• Title/Summary/Keyword: Low temperature GaN

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Effect of PGRs and various co-packing materials on storage quality in 'Shine Muscat' grapes

  • Kim, Sung-Joo;Kim, Yu-Rim;Choi, Cheol;Ahn, Young-Jik;Choi, Hyun-Jin;Chun, Jong-Pil
    • Korean Journal of Agricultural Science
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    • v.48 no.2
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    • pp.241-250
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    • 2021
  • This investigation assessed the berry quality after two months of low-temperature storage (3 ± 1℃) of 'Shine Muscat' grapes, which were treated with CPPU (N-[2-chloro-4-pyridyl]-N'-phenylurea) or TDZ (1-phenyl-3-[1,2,3-thiadiazol-5-yl] urea) in combination with gibbrellic acid (GA3). The berry shatter rate was the lowest (1%) in 4 cm + CPPU treatment, while it was the highest (2.4%) in 3 cm floral length treated with CPPU. On the other hand, the 4 cm + TDZ treatment resulted in a shatter rate of 2.0%, which was twice as high as that observed after 4 cm + CPPU treatment. The 4 cm + TDZ treatment resulted in a 5.5% berry decay rate, which was the highest among all treatments. Alternatives to using a sulfur dioxide (SD) pad to maintain the quality of 'Shine Muscat' grapes, namely, using ethylene scrubbers (ESs, 3 g × 2 sachet) and alcohol releasers (ARs, 2 g × 2 sachet) in a 2 kg carton package for export, were explored in this study. The berry shatter rate with ES treatment (1.0%) was found to be comparable to that with SD treatment (0.6%) during three months of cold storage. Regarding the berry decay rate, that of the untreated control surged to 36.0% in the three months of storage, followed by 19.9% and 15.5% in samples subjected to AR and ES treatments respectively. Compared with the untreated control, the samples subjected to SD treatment showed a decay rate of 2.2%, which was the most effective in reducing berry decay by 95%. These results demonstrated that SD pad treatment of 'Shine Muscat' grapes was the most effective method of maintaining berry quality, and ES treatment partially reduced the berry shatter and berry decay rates.

Analysis of An Anomalous Hump Phenomenon in Low-temperature Poly-Si Thin Film Transistors (저온 다결정 실리콘 박막 트랜지스터의 비정상적인 Hump 현상 분석)

  • Kim, Yu-Mi;Jeong, Kwang-Seok;Yun, Ho-Jin;Yang, Seung-Dong;Lee, Sang-Youl;Lee, Hi-Deok;Lee, Ga-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.11
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    • pp.900-904
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    • 2011
  • In this paper, we investigated an anomalous hump phenomenon under the positive bias stress in p-type LTPS TFTs. The devices with inferior electrical performance also show larger hump phenomenon. which can be explained by the sub-channel induced from trapped electrons under thinner gate oxide region. We can confirm that the devices with larger hump have larger interface trap density ($D_{it}$) and grain boundary trap density ($N_{trap}$) extracted by low-high frequency capacitance method and Levinson-Proano method, respectively. From the C-V with I-V transfer characteristics, the trapped electrons causing hump seem to be generated particularly from the S/D and gate overlapped region. Based on these analysis, the major cause of an anomalous hump phenomenon under the positive bias stress in p-type poly-Si TFTs is explained by the GIDL occurring in the S/D and gate overlapped region and the traps existing in the channel edge region where the gate oxide becomes thinner, which can be inferred by the fact that the magnitude of the hump is dependent on the average trap densities.

Hydrogen shallow donors in ZnO and $SnO_2$ thin films prepared by sputtering methods

