• 지질공학
• /
• 제32권3호
• /
• pp.401-410
• /
• 2022

본연구에서는 순수한 흙입자의 무게를 측정하는 유효한 방법을 찾기 위하여 예천지역의 화강풍화토를 대상으로 노건조 시험을 수행하였다. 노건조 후 데시케이터를 사용하는 한국산업표준(KS F)에 규정된 방법과 데시케이터를 사용하지 않는 경우에 대하여 비교하였다. 노건조 후 45분간 공기 중에 노출된 흙시료는 공기 중에서 수분을 흡수하여 무게가 점진적으로 증가하였다. 공기 중에 노출 후 30초에 측정된 결과에서 데시케이터를 사용한 경우는 데시케이터를 사용하지 않은 경우에 비하여 흙의 입경에 따라 0.103~0.735%의 무게가 증가되었다. 노건조 후 데시케이터를 사용하면 순수한 흙무게를 과대평가하는 결과가 나타난다. 그러므로, 데시케이터의 사용 없이 노건조 후 시료의 무게를 곧바로 측정하면 흙무게의 측정오차를 감소시킬 수 있다.

• ALGAE
• /
• 제26권2호
• /
• pp.193-200
• /
• 2011

The stress tolerance ability of Pelvetia canaliculata (L.) Dcne. Et Thur. and Fucus spiralis L. to temporary and periodic emersion stress was examined in order to test the following hypotheses: The upper shore alga, P. canaliculata is more tolerant to desiccation than F. spiralis in the germling stage and the former outgrows the latter under desiccation stress; Germling stress tolerance of the two species is age-specific; Crowding of germlings protects them from desiccation, irrespective of the species involved. Germling growth of the two species was retarded with increasing exposure period and was age-specific, as they were air-exposed at an earlier stage. After 16 days, the length of Pelvetia germlings was similar between 2-day-old germlings (125-140 ${\mu}m$) and 7-day-old germlings (134-140 ${\mu}m$), which were air-exposed during the same period (0, 6, 12, 24, 48, and 72 h) at the two different ages. However, Fucus germlings were significantly larger at 7-day-old germlings (211-277 ${\mu}m$) than at 2-day-old germlings (184-278 ${\mu}m$), especially in the treatments of 48 and 72 h. These results indicate that Fuscus grow faster than Pelvetia and that the growth response of germlings to temporary emersion stress is more sensitive in Fucus than that in Pelvetia. Growth of germlings of both species was reduced with increasing density under favorable growth conditions (submerged control and 6 h / 12 h exposure treatments) in the periodic air-exposed experiments using tidal tanks, but was enhanced under severe emersion stress conditions. P. canaliculata showed better growth at 6 h exposure treatment than that of the control, under continuous submergence, indicating that Pelvetia germlings require a periodic exposure period. Fucus germlings always grew faster than those of Pelvetia and did best in mixed cultures, whereas Pelvetia did least well when mixed with Fucus germlings. The adverse effects of F. spiralis on P. canaliculata were greater than those of Pelvetia cohorts. The outcome of interspecific competition between F. spiralis and P. canaliculata gemlings was slightly altered by exposure period but not to such an extent as to change the outcome.

• 아시안잔디학회지
• /
• 제25권2호
• /
• pp.133-137
• /
• 2011

동절기 피해는 겨울철에 나타나는 피해의 형태로 유형에 따라 저온피해, 건조피해, 관부수화, 그리고 동절기 병 발생등이 있다. 저온피해는 대기온도와 토양온도에 의해 그 피해가 발생하는데 토양온도가 관부의 생육에 더 큰 영향을 미치기 때문에 그 피해의 정도가 더 심하게 발생한다. 관부수화는 세포내결빙에 의해 발생하는 피해로 세포막을 파괴하며 결과적으로 세포내 조직을 탈수시키게 된다. 저온건조는 동절기 기간동안 식물체의 잎 혹은 식물전체에 건조로 인한 피해가 나타나 고사에 이르게 되는 피해를 말한다. 동절기 피해를 예방하기 위해 가을철 인산과 칼륨의 시비가 동절기 피해에 대한 내성을 증진시키는 역할을 하게 된다. 또한 피복재의 사용이 동절기 피해를 최소화 하는 기능을 하는데 그 종류는 여러가지가 있으며 겨울철 잔디위에 쌓인 눈도 대기온도로부터 토양온도를 유지하는 피복재 역할을 하게 된다. 동절기 피해를 최소화 하기 위한 방법으로 통기와 배토의 방법이 있다. 통기와 배토는 모두 주로 대취층의 두께를 줄이기 위한 방법으로 사용이 되고 또한 겨울철 배토를 위해 사용되는 검은색 모래는 토양에 잔존해 있는 얼음을 녹이고 토양온도를 유지해주는 역할을 하게 되므로 피복재와 같이 동절기 피해를 최소화 하는 역할을 하게 된다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 1989년도 춘계 학술대회지
• /
• pp.60-61
• /
• 1989

• 한국식물생명공학회:학술대회논문집
• /
• 한국식물생명공학회 2004년도 춘계학술대회
• /
• pp.64-64
• /
• 2004

• Journal of Korean Biological Nursing Science
• /
• 제13권1호
• /
• pp.8-15
• /
• 2011

