• Journal of Plant Biotechnology
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• 제34권3호
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• pp.263-269
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• 2007

식물 세포나 조직의 배양에서 배지의 salt strength, sucrose 농도, 질소 함량과 질소원의 종류 및 그 비율 등이 세포 또는 조직의 생장에 영향을 미친다. 본 연구에서는 Agar를 함유한 MS 기본배지와 BA 1 mg/L를 첨가한 MS 기본 액체배지에서 계대배양을 통하여 생산한 다신초를 액아와 본엽이 $2{\sim}3$매 되도록 분할한 신초를 이용하여 MS 액체배지의 salt strength와 sucrose 농도 및 $NH_4/NO_3$ 비율이 고추냉이 신초의 생육에 미치는 영향을 조사하여 고추냉이 유묘의 생산에 필요한 최적 배지조건을 구명하였다. 고추냉이 신초의 증식에는 MS 액체배지의 salt strength는 기본조성이 가장 적합한 것으로 나타났으며, $1/4{\sim}1/2x$ 또는 2x MS 배지에서는 고추냉이 유묘의 생장이 크게 억제 되었다. 기본조성의 MS 액체배지에 sucrose 3%를 첨가하였을 때 고추냉이 신초의 생장이 가장 우수한 것으로 나타났으나 sucrose 농도 $1{\sim}6%$ 범위에서 신초의 수와 길이는 유의성 있는 차이를 보이지 않았다. 기본조성의 MS 액체배지에서 질소원으로 ${NH_4}^+$과 ${NO_3}^-$의 비율을 10:50으로 조절하였을 때 고추냉이 신초의 생장이 가장 우수한 것으로 나타났으며, ${NH_4}^+$의 비율이 증가할수록 생장은 억제되었다.

• Bulletin of the Korean Chemical Society
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• 제11권4호
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• pp.328-331
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• 1990

Three crystal structures of dehydrated Cd(II) and Rb(I) exchanged zeolite A, $Cd_{4.0}Rb_{4.0}-A (a = 12.204(3) {\AA}), Cd_{5.0}Rb_{2.0}-A (a = 12.202(1) {\AA}),$ and $Cd_{5.95}Rb_{0.1}-A (a = 12.250(2) {\AA}),$ have been determined by single-crystal X-ray diffraction techniques. Their structures were solved and refined in the cubic space group Pm3m at $21(1)^{\circ}C.$ All crystals were ion exchanged in flowing streams of mixed $Cd(NO_3)_2·4H_2O$ and $RbNO_3$ aqueous solution with total concentration of 0.05 M. All crystals were dehydrated at ca. $450^{\circ}C$ and $2×10^{-6}$ Torr for 2 days. In all of these structures, $Cd^{2+}$ ions are found on threefold axes, each nearly at the center of a 6-oxygen ring. The first three $Rb^+$ ions per unit cell preferentially associate with 8-oxygen rings, and additional $Rb^+$ ions, if present, are found on threefold axes in the large cavity. The final $R_1$ and $R_2$ values for the three structures are 0.087 and 0.079, 0.059 and 0.067, and 0.079 and 0.095, respectively.

• Bulletin of the Korean Chemical Society
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• 제16권11호
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• pp.1084-1088
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• 1995

A complete solid solution (SrLaAl1-xNixO4) between insulating SrLaAlO4 and metallic SrLaNi(Ⅲ)O4 oxides were prepared under high oxygen pressure (1.5 kbar, 800 ℃). They have tetragonal K2NiF4-type structure in all the solid solution range. Compared with lattice parameters of the same solid solution prepared under normal condition (1 bar, 1200 ℃), large decrease in the c-parameter was induced by high pressure treatment while no noticeable variation of the a-parameter was observed. Although marked changes of structural parameters, magnetic susceptibilities, and electron paramagnetic resonance spectra were consistently occurred before and after x=0.5, overall behaviors were essentially the same with those of solid solution prepared under normal condition. Such a phenomenon is explained by assuming the formation of partially filled narrow σ*x2-y2 band for x>0.5. Lattice contraction along the c-axis by high pressure treatment seems not to broaden this band. Particularly, the continuous absorption characteristic of a high free carrier concentration for x>0.5 and the absence of Ni-O in-plane stretching mode in the infrared absorption spectra supports this picture. However, the conductivities increasing with temperature for all solid solution suggest that some localization character, of probably Anderson type, remains for x>0.5.

