• Environmental Engineering Research
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• 제14권4호
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• pp.220-225
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• 2009

The water quality in eutrophic lakes is affected by serious problems, such as abnormal increasing of Cyanobacteria. The purpose of this study was to investigate the possibility of a modified flotation system using a hybrid technique formed by chemical compounds and an electrostatic bridge. Therefore, experiments using the hybrid technique were performed to measure the zeta potential value on the phytoplankton surface and the removal efficiencies of phytoplankton, ammonia nitrogen, nitrate nitrogen and phosphoric acid. The results were as follows: Firstly, the zeta potential of M.aeruginosa was observed to approach charge neutralization due to adhesion of magnesium hydroxide precipitate on the phytoplankton surface in the pH range 10.5 to 11. Secondly, the concentration of chlorophyll-a decreased from about 150 to 20${\mu}g$g/L, with a maximum removal efficiency of 84% due to coagulation with pH values higher than 10. Thirdly, the N$H_4$-N concentration was observed to decrease from 0.62 to 0.54mg-N/L (13%), and the P$O_4$-P concentration, which is a limiting factor to the formation of algae blooms, decreased from 0.27 to 0.02mg-P/L (92%). These findings suggest that the modified flotation system can be applied for the purification of the raw water of numerous lakes containing high phytoplankton populations and elevated pH.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2617-2620
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• 2009

Using Coulomb-Yukawa like correlated interaction potentials of integer and noninteger indices the series expansion formulae in terms of multicenter overlap integrals of three complete orthonormal sets of ${\psi}^{\alpha}$‒exponential type orbitals and linear combination coefficients of molecular orbitals are established for the potential of electrostatic field produced by the charges of molecule, where $\alpha$ = 1, 0, ‒1, ‒2,${\cdots}$. The formulae obtained can be useful for the study of interaction between atomic--molecular systems containing any number of closed and open shells when the ${\psi}^{\alpha}$‒exponential type basis functions and Coulomb-Yukawa like correlated interaction potentials are used in the Hartree-Fock-Roothaan and explicitly correlated approximations. The final results are valid for the arbitrary values of parameters of correlated interaction potentials and orbitals. As an example of application, the calculations have been performed for the potential energy of interaction between electron and molecule $H_2O$ using combined Hartree-Fock-Roothaan equations suggested by the author.

• 한국염색가공학회지
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• 제1권1호
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• pp.19-25
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• 1989

In past, dye diffusion and dyeing rate in fibers have been emphasized in dyeing phenomena. However, in the light of the properties of colloids in the surface of disperse phase and dispersion, there exist specific characters such as adsorption or electric double layer, which seems to play important roles in determining the physiochemical properties in the dyeing system. Electrostatic bonding, hydrogen bonding and Van der Waals adsorption are common in dyeing as well as covalent bonding. Particularly, electrostatic bonding is premised on the existance of ionic radicals in fibers. The present study was aimed to clarify the electrokinetic phenomena of dyeing through the role of electric double layer by ion in amphoteric fibers with different ionic effects under different pH. Spectrophotometric analysis method was used to compare dyeing condition of surface, which can be detected by electrokinetic phenomena and the inner of fibers after deceleration of dyed fibers. Nylon and wool, the typical amphoteric fibers were dyed with monoazo acid dyes such as C.I. Acid Orange 20, and C.I. Acid Orange 10. Various combinations were prepared by combining pH, temperature and dye concentration, in order to generate streaming electric potential which were measured by microvolt meter and specific conductivity meter. The results were transformed to zeta potential by Helmholtz-Smoluchowski formular and to surface electric charge density by Suzawa formular, surface dye amount, and effective surface area of fibers. The amount of dyes of inner fibers were also measured by the Lambert-Beer’s law. The main results obtained are as follows. 1. By measuring zeta pontential, it was possible to detect the dyeing mechanism, surface charge density, surface dye amount and effective surface area concerning dye adsorption of the amphoteric fibers. 2. Zeta pontential increases in negative at low pH and high dye concentration in the process of dyeing. This implied that there existed ionic bond formation in the dyeing mechanism between acid dyes and amphoteric fibers. 3. Dibasic acid dye had little changing rate in zeta potential due to the difference in solubility of dye and in number of dissociated ions per dye molecule to bond with amino radicals of amphoteric fibers. The dye adsorption of mono basic acid dye was higher than that of dibasic acid dye. 4. The effective surface areas concerning dyeing were $6.3E+05\;cm^2/g$ in nylon, $1.6E+07\;cm^2/g$ in wool fiber being higher order of wool then nylon.

• 한국염색가공학회지
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• 제17권1호
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• pp.7-13
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• 2005

Continuous and intense UV irradiation on PTT film using two types of UV bulbs at different irradiation power level was carried out to modify surface characteristics of the film including zeta potential, wettability, surface energy, and dyeability. ESCA analysis of the irradiated film showed higher O/C ratio than the untreated film indicating photooxidation of outer surface layer. ATR analysis showed that the ester bonds were broken and some new groups were produced such as carboxylic acid, phenolic hydroxy, and other esters, implying that ester bonds of PTT was responsible for the observed photooxidation effect. The surface of the treated PTT film became more hydrophilic and wettable to water, coupled with increased surface energy. Polar component of the surface energy increased and nonpolar component decreased with increasing irradiation energy. The treatment also decreased zeta potential of the modified surface and nanoscale roughness increased with increasing irradiation. The dyeability of the treated films to catonic dyes was significantly improved by electrostatic and polar interaction between dye molecules and the anionic film surface. The UV irradiation seems to be a viable polymer surface modification technology, which has advantages such as no vacuum requirement and continuous process unlike plasma treatment.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1571-1576
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• 2016

