TiN 超硬薄膜의 被覆에 關한 硏究

金鳳杰,金昌煜,金宗範 慶熙大學校 材料科學技術硏究所 1989 材料科學技術硏究論集 Vol.2 No.-

The TiN film was coated by normal pressure chemical vapor deposition method on the Al_(2)O_(3) plate using TiCl_(4). N_(2) and H_(2) obtained from NH_(3) gas. The effect of the deposition time, temperature, N_(2)/H_(2) ratio, TiCl_(4) (g) flew rate and total flow rate of reactant gas on deposition were investigated. The results were as follows. 1. The thickness of TiN thin film was increased linealy with increase of deposition time and TiCl_(4)(g) flow rate. 2. The microhardness of TiN thin film was high (1,950 ㎏_(f)/㎟) when the crystal plane was oriented preferably along (220) plane, and such orientation was prevalent in N_(2)/H_(2) ratio 0.352 and TiCl_(4)(g) flow rate more than 28㎖/min respectively. 3. The rate determining step of the deposition rate was mass transport of reactant gas and apparent activation energy was 9.3㎉/㏖.

濕式法에 依한 γ-MnO_2 製造에 關한 硏究(第2報) : Purification of Manganes Oxides by Acid Treatment

金鳳杰,姜泰範,韓正洙 慶熙大學校 1982 論文集 Vol.11 No.-

Studies on the effect of reaction temperature, reaction time and concentration of acid on the purification of manganese oxides was conducted to manufacture γ-MnO₂ available as dry cell depolarizer by wet process. The results obtained were follows: 1.When oxidized the precipitates of OH￣/Mn^++ mole ratio 2.2 by aeration at 13℃ for 6 hours, MnO₂content obtained 89.99%, which was identified as crystalline γ-MnO₂by X-ray diffraction analysis. 2. When manganese oxides was treated at 70℃ for 2hrs with 30% H₂SO₄and 30% HNO₃, the highest content, of MnO₂was obtained as 96.90% and 96.60%, respectively, which was identified as crystalline γ-MnO₂by X-ray diffraction analysis and different thermal analysis.

酸化리튬의 置換에 따른 硼硅酸유리의 分相에 關한 硏究

金鳳杰,梁重植 慶熙大學校 1980 論文集 Vol.10 No.-

The phase separation of low-alkali borosilicate glass with the composition of 6.25 Na_2O·18.75 B_2O_3· 75.00 SiO_2 (mole%) substituting Li_2O for Na_2O was studied. The phase separation in the temperature range of transformation was examined with various heating temperatures and soaking times. Durability to water, thermal expansion, specifie density and visible light transmittance of the specimen were investigated and the microstructure of the separated phase was also observed by transmission electron micrograph techniques. The maximum alkali extraction result with he best phase separation effect was obtained when Na_2O of the base glass was replaced with 1.88 Li_2O (mole %) and electron micrograph of carbon film replica of 1.88 Li_2O·4.37 Na_2O·18.75 B_2O_3·75.00 SiO_2 (mole %) glass showed that glass consisted of homogeneous two phases. The minimum specific density was shown with the specimen treated at 570℃ and it was also shown that the longer the treating time the lower the specific density. The apparent activation energies of approximately 45 Kcal/mole by the alkali extraction and 43Kcal/mole by the thermal expansion method were derived from the Arrhenius plots, respectively.

