• Title/Summary/Keyword: natural condition

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Effect of Intensity of Unconditional Stimulus on Reconsolidation of Contextual Fear Memory

  • Kwak, Chul-Jung;Choi, Jun-Hyeok;Bakes, Joseph T.;Lee, Kyung-Min;Kaang, Bong-Kiun
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.5
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    • pp.293-296
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    • 2012
  • Memory reconsolidation is ubiquitous across species and various memory tasks. It is a dynamic process in which memory is modified and/or updated. In experimental conditions, memory reconsolidation is usually characterized by the fact that the consolidated memory is disrupted by a combination of memory reactivation and inhibition of protein synthesis. However, under some experimental conditions, the reactivated memory is not disrupted by inhibition of protein synthesis. This so called "boundary condition" of reconsolidation may be related to memory strength. In Pavlovian fear conditioning, the intensity of unconditional stimulus (US) determines the strength of the fear memory. In this study, we examined the effect of the intensity of US on the reconsolidation of contextual fear memory. Strong contextual fear memory, which is conditioned with strong US, is not disrupted by inhibition of protein synthesis after its reactivation; however, a weak fear memory is often disrupted. This suggests that a US of strong intensity can inhibit reconsolidation of contextual fear memory.

Sensorless Control Algorithm of a Surface Mounted PM Synchronous Motor Under Naturally Rotating by Load (외부부하에 의해 회전중인 표면부착형 영구자석동기전동기의 센서리스 제어 알고리즘)

  • Lee, Han-Sol;Cho, Kwan-Yuhl;Kim, Hag-Wone
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.1
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    • pp.16-23
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    • 2018
  • PM synchronous motor may be rotated to an arbitrary direction and speed by outside wind under natural condition in cases where the fan is applied outside, such as in vehicle radiators and outdoor air-conditioners. Sensorless controls that cannot detect rotor position requires additional sensorless control algorithm because a rotor is rotated by an external load. In this study, the sensorless control of a PM synchronous motor under naturally rotating condition is proposed. The natural rotation conditions are classified as forward high-speed rotation, reverse high-speed rotation, and low-speed rotation. Experiment results verify the performance of the sensorless control, including the rotor speed and position detection at natural rotation mode and switch to the closed-loop sensorless control.

Evaluation of Crossability, Seed Dormancy and Overwintering Ability in Glufosinate Ammonium-Resistant GM Rice and Their Hybrids with Non-GM and Weedy Rice

  • Lee, Seung-Yeob;Kim, Min-Soo;Kim, Hyo-Jin;Han, Seong-Soo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.1
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    • pp.53-58
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    • 2006
  • This study was conducted to investigate the crossability, seed dormancy and overwintering ability of rice plant in GM (glufosinate ammonium-resistant lines. Iksan 483 and Milyang 204) and non-GM (their parents) or red rice (Andongaengmi). Seed-setting rate was not significantly different between GM and non-GM rice varieties. Iksan 483 and Milyang 204 showed the similar level of seed germination rate from 30 to 50 days after heading as compared to non-GM rice varieties. After overwintering in paddy field, seed germination rate of GM and non-GM rice varieties ranged from 14.3 % to 57.6 % in dry soil condition, but there was no germination in wet-soil except red rice. The result in wet-soil condition may help to set up a strategy for reducing the risk of gene flow of transgene via dispersal of seeds of GM plants. The crossability, seed dormancy and seed overwintering of Iksan 483 and Milyang 204, herbicide resistant GM rice varieties, were not significantly different compared to non-GM rice varieties. The results might be helpful to reduce the risk of transgene dispersal from GM crop via seeds and pollens.

