• Bulletin of the Korean Chemical Society
• /
• 제23권1호
• /
• pp.81-85
• /
• 2002

A new di-N-cyanoethylated 14-membered tetraaza macrocycle 1,8-bis(2-cyanoethyl)-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane $(L^2)$ and its nickel(II) complex $[NiL^2(OAc)]^+$ have been prepared. The square-planar complex $[NiL^2](C IO_4)_2$ can be prepared by addition of $HClO_4$ to a hot aqueous solution of $[NiL^2(OAc)]^+$ The Ni-N (tertiary amino group) bond distances $(2.008{\AA})$ of $[NiL^2](C IO_4)_2$ are relatively long, and the complex exhibits a d-d transition band at unusually long wavelength (ca. 515 nm). The complex $[NiL^2](C IO_4)_2$ rapidly reacts with acetate ion or ethylenediamine (en) to produce $[NiL^2(OAc)]^+$ or [Ni(en)_3]^{2+}$, respectively, and is readily decomposed in NaOH (0.01 M) solution. The chemical properties of $[NiL^2]^{2+}$ as well as its synthetic procedure are quite different from those for other related 14-membered tetraaza macrocyclic complexes. Effects of the N-cyanoethyl and C-methyl groups on the properties of $L^2$.

• 대한수학회보
• /
• 제47권5호
• /
• pp.961-971
• /
• 2010

As an application of 'reverse engineering' technique introduced by R. Fintushel, D. Park and R. Stern [9], we present a simple way to construct an infinite family of exotic (2n+2l-1)$\mathbb{CP}^2#$(2n+4l-1)$\overline{\mathbb{CP}}^2$'s for all $n\;{\geq}\;0$, $l\;{\geq}\;1$.

• 한국환경과학회지
• /
• 제6권1호
• /
• pp.9-16
• /
• 1997

We investigated and analysed the actual conditions and characteristics of railroad noise levels for 17 sites in the vicinity of the Seoul-Pusan Line. The results i,we summarized as follows : 11 Railroad noise level ranged to 64 ~ 74 $L_{eq}$ dB(A) at day time and ranged to 60 ~ 72 $L_{eq}$ dB(A) at night time. 21 Increased night noise level depend on the increase of trains passing at night time. 31 The major factor of Increased noise level in the vicinity of stations are using loudspeakers and stream whistle on trains. 4) Decreased effect of noise according to distance is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$=$78.59^{X-0.056}$, n =25, r=-0.994, s.e. =1.007 $P_{av}$ = $105.68X^{-0.073}$, n =25, r =-0.997, s.e. = 1.007 Also increased and decreased effect of noise according to floor in apartment Is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$ = $64.238X^{0.0567}$, n = 39, r = 0.787, s.e. = 1.004 $P_{av}$ =79.963X0.0524, n =39, r =0.689, s.e. = 1.056 5) Average noise level in high floor is over 70 $L_{eq}$ dB(A) at day and night time. so more detailed soundproofing countermeasured in high floors apartment is required.

• Bulletin of the Korean Chemical Society
• /
• 제14권2호
• /
• pp.234-238
• /
• 1993

The method of study describes the determination of the nanogram amounts of mono-, di-, and tri-butyltin compounds in sea water. The procedure is based on 1) the conversion of tin compounds to non-ionic species by sodium tetraethyl borate as an alkylation reagent, 2) one-step ethylation and 3) extraction. No further purification or concentration of the extract was required before GC-FPD (Flame Photometric Detector). The detection limits for mono-, di- and tri-butyltin were 12.50, 6.02, and 4.19 ng/L. The linear range (0-120 ng/L) was solely dependent on the detector response height. Sea water samples (n=24) were obtained from Masan Bay, Busan, Ullsan, Gunsan, Sockcho, Yeasu, Donghae, Inchun, Kanghwa, and Ahsan in Korea. The samples were collected between June, 1992 to July, 1992 and the distribution of monobutyltintrichloride (MBTC), dibutyltindichloride (DBTC), and tributyltinchloride (TBTC) in sea water was recorded. The concentrations of butyltin compounds in seawater were found to be in the range of N.D. (not detected)-61.93 ng/L for MBTC, N.D.-32.16 ng/L for DBTC, and N.D.-55.76 ng/L for TBTC.