중성자 조사에 의해 생성된 실리콘 결정내의 점결함 연구

이운섭,류근걸,김봉구 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

반도체 소자의 기판 재료로 사용되고 있는 실리콘 웨이퍼는 그 정밀도가 매우 중요하다.본 연구에서는 균일한 Dopant 농도 분포를 얻을 수 있는 중성자 변환 Doping을 이용하여 실리콘에 인(P)을 Doping하는 연구를 수행하였다.중성자 변환 Doping, 즉 NTD(Neutron Transmutation Doping)란 원자번호 30인 실리콘 동위원소에 중성자가 조사되면 원자번호 31인 실리콘으로 변환되고, 2.6시간의 반감기를 갖고 decay 되면서 인(P)으로 변하게 되어 실리콘 웨이퍼에 n-type 전도를 갖게 하는 것을 말한다.본 연구에서는 하나로 원자로를 이용하여 고저항(1000-2000Ω㎝) FZ 실리콘 웨이퍼에 중성자 조사하여 저항의 변화를 관찰하였고, 중성자 조사시 발생하는 점결함을 분석하여 점결함이 저항 변화에 미치는 영향을 알아보았다.중성자 조사 전 이론적 계산에 의해 16.8Ω㎝와 4.76Ω㎝의 저항을 얻을 수 있을 것으로 예상되었고, 중성자 조사 후 SRP로 측정한 결과 실리콘 웨이퍼가 3Ω㎝와 2.5Ω㎝의 저항을 가지고 있을 확인할 수 있었으며, FT-IR 분석결과 점결함의 변화 양상을 확인할 수 있었다.

Validation of Korean Stroop Test in the Screening of Minimal Hepatic Encephalopathy

( Eileen L. Yoon ),( Dae Won Jun ),( Jae Yoon Jeong ),( Tae Yeob Kim ),( Do Seon Song ),( Sang Bong Ahn ),( Hee Yeon Kim ),( Young Kul Jung ),( Myeong Jun Song ),( Sung Eun Kim ),( Hyoung Su Kim ),( S 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Minimal hepatic encephalopathy (mHE) has poor prognosis but hardly drawn attention when patients have no symptoms. We aimed to validate Korean stroop test in the screening of mHE. Methods: Chronic hepatitis B related liver cirrhosis (LC) patients without history of overt hepatic encephalopathy were recruited prospectively from 13 centers for two years. All participants completed Portosystemic encephalopathy syndrome test (PHES) and Korean stroop test. Korean stroop test is consisted of 2 On-states (color, word) and 2 Off-states (inhibition, switching). Correct response rates and response times were measured. Four types of “OnTime+OffTime” have been analyzed (color+inhibition, color+switching, word+inhibition, and word+switching). mHE was diagnosed when PHES scores less than -4. Healthy controls (HC) were also recruited (n=376). Results: Among 223 LC patients, 67.3% was male. Mean age was 53 years. Prevalence of mHE was 20.6%. Response times for each states showed negative correlation with PHES scores (P<0.001). Also color+inhibition, color+switching, word+inhibition, and word+switching showed negative correlation with PHES scores, -0.361, -0.310, -0.442, and -0.336, respectively(all P<0.001). The highest AUC in the discrimination of mHE among various “OnTime+OffTime” was word+inhibition (AUC 0.75, 95% C.I 0.67-0.84, P<0.001). Mean values of word+inhibition were significantly different among the three groups, which were 54.6±13.2sec, 63.4±18.2sec, and 83.4±27.8sec in HC, LC without mHE, and LC with mHE, respectively (all P<0.001). Among various factors, time for word+inhibition was the only significant factor (OR 1.04, 95% C.I 1.02-1.06, P<0.001) in multivariate analysis for diagnosis of mHE. Conclusions: Korean stroop test is simple and valid method for screening of mHE.

Validation of Usefulness for Korean Paper and Pencil Test to Detect Minimal Hepatic Encephalopathy in Korea

