• Honam Mathematical Journal
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• v.28 no.3
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• pp.377-386
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• 2006

For a commutative ring with unity R, it is proved that R is a PF-ring if and only if the annihilator, $ann_R(a)$, for each $a{\in}R$ is a pure ideal in R. Also it is proved that the polynomial ring, R[x], is a PF-ring if and only if R is a PF-ring. Finally, we prove that M as an R-module is PF-module if and only if M[x] is a PF R[x]-module. Also M is a PP R-module if and only if M[x] is a PP R[x]-module.

• Korean Journal of Animal Reproduction
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• v.15 no.3
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• pp.221-224
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• 1991

This study was undertaken to evaluate the effect of rabbit peritioneal fluid(rPF) on in vitro maturtion of porcine follicular oocytes. From does 20h after hCG injection, rPF was aspirated aseptically at laparatomy, and then centrifuged, filtrated, and preincubated immediately for 12h. Porcine follicular oocytes isolated from ovaries of slaughtered animals were incubated in TCM-HEPES＋10% FCS, TCM-HEPES＋rPF(v/v, 50/50), or rPE only and examined the nuclear maturation after aceto-orcein or hochest staining. After identifying the optimal incubation time, this experiment was repeated for 5 times. Under the TCM-HEPES containing hormones and serum codition, the time range of porcine follicular oocyte maturation was 38 to 44 hours and the optimal time of maturation of follicular oocyte in vitro was 42 hour cultivation, respectively. The maturatin rates(89.4% and 92.7%) of porcine follicular oocytes cultured in the media with 50% rPF or only rPF were signifciantly higher thanthat (84.6%) of oocytes cultured with TCM-HEPES, respectively. These results suggest that the unknown components(s) of rPF promoted in vitro maturation of porcine follicular oocytes.

• Journal of the Korea Furniture Society
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• v.12 no.2
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• pp.29-38
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• 2001

This study was carried out to develope a new process of flattening bamboo pieces(3 months old) by two steps of utilizing microwave oven and hot press. Internode bamboo pieces were impregnated with low molecular weight phenol formaldehyde resin (PF) under vacuum of 76 cmHg, heated in a household microwave oven in 1 minute, pressed on the temperature of $145^{\circ}C$ by the hot press for 10 minute, and then cooled by the cold press in their flattened form. The physical and mechanical . Properties of compressed flattened bamboo were as follows: 1) PF1(Mw:427) and PF2(Mw:246) sol. met the success of flattening of internode bamboo pieces in both of P. bambusoides and P. nigra var. PF2 showed the more plasticity to flatten the bamboo than PFI. The PF2 sol. with low molecular weight(Mw:246) gave the more weight gain than that of PF1 in the equal concentration. PF1 of 5% (NVC) and PF2 of 10% (NVC) sol. gave the best result for physical and mechanical properties and from a economical view point. 2) The PFI of 5% (NVC) sol. with low molecular weight decreased the water absorption of 62-63% and increased the bending strength (MaR) of 80-90%, compression strength of 43-54%. 3) The PF2 of 10% (NVC) sol. with low molecular weight decreased the water absorption of 56-57% and increased the bending strength (MaR) of 64-86%, compression strength of 39-63%.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.2
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• pp.63-70
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• 2017

Native fluorescent pseudomonas bacteria were isolated from rhizosphere soil of mulberry and were evaluated against powdery mildew. In vitro conidial germination study showed significant (P<0.05) variation in conidial germination by bacterial strains Pf1 and Pf3. Mildew incidence was significantly varied due to treatment with various pseudomonas strains in vivo. Significantly (P<0.05) less mildew incidence was in plants treated with the bacterial strain Pf1 (9.11%) followed by Pf3 (13.48%) controlling 69.40% and 54.75% respectively compared with untreated control. Similarly, mildew severity was least (8.51%) in plants treated with strain Pf1 followed by Pf5 (9.23%) and Pf3 (9.72%) controlling the severity by 84.51%, 77.01% and 71.96% respectively compared with control. The bacterial strains significantly influenced biochemical constituents such as chlorophyll, protein and soluble sugar content of the mulberry leaf. Similarly, bacterial strains significantly increased the activity of the peroxidase (PO) and Polyphenol oxydase (PPO) activity from $7^{th}$ day up to the $28^{th}$ day after treatment. The strain Pf1, Pf3 and Pf5 exhibited a marked enhancement in the peroxidase at different periods of infection. Significant (P<0.01) negative correlation was found between powdery mildew severity with phenol content ($R^2=0.67$) as well as peroxidase ($R^2=0.92$) and polyphenol oxidase ($R^2=0.72$) activity thus confirms induction of systemic resistance in mulberry by pseudomonas bacteria. The study shows scope for exploration of rhizosphere fluorescent pseudomonas bacteria for induction of systemic resistance in mulberry to contain powdery mildew disease effectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.57-63
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• 2020

To develop simple acrosome staining of horse spermatozoa, this study tested the binding properties of Coomassie brilliant blue G or R on the sperm smears after 3.7% paraformaldehyde (PF) or 35% methanol (MT) fixation. After being fixed with PF and stained with 0.05, 0.1, or 0.2 % of CBB G or R for 2 min, horse spermatozoa were examined for their intact acrosome status. The intact acrosome of fresh horse spermatozoa were 62.6% and 61.5% with 0.05% of the G and R CBB solution, but 80.2 and 79.7% with G type and 78.1 and 76.0% with R type. On the other hand, when MT was used for fixation, the acrosome reacting sperm ratio was 3.5%, but was 9.0% in the case of PF. These results show that the intact acrosome of horse sperm could be judged using a 0.1~0.2% CBB G or R staining technique. PF would be an essential fixative for examining acrosome reacting horse spermatozoa. This method could be used to identify sperm with a damaged acrosome during low-temperature storage or cryopreservation for artificial insemination of horses.

