• 센서학회지
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• 제23권3호
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• pp.170-172
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• 2014

$CO_2$ sensor was used only one solid electrolyte in many cases. To improve the sensing characteristics of $CO_2$ sensors, solid electrolyte $CO_2$ sensor has been developed by bi-electrolyte type sensor using Na-Beta-alumina and YSZ. However, in many further studies, bi-electrolyte type sensor was made by pellet pressed by press machine and additional treatment for formation of interface. In the aspect of mass production, using thick film and additional treatment is not suitable. In this study, $CO_2$ sensor was fabricated by bi-electrolyte structure which was made by an NBA paste layer deposited on YSZ pellet and fired at $1650^{\circ}C$ for 2 hour. The formation of stable interface between YSZ and NBA were confirmed by SEM image. When the type IV electrochemical cell arrangement represented by $CO_2,O_2,Pt{\mid}Li_2CO_3-CaCO_3{\parallel}NBA{\parallel}YSZ{\mid}O_2,Pt$ is used to measure the $CO_2$ concentration in air. This sensor EMF should depend only on the concentration of $CO_2$ by logarithmic. Also, sensor shows $P_{CO_2}$ and EMF relationship like nerstian reaction at a temperature of $450^{\circ}C$.

• Journal of Photoscience
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• 제1권1호
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• pp.31-37
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• 1994

Photoirradiation at > 300 nm onto a suspension of platinized TiO$_2$ (TiO$_2$-Pt) particles in an aqueous solution. of N$_{\varepsilon}$-carbamyI-L-lysine (Lys(CONH)$_2$) induced the selective N-cyclization of Lys(CONH$_2$) into almost optically pure L-pipecolinic acid (PCA) under argon atmosphere at ambient temperature. Among various TiO$_2$-Pt catalysts, a P-25 (Degussa) powder platinized via impregnation from chloroplatinic acid followed by hydrogen reduction at 753 K exhibited the highest photocatalytic activity for Lys(CONH$_2$) consumption and L-PCA production. GC-MS analyses of L-PCA obtained photocatalytically from $^{15}$N$\alpha$-Lys(CONH$_2$) revealed the selective formation $^{15}$N-substituted L-PCA. This implies that the mechanism for L-PCA production contains selective cleavage of C$_{\varepsilon}$-N bond and intramolecular alkylation at $\alpha$-amino group. Effect of pH on the rate of this photocatalytic reaction was investigated in detail and compared with the pH-dependent charge distribution in Lys(CONH$_2$) molecule. It is clarified that protonation-deprotonation of $\alpha$-amino group gives marked influence on the rate and selectivity of the photocatalytic reaction. On the basis of these results, it is concluded that the selective production of optically pure L-PCA, especially in an acidic suspension of TiO$_2$-Pt, was attributed to the enhanced protonation of $\alpha$-amino group to prevent undesirable oxidation by photogenerated positive holes and blocking of $\varepsilon$-amino group to yield racemic Schiff base intermediate.

• 분석과학
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• 제8권4호
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• pp.561-568
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• 1995

Two methods, precipitation and ultrafiltration, were applied in order to recover platinum group metals(PGM) by complexing them with water-soluble polyelectrolytes, e.g., polyethyleneimine [PEl], poly(2-vinylpyridine) [2-PVP], poly (4-vinylpyridine) [4-PVP], and poly (styrene sulfonic acid) [PSSA]. In the precipitation method, the PGM-polyelectrolyte complex that was formed by mixing first with polybase, e.g.,4-PVP at pH 1 was precipitated by further mixing with polyacid, e.g., PSSA. However, the recovery of PGM obtained by this method was not quantitative(less than 70%). The "sandwiching" binding between the metal anions and two polyelectrolytes was examined by X-ray photoelectron spectroscopy(XPS). The XPS studies indicated that the PGM atom was bound with the acdic and basic polyelectrolyte via its oxygen and nitrogen atom, respectively. The recovery of PGM using polyelectrolyte was further studied by ultrafiltration methods as follows : The PGM ions, eomplexed at pH 1 with polyelectrolyte, allowed the applicntion of membrane filtration by virtue of the great differences in molecular weights between PGM and other low molecular weight species. By applying this method, Pd and Pt (ca. $10^{-4}M$) were selectively separated almost quantitatively from coexisting metal ions, e.g., $Cu^{2+}$ and $Ni^{2+}$. The EPR spectra and viscosity measurements indicated that these polyelectrlytes were not bound to $Cu^{2+}$ and $Ni^{2+}$ ions at this pH, which provided the basis for selective separation of PGM(Pd, Pt and Rh) from these coexisting ions.

