• Journal of Photoscience
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• 제5권1호
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• pp.17-22
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• 1998

Changes of chlorophyll fluorescence and xanthophyll cycle pigment contents in maize leaves were investigated dunng desiccation in darkness or in the light. In darkness, a drastic dehydration of detached maize leaves down to 50% relative water content (RWC) affected photochemical efficiency of photosystem II (Fv/Fm) and pht)tochemical quenching (qP) only slightly. In contrast, desiccation in the light with a moderate intensity led to a pronounced reduction in Fv/Fm with a Fo quenching when RWC was greater than 70%. This reduction in Fv/Fm could be recovered in darkness under hutrod condition. In leaves with RWC below 70%, significant reduction in Fv/Fm was accompanied by an increase of Fo, which could not be reversed within 5 h in darkness under humid condition. The nonphotochemical quenching increased during desiccation in the light with a concomitant rise in zeaxanthin at the expense of violaxanthin. Pretreatment with dithiothreitol (DTT), an inhibitor of zeaxanthin synthesis, inhibited the development of nonphotochemical quenching and prevented the xanthophyll interconversion during desiccation in the light. These results suggest that even light with a moderate intensity becomes excessive under dehydration and zeaxanthin-associated photoprotection of photosynthetic apparatus against photodamage is involved, but the protection is not complete against severe desiccation.

• 한국지반공학회논문집
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• 제15권6호
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• pp.219-238
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• 1999

본 연구에서는 연약한 점토층 준설매립지반을 대상으로, 비교적 활발히 연구가 진행되고 있는 자중압밀 침하분야에 비해 상대적으로 연구성과가 미흡한 표토층의 건조수축특성 규명에 초점을 두고, 침투압밀시험, 부압시험 및 건조수축시험 등 실내시험을 시행하였다. 실내시험이 시행된 시료는 전라남도에 위치한 해남지구, 고금지구 및 고흥지구 등 3개 지구의 현장시료이며, 실내시험결과를 토대로 건조수축 관련특성을 분석하였다. 또한 Abu-Hejleh % Znidarcic가 제안한 연약한 세립점토 지반의 건조수축 침하이론 지배방정식을 유한차분형태로 표현하고 실내시험을 통해 파악된 해남지구 현장시료의 건조수축특성 등을 입력자료로 하여, 3차원 체적변화에 따른 건조수축침하를 수치적으로 예측하였다. 계속해서 자중압밀침하를 포함한 전체침하 예측치를 해남지구 현장에서의 10년간 실제 관측결과와 서로 비교하였다. 최종적으로는 건조수축특성에 관련된 변수들이 침하 등에 미치는 영향정도를 분석하였다. 특성 (불연속면의 방향 및 강도), 하중조건 및 암반사면의 기하학적 형상 등이다. 확률론적 해석에서 고려할 수 있는 불연속면의 방향 및 마찰각의 통계적 특성이 파괴형태를 고려한 암반사면의 안정에 큰 영향을 보였다. 암반사면의 안정은 굴착면의 방향에 가장 민감하였다. 예제분석을 통하여 개발된 파괴형태를 고려한 암반사면의 신뢰도모델은 암반사면의 안정성 조사에 성공적으로 적용할 수 있었다.

• Ocean and Polar Research
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• 제42권3호
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• pp.225-231
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• 2020

The aim of this study was to examine optimal induction method for carpospore release from Agarophyton vermiculophyllum cystocarps for seedling production. We tested the effects of environmental factors on carpospore release by using five different induction methods; spontaneous, desiccation, low temperature, desiccation+low temperature, and osmotic shock. Also, carpospores release was estimated at three temperatures (20, 25, and 30℃), and then under combinations of three day lengths (8, 12, and 16h) and two irradiances (30 and 60 μmol photons m^-2 s^-1), after pretreatment at desiccation+low temperature for 2 hr. The number of carpospores released was between 113 ~ 682 spores /cystocarp/day and it was maximal in the desiccation+low temperature treatment. Optimal environmental conditions for carpospore release of A. vermiculophyllum were 25℃, 16 h, and 60 μmol photons m^-2 s^-1. The present results suggest that massive carpospores for seedling production of A. vermiculophyllum could be obtained under a combination of 25℃, 16 h, and 60 μmol photons m^-2 s^-1 after pretreatment in the desiccation+low temperature.

• 한국작물학회지
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• 제48권1호
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• pp.13-16
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• 2003

Seeds of burcucumber were treated with accelerated aging, cold-stratification, and light quality illuminated during desiccation to enhance their germination and seedling emergence. The germination was increased by aging and cold-stratification although the latter treatment showed greater effectiveness than the former one. In the combined treatment of aging 6 days at $45^{\circ}C$ and cold-stratification, the germination was promoted under longer period of cold-stratification to reach nearly 100% in 3 week cold-stratification on the ninth day from sowing. In the sequentially combined treatment of aging, cold-stratification, and light quality during 24 hour desiccation at $35^{\circ}C$, no-stratified seeds showed the highest rate in red light treatment but the lowest in far-red light. This implies that the phytochrome action run during the desiccation of imbibed seeds. The red light exposure during drying for the cold-stratified seeds after aging accelerated the germination even more than the dark treatment and germinated 100% on the next day of sowing. It is concluded that the sequential treatment of aging, cold-stratification, and red light illumination during desiccation can highly promote percentage and speed of burcucumber seed germination.

