• 한국미생물·생명공학회지
• /
• 제37권3호
• /
• pp.243-247
• /
• 2009

The usage of ethanol (EtOH)-blended gasoline (gasohol), has been increasing in recent years. EtOH has influence on the distribution and biodegradation of aromatic compounds such as BTEX (benzene (B), toluene (T), ethylbenzene (B), and xylene (X)) that are gasoline compositions. In this study, the effect of EtOH on the aerobic biodegradation of B, T and E was investigated using a BTEX and EtOH-degrading bacterium, Rhodococcus sp. EH831. The degradation rates of B in the conditions of 1:1, 1:4, and 1:0.25 mixtures with EtOH (B:EtOH, mol:mol) were ranged from $3.82{\pm}0.20$ to $5.00{\pm}0.37{\mu}mol{\cdot}g-dry$ cell wight $(DCW)^{-1}{\cdot}h^{-1}$. The degradation rate of T was the fastest in the 1:0.25 mixture ($6.63{\pm}0.06{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$), and it was the lowest in the 1:4 mixture ($4.41{\pm}0.04{\mu}mol{\cdot}DCW^{-1}{\cdot}h^{-1}$). The degradation rates of E were increased with increasing the addition amount of EtOH: The degradation rate of E was the highest in the 1:4 mixture ($1.60{\pm}0.03{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$), and the rates were $1.42{\pm}0.06$, $1.30{\pm}0.01$, and $1.01{\pm}0.30{\mu}mol{\cdot}g-DCW^{-1}{\cdot}h^{-1}$ in the 1:1, 1:0.25, 1.0 mixtures, respectively. In conclusion, the biodegradation of B, T, E by Rhodococcus sp. EH831 was not significantly inhibited by the co-existence of EtOH.

• 대한화학회지
• /
• 제67권6호
• /
• pp.407-414
• /
• 2023

The present study uses quasi-classical trajectory procedures to examine the vibrational relaxation and dissociation of the methyl and ring C-H bonds in excited methylpyrazine (MP) during collision with either N₂ or O₂. The energy-loss (-ΔE) of the excited MP is calculated as the total vibrational energy (E_T) of MP is increased in the range of 5,000 to 40,000cm^-1. The results indicate that the collision-induced vibrational relaxation of MP is not large, increasing gradually with increasing E_T between 5,000 and 30,000 cm^-1, but then decreasing with the further increase in E_T. In both N₂ and O₂ collisions, the vibrational relaxation of MP occurs mainly via the vibration-to-translation (V→T) and vibration-to-vibration (V→V) energy transfer pathways, while the vibration-to-rotation (V→R) energy transfer pathway is negligible. In both collision systems, the V→T transfer shows a similar pattern and amount of energy loss in the ET range of 5,000 to 40,000cm^-1, whereas the pattern and amount of energy transfer via the V→V pathway differs significantly between two collision systems. The collision-induced dissociation of the C-H_methyl or C-H_ring bond occurs when highly excited MP (65,000-72,000 cm^-1) interacts with the ground-state N₂ or O₂. Here, the dissociation probability is low (10^-4-10^-1), but increases exponentially with increasing vibrational excitation. This can be interpreted as the intermolecular interaction below E_T = 71,000 cm^-1. By contrast, the bond dissociation above E_T = 71,000 cm^-1 is due to the intramolecular energy flow between the excited C-H bonds. The probability of C-H_methyl dissociation is higher than that of C-H_ring dissociation.

• 폴리머
• /
• 제26권6호
• /
• pp.767-777
• /
• 2002

본 실험에서는 4관능성 에폭시 수지 (4EP)와 생분해성 modified aliphatic polyester (MAP) 블렌드의 경화 거동, 열안전성, 유변학적 특성, 그리고 기계적 특성을 살펴보았다. DSC 측정 결과, 경화 활성화 에너지 ( $E_{a}$ )는 4EP에 대한 MAP의 비율이 10 wt%로 증가함에 따라 증가하였다. 이는 4EP와 MAP 사이의 분자상호작용이 증가하였기 때문으로 사료된다. 열안정성과 관련있는 분해 활성화 에너지 ( $E_{t}$ )는 Coats-Redfern 방법을 이용하여 구하였으며 MAP의 함량비가 10에서 30 wt% 내에서 증가하였다. 이는 블렌드 시스템에서의 가교 밀도의 증가 때문으로 사료된다. 유변학적 특성은 레오미터를 이용하여 등온 조건하에서 검토하였고, 겔화 시간과 경화 온도를 이용한 Arrhenius 방정식을 적용하여 가교 활성화 에너지 ( $E_{c}$ )를 검토한 결과, $E_{a}$ 와 유사한 경향을 나타내었다. 기계적 계면특성인 파괴인성 ( $K_{IC}$ )은 시편의 semi-IPN구조 거동으로 고찰하였다.

