• Proceedings of the KIEE Conference
• /
• 1985.07a
• /
• pp.215-218
• /
• 1985

In this paper, The electron drift velocity was measured from an experimental study of the open end heat pipe system by induced current method as alkali metal vapour was generated in ordinary region of a drift tube. The test condition was alkali metal vapour range from 3.6 to 20.1(Torr), temperature of 667 to 755(K), and E/N of $1{\times}10^{-16}$ to $1{\times}10^{-15}(v.cm^2)$. The results of this study were obtained essentially the same as the extrapolated prediction curve for electron drift velocity in the alkali metal Vapour of J. Lucas et 31 with range of E/N: $1{\times}10^{-17}$ to $1{\times}10^{-16}(v.cm^2)$, and the electron drift velocity was obtained the result an increase in alkali to E/N range from E/N $2.8{\times}10^{-17}$ to $5.6{\times}10^{-16}(v.cm^2)$ (E/N From 2.8 to 50 Td).

• The Korean Journal of Physiology and Pharmacology
• /
• v.4 no.1
• /
• pp.73-79
• /
• 2000

This study investigated whether propofol, an intravenous, non-barbiturate anesthetic, could reduce brain damage following global forebrain ischemia. Transient global ischemia was induced in gerbils by occlusion of bilateral carotid arteries for 3 min. Propofol (50 mg/kg) was administered intraperitoneally 30 min before, immediately after, and at 1 h, 2 h, 6 h after occlusion. Thereafter, propofol was administered twice daily for three days. Treated animals were processed in parallel with ischemic animals receiving 10% intralipid as a vehicle or with sham-operated controls. In histologic findings, counts of viable neurons were made in the pyramidal cell layer of the hippocampal CA1 area 4 days after ischemia. The number of viable neurons in the pyramidal cell layer of CA1 area was similar in animals treated with a vehicle or a subanesthetic dose of propofol. In terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) assay, semiquantitative analysis of dark-brown neuronal cells was made in the hippocampal CA1 area. There was no significant difference in the degree of TUNEL staining in the hippocampal CA1 area between vehicle-treated and propofol-treated animals. These results show that subanesthetic dose of propofol does not reduce delayed neuronal cell death following transient global ischemia in Mongolian gerbils.

• Nuclear Engineering and Technology
• /
• v.52 no.1
• /
• pp.115-122
• /
• 2020

A promising method for removal of Cs ions from water and their incorporation into stable crystal structure ready for safe and permanent disposal was described. Cs-exchanged X zeolite was hot-pressed at temperature ranging from 800 to 950 ℃ to fabricate dense pollucite ceramics. It was found that the application of external pressure reduced the pollucite formation temperature. The effect of sintering temperature on density, phase composition and mechanical properties was investigated. The highest density of 92.5 %TD and the highest compressive strength of 79 MPa were measured in pollucite hot-pressed at 950 ℃ for 3 h. Heterogeneity of samples obtained at 950 ℃ was determined using scanning electron microscopy. The pollucite hot-pressed at 950 ℃ had low linear thermal expansion coefficient of ~4.67 × 10^-6 K^-1 in the temperature range from 100 to 1000 ℃.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.295-295
• /
• 2015

