• 제목/요약/키워드: re-expansion

검색결과 232건 처리시간 0.022초

Expression of NAC transcription factor is altered under intermittent drought stress and re-watered conditions in Hevea brasiliensis

  • Luke, Lisha P.;Sathik, M.B. Mohamed;Thomas, Molly;Kuruvilla, Linu;Sumesh, K.V.
    • Journal of Plant Biotechnology
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    • 제44권2호
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    • pp.142-148
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    • 2017
  • Drought stress is one of the important factors that restrict the expansion of Hevea brasiliensis cultivation to non-traditional regions experiencing extreme weather conditions. Plants respond to drought stress by triggering expression of several drought responsive genes including transcription factors which in turn trigger expression of various downstream signalling pathways and adaptive networks. Expression of such drought responsive genes may revert back to their original level upon re-watering. However, no reports are available on such phenomenon in Hevea and hence, this study was initiated. For this purpose, NAC transcription factor (NAC tf) was chosen as candidate gene. Its expression levels were monitored under intermittent drought as well as irrigated conditions in two clones (RRII 105 and RRIM 600) of H. brasiliensis with contrasting tolerance level. Copy number of NAC tf was found similar in both the clones. Expression of NAC tf was found highly up-regulated in RRIM 600 (a relatively drought tolerant clone) than in RRII 105 (a relatively drought susceptible clone) throughout the drought incidences which upon re-watering, reached back to its original levels in both the clones. The study indicated the existence of an association between expression of NAC tf and drought tolerance trait exhibited by the tolerant clone RRIM 600. The study also proves the influence of drought and re-watering on the leaf photosynthesis and expression of NAC tf in H. brasiliensis.

A study on Production of Al Foam by Using of Al Return Scrap for Sound and Vibration Absorption Materials

  • Hur, Bo-Young;Kim, Sang-Youl;Park, Dae-Chol;Jeon, Sung-Hwan;Park, Chan-Ho;Yoon, Ik-Sub
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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    • pp.198-201
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    • 2001
  • Porous structures of aluminum foam have been studied by using return aluminum scrap. The apparent foam shape, foam height, density, pore size and their distributions in various section areas of the experimental samples have been investigated. The sample have been cast into metallic mold, using aluminum foam prepared from a precursor based on pure Al ingot and return aluminum scrap mixed with various amounts of 1-2wt% increasing viscosity and foam agent materials. The process provides for flexibility in design of foam structures via relatively easy control over the amount of hydrogen evolution and the drainage processes which occur during foam formation. This is facilitated by manipulating parameters such as the foaming agent, thermal histories during solidification and mix melt viscosities. A metal for producing the foamed are decomposing a foaming agent in a molten metal such that there is an initial and a subsequent expansion due to foaming agent. It has been found that the Al porous foaming with variation amount of 1∼2wt% foam agent and at 2min holding time, which melting temperature has appeared homogeneous pore size at 650∼700$^{\circ}C$. The compression strength were 10-13 kg/min at 125ppi, and increased by higher pore density. The acoustical performance of the panel made with the foamed aluminum is considerably improved; its absorption coefficient shows NRC 0.6-0.8. It has been found that the Al foam is very preferable for the compactness of the thermal system.

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체외성숙, 체외수정 및 체외배양에서 생산된 소 배반포기배의 초자화 동결 (Cryopreservation of Bovine IVM/IVF/IVC Blastocysts by Vitrification)