• Genomics & Informatics
• /
• 제20권4호
• /
• pp.42.1-42.11
• /
• 2022

Breast cancer (BC) is a significant threat to female health, with both modifiable and non-modifiable risk factors. It is essential to monitor patients regularly and to raise population awareness. Increasing research also suggests that E-selectin (SELE) may increase tumor angiogenesis and the development of cancer. This study investigated SELE single-nucleotide polymorphisms (SNPs) in the following positions: rs5367T/C, rs5368C/T, rs5362T/G, and rs5362T/C. Using polymerase chain reaction, significant differences in allele and genotype frequencies were found between BC patients and controls. Position rs5368 was associated with an increased risk of BC for the CT and TT genotypes, with odds ratios (ORs) of 16.3 and 6.90 (Fisher probability = 0.0001, p = 0.005). Women with the T allele had a 19.3-fold higher incidence of BC, while allele C may be a protective allele against BC (OR, 0.05). Heterozygous genotypes at rs5367, rs5362, and rs5362 were significantly more common in BC patients, with ORs of 5.70, 4.50, and 3.80, respectively. These SNPs may be associated with the risk of BC, because the frequency of mutant alleles was significantly higher in patients (OR: 4.26, 3.83, and 4.30, respectively) than in controls (OR: 0.23, 0.30, and 0.20, respectively). These SNPs may be considered a common genotype in the Iraqi population, with the wild-type allele having a protective fraction and the mutant allele having an environmental fraction. The results also revealed a 2-fold increase in gene expression in BC patients compared to controls, with a significant effect (p = 0.017). This study's findings confirm the importance of SELE polymorphisms in cancer risk prediction.

• 전자공학회논문지A
• /
• 제30A권4호
• /
• pp.1-10
• /
• 1993

This paper presents the designing/manufacturing scheme of the diplexer for satellite transponder which is composed of 2-channel bandpass filters, coupled with E-plane T-junction, having symmetrical waveguide E-plane step discontinuity structures. The 2-channel bandpass filters of the diplexer are designed by the scheme of connecting ${\lambda}_{g}$/2 shunt stub to the waveguide E-plane, playing the role of heat sinks without attaching a special heat sinks and to give the profitable productivity and allow the low-cost manufacturing at mass production, tuning screws are eliminated which have been used to compensate the operating characteristics of manufactured filters. The 2 channel bandpass filters of manufactured 14/12 GHz diplexer for domestic Ku-band satellite transponder have the return loss of 25 dB, insertion loss of 0.3 dB in passband, and below-50 dB of stopband characteristics (T$_{x}$ : f$_{o}{\pm}$250 MHz, R$_{x}$ : f$_{o}{\pm}$220 MHz) at room temperature.

• 대한방사선기술학회지:방사선기술과학
• /
• 제26권2호
• /
• pp.57-61
• /
• 2003

두정부 백질 물질 NAA, Choline(Cho), Creatine(Cr), choline chloride, glutamin 등으로 자체 제작한 phantom을 이용하여 고 자장(4.7T)과 중자장(1.5T)에서의 신호강도 대 잡음비, 스펙트럼 분해능을 알아 볼 수 있는 선폭과 $T_2$, 그리고 $T_E$값의 변화에 따른 각 대사물질의 변화별 스펙트럼 등을 구하여 이론적인 정보와 실제적인 정보와의 차이를 알아보고자 한다. 이용된 기기는 Bruker Biospec 4.7T와 1.5T GE SIGNA를 이용하여 MRS의 결과를 얻었다. 관심영역에서 얻은 정보에서 분광 peak의 면적을 구하였다. 통계처리는 Microsoft사의 Excel program내에 있는 통계 package를 이용하였다. 중자장(1.5T)과 고자장(4.7T)에서의 각각의 대사물질의 스펙트럼을 얻어 본 결과 자장의 균일도와 SNR과 $T_2$값의 차이가 이론적인 값보다는 직선성을 보이지 않았다. 1.5T에서의 선폭은 Cho, Cr, NAA 순서로 $5.30{\pm}1.07,\;4.81{\pm}0.14,\;5.49{\pm}0$, 이에 반해 4.7T에서는 $9.14{\pm}0.55,\;8.87{\pm}0.67,\;9.65{\pm}0.56$ Hz 값이 나왔다. 평균 SNR은 NAA의 물질의 경우를 3회 측정하였는데 그 평균치는 63%의 증가를 보였다. $T_E$ 변화로 스펙트럼을 분석했을 때 $T_E=60ms$일 때 가장 SNR이 좋은 값을 보였고 $T_E=135ms$일 때 가장 낮은 값을 나타나 보였다. 두정부 백질 물질 Phantom을 제작하여 자장의 강도 즉 중자장(1.5T)과 고자장(4.7T)에 따라 분석하게 되었는데 고자장의 영역으로 갈수록 분해능, SNR은 좋아져 보이나 자장의 세기가 커질수록 이론적인 수치보다는 상당히 적은 증가를 보이고 있다는 것을 이 연구를 통해 알게 되었다.

