of Rose and Mum. (감마선 조사와 조사 후 보존제 처리가 절화 장미 및 국화의 수명에 미치는 영향)

  • 박인환;정연승;이월순;권중호;변명우
    • Food Science and Preservation
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    • v.6 no.3
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    • pp.286-291
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    • 1999
  • This study was carried out to determine the effect of dose and timing of gamma irradiation and post-irradiation treatment with some preservatives of cut flowers on their longevity of rose and chrysanthemum. Cut roses which were soaked in 2% sugar solution persist to 0.75 kGy irradiation treatments. In post-treatments with some preservative solutions, the mixture group of 2% sucrose,2000m silver nitrate and 3.0% crysal were available in flower quality, but the 200 ppm silver nitrate solution treatment showed serious blackening of floral stems and resulted On negative effect in flower quality. Effect of gamma irradiation and all preservative solutions on the cut mum longevity were showed almost same tendency with rose cut flower longevity experiments. The 2% sugar dipping solution in mum cut flower showed the most superior preservative effect compared with the my other preservative solutions tested. Also non-irradiated treatment extended to flower up to complete wilt.

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Packages of Persimmons Exported from Korea to USA and Temperature Conditions during Sea Transport (미국 수출 단감 포장의 현황 및 수송 중 컨테이너 온도관리 실태)

  • Ahn, Gwang-Hwan;Lee, Dong-Sun
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.15 no.1
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    • pp.17-23
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    • 2009
  • Current status on consumption and packaging of sweet persimmons in USA was surveyed by visiting the market, and three sea shipments were conducted as model export trial from Korean to USA with measurement in ship container temperature and fruit quality. Strategy to promote the export of Korean persimmons was derived. There have been gradual decrease in the price of persimmons due to their increases production, but there seems potential growth in consumption of the fruits from Asian, Hispanic and American people. Compared to the fruits from other countries, Korean persimmons are desired to have higher soluble solid content with stronger red color, but too large sizes are not favored in American market. There has often been temperature fluctuation in shipment container during the sea transport to USA, resulting in surface blackening, skin black spotting and flesh softening. Plastic bag packages with inappropriate unitizing crimping were found to sometimes build up unproper modified atmosphere (high $O_2$ and low $CO_2$) giving high rate of physiological injury.

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A Study on Transparency and Characteristics of Natural Adhesives Made of Urushiol and Glue (우루시올과 아교를 배합한 천연 접착제의 투명성 및 접착 특성 연구)

  • Kim, Eun Kyung;Ahn, Sun Ah;Jang, Sungyoon
    • Journal of Conservation Science
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    • v.31 no.2
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    • pp.115-123
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    • 2015
  • This study aims to increase the transparency of the natural adhesives made with lacquer and glue. For the purpose, samples were prepared by mixing urushiol with glue in varied proportion and the characteristics and adhesive properties were investigated. By adding glue on urushiol, IR spectra of the natural adhesives became similar to that of glue as the N-H band related with protein of glue increased, while that of methylene C-H bond related to urushiol decreased. Samples were dried within a day and maintained a bright color without blackening by oxidation during the curing process. The natural adhesives with urushiol and glue showed various range of viscosity and tensile shear strength as Cemedine C or Epoxy resin according to mixing ratio. In addition, the sample of mixing ratio of 6:4 showed bright and transparency in appearance and tensile shear strength similar to that of Araldite AY103-1/HY956 for earthenware layer.

Boron deficiency of sunflower (Helianthus annuus.) (해바라기의 붕소결핍(硼素缺乏))