• 분석과학
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• 제8권4호
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• pp.691-698
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• 1995

The complexation of platinum and palladium with synthetic polyelectrolytes was studied. The successive and overall stability constants of Pd(II) with PEI and 2PVP were obtained by potentiometric titration. Because of the slow equilibrium time, the potentiometric titrations were performed using the home-made automatic titrator in order to analyze the complexations according to the modified Bjerrum method. The complex formation constant of Pt(IV) with 2PVP, measured by differential pulse polarography, was calculated from the peak currents that were obtained in non-complexing media and in solution containing 2PVP.

• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1099-1105
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• 1998

A series of (diamine)isopropylidenmalonatoplatinum(Ⅱ) complexes and the oxidation products, (diamine)Pt (OOC)2C=C(CH3)2(X)2, (diamine=ethylenediamine(en), 1,2-diaminopropan(dap), N-methylethylenediamine(men); X=OH, OCOCH3, OCOCF3), have been prepared, and their interaction with guanosine-5'-monophosphate (5'-GMP) have been examined by means of 1H NMR spectroscopy. The present platinum(Ⅱ) complexes have shown to interact with 5'-GMP through N7 coordination in two concecutive steps in a similar way as with cisplatin, but no interaction between the present platinum(Ⅳ) complexes and 5'-GMP was observed. However, in the presence of ascorbic acid, the platinum(Ⅳ) complexes have been found to interact with 5'-GMP with the reaction rate depending on their reduction rate.

• Bulletin of the Korean Chemical Society
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• 제22권11호
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• pp.1183-1191
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• 2001

The metallorganic chemical vapor deposition (MOCVD) method has been used to prepare TiO2 thin films for the degradation of hazardous organic compounds, such as 2-chlorophenol (2-CP). The effect of supporting materials and metal doping on the photocatalytic activity of TiO2 thin films also has been studied. TiO2 thin films were coated onto various supporting materials, including stainless steel cloth(SS), quartz glass tube (QGT), and silica gel (SG). Transition metals, such as Pd(II), Pt(IV), Nd(III) and Fe(III), were doped onto TiO2 thin film. The results indicate that Nd(Ⅲ) doping improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 ${\mu}m)$ appears to be the best support. An optimal amount of doping material at 1.0 percent (w/w) of TiO2-substrate thin film gives the best photodegration of 2-CP.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.145-145
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• 2000

M-CeO2 (M : noble metal) catalysts have been widely studied as three-way catalysts and methanol synthesis catalysts. Ceria is thought to play a number of roles in these catalysts. The Ce(IV)/Ce(III) redox pair may store/release gases under oxidizing/reducing conditions, extending the operational window. Additionally, metal-ceria interactions lead to several effects, including the dispersion of the active components and promoting the activation of molecules such as CO or NO. Pd is a promising component to current TWC formulations and behaves particularly well when compared with Pt and Rh-based catalysts for low-temperature oxidation of Co and hydrocarbon. However the effect of Pd-ceria interactions on the physicochemical properties of Pd and the redox properties of Ce is not elucidated yet. In order to know exactly about the metal-ceria interactions, the model study are expecting to give a better environment, resulting in the wide use of the surface science tools. The substrate was Si(100) wafer, on which Ta metal was sputtered as a thickness of 100nm. The CeO2 thin film of 30nm was deposited by using the magnetron sputtering. Spin coating and magnetron sputtering methods were used to make the Pd thin film layer. The prepared sample was investigated by in-situ XPS, AES, SEM and AFM analysis.

• 정신신체의학
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• 제6권2호
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• pp.147-154
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• 1998

본 연구에서는 공황장애 환자에 대한 인지행동치료의 효과에 영향을 미치는 환자 특성을 확인하기 위하여 다면적 인성검사를 사용하여 환자의 특성을 측정하고 이들 환자 특성 중 어떤 변인이 치료결과를 예측하는데 도움이 되는지를 알아보았다. 31명의 공황장애 환자를 대상으로 11주의 공황장애 인지행동치료 프로그램을 실시하였고, 치료전에 다면적 인성검사를 실시하였으며, 치료 전 후에 Beck Depression Inventory(BDI), Spielberger State-Trait Anxiety Inventory의 상태 불안 질문지(STAI-State), Agoraphobic Cognition Questionniaire(ACQ), Body Sensation Questionnaire(BSQ)의 질문지와 환자의 자기보고 등 5가지를 실시하여 치료 성과의 지표로 사용하였다. 최종상태 기능 (End-State Functioning) 에 따라 치료 결과가 좋은 집단(상위 최종상태 집단)과 치료 결과가 나쁜 집단(하위 최종상태 집단)을 구분하여 두 집단의 특성용 비교 분석하여 다음과 같은 결과를 얻었다. 1) 다면적 인성검사의 건강염려증 척도(Hs), 우울증 척도(D), 히스테리 척도(Hy), 강박증 척도(Pt), 정신분열증 척도(Sc), 그리고 타당도 척도인 F 척도에서 하위 최종상태 집단이 상위 최종상태 집단에 비해 유의미하게 높은 점수를 보였다. 하지만 이러한 차이는 치료 효과에 영향을 미치는 환자 변인이라고 하기보다는 단순히 환자가 가진 증상의 심한 정도를 반영하는 것으로 보인다. 2) 치료 전에 실시한 다섯 가지 평가 지표에서 기본적으로 하위 최종상태 집단이 상위 최종상태 집단보다 증상의 정도가 심했지만, 두 집단 모두 치료를 통하여 비슷한 수준의 치료적 변화를 보인 결과는 1)의 해석을 지지해준다. 이상의 결과를 종합할 때, 다면적 인성검사는 인지행동 치료 결과에 영향을 미치는 환자의 특성을 파악하는데는 효과적이지 못한 방법으로 생각되며, 추후 연구에서는 보다 직접적으로 성격 특성을 측정할 수 있는 방법을 사용하여 환자 변인을 찾아 볼 필요가 있을 것으로 생각된다.