  • 남화경;김은영;이금실;윤산현;박세필;임진호
    • Clinical and Experimental Reproductive Medicine
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    • 제26권2호
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    • pp.231-238
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    • 1999
  • 본 연구는 체외생산된 소 배반포기배를 발달 단계 및 배양일에 따라 구별하여 초자화 동결 및 융해하였을 때, 그 발달능을 유지하는지 확인하고자 실시하였다. 체외수정 후 8일간 배양된 배반포기 배는 20% ethylene glycol에 3분 동안 평형시키고, EFS40 (40% ethylene glycol, 18% ficoll, 0.3M sucrose 그리고 10% FBS가 함유된 mDPBS) 동결액에 30초 동안 노출한 후, 액체질소에 침지하여 초자화 동결되었다. 체외 생존 여부는 응해 24시간 및 48시간에 재팽창 및 탈출 또는 완전탈출로써 평가하였다. 그 결과를 요약하면 다음과 같다. 1) 체외수정 후 8일간 배 양하였을 때, 난할된 배의 배반포기 배로의 발달율은 41.0%였다 (초기 ; 7.6%, 팽창; 22.9%, 탈출; 4.6%, 완전탈출; 5.9%). 2) 배반포기배를 동결액에 노출 또는 초자화 동결하였을 때, 초자화 동결된 배반포기배의 재팽창율 (73.3%)은 대조군 및 동결액에 노출된 경우 (100, 97.0%)보다 낮았다 (p<0.05). 그러나 융해 48시간 후 탈출 또는 완전탈출 배반포기배 형성율은 초자화 동결된 경우 (66.7, 46.7%)와 노출된 경우 (66.7, 39.4%)는 유의한 차이를 나타내지 않았으나, 대조군(100, 100%)과는 차이를 보였다 (p<0.01). 그러나, 완전탈출까지 발달한 배반포기배의 총 세포수를 조사하였을 때, 각 처리군간의 유의한 차이는 없었다. 3) 배반포기배의 발달 단계에 따른 체외 생존율을 비교하였을 때, 재팽창율은 실험군간에 유의한 차이를 보이지 않았다 $(64.5{\sim}75.6%)$. 그러나 융해 48시간 후, 탈출 또는 완전탈출로써 평가된 초기 배반포기배의 발달율 (25.8, 9.7%)은 팽창 (69.7, 39.4%)및 탈출 배반포기배 (53.3, 43.3%)의 발달율보다 낮게 나타났다 (p<0.05). 4) 또한, 배양 7, 8 그리고 9일의 팽창 배반포기배를 초자화 동결하였을 때, 8일 및 9일간 배양된 배반포기배의 재팽창율은 7일간 배양된 경우보다 낮게 나타났다 (7일; 93.9%, 8일; 75.8%, 9일; 87.5%) (p<0.05). 그러나 완전탈출 배반포기배로의 발달율에서는 처리군간에 유의한 차이를 보이지 않았다 (7일; 36.4%, 8일; 36.4%, 9일; 31.3%). 이러한 결과는 EFS40을 이용한 2단계 초자화 동결 방법이 체외생산 된 팽창 및 탈출 배반포기배의 동결에 유용하게 이용될 수 있음을 시사한다.

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지적측량수행자의 업무영역 개선방안에 관한 연구 (Improvement Plans for Working Area of Cadastral Surveyors)

  • 홍성언
    • 한국산학기술학회논문지
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    • 제15권1호
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    • pp.237-242
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    • 2014
  • 본 연구에서는 지적측량수행자의 개방 업무 현황 및 실태 등을 분석하여 지적측량수행자의 업무수행 영역에 관한 개선방안을 제시하여 보고자 하였다. 연구성과는 다음과 같다. 현황 및 실태 분석된 내용을 토대로 지적측량수행자 업무영역의 개선방안으로서 지적확정측량 대상 범위의 확충, 지적확정측량업무의 참여 기준 완화 그리고 지적재조사사업에 있어 지적측량업자의 폭넓은 참여 기회 제공 방안을 제시하였다. 국토교통부에서는 지적측량수행자 업무영역의 개선방안에 대해 다방면으로 합리적이고 현실적인 지적측량시장 여건을 조성할 수 있도록 입법정책적 개선을 시도한다면 지적측량수행자간의 공생적 발전을 이룰 것이다.

