Engineering of AlON interlayer in Al₂O₃/AlON/In_0.53Ga_0.47As gate stacks by thermal atomic layer deposition

Lee, Woo Chul,Cho, Cheol Jin,Park, Suk-In,Jun, Dong-Hwan,Song, Jin Dong,Hwang, Cheol Seong,Kim, Seong Keun ELSEVIER 2018 CURRENT APPLIED PHYSICS Vol.18 No.8

<P>The presence of an AlN interfacial layer in high-k/In0.53Ga0.47As gate stacks improves the interfacial properties and enhances the electrical performance of devices. However, pure AlN is rarely grown by atomic layer deposition (ALD) because of the low reactivity of NH3 toward the common Al-precursor and the predisposition to oxidation of the grown AlN layer. Although a plasma-enhanced ALD technique significantly suppresses the oxygen content in the grown AlN layer, the deterioration of the interface properties by plasma-damage is a critical issue. In this work, an AlON interlayer was engineered by optimizing the NH3 feeding time in thermal ALD to improve the interface quality in Al2O3/AlON/In0.53Ga0.47As capacitors. It was determined that a mere increase in the NH3 feeding time during the ALD of the AlON film resulted in a higher nitrogen incorporation into the AlON interlayer, leading to a reduction in the interface trap density. Furthermore, the out-diffusion of elements from the In0.53Ga0.47As layer was effectively suppressed by increasing the NH3 feeding time. This work demonstrates that simple process optimization can improve the interface quality in high-k/In0.53Ga0.47As gate stacks without the use of any plasma-activated nitrogen source.</P>

부산시내 대중목욕탕 용수중 중금속 분석

황인철,권미애,탁효정 고신대학교 보건과학연구소 2000 보건과학연구소보 Vol.10 No.-

The niny-four cold and hot water samples were collected from 47 bathhouses in Pusan and then analyzed by ICF with microwave digestion treatment to evaluate 13 kinds of metals in water of public baths. The mean concentrations of each metal in all samples were Pb, 0.001 mg/L; Ca, 33.241 mg/L; Fe, 0.066 mg/L; Mg, 5.166 mg/L; Zn, 0.040 mg/L; As, 0.009 mg/L; Mn, 0.006 mg/L; Cd, 0.007 mg/L; Se, 0.002 mg/L; Cr; 0.025 mg/L; Al, 0.047 mg/L; Cu, 0.032 mg/L. In groundwater samples Ca, Mn and Cu and Al level showed a statistically significant degree (p<0.01). In tap water samples Pb and Fe level were significantly hider in cold water while the Cr and Al level were lower (p<0.05). In the mixed tap groundwater and the spa water samples no significant degree was found between cold and hot water except that Mn level in cold water was significantly higer than in hot (p<0.05). Comparison between the spa area and non-spa area group : Ca and As level were higher in the spa area than the non-spa area, respectively. The highest mean concetration of Fe, Mg, Zn, and Cu were cold water in non-spa area, that of Mg and Cu were hot water.

수종의 역충전 재료의 치근단 밀폐력 비교

황윤찬,강인철,황인남,오원만 대한치과보존학회 2001 Restorative Dentistry & Endodontics Vol.26 No.5

This study was performed to evaluate the sealing ability of various retrograde filing materials by using bacterial penetration and dye penetration test. One hundred and forty extracted human teeth with single, straight canals and mature apices were collected and used for this study. All canals were instrumented using an engine driven Ni-Ti file (ProFile). After removing 3mm from the apex of tooth, a standardized 3mm root end cavity was prepared using an ultrasonic instrument. The 70 teeth were randomly divided into 7 groups : 6 groups for retrograde filling using Super-EBA, ZOE, Chelon-Silver, IRM, ZPC and amalgam. The 7th group was used as a negative control. Nail varnish was applied to all external root surfaces to the level of the resected root ends to prevent lateral microleakages. The specimens were then sterilized in an ethylene oxide sterilizer for 24 hours. 2 mm of the rejected root was immersed in a culture chamber containing a Tripticase Soy Broth with a phenol red indicator. The coronal access of each specimen was inoculated every 72 hours with suspension of Proteus vulgaris. The culture media were observed every 24hours for color change indicating bacterial contamination. The specimens were observed for 4weeks. The remaining 70 teeth were submitted to a dye penetration test. The canals of all teeth were first sealed with AH26 and obturated using an Obtura II system. Root resection, root end preparation and retrograde filling was performed as above. All specimens were suspended in 2% methylene blue dye for 72 hours before being longitudinally split. The degree of dye penetration was then measured using a stereomicroscope at 10 magnification and evaluated. The results were as follows : 1.In the bacterial penetration, the degree of leakage was the lowest in the Super-EBA, followed by, in ascending order, ZOE, Chelon-Silver IRM and ZPC. The amalgam showed highest bacterial leakage of all(p<0.01) . 2.In the dye penetration, the degree of microleakage was the lowest in the Chelon-Silver and Super-EBA, followed by, in ascending order, IRM, ZPC. The ZOE and amalgam showed the highest microleakage of all(p<0.05) . These results suggested that the eugenol based cement, Super-EBA, have excellent sealing ability as a retrograde filling material.