• Tuberculosis and Respiratory Diseases
• /
• 제78권3호
• /
• pp.232-238
• /
• 2015

Background: A relationship between low vitamin D levels and the development or outcomes of respiratory diseases has been identified. However, there is no data on the vitamin D status in patients with acute eosinophilic pneumonia (AEP). We evaluated the vitamin D status in patients with AEP among South Korean military personnel. Methods: We prospectively compared the serum levels of total 25-hydroxyvitamin D [25(OH)D], 25(OH)D3, and 25(OH)D2 among patients with AEP, pulmonary tuberculosis (PTB), and community-acquired pneumonia (CAP). Results: In total, 65 patients with respiratory diseases, including AEP (n=24), PTB (n=19), and CAP (n=22), were identified. Of the 24 patients with AEP, 2 (8%) had deficient total 25(OH)D levels (<10 ng/mL), 17 (71%) had insufficient total 25(OH)D levels (${\geq}10$ to <30 ng/mL), and only 5 (21%) had sufficient total 25(OH)D levels (${\geq}30$ to <100 ng/mL). The difference in the total 25(OH)D levels among patients with AEP, PTB, and CAP was not statistically significant (p=0.230). The median levels of total 25(OH)D, 25(OH)D3, and 25(OH)D2 were 22.84, 22.84, and 0.00 ng/mL, respectively, and no differences in the 25(OH)D level were present among patients with AEP, PTB, and CAP with the exception of the total 25(OH)D level between patients with AEP and PTB (p=0.042). Conclusion: We have shown that low vitamin D levels are frequently found in patients with AEP and are comparable with those in patients with PTB and CAP.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 하계종합학술대회논문집
• /
• pp.383-386
• /
• 1998

The microwave dielectric properties and sintering properties of the xCaTi $O_{3}$-yMgTi $O_{3}$-z(L $i_{1}$2/N $d_{1}$2/)Ti $O_{3}$ systems were investigated for the development of microwave dielectric materials. Dielectric constants decreased with increasing the amounts of MgTi $O_{3}$ and increased with reducing the amounts of MgTi $O_{3}$ and increased with reducing (L $i_{1}$2/N $d_{1}$2/)Ti $O_{3}$ contents. The microscopic structures were mixed phase with a little second phase. We found some compositions with .tau.$_{f}$ changed from positive to negative value with increasing MgTi $O_{3}$ or (L $i_{1}$2/N $d_{1}$2/)Ti $O_{3}$ contents. The microscopic strucstures were mixed phase with a little second phase. We found some compositions with .tau.$_{f}$ =0ppm/.deg.C. these compmsitions exhibited the stable dielectric properties on the various sintering temperatures.res.

• Plant Biotechnology Reports
• /
• 제2권4호
• /
• pp.245-252
• /
• 2008

The genetic status of somatic embryo-derived plantlets of Cymbopogon flexuosus was examined by randomly amplified polymorphic DNA (RAPD) analysis. Auxins such as 2, 4-dichlorophenoxyacetic acid (2, 4-D) (1-4 mg/l) were used in Murashige and Skoog (MS) medium for induction of calli from rhizomatous explants of Cymbopogon flexuosus. Optimum calli were induced on MS medium supplemented with 2, 4-dichlorophenoxyacetic acid (2, 4-D) (3.5 mg/l) alone or in combination with $N^6-benzyladenine$ (2 mg/l). Somatic embryogenesis was achieved from long term calli when cultured on MS medium containing 2, 4-dichlorophenoxyacetic acid (2, 4-D) (2 mg/l) along with $N^6-benzyladenine$ (BA) (1-2 mg/l). Regeneration was achieved when freshly induced embryogenic calli were sub-cultured on MS medium supplemented with $N^6-benzyladenine$ (3 mg/l) alone. Long-term cultured embryos showed profuse minute rooting on regeneration medium supplemented with N6 -benzyladenine (3 mg/l). Microshoots were rooted in the presence of indole-butyric acid (IBA) (2 mg/l). DNA samples from the mother plant and 18 randomly selected regenerated plants from a single callus were subjected to RAPD analysis with 6 arbitrary decamer primers for the selection of putative somaclones. A total of 64 band positions were scored, out of which 19 RAPD bands were polymorphic. From genetic similarity coefficient based on RAPD band data sharing, it was found that the majority of the clones were almost identical or more than 92% similar to the mother plant, except CL2 and CL9 (66%) which showed highest degree of genetic change with CL2 and CL9 showing presence of two non-parental bands each.