• Kyungpook Mathematical Journal
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• v.47 no.1
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• pp.127-132
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• 2007

In this paper, we show that if R is a commutative ring with identity and (S, ${\leq}$) is a strictly totally ordered monoid, then the ring [[$R^{S,{\leq}}$]] of generalized power series is a PF-ring if and only if for any two S-indexed subsets A and B of R such that $B{\subseteq}ann_R(|A)$, there exists $c{\in}ann_R(A)$ such that $bc=b$ for all $b{\in}B$, and that for a Noetherian ring R, $[[R^{S,{\leq}}$]] is a PP ring if and only if R is a PP ring.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.435-437
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• 2006

KSTAR (Korea Superconducting Tokamak Advanced Research) 장치는 Tokamak 개념의 핵융합 연구 장치로서 플라즈마를 가두기 위한 자장을 발생하는 토로이달 자장(Toroidal Field, TF) 코일과 플라즈마 발생 및 형상 조정을 위한 폴로이달 자장 (Poloidal Filed, PF) 코일로 구성되며, 초전도 코일을 이용한다. TF코일의 전원장치로는 40 kA급의 안정된 직류 전원장치가 필요하며, PF 코일의 전원장치로는 빠른 전류상승 및 피드백 기능을 갖춘 정밀 대전류 전원을 필요로 한다. 또한 초전도 코일의 ??????치현상 발생 시 코일과 전원장치 보호를 위한 대전류 직류 차단시스템을 필요로 한다. KSTAR 장치의 설계에 의하면 상하 7쌍의 초전도 PF 코일에 약 1MA/sec급의 고속 전류구동을 운전 시나리오에 따라 인가하여 핵융합 연구를 위한 플라즈마를 생성한다. 본 논문은 TF 및 PF 코일에 대전류를 인가하기 위해서 개발된 전원장치 (Power Supply, PS)에 관한 연구이다.

• 한국전기화학회:학술대회논문집
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• 2004.04a
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• pp.54-54
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• 2004

• The Korea Journal of Herbology
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• v.26 no.3
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• pp.37-45
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• 2011

Objectives : This study focused on Schisandrae Fructus (SF) and Perilae Folium (PF), traditional medicine herbs and health functional food in Korea, Japan and China. We investigated various pharmacological activities that include a potential source of free radical scavenging, anti-viral, anti-microbial, anti-allergy and anti-inflammatory activities. Methods : We conducted an investigation of total contents of phenolic and flavonoid compounds in these single herbal extraction with/without combined to mixture. We also measured antioxidant activities such as DPPH free radical scavenging, SOD-like scavenging, nitrite scavenging and hydroxyl radical scavenging activities, xanthine oxidase inhibition, linoleic acid peroxidation inhibition, and reducing power. Results : As the results, contents of total phenoilc compounds and flavonoids were higher in those of PF than those of SF. Those of SF+PF mixture showed the synergy effects compared with those of SF and PF single extractions. Activities of DPPH free radical and SOD-like scavenging in 1 mg/mL concentration increased in dose dependent manners. That of SF increased compared with that of PF. That of SF and PF mixture also increased compared with that of BHA as a positive control. The other antioxident activities also showed similar to patten of activity of DPPH free radical scavenging. When combined to SF and PF extractions, there was showed synergic effect compared with those of BHA, excepted activities of xanthine oxidase inhibition and reducing power. Taken together, SF and PF have high phenolic and flavonoid compounds content furthermore, antioxidant activities in SF and PF mixture showed more synergy effect compared with those of BHA. Conclusions : Therefore, these findings suggest that SF and PF mixture may offer functional materials potential for development of functional beverage. But further studies are needed for the identification of the active compounds.

• YAKHAK HOEJI
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• v.46 no.5
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• pp.337-342
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• 2002

Propofol(2,6-diisopropyl phenol) is a phenol derivative that is chemically distinct from other intravenous sedative hypnotics. It has been extensively used as a short term anesthetic agent, because of the rapid onset and short duration of action. Propofol microemulsion system was prepared with different concentrations of ethyl oleate, $Solutol^{(R)}$ HS 15 and $Kollidon^{(R)}$ 17 PF. Propofol microemulsions were studied by transmittance, viscosity, particle size, in vitro release and pharmacokinetics. The range of transmittance of A group with 4% ethyl oleate and that of B group with 5% ethyl oleate were 92.6~95.1 and 91.3~94.2%, respectively. Transmittance 1~2% decreased as concentration of $Kollidon^{(R)}$ 17 PF was increased and increased 0.8~3.3% when 10 times diluted with normal saline. The viscosity of A and B group were in the range of 3.9~4.1 mPaㆍsec and 4.4~5.3 mPaㆍsec, respectively. The particle sizes of A and B group increased as amount of $Kollidon^{(R)}$ 17 PF. Also, release of propofol was slowly increased as the amount of $Kollidon^{(R)}$ 17 PF was increased. Propofol plasma concentration by i.v injection showed 2-compartment model. Pharmacokinetics of A-5 was similar to that of commercial emuision(POFOL).