• 한국잠사곤충학회지
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• 제39권2호
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• pp.169-173
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• 1997

The behavior of tyrosine(Tyr.) residue of Bombyx mori silk fiber from yellow fluorescent cocoon has been examined for the dependence of pH in aqueous silk solution under the presence of orange II salt. Through the peak separation of angular dependence of spectral pattern of 15N-Tyr. and [1-13C]-Tyr. between the fiber axis and the molecular bond direction, N-H bond in fiber as well as the orientation distribution around the fiber axis were analyzed. Also, and sericin component was obtained from these angular dependence of oriented spectral pattern. The pH dependence of the 13C NMR chemical shift of B. mori silk fibroin was examined in aqueous solution in the presince of orange II are broad at pH$\geq$7.0. However, these become sharper at pH$\geq$8.0 and remain sharp at higher pH. In these higher pH range, a chemical shift change occurs due to the deprotonation of the Tyr. side group of fibroin. At higher pH. such a hydrophobic cluster is destroyed because of the electrostatic interaction according to the deprotonation of the Tyr-OH group.

• 한국작물학회지
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• 제45권2호
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• pp.139-142
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• 2000

The experiment was carried out to study the variations and geographical distribution of $\beta$-amylase isozyme by isoelectric focusing (IEF) within Korean, Chinese and Japanese soybean land races. In pH 3-10 gel of IEF, the amylase of soybean accessions was separated into low pI group isozymes (TEX>${$Sp_1$}^b$) and high pI group isozymes(${$Sp_1$}^a$). In pH4-6.5 gel, isoelectric points were at 5.07, 5.15, 5.25, 5.40, and 5.94, and h, j, and k bands also were found. The distribution of Sp$_1$$^{a}$ allele (high pI type) was 29.3% in soybean accessions from Korea, 10.1 % in those from China, and 6.9% in Japanese accessions. The percentage of ${$Sp_1$}^a$) allele was the highest in soybean accessions from Kyungsang province (35 %) in Korea, then central China (32 %) in China, and Honshu (10%) in Japan.

• 한국토양비료학회지
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• 제36권4호
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• pp.200-209
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• 2003

우리나라의 몇 가지 경작지 토양을 대상으로 하여 카드뮴의 토양-물 분배계수를 측정하였다. 토양에 대한 카드뮴의 흡착은 토양 영구전하에 의한 이온교환 반응과 토양 가변전하에 의한 표면착물 반응의 합으로 표현할 수 있으며, 이때 카드뮴의 분배계수는 pH와 이론적 으로 다음의 상관관계를 갖는다. $log\;K_d=a_0+b_0{\times}pH$ (단, $a_0$와 $b_0$는 상수). 토양에 대한 카드뮴의 회분형 흡착실험에서 분배계수는 토양의 pH 변화에 따라 정으로 증가하였다. 그러나 pH 3.5 이하 및 pH 8.5 이상에서는 측정한 분배계수가 위의 식으로 예측한 값보다 낮게 나타났다. 이는 산성 조건에서는 알루미늄의 용해가 일어나고, 알칼리 조건에서는 토양 유기물이 용해되어 용액 내 카드뮴의 분배에 영향을 미쳤기 때문으로 판단된다. 각각의 토양에 대한 유기물 함량을 이용 해 표준화한 분배계 수 ($K_{d-om}$)에 의하여 위 식의 상관계수는 $0.52^{**}$에서 $0.70^{**}$으로 상승되어 예측력을 개선할 수 있었다. 또한, 실제 오염토양에서 측정한 분배계수와 표준화한 함수식을 이용하여 예측한 분배계수 사이에는 고도의 유의적인 상관관계 ($r^2=0.68^{**}$)를 보였다.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2841-2848
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• 2010