• Journal of Chest Surgery
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• 제29권9호
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• pp.964-970
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• 1996

1986년 2월부터 1996년 1월까지 108명의 환자에게 SJM 판막을 이용한 판막치환수술을 시행하고 1996년 2월까지 10년 동안 임상적으로 추적, 분석하였다. 성별은 남자 55명, 여자 53명이 였고 연령분포는 최소 11세에서 최고 60세로 평균 36.3 $\pm$ 10.4세였다. 치환된 판막은 승모판에 88개 대동맥 판에 54개 삼첨판에 1개였는데 승모판막치환에는 31mm(32), 33mm (23), 29inm(20), 27mm(10), 25mm(2), 그리고 35rnrn(1) 등이 사용되었고 대동맥 판치환에는 23rnm(21), 21min(18), 19mm(7), 25mm(5), 27mm(2), 그리고 33inm(1) 등이 사용되 었으며 삼첨판에 31mm(1)가 사용되었다. 술전 NYHA 기능적 분류는 II(14례), III(73례), IV(21례)였으나 술후에는 I(89례), II(16례)로 대부분 호전되었다. 술후 조기합병증은 15례(13.9%)에서 발생하였는데 저심박출증이 5례(4.6%)로 가장 많았고 3례(2.8%)의 술후 조기사망이 있었다. 술후 조기사망자를 포함한 전체 추적기간은 108례에서 평균 4.1$\pm$2.9년(437.6환자-년)이 었으며 후기 합병증은 5례(1.14%/환자-년)에서 발생하였는데 혈전색증(2례), 판막주위누출(1례), 혈전색과 판막주위누출(1례)및 판막염증(1례)등이었으 \ulcorner판막실패 례는 없었다. 재수술은 2례에서 시행되었고 2례가 사망하여 10년간 생존율은 93.6$\pm$3.1%였고 10년간 합병증이 없을 확율은 91.4$\pm$3.4%였다.

• Journal of Chest Surgery
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• 제12권4호
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• pp.350-354
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• 1979

The incidence of congenital aortic valvular stenosis has been known rare, and approximately 3-6% of congenital heart diseases. Recently, we experienced 1 case of congenital aortic valvular stenosis, and which was corrected surgically under extracorporeal circulation successfully. A 11 years old male pt. was admitted to N.M.C. because of dyspnea, dizziness, chest pain and episode of syncope. An auscultation, harsh systolic murmur [Gr. IV/VI] was noted at aortic area and also palpable strong thrill. ECG showed LVH c strain pattern and suspicious LVH finding in simple chest P-A film. In Lt. cardiac catheterization, abrupt pressure change [110mmHg] between LV & Aorta was noted across the aortic valve. And aortic insufficiency was absent, well visualized both coronary arteries and suspicious bicuspid aortic valve in aortography. Valve form was bicuspid, large one was noncoronary cusp and another cusp was Rt. & Lt. coronary cusp which was interpositioned rudimentary commissure. Central aortic orifice was about 5ram in diameter. Valvulotomy was done along the fusioned commissure between noncoronary cusp and Rt. & Lt.coronary cusp, and then short incision was added between Rt. coronary cusp & Lt. coronary cusp. Immediate postoperative course smooth but unknown cardiac arrest was noted in POD second day. Complete recovery was done without sequelae by resuscitation. After operation, clinical symptoms were subsided but systolic murmur [Gr. II/VI] was audible at aortic area, diastolic murmur was absent. ECG showed still remained LVH but much decreased R wave voltage in Lt. precordial leads. Simple chest P-A showed no interval changes compared to preop film. Control Lt. heart catheterization revealed still remained pressure gradient [40ramrig] between LV & Aorta. But much decreased pressure gradient compared to preop pressure gradient [110mmHg].