Synthesis of Ce-doped In2O3 nanoparticles via a microwave-assisted hydrothermal pathway and their application as an ultrafast breath acetone sensor

유병훈,윤성도,나찬웅,윤지욱 한국표면공학회 2023 한국표면공학회지 Vol.56 No.6

Acetone, a metabolite detected from the exhaled breath of people doing a diet, can be used for non-invasive monitoring of diet efficiency. Thus, gas sensors with rapid response and recovery characteristics to acetone need to be developed. Herein, we report ultrafast acetone sensors using Ce-doped In2O3 nanoparticles prepared by the one-pot microwave-assisted hydrothermal method. The pure In2O3 sensor shows a high response and fast response time (τres = 6 s) upon exposure to 2 ppm acetone at 300 ℃, while exhibiting a relatively sluggish recovery speed (τrecov = 1129 s). When 20 wt% Ce is doped, the τrecov of the sensor significantly decreased to 45 s withholding the fast-responding characteristic (τres = 6 s). In addition, the acetone response (resistance ratio, S) of the sensor is as high as 5.8, sufficiently high to detect breath acetone. Moreover, the sensor shows similar acetone sensing characteristics even under a highly humid condition (relative humidity of 60%) in terms of τres (6 s), τrecov (47 s), and S (4.7), demonstrating its high potential in real applications. The excellent acetone sensing characteristics of Ce-doped In2O3 nanoparticles are discussed in terms of their size, composition, phase, and oxygen adsorption on the sensing surface.

VBA 개체의 속성 체크 방법

유병훈 한국산업비즈니스학회 2018 한국산업비즈니스학회 학술대회 발표집 Vol.2018 No.6

간기능 저하 및 황달을 동반한 다발성 전이 유상피 혈관내피종의 치료

유병훈,이혜원 대한내과학회 2021 대한내과학회 추계학술대회 Vol.2021 No.1

Experimental study on the effects of the number of heat exchanger modules on thermal characteristics in a premixed combustion system

유병훈,금성민,이창언,Seungro Lee 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

The effects of the number of heat exchanger modules on thermal characteristics were experimentally studied in a premixed combustionsystem with a cross-flow staggered-tube heat exchanger. The various heat exchanger modules, from 4 to 8, combined with a premixedburner were tested to investigate the performance of the heat exchanger through the surface area of the heat exchanger at various equivalenceratios. Additionally, the performance of the heat exchanger was analyzed by applying entropy generation theory to the heat exchangersystem. As a result, although the heat transfer rate increases with the increase of the equivalence ratio, the NOx and CO concentrationsalso increase due to the increasing flame temperature. In addition, the entropy generation increases with an increase of theequivalence ratio. Furthermore, the heat transfer rate and the effectiveness are increased with the increase of the number of the heat exchangermodules. Also, the effectiveness is sharply increased when the number of the heat exchanger modules is increased from 4 to 5. Consequently, the optimal operating conditions regarding pollutant emission, effectiveness and entropy generation in this experimentalrange are 0.85 for the equivalence ratio and 8 for the number of heat exchanger modules.

수학교육을 위한 웹 기반 진단-형성평가 시스템의 개발과 활용

유병훈,강수구 한국수학교육학회 2003 수학교육 Vol.42 No.5

In this paper, we studied how to organize and develop a web based diagnostic-formative evaluation system. We investigated the interest of students about the system and analyze their scores after we applied this system to 10-th grade students for 10 months.

怡樂村肺吸蟲에 있어서의 Sarles 現象에 關한 硏究

兪炳勳,宋哲鏞,李純炯 중앙대학교 의과대학 의과학연구소 1977 中央醫大誌 Vol.2 No.1

The experiment was designed to understand the humoral immune response of albino rat host against Paragonimus iloktsuenensis infection by demonstrating the Sarles' phenomenon. Rats of experimental groups were infected with the metacercariae of P. iloktsuenensis which were isolated from brackish water crab, Sesarma dehaani, and were kept for 3 days, 4 weeks, 10 weeks and 14 weeks of infection period. After the given infection period, live excysted metacercarise of P. iloktsuenensis mixed with the serum of the infected rats were placed on the hole glass slide and incubated at 37℃. These slides were examined microscopically at 24 hours and 48 hours after incubation. Control groups were consisted of 1) uninfected rats, 2) uninfected rats injected intramuscularly with prednisolone 10㎎/㎏ every other day, 3) infected rats injected intramuscularly with prednisolone 10㎎/㎏ every other day. Same procedures as experimental groups were carried on. The results obtained were as follows. 1) Precipitations were formed around the excysted metacercariae in the experimental groups. The precipitations were most prominent around the oral sucker. 2) Sarles' phenomenon was positive in all the experimental groups of 10 weeks and 14 weeks of infection period. 3) There were no correlations between the number of worms discovered at the infected rats and the intensity of the precipitate formation. 4) Sarles' phenomenon was negative in all the control groups.

