• 한국산림과학회지
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• 제90권4호
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• pp.476-487
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• 2001

본 연구는 내음수(耐陰樹)가 임상(林床)의 낮은 광도조건에 적응하는 기작을 구명하기 위해서, 양수(陽樹)와 내음수(耐陰樹)의 생육 광도 저하에 대한 광합성계(光合成系)의 적응반응을 서로 비교하였다. 이태리포플러, 음나무, 졸참나무 1년생 묘목을 대상으로 PPFD $920{\mu}mol\;m^{-2}s^{-1}$과 PPFD $80{\mu}mol\;m^{-2}s^{-1}$의 광도조건에서 5개월간 생장한 개체의 엽록소함량, 잎의 분광특성, 광합성특성 등을 조사하였다. 그 결과 양수인 이태리포플러는 생육 광도의 저하로 엽면적, 단위 엽면적 당의 엽록소함량, 빛의 흡수율 및 광합성에 대한 이용효율 등이 감소하고, 광합성의 광화학계 및 탄소고정계의 활성 저하로 낮은 광합성능력을 나타냈다. 그러나 내음성이 이태리포플러보다 강한 음나무와 졸참나무는 엽면적, 엽록소함량, 순양자수율을 증가시켜 빛의 흡수량과 광합성에 대한 이용효율을 높이는 적응반응을 나타냈다. 그리고 이들 수종은 낮은 광도에서도 광합성의 광화학계 및 탄소고정계의 활성이 정상적으로 유지되고 있음을 알 수 있었다.

• Journal of Ecology and Environment
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• 제34권4호
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• pp.401-410
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• 2011

We assayed the effects of simulated acid rain on the mass loss, $CO_2$ evolution, dehydrogenase activity, and microbial biomass-C of decomposing Sorbus alnifolia leaf litter at the microcosm. The dilute sulfuric acid solution composed the simulated acid rain, and the microcosm decomposition experiment was performed at 23$^{\circ}C$ and 40% humidity. During the early decomposition stage, decomposition rate of S. alnifolia leaf litter, and microbial biomass, $CO_2$ evolution and dehydrogenase activity were inhibited at a lower pH; however, during the late decomposition stage, these characteristics were not affected by pH level. The fungal component of the microbial community was conspicuous at lower pH levels and at the late decomposition stage. Conversely, the bacterial community was most evident during the initial decomposition phase and was especially dominant at higher pH levels. These changes in microbial community structure resulting from changes in microcosm acidity suggest that pH is an important aspect in the maintenance of the decomposition process. Litter decomposition exhibited a positive, linear relationship with both microbial respiration and microbial biomass. Fungal biomass exhibited a significant, positive relationship with $CO_2$ evolution from the decaying litter. Acid rain had a significant effect on microbial biomass and microbial community structure according to acid tolerance of each microbial species. Fungal biomass and decomposition activities were not only more important at a low pH than at a high pH but also fungal activity, such as $CO_2$ evolution, was closely related with litter decomposition rate.

• 한국광학회:학술대회논문집
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• 한국광학회 2000년도 하계학술발표회
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• pp.28-29
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• 2000

Optical power splitters and/or couplers are important components for optical signal distribution between channels both in wavelength division multiplexing(WDM) systems and photonic integrated circuits(PICs). Since polarization is usually not known after propagation in an optical fiber, passive WDM components have to be polarization insensitivity, Compared to alternatives such as directional couplers or Y-junction splitters, splitters based on multimode interference(MMI) have found a growing interest in recent yens because of their desirable characteristics, such as compact size, low excess loss, wide bandwidth, polarization independence, and relaxed fabrication tolerances$^{(1)}$ . These devices have been fabricated in polymers, silica, or III-V semiconductor materials. A1 $\times$ 4 MMI power splitter on InP materials that were suitable for application in the 1.55-${\mu}{\textrm}{m}$ region$^{(2)}$ . However, the fabrication process of the structure is too complicated and the photolithography tolerance is very tight. Also, a 1 $\times$ 16 InGaAsP/InP MMI power splitter with an excess loss of 2.2dB and a splitting ratio of 1.5dB was demonstrated by using deep etching$^{(3)}$ . The deep etching of the sidewalls through the entire guide layer of the slab waveguide resulted in a number of drawbacks$^{(4)}$ . (omitted)

• Journal of Plant Biology
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• 제17권4호
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• pp.31-37
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• 1974

