나노/마이크로 바이모달 피드스탁의 유변학적 물성에 대한 연구

노재범(Jaebum Noh),오주원(Joo Won Oh),박재만(Jae Man Park),박성진(Seong Jin Park) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

Powder injection molding technique is an appropriate manufacturing process for 3-dimensional complex products. Nano powder was introduced in the process for microfabrication, but it increases the process difficulty and process cost. Nano/micro bimodal powder can be a solution to minimize the drawback of nano powder. Some research groups dealt with nano/micro bimodal powder injection molding process. However, most of their works only focused on the properties of sintered samples despite the importance of the injection molding step. Thus, in this study, the rheological property of nano/micro bimodal feedstocks was investigated with capillary rheometer. Flow index and flow activation energy were calculated from the result with the Arrhenius and powder law model. Moldability index was also obtained for each feedstock, and 12 % nano bimodal feedstock was regarded as the most desirable feedstock for injection molding process.

초고온가스로 노심 열유체 코드 개발 현황 및 과제

탁남일(Nam-il Tak),김민환(Min-Hwan Kim),임홍식(Hong Sik Lim),노재만(Jae Man Noh) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

축산물 및 가공 : 산란계 주령과 계란 난각 형태이상 정도가 내부품질에 미치는 영향

이재익 ( Jae Ik Lee ),이현정 ( Hyun Jung Lee ),김희수 ( Heui Soo Kim ),조철훈 ( Cheor Un Jo ),김선만 ( Sun Man Kim ),노재중 ( Jae Jung Noh ) 한국동물자원과학회 ( 구 한국축산학회 ) 2012 한국축산학회지 Vol.54 No.1

본 연구는 산란계의 주령 및 난각의 형태이상 및 이상 정도가 내부품질에 미치는 영향을 조사하기 위해 실시되었다. 동일 주령의 산란계 2계군에서 56주령부터 62주령 사이에 산란한 계란 21,000개 중 각 주별 1,000개를 무작위 추출하여 축산물품질평가사가 정상란과 형태 이상란을 구분하였다. 각각의 출현율과 할란검사를 실시하여 내부품질을 조사한 결과 전체적으로 정상란은 81.22%, 이상란은 18.78%의 출현율을 보였다. 주령의 증가에 따른 이상란의 출현율은 유의적인 차이를 보이지 않았으며(p>0.05), Haugh unit은 60주령이 56주령에 비해 높게 나타났으며 그 외에는 차이가 없었다. 동일 주령대를 비교했을 경우 난백고와 Haugh unit은 형태 이상란이 낮고 또한 이상의 정도가 심한 경우 더 낮게 측정되는 결과를 보였다(p<0.05). 특히 이상란 중 기형란의 난고와 Haugh unit이 현저하게 낮은 결과를 보여 이상란 중에서도 기형란이 내부품질이 가장 낮게 판명되었다. 결과를 종합해 보면 56~62주령 산란계로부터 생산된 계란의 외형적 이상은 내부품질의 저하와 밀접하게 상관한다고 볼 수 있으며, 현 계란 등급판정 체계에서 외관판정은 신선도 평가에 근거가 될 수 있을 것으로 보인다. This study was carried out to investigate the effects of age of laying hens and grade of shell abnormality on internal egg quality. At each week, 1,000 eggs were randomly selected from 21,000 eggs laid by Hy-Line hens(100,000 birds) aged from 56 to 62 wk. The samples were divided into normal and externally abnormal eggs by an official egg grader. Then, egg quality including egg weight, egg white height, Haugh unit and yolk color was evaluated from each normal and abnormal eggs. The production rate of externally normal and abnormal eggs was 81.22 and 18.78%, respectively. No difference found in the production rate by the increase of hen`s age, but Haugh unit of eggs from hens of 60-wk-old was higher(p<0.05) than that of 56-wk-old. When the same age groups were compared, egg white height and Haugh unit were lower in eggs which were externally abnormal. When the grade of abnormality increased, egg white height and Haugh unit were decreased further (p<0.05). Among the externally abnormal eggs, malformation showed the lowest Haugh unit. In conclusion, the shell abnormality of eggs laid by hens aged 56 to 62 wk was closely related with internal egg quality. Therefore, the grading external egg quality in the present egg grading system is directly related with the internal egg freshness.