Purpose: The purpose of this study was to analyze effects of hand drying methods after hand-washing. Hand drying methods consisted of spontaneous evaporation, paper towel, hand dryer with rubbing, and hand dryer without rubbing. Methods: The research design was a crossover design. The subjects were eighteen university students and randomly assigned in four group. Each group had the schedule of treatment. The schedule tested one drying method per a day and proceeded for 4 days. The data collection was performed from July 27 to July 30, 2010. Data were analyzed by Kruskal-Wallis, Mann-Whitney and Wilcoxon test. Results: There was significant difference between the after CFU between natural dry, paper towel, air dryer with hand rubbing, and air dryer without hand rubbing(p=.006). The after CFUs of paper towel, natural dry and air dryer without hand rubbing groups were statistically less than air dryer with hand rubbing group. Conclusion: It was shown that the paper towel, spontaneous evaporation and without rubbing hand dryer are effective hand drying interventions on reducing CFU on hand. However additional researches with large sample and strict methodology are needed.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2005년도 춘계 학술발표회 논문집
• /
• pp.1412-1419
• /
• 2005

Preventing the infiltration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Compacted clay layer or geomembrain have been used as a conventional landfill final cover. But they have several disadvantages when damages might occur due to puncturing, differential settlement and desiccation or freeze and thaw. For this reason, as an alternative method SRSL(Self Recovering Sustainable Liner) has been developed. Adopting the precipitation reaction of two chemical material, by forming precipitates that fill the pores, and lower the overall permeability of the liner. The advantage of this method is that when fracture of the liner occurs the remaining reactants of the two layers form precipitates that fill the fracture and recover the low permeability of the liner. In this study, the recovering ability of the SRSL with a crack due to the seasonal variation or differential settlements was investigated by permeability tests. And in order to estimate the durability of the SRSL after freeze/thaw and desiccation, uniaxial compression strength tests were performed.

• Journal of Plant Biotechnology
• /
• 제3권2호
• /
• pp.101-106
• /
• 2001

In order to establish efficient plant regeneration from embryogenic suspension cultures of soybean, Glycine max L, we examined the effects of auxin type and concentration, cytokinin type and concentration, and amino acid type and concentration on the growth of embryogenic clumps from induced callus, and the effect of desiccation of mature somatic embryos obtained from these clumps on the frequency of somatic embryo germination. Embryogenic callus was induced from the edge of the cotyledons cultured on MS medium containing 6% sucrose, 40 mg/L 2,4-D, 0.2% gelrite and pH 5.7. The growth of embryogenic clumps was best in early staged, embryogenic callus that was placed in suspension culture of MS medium containing 5 mg/L 2,4-D and 0.5 mg/L asparagine. Single somatic embryos were isolated from the clumps and plated on the same medium for maturation. When the mature single somatic embryos were desiccated for 96 h, somatic embryo germination came up to approximately 90%. The plantlets germinated after embryos desiccation for 2 weeks were transfered to MS medium containing 3% sucrose,0.2% gelrite and pH 5.7.

• 한국지형학회지
• /
• 제19권2호
• /
• pp.145-159
• /
• 2012

화성 Mawrth Vallis지역의 점토광물을 함유한 층에서 관찰되는 파쇄 패턴의 성인을 파악하기 위해 HiRISE 영상데이터를 활용하여 분석하였다. 함유된 점토광물의 종류에 따라 지표에서 관찰되는 파쇄 패턴에 차이가 나타나는데 논트로나이트를 주로 함유한 지표의 경우 파쇄 패턴이 불규칙적이고 침식을 심하게 받은 상태이나, 몬모릴로나이트를 주로 함유한 층의 지표에는 크기와 형태가 비교적 일관성을 가지는 폴리곤 패턴이 잘 발달되어있다. 이들 폴리곤 파쇄 패턴의 성질은 점토광물 함유층에 따라 달리 해석되는데, 논트로나이트 함유층의 경우 대부분 하중 제거로 인해 발생한 것으로 보이며, 몬모릴로나이트 함유층의 지표에 발달한 파쇄 패턴은 건조 균열로 인해 발생한 것으로 추정된다.

• Journal of Forest and Environmental Science
• /
• 제36권4호
• /
• pp.267-273
• /
• 2020

Diospyros mespiliformis is a highly valued and threatened tree species within the Sahelo-Sudanian zone of Africa, but its seed germination requirements under cultivation are not well researched. In a first experiment which aimed at determining germination response of seeds to dehydration, fresh seeds were dried at room temperature for 26 days during which their moisture content, their germinability, and their viability were monitored at two-day intervals. In the second experiment, 14 pre-germination treatments were tested for their effect on the germination of dried seeds. Results showed that fresh seeds had 52.7% moisture and achieved 97.7% germination. As seeds were dried, percentage germination gradually decreased with decreasing moisture content and reached 0% when moisture content had dropped to 18%. Meanwhile, seed viability remained at 100% over drying duration. Seeds that were not germinated after air dry also recorded 100% viability. The most effective treatment for inducing germination of dried seeds was scarification using 98% sulfuric acid for 30 min which resulted in 96.6% germination. This study reports for the first time in D. mespiliformis seeds a desiccation-induced dormancy which can be efficiently alleviated by acid scarification. This study provides useful information that will contribute to efficient management of D. mespiliformis seed resources for propagation.