Al-Mg-X (X=Cr, Si)합금의 기계적성질에 미치는 결정립크기와 시효조건의 영향

한창석 ( Chang-suk Han ),이찬우 ( Chan-woo Lee ) 한국열처리공학회 2023 熱處理工學會誌 Vol.36 No.2

In this study, the mechanical properties of the Al-Mg-X (X=Cr, Si) alloy, which clearly showed the influence of the specimen and grain size, were investigated by changing the specimen size extensively. In addition, the effect on the specimen size, grain size and aging condition on the mechanical properties of the grain refining alloy according to the addition of Cr was clarified, and the relationship between these factors was studied. As the specimen size decreased, the yield stress decreased and the fracture elongation increased. This change was evident in alloys with coarse grain sizes. Through FEM analysis, it was confirmed that the plastic deformation was localized in the parallel part of specimen S2. Therefore, when designing a tensile specimen of plate material, the W/L balance should be considered along with the radius of curvature of the shoulder. In the case of under-aged materials of alloys with coarse grain size, the fracture pattern changed from intergranular fracture to transgranular fracture as W/d decreased, and δ increased. This is due to the decrease in the binding force between grains due to the decrease in W. In the specimen with W/d > 40 or more, intergranular fracture occurred, and local elongation did not appear. Under-aged materials of alloys with fine grain size always had transgranular fracture over a wide range of W/d = 70~400. As W/d decreased, δ increased, but the change was not as large as that of alloys with coarse grain sizes. Compared to the under-aged material, the peak-aged material did not show significant dependence on the specimen size of σ_0.2 and δ. (Received February 10, 2023; Revised March 15, 2023; Accepted March 15, 2023)

열 플라즈마 인가 전류변화에 의한 ZrVFe 합금 나노분말의 제조특성에 관한 연구

한창석(Chang-Mik Han),정민희(Min-Hee Jung),김헌창(Heon-Chang Kim) 호서대학교 공업기술연구소 2007 공업기술연구 논문집 Vol.26 No.1

Plasma Display Panel (PDP), among various FPD’s, is considered as the most promising candidate for large area display due to its manufacturing process appropriate for a large displaying area, and a good display quality. The getter which can be continuously absorbed and eliminated the generated impurities gas such as O 2 , H 2 , CO, etc. from MgO, barrier rib and fluorescent substances during operation, should be installed in the PDP cell. As a result of install getter in the cell, we could obtain the extending the life time of the PDP with a good display quality. To manufacture getter possessing excellent absorption efficiency, it was produced particles of nano size. In this research, alloy nano powders are synthesized by transferred thermal plasma process which is a promising method to produce composite nano powders of various metals, and also provides high temperature environment(104 K), extremely fast and intense chemical reactions. In this study, the thermal plasma system was operated in a transferred mode and the raw material was used Zr, V ,Fe (57 : 35.8 : 7.2) alloy of ingot type which made from arc melting method, and the produced particles were analyzed according to changing plasma input current range from 120[A] to 160[A] by SEM, EDS, PSA, XRD, BET, PSA (Particle Size Analyzer) and BET analysis of particles synthesized by changing thermal plasma input current. Average size of particles is from 83.2[nm] to 47.8[nm] smaller, in result, we confirmed difference of approximately 35[nm] in diameter of the synthesized particle according to increasing plasma input current because particles was rapidly condensate from difference in temperature of between plasma column area of a high temperature and surround area of plasma column. Result of BET analysis is in inverse proportion to PSA result which has small value of particle diameter by increasing plasma input current. In case of 120[A], BET surface area of particle is 100.9[m2/g],and surface area of particle in condition of 160[A] is 211.2[m2/g]. Thus, as increasing plasma input current, BET surface area of the synthesized particle is more extend.