3배체 수박 재식 거리에 따른 품질 변화

김정만(Jeong Man Kim),김태복(Tae Bok Kim),성문호(Mun Ho Seong),노재종(Jae Jong Noh),임정현(Jeong Hyeon Lim),정기태(Gi Tae Jung) 한국원예학회 2013 한국원예학회 학술발표요지 Vol.2013 No.5

IV route에 따른 Neck CTA 영상의 적정성에 관한 고찰

정명진(Myung Jin Jung),전재두(Jae Doo Jeon),정지훈(Ji Hoon Jung),박상록(Sang lok Park),전진만(Jin Man Jeon),노지숙(Ji Sook Noh) 대한CT영상기술학회 2012 대한CT영상기술학회지 Vol.14 No.2

목적 본 연구에서는 Ⅳ route에 따라 Neck CTA검사 시 Ⅳ route 확보에 대한 문제점의 해결과 높은 진단영상 획득을 위한 프로토콜을 제시하고자 한다. 대상 및 방법 2011년도 12월부터 2012년 2월까지 광주광역시 C 대학병원에 Neck CTA 검사를 위해 내원한 환자 중에서 영상판독결과 질환이 없는 환자를 대상으로 하였고, Ⅳ route를 상지혈관에 확보한 환자 23명과 하지혈관에 확보한 환자 30명을 연구대상으로 조사하였다. Curved MPR 영상에서 ICA부위에 HU값을 측정하였고, 측정한 HU값의 측정오류를 최소화하기 위하여 한 연구자가 근위부에서 원위부까지 각각 3회씩 측정하여, 이들 HU값의 평균과 표준편차를 구했다. 평가방법은 영상의학과 전문의 2명, 방사선사 3명에 의해 평가하였으며, 조영제에 의한 인공물이 혈관에 미치는 정도와 조영증강 정도에 따라 최고점수 5점을 부여하였고, 나머지는 차례로 1점 단위로 하위점수를 부여하여 평가하였다. 통계분석은 독립표본 t-test 검정을 시행하였고, p<0.05인 경우에 통계학적으로 유의한 것으로 보았다. 결과 상지에 혈관을 확보한 군의 HU 평균값은 463.36±94.77, 하지에 혈관을 확보한 군의 HU 평균값은 372.98±74.32로 나타났고, 영상 평가한 결과 상지에 혈관을 확보한 환자의 검사영상에서 4.14±0.81점, 하지에 혈관을 확보한 환자의 검사영상에서 4.18±0.65점으로 나타났다. HU값과 영상평가에 따른 독립표본 t-test 검정을 한 결과 통계적으로 유의하였다 (p<0.05). 결론 Neck CTA 검사 시 상지에 혈관을 확보 시에도 Dual injector를 이용한 조영제와 생리식염수를 투여하고 검사방향을 머리에서 발쪽으로 높은 피치로 검사함으로써, 견측 부위에서의 조영제로 인한 인공물 발생을 줄일 수 있어 진단적으로 양질의 영상을 얻을 수 있었다. I. Purpose This study aims to present a protocol to attain solutions to problems involving Ⅳ route in Neck CTA and acquire diagnostic images according to Ⅳ routes. II. Meterial and Methods For the purpose, this study analysed patients who came to C university hospital for Neck CTA from December 2011 to February 2012 and had no diseases as a result of image reading. The subjects were categorized in the following: 23 patients with Ⅳ route at their upper extremity and 30 ones with Ⅳ route at their lower extremity. HU values were measured at the ICA of the curved MPR images and to minimize errors in the HU values, this study measured them from the proximal to the distal three times for a subject to obtain means and standard deviations. Two radiologists and three radiological technologists participated in the evaluation, and a maximum of five points were given according to the degrees that contrast media affected blood vessels and the intensity of contrast enhancement, and sub-points were given to the rest. For a statistical analysis, a t-test was conducted and in case of p<0.05, it was suggested that it was significant. III. Result The mean HU values of the group with Ⅳ route at the upper extremity were 463.36±94.77 and those of the group with Ⅳ route at the lower extremity were 372.98±74.32. As a result of evaluating the images, the points of the former subjects were 4.14±0.81 and those of the latter subjects were 4.18±0.65. It was discovered that the results of the HU values and the t-test were statistically significant(p<0.05). IV. conclusions In the Neck CTA, to secure IV routes at the upper extremity, contrast media and saline were injected with a use of a dual injector and an examination was done from the head to the leg to decrease occurrence of artificial things due to contrast media and to attain good-quality images.