Growth Reaction of Some Ground Cover Plant in Korean Native Greening according to Shading Levels (몇 가지 자생 지피식물의 차광에 따른 생장반응)

  • Kim, Gui Soon;Lee, Jeong Sik
    • FLOWER RESEARCH JOURNAL
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    • v.17 no.2
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    • pp.75-80
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    • 2009
  • The objective of this research was to select the native shade tolerance plant which grows well from landscape objective of the urban. Seven species native ground cover plants were evaluated on the growth and chloropyll under 0, 40, 60, 90% shading treatments. Hosta longipes was showed the quite good growth from 60% level of natural light. The plant growth of Liriope platyphylla was good within $144.2{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ intensity which is 90% shade level of natural light. But, Dryiopteris crassirhizoma was judged with shade tolerance plant which grow quite well from shading condition level of 60% degree. Carex siderosticea was showed the highest plant length and plant width in 40% shading of natural light more than at conditon too much shading. Hosta longipes, Liriope platyphylla, Dryiopteris crassirhizoma, and Carex siderosticea were as shade tolerance plant with increases chlorophyll content well to overcome a light restrictive condition and is adapted to seem with the result.

A Study on Optimization of Diesel Combustion in condition of Premixed Natural gas (천연가스 예혼합 분위기 내 디젤 연소의 최적화에 관한 연구)

  • Suh, Hyunuk;Jeon, Chunghwan
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.141-142
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    • 2014
  • This numerical study was carried out to optimize dual fuel combustion on natural gas-diesel in static chamber. Spray experiments conducted under conditions of premixed methan 0%, 5% and 10%. In the results, penetration decreases when premixed methane is increasing. Constants of numerical models were acquired from results of spray experiments to enhance accuracy of numerical study. And dual fuel engine simulation was implemented by using AVL-FIRE with acquired constants.

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Aspect Ratio Effect of the Natural Convection in Horizontal Enclosure with an Array of Square

  • Lee J.R.;Ha M.Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2003.10a
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    • pp.286-288
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    • 2003
  • The physical model considered here is a horizontal layer of fluid heated below and cooled above with a periodic array of evenly spaced square cylinders placed at the center of the layer, whose aspect ratio here varies from unity to six. Periodic boundary condition is employed along the horizontal direction to allow for lateral freedom for the convection cells. Two-dimensional solution for unsteady natural convection is obtained using an accurate and efficient Chebyshev spectral multi-domain methodology for a given Rayleigh numbers of $10^6$

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Permeability Coefficient Properties of Mortar using Natural Inorganic Minerals (무기계 천연광물을 사용한 모르타르의 특수계수 특성)

  • Kim Sung-Bae;Park Sun-Gyu;Song Ha-Won;Byun Keun-Joo;Kim Jae-Young
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.445-448
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    • 2005
  • In this paper, waterproofing improvement of cement mortar is researched by comparing cement mixed with natural inorganic minerals with OPC under the same condition. The result shows that cement mixed with natural inorganic minerals has less permeability and absorption compared to OPC, which can be used as important data for improvements of durability and waterproofing of concrete structures.

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Comparison of Seed Germinating Vigor, Germination Speed and Germination Peak in Kentucky Bluegrass Cultivars under Different Germination Conditions (발아환경에 따른 켄터키 블루그래스의 종자 발아력, 발아세 및 발아피크 비교)

  • Kim, Kyoung-Nam
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.3
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    • pp.23-38
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    • 2015
  • The study was initiated with Kentucky bluegrass (KB, Poa pratensis L.) to investigate germination and early establishment characteristics of new cultivars for a practical application to turfgrass establishment such as parks, athletic field and golf course etc. Fifteen cultivars were evaluated in different experiments. An alternative condition for a KB germination test required by International Seed Testing Association (ISTA) was applied in Experiment I, consisting of 8-hr light at $25^{\circ}C$ and 16-hr dark at $15^{\circ}C$ (ISTA conditions). Experiment II was conducted under a room temperature condition of 5 to $25^{\circ}C$ (natural conditions). Seed germinating vigor, germination speed and germination peak time were measured in both experiments. Significant differences were observed in seed germinating vigor, germination speed and germination peak time. Seed germinating vigor was variable with different environments and cultivars. It was 75.25 to 89.50% under ISTA conditions and 75.75 to 90.25% under natural conditions. There were considerable variations in early germination characteristics among KB cultivars according to different environments. Early germination characteristics showed that all cultivars were 3 to 5 days faster in germination under ISTA conditions, when compared with natural conditions. The germination speed, measured as days to seed germination of 50% to 80%, was much faster with 'Midnight II', 'Excursion' and 'Midnight' under ISTA conditions. But it was faster with 'Midnight II', 'Excursion' and 'Odyssey' under natural conditions. Differences was also observed in germination peak time with cultivars and growing conditions. It ranged 5.94 to 14.88 days under ISTA conditions and 4.71 to 13.06 days under natural conditions. Regardless of the environment conditions, the shortest cultivars were 'Odyssey' and 'Midnight II'. The longest ones were 'Nuglade' under ISTA condition and 'Moonlight' under natural conditions. Considering germinating vigor, germination speed and germination peak time, 'Midnight II', 'Excursion', 'Midnight', and 'Odyssey' were regarded as excellent cultivars under ISTA conditions in terms of early establishment characteristics, while 'Midnight II', 'Excursion', 'Odyssey', and 'Courtyard' under natural conditions. These results suggest that an intensive germination test be needed prior to planting, for investigating the early germinating vigor, germination speed and germination peak time. Also, a proper cultivar selection and comprehensive site analysis for the growing environmental conditions should be done before turfgrass establishment such as golf course construction.