만성 정신분열증 환자에서 Paroxetine과 Haloperidol 병합투여시 정신병리증상과 Haloperidol, Reduced Haloperidol 혈중농도의 변화

한창수,이민수,김표한,Han, Chang Su,Lee, Min Soo,Kim, Pyo Han 대한생물정신의학회 1996 생물정신의학 Vol.3 No.2

Selective serotonin reuptake inhibitors(SSRIs), as haloperidol, ore metabolized in the cytochrome P450IID6. They can cause inhibition of metabolism of antipsychotics to elevate the serum level of antipsychotics and exacerbate the extrapyramidal symptoms when co-administered with antipsychotics. Among these SSRIs, there ore a few studies about paroxetine compared to fluoxetine or sertraline. In this study, we have intended to know the drug interaction of paroxetine and haloperidol when co-administered two drugs for the chronic schizophrenics by assessing the changes of positive, negative symptoms and extrapyramidal symptoms. for this purpose, we selected 29 subjects, the chronic schizophrenics with no physical problems. They were under maintenance therapy of haloperidol. They ore randomly assigned to placebo group(n=12) and drug group(n=17) by using double blind method. And then, placebo or paroxetine 20mg were administered to the subjects of each groups during 8 week period. We have assessed their psychopathology and extrapyramidal symptoms using Positive and Negative Syndrome Scale(PANSS), Hamilton Rating Scale lor Depression(HRSD), Simpson-Angus Scale at 0, 2, 4, 6, 8 weeks and serum haloperidol, reduced haloperidol levels at 0, 4, 8 weeks during the period. The results ore analysed by using repeated measure MANOVA. 27 subjects have completed the study during 8 weeks. among the subjects, 1) PANSS, HRSD ; no significant difference between groups. 2) Simpson-Angus Scale ; no significant change according to the time and no significant difference between the groups(no group and time effect). 3) Haloperidol and reduced haloperidol level ; no significant change. When co-administered paroxetine and haloperidol, there ore no significant changes of the psychopothology and no significant changes of the extrapyramidal symptoms. In this result, paroxetine seems to be not to affect the metabolism of haloperidol.

비정질상인 Ti₅Si₃ MA분말의 가압소결 동안 소결체의 치밀화 촉진현상 요인에 대한 조사

한창석,진성윤,권혁구,Han, Chang-Suk,Jin, Sung-Yooun,Kwon, Hyuk-Ku 한국재료학회 2020 한국재료학회지 Vol.30 No.6

In this study, factors considered to be causes of promotion of densification of sintered pellets identified during phase change are reviewed. As a result, conclusions shown below are obtained for each factor. In order for MA powder to soften, a temperature of 1,000 K or higher is required. In order to confirm the temporary increase in density throughout the sintered pellet, the temperature rise due to heat during phase change was found not to have a significant effect. While examining the thermal expansion using the compressed powder, which stopped densification at a temperature below the MA powder itself, and the phase change temperature, no shrinkage phenomenon contributing to the promotion of densification is observed. The two types of powder made of Ti-silicide through heat treatment are densified only in the high temperature region of 1,000 K or more; it can be estimated that this is the effect of fine grain superplasticity. In the densification of the amorphous powder, the dependence of sintering pressure and the rate of temperature increase are shown. It is thought that the specific densification behavior identified during the phase change of the Ti-37.5 mol.%Si composition MA powder reviewed in this study is the result of the acceleration of the powder deformation by the phase change from non-equilibrium phase to equilibrium phase.

