• 미생물학회지
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• 제9권4호
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• pp.145-148
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• 1971

Mitochondria were isolated from Chlorella cells effects of cation on solute permeability of mitochondrial membrane were investigated using P$^{32}$ as a tracer. It was strikingly increased uptake of phosphate for NaCl, KCl, while evidently decreased phosphate uptake of mitochondrial membrane for $MgCl_2$, $CaCl_2$. This consider that uptake of monovalent cation were increased, but uptake of divalentcation were decreased for permeability of mitochondrial membrane as if the permeability of protoplasmic membrane.

• Membrane and Water Treatment
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• 제4권3호
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• pp.203-214
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• 2013

Laboratory tests were performed to determine the efficiency of dye solution desalination by electrodialysis. The study involved anionic dye and mineral salt recovery by obtaining two streams from a salt and dye mixture - dye-rich solution and salt solution. A standard anion-exchange and cation-exchange membranes or monovalent selective anion-exchange membranes were used in the ED stack. It was found that the separation efficiency was strongly dependent on the dye molecular weight. The best results for standard ion-exchange membranes were achieved for the desalination of Direct Black solution. Furthermore, the obtained results implied that the application of monovalent selective anion-exchange membranes improved the recovery of dye and salt solutions - the dye concentration in the diluate remained constant irrespective of the molecular weight of anionic dyes, whereas the salt recovery remained very high (99.5%).

• Computers and Concrete
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• 제17권1호
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• pp.53-66
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• 2016

Currently, most of the investigations on chloride diffusion were based on the experiments and simulations concerning single cation type chlorides. Chloride diffusion associated with dual or multi cation types was rarely studied. In this paper, several groups of diffusion experiments are conducted using chloride solutions containing single, dual and multi cation types. A multi-ionic model is also proposed to simulate the chloride diffusion behavior in the experimental tests. The MATLAB software is used to numerically solve the nonlinear PDEs in the multi-ionic model. The experimental and simulated results show that the chloride diffusion behavior associated with different cation types is significantly different. When the single cation type chlorides are adopted, it is found that the bound rates of chloride ions combined with divalent cations are greater than those combined with monovalent cations. When the dual/multi cation type chlorides are adopted, the chloride bound rates increase with the $Ca^{2+}/Mg^{2+}$ percentage in the source solutions. This evidence indicates that the divalent cations would markedly enhance the chloride binding capacity and reduce the chloride diffusivity. Moreover, on the basis of the analysis, it is also found that the complicated cation types in source solutions are beneficial to reducing the chloride diffusivity.

• 대한화학회지
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• 제38권7호
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• pp.529-532
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• 1994

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.71-71
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• 2012

Chemically modified graphene has been great interest for the application of printed electronics using solution prossesable technique. Here, we demonstrate a large area graphene exfoliation method with fewer defects on the basal plane by application of shear stress in solution to obtain high quality reduced graphene oxide (RGO). Moreover, we introduce a novel route to preparing highly concentrated and conductive RGO in various solvents by monovalent cation-${\pi}$ interaction. Noncovalent binding forces can be induced between a monopole (cation) and a quadrupole (aromatic ${\pi}$ system). The stability of this RGO dispersion was more sensitive to the strength of the cation-${\pi}$ interactions than to the cation-oxygen functional group interactions. The RGO film prepared without a post-annealing process displayed superior electrical conductivity of 97,500 S/m. Our strategy can facilitate the development of large scalable production methods for preparing printed electronics made from high-quality RGO nanosheets.

• 광물과 암석
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• 제35권3호
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• pp.345-353
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• 2022