  • Park, Hoon;Yu, Ik Sang
    • Korean Journal of Soil Science and Fertilizer
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    • v.8 no.4
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    • pp.195-198
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    • 1975
  • Boron deficiency appeared as a cause of poor growth of sunflower(Helianthus annuus) according to soil and plant analysis. The investigated results are as follows; 1. Boron deficiency was due to low content of available boron (hot water soluble) in soil and clitical concentration appeared as 0.17 ppm. 2. Clitical concentrations in plant appeared to be 20 ppm for head(flower), 25 for leaf, 15 for stem and 10 for root. Boron concentration among positional leaves was greatly decreasing in the upper leaves. 3. Soils low in boron were relatively higher in calcium, silica and pH than in normal soil but relationship between boron and organic matter or other nutrients was uncertain. 4. The content of Ca and P is high in the head of boron deficient plant but low in root. Plants deficient in boron also showed a tendency of high N and low K but no clear tendency was shown in Mg and Fe. 5. Symptoms of boron deficinicy were yellowing of upper leaves, browning and drying of upper part of stem, cracking and blackening of stem and roots resulting short stem and poor growth.

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Synthesis of Ag-doped black ZnO nano-catalysts for the utilization of visible-light (가시광선 활용을 위한 Ag 도핑 흑색 ZnO 나노 광촉매 합성)

  • Ui-Jun Kim;Hye-Min Kim;Seung-Hyo Lee
    • Journal of the Korean institute of surface engineering
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    • v.56 no.3
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    • pp.208-218
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    • 2023
  • Photocatalysts are advanced materials which accelerate the photoreaction by providing ordinary reactions with other pathways. The catalysts have various advantages, such as low-cost, low operating temperature and pressure, and long-term use. They are applied to environmental and energy field, including the air and water purification, water splitting for hydrogen production, sterilization and self-cleaning surfaces. However, commercial photocatalysts only absorb ultraviolet light between 100 and 400 nm of wavelength which comprises only 5% in sunlight due to the wide band gap. In addition, rapid recombination of electron-hole pairs reduces the photocatalytic performance. Recently, studies on blackening photocatalysts by laser, thermal, and plasma treatments have been conducted to enhance the absorption of visible light and photocatalytic activity. The disordered structures could yield mid-gap states and vacancies could cause charge carrier trapping. Herein, liquid phase plasma (LPP) is adopted to synthesize Ag-doped black ZnO for the utilization of visible-light. The physical and chemical characteristics of the synthesized photocatalysts are analyzed by SEM/EDS, XRD, XPS and the optical properties of them are investigated using UV/Vis DRS and PL analyses. Lastly, the photocatalytic activity was evaluated using methylene blue as a pollutant.

Dining-out Tendencies of Foreign Residents for Meat Dishes in Korea (국내거주 외국인들의 고기요리에 대한 소비행태)

  • Kim, Eun-Mi;Seo, Sang-Hee;Kwon, Ki-Hyun;Lee, Min-A;Hong, Sang-Pil;Lee, Eun-Jung
    • Journal of the Korean Society of Food Culture
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    • v.25 no.5
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    • pp.568-577
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    • 2010
  • This study was conducted to provide fundamental data for the Korean food service industry by researching the awareness and consumption tendencies of 180 domestic foreign residents towards Korean meat dishes. The results showed differences in the preferred types of food depending on gender; men tended to like meats, followed by stews, and rice, whereas women tended to like meats, followed by rice, and stew. The foreigners who participated in this research dined at Korean restaurants at least 20 times per month on average, regardless of their place of residence. Dishes with the lowest intake were suyuk (boiled meat, 66.7%) and dakbokkeumtang (sauteed chicken stew, 67.8%) and dishes with the highest intake tended to be roasts, which are relatively easier to prepare. The types of preferred food were in the order of galbi, bulgogi, and dakgalbi, and the least favored foods were yukgaejang, followed by suyuk, and seollengtang. "It is delicious" was the response found most frequently as a reason for preference regardless of the type of meat dish, and the reason for distaste was: "It is not delicious" This demonstrated that taste was the most important factor when visiting a Korean restaurant. Unexpectedly, sirloin roast, beef galbi stew, chicken stew, samgyetang, and dakbokumtang were not favored because of unfamiliar aroma and taste. In the case of galbi, "It is not very sanitary" was the main factor in responses. For areas of improvement, food sanitation, meat smells left on clothes, and smoke generated during roasting were factors with a high degree of importance, whereas the use of gas burners and the blackening of bowls were found to have a lower degree of importance.