• Korean Journal of Plant Resources
• /
• v.28 no.2
• /
• pp.253-258
• /
• 2015

In South Korea, Pinus pumila (Pall.) Regel (dwarf stone pine) has been designated as a critically endangered species by the Korea Forest Service. We have difficulties in obtaining the seeds of P. pumila because P. pumila grows only in the Daecheongbong area (1550–1700 m above sea level) of Mt. Seorak and almost all of its cones are damaged by birds and rodents. For establishing an ex situ conservation stand of P. pumila, this study was conducted to figure out the effects of wet cold (cold stratification, prechilling) and GA₃ treatment on the germination of P. pumila seeds. After cold stratification (1, 2, 3, 4, 5 months), prechilling (1, 2, 3, 4, 5 months) and GA₃ treatment (0, 100, 500, 1,000, 2,000, 3,000 ㎎/L), seeds were placed on petri-dishes at 25℃ under light condition. The percentage of germination, mean germination time and the germination rate were investigated. The results showed that both of the cold stratification and prechilling were effective in improving germination performances. However, there were no significant differences in performances between the two cold treatments. Within each treatment, the germination performances improved with the period of treatment. However, after three months of treatment, the performances showed no significant improvement. The gibberellin treatment was also effective in improving seed germination of P. pumila. The percentage of germination reached 79.0% in the seeds treated with 100 ㎎/L of GA₃. However, the germination performances decreased at high concentration of GA₃ treatments (over 2000 ㎎/L). In conclusion, cold stratification (over 3 months) or 100 ㎎/L of GA₃ treatment was considered to be the appropriate method for seedling production of P. pumila.

• Natural Product Sciences
• /
• v.9 no.1
• /
• pp.1-3
• /
• 2003

Hemidesmus indicus var. indicus belonging to the family Asclepiadaceae was screened for its activity against Helicobacter pylori(Hp) human isolates. Flowering and vegetative period samples were analysed. Aqueous (hot and cold) and solvent extracts (acetone, chloroform and methanol) were screened. Among them chloroform extract was observed to recover bioactive principles with low MIC and MLC. MIC was $75\;{\mu}g$ in both seasons and MLC was $100\;{\mu}g$ for vegetative and $75\;{\mu}g$ for flowering periods respectively. Extracts from samples collected during flowering period was better than that of vegetative period.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1998.06a
• /
• pp.535-537
• /
• 1998

In this paper, we devised a pulse rate detection system to provide basic clinical index of cold-hot diagnosis of oriental medicine. The system consists of pulse signal detection, respiration signal detection, electrocardiograph detection, A/D conversion and computer system parts. We define a pulse rate by a pulse count to the respiration period inspiration pulse rate by a pulse count to the inspiration period, and expiration pulse rate by a pulse count to the expiration period. The clinical experiments for normal Person to evaluate the pulse rate detection system show the pulse/respiration ratio of 4.30${\pm}$1.03, the pulse/inspiration ratio of 1.60${\pm}$0.32, the pulse/expiration ratio of 2.37${\pm}$0.75.

• Asian-Australasian Journal of Animal Sciences
• /
• v.11 no.3
• /
• pp.265-267
• /
• 1998

Cattle in Alaska seemed to be tolerant to low blood selenium (Se) although arctic winter energy demands might exacerbate oxidative damage to tissues lacking protection by Se. The thermogenic properities of brown adipose tissue (BAT) and the long cold adaptation period for Alaskan cattle indicates that they might develop BAT. Eighteen mature beef cows with whole blood Se of< 19 ppb were used to examine possible relation-ships among Se deficiency, tissue lesions, and observable BAT. All cows were wintered on a diet low in Se and nine cows were given supplemental Se provided by intraruminal bolus. Blood Se was elevated (p < .05) from November through February by supplemental Se, but body weight and back fat thickness were unaffected (p < .10). Tissues were taken from two Se deficient cows, two cows supplemented with Se, and two cows given large doses of Se (300 mg by injection) four weeks before slaughter. Histopathological examination of 187 samples of fat (7 to 55 from each cow) showed no observable amount of BAT. Examination of other tissues showed no lesions attributable to Se deficiency.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05a
• /
• pp.618-621
• /
• 2006

