단결정 반금속 비스무스 단일 나노선의 Shubnikov-de Haas 진동

김정민,함진희,심우영,이경일,전계진,정원용,이우영,Kim, Jeong-Min,Ham, Jin-Hee,Shim, Woo-Young,Lee, Kyoung-Il,Jeon, Kye-Jin,Jeung, Won-Young,Lee, Woo Young 한국재료학회 2008 한국재료학회지 Vol.18 No.2

The magneto-transport properties of an individual single crystalline Bi nanowire grown by a spontaneous growth method are reported. A four-terminal device based on an individual 400-nm-diameter nanowire was successfully fabricated using a plasma etching technique that removed an oxide layer that had formed on the surface of the nanowire. Large transverse ordinary magnetoresistance (1401%) and negative longitudinal ordinary magnetoresistance (-38%) were measured at 2 K. It was observed that the period of Shubnikov-de Haas oscillations in transverse geometry was $0.074^{T-1}$, $0.16^{T-1}$ and $0.77^{T-1}$, which is in good agreement with those of bulk Bi. However, it was found that the period of SdH oscillation in longitudinal geometry is $0.24^{T-1}$, which is larger than the value of $0.16^{T-1}$ reported for bulk Bi. The deviation is attributable to the spatial confinement arising from scattering at the nanowire surface boundary.

Ceromer (Targis)에 의한 법랑질 마모에 관한 연구

김정민,이선형,양재호,Kim, Jeong-Min,Lee, Sun-Hyung,Yang, Jae-Ho 대한치과보철학회 2000 대한치과보철학회지 Vol.38 No.4

The ideal restorative material should mimic the properties of the tissues it replaces. Dental composite resins have been used widely as restorative materials due to its advantages such as excellent esthetics and ease of manipulation. But inadequate wear resistance has been a major factor limiting the use of composite restorative materials. Improved manufacturing techniques have allowed the development of hybrid composites, with a greater percentage volume filler loading, which have improved physical and mechanical properties. However they are lacking in the study of wear resistance. The purpose of this study was to evaluate the wear of human enamel against ceromer by the use of a pin-on-disk type wear testers. Discs of ceromer(Targis ; lvoclar Vivadent, Amherst. NY) and discs of type III gold alloy as a control were used f9r test specimens. Intact cusp of premolar and molar were used for enamel specimens. The wear of enamel was determined by weigh-ing the cusp before and after each test, and the weight converted to volumes by average densi-ty of enamel. Surface profilometer was used to quantify wear of the ceromer and gold specimens. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces The results were as follows; 1. Ceromer produced less enamel wear than gold(p<0.05) 2. The wear volume of ceromer was greater than that of gold(p<0.01) 3. The hardess of ceromer was lower than that of gold, but there was no correlation between the hardness and wear of the ceromer and gold. 4. SEM analysis revealed that there were many voids and microcracks in the wear tract of ceromer In gold group, many minute V-shaped grooves were examined.

레이저 표면 용융공정으로 Al-Cr 코팅한 Zr합금의 미세조직 특성

김정민,이재철,김일현,김현길,Kim, Jeong-Min,Lee, Jae-Cheol,Kim, Il-Hyun,Kim, Hyun-Gil 한국재료학회 2017 한국재료학회지 Vol.27 No.10

In this study, the coating of an Al-Cr layer on the surface of a Zircaloy-4 alloy was carried out through plasma pretreatment coating and a laser surface melting process. Two different conditions for laser treatment, severe or minimal surface melting of the Zr alloy substrate, were applied to form the final coating. When there was significant surface melting of the Zr alloy, the solidification microstructure of the newly formed coating layer was mainly composed of needle-shaped $Al_3Zr$, Al(Cr) and $Al_7Cr$ phases. On the other hand, the solidification microstructure of the coating layer was mainly composed of Al(Cr) and $Al_7Cr$ phases when there was minimal surface melting of Zr base in the laser process. However, when the coating was maintained at $1100^{\circ}C$ for 2 hours, significant inter-diffusion occurred between the phases in the coating. As a result, the upper part of the coating layer was observed to mainly consist of $Al_3Zr$ and $Al_8Cr_5$ phases, regardless of the laser treatment conditions.

바디 구동 차동 입력단과 Self-cascode 구조를 이용한 0.5 V 2단 연산증폭기 설계 및 제작

김정민,이대환,백기주,나기열,김영석,Gim, Jeong-Min,Lee, Dae-Hwan,Baek, Ki-Ju,Na, Kee-Yeol,Kim, Yeong-Seuk 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.4

This paper presents a design and fabrication of 0.5 V two stage operational amplifier. The proposed operational amplifier utilizes body-driven differential input stage and self-cascode current mirror structure. Cadence Virtuoso is used for layout and the layout data is verified by LVS through Mentor Calibre. The proposed two stage operational amplifier is fabricated using $0.13{\mu}m$ CMOS process and operation at 0.5 V is confirmed. Measured low frequency small signal gain of operational amplifier is 50 dB, power consumption is $29{\mu}W$ and chip area is $75{\mu}m{\times}90{\mu}m$.