Seedlings of Nongbaek representing strong cold tolerant variety of rice plant, Jinheung of medium variety and Tongil of weak variety were used respectively for the present study. These seedlings were water cultured in phytotron which maintained at the daytime and night temperature of 30-$25^{\circ}C$, 20-2$0^{\circ}C$, 20-15$^{\circ}C$ and 15-1$0^{\circ}C$. The growth rate of plant height, tillering rate, increase in dry weight and absorption pattern of important mineral nutrients at their early growth stage under each temperature conditions were observed. Generally, it appeared that Nongbaek was more active in the growth of plant height than Jinheung, and Jinheung was more active than Tongil under low temperature condition. The tillering rate of these three varieties was equally rapid while it was decreased in the order of weak cold tolerant variety, such as Tongil, Jinheung and Nongbaek as the temperature declined gradually. The dry weigh tincreasing curve showed almost the same pattern in the varieties at the treatment of each temperature. Under low temperature conditions, Nongbaek showed higher absorption rate of N per dry weight and higher absorption amount of per plant body, Jinheung followed and Tongil was the lowest. The absorption amount of P2O5 increased in the top part compared with the roots as temperature rose and decreased as temperature declined. There seemed to be no difference of absorption among the varieties which have different cold tolerance each other. Under low temperature the absorption rate of K per dry weight was high, as a whole, especially Nongbaek was markedly higher than the other two. The absorption rate of Ca, Mg and Fe was also equally high in all varieties under low temperature and Nongbaek showed a more absorptive tendency in the absorption amount under low temperature.

• 여성건강간호학회지
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• 제6권3호
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• pp.413-426
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• 2000

The purposes of this study is to examine the degree of dysmenorrhea and self-management of dysmenorrhea in high school girls and to provide basic information for health education. This research is the contents of the characteristics and self-management of dysmenorrhea and thereby serve to provide some theoretical grounds for the health education of high school-girl students. The subjects of this study are the 376 girl students of a high school in Taegu. This study was conducted by collecting data from April 3rd to 7th, 2000. The instruments used for this study by the researcher of this study based on Choi, Myung-Ok's (1992) menstrurational symtom scale (8 items) and factors used to dysmenorrhea scale (5 items). Health locus of control is obtained from a review of references by the researcher, Sin Jae Sin (1985) translated Multidimensional health Locus of Control scale (18 items) were made by Wallston & Wallston (1976). The collected data was analysed by mean, percent, Chi-squre test, Fisher's Exact Test using the SPSS (v 6.12) and SAS program. The results of this study were as follows : 1. The characteristics of dysmenorrhea were low abdominal pain, fatigue, back pain, headache, muscle pain, diarrhea, nausea and vomiting. 2. The degree of dysmenorrhea was shown 'a few of discomfort experiment': 73%, late, leaving early and absent for school : 4.0%. 3. By means locus of control, internal health locus of control was shown 79.5% and external health locus of control was shown 20.5%. 4. The self-management of dysmenorrhea was shown 'massaging on the abdomen and bed rest' is 31.9%, 'tolerance' is 53.5%. 5. When the characteristics of dysmenorrhea was compared with demographics, low abdominal pain was significant of the number of siblings (p<.05), the family history (mother's dysmenorrhea)(p<.01) and back pain was significant of the age, family history, low abdominal pain (p<.05, p<.01, p<.01). 6. There was no significant of the locus of control. When the self-management of dysmenorrhea was compared with demographics, the age was significant (p<.05).

• 한국산림과학회지
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• 제99권1호
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• pp.131-135
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• 2010

본 연구는 P-V 곡선법을 적용하여 곰취, 곤달비, 한대리곰취의 내건성 진단과 적지재배 환경의 구명을 위해 수행되었다. 최대팽압시 삼투포텐셜 ${\Psi}_{\circ}{^{sat}}$은 곰취와 곤달비가 -0.8MPa로 한대리곰취(-0.7 MPa)보다 낮았다. 초기원형질분리점의 삼투포텐셜 ${\Psi}_{\circ}{^{tlp}}$은 곰취와 곤달비가 -0.9 MPa로 한대리 곰취(-0.8MPa)보다 낮게 나타났다. 최대탄성계수 $E_{max}$는 곰취와 곤달비가 29 MPa로 한대리곰취의 14.5MPa 보다 약 2배 가량 높았다. 초기원형질분리점에서의 상대함수율은 곰취 95%, 곤달비 93%, 한대리곰취가 94%로 비슷한 값을 나타냈다. 따라서 곰취류는 비교적 내건성이 약하고, 함수율이 매우 높은 상태에서 초기원형질분리가 일어나므로 비교적 습윤한 지역이 생육에 적합함을 알 수 있었다.

• 한국미생물·생명공학회지
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• 제33권1호
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• pp.41-50
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• 2005