무기폐(無氣肺)가 폐표면활성도(肺表面活性度)에 미치는 영향에 관(關)한 실험적(實驗的) 연구(硏究) (Effects of Atelectasis on Surface Activity of lung in Rabbits)

  • 우종수;조광현;김종원;손말현;신근수;김진식
    • Journal of Chest Surgery
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    • 제9권2호
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    • pp.109-116
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    • 1976
  • The effects of atelectasis on surface activity of lung extracts were examined in rabbits. Experimental atelectasis was produced in rabbits by artificial pneumothorax and surface tension properties were measured on saline extracts of lung 24 hrs, 48 hrs, one week and four weeks after the induction of pneumothorax. The results were as follows; 1) The minimum surface tension of excised lung extracts 24 hrs after pneumothorax was significantly increased to 28.3 0.41 dynes/cm, and the stability index was significantly decreased to 0.30 from normal value of 0. 87. 2) In the group which was re-expanded 24 hours, later from pneumothorax the surface activity was returned to almost normal range 24 hrs after reexpansion of collapsed lung, 3) When the atelectasis was continued by mechanical means, the extracts of atelectatic lung showed progressive decrease in surface activity, but it was found that surface activity returned to normal level after four weeks even the presence of atelectasis. 4) These observations suggest to us that atelectasis per se does not cause an increase in surface tension of lung extracts, and even in prolonged atelectasis the re-expansion of collapsed lung may be possible when the mechanical cause of atelectasis was excluded.

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A Facial Chuna Manual Therapy for Peripheral Facial Nerve Palsy

  • Park, Yu-Kyeong;Lee, Cho In;Lee, Jung Hee;Lee, Hyun-Jong;Lee, Yun-kyu;Seo, Jung-Chul;Kim, Jae Soo
    • Journal of Acupuncture Research
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    • 제36권4호
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    • pp.197-203
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    • 2019
  • The purpose of this study was to investigate useful manual therapy techniques for peripheral facial nerve palsy and to propose guidelines to be applied for current manual therapy techniques. Several databases were searched to find manual therapies for facial palsy. These therapies included cervical, and temporomandibular joint chuna manual therapy, proprioceptive neuromuscular facilitation, neuromuscular re-education, facial exercise, and mime therapy. Both cervical, and temporomandibular joint chuna manual therapy release nerve compression, helping blood circulation and nerve conduction. Proprioceptive neuromuscular facilitation uses irradiation, bilateral activation, and eccentric facilitation to improve muscle power and symmetry. Neuromuscular re-education, as a retraining tool for facial movement patterns, enhances neuromuscular feedback. Facial exercise helps the patient continuously move and massage facial muscle themselves. Mime therapy aims to develop a conscious connection between the use of certain muscles and facial expressions. The use of facial chuna manual therapy for peripheral facial nerve palsy can stimulate the proprioceptive neuromuscular receptors in the face. Peripheral facial nerve palsy has 4 phases; progress phase, plateau phase, recovery phase, and sequelae phase. Each phase needs different treatments which include relaxation, assistance, resistance, origin-insertion extension, and nerve pathway expansion.

Numerical Simulation of the Water Temperature in the Al-Zour Area of Kuwait

  • Lee, Myung Eun;Kim, Gunwoo
    • 해양환경안전학회지
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    • 제25권3호
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    • pp.334-343
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    • 2019
  • The Al-Zour coastal area, located in southern Kuwait, is a region of concentrated industrial water use, seawater intake, and the outfall of existing power plants. The Al-Zour LNG import facility project is ongoing and there are two issues regarding the seawater temperature in this area that must be considered: variations in water temperature under local meteorology and an increase in water temperature due to the expansion of the thermal discharge of expanded power plant. MIKE 3 model was applied to simulate the water temperature from June to July, based on re-analysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and the thermal discharge input from adjacent power plants. The annual water temperatures of two candidate locations of the seawater intake for the Al-Zour LNG re-gasification facility were measured in 2017 and compared to the numerical results. It was determined that the daily seawater temperature is mainly affected by thermal plume dispersion oscillating with the phase of the tidal currents. The regional meteorological conditions such as air temperature and tidal currents, also contributed a great deal to the prediction of seawater temperature.