제주도 고등학교 학생들의 비만 정도, 심혈관 위험인자, 소아시 비만과의 관련성

홍성철,황승욱,현인숙 韓國保健敎育.健康增進學會 2003 보건교육건강증진학회지 Vol.20 No.2

Background: Recently, adolescent obesity was increased and tended to become obese adults, facing increased risk for diabetes, cardiovascular disease. Even before reaching adulthood, adolescent obesity already was experiencing hypertension, dyslipidemia, and diabetes mellitus. The purpose of this study was to find prevalence of obesity of high school students in Jeju island and association between obesity and cardiovascular risk factors and association between childhood obesity and adolescent obesity. Method: The study subjects were 6,064 students of twenty-two high school in Jeju island and health survey data was gathered from high school health examination data and hospital health examination data from Aug. 1999 to Dec. 1999. Adolescent obesity was evaluated by ideal body weight method in 1998 and body mass index. Cardiovascular risk factors were checked total cholesterol, systolic and diastolic blood pressure, fasting blood sugar. In 1,534 students, obesity at primary school is checked by primary and middle school health record. Results: Prevalence of obesity in Jeju island high school students is 12.6% in male students, 13.3% in female students by ideal body weight method and 8.7% in male students, 8.5% in female students by body mass index. Prevalence of obesity of male students in city area and district area of Jeju island were each 12.9%, 10.3% and that of male students in city area was significantly higher. Prevalence of obesity of female students in city area and district area of Jeju island were each 12.9%, 14.2% and not significantly different. Prevalence of obesity of male students in general and commercial school group were each 13.9%, 10.3% and that of general school group was significantly higher. In female students, Prevalence of obesity general and commercial school group was not significantly different. Total cholesterol, systolic and diastolic blood pressure were significantly associated with degree of obesity in male and female students(P<05) and fasting blood sugar was only significantly associated with degree of obesity in male students(P<05). In 1,514 students checked by health record, Odds ratio of obesity at primary and middle school that at high school were 12.96~22.77 and was significantly associated. Conclusion: Prevalence of obesity of high school students in Jeju island is very high and adolescent obsity was significantly associated with cardiovascular risk factors. Mostly childhood obesity tended to become adolescent obsity and program of control of obesity at childhood and adolescence is required.

Discriminative detection of indoor volatile organic compounds using a sensor array based on pure and Fe-doped In₂O₃ nanofibers

Lee, Chul-Soon,Li, Hua-Yao,Kim, Bo-Young,Jo, Young-Moo,Byun, Hyung-Gi,Hwang, In-Sung,Abdel-Hady, Faissal,Wazzan, Abdulaziz A.,Lee, Jong-Heun Elsevier 2019 Sensors and actuators. B Chemical Vol.285 No.-