A Study on Natural Dyeing (3) - Change of physical structure and Chinese gallotannin treatment on silk fabric - (천연염색에 관한 연구 (3) - 견에 대한 Chinese gallotannin 처리 및 구조변화 -)

  • Kim, Hye In;Eom, Seong Il;Park, Su Min
    • Textile Coloration and Finishing
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    • v.13 no.5
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    • pp.1-1
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    • 2001
  • As the basic study to investigate the mechanism of improvement in the dyeing fastness of natural dyes on silk fabrics the optical behavior of tannin solution, the optimal condition of tannin treatment and the changes of the physical structure of silk fabrics were studied in the treatment of tannin. Results obtained were as follows ; 1.The K/S values of tannin-treated silk fabrics were not changed by tannin content on silk fabrics but yellowing of tannin in treatment condition. 2. As the concentration of tannin was increased in its treating condition, the tannin content and K/S vague of tannin-treated silk fabrics were increased. 3. Because tannin gave rise to yellowing by hydrolysis and oxidation at high temperature, the higher tannin-treating temperature was, the lower the tannin content and K/S values of silk fabrics 4. The tannin content of silk fabric was higher in acidic treating condition and the highest K/S value was showed at pH 5. 5. As the tannin content of silk fabric was increased, the value of ζ -potential of it became negative. 6. As the tannin content of silk fabric was increased, the crystallinity and crystallite size of it were decreased. This meant that the fraction of amorphous region in the fibers increased. And the degree of orientation of it was decreased with the tannin treatment.

A Study on Natural Dyeing (3) - Change of physical structure and Chinese gallotannin treatment on silk fabric - (천연염색에 관한 연구 (3) -견에 대한 Chinese gallotannin 처리 및 구조변화-)

  • 김혜인;엄성일;박수민
    • Textile Coloration and Finishing
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    • v.13 no.5
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    • pp.289-297
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    • 2001
  • As the basic study to investigate the mechanism of improvement in the dyeing fastness of natural dyes on silk fabrics the optical behavior of tannin solution, the optimal condition of tannin treatment and the changes of the physical structure of silk fabrics were studied in the treatment of tannin. Results obtained were as follows ; 1 The K/S values of tannin-treated silk fabrics were not changed by tannin content on silk fabrics but yellowing of tannin in treatment condition. 2. As the concentration of tannin was increased in its treating condition, the tannin content and K/S vague of tannin-treated silk fabrics were increased. 3. Because tannin gave rise to yellowing by hydrolysis and oxidation at high temperature, the higher tannin-treating temperature was, the lower the tannin content and K/S values of silk fabrics 4. The tannin content of silk fabric was higher in acidic treating condition and the highest K/S value was showed at pH 5. 5. As the tannin content of silk fabric was increased, the value of $\xi$ -potential of it became negative. 6. As the tannin content of silk fabric was increased, the crystallinity and crystallite size of it were decreased. This meant that the fraction of amorphous region in the fibers increased. And the degree of orientation of it was decreased with the tannin treatment.

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