Duchenne형 근이영양증 환아의 척추측만증 교정술 마취 1예

유병훈,이상석,연준흠,김정원,홍기혁 인제대학교 1998 仁濟醫學 Vol.19 No.1

Duchenne형 근이영양증 환자는 술중과 술후에 다양한 부작용이 발생할 수 있기 때문에 많은 주의를 요한다. 특히 전신마취에 흔히 사용되는 흡입마취제 및 Succinylcholine 등에 의해 쉽게 악성고열증에 빠지게 됨으로써 마취시에는 이들 약제의 사용 및 악성 고열증에 주의해야만 하며 또한 반드시 발생하는 심근에 대한 근이영양증 때문에 심혈관 부작용도 주의하여야 한다. 저자들은 척추측만증 교정술이 예정된 Duchenne형 근이영양증 환아에서 유발되는 요소를 제거하고 마취시에 안정하다고 알려진 약제들을 사용하여 악성 고열증 및 수술후의 부작용의 발생없이 성공적으로 마취를 시행하였기에 문헌고찰과 함께 보고하는 바이다. Patients with Duchenne muscular dystophy(DMD) are susceptible to numerous adverse intraoperative and postoperative side effects of anesthetic agents. One of the most serious side effect is malignant hyperthermia (MH). A succesful anesthesia were done in a patient with DMD with the drugs safe for malignnant hyperthemia. A 14 years old boy with DMD operated for spinal fusion under general anesthesia. We performed safe general anesthesia without instance of malignant hyperthermia and side effacts. The anesthetic management included primarily intravenous general anesthetics with minimal myocardial depressant effects, avoiding succinylcholine and inhalation agents. We used vecuronium for muscle relaxation, nitrous oxide, propofol and fentanyl.

실업계 고등학교 학생에 대한 효율적인 수학학습 지도방안에 관한 연구

유병훈,권민수 안동대학교 교육대학원 2005 교과교육연구논집 Vol.2 No.-

B형 간염 백신의 접종 횟수에 따른 항체 생성률에 대한 고찰

한혜경,엄미령,이성자,최경훈,이미나,유병훈 대한감염학회 1996 감염 Vol.28 No.1

목적 : B형 간염 혈장백신에 의한 항체 양성률은 90-95% 이상으로 보고되고있고 저자마다 결과의 차이가 있었다. 또한 동일개체 내에서 항체가 변화에 대한 연구가 많지 않아 저자들은 동일 개체에서의 시간경과에 따른 항체가 변화와 B형 간염백신접종 후 항체가 형성되지 않았던 아동들에게 백신 재접종 후 항체가와 항체양성률이 어떻게 변화하는지 알아보고자 본 연구를 시도하였다. 방법: 1994년 3월부터 1995년 6월까지 제일병원에서 B형 간염백신(HepavaxR)을 출생시, 1개월, 6개월에 접종받은 소아중 934명을 대상으로하여 생후 9개월에 항원(HBsAg), 항체가(Ant-HBs titer)를 측정하여 이중 항체가 형성되지 않은 소아에게 1회 추가접종후 4주후에 다시 항체가를 측정하였다. 이중 항체가 형성안된 소아에게 5차, 6차 접종후 3개월후에 다시 항체가를 측정하였다. 이들중 HBsAg양성 산모의 소아들에겐 생후 3개월 때 항원, 항체 검사를 실시 하였다. 검사방법은 RIA(radioimmunoassay:Abbott Laboratories)로 하였다. 결과: 1)2차 백신접종후(간염항원 양성 산모의 소아들중 생후 3개월인 소아) 검사한 HBsAb역가가 10mIU/ml 이상인 경우는 63명중 22명(34.9%)이었고 이중 항체가 형성안된 아동중 4차 접종후 검사가 시행된 172명중 101명(58.7%)이 10mIU/ml 이상이었다. 5차, 6차 백신접종후 검사가 시행된 13명중 4명이 10mIU/ml이상이었다. 2) 4차 백신 접종후 누적 항체양성률은 90.8%였고, 6차 백신 접종후는 98.7%였다. 결론: 3차 백신 접종후 항체 음성인 소아에게 4차 접종후 항체양성률이 증가되었다. B형 간염 백신 3차 접종후 선별 검사를 실시하여 항체 음성인 아동에게 추가접종이 필요할것으로 생각된다. Background : The seroconversion rate of hepatitis B after three consecutive vaccinations is estimated to be approximately 90%. We have given booster injections to the seronegative children with the fourth, fifth or sixth vaccination and estimated the seroconversion rate of hepatitis B (?? : Korean Green Cross Corporation) in relation to the number of vaccination. Methods : Serum samples were obtained from 934 babies who visited Cheil Hospital at 9 months of age (3 months after the 3rd vaccination) to determine the presence of HBsAg and titer of anti-HBs. The cases of negative anti-HBs were given a booster dose and anti-HBs titer was tested 4 weeks later. The babies who still had negative anti-HBs after the 4th dose were given the 5th and the 6th doses and anti-HBs titer was tested. RLA (Abbott Laboratories, U.S.A.) was used to determine the titers of anti-HBs. Seventy-eight babies born yo mothers who were HBsAg-positive were tested for HBsAg and titers of anti-HBs at 3 months of age after the 2nd vaccination. Results: 1) Twenty-two babies out of 64(34.9%) showed seroconversion after the 2nd vaccination. Six hundred babies out of 893(67.2%) showed seroconversion after the 3rd vaccination. Among the babies who were given the 4th dose 101 out of 172 (58.7%) babies showed seroconversion and for the 6th dose 4 out of 13 babies. 2) Cumulative seroconversion rate was 90.8% and 98.7% after the 4th and 6th vaccination, respectively. 3) The geometric mean titer (GMT) of anti-HBs was 19.2mIU/ml after the 2nd vaccination, 112.7mIU/ml after the 3rd vaccination and 57.1mIU/ml after the 4th vaccination. Conclusion : Seroconversion rate increased after the 4th dose for the babies who had negative anti-HBs even after the 3rd vaccination. Therefore, we recommend to screen for anti-HBs after the 3rd vaccination and to give booster injections for those who are negative anti-HBs.

터널 화재에서 연기거동에 관한 실험적 연구

유병훈,황철홍,이창언,김정엽,신현준 한국화재소방학회 2004 한국화재소방학회 학술대회 논문집 Vol.2004 No.추계