• Asian-Australasian Journal of Animal Sciences
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• 제24권10호
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• pp.1393-1398
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• 2011

Four 4-month old Charolais${\times}$Dorset male sheep (initial liveweight $25.0{\pm}1.1\;kg$), fitted with rumen and abomasal fistulas and nourished by total intragastric infusions, were used to study the relationships between methionine (Met) supply, nitrogen (N) retention and plasma insulin-like growth factor-I (IGF-I). Four graded levels of Met, i.e. 0 g/16 g N, 1.76 g/16 g N, 3.52 g/16 g N and 7.04 g/16 g N, were infused into abomasums as experimental treatments. The sheep and treatments were allocated in a $4{\times}3$ incomplete Latin square design (Yudon square design). The experiment lasted 3 periods and each period was 10 days. Quadratic correlations were found between Met level (x, g/16 g N) and N retention (y, g/d): y = $-0.03x^2$+0.41x+2.62, $r^2$ = 0.66, n = 12, p = 0.008, and between methionine level (x, g/16 g N) and plasma IGF-I concentration (y, ng/ml): y = $0.80x^2$-4.53x+190.24, $r^2$ = 0.51, n = 12, p = 0.009. No significant correlation was found between plasma IGF-I (x, ng/ml) and N retention (y, g/d) (p>0.05). It was concluded that Met level had a significant influence on N retention and plasma IGF-I concentration whereas IGF-I might not be an important mediator in the regulation of N metabolism by Met in growing sheep nourished by total intragastric infusions.

• 한국대기환경학회지
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• 제9권2호
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• pp.147-153
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• 1993

From March 1990 to August 1991, every each 5mm bulk precipitation samples were collected at one residental area in Taejon City to investigate chemical characteristics of acid rain. Major ion concentrations of rain samples $(pH, SO_4^{2-}, NO_3^-, CL^-, NH_4^+, Na^+, K^+, Ca^{2+}, Mg^{2+})$ were analysed and compared with the concentration of air pollutants (T. S. P, $SO_2, NO_x$) that were measured by Ministry of Environment. The results of statistical analysis are as followings. Rain pH was relatively high on October and January and relatively low on August, November and February. Major anion is sulfate, and it's concentration is 2.36 times higher than nitrate's, and major cations are ammonium, sodium and calcium ion. Monthly variation of sulfate and calcium concentrations are higher than the others. Ion concentration and rain pH were correlated negatively with rainfall amount. Major ions in rain samples were $SO_4^{2-}, NO_3^-, NH_4^+, Ca^{2+}$ and regression equations are proposed by multiple regression of measured data. Also, regression equation between air pollutants(T. S. P, $SO_2$) and $SO_4^{2-}, Na^+, K^+, Ca^{2+}, Mg^{2+} ions in rain samples were made. From this wer can predict rain pH.

