전해질로 나피온을 사용한 Ti/IrO_2 전극상에서 유기물의 양극산화 반응

강태구,윤영재,김희정,노성희,김선일 한국공업화학회 2003 응용화학 Vol.7 No.1

This paper describes the anodic oxidation od various alphathic alcohols in pure water using Nafion cation exchange membrane as solid polymer electrolyte. The oxidation has been carried out on an IrO_2 anode under conditions of simultaneous oxygen evolution. The experimental results for the anodic oxidation of four different alcohols are in good agreement with the theoretical model presented in a previous paper. Finally a simple experimental method is described for the determination of the relative reactivity of organics oxidation on IrO_2 anodes.

Sol-Gel방법에 의해서 성장시킨PbTiO₃박막의 결정화와 물리적 성질

구영진,강민진,정원태,김태현,김상수 昌原大學校 基礎科學硏究所 2000 基礎科學硏究所論文集 Vol.12 No.-

Ferroelectric PbTiO3 thin films coated on SiO2/Si(100) and ITO glass substrates were prepared by sol-gel processing of metal alkoxide solutions and solvents. The use of sol-gel method for preparing various functional films makes it possible for the homogeneous distribution of elements at the molecular level, precise composition control, lower temperature synthesis, large surface coating and high optical quality. First of all, the XRD investigation shows that perovskite phase of polycrystalline PbTiO3 was formed by four times coating of the concentrated solution and by the heat treatment over 500, 600℃(O2 gas and air) and over 10, 20, 30 min. Surfaces of thin films were crack-free and uniform and the average grain size investigated by SEM was 0.25∼1.00 ㎛. Dielectric constant of PbTiO3/ITO glass thin film were 380 ∼ 5.25 in the region of 1 kHz∼ 10 MHz at room temperature(30℃), respectively. From the hysteresis loop of PbTiO3/ITO glass thin film, a remnant polarization of 0.382 μC/cm2 and a coercive filed of 23.85 kV/cm were obtained. At the frequency(5 kHz), C-V measurements of films in MFIS and MFM configurations showed well-behaved C-V characteristics and an injection type hysteresis. The capacitance of flat band(CFB) was 60 pF. The band gap energies of the thin films depend on the assumption of direct or indirect transition. Using one layer structure model, we calculated refractive index, extinction coefficient, absorption coefficient and band gap energy of thin film in the wavelength range of 300 to 800 nm. The band gap energy, refractive index and extinction coefficient at λ = 6325 Å of the PbTiO3 thin film were 3.7 eV, 1.96 and 0.1 respectively.

메조포러스 물질에 담지된 팔라듐 촉매에서 메탄의 연소반응 : 티타니아 담지 효과 Effect of Titania Loading

강태구,김태진,김종호,서 곤 전남대학교 촉매연구소 1998 촉매학술발표회 Vol.- No.15

연소과정에 촉매를 사용하여 연소온도를 낮추고 완전산화시키면, 에너지를 효율적으로 이용할 수 있을 뿐 아니라 질소산화물 생성과 일산화탄소 등 불완전연소 물질을 줄일 수 있어 환경오염 방지 측면에서 매우 바람직하다. 화염이 없는 조건에서 안정적으로 열을 발생시키기 위한 중•저온 연소촉매로 활성이 높은 귀금속 성분을 지지체에 담지시켜 사용한다. 통과 유량이 크고 열 발생량이 많기 때문에, 연소촉매의 지지체는 물질과 열전달이 용이하도록 세공이 크고열적 안정성이 우수하여야 한다. 중간 크기의 세공이 발달되어 있는 메조포러스 물질은 물질전달과 열전달이 용이하다는 점에서 연소반응의 지지체로서 가능성이 높다.