( Jae Yoon Jeong ),( Dae Won Jun ),( Eileen L. Yoon ),( Tae Yeob Kim ),( Do Seon Song ),( Sang Bong Ahn ),( Hee Yeon Kim ),( Young Kul Jung ),( Myeong Jun Song ),( Sung Eun Kim ),( Hyoung Su Kim ),( S 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: We recently developed a new Korean paper and pencil test (KPPT) as a ‘copyleft’ test. The aim of this study is to validate the usefulness for a KPPT to detect minimal hepatic encephalopathy (MHE) in Korea. Methods: Two hundred twenty five patients with hepatitis B virus related cirrhosis without overt HE were prospectively enrolled in 13 centers for two years. All patients underwent psychometric hepatic encephalopathy score (PHES, gold standard), KPPT and Korean stroop test. MHE was defined as ≤ -5 points in PHES. And MHE in KPPT defined an impaired performance under - 1.5 standard deviations from the mean on more than 2 tests in short version (number connection test-A, number connection test-B, digit span test-forward, digit span test-backward and symbol digit modality test) and long version (short version + word list memory test and MCG complex figures test). Results: The mean age of the patients was 53.4 years with males predominant (67.1%). Prevalence of MHE was 20.9% in using PHES, 25.3% in using KPPT short version, and 41.3% in using KPPT long version. There was significant difference between patients with MHE and those without MHE in all tests that constitute KPPT (P<0.05). Also, all tests that constitute KPPT except copy value of MCG Complex Figures test showed a statistically significant difference between patients with MHE and those without MHE, according to OnTime+OffTime (word+inhibition) of Korean stroop test. In the diagnosis of MHE, the concordance between PHES and KPPT short version was 85.8% (sensitivity 76.6%, specificity 88.2%), and the concordance between PHES and KPPT long version was 73.3% (sensitivity 85.1%, specificity 70.2%). The area under the curve of total score of KPPT short version and long version were 0.809 (95% C.I 0.737-0.880, P<0.001) and 0.820 (95% C.I 0.755-0.884, P<0.001) in the diagnosis of MHE. Conclusions: KPPT have good correlation with conventional PHES to detect MHE in patients with cirrhosis. Also, the diagnostic performance of the KPPT short version is comparable to the diagnostic performance of the long version.

Association between Sarcopenia and Minimal Hepatic Encephalopathy and Quality of Life in Patients with Liver Cirrhosis

( Do Seon Song ),( Dae Won Jun ),( Jae Yoon Jeong ),( Tae Yeob Kim ),( Sang Bong Ahn ),( Hee Yeon Kim ),( Young Kul Jung ),( Myeong Jun Song ),( Sung Eun Kim ),( Hyoung Su Kim ),( Soung Won Jeong ),( 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: We aimed to investigate the association between sarcopenia and minimal hepatic encephalopathy and quality of life in cirrhotic patients. Methods: Liver cirrhosis patients associated with chronic hepatitis B were prospectively recruited in 15 hospitals between April 2016 and December 2017. Among these 223 patients, 128 patients who assessed handgrip strength and skeletal muscle mass were analyzed. Minimal hepatic encephalopathy was diagnosed when psychometric hepatic encephalopathy score (PHES) was less than -4. Quality of life was assessed by 36-Item Short Form Health Survey (SF-36). Sarcopenia was defined as lower quintile using handgrip strength and skeletal muscle index (SMI). SMI was calculated by total muscle mass/height². Results: Mean age was 53.5 years, and 63.3% was male. MHE was 27.3%. Cut-off values of sarcopenia were as follows; 10.2 kg/m2 in men and 8.15kg/m2 in women for sarcopenia by SMI, and 27 kg in men and 18 kg in women for sarcopenia by handgrip strength. There were no significant differences in the prevalence of MHE and PHES score value between sarcopenic and non-sarcopenic group (P=0.077 and P=0.152 by SMI, P=0.935 and P=0.888 by handgrip strength). An SF-36 score of the sarcopenic group was significantly lower than that of the non-sarcopenic group (60.2±17.9 vs. 68.1±17.1, P=0.038) by SMI, but not by handgrip strength (62.6±16.8 vs. 67.3±17.7, P=0.260). Among 8 domains constituting SF-36 score, general health score was significantly lower in the sarcopenic group by SMI (P=0.032). Pain score and energy/fatigue scores were significantly lower in the sarcopenic group by handgrip strength (P=0.035 and P=0.020). Conclusions: Sarcopenia by SMI and handgrip strength was not associated with MHE. However, sarcopenia by SMI and handgrip strength were significantly associated with quality of life.