• 대한환경공학회지
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• 제31권10호
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• pp.901-908
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• 2009

음식물류 폐수를 생활 폐기물 소각로에 직접 분사하여 소각처리 하는 방안에 대하여 검토하였다. 소각설비는 연속 스토카식 실증플랜트를 이용하였다. 그 결과 암모니아성 질소($NH_3$-N)가 다량 함유된 음식물류 폐수를 분사 소각함으로써 질소산화물($NO_x$) 농도저감과 동시에 질소산화물($NO_x$) 저감을 위해 선택적 비촉매 환원장치(selective non-catalytic reduction ; SNCR)에서 사용되는 암모니아($NH_3$)의 사용량을 절감하는 효과를 가져왔다. 또한, 음식물류 폐수를 분사하여 2차 연소실 출구온도를 적정온도인 870~$950^{\circ}C$로 유지하여 소각량을 최대화하는 한편 폐열회수 보일러의 수관외벽 막힘현상 개선을 통한 로의 안정성 확보 및 연속운영기간의 연장을 실현하였다. 질소산화물($NO_x$), 황산화물($SO_x$) 및 다이옥신 등 대기오염물질 26개 항목에 대하여 측정을 실시한 결과 모두 배출허용 기준치 이하의 값을 나타내었다.

• Ocean and Polar Research
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• 제44권4호
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• pp.297-310
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• 2022

To understand the chemical composition of aerosols in the Cheju-Korea Straits and their contribution to the ocean by deposition, aerosol samples were collected on board R/V Eardo from November 1997 to May 1999. The average concentrations of Al, NO₃^-, non-sea-salt (nss)-SO₄^2-, and NH₄⁺ in aerosols were 2.19, 5.59, 6.16 and 2.08 ㎍ m^-3, respectively. The Al concentration in the high yellow dust period was about 100 times higher than that in the non-yellow dust period. The concentration ratio of NO₃^-/nss-SO₄^2- ranged between 0.47 and 1.5, indicating that the aerosols in the Cheju-Korea Straits are under the effects of NO_x and SO_x emitted from China, Korea and Japan. The equivalent concentration ratio of [NH₄⁺]/[nss-SO₄^2-+ NO₃^-] with the average of 0.58±0.29 indicates that nss-SO₄^2- and NO₃^- are not neutralized by NH₄⁺. A high activity concentration of ²¹⁰Pb with 1.13-1.23 mBq m^-3 was observed during the high yellow dust period, indicating that ²¹⁰Pb is easily adsorbed in the yellow dust originating from the continent of Asia. The distribution of ⁷Be and NH₄⁺ concentrations showed a strong negative linear correlation during the low yellow dust period, April 1998. The total mineral dust flux in the Cheju-Korea Straits was estimated to be 1.21×10⁶ tons yr^-1, accounting for about 12% of the annual sediment discharge via the Nakdong River. The combined annual deposition of NH₄⁺ and NO₃^- was 0.103 mole N m^-2 yr^-1 was estimated to support 4% of the annual primary productivity in the East China Sea.

• Journal of the Korean Wood Science and Technology
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• 제48권6호
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• pp.847-860
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• 2020

본 연구는 국내 숯불구이 음식점의 화구당 평균 공간을 바탕으로 제작된 모형 연소방을 이용하여 국내에서 유통되고 있는 숯과 성형숯의 연소 조건에 따라 발생하는 연소 가스와 연소 특성에 관한 연구를 수행하였다. 각각 3종의 숯과 성형숯의 연료 특성과 연소 특성을 분석하였다. 또한, 밀폐 조건과 환기 조건으로 구분하고 총 20분의 연소과정 동안 발생하는 CO, CO₂, NO_x의 농도와 O₂ 농도의 변화량을 분석하였다. 분석 결과, CO의 발생량은 밀폐 조건에서 1390~4703 ppm의 범위로 측정되었으며, 환기 시 약 29.8%~57.4%의 환기율을 보였다. CO₂는 밀폐 조건에서 1.34%~2.42%의 범위로 나타났으며, 환기시 특정 시점(10분)에 1.5% 이상 발생한 시료에서 44.1%~53.6%의 환기율을 보였다. NO_x의 발생량은 밀폐 조건의 경우 불완전 연소로 인해 지속적으로 발생량이 증가하여 29 ppm~47 ppm의 범위로 발생하는 경우와 특정 시점(1분) 이후 9 ppm~18 ppm의 범위로 비교적 일정한 발생량을 보이는 경우로 나뉘었다. 환기 조건의 NO_x 배출량은 밀폐 조건과 유사한 경향을 보였으며, 최대 62.5%의 환기율을 보였다. 따라서, 본 연구 결과를 바탕으로 숯과 성형숯의 사용환경을 모사하여 인체 유해성 평가에 활용 가능할 것으로 판단된다.