  • Kim, Dong-Ho;Kim, Hyeon-Beom;Kim, Hye-Ri;Lee, Geon-Hwan;Song, Pung-Geun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.145-145
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    • 2010
  • In this paper, we report that the effects of hydrogen doping on the electrical and optical properties of typical transparent conducting oxide films such as ZnO and $SnO_2$ prepared by magnetron sputtering. Recently, density functional theory (DFT) calculations have shown strong evidence that hydrogen acts as a source of n-type conductivity in ZnO. In this work, the beneficial effect of hydrogen incorporation on Ga-doped ZnO thin films was demonstrated. It was found that hydrogen doping results a noticeable improvement of the conductivity mainly due to the increases in carrier concentration. Extent of the improvement was found to be quite dependent on the deposition temperature. A low resistivity of $4.0{\times}10^{-4}\;{\Omega}{\cdot}cm$ was obtained for the film grown at $160^{\circ}C$ with $H_2$ 10% in sputtering gas. However, the beneficial effect of hydrogen doping was not observed for the films deposited at $270^{\circ}C$. Variations of the electrical transport properties upon vacuum annealing showed that the difference is attributed to the thermal stability of interstitial hydrogen atoms in the films. Theoretical calculations also suggested that hydrogen forms a shallow-donor state in $SnO_2$, even though no experimental determination has yet been performed. We prepared undoped $SnO_2$ thin films by RF magnetron sputtering under various hydrogen contents in sputtering ambient and then exposed them to H-plasma. Our results clearly showed that the hydrogen incorporation in $SnO_2$ leads to the increase in carrier concentration. Our experimental observation supports the fact that hydrogen acting as a shallow donor seems to be a general feature of the TCOs.

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Improvement of Seedling Stand and Lodging Prevention in Direct Seeded Rice (벼 직파재배(直播栽培) 입묘율향상(立苗率向上)과 도복경감(倒伏輕減))

  • Oh, Yun-Jin;Kim, Chung-Kon
    • Korean Journal of Weed Science
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    • v.12 no.3
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    • pp.200-222
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    • 1992
  • The results of recent researches for improvement of seedling stand in direct seeded rice on the dry paddy in Korea were summarized as the following ; a variety to be cultivated should be chosen the characteristics of high percentage germination under low temperature, shorter period of shoot emergence, and better growth of the mesocotyl and shoots. Meanwhile, there was 40% increase in seedling stand at the treatment of removal of the seed awn under using the drill seeder. After seeding the rice seed covered with soil of 3cm depth was better seedling emergence and also there was the hightest seedling emergence at the 70% of moisture content of the soil. In addition, the application of the Release containing GA 10% enabled to increase the seedling stand and furthermore it was effective under deep seeding depth. The optimum seeding date should be seeded around May 10 when mean air temperature is above 12-13$^{\circ}C$ so that may establish more less 70% in seedling stand. Based on an appropriate seedling stand of 150/$m^2$, the optimum seeding rate was 5kg/10a. It was the best in seeding method using drill seeder and the most desirable recommended seeding method was the drill seeder in terms of seedling stand. In order to improve seedling stand water management was more effective in canal irrigation and in drainage at 6hr after irrigation following by the seeding process. On the other hand, for the increase of seedling stand under flooded condition a variety might have characters being better germination at low concentration of dissolved oxygen and vertically deeper growing of the crown root. Also, seedling stand was able to increase with the seed coating of $CaO_2$in the flooded soil. It was possible to be seeded on the early part of May being mean air temperature of avove 10$^{\circ}C$ and the optimum seeding rate was 5kg/10a. For an effective water management water would be flooded up to 3cm depth for 2-3 weeks after seeding. The rice plant grown under the direct seeded cultivation might be not so much strong in lodging resistance compared to that grown under the transplanting and moreover direct seeded rice cultivation under flooded condition would be more weak growth of the rice plant than that on dry paddy. Meanwhile, the lodging would be affected by the seeding rate, the soil depth after seeding. and seeding method even in the same variety. In particular, roots in the lodging pattern of direct seeded rice cultivation under flooded condition were largely distributed on the soil surface so that resulted easily in the lodging. In general, the lodging resistance would be greater as seeding rate and amount of N fertilizer application are lower and soil depth after seeding is higher. Among the introduction of different seeding method the high ridged drill seeding method on dry paddy soil resulted in the lowest in the lodging index and also it was lower in the drill seeding method than in the scattering seeding method under flooded condition. In case of more than 150 seedlings per $m^2$ there was a severe lodging due to high lodging index at the 3rd and 4th internodes. The effective lodging prevention was able to at the treatment of the Inabenfide at 45 days before heading and the Uniconazol at 15 days before heading which caused the shortage by 10-15cm in culm length. Also, fertilizer management using split application of nitrogen would be contributed the reduction of lodging at the rate of 20-30-20-20-10%(basal-5th leaf stage-7th leaf stage-panicle initiation stage-heading stage) on the dry paddy soil.

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