• 한국식생활문화학회지
• /
• 제30권3호
• /
• pp.362-369
• /
• 2015

This study compared the nutritional composition and antioxidative activities of different parts (aerial part and root) of Taraxacum coreanum and Taraxacum officinale. To identify the nutrient composition of different parts of Daedelion species, nutrient contents were analyzed. Crude ash, protein, and fat contents of T. coreanum and T. officinale were higher in the aerial part compared to the root. There was no significant difference in crude ash, protein, or carbohydrate content of the aerial part depending on the Daedelion species. Aerial part contents of vitamin A, E, and C were significantly higher in T. coreanum than T. officinale. The K content of the aerial part of T. coreanum and T. officinale was highest, although there was no significant difference among Daedelion species. Contents of oxalic acid, citric acid, and acetic acid in the aerial part of T. coreanum were highest. Contents of total polyphenols, total flavonoids, and DPPH radical scavenging activity of the aerial part were significantly higher in T. coreanum than T. officinale. In conclusion, the aerial part of T. coreanum and T. officinale could be used as antioxidative functional food sources.

• 한국자기학회지
• /
• 제4권1호
• /
• pp.52-55
• /
• 1994

HD 기체에 대하 수소 및 중수소 원자핵 스핀-격자 완화시간 $T_{1}(H)$와 $T_{1}(D)$가 측정되었다. 실험데이타는 온도 30 K < T < 313 K 및 압력 0.67 atm < P < 1.92 atm에서 측정되어졌다. 핵자기공명 주파수는 각각 수소원자핵에 대해서 358.012 MHz였고 중수소원자핵에 대해서는 54.958 MHz였다. 측정된 $T_{1}(H)$와 $T_{1}(D)$의 비로부터 분자스핀 연산자들인 $J_{z}$와 ${3J_z}^{2}-J(J+1)$에 관련된 상관시간의 비 ${\tau}_{1}/{\tau}_{2}$의 값이 얻어졌다. J = 1 상태에서의 원자핵 스핀-격자 완화시간이 온도의 함수로서 $T^{0.25}$에 비례하는 것이 관측되었다.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제30권2호
• /
• pp.109-129
• /
• 2023

In this paper, we introduce a second order linear differential operator ^T□: C^∞ (M) → C^∞ (M) as a natural generalization of Cheng-Yau operator, [8], where T is a (1, 1)-tensor on Riemannian manifold (M, h), and then we show on compact Riemannian manifolds, divT = divT^t, and if divT = 0, and f be a smooth function on M, the condition ^T□ f = 0 implies that f is constant. Hereafter, we introduce T-energy functionals and by deriving variations of these functionals, we define T-harmonic maps between Riemannian manifolds, which is a generalization of L_k-harmonic maps introduced in [3]. Also we have studied fT-harmonic maps for conformal immersions and as application of it, we consider fL_k-harmonic hypersurfaces in space forms, and after that we classify complete fL₁-harmonic surfaces, some fL_k-harmonic isoparametric hypersurfaces, fL_k-harmonic weakly convex hypersurfaces, and we show that there exists no compact fL_k-harmonic hypersurface either in the Euclidean space or in the hyperbolic space or in the Euclidean hemisphere. As well, some properties and examples of these definitions are given.

• 한국식품영양과학회지
• /
• 제40권10호
• /
• pp.1384-1390
• /
• 2011

본 연구에서는 감국 에탄올 추출물이 조골세포의 증식 및 분화에 미치는 영향을 분석하여 골다공증 관련 식물성 에스트로젠으로써의 이용 가능성을 확인하고자 하였다. 감국 에탄올 추출물은 30～100 ${\mu}g/mL$ 농도 범위에서 조골세포의 증식을 유의적으로 증가시켰으며, 100 ${\mu}g/mL$ 농도에서 대조군 대비 최대 122% 세포성장을 나타내었다. 이러한 세포증식 유도는 estrogen antagonist인 tamoxifen 처리 시 상쇄되어 estrogen 유사효과에 의한 것으로 사료되었다. MC3T3-E1 세포의 분화에 미치는 영향을 살펴보고자 대표적 분화지표인 ALP 효소활성, collagen 함량, mineralization 수준을 측정한 결과, 10, 30 ${\mu}g/mL$ 농도에서 ALP 활성의 유의적 증가와 200 ${\mu}g/mL$ 농도에서 collagen 함량과 mineralization의 유의적인 증가를 확인하였으며, ALP 활성, collagen 함량 모두 tamoxifen 처리에 의해 증가 효과가 상쇄되어 estrogen 유사작용에 의한 것으로 사료된다.