濕式法에 依한 γ-MnO_2 製造에 關한 硏究

金鳳杰,姜泰範 慶熙大學校 1979 論文集 Vol.9 No.-

In order to make γ-MnO_2 substance for a dry cell which is considered as higher oxidation grade through the chemical process, 0.lM-MnSO_4 solution is added by the NaOH solution of varied concentration. Three difference substance which are of consequently obtained from the above experiment, are oxidized with air. An analysis has been made for the product which is preparated to the mole ratio from the above method through the measurement with X-Ray differactometer. The consequences of the applied experiment in this research are as follows: 1. Mn_3O_4-MnSO_4-nH_2O was obtained when oxidized by air the suspension solution of 2MnSO_4-Mn(OH)_2, for two hours, which formed at mole ratio 1 of OH^-/Mn^(++). 2. γ-MnOOH·MnSO_4 -nH_2O was obtained by airation the suspension solution of 2MnSO_4-Mn(OH)_2, for 24 hours, which formed at mole ratio 1. 3. γ-MnO_2 was obtained by airation the suspension solution of Mn(OH)_2, for 24 hours, which was formed at mole ratio 3. 4. γ-Mn_2O_3 was obtained by airation the suspension solution of NaHMnO_2, for 24 hours, which was formed at mole ratio 5.

Ceramic Capacitor 제조용 재료의 개발에 關한 硏究

金鳳杰,金昌煜 慶熙大學校 1979 論文集 Vol.9 No.-

This essay is concerened upon BaTiO_3-SnO_2 ceramic capacitors which were made from pure barium titanate. In datails, The contents are as follows. 1. Pure barium titanate is made of decomposition of barium titanyl oxalate. 2. BaTiO_3-SnO_2 Ceramic capacitors, 15% tin oxide addition to pure barium titanate, have good dielectric effects to variable temperature. 3. In comparation to the dielectric effect variable temperature BaTiO_3-SnO_2 Ceramic capacitor was better than national products.

Isopolytungstate 음이온의 성장과정에 관한 연구

김봉걸 한국화학공학회 1972 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.10 No.4

Much works have been done on isopolytungstate ion formation processes by acidifying sodium tungstate solutions. Concerning this field of research which are closely related to improving quality of the refined final tungsten products in the metallic form, there have been reports by investigators such as Kepert, Jander, Souchay, Aveston, and others. However these studies were done by potentiometric, conductometric, polarographic and ultracentrifugal methods, and the results were found to be mutually inconsistent. The cryoscopic method, however, has not been fully investigated in spite of the accuracy of this method at neutral range in contrast to the potentiometric method which have often been tried for the study of isopolytungstates. Therefore, cryoscopic method was adopted in this work, and the following results were obtained for the condensation of isopolytungstates in various pH ranges, by mean of the pH measurement, U. V. spectrophotometric method, and cryoscopic method. A. By cryoscopic method: 1. Initially, HWO₄^- ions were found in dilute Na₂WO₄ solutions acidified with HClO₄. 2. The W₃O_(11)^(4-) ions appeared when the mole ratio of H^+/WO₄^(2-) was made to 1.05, and H₂W_(12)O_(40)^(6-) to 1.55. 3. And, similarly, W₂O_7^(2-) ions appeared at the mole ratios of the following values, 1.15, 1.25, 1.30, and 1.35. B. By pH measurement: 1. The HWO₄^- ion appeared in the solutions whose pH values were maintained from 3.7 to 6.5. 2. And W₂O_7^(2-) ions formed at the pH values ranging from 3.8 to 6.3, W₃O_(11)^(4-) ions at 6.35 and H₃W_(6)O_(21)^(3-) or H₂W_(12)O_(40)^(6-) ions at 3.2. C. By U. V. spectrophotometric method: The U. V. absorption band due to HWO₄^- ions observed to range from 335 to 430 mμ in wave length, W₂O_7^(2-) isons from 345 to 435 mμ, W₃O_(11)^(4-) ions from 350 to 440 mμ, and H₂W_(12)O_(40)^(6-) ions from 368 to 457 mμ.