김정한 소설어 연구 -민중성의 구현을 중심으로-

한창석 ( Chang Suk Han ) 한민족문화학회 2011 한민족문화연구 Vol.36 No.-

본고는 다음에 대략 네 가지 문제의식을 상정하고 이에 대한 답을 도출하고자 하였다. 첫째, 김정한의 소설어는 왜 창조가 아닌 복원인가? 김정한이 천착한 민중의 삶은 과거에서 현재까지 지속적인 것이었다. 허구나 전망이기 보다 증언이므로 신어나 조어가 아니라 삶의 모습을 복원하고 재현할 기존의 어휘를 소설어로 살려쓰기 위한 노력을 기울인다. 둘째, 김정한의 소설어는 왜 민중어인가? 민중의 삶을 증언하는 것은 민중의 언어로 이루어져야 한다. 아울러, 민중의 삶을 생동감 있게 증언하기 위해서는 추상어가 아닌 감각어, 생활어, 고유어로 이루어져야 한다. 셋째, 김정한의 소설어는 어떤 방식으로 작가의식의 구현에 기여하는가? ① 민중의 조락상(凋落相)의 증언; 빈궁어의 전경화 ② 민중어의 갈래; 속담과 관용어/한자성어/고유어/감각어/종교어 ③ 민중과 반(反)민중의 이분법; 구체성과 연대성 넷째, 민중과 반(反)민중의 대립구도는 어떻게 규정되는가? 민중을 수탈하고 질곡으로 몰아넣는 계급(일제, 친일파, 지주, 부패승려, 권력층)은 반민중성을 지닌다. 그런데 김정한 소설에는 반(反)민중의 역할을 수행하는 인물군의 경우에도 계급적으로는 민중의 일원인 경우가 나타난다. 따라서 반민중적 인물은 지위나 신분이 아닌 역할에 따라 판별해야 할 것이다. This manuscript is about to come up the following four kinds of the consciousness of question and obtain the answer for that. 1. What Kim chung han`s novel language is called not creation but restoration for? The populace life that Kim chung han has scrutinized is continuous up to the present time from the past. As it is a testimony to a fabrication or a prospect. The existing language reappearing and restoring their original looks rather than the need for new vocabulary to be selected as the novel language. 2. Why is Kim chung han`s novel language called as the populace language? Testifying the populace language. In addition, to testify the populace life actively. It has to be established not as an abstract language but a sensual language, a living language and their own language. 3.What`s split for language inquire into Kim chung han`s writer`s consciousness? This manuscript describe it separately as follows ① The testimony of a populace`s withering situation: The aspect of poor language. ② The restoration of a populace`s language: a proverb and idiom/idiom/chinese proverb/a existing language/a sensual language/religion language. ③ The bisect method between the populace and anti- the populace: the confrontation expression on a person and the situation. 4. Can the composition of confrontation between the populace and anti-the populace be shown effectively or pertinently? the concept language of the anti-the populace should be careful to adapt generally in the range and the standard of using, because in case of the persons performing the role of the anti-populace in work, the birth might be belonged to the members of the populace. accordingly, It is reasonable to get through the composition of confrontation with the bisect method of the populace under the key point of the role of an exploiter and a person deprived.

기계적 성질을 향상시킨 플라스틱 금형재료에 대한 평가

한창석(Chang-Suk Han),Sung-Yooun Jin 호서대학교 공업기술연구소 2020 공업기술연구 논문집 Vol.39 No.1

수요가 급증하는 엔지니어링 플라스틱 성형에 대한 금형부식 문제, 고속절삭에 의한 금형 가공 능률 향상 등 플라스틱 금형재료에 대하여 고객이 직면하고 있는 실용적인 특성평가를 통해 새로운 금형재료 및 그에 따른 적합한 사용법을 제안한다. 수지의 종류에 따라 열처리강인 13Cr계 스테인리스강뿐만 아니라 Cr포함 (4%) 40HRC의 예비열처리 석출경화강에서도 금형부식 문제를 완화할 수 있다. Cr포함 석출경화강은 일반적인 석출경화강에 비해 절삭온도가 낮기 때문에 고속절삭에서도 belag가 안정하게 공구표면에 부착, 퇴적하기 때문에 안정된 가공이 가능하다. We propose a new mold material and its proper usage through the practical characteristics evaluation that customers face with plastic mold materials, such as mold corrosion problems for engineering plastic molding, which has rapidly increased demand, and improvement of mold processing efficiency by high speed cutting. Depending on the type of resin, it is possible to alleviate the problem of mold corrosion not only in 13Cr stainless steel, which is heat-treated steel, but also in preheat-treated precipitation hardened steel containing Cr (4%) 40HRC. Precipitation hardening steel with Cr has lower cutting temperature than general precipitation hardening steel, so stable processing is possible because the belag adheres and deposits on the tool surface stably even at high speed cutting.