Leu. mesenteroides KCCM 35471을 변이처리하고 젖산과 초산이 2:1로 함유된 유기산 조정 배지에서 screening을 하여 유기산 내성 변이균주 M-200을 얻었다. 내산성 개량균주 M-200과 야생균주 LM-W는 $10^{\circ}C\~30^{\circ}C$ 온도범위와 pH $3.5\~4.5$의 영역에서 생육 특성에 대해 실험을 행하였다. 내산성 변이균주 M-200의 경우에는 HCI로 조절한 배지에서는 $10^{\circ}C$, pH 3.5영역에서도 증식하였다. 유기산으로 조절한 배지에서는 $10^{\circ}C$, pH 3.8의 영역까지 증식하였다. 내산성 변이균주 M-200과 야생균주 LM-W를 김치에 starter로 첨가하여 $10^{\circ}C$에서 발효시킨 결과를 살펴보면, 내산성 변이균주 M-200은 김치 발효가 끝나는 시점까지 산도 0.55 이하를 유지하였다. 이는 김치의 적숙 기간을 산도가 $0.4\~0.75\%$일 때로 본다면 내산성 변이균주 M-200을 첨가한 군은 발효기간 내내 적숙기를 유지한다는 것을 알 수 있었다. 또한 이를 야생균주 LM-W를 첨가한 군과 비교해보면 가식기간이 약 3.5배 연장됨을 볼 수 있었다. 그러나 지나친 M-200의 생육으로 Lac. plantarum의 생육이 떨어지고 김치의 산도가 올라가지 못하고 신맛이 부족하여 김치의 관능이 떨어졌다. 유기산 분석에 있어서도 젖산의 생산이 대조군에 비해 발효 21일째부터는 약 절반 정도 밖에 생산하지 못하였다 따라서 starter 첨가량 조절과 다른 변이주 들과의 혼합첨가를 한다면 좋은 관능을 갖는 김치를 생산할 수 있을 것으로 생각되었다.

• Preventive Nutrition and Food Science
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• 제11권2호
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• pp.140-145
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• 2006

Seventy eight bacterial strains were isolated from several jeotgals using MRS and M 17 agar media. The probiotic properties such as tolerance of extreme growth condition, production of antimicrobial compound, production of hydrogen peroxide, and enzymatic activity of bile salt hydrolase were investigated. DHK 4, 10, 21 and 74 strains showed_a strong tolerance property against extreme conditions such as low pH and 0.5% oxgall-supplemented medium. DHK 10 and 47 strains produced hydrogen peroxide on TMB agar plate. DHK 8 and 10 strains produced antimicrobial compounds onto MRS agar against E. facalis. DHK 4, 6, 21, 29, 33, 63 and 87 strains had high activities of bile salt hydrolase. Especially, DHK 10 displayed a strong probiotic candidate; the abilities to produce the antimicrobial compound, hydrogen peroxide, and bile salt hydrolase. All these strains are assumed to be useful probiotic candidates. Among 78, twenty seven strains which have probiotic properties were tentatively identified by 16S rRNA sequencing. Among them, 7 Lactobacillus spp., 6 Leuconosotoc spp., 2 Weisella spp., 1 Pediococcus sp., 1 Staphylococcus sp., 1 Enterococcus sp. and 2 Streptococcus spp. were tentatively identified.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1521-1530
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• 2023

An α-L-rhamnosidase gene from Thermoclostridium. stercorarium subsp. thermolacticum DSM 2910 (TstRhaA) was cloned and expressed. The maximum TstRhaA activity of the protein reached 25.2 U/ml, and the molecular mass was approximately 106.6 kDa. The protein was purified 8.0-fold by Ni-TED affinity with an overall recovery of 16.6% and a specific activity of 187.9 U/mg. TstRhaA activity was the highest at 65℃ and pH 6.5. In addition, it exhibited excellent thermal stability, better pH stability, good tolerance to low concentrations of organic reagents, and high catalytic activity for p-nitrophenyl-α-L-rhamnopyranoside (pNPR). Substrate specificity studies showed that TstRhaA exhibited a high specific activity for rutin. At 60℃, pH 6.5, and 0.3 U/ml enzyme dosage, 60 g/l rutin was converted to 45.55 g/l isoquercitrin within 150 min. The molar conversion rate of rutin and the yield of isoquercitrin were 99.8% and 12.22 g/l/h, respectively. The results suggested that TstRhaA could be used for mass production of isoquercitrin.

• 한국물환경학회지
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• 제37권1호
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• pp.47-54
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• 2021

Aerobic granular sludge (AGS) can be classified as a type of self-immobilized microbial aggregates measuring more than 0.2 mm. It offers the option to simultaneously remove COD, N, and P that occur in different zones inside a granule. Also, AGS is characterized by high precipitability, treatability with high organic loading, and high tolerance to low temperature. In this study, a sequencing batch reactor inoculated with AGS (AGS-SBR) is a new advanced wastewater treatment process that was proven to grow AGS with integrated nutrient removal and low C/N ratio. A pilot plant, AGS-SBR with a capacity of 225 ㎥/d was installed at an S sewage treatment plant in Gyeonggi-do. The results of the operation showed that the water quality of the effluent indicated that the value of BOD5 was 1.5 mg/L, CODMn was 11.4 mg/L, SS was 6.2 mg/L, T-N was 13.2 mg/L, and T-P was 0.197 mg/L, and all of these values reliably satisfied an effluent standard (I Area). In winter, the T-N treatment efficiency at a lower temperature of less than 11℃ also showed reliability to meet the effluent standard of the I Area (20 mg/L or less). Analysis of microbial community in AGS showed a higher preponderance of beneficial microorganisms involved in denitrification and phosphorus accumulation compared with activated sludge. The power consumption and sludge disposal cost were reduced by 34.7% and 54.9%, respectively, compared to the domestic SBR type sewage treatment plant with a processing capacity of 1,000 ㎥/d or less.