강우의 시 공간적 불균형이 심한 우리나라는 수자원 확보 및 관리가 어려움에 따라 신규 수자원 확보와 기존 수자원 관리의 중요성에 대한 인식이 높아지고 있다. 최근 대체수자원으로서 대두되고 있는 지하수는 지표수에 비해 이용지점에서 바로 취수하여 사용이 가능하다는 장점이 있으나, 오염이 진행되면 복구에 상당한 기간과 비용이 소요됨에 따라 철저한 관리가 필요하다. 특히 해안지역 수자원의 경우, 내륙지역에 비해 하천이 발달해 있지 않아 지하수에 대한 높은 의존도에 따른 수량적 문제와 해수와 접해있는 면적이 많음에 따라 지하수와 해수간의 유동으로 인한 수질적 문제로 지하수 관리가 더욱 어렵다. 이에 본 연구는 지하수유동해석프로그램인 Visual MODFLOW의 SEAWAT model을 이용하여 지하수위 변화에 따른 해수침투의 영향을 판단하고자 하였다. 연구지역은 태안지역의 근흥1, 근흥2 관측소의 지하수위 데이터를 사용하였으며, 2008 ~ 2014년 까지 매년 지하수위 변동에 따라 해수침투 영향을 분석하였다. 이와 함께 해수침투 영향 판단 인자인 EC, TDS는 각 관측소 데이터를 통한 환산 및 분석 진행하고, $Cl/HCO_3$ 몰비는 참고문헌을 인용하여 모델링에 의한 해수침투 영향과 관측자료 및 이온분석을 통한 영향을 비교하였다.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1998.05b
• /
• pp.216-221
• /
• 1998

A study on induction plasma deposition with ceramic materials, yttria-stabilized-zirconia ZrO$_2$-Y$_2$O$_3$ (m.p 264O $^{\circ}C$), was conducted with a view developing a new method for nuclear fuel fabrication Before making dense pellets more than 96％TD., the spraying condition was optimized through the process parameters, such as chamber pressure, plasma plate power powder spraying distance, sheath gas composition, probe position, particle size and powders different morphology. The results with a 5mm thick deposit on rectangular planar graphite substrates showed a 97.11％ theoretical density when the sheath gas flow rate was Ar/H$_2$120/20 l/min, probe position 8cm, particle size -75 ${\mu}{\textrm}{m}$ and spraying distance 22cm by AMDRY146 powder. The degree of influence of the main effects on density were powder morphology. particle size, sheath gas composition, plate power and spraying distance, in that order. Among the two parameter interactions, the sheath gas composition and chamber pressure affects density greatly. By using the multi-pellets mold wheel type, the pellet density did not exceed 94%T.D., owing to the spraying angle.

• Archives of Pharmacal Research
• /
• v.29 no.12
• /
• pp.1080-1085
• /
• 2006

A series of 8-alkoxy-4,5-dihydro-[1,2,4]triazole[4,3-a]quinoline-1-one derivatives were synthesized using 7-hydroxy-3,4-dihydro-2(1H)-quinolone as the starting material. Their anticonvulsant activities were evaluated by the maximal electroshock test (MES) and the subcutaneous pentylenetetrazole test (sc-PTZ), and their neurotoxicities were measured by the rotarod neurotoxicity test (Tox). The tests demonstrated that 8-hexyloxy-4,5-dihydro-[1.2.4]triazole[4.3-a]quinoline-1-one (4e) and 8-heptyloxy-4,5-dihydro-[1,2,4]triazole[4, 3-a]quinoline-1-one (4f) were the most potent anticonvulsants, with 4e having $ED_{50}$ values of 17.17 mg/kg and 24.55 mg/kg and protective index ($PI=TD_{50}/ED_{50}$) values of 41.9 and 29.3 in the MES and sc-PTZ tests, respectively, and 4f having $ED_{50}$ values of 19.7 mg/kg and 21.2 mg/kg and PI values of 36.5 and 33.9 in the MES and sc-PTZ tests, respectively. The PI values of 4e and 4f were many fold better than that of the marketed drugs phenytoin, carbamazepine, phenobarbital and valproate, which have PI values in the range of 1.6-8.1 in the MES test and <0.22-5.2 in the sc-PTZ test. Structure-activity relationships were also discussed.