Alachlor 農藥廢水의 오존酸化

李武康,黃泰九 경성대학교 1989 論文集 Vol.10 No.1

The batch and cotinuous study were performed to determine the optimum condition for the ozonization of alachlor. In the batch study, alachlor removal per unit ozone application rate was found to be 1.44 when the initial concentration of alachlor was 5 folds or greater than the ozone concentration. Alachlor removal was inhibited with the addition of NH??Cl and methanol. The removal, however, increased with pH and temperature. A continuous ozone oxidation study was also performed with alachlor wastewater. The COD removal efficiency was 21.4% at 10 minutes of reaction time, but alachlor removal was 3.8% only.

화농성 슬관절염이 동반된 수막구균성 수막염 1예

김태연,유진홍,박성환,김연식,임상현,신완식,강문원,정창훈,최문구,강지민 대한화학요법학회 1997 대한화학요법학회지 Vol.15 No.2

저자들은 최근 화농성 슬관절염과 병발한 수막구균성 수막염 1예를 체험하였고, 이는 국내에서 아직 보고되지 않은 드문 예로 사료되어 문헌고찰과 함께 보고하는 바이다. We recently experienced a case of meningococcal meningitis associated with pyogenic arthritis in a 37-year old male patient. Pyogenic arthritis developed in right knee joint during treatment for meningococcal meningitis. He was treated successfully by appropriate antibiotics and arthroscopic irrigation. To our knowledge, such a rare case has not ever been reported in Korea, Hence we report this case with a review of related literatures.

Cao-MgO-SiO₂-P₂O -CaF₂계 생체활성 결정화 유리의 기계적 성질에 미치는 ZrO₂및 Al₂O₃의 분산 강화 효과

박찬운,강건구,원대희,이민호,배태성 대한치과기재학회 1998 대한치과재료학회지 Vol.25 No.2

Bioactive glass-ceramics can form tight chemical bonds with bone, however, their poor mechanical properties may limit their clinical applications. Alumina ceramics show good biocompatibility and high strength but can't form chemical bonds with bone. Hydroxyapatite ceramics and bioglass form chemical bonds with bone but their strength and fracture are relatively low. Glass ceramics containing apatite and wollastonite crystals can form tight chemical bonds with bone and show relatively high strength and fracture toughness. Bioactive glass-ceramics toughened by alumina and tetragonal zirconia polycrystals show relatively high mechanical strength. Both bioactive and high strength ceramics will be widely applicable to many clinical applications. In this study, bioactive glass-ceramics toughened by alumina and zirconia polycrystals were fabricated, and crystallization behavior, biaxial flexure strength, fracture toughness, and bioactivity were measured. The results obtained were summarized as follows; 1. The major crystaline phase in the matrix glass were observed to be apatite, wollastonite, and β-TCP. 2. Biaxial flexure strength and fracture toughness values were more improved by the dispersion toughening of alumina and zirconia, and the improvement of mechanical strength was more higher in the dispersion toughening of zirconia than that of alumina. 3. The bioactivity, which was evaluted from apatite formation in the simulated body fluid, was higher in the dispersion toughening of Zr-O₂than that of Al₂O₃.

다환계 방향족 유기오염물을 함유한 폐수의 전기화학 처리

윤영재,강태구,김희정,노성희,김선일 한국공업화학회 2003 응용화학 Vol.7 No.1

This work has concerned the possibility to apply both direct and indirect electrolysis process for the treatment of waste containing poliaromatic compounds. Two different kinds of electrode materials have been used: DSA-type anodes to carry out direct electrolysis and carbon felt cathodes to ferform indirect electrolysis. On the contrary, in the case of the tested wastewater especially containing naphthalen- and anthraquinon sulphonic compounds they do not seem to be very suitable materials. Better results have been achieved using the carbon felt cathodes. In this case the COD of the tested wastewater can be remarkably decreased using H_2O_2 as oxidation agent.