초고온가스로 모사 실험회로 설계를 위한 전산유체역학 해석

윤철(Churl Yoon),홍성덕(Sung Deok Hong),노재만(Jae Man Noh),김용완(Yong Wan Kim),장종화(Jong Hwa Chang) 대한기계학회 2010 大韓機械學會論文集B Vol.34 No.5

한국원자력연구원에서는 초고온가스로를 모사할 수 있는 중형 헬륨 회로를 건설 중에 있다. 이 실험 헬륨 회로에서 두 개의 전기 가열기가 헬륨 유체를 1 ~ 9 ㎫ 의 압력 하에서 950℃ 까지 가열하게 된다. 이 실험 헬륨 회로의 설계 사양을 최적화하기 위하여, 본 연구에서는 두 개의 가열기 중 하류에 위치한 고온 헬륨가열기 안의 복합열전달 현상을 전산유체역학으로 해석하였다. 해석 결과에서 헬륨 가열기 내 최대 온도는 허용 한계를 넘지 않았고, 이로써 선정된 기하구조의 열적 특성은 설계요건을 만족함이 확인되었다. A medium-scale helium loop that can simulate a VHTR (very-high-temperature reactor) is now under construction at the Korea Atomic Energy Research Institute. The heaters of the test helium loop electrically heat helium fluid up to 950℃ at pressures of 1 to 9 ㎫. To optimize the design specifications of the experimental helium loop, the conjugate heat transfer in the high-temperature helium heater was analyzed by performing a CFD simulation. The analysis results indicate that the maximum temperature does not exceed the allowable limit. It is confirmed that the thermal characteristics of the loop with the given geometry satisfy the design requirements.

수박 재배양식이 품질 및 수량에 미치는 영향

성문호(Munho Seong),임정현(Jeong Hyeon Lim),노재종(Jae Jong Noh),김태복(Tae Bok Kim),정기태(Ki Tae Jeong),김정만(Jeong Man Kim) 한국원예학회 2013 한국원예학회 학술발표요지 Vol.2013 No.10

Thermal-fluidic Effects of the Spacers in an Experimental Helium Loop for VHTR Simulation

윤철(Churl Yoon),홍성덕(Sung Deok Hong),노재만(Jae Man Noh),김용완(Yong Wan Kim),장종화(Jong Hwa Chang) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

MDCT의 다양한 알고리즘과 관상동맥내 삽입된 스텐트 내경측정의 영향

정명진(Myung Jin Jung),전재두(Jae Doo Jeon),노지숙(Ji Sook Noh),전진만(Jin Man Jeon),김동훈(Dong Hun Kim) 대한CT영상기술학회 2008 대한CT영상기술학회지 Vol.10 No.1

Purpose To analyze diameter of stem within phantom and coronary artery and to recognize various algorithm effects that make blooming artifact commonly. Materials and Methods Phantom model was manufactured as follows: stem located in center of thin plastic pipe was situated in glass bottle and mixed saline and contrast (10:1) was filled in bottle. Total 80 patients (man : woman = 53 : 27, mean age = 60.8 years old) who undergo percutaneous coronary intervention (stenting) were included in this study. Coronary CT angiography was performed with the use of a 16- slice MDCT scanner with a 0.42-s rotation time (Sensation 16, Siemens, Erlangen, Germany) and a 64-slice MDCT scanner with a 0.42-s rotation time (Brilliance 64, Philips Medical Systems, Best, The Netherlands) with retrospective ECG gating.A standard scanning protocols were applied. Six radiological technicians measured internal diameter of stem within phantom and coronary artery respectively. As much as possible, we exclude artifacts including blooming artifact. For evaluation of images, window width and window center were used as 900 ± 100 and 400 ± 100 each. Results In phantom model, average inside diameter measured by each algorithms appeared most greatly as 2.35 mm (B50f in S company) and 2.53 mm (XCB in P company) respectively. In patients, in stent resolution processed by XCC was scored as 7.67 (highest) and others (XCA, XCB, XCD) got similar scores. Conclusion B40f (S company, 16 slice MDCT) and XCC (P company, 64 slice MDCT) are appropriate algorithms for evaluating internal patency of stent within coronary artery.

초고온가스로 모사 실험회로 설계를 위한 전산유체역학 해석

윤철(Churl Yoon),홍성덕(Sung Deok Hong),노재만(Jae Man Noh),김용완(Yong Wan Kim),장종화(Jong Hwa Chang) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

A medium scale Helium loop that can simulate a VHTR(Very High Temperature Reactor) is now under construction in Korea Atomic Energy Research Institute. The heater of the test Helium loop electrically heats up the Helium fluid up to 950℃ at the pressure of 1 ~ 9㎫. To optimize design specification of the experimental Helium loop, conjugate heat transfer in the high-temperature Helium heater was analyzed by CFD simulation. From the analysis results, the maximum temperature does not exceed the allowable limit. It is confirmed that thermal characteristics of the given geometry well meet the design requirements.