Quasiclassical trajectory (QCT) method has been used to investigate stereodynamics information of the reaction $O(^1D)+H_2{\rightarrow}\;OH$+H on the DK (Dobbyn and Knowles) potential energy surface (PES) at a collision energy of 23.06 kcal/mol, with the initial quantum state of reactant $H_2$ being set for v = 0 (vibration quantum number) and j = 0-5 (rotation quantum number). The PDDCSs (polarization dependent differential cross sections) and the distributions of P($\theta_r$), P($\phi_r$), P($\theta_r$, $\phi_r$) have been presented in this work. The results demonstrate that the products are both forward and backward scattered. As j increases, the backward scattering becomes weaker while the forward scattering becomes slightly stronger. The distribution of P($\theta_r$) indicates that the product rotational angular momentum j' tends to align along the direction perpendicular to the reagent relative velocity vector k, but this kind of product alignment is found to be rather insensitive to j. Furthermore, the distribution of P($\phi_r$) indicates that the rotational angular momentum vector of the OH product is preferentially oriented along the positive direction of y-axis, and such product orientation becomes stronger with increasing j.

• 센서학회지
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• 제10권2호
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• pp.118-124
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• 2001

입자들이 용액에 녹아있을 때 pH에 따라서 다른 zeta-potential을 가지게 되며, 이것은 입자의 분산상태에 영향을 주게 된다. NO 센서에서 $WO_3$ 입자의 크기는 감도에 큰 영향을 끼치므로 Sol-Coprecipitation법에 의한 $WO_3$ 센서 제조 시에 $WO_3$ precursor 상태에서의 pH의 영향을 알아보았다. 먼저 $WO_3$ precursor의 전기적 포텐셜을 측정하여 pH가 2에서 7로 변함에 따라 mobility가 증가하여 7일 때에 가장 큰 분산도를 가진 것을 알 수 있었고, 이는 powder 제조 후 입도 분석, 감지막의 XRD peak, 표면사진으로부터 확인 할 수 있었다. 결과적으로 감도 특성에도 영향을 끼쳐 pH=7에서 제조한 센서가 다른 pH에서 제조한 센서보다 감도가 우수한 것으로 나타났다.

• 대한지리학회지
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• 제38권1호
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• pp.1-15
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• 2003

본고는 강원도 양구군 대암산 정상부(1,280m)에 위치한 우리나라 대표적 고층습원인 용늪의 늪 환경을 유지시키기 위해 실시된 지하수 수질 기초조사 결과이다. 용늪의 지하수 수질 특성을 파악하기 위하여 지하수온과 pH, 전기전도도의 변화값이 2000년 7월부터 12월까지 6개월에 걸쳐 29개소의 관측정에서 조사되었다. 용늪의 건조화가 진행되고 있는 지점의 수질 값은 다른 지점과 비교할 때 수질항목별 각월의 일정한 분포 범위를 벗어나고 있는 특성을 보인다. 용늪내 월별 지하수온은 매일 평균수온과 비교할 때 대개 2$^{\circ}C$ 정도의 편차를 보이고 있으며, 용늪의 지하수위가 높아질수록 지하수온도 증가하는 패턴을 보인다. 용늪 지하수의 pH는 대개 5.0 에서 6.0 사이의 값을 갖고 있으나 국지적으로는 4.0 미만의 강산성을 띠고 있는 경우도 있다. 나지에서 측정된 지하수 pH 값은 다른 지점의 pH 값보다 높게 나타나고 있다. 용늪의 전기전도도값은 지하수위가 높을수록 증가하는 경향을 보인다. 그러나. 지하수의 전기전도도값은 지표수의 전기전도도값과 계절별로 서로 다른 변화를 갖는다. 용늪내 지하수의 pH와 전기전도도간에는 정비례 관계를 갖고 있으며. 수온과 pH. 수온과 전기전도도는 각각 계절별로 일정한 범위내의 값을 갖는 것으로 조사되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4405-4408
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• 2016