본 연구는 합성 모데나이트(Na_6.6Al_6.6Si_41.4O₉₆·20.4H₂O, Na-MOR)를 이용한 다양한 중금속의 포획 연구를 하기 위한 기초 단계로, 고분해능 X-선 분말 회절을 이용하여 치환체의 격자상수 및 부피 변화를 이해하기 위한 목적으로 실험을 진행하였다. 열중량 분석법(Thermogravimetric analysis, TGA)으로 측정한 결과, 1가 양이온 치환체(Cs-MOR, Na-MOR)는 단위포 당 19.4, 20.4개의 물분자가 존재하였으며, 2가 양이온 치환체(Pb-MOR, Sr-MOR, Cd-MOR)는 단위포 당 21, 23.1, 23.2개가 존재하는 것을 확인하였다. 측정한 모든 물질은 사방정계에 속하는 Cmcm의 공간군을 가지는 것으로 확인할 수 있었다. 치환 전 물질인 Na-MOR과 비교했을 때, 치환체의 (110)면과 (200)면의 회절강도가 명확하게 변화하였으나, 전체적인 피크의 위치는 거의 유사하게 나타나는 것을 확인할 수 있었다. 또한 Na-MOR에서는 확인이 되지 않았던 (220)면의 피크가 Pb-, Cd-, Sr-MOR에서 뚜렷하게 관찰되었다. 이를 통해서 양이온 치환에 따른 원자들의 분포 변화가 주로 ab-평면상에서 나타나지만, 격자상수의 변화는 미세할 것으로 짐작할 수 있었다. Whole profile fitting 방법을 사용하여 치환된 모데나이트의 미세한 격자상수의 변화를 관찰하였다. 치환체의 격자상수 및 격자부피의 변화는 치환된 양이온의 반경 및 전하수에 따라 서로 다른 경향성을 보였다. 1가 양이온의 경우, 이온반경이 증가할수록 a-축의 길이는 증가하지만, 반면에 b- 및 c-축의 길이는 감소하였다. 2가 양이온의 경우, 이온반경이 증가할수록 대체적으로 a-축의 길이가 감소하고, b- 및 c-축의 길이는 증가하였다. 격자부피는 1가 또는 2가 양이온 치환체들이 각각 독립된 경향성을 가지며, 이온반경에 따라 증가하는 것을 확인할 수 있었다.

• Journal of Applied Biological Chemistry
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• 제43권1호
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• pp.18-24
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• 2000

A one-dimensional transport of displacing monovalent ion, $A^+$, and a trivalent ion being displaced, $B^{3+}^ in a porous exchange system such as soil was approximated using the Crank-Nicolson implicit finite difference technique and the Thomas algorithm in tandem. The variations in the concentration profile were investigated by varying the ion-exchange equilibrium constant (k) of ion-exchange reactions, the influent concentrations, and the cation exchange capacity (CEC) of the exchanger, under constant flux condition of pore water and dispersion coefficient. A higher value of k resulted in a greater removal of the native ion, behind the sharper advancing front of displacing ion, while the magnitude of the penetration distance of $A^+$ was not great. As the CEC increased, the equivalent fraction of $B^{3+}^ initially in the soil was greater, thus indicating that a higher CEC adsorbed trivalent cations preferentially over monovalent ions. Mass balance error from simulation results was less than 1%, indicating this model accounted for instantaneous charge balance fairly well.

• 생명과학회지
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• 제14권1호
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• pp.17-20
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• 2004

대장균 트립토판 합성효소의 $\beta$반응의 빠른 속도 반응에 일가 양이온의 영향을 D56N과 D56G 잔기치환체를 대상으로 조사하였다. 일가 양이온을 처리하였을 때 생성되는 중간반응 생성물의 생성과 분해 속도가 영향을 받았다. 56번 자리 잔기치환체도 야생형에 비해 반응의 중간산물의 생성과 분해에 있어 모두 느린 속도를 보여주고 있다. 이들 잔기 치환체에 미치는 일가 양이온의 영향 또한 달라졌다. 이 결과는 대장균의 효소에서도 56번잔기가 이소조절에 관여하고 있고, 이 과정에서 일가 양이온들이 이소조절 리간드역할을 수행하는 것을 보여준다.

• International Journal of Industrial Entomology and Biomaterials
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• 제27권2호
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• pp.326-328
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• 2013

Sericin undergoes gelation by the structural transition from random coil to b-sheet transition. In the present study, the gelation time of sericin solution was investigated in the presence of NaCl, KCl and $CaCl_2$. The addition of salts delayed the gelation time, and $CaCl_2$ had the most pronounced effect, which delayed about 8 h at maximum. The gelation time increased with the concentration of salt. The transition of secondary structure of sericin was retarded in the presence of salt. The effect of salts on the gelation time of sericin might be due to the solvation effect of relevant cation.

• 한국세라믹학회지
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• 제42권6호
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• pp.371-376
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• 2005

Phosphate glasses were prepared by melting quenching process, and glass formation and dissolution properties were studied. The glass forming region in the $K_2O-CaO-P_2O_5$ system is quietly agreed with the report by Mazurin OV et al. with $M_2O-M'O-P_2O_5$ system (M : monovalent cation, M'divalent cation). Conditionally these glasses have solubility from absorbing the moisture or water and then release elements with trace elements, and the thermal and chemical properties were controllable by the $CaO,\;K_2O,\;P_2O_5$ contents. In the abnormal glass properties, this paper showed the possibility the present glasses can be a good candidate for one component of the slow released agriculture fertilizer.