• Title/Summary/Keyword: 포장기

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A Study on Application of Warm-Mix Quiet Pavement Using Fine-Size Aggregate (소입경 골재를 이용한 중온 저소음 아스팔트 포장의 적용 연구)

  • Jo, Shinhaeng;Baek, Yujin;Kim, Nakseok
    • Journal of the Society of Disaster Information
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    • v.9 no.1
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    • pp.56-64
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    • 2013

  • The study examines the quiet pavement using fine-size aggregates and warm-mix technique to reduce traffic noise. In order to evaluate the quality of pavement, mix design and laboratory tests were carried out. Test results showed that using 10mm aggregates can reduce the cantabro loss compared with 13mm aggregates due to increase contact area between aggregates. Mixing and compaction temperatures of warm mix quiet pavement should be determined by gyratory compactor test because it is used high viscosity asphalt binder. Using warm-mix additive could reduce compaction temperature by about $15^{\circ}C$. Noise measurement and permeability tests were conducted at the test road for evaluation of the field performance. All of quiet pavements meet the standard of permeability and have sufficient porosity. Noise reduction of the quiet pavement using fine-size aggregates is more effective than that using 13mm aggregates. In particular, the effect of noise reduction was noticeable at low speeds.

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Non-Chemical or Low-Chemical Control Measures against Key Insect Pests and Rats in the Ginseng Fields (인삼 포장에서의 해충 및 쥐의 비농약적 또는 저농약적 방제법)

  • Kim, Ki-Whang
    • Korean journal of applied entomology
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    • v.39 no.4
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    • pp.281-286
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    • 2000

  • Non-chemical or low-chemical control measures against key insect pests and rats in the ginseng field were studied from 1993 through 1999. Broadcasting chemicals beside the ginseng field in the oviposition period showed the same control effect on the adults of the Korean black chafer, Holotrichia diomphalia, as broadcasting at the ginseng ridge. Ginseng damage by adults of African mole cricket, Gryl1ota1pa africana, were reduced considerably by broadcasting chemicals beside the ginseng field. The larvae of wheat wireworm, Ectinus sericeus, were attracted effectively to potatoes in the ginseng field. Spreads of the mealybug, Pseudococcus comstocki, were very slow in the ginseng field, indicating that it is possible to eradicate the early colonies of Pseudococcus comstocki effectively. The rat repeller, Dekur $500S^{showed}$ a significant control effect of rats in the ginseng field.

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Heading date and final Leaf Number as Affected by Sowing Date and Prediction of Heading Date Based on Leaf Appearance Model in Rice (벼 파종기에 따른 출수기 및 최종 엽수 변화와 출엽 모델에 의한 출수기 예측)

  • 이충근;이변우;신진철;윤영환
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.3
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    • pp.195-201
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    • 2001

  • Sowing date experiments were carried out by employing a rice variety "Kwanganbyeo" in both field and phytotron with natural daylength. In phytotron, temperatures were controlled at daily mean of 21$^{\circ}C$ and 24$^{\circ}C$. The responses of final leaf number and beading date were analyzed in relation to daylength during photo-sensitive period (PSP). Based on the component models predicting the final leaf number and leaf appearance rate, a rice phenology model was established and verified. Days from sowing to flowering (DSF) were shortened and final number of leaves (FNL) increased as sowing dates were delayed from 25 April to 5 June in field and phytotron. The increased leaf appearance rate (LAR) and the reduced FNL, respectively, due to the higher temperature and the shorter daylength in delayed sowings in the field brought about greater shortening of DSF than in the phytotron where only FNL was reduced by shorter daylength in delayed sewings. FNL showed very close relationship with the average daylength during PSP of six-leaf stage to panicle initiation, being well fitted to the following rational function ($R^2$=0.98):(equation omitted) where D is daylength and a, b, and c are the constants that were estimated as 14.694, -0.992, and -0.068 in Kwanganbyeo, respectively. The rice phonology model, which was composed of two component models for LAR and FNL, predicted DSF very accurately. The differences between the observed and predicted DSF was less than two days in the sewing date field experiments in 1999 and 2000 of which data were not used for the model construction.struction.

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Effects of packaging methods on the freshness during storage of lettuce harvested in summer season of Korea (고온기 결구상추의 수확 후 포장조건에 따른 선도유지 효과)

  • Chang, Min-Sun;Lee, Jung-Soo
    • Food Science and Preservation
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    • v.24 no.2
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    • pp.159-167
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    • 2017

  • This study was investigated the effects of maintaining the freshness and stabilization of supply and demand for lettuce (Lactuca sativa L.) by packaging methods in summer. Post-harvest lettuces were packaged by corrugated box, polypropylene (P) box, and individual wrapping using polyvinyl chloride (PVC) film. Then, the lettuce samples were stored at $2^{\circ}C$ and evaluated the change of quality during storage. The lettuces wrapped individually with PVC film had lower weight loss rate, color change, and browning index compared to lettuces packaged by corrugated box and P box. The SPAD value and hardness were higher in lettuces wrapped individually with PVC film than other packaging methods. The lettuces wrapped individually with PVC film were showed the highest total phenolic contents and DPPH radical scavenging activity, but there were no significantly differences by packaging methods. The lettuces packaged by corrugated box were showed the inside browning after 14 days. However, the lettuces wrapped individually with PVC film were showed the best appearance. Therefore, the packaging method of wrapped individually with PVC film were effective in maintaining the freshness during 21 days and helpful for the stabilization of supply and demand for lettuce in summer.

  • https://doi.org/10.11002/kjfp.2017.24.2.159 인용 PDF KSCI