This paper is to investigate temperature history of cold weather concrete depending on insulation curing sheet kinds. Insulating effect according to curing sheet is shown in order of 5 layer bubble sheet, combination of PE form and 3 layer bubble sheet and 3 layer bubble sheet. It maintained above $10^{\circ}C$ of minimum temperature until the completion of initial curing period when bubble curing sheet was supplied regardless of curing sheet kinds. Five layer bubble curing sheet secure higher curing temperature than any other curing sheet applied in this experiment by as much as $2{\sim}3^{\circ}C$, which performed remarkable insulation effect. Concrete applied with curing sheet secured above $65^{\circ}D{\cdot}D$ of maturity, at which concrete had 5MPa of compressive strength at 3 days.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1996.04a
• /
• pp.95-100
• /
• 1996

This paper presents the experimental study on hardening process of high-strength and high-flowable concrete. The experiments were performed to investigate any unfavorable construction situations since the actual concrete placement has been scheduled in cold weather period, so that the high quality concrete construction is convinced to be successfully carried out. The tests were conducted using 600nm and 1000nm height of steel tube to simulate the practical concrete filled steel tube columns according to the following variables as: the categories of chemical admixtures, curing temperatures and curing schemes. The test results were analyzed in terms of hardening speed, internal heat of hydration and history of strength gain. This paper emphasizes the importance of curing schemes on durability and the use of hardening accelerators on strength gain.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.2
• /
• pp.141-144
• /
• 1990

Seasonal change in the reproductive pattern of the marine Cladoceran Podon polyphemoides, was studied using materials collected monthly during the period from January to December 1986 in Yongil Bay, Korea. The relative abundance of P. polyphemoides exceeded $10\%$ of total zooplankton in July. While the species remained as a minor components of the zooplankton community during the other periods of occurrence from June to December. Occurrence of sexual individuals of P. polyphemoides (males and gamogenetic females) in higher proportion in cold months ($30\%$ in November and $40\%$ in December) suggests that resting egg production of this species is largely confined to cold monthis in Korean waters as an overwintering strategy.

• Ocean and Polar Research
• /
• v.31 no.3
• /
• pp.239-246
• /
• 2009

Long-term observations were conducted between 1997 and 2002 to examine the variability of the vertical temperature structure in the Youngsan Estuary, southwest Korea, in summer. The observed hydrographic data revealed that the temperature minimum layer in the middle depth persisted through the entire summer of 2000 but was rarely observed in other years. The variability in the vertical structure might be affected by the air temperature during the previous winter and the density difference between the open sea and the estuary. In 2000, the air temperature in the previous winter was lowest and the horizontal density difference during summer was largest. The large horizontal density difference probably produced more active driving of warm water along the bottom, which would have intruded into the Youngsan Estuary. Furthermore, the cold previous winter would have provided a better condition for maintaining cold temperatures in the middle water layer for a longer period.

• Journal of Chest Surgery
• /
• v.21 no.2
• /
• pp.231-239
• /
• 1988

Currently numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operation. During cardiac ischemia after crystalloid cardioplegia[4C GIK solution], topical cold saline[Group I, a=9], topical ice slush[Group II, n=9] and topical ice chip[Group III, a=10] have been compared for myocardial surface cooling in the isolated rat heart model of cardiopulmonary bypass. During postischemic period, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure and heart rate], biochemical enzymatic activities and cellular injuries with electron microscope were evaluated in this isolated rat heart perfusion model. Postischemic aortic flow, cardiac output and peak aortic pressure in Group I and Group II recovered better than Group III.[p< 0.05] Postischemic creatine kinase and lactate dehydrogenase leakages in Group II and Group III increased more than Group l and postischemic mitochondrial swelling in Group III was more severe than Group I, and Group II.[p< 0.05] These results suggest that topical cold saline was the better method than topical ice slush or topical ice chip as a myocardial preservation modality in the isolated rat heart model of cardiopulmonary bypass.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.9 no.6
• /
• pp.103-111
• /
• 2001

During cold-start period, the reduction of exhaust emissions is a challenging task. To decrease harmful gaseous substances such as HC, it is necessary to realize a fast catalyst warm-up. In this study, the performance of dual pipe exhaust system have been carried out through different test mode. From measurement of gas temperature and HC concentration, the following conclusions were derived ; 1) Compared with single pipe, dual pipe exhaust system remarkably increase temperature of exhaust gas going through M.C.C(Main Catalytic Converter). 2) W.C.C.(Warm-up Catalytic Converter) also decreases HC emission. To reduce HC emission, it is helpful to use W.C.C. as well as dual pipe exhaust system. 3) Using finite element method, it is shown that inner parts have much higher distribution of temperature than outer parts.