오스테나이트계 스테인리스강의 진동감쇠능에 미치는 ε 마르텐사이트의 영향

손동욱,김재환,김익수,Miyahara Kazuya,성장현,강창룡 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.8

The effect of the phases of y, α' and ε martensites, which constitute the structure of the 316L stainless steel with austenite structure at room temperature, on the damping capacity at room temperature has been investigated. As a result, various fractions of these phases were formed depending on the degree of cold work. The largest volume fraction of a martensite phase is obtained by 20% cold rolling and showed the highest damping capacity. The damping capacity is strongly controlled by the volume fraction of ε martensite with linear relationship, while the other phases of α' and r have actually no effect on the damping capacity.

針葉樹樹皮 溫水抽出物의 Trichoderma sp. 菌絲生育抑制效果

孫東元,金思翼,吳正壽 동국대학교 생명자원과학대학 연습림 1993 연습림논문집 Vol.- No.3

This study was carried out to get the reduction effect of mycelial growth on the bark hot­extractives of Pinus densiflora and Quercus aliena to the shiitake mushroom such as growth inhibitor, Trichoderm viride, Tricoderma harzianum. The obtained results are as follows ; As growing the concentration of hot­extractives the reduction effect of mycelial showed high reduction effect regardless of tree species. When it added 1% of the bark hot­extractives of Pinus densiflora, it showed 36%, 53% of reduction effect at Tr. viride, Tr. harzianum respectively. And at Quercus aliena it showed 38%, 46% at Tr. viride, Tr. harzianum respectively. The reduction effect of mycelial growth of authentic (+)­catechin at Tr. viride, Tr. harizianum showed 32%, 36%, respectively. And tannic acid at Tr. viride, Tr. harzianum showed 60%, 76%, respectively. The bark hot­extractives of sorft­wood showed reduction effect range from 36% to 53% to shiitake mushroom growth inhibitor and it considered that poly­flavanols which some kinds of tannin compound were responsible for the reduction effect.

褐色腐朽菌 Tyromyces palustris와 白色腐朽菌 Coriolus versicolor의 腐朽型 比較

孫東元,金思翼,吳正壽 동국대학교 생명자원과학대학 연습림 1995 연습림논문집 Vol.- No.4

This study was carried out to examine decay type with Brown-rot fungi, Tyromyces palustirs and White-rot fungi. Coriolus versicolor via the applications of ultrastructual, physical, and chemical methods. The results was following; When these fungi were cultured on wood blocks for the period of 30days, weightloss was 13.7% in T. palustris and 15.3% in C. versicolor whereas the weightloss was 24.3% in T. palustris/ 33.5% in C. versicolor for the culture of 60 days. Therefore, the weightloss of white rot fungi was greater than that of brown rot fungi. Holocellulose contents of wood blocks were 25.0% in T. palustris, 5.0% in C.versicolor for 30 days whereas 35.4% in C. versicolor in 7.9% for 60 days. Therefore, the utilization of holocelluose in T. palustris was greater than in C. versicolor. In case of the observation of SEM, degradation process of cell wall was rapid in T. palustris. Decrease rates of stress (parallel to grain) were 16.9% in T. palustris and 0.5% in C. versicolor for 15 days whereas for T. palustris was 20.3% and C. versicolor was 7.6% for 30 days. Therefore, T. palustris was higher rate of stress than C. versicolor. As a latter study, the causes of above differences were also concentrated on non-enzymatic decay mechanism.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Structural and optical properties of Cu₂O nanoparticles formed on Al₂O₃ substrates using spin coating and thermal treatment

Ick Son, Dong,Hyun Oh, Do,Kim, Tae Whan Elsevier 2010 Physica E, Low-dimensional systems & nanostructure Vol.43 No.1

<P><B>Abstract</B></P><P>Cu<SUB>2</SUB>O nanoparticles were grown on Al<SUB>2</SUB>O<SUB>3</SUB> substrates by spin coating and thermal treatment. X-ray diffraction patterns, scanning electron microscopy images, X-ray energy dispersive spectroscopy profiles, and high-resolution transmission electron microscopy images showed that Cu<SUB>2</SUB>O nanoparticles were formed on Al<SUB>2</SUB>O<SUB>3</SUB> substrates. The photoluminescence (PL) peaks at 30K were attributed to the excitonic peaks corresponding to interband transitions in the Cu<SUB>2</SUB>O nanoparticles, and the PL peak at 300K was related to the optical phonons in the nanoparticles.</P>