• 생물환경조절학회지
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• 제15권1호
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• pp.100-106
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• 2006

A hypertonic solution of sorbitol was used to precondition Douglas-fir and Western hemlock plug seedlings to improve desiccation resistance. Seedlings were preconditioned by soaking their root balls in water, -0.75 or -1.50 MPa sorbitol solution for 22 hr, and then exposed to desiccation conditions for 8 days. During the desiccation period, a transpirational water loss was significantly reduced by the sorbitol preconditioning, with its effect positively depending on concentration. This preconditioning-induced reduction in water loss was mainly caused by the decline in needle stomatal conductance. Sorbitol-induced stomatal control was more closely associated with reduction in plant water potential, rather than increase in abscisic acid concentrations. After rehydration of stressed-plants, most of the preconditioned seedlings with sorbitol were survived, while only 35% of Douglas-fir and 28% of Western hemlock seedlings treated with water were alive. The post-growth was significantly greater in the preconditioned seedlings than only water-treated seedlings. These results suggested that the earlier stomatal control with sorbitol-facilitated preconditioning could play a role in improving desiccation resistance of evergreen woody plants at transplanting in the field where water supply is limited or dry conditions are prevailing.

• Corrosion Science and Technology
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• 제15권4호
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• pp.166-170
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• 2016

The combined process of porous type anodizing and desiccation treatment was applied to improve wettability of A1050 aluminum alloy. The water contact angles of anodized samples were increaseds considerably with desiccation treatment. However, there was no considerable effect of polishing and anodizing time on water contact angle. The corrosion behavior with the treatments was investigated electrochemically. The corrosion resistance of the samples in 3.5 mass% NaCl solutions increased with higher contact angle. Anodized and desiccated samples showed better corrosion resistance than un-desiccated samples around rest potential region.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 가을 학술발표회 논문집
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• pp.529-536
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• 2002

The purpose of this paper os to present and discuss some of flow and drain observed in modelling results. Because dredged fill ground of Yul-Chon located in the south coast of Korea is very soft, this ground should be improved after operation of surface stabilization. There are surface stabilization method such as chemical stabilization, desiccation, horizontally vacuum drain, replacement, and geosynthetics. In Yul-Chon, PTM(Progressive Trenching Method) is adopted to provide the necessity condition of surface desiccation. In the case trench in the dredged soft ground is formed by PTM equipment, pore water in the ground is drained through trench. There, drain and desiccation of surface ground increase, and bearing capacity is improved. In this research, when trench in the dredged soft ground is formed by PTM equipment, permeable characteristics and drain efficiency of pore-water are analyzed using SEEP/W software package. Results show variation of total head, pressure head, flux, hydraulic gradient, and flow quantity.

• The Korean Journal of Pain
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• 제34권4호
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• pp.447-453
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• 2021

Background: Provocative discography (PD) is a test that is useful in diagnosing discogenic pain (DP). In this study, to diagnose DP, we used a posterolateral approach of needle placement and followed pressure criteria laid down by the Spine Intervention Society. The aim was to identify the correlation between magnetic resonance imaging (MRI) findings (desiccation, high intensity zone and change in shape and size of the disc) and the results of PD. Methods: Records of 50 patients who underwent PD for DP were analyzed. A total of 109 PDs were performed, with 54 suspect and 55 control discs. Alternate pain generators were ruled out. Results: A total of 35 suspect discs were positive on PD. The mean disc pressure in the suspect disc was 31.9 ± 7.9 psi (range, 15-44). Of the 50 patients who underwent PD, 35 had positive MRI findings. A significant positive correlation was found only between disc desiccation and discography result (r = 0.6, P < 0.001). Logistic regression analysis revealed that only desiccation successfully predicted the result of discography (OR = 26.5, P < 0.001); a high intensity zone and a disc protrusion/extrusion had an OR 2.3 and 1.24, respectively. Disc desiccation of Pfirmann grade 3 or more had a sensitivity and specificity of 0.93 and 0.64 respectively in identifying painful discs; the positive likelihood ratio was 2.58 while the negative likelihood ratio was 0.11. Conclusions: In patients with DP, disc desiccation is the most useful MRI feature that predicts a painful disc on PD.

• 한국해양학회지:바다
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• 제22권3호
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• pp.69-76
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• 2017

거머리말은 해양 현화 식물로 일생의 대부분을 해수 내에서 생활하며, 공기에 노출시 건조 스트레스를 받게 된다. 지금까지 거머리말 성체에서 나타나는 건조 스트레스는 다수 알려진데 비해, 거머리말 종자의 건조 스트레스에 대한 정보는 부족한 편이다. 이 연구는 거머리말 종자의 건조 스트레스를 알아보기 위해 공기 중 노출로 인한 종자의 발아율과 함수율의 변화를 실험하였다. 상대습도 50%, $20^{\circ}C$의 공기에 1시간 노출된 거머리말 종자의 발아율은 현저히 감소되었으며, 노출시간이 길어질수록 종자의 발아율은 지속적으로 감소하였고, 11시간 이상 노출된 종자는 전혀 발아하지 않았다. 거머리말 종자의 공기 노출시간이 길어질수록 발아율과 함수율은 감소하는 음의 상관관계가 나타났다. 또한, $30^{\circ}C$의 공기에 노출된 거머리말 종자는 $10^{\circ}C$와 $20^{\circ}C$의 공기에 노출된 거머리말 종자보다 현저히 낮은 발아율을 나타내었다. 따라서 거머리말 성체가 공기 중 노출 시 건조 스트레스를 겪는 것처럼 거머리말 종자도 건조에 의한 발아율의 감소가 확인되었으며, 이것은 종자를 활용한 거머리말 서식지 복원 사업에 유용한 정보를 제공하고자 한다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2020년도 춘계학술대회
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• pp.15-15
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• 2020