• Journal of Animal Science and Technology
• /
• v.58 no.2
• /
• pp.5.1-5.9
• /
• 2016

Background: The milk yield can be affected by the frequency of milking per day, in dairy cows. Previous studies have shown that the milk yield is increased by 6.25 % per lactation when the milking frequency is increased from 2 to 3 times per day while the somatic cell count is decreased. To investigate the effect of milking frequency (3X vs. 4X) on milk yield and it's genetic parameters in the first and second lactations of the Iranian Holstein dairy cows, a total of 142,604 test day (TD) records of milk yield were measured on 20,762 cows. Results: Heritability estimates of milk yield were 0.25 and 0.19 for 3X milking frequency and 0.34 and 0.26 for 4X milking frequency throughout the first and second lactations, respectively. Repeatability estimates of milk yield were 0.70 and 0.71 for 3X milking frequency and 0.76 and 0.77 for 4X milking frequency, respectively. In comparison with 3X milking frequency, the milk yield of the first and second lactations was increased by 11.6 and 12.2 %, respectively when 4X was used (p < 0.01). Conclusions: Results of this research demonstrated that increasing milking frequency led to an increase in heritability and repeatability of milk yield. The current investigation provided clear evidences for the benefits of using 4X milking frequency instead of 3X in Iranian Holstein dairy cows.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.32 no.3
• /
• pp.1-12
• /
• 2019

Objectives: Amygdalin is abundant in the seeds of bitter almond and apricots of the Prunus genus and other rosaceous plants. Amygdalin is known to have antitussive and anticancer activities. Apoptosis, also known as programmed cell death, is an important mechanism in cancer treatment. Methods: In the present study, we investigated whether the aqueous extract of Amygdalin induces apoptotic cell death in ME-180 cervical cancer cells. For this study, 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, terminal deoxynuclotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, flow cytometric analysis, DNA fragmentation assay, Western blot, and caspase-3 enzyme assay were performed on ME-180 cervical cancer cells. Results: Through morphological and biochemical analyses, it was demonstrated that ME-180 cells treated with Amygdalin exhibit several apoptotic features. The treatment of Amygdalin increased the Bax expression and caspase-3 enzyme activity and decreased Bcl-2 expression. Here, we have shown that Amygdalin induces apoptotic cell death in ME-180 cervical cancer cells through Bax-dependent caspase-3 activation. These results suggest the possibility that Amygdalin exerts anti-tumor effect on human cervical cancer.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.11
• /
• pp.1757-1760
• /
• 2005

A series of 6-alkyloxyl-3,4-dihydro-2(1H)-quinoliones (5a-5n) were synthesized through nitration, reduction, diazotization, hydrolysis and alkylation from 3,4-dihydro-2(1H)-quinolione. Their structures were characterized by IR, $^1H$-NMR and MS. The anticonvulsant activity was evaluated by the Maximal electroshock test (MES) and the subcutaneous pentylenetetrazole (Metrazole) test (sc-Met). The neurotoxicity was measured by the Rotarod test (Tox). The result showed that 6-hexyloxy-3,4-dihydro-2 (1H)-quinolinone (5c) was potent in anti-MES and anti-scMet test with $ED_{50}$ of 24.0 mg/kg and 21.2 mg/kg, respectively, albeit its $TD_{50}$ (67.6 mg/kg) revealed the high neurotoxicity. 6-Benzyloxy-3,4-dihydro-2(1H)-quinolinone (5f) was less effective against MES induced seizure with $ED_{50}$ of 29.6 mg/kg, but no neurotoxicity was observed even under 300 mg/kg. Its Protective index (PI) was greater than 10 preferable to Phenytoin, Carbamazepin, Phenobarbital and Valproate.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.17 no.2
• /
• pp.75-81
• /
• 2007

Densification and grain growth have been investigated in 5 wt% $U_3O_8$ seeded $UO_2$ and compared with those of the common $UO_2$ pellet. $UO_2$ compacts and $U_3O_8$ seeded $UO_2$ compacts were sintered at $1300{\sim}1700^{\circ}C$ for 0 h to 4 h. Density and grain size of the sintered pellets were measured by the water immersion method and the image analyzer, respectively. The seeded pellet has a slightly lower density during the intermediate sintering stage. However, the difference of density between two pellets decreases to about 0.5%TD with increasing the sintering temperature. The grain size of the two pellets is similar until $1600^{\circ}C$ but that of the seeded pellet rapidly increases with increasing the sintering temperature.