<P><B>Abstract</B></P> <P>Representative indoor volatile organic compounds (VOCs) such as benzene, xylene, toluene, formaldehyde, and ethanol need to be detected in a highly sensitive and discriminative manner because of their different impact on human health. In this study, pure and 0.05, 0.1, 0.3, and 0.5 at% Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> nanofibers were prepared by electrospinning and their gas sensing characteristics toward the aforementioned VOCs were investigated. The doping of In<SUB>2</SUB>O<SUB>3</SUB> nanofiber sensor with 0.05 and 0.1 at% Fe shifted the temperature to show the maximum responses to benzene, xylene, and toluene, and reduced responses to ethanol and formaldehyde, thus demonstrating changed gas selectivity. The gas sensing characteristics of 0.5 at% Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> nanofiber sensor were substantially different from those of the other sensors. Significantly different gas sensing patterns of pure and Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> sensors could be used to discriminate between the five different VOCs at 375 °C and to distinguish between the aromatic and non-aromatic gases at all sensing temperatures. The mechanism underlying the Fe-induced change in gas sensing characteristics has been discussed in relation to the variation of catalytic activity, morphology, oxygen adsorption, and charge carrier concentration.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fabrication of a sensor array using pure and Fe-doped In<SUB>2</SUB>O<SUB>3</SUB> nanofibers. </LI> <LI> Discriminative detection of benzene, xylene, toluene, ethanol, and formaldehyde. </LI> <LI> Distinction between aromatic and non-aromatic indoor pollutants using sensor array. </LI> <LI> Gas sensing mechanism underlying Fe-induced change in response and selectivity. </LI> </UL> </P>

장시간 불가피한 공복(fasting)후 인체의 내분비 변화 : 삼풍백화점 붕괴 사고후 구조된 3인의 증례 THREE CASES IN COLLAPSE OF SAMPOONG DEPARTMENT STORE

박규남,황주일,박조현,오동렬,이원재,오승택,김세경,김인철 대한응급의학회 1995 대한응급의학회지 Vol.6 No.2

The interactions between nutrition and the endocrine system are more intimate and complex that previously thought. Nutrition modulates secretion and activity of many hormones, as part of the stress adaptation process. Fasting, in particular, produces a number of important changes in the endocrine system, with teleological purpose of helping the body tolerate the lack of food ingestion. These changes are therefore beneficial and protective, although at times they may not appear to be that way. The endocrine changes of fasting mediate the metabolic response. We must emphasize that these changes are completely reversible when appropriate nutrition is established. These changes are as followes: 1) decreased insulin and increased glucagon levels, 2) decreased thyroid effect, 3) decreased sympathetic activity, 4) hypothalamic hypogonadism, 5) decreased growth, 6) altered glucocorticoid secretion and metabolism, 7) impaired mineralocorticoid response, 8) decreased ADH secretion and effect. We experienced three cases of involuntary prolonged fasting after collapse of Sampoong department store. They were released from collapsed field after 11(case Ⅰ), 13(case Ⅱ), 17days(case Ⅲ) respectively. In each case, the endocrine changes of plasma levels were as followes: decrease of cortisol in case Ⅰ, increase of GH in case Ⅱ, decrease of free T3, T3, cortisol and increase of reverse T3, insulin in case Ⅲ. Each one did not show the same endocrine changes of plasma levels. But we think these changes of fasting are beneficial in metabolic response of human.

Optimal Timing of Percutaneous Coronary Intervention in Patients With Non–ST-Segment Elevation Myocardial Infarction Complicated by Acute Decompensated Heart Failure (from the Korea Acute Myocardial Infarction Registry-National Institutes of Healt

Kim, Min Chul,Jeong, Myung Ho,Sim, Doo Sun,Hong, Young Joon,Kim, Ju Han,Ahn, Youngkeun,Ahn, Tae Hoon,Seung, Ki Bae,Choi, Dong-Joo,Kim, Hyo-Soo,Gwon, Hyeon Cheol,Seong, In Whan,Hwang, Kyung Kuk,Chae, S Elsevier 2018 The American journal of cardiology Vol.121 No.11

<P>The optimal timing of percutaneous coronary intervention (PCI) in patients with non–ST-segment elevation myocardial infarction (NSTEMI), complicated by acute decompensated heart failure (ADHF), is unclear. A total of 1,027 patients with NSTEMI complicated by ADHF who underwent successful PCI were analyzed using a Korean multicenter registry. All patients were divided into 4 groups by the timing of PCI: group 1 (PCI < 2 hour after admission, n = 149), group 2 (2 to 24 hours, n = 577), group 3 (24 to 72 hours, n = 189), and group 4 (≥72 hours, n = 112). We analyzed the incidences of 12-month mortality, nonfatal myocardial infarction (MI), target-vessel revascularization, and rehospitalization because of HF. The prevalence of ADHF in patients with NSTEMI was 15.2% at initial presentation, and in-hospital mortality was higher in group 1 than in the other groups. There were no significant differences in mortality, nonfatal MI, target-vessel revascularization, or rehospitalization for HF during the 12-month follow-up between groups, regardless of initial PCI timing, except for a higher 12-month mortality in patients who received PCI within 24 hours (vs ≥24 hours) (hazard ratio 1.52, 95% confidence interval 1.09 to 2.29, p = 0.046). Early PCI did not reduce adverse clinical outcomes in patients with NSTEMI complicated by ADHF. Delayed PCI after stabilization may be reasonable in such high-risk patients.</P>