일본뇌염바이러스의 Mutant M 단백질에 반응하는 다클론항체의 생산: 극성 아미노산 잔기의 바이러스 생산과정에서의 역할

김정민,윤상임,송병학,김진경,이영민,Kim, Jeong-Min,Yun, Sang-Im,Song, Byung-Hak,Kim, Jin-Kyoung,Lee, Young-Min 한국미생물학회 2010 미생물학회지 Vol.46 No.2

일본뇌염바이러스(Japanese encephalitis virus)는 모기 매개성 플라비바이러스에 속하며, 주로 동남아시아 지역에서 유행성 바이러스성 뇌염을 일으킨다. 일본뇌염바이러스는 외피를 가진 작은 바이러스로서, 양성가닥 RNA 게놈을 가지고 있다. 감염성을 띤 바이러스 입자는 capsid (C), membrane (M; prM 전구체로부터 생성), 및 envelope (E)과 같은 3개의 구조단백질로 이루어져 있다. 본 연구에서는 일본뇌염바이러스 생산과 정에 M 단백질의 N-말단부위에 위치한 극성 아미노산 잔기의 역할을 분석하였다. 일본뇌염바이러스의 infectious cDNA를 활용하여, M 단백질의 $E^9$와 $K^{15}K^{16}E^{17}$ 잔기를 알라닌으로 치환시킨 2개의 mutant cDNA (Mm1과 Mm2)를 각각 제작하였다. 각각의 cDNA로부터 합성된 mutant RNA를 세포에 트랜스펙션시킴으로써, 비록 세포 내에 축적된 3개의 구조단백질양은 변화가 없으나, 이들 세포로부터 생산된 바이러스의 양은 Mm2 RNA의 경우 ~1,000배 감소됨을 관찰하였다. 흥미롭게도, Mm2 RNA로부터 발현된 mutant M 단백질은 wild-type M 단백질을 인지하는 항혈청에는 반응하지 않았으나, mutant M 단백질을 항원으로 제작된 항혈청에는 반응하는 것을 알 수 있었다. 본 실험결과는 일본뇌염바이러스 M 단백질을 구성하는 3개의 극성 아미노산 잔기($K^{15}K^{16}E^{17}$)가 바이러스의 생산과정에 관여한다는 것을 암시한다. 앞으로, wild-type 또는 mutant M 단백질(Mm2)을 인식하는 2개의 항혈청은 이 단백질의 기능연구에 유용한 재료로 사용될 것으로 기대된다. Japanese encephalitis virus (JEV), a member of the mosquito-borne flaviviruses, causes epidemics of viral encephalitis in the Southeastern Asia. JEV is a small enveloped virus with a positive-sense RNA genome; the infectious virion consists of three structural proteins, namely capsid, membrane (M; a mature form of its prM precursor), and envelope proteins. Here, we investigated a role of the charged residues found at the N-terminus of the JEV M protein in virus production. Using an infectious JEV cDNA, we generated two mutant cDNAs, Mm1 and Mm2, by charged-to-alanine substitution for $E^9$ and $K^{15}K^{16}E^{17}$ residues of the M protein, respectively. By transfection of wild-type or each of the two mutant RNAs transcribed from the corresponding cDNAs, we found that Mm2, but not Mm1, had a ~3-log decrease in virus production, even though a comparable amount of all three structural proteins were produced in transfected cells. Interestingly, the prM protein expressed in Mm2 RNA-transfected cells was not recognized by the polyclonal antiserum raised against the N-terminal 44 amino acids of the wild type M protein, but reacted to the antiserum raised against the corresponding region of the mutant Mm2. Our results indicate that three charged residues ($K^{15}K^{16}E^{17}$) in JEV M protein play a role in virus production. Two polyclonal antisera specifically recognizing the wild-type or Mm2 version of the M protein would provide a useful reagent for the functional study of this protein in the virus life cycle.

타이어 구름저항에 따른 EV 에너지 소비 주행특성에 관한 연구

김정민(Jeong-Min Kim),권성진(Seong-Jin Kwon),정승환(Seung-Hwan Chung),이봉현(Bong-Hyun Lee),김종찬(Jong-Chan Kim),이경민(Kyung-Min Lee) 한국자동차공학회 2012 한국자동차공학회 부문종합 학술대회 Vol.2012 No.5

In this paper, eight(8) different tires are tested which have different tire structures. From the test results, eight(8) different tire rolling resistance coefficients are found. To find an effect of tire rolling resistance coefficient on electric vehicle energy consumption, energy consumption simulations are performed using EV(Electric Vehicle) simulator. The simulations are performed by eight(8) different rolling resistance coefficient and four(4) different driving cycles. From the simulation results, it is found that the difference of energy consumption can be about 9 percent between different two tire rolling resistance coefficients for the electric vehicle.

