• 한국응용과학기술학회지
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• 제14권1호
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• pp.27-32
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• 1997

Furfurylidene acetophenone derivatives were synthesis, it was measured that nucleophilic addition made use of UV at a wide pH 1.0${\sim}$13.0 range in 30% dioxane-$H_2O$ solution, 25$^{\circ}C$. On the basis of general base catalysis, substitutent effect, confirmation of nucleophilic addition products, it was measured the reaction rate of furfurylidene acetophenone derivatives for the pH change. It may be concluded that a part was unrelated to pH and another part was in proportion to concentration of hydroxide ion: Above pH 10.0. sulfide anion adds to the double bond (Michael type addition), a part having no concern with pH, addition reaction to double bond is initiated by addition of neutral thiourea molecule. From the result of measurement the reaction rate, nucleophilic addition of furfurylidene acetophenone derivatives confirmed to the irreversible first order. Through measurement the substituent effect. It found that reaction rate was accelerated by electron attracting group. On the basis of these findings, nucleophilic addition of thiourea for the furfurylidene acetophenone derivative was proposed a fitting mechanisms.

• 한국재료학회지
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• 제15권6호
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• pp.393-398
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• 2005

The crystal structure and magnetic properties of the $Mg_{1-x}Zn_xFeAlO_4\;(0{\leq}x\leq1.0)$ have been investigated by means of x-ray diffractometry and $M\ddot{o}ssbauer$ spectroscopy. The samples$(0{\leq}x\leq1.0)$ have been prepared by the ceramic sintering method. The x-ray diffraction pattern shows that the crystal structure of the samples is a cubic spinel type. The lattice constant has been found by extrapolation using the Nelson-Riley function and it increases slightly from $8.3496\AA\;to\;8.4128\AA$ with Zn concentration. The $M\ddot{o}ssbauer$ spectra for x<0.4 show a superposition of two sextets ana a paramagnetic doublet at room temperature. The superparamagnetic doublet for x<0.4 seems to be due to Al ion in tetrahedral site by the superparamagnetic clustering effect.

• 한국재료학회지
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• 제11권10호
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• pp.859-862
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• 2001

The crystal structure and magnetic properties of the $Ni_{1-x} Cd_xFeAlO_4$(0$\leq$x$\leq$0.5) have been investigated by means of X-ray diffractometry and Mossbauer spectroscopy. The samples($0\leq$x$\leq$0.5) have been prepared by the ceramic sintering method. The X-ray diffraction pattern shows that the crystal structure of the samples is a cubic spinel type. The lattice constant has been found by extrapolation using the Nelson- Riley function and it increases slightly from $8.321{\AA}$ to $8.410{\AA}$ with Cd concentration. The Mossbauer spectra for x<0.4 show a superposition of two sextets and a paramagnetic doublet at room temperature. The cation distribution for x=0 was determined to be $[Fe_{0.75}Al_{0.25}]^A[NiFe_{0.25}Al_{0.75}^BO_4$. The superparamagnetic doublet for x< 0.4 seems to be due to A1 ion in tetrahedral site by the superparamagnetic clustering effect.

• Journal of Magnetics
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• 제11권1호
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• pp.12-15
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• 2006

Magnetic and electronic properties of reduced rutile titanium dioxide $(TiO_{2-\delta})$ thin films doped by Mn have been investigated. The present sol-gel-grown semiconducting $TiO_{2-\delta}:Mn$ films exhibit a ferromagnetic behavior at room temperature for a limited range of Mn content. The Mn-doped films have p-type electrical conductivity with the carrier concentration near $10^{19}\;cm^{-3}$. The observed room-temperature ferromagnetism is believed to be intrinsic but not related to free carriers such as holes. Oxygen vacancies are likely to contribute to the room-temperature ferromagnetism-trapped carriers in oxygen vacancies can mediate a ferromagnetic coupling between neighboring $Mn^{+3}$ ions. The energy band-gap change due to the Mn doping measured by spectroscopic ellipsometry exhibits a red-shift compared to that of the undoped sample at low Mn content. It is explainable in terms of strong spin-exchange interactions between Mn ion and the carrier.

• 수산해양기술연구
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• 제20권2호
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• pp.133-136
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• 1984

정변위 인장시험기를 사용하여 SUS 304강 용접열 영향부의 여러 가지 염화 마그네슘용액 중에서의 SCC 발생 특성을 연구한 결과 다음과 같은 결론을 얻었다. 1) SCC 발생 잠복기간은 초기 응력강도계수 K 하(Ii) 값은 낮게 함으로써 크게 지연된다. 2) 비등 염화 마그네슘 용액 중에서의 SCC 발생은 부하와 Cl 이온의 농도에 의한 부동태 피막의 파손에 기인된다. 3) SUS 304 강 용접열 영향부의 SCC 발생 감수성은 높은 농도의 염화 마그네슘 용액일수록 온도를 낮게 함으로써 둔화된다.

• 분석과학
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• 제6권1호
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• pp.131-139
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• 1993

아연광 중 미량으로 존재하는 갈륨 및 인듐을 유도결합 플라스마 원자방출분광법(ICP-AES)으로 분석할 때 간섭하는 아연 및 다른 이온들과 특히 Fe(III) 이온으로부터 이들을 분리하는 방법에 대해 연구하였다. 갈륨과 인듐을 tributyl phosphate(TBP)로 용매추출하였는데 이때 영향을 주는 산농도, 다른 이온들의 간섭, 수용액상/유기상의 비율, TBP의 농도 및 탈거율 등에 대하여 조사하였다. 갈륨과 인듐이 함유되어 있는 아연광을 녹인 5N 염산용액에서 100% TBP로 추출하여 아연 및 기타 간섭이온들로부터 분리하였으며, 이때 철(III)이온은 hydroxylamine hydrochloride를 사용하여 Fe(II)로 환원시켜 coetraction되는 것을 방지하였다. 유기상으로부터 갈륨과 인듐의 탈거는 0.02N 염산용액으로 역추출하여 이루어졌으며 이 용액을 ICP-AES로 측정하여 이들을 정량하였다. 전체적으로 추출률이 95% 이상으로 정량적이었다.