DIFFUSIVE SHOCK ACCELERATION BY MULTIPLE WEAK SHOCKS

  • Kang, Hyesung
    • 천문학회지
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    • 제54권3호
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    • pp.103-112
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    • 2021
  • The intracluster medium (ICM) is expected to experience on average about three passages of weak shocks with low sonic Mach numbers, M ≲ 3, during the formation of galaxy clusters. Both protons and electrons could be accelerated to become high energy cosmic rays (CRs) at such ICM shocks via diffusive shock acceleration (DSA). We examine the effects of DSA by multiple shocks on the spectrum of accelerated CRs by including in situ injection/acceleration at each shock, followed by repeated re-acceleration at successive shocks in the test-particle regime. For simplicity, the accelerated particles are assumed to undergo adiabatic decompression without energy loss and escape from the system, before they encounter subsequent shocks. We show that in general the CR spectrum is flattened by multiple shock passages, compared to a single episode of DSA, and that the acceleration efficiency increases with successive shock passages. However, the decompression due to the expansion of shocks into the cluster outskirts may reduce the amplification and flattening of the CR spectrum by multiple shock passages. The final CR spectrum behind the last shock is determined by the accumulated effects of repeated re-acceleration by all previous shocks, but it is relatively insensitive to the ordering of the shock Mach numbers. Thus multiple passages of shocks may cause the slope of the CR spectrum to deviate from the canonical DSA power-law slope of the current shock.

한국춤의 색과 공간에서의 문화철학적 표상에 관한 이미지 재고 (Rethinking images of Korean dance Colors and Cultural Philosophical Representations in Space)

  • 김지원
    • 공연문화연구
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    • 제41호
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    • pp.157-186
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    • 2020
  • 한국춤의 표상을 색채라는 의미에서 조명한다. 한국춤의 고유한 색과 빛은 한국예술의 정수이자 한국인의 의식을 투영한다. 그러므로 한국예술, 색과 의미를 분석한다는 것은 한국의 색을 재조명할 수 있는 미학적 해석의 원리를 제공할 수 있다. 이는 한국예술의 근원을 묻고 인문학적 기반으로서 독창적 콘텐츠의 개발 가능성에 주목해야 함을 뜻한다. 색과 삶, 그것이 문화가 되는 한국적 사상과 철학은 한국 예술의 또 다른 재창조적 시야를 위한 뿌리로 남는다. 따라서 한국춤을 인식하는 여러 가지 미적 태도는 다양한 해석의 확대와 함께 예술로서 한국적 정체성의 체계를 확립하는 것이 필요한 때이다.

SiAlON Bulk Glasses and Their Role in Silicon Nitride Grain Boundaries: Composition-Structure-Property Relationships

  • Hampshire, Stuart;Pomeroy, Michael J.
    • 한국세라믹학회지
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    • 제49권4호
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    • pp.301-307
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    • 2012
  • SiAlON glasses are silicates or alumino-silicates, containing Mg, Ca, Y or rare earth (RE) ions as modifiers, in which nitrogen atoms substitute for oxygen atoms in the glass network. These glasses are found as intergranular films and at triple point junctions in silicon nitride ceramics and these grain boundary phases affect their fracture behaviour. This paper provides an overview of the preparation of M-SiAlON glasses and outlines the effects of composition on properties. As nitrogen substitutes for oxygen in SiAlON glasses, increases are observed in glass transition temperatures, viscosities, elastic moduli and microhardness. These property changes are compared with known effects of grain boundary glass chemistry in silicon nitride ceramics. Oxide sintering additives provide conditions for liquid phase sintering, reacting with surface silica on the $Si_3N_4$ particles and some of the nitride to form SiAlON liquid phases which on cooling remain as intergranular glasses. Thermal expansion mismatch between the grain boundary glass and the silicon nitride causes residual stresses in the material which can be determined from bulk SiAlON glass properties. The tensile residual stresses in the glass phase increase with increasing Y:Al ratio and this correlates with increasing fracture toughness as a result of easier debonding at the glass/${\beta}-Si_3N_4$ interface.