타이어 구름저항이 하이브리드 전기자동차 연비에 미치는 효과 분석

김정민(Jeong-Min Kim),권성진(Seong-Jin Kwon),정승환(Seung-Hwan Chung),이봉현(Bong-Hyun Lee),김종찬(Jong-Chan Kim),이경민(Kyung-Min Lee) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11

In this paper, to find an effect of tire rolling resistance coefficients on hybrid electric vehicle (HEV) fuel efficiency, the HEV simulator has been developed. The tire rolling resistance coefficient depends on the diverse tire structure. For the purpose, the HEV simulations are performed by eight(8) different rolling resistance coefficients and four(4) different driving cycles. From the simulation results, it is found that the fuel efficiency can be improved about 5 percent by using the lower rolling resistance tire.

에어 스프링 적용 EV 차량의 피칭 제어에 관한 연구

김정민(Jeong-Min Kim),권성진(Seong-Jin Kwon),정승환(Seung-Hwan Chung),이동원(Dong-Won Lee),이봉현(Bong-Hyun Lee) 한국자동차공학회 2013 한국자동차공학회 학술대회 및 전시회 Vol.2013 No.11

능동형 스태빌라이저의 제어 시뮬레이션에 관한 연구

김정민(Jeong-Min Kim),권성진(Seong-Jin Kwon),정승환(Seung-Hwan Chung),이동원(Dong-Won Lee),이봉현(Bong-Hyun Lee) 한국자동차공학회 2014 한국자동차공학회 부문종합 학술대회 Vol.2014 No.5

단일 기관에서 장기 치료한 복막투석과 혈액투석 환자의 치료 경과 비교

김정민 ( Jeong-min Kim ),이세진 ( Se-jin Lee ),서동균 ( Dong-kyun Seo ),이기영 ( Ki-young Lee ),류상열 ( Sang Ryol Ryu ),이소영 ( So-young Lee ) 대한내과학회 2017 대한내과학회지 Vol.92 No.1

목적: 투석을 시작한지 3년이 지났으며 잔여 신기능이 없어졌다고 생각되는 환자들의 혈액투석 치료와 복막투석 치료 간의 치료 경과를 비교하였다. 대상 및 방법: 을지병원에서 36개월 이상 투석 치료를 받는 투석 환자를 대상으로 하였다. 대상 환자들의 의무기록을 조사하였고, 검사실 소견을 평균하여 기록하였다. 투석 적절도와 체수분량을 측정하였고 염증성 사이토카인을 측정하여 치료 방법에 따른 차이를 비교하였다. 결과: 총 80명의 환자 중 복막투석 환자 39명, 혈액투석환자 41명이었고 두 군 간에 평균 연령, 남녀비에는 차이가 없었다. 혈액투석 환자의 경우 97.5%의 환자가 Kt/V 1.2 이상을 만족하였으나 복막투석 환자의 경우 58%만이 이 기준을 만족하였다. 복막투석 환자가 더 BMI가 높았고 중성지방 수치가 높았으며 저밀도콜레스테롤이 높은 경향을 보였고 두군 간의 수분 조절 상태에 큰 차이는 없었다. 염증 수치는 Kt/V가 1.7 미만, 저투과도를 보이는 복막투석 환자군에서 더 의미 있게 높게 측정되었다. 결론: 장기 복막투석 환자의 경우, 혈액투석에 비해 효율적인 투석 적절도 유지가 어렵다. 이러한 투석 효율의 감소가 복막투석 환자를 상대적인 과염증 상태에 이르게 하는 원인이 될 수 있다고 생각된다. 따라서 장기 복막투석 환자의 경우, 투석 효율을 높이고 관리가 철저히 이루어질 수 있도록 환자 교육과 의료진의 관심이 더욱 필요한 치료군이라고 생각된다. Background/Aims: Improvements in dialysis therapies and patient care are leading to more patients receiving dialysis for longer periods of time. Survival rates with peritoneal dialysis (PD) are superior to those with hemodialysis (HD) during the initial 2-3 years; however, data comparing the outcomes of these two methods are lacking. Thus, we performed a retrospective study of patients treated with dialysis for longer than 3 years to investigate patient condition according to mode of dialysis. Methods: A total of 80 patients currently being treated by dialysis for at least 36 months at the Eulji Medical Center were included in this study. Patients` laboratory data and admissions histories over the prior 3 years were reviewed. Dialysis adequacy, body composition, and cytokine levels were quantified. Results: A total of 39 PD and 41 HD patients, with no difference in mean age or gender, were compared. Regarding dialysis adequacy, 97.5% of HD patients met the criterion of 1.2 Kt/V or higher, whereas only 58% of PD patients satisfied the required weekly Kt/V of 1.7. Inflammatory cytokines were significantly elevated in PD patients; however, PD patients with adequate dialysis expressed the same inflammatory cytokines as HD patients. Conclusions: The delivery of adequate dialysis to PD patients over extended periods of time is difficult. Thus, more rigorous management of PD patients is required to avoid insufficient dialysis and inflammation. (Korean J Med 2017;92:45-52)