• 한국환경보건학회지
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• 제17권1호
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• pp.95-103
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• 1991

For the purpose of estimating the working environment and the relationship between the airborne lead concentration and the ZPP level in the whole blood of the workers, the airborne lead concentrations and the ZPP level were measured at the 26 plants which deal with lead, from October 5 to November 5 in 1988. Analysis of the airborne lead concentration was performed by NIOSH Method 7082, and the ZPP level was measured by a hematofluorometer. The following results are concluded. 1. The average airborne lead concentration of the lead battery manufactures is 0.025mg/m$^{3}$ and that of the secondary lead smelters is 0.023mg/m$^{3}$. There were no significant differences between industry (p>0.1) 2. At the lead battery manufacture, the process of lead powder production showed the highest concentration of 0.034mg/m$^{3}$ but there were no significant differences among the processes (p>0.1). At the secondary lead smelter, the process of dismantling waste batteries showed the highest concentration 0.141mg/m$^{3}$, and there were very significant differences among the processes (p<0.005). 3. The ZPP level in the whole blood showed significant differences between industry (p<0.10). The average ZPP level of the lead battery manufactures is 133.0 + 106.3 $\mu$g/100ml and that of the secondary lead smelters is 149.6 + 110.9 $\mu$g/100ml. 4. The correlation coefficients between the airborne lead concantration and ZPP level were 0. 426 (p<0.001) for the lead battery manufactures and 0.484 (p<0.001) for the secondary lead smelters. The correlation coefficients between the work duration (in months) and the ZPP level were 0.238 (p<0.001) for the lead battery mannfactures and 0.075 (p>0.10) for the secondary lead smelters. 5. The linear regression equation, with the airborne lead concentration as an independent variable and the ZPP level as a dependent variable, is Y=96.84+1300.34X (r=0.448, p<0.001) for the 26 plants which deal with lead. The linear regression equation, with the work duration(in months) as an independent variable and the ZPP level as a dependent variable, is Y=127.28 +0.49X (r=0.162, p<0.05). 6. The correlation coefficients between the amount of inhaled lead and ZPP level were 0.349 (p < 0.001) for the lead battery manufactures and 0.318(p<0.001) for the secondary lead smeltes. The linear regression equation for the 26 plants surveyed, with the amount of inhaled lead as an independent variable and ZPP level as a dependent variable, is Y=123.63+18.82X (r=0. 335, p<0.001).

• 대한임베디드공학회논문지
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• 제2권2호
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• pp.76-81
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• 2007

A novel multi-layer type micro gas sensor for $NO_X$ detection was designed and fabricated. Micro platform defined as type II-1 in this article for micro gas sensor was fabricated using the MEMS technology to meet the demanding needs of lower power consumption. Nano composite materials were fabricated with nanosized tin oxide powder and $\underline{m}$ulti-$\underline{w}$all $\underline{c}$arbon $\underline{n}$ano $\underline{t}$ube (MWCNT) to improve sensitivity. We investigated characteristics of fabricated multi-layer type micro gas sensor with $NO_2$ concentration variations at constant 2.2 V. Sensitivity (S) of micro gas sensor were observed to increase from 2.9, to 7.4 and 11.2 as concentrations of $NO_2$ gases increased from 2.4 ppm, to 3.6 ppm and 4.9 ppm. When 2.4 ppm of $NO_2$ gas was applied, response time and recovery time of micro gas sensor were recorded as 101 seconds and 142 seconds, respectively.