• 한국물환경학회지
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• 제28권1호
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• pp.115-120
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• 2012

Different colloidal particles generally co-exist in the water and wastewater. Thus, there needs to identify practical electrokinetic characteristics of the particles, comparing with the case when each colloidal material is independently distributed. In this study, changes of overall zeta potential was examined through mixed dispersions of $TiO_{2}$ and $MnO_{2}$. The mixing ratios were classified into 3-type in order to distinguish the effects of the proportions of each particle from those of total concentration in colloidal suspensions. The types are single colloidal dispersions of $TiO_{2}$ and $MnO_{2}$ (1:0, 0:1), mixed dispersions at different ratios (0.75:0.25, 0.5:0.5, 0.25:0.75), and a mixed dispersion with doubled concentration (1:1), respectively. It showed that the overall variation of zeta potential as a function of pH was intensified in a colloidal dispersion with the ratio of 1:1. It was concerned that the double action of ion would contribute to this result. On the one hand, the zeta potentials of each colloidal dispersion commonly decreased at the state of strong acid and base under the influence of compression of the electric double layer. The changing patterns were also considered through calculating total interaction energy between colloidal particles based on DLVO theory and measuring turbidity of the colloidal dispersions.

• 조명전기설비학회논문지
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• 제17권6호
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• pp.77-82
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• 2003

본 논문에서는 강한 불평등전계를 형성시킬 수 있는 다선형전극을 강전해수 발생장치내에 설치하여 전계집중효과에 의해 발생되는 기포내의 선행방전의 형태와 기포방전이 수소이온농도와 산화환원전위반응에 미치는 영향을 검토하고자 하였다. 실험결과, 강전해수 발생장치내의 양전극측을 다선형으로 함으로써 양전극측에서 발생되는 기포내에서 비유전율 차이에 의한 기포내의 선행방전을 관찰할 수 있었다. 그리고 기포방전에 의해 발생된 이온들이 강전해수 발생장치내에 용해됨으로써 전해수의 이온농도를 증가시켰다. 이때 발생된 고농도의 이온들을 분리집속 시키고 산화환원작용을 크게 증가시켜 고농도의 강전해수를 발생시킬 수 있었다.

• 조명전기설비학회논문지
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• 제27권6호
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• pp.95-99
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• 2013

Furnace is currently the most important doping process using POCl3 in solar cell. However furnace need an expensive equipment cost and it has to purge a poisonous gas. Moreover, furnace typically difficult appling for selective emitters. In this study, we developed a new atmospheric pressure plasma source, in this procedure, we research the atmospheric pressure plasma doping that dopant is phosphoric acid($H_3PO_4$). Metal tube injected Ar gas was inputted 5 kV of a low frequency(scores of kHz) induced inverter, so plasma discharged at metal tube. We used the P type silicon wafer of solar cell. We regulated phosphoric acid($H_3PO_4$) concentration on 10% and plasma treatment time is 90 s, 150 s, we experiment that plasma current is 70 mA. We check the doping depth that 287 nm at 90 s and 621 nm at 150 s. We analysis and measurement the doping profile by using SIMS(Secondary Ion Mass Spectroscopy). We calculate and grasp the sheet resistance using conventional sheet resistance formula, so there are 240 Ohm/sq at 90 s and 212 Ohm/sq at 150 s. We analysis oxygen and nitrogen profile of concentration compared with furnace to check the doped defect of atmosphere.

• The Korean Journal of Physiology and Pharmacology
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• 제12권2호
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• pp.73-77
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• 2008

Recent studies have documented that testosterone relaxes several smooth muscles by modulating $K^+$ channel activities. Smooth muscles of seminal vesicles playa fundamental role in ejaculation, which might involve testosterone. This study was aimed to assess the role of testosterone in seminal vesicular motility by studying its effects on contractile agents and on the ion channels of single vesicular myocytes in a rabbit model. The contractile responses of circular smooth muscle strips of rabbit seminal vesicles to norepinephrine ($10{\mu}M$), a high concentration of KCI (70 mM), and testosterone ($10{\mu}M$) were observed. Single vesicular myocytes of rabbit were isolated using proteolytic enzymes including collagenase and papain. Inside-out, attached, and whole-cell configurations were examined using the patch clamp technique. The applications of $10{\mu}M$ norepinephrine or 70 mM KCl induced tonic contractions, and $10{\mu}M$ testosterone (pharmacological concentration) evoked dose-dependent relaxations of these precontracted strips. Various $K^+$ channel blockers, such as tetraethylammonium (TEA; $10{\mu}M$), iberiotoxin ($0.1{\mu}M$), 4-aminopyridine (4-AP, $10{\mu}M$), or glibenclamide ($10{\mu}M$) rarely affected these relaxations. Single channel data (of inside-out and attached configurations) of BK channel activity were also hardly affected by testosterone ($10{\mu}M$). On the other hand, however, testosterone reduced L-type $Ca^{2+}$ currents significantly, and found to induce acute relaxation of seminal vesicular smooth muscle and this was mediated, at least in part, by $Ca^{2+}$ current inhibition in rabbit.