• 한국식품위생안전성학회지
• /
• 제28권4호
• /
• pp.349-353
• /
• 2013

본 연구는 20% ortho-phenylphenol을 함유한 훈증소독제, Fumagari OPP$^{(R)}$의 Staphylococcus aureus (S. aureus)에 대한 살균효과를 평가하기 위해, French standard NF T 72-281에 따라 수행하였다. 배양 현탁액 중 S. aureus의 균수 (N 값), 훈증소독제에 노출된 각 담체의 균수 (n1, n2, n3), 평판배지법에 의한 시험균주 현탁액 중 균수 (N1), 여과법에 의한 시험균주 현탁액 중 균수 (N2), 그리고 대조담체의 회복 균수의 평균값 (T 값)을 예비실험을 통해 구하였다. 또한, 훈증소독제에 노출된 S. aureus의 감소 균수 (d 값)는, T 값, 회복액 중 균수의 평균값 (n'1) 그리고 배지의 담체에서 증식한 균수의 평균값 (n'2) 등을 이용하여 산출하였다. N 값은 $4.0{\times}10^8$ CFU/mL이었으며, n1, n2, n3은 각각 0.5N1, 0.5N2, 0.5N1 보다 높게 나타났다. 그리고 T값은 $3.4{\times}10^6$ CFU/mL이었다. 훈증소독제의 살균효과에 있어서, d 값은 6.43 logCFU/mL이었다. 훈증소독제에 대한 프랑스 기준에 따르면, 효과적인 살균력을 갖는 훈증소독제의 d 값이 5 logCFU/mL 이상이어야 하는 것으로 규정하고 있다. 본 연구의 결과로부터, Fumagari OPP$^{(R)}$는 S. aureus에 대해 높은 살균효과를 갖는 것으로 나타나, 병원성 세균으로 오염된 식품재료와 주방기기의 소독에 적용할 수 있을 것으로 사료된다.

• Membrane and Water Treatment
• /
• 제9권4호
• /
• pp.263-271
• /
• 2018

The objective of this work was to analyze organic matter removal, nitrification, biomass growth and membrane fouling in a submerged flat-sheet membrane bioreactor, fed with synthetic wastewater, of similar composition to the effluents generated in a fish meal industry. After biomass acclimatization with saline conditions of 12 gNaCl/L and COD/N ratio of 15 in the bioreactor, results showed that the organic matter removal was higher than 90%, for all organic loading rates (0.8, 1, 1.33 and $2gCOD/L{\cdot}d$) and nitrogen loading rates (0.053, 0.067, 0.089 and $0.133gN/L{\cdot}d$) tested during the study. However, nitrification was only carried out with the lowest OLR ($0.8gCOD/L{\cdot}d$) and NLR ($0.053gN/L{\cdot}d$). An excessive concentration of organic matter in the wastewater appears as a limiting factor to this process' operating conditions, where nitrification values of 65% were reached, including nitrogen assimilation to produce biomass. The analysis of membrane fouling showed that the bio-cake formation at the membrane surface is the most impacting mechanism responsible of this phenomenon and it was demonstrated that organic and nitrogen loading rates variations affected membrane fouling rate.

• 한국환경보건학회지
• /
• 제12권1호
• /
• pp.69-78
• /
• 1986

In order to determine the content levels of trace metals in cow's milk, 79 market milk samples were collected from markets in major cities of Korea from July to August, 1985 and analyzed for content levels of Cu, Fe, Zn, Mn, Pb, Cd. The Results were as follows Cu, average 43.5 $\mu$g/l range 14 ~ 172.7 $\mu$g/l Fe, average 398.4 $\mu$g/l range 35 ~ 1,873 $\mu$g/l Zn, average 2.917 mg/l range 1.233 ~ 7.46 mg/l Mn, average 26.74 $\mu$g/l range 7.6 ~ 102 $\mu$g/l Pb, average 33.9 $\mu$g/l range N.D. ~ 105 $\mu$g/l Cd, average 1.73 $\mu$g/l range N.D. ~ 5.4 $\mu$g/l