A. 高校 科學 (生物·地球科學) 및 數學科 探究學習의 評價模型 定立과 評價紙 開發

李相協,權炳奎,林在圭,孫文求,吳岱燮,楊洪準,梁承榮,姜用熙,林成圭,金正遠,金吉民,兪正在 경북대학교 과학교육연구소 1982 科學敎育硏究誌 Vol.6 No.-

Currently the evaluation of high school science and mathematics learning has been too much knowledge-centered without concerning the inquiring ability or scientific attitude. This study, therefore, was made for the purpose of establishing of evaluation model for high school science (biology and earth science) and mathematics learning and its evaluation items. In this paper, the research was done about three fields, biology, earth science and mathematics. 1. For the biology, the evaluation methods of inquiry learning were studied with the foreign references, and proper evaluation items were suggested. 2. For the earth science, after analizing 5 kinds of earth science textbook of current using in high school, essential 19 items were selected. 5 of them were tested in test group and control group, then, the results were analized. 3. For the mathematice, the teaching elements of「Set」and「Flow chart」in mathematics (Ⅰ) were selected and structured. Detailed teaching objects were established and evaluation items were introduced.

장기적 트립토판 결여식이 생쥐의 유해감각예민도에 미치는 영향

서영대,박제민,김명정,전명호,양구범,장세헌,강철중,김정태,김용식 대한생물치료정신의학회 2000 생물치료정신의학 Vol.6 No.1

The depressive patients can be divided into two subgroups by presence and absence of pain symptoms. Those without pain symptoms have blunted pain sensitivity whereas those with pain have normal range of pain sensitivity, and are clinically characterized by anxiety and irritability. The aim of the study is to test if these clinical profiles of the depressives with pain symptoms are related with reduced level of brain serotonin(5-HT). Forty four mice were randomly divided into two groups : one group to be bred with tryptophan free diet and the other with normal control diet, each for 4 weeks. Before the beginning of the breeding period, measured were locomotor activity by open field test, anxiety by elevated plus maze and nociceptive sensitivity by tail flick test, before and after forced swimming(FS). During each FS, duration of immobilization was also measured. The sable sets of measurements were repeated at the end of the breeding period. The brain 5-HT and 5-hydroxyindoleacetic acid(5-HIAA) were measured by high performance liquid chromatography. The results were as follows 1.Four weeks of tryptophan free diet reduced significantly body weight, brain weight, and levels of 5-HT and 5-HIAA in the whole brain. 2.Tryptophan depletion did not influence basal nociceptive sensitivity as measured by tail flick latency before FS. The normal blunting of the pain sensitivity induced by forced swimming was preserved in the tryptophan depleted group. 3.Tryptophan depletion did not influence general locomotor activity in open field. 4.Tryptophan depletion increased significantly time spent on the open arms at the elevated plus maze test done before FS. This anxiolytic-like effect was reduced by FS. 5.Tryptophan depletion did not influence duration of immobilization during FS. From these results, it is suggested that the genesis of the depression with pain symptoms is not medicated by quantitative reduction of brain serotonin

Experimental investigation of optical thyristor operating as optical hard-limiter

Kang, Tae-Gu,Choi, Dong-Muk,Choi, Woon-Kyung,Choi, Young-Wan,Kim, Seong-Joo,Choi, Woo-Kyung Wiley Subscription Services, Inc., A Wiley Company 2007 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.49 No.11

<P>We demonstrate the optical thyristor operating as optical hard-limiter (OHL) in the optical channel and AND gate logic element (AGLE). The oxidized PnpN vertical-cavity laser (VCL)–depleted optical thyristor (DOT) clearly shows the nonlinear s-shaped current-voltage and lasing characteristics. A switching voltage of 5.24 V, a holding voltage of 1.50 V, and a threshold current of 0.65 mA is measured, making these devices attractive for optical processing applications. The VCL–DOT operating as OHL would enhance the system performance because it would exclude some combinations of interference patterns from causing errors as in all previous works. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2779–2780, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22850</P>