Alteration of the acetylation status of chromatin and other non-histone proteins by HDAC inhibitors has evolved as an excellent epigenetic strategy in treatment of cancers. The present study was sought to identify compounds with positive pharmacological profiles targeting HDAC1. Analogues of Vorinostat synthesized by Cai et al, 2015 formed the test compounds for the present pharmacological evaluation. Hydroxamte analogue 6H showed superior pharmacological profile in comparison to all the compounds in the analogue dataset owing to its better electrostatic interactions and hydrogen bonding patterns. In order to identify compounds with even better high affinity and pharmacological profile than 6H and Vorinostat, virtual screening was performed. A total of 83 compounds similar to Vorinostat and 154 compounds akin to analogue 6H were retrieved. SCHEMBL15675695 (PubCid: 15739209) and AKOS019005527 (PubCid: 80442147) similar to Vorinostat and 6H, were the best docked compounds among the virtually screened compounds. However, in spite of having good affinity, none of the virtually screened compounds had better affinity than that of 6H. In addition SCHEMBL15675695 was predicted to be a carcinogen while AKOS019005527 is Ames toxic. From, our extensive analysis involving binding affinity analysis, ADMET properties predictions and pharmacophoric mappings, we report Vorinostat hydroxamate analogue 6H to be a potential candidate for HDAC inhibition in treatment of cancers through an epigenetic strategy.

• 한국화재소방학회논문지
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• 제25권3호
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• pp.107-112
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• 2011

본 연구에서는 대전방지필름 제조공장에서의 화재위험성 등을 고찰하였다. 대전방지필름 제조공정에서는 에탄올, 메탄올, 이소프로필알콜 같은 인화점이 낮은 용제가 사용되며 이들 용제의 최소점화에너지는 0.16 mJ~0.65 mJ로 낮은 방전에너지에도 쉽게 착화할 위험성이 있다. 제조공정 각 부분에서 발생하는 정전기 전위를 측정한 결과, 합지 과정의 필름에서 17kV~20kV의 전위가 측정되었다. 이는 화재 폭발 방지를 위한 부도체의 대전 목표 값인 5kV를 초과하는 것이다. 따라서 대전방지필름 제조공장에서 정전기 방전에 의한 화재위험성이 높다는 것을 알 수 있었다.

• 공업화학
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• 제4권2호
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• pp.409-415
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• 1993

Lippin cott/schroeder 포텐샬 함수는 O-H---O와 같은 수소결합 시스템에 응용되고, 좋은 데이터를 주기 위하여 약간 수정된다. 이 모델의 사용은 Van der Waals 반발력과 정전기적 상호작용을 표현하는 항들을 요구하며, 이들 항들은 평형조건으로부터 결정된다. 이 간단한 모델을 사용하므로서, 주파수이동과 수소결합 형성의 엔탈피 관계는 직선이 될 것으로 예상되며, 이것은 문헌에 있는 실험적 결과와 일치한다는 것을 보여준다.

• 한국염색가공학회지
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• 제13권2호
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• pp.114-119
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• 2001

Four kinds of neutral sodium salts with different anions, NaF, NaCl, NaBr, and NaI, were added to the dye bath to accurately understand the effect of anions on the reactive dyeing of silk with C. I. Reactive Black 5. The sodium cation towered the negative surface potential of the silk and increased the dye-uptake on fille fabric as reported previously. However, because of the discrepancy in the anions'inhibition power from cation's lowering: the surface negative potential the amount of the dye on the silk fiber was different from each other in the order of $F^->Cl^-> Br^-I^-$. The activation energy(E$_{a}$) lot the dyeing was in the order of $F^->Cl^-> Br^-I^-$ but the dye-uptake on the fabric and the activation free energy$(\Delta{G}^*)$, the real energy barrier fort the reaction, were in the order of $F^->Cl^-> Br^-I^-$ because the strength of the interaction of the anions with sodium cations was the salute as the order of the latter. In other words F$^{[-1000]}$ exerted the weakest electrostatic force on $Na^+$ and competed with the dyestuff anions least of all. The decrease in $\Delta{S}^*$ may be due to the looesly bonded activated complex of dyestuff anions, sodium cations and fiber molecules at transition state. It was clarified from the Brёnsted equation that sodium salts with different anions also had fille ionic strength effect and the specific salt effect on the reactive dyeing.g.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1043-1046
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• 2013

Prediction of physicochemical properties of organic molecules is an important process in chemistry and chemical engineering. The MSEP approach developed in our lab calculates the molecular surface electrostatic potential (ESP) on van der Waals (vdW) surfaces of molecules. This approach includes geometry optimization and frequency calculation using hybrid density functional theory, B3LYP, at the 6-31G(d) basis set to find minima on the potential energy surface, and is known to give satisfactory QSPR results for various properties of organic molecules. However, this MSEP method is not applicable to screen large database because geometry optimization and frequency calculation require considerable computing time. To develop a fast but yet reliable approach, we have re-examined our previous work on organic molecules using two semi-empirical methods, AM1 and PM3. This new approach can be an efficient protocol in designing new molecules with improved properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1589-1592
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• 1994

We developed the ion plating system, consisted of the Facing Target Magnetron Sputtering System and the r.f, electrode of the coil type, which was available to control the reactive and the adhesion between thin film and substrate, and studied about the discharge characteristics and the optimum condition in order to form the high quality thin film. The characteristics of discharge and plasma was measured as Double Probe and Electrostatic Retarding Grid Analyzer. The incident ion energy on the substrate was increased as the increasing r.f power, bias voltage. By the r.f electrode, the ionization rate of the sputtered particles was about 75%, and the mean incident ion energy depend on the value which was difference between the plasma potential and biased substrate potential.