단면이 규칙적으로 변하는 미세유체 채널을 이용한 유전영동 기반의 박테리아 분리 장치에 대한 3D 시뮬레이션

한창호(Chang-Ho Han),김다민(Da Min Kim),송중현(Joong Hyun Song),정희원(Hee Won Chung),허진욱(Jin Uk Heo),장재성(Jaesung Jang) 대한기계학회 2014 대한기계학회 춘추학술대회 Vol.2014 No.11

Dielectrophoresis is one of the most effective technologies for separating a species of particle or cell from a heterogeneous bioparticle mixture in a microfluidic channel. If the frequency of an applied AC voltage is tuned properly, targeted particles can be concentrated in the device while the others thrown away due to the opposite direction of the applied dielectrophoretic forces between them. In this study, a 2D planar microelectrode pattern is located on the bottom, and the targeted bacteria are forced to move downward periodically due to the changing cross-sectional areas, thereby the bacteria concentrated on the electrodes. We conducted a 3D simulation of particle tracing with respect to the flow rate, and the applied peak-to-peak voltage for the calculation of particle collection efficiencies of the bacteria in the device, and we compared with those of the conventional microseparator.

On-site EEWS 구축을 위한 딥러닝 기반 지진감지 모델 개발

임종성 ( Lim Jongseong ),유정호 ( Ryu Jeongho ),송길태 ( Song Giltae ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.25 No.2

2016년, 17년 경주·포항 지진이후 정부는 지진발생 현장 중심의 On-Site 경보 기법 연구를 비롯한 총 13개의 지진방재 종합계획 세부과제를 수립하였다. On-site 지진조기경보(EEWS)의 구축을 위해서는 지진과 생활 소음(ambient vibration, Noise)의 효과적 구분뿐만 아니라 기존 시스템보다 더 신속한 P/S파 위상 판별이 가능한 알고리즘이 필요하다. 그러나 현존하는 지진 신호 검출 딥러닝 모델은 실시간성을 고려하기보다 분석과 연구의 목적이 크다. 또, 모델의 크기가 크기 때문에 소형기기에 탑재가 어려워 신호를 전달하기에 그치며, 또 다른 시스템에서 추론하는 무거운 시스템이 구축되어야 하는 실정이다. 본 논문에서는 경량화된 모델을 설계하여 실시간성 지진 탐지모델을 개발했다.

턱뼈가지의 골절로 인한 내상악동맥의 가성동맥류 1례

한창덕 ( Chang Dok Han ),김영효 ( Young Hyo Kim ),김규성 ( Kyu Sung Kim ),최호석 ( Ho Seok Choi ) 대한외상학회 2012 大韓外傷學會誌 Vol.25 No.1

Traumatic pseudoaneurysms in the head and neck region are very rare. Particularyly, pseudoaneurysms of the internal maxillary artery are known to be very rare. The authors report a 20-year old male who was diagnosed as having a pseudoaneurysm of the internal maxillary artery. The cause was assumed to be a mandible ramus fracture. When he visited our emergency room, we did not consider a pseudoaneurysm because of his other life-threatening conditions. Fortunately, he re-visited our hosipital before the aneurysm ruptured. He was diagnosed with angiography and was treated by using embolization with glue. The rupture of the pseudoaneurysm could have caused a life-threatening hemorrhage. (J Korean Soc Traumatol 2012;25:32-35)

고배속 및 고밀도 광 픽업 구동기를 위한 설계 변수의 고찰

한창수(Chang Soo Han),김수현(Soo Hyun Kim) 한국정밀공학회 2000 한국정밀공학회 학술발표대회 논문집 Vol.2000 No.5월