승산-누산기 유닛을 위한 in-situ 타이밍 모니터 기반의 적응형 주파수 스케일링 기법

황봉구(Bong-Gu Hwang),황인철(In-Chul Hwang) 대한전자공학회 2018 대한전자공학회 학술대회 Vol.2018 No.6

This paper presents An Adaptive Frequency Scaling Technic Based on In-situ Timing Monitor for Multiplier-Accumulator Unit. The short channel devices are becoming more vulnerable to local as well as global variations. Typically, the circuits are designed with wider voltage and frequency margins to withstand these variations. However, the performance of these circuits can be adversely affected in terms of speed and power due to these additional margins. Considering these issues, we present an in-situ timing detection technique which senses the timing of the critical path with the proposed timing monitor. In our structure, an 8-bit MAC unit models the critical path. The proposed AFS technique is deigned in 65-nm CMOS process.

Bacillus thuringiensis var. darmstadiensis 와 var. sotto의 내독소와 Bacillus thuringiensis var. kurstaki가 생산하는 아밀라제의 연구

이형환,김삼찬,황광현,임창로,조용칠,정인명 건국대학교 교육대학원 1991 敎育論叢 Vol.15 No.-

Endotoxin crystals produced by B.thuringiensis var. darmstadiensis cultured in modified GYS medium over 72 h were ovoidal in shape and separated using Renografin gradient centrifugation. The crystal protein bands were observed. When B.thuringiensis var sotto was grown in the modified GYS broth, it entered stationary phase at 8-9 h after inoculation. Proteinaceous crystals were banded at the position in 40% of Renografin gradient. The solubilized crystal proteins were formed by two bands, 130 Kd and 68 Kd in the SDS-PAGE. One plasmid was observed in B.thuringiensis var darmstadiensis and no plasmid in var. sotto in this study. Enzyme activity of amylase produced B.thuringiensis var kurstaki strain in the basal medium was 0.4 units per ml, and was enhanced to 0.6 units per ml in the basal medium contained soluble starch, Ca^++, Mg^++ and Mn^++ ions. Amylase production medium containing soluble starch was suitable for the amylase production and the highest activity appeared at 4-6 h after cultivation at 32℃. The amylase activity obtained by ethanol precipitation was 0.20 units per ml in 0.1 M phosphate buffer. The band of the molecular weight of 50 Kd was observed by SDS-PAGE analysis. Km value of the amylase for the soluble starch was 6.80 mg per ml.

직업성 경견완장애 진단시 생화학적 지표의 이용가능성

이용환,배강우,황인철,박강원,김영기 高神大學校保健科學硏究所 1998 보건과학연구소보 Vol.8 No.-

The increased incidence of occupational cervicobrachial disorder appears to be due to new technology, such as advanced automation and mechanization. That requested for worker's repetitive movements, which were limited to use upper extremities of body. Consequently, increased rate of work concentrated locally on an individual's musculoskeletal system that results in occupational cervicobrachial disorder. Though the occupational cervicobrachial disorders have been diagnosed by evaluating questionnares from the workers, objective and clear diagnostic criteria were not established. We tried to develope biochemical indicators that can be used in the dignosis and screening test of the occupational cervicobrachial disorders. The subjects who engaged in the shoemaker factory were divided into 3 groups by their workload; heavy(58 persons), repetitive(55 persons), and control workers(60 persons). The questionnare test was followed by biochemical examinations analyzing blood sample of the subjects. The biochemical indicators used were creatine kinase(CK), aspartate aminotransferase(AST), potassium, lactate, ammonia, uric acid, hypoxanthine, and malondialdehyde(MDA). The concentration of plasma MDA was highest in the heavy workers and there was statistically significant differences in the scores of the questionnare between the workers having concentrations within normal range and above normal range. Also, the levels of serum lactate, plasma uric acid and hypoxanthine were higher in heavy and repetitive workers than control, but, there were not any significant relationships among the groups in questionnare study. We concluded that these results would be applicable after more study on the standardized method in the analysis of the biochemical indicators and related other clinical tests.