White light-emitting diodes fabricated utilizing hybrid polymer–colloidal ZnO quantum dots

Son, Dong Ick,You, Chan Ho,Kim, Won Tae,Kim, Tae Whan IOP Pub 2009 Nanotechnology Vol.20 No.36

<P>White light-emitting diodes (WLEDs) with a hybrid poly <I>N</I>-vinylcarbazole (PVK) and poly(methyl methacrylate) (PMMA) polymer and ZnO quantum dots (QDs) were fabricated by a spin-coating technique. Transmission electron microscopy images showed that the ZnO QDs were predominantly distributed at the circumference of the surface of the PVK polymer. Electroluminescence spectra for hybrid polymer–QD WLEDs showed a broad peak around 600 nm. The Commission Internationale de I’Eclairage chromaticity coordinates of the WLEDs fabricated utilizing hybrid polymer–QD WLEDs at 10 V were (0.39, 0.41), indicative of a white emission. The luminescence mechanisms of the WLEDs are described.</P>

Carrier transport in flexible organic bistable devices of ZnO nanoparticles embedded in an insulating poly(methyl methacrylate) polymer layer

Son, Dong-Ick,Park, Dong-Hee,Choi, Won Kook,Cho, Sung-Hwan,Kim, Won-Tae,Kim, Tae Whan IOP Pub 2009 Nanotechnology Vol.20 No.19

<P>The bistable effects of ZnO nanoparticles embedded in an insulating poly(methyl methacrylate) (PMMA) polymer single layer by using flexible polyethylene terephthalate (PET) substrates were investigated. Transmission electron microscopy (TEM) images revealed that ZnO nanoparticles were formed inside the PMMA polymer layer. Current–voltage (<I>I–V</I>) measurement on the Al/ZnO nanoparticles embedded in an insulating PMMA polymer layer/ITO/PET structures at 300 K showed a nonvolatile electrical bistability behavior with a flat-band voltage shift due to the existence of the ZnO nanoparticles, indicative of trapping, storing, and emission of charges in the electronic states of the ZnO nanoparticles. The carrier transport mechanism of the bistable behavior for the fabricated organic bistable device (OBD) structures is described on the basis of the <I>I–V</I> results by analyzing the effect of space charge.</P>

Emissive ZnO-graphene quantum dots for white-light-emitting diodes

Son, Dong Ick,Kwon, Byoung Wook,Park, Dong Hee,Seo, Won-Seon,Yi, Yeonjin,Angadi, Basavaraj,Lee, Chang-Lyoul,Choi, Won Kook Springer Science and Business Media LLC 2012 Nature nanotechnology Vol.7 No.7

Nonvolatile Flexible Bistable Organic Memory (BOM) Device with Au nanoparticles (NPs) embedded in a Conducting poly N-vinylcarbazole (PVK) Colloids Hybrid

Dong Ick Son,Byoung-Wook Kwon,Dong Hee Park,Jeong-Do Yang,Won Kook Choi 한국진공학회 2011 한국진공학회 학술발표회초록집 Vol.40 No.0

Polymer–ultrathin graphite sheet–polymer composite structured flexible nonvolatile bistable organic memory devices

Son, Dong Ick,Shim, Jae Ho,Park, Dong Hee,Jung, Jae Hun,Lee, Jung Min,Park, Won Il,Kim, Tae Whan,Choi, Won Kook IOP Pub 2011 Nanotechnology Vol.22 No.29

<P>We present data, which were obtained before bending and after bending, for the electrical bistabilities, memory stabilities, and memory mechanisms of three-layer structured flexible bistable organic memory (BOM) devices, which were fabricated utilizing the ultrathin graphite sheets (UGS) sandwiched between insulating poly(methylmethacrylate) (PMMA) polymer layers. The UGS were formed by transferring UGS (about 30 layers) and using a simple spin-coating technique. Transmission electron microscopy (TEM) measurements were performed to investigate the microstructural properties of the PMMA/UGS/PMMA films. Current–voltage (<I>I</I>–<I>V</I>) measurements were carried out to investigate the electrical properties of the BOM devices containing the UGS embedded in the PMMA polymer. Current–time (<I>I</I>–<I>t</I>) and current–cycle measurements under flat and bent conditions were performed to investigate the memory stabilities of the BOM devices. The memory characteristics of the BOM maintained similar device efficiencies after bending and were stable during repeated bendings of the BOM devices. The mechanisms for these characteristics of the fabricated BOM are described on the basis of the <I>I</I>–<I>V</I> results. </P>