Background: To investigate the characteristics of allelic distribution of IGF2 and H19 gene polymorphisms in molar tissues compared to normal placentas. Materials and Methods: Forty-nine specimens of molar tissues as well as 100 control normal placental tissues, delivered on the same days, were collected. Polymerase chain reaction (PCR) with restriction fragment length polymorphism (RFLP) on 2% agarose gel electrophoresis was conducted to determine the allelic distribution. The ApaI polymorphism within exon 9 of IGF2 and the RsaI polymorphism within exon 5 of H19 were employed to identify the allelic distribution of the IGF2 and H19 genes, respectively. Then the data for these genes in the molar and normal placenta tissues were compared. Results: The allelic distribution of IGF2 genes found in molar tissue were 21 (42.9%) aa (undigested), 10 (20.4%) ab (heterozygous) and 18 (36.7%) bb (digested), while in normal placenta tissue the values were 22 (22%) aa, 51 (51%) ab, and 27 (27%) bb. The allelic distribution of H19 in molar tissues was 8 (16.2%) aa (undigested), 8 (16.3%) ab (heterozygous) and 33 (67.4%) bb (digested) and in normal placental tissue was 16 (16%) aa, 36 (36%) ab and 48 (48%) bb in normal placenta tissue. These results were significantly different with P values of 0.001 and 0.037 for the allelic distribution of IGF2 and H19, respectively. Conclusions: Molar tissues showed significant differences of allelic distribution of IGF2 and H19 from normal placenta tissues.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1041-1046
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• 2019

In terms of long-term safety for radioactive waste disposal, the anionic iodide (I-129) with a long half-life ($1.6{\times}10^6yr$) is of a critical importance because this radionuclide migrates in geological media with limited interactions. Various studies have been performed to retard the iodide migration. Recently, some minerals that are likely generated from waste container corrosion, have been suggested to have a considerable chemical interaction with iodide. In this study, chalcocite and mackinawite were selected as candidate minerals for underground corrosion materials, and an iodide sorption experiment were carried out. The experiment was performed under anoxic and alkaline conditions and the pH effects on the iodide sorption were investigated in the range of pH 8 to 12. The results showed that both minerals demonstrated a noticeable sorption capacity on iodide, and the distribution coefficient ($K_d$) decreased as the pH increased in the experimental condition. In addition, when the alkalinity increased higher than a pH of 12, the sorption capacity of both minerals decreased dramatically, likely due to the competition of hydroxy ions with the iodide. This result confirmed that chalcocite was an especially good sorbing media for iodide under alkaline conditions with a pH value of less than 12.

• Journal of Magnetics
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• 제1권1호
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• pp.51-54
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• 1996

The effects of additional P-doping on the magnetic properties, thermal stability and cation distribution of Co-doped ${\gamma}-{Fe_2} {O_3}$have been investigated by means of magnetic annealing and measurements with vibration sample magnetometer and torque magnetometer. It is found that the P-doping promotes the coercivity and its magnetic-thermal stability, which may be attributed to increase of the cubic magneto-crystalline anisotropy constant, $K_1$ and the activation energy, E, for cation rearrangement, respectively. The cation distribution of P and Co-substituted iron oxide was calculated from the variation of the saturation magnetization with P-doping on the basis of the Neel model. It was found that the most of P ions in the iron oxides occupied the B-site of spinel lattice.

• 전기학회논문지
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• 제56권3호
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• pp.465-471
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• 2007

The one step type pole and two step type pole are used in KEPCO's distribution system. The neutral current increases in three-phase four-wire distribution system due to unbalanced load. Usually, power line and communication line are installed at contiguity by effect of topography in Korea. To this end, the damages such as electrostatic induction, electromagnetic induction and harmonic induction generated by induced voltage and current are occured in power line and communication line. This paper calculates the neutral current in KEPCO's distribution system using EMTP by composing various simulated conditions. Also, these results are verified by vector analysis.