Numerical Analysis of Radio‑Frequency Inductively Coupled Plasma Spheroidization of Titanium Metal Powder Under Single Particle and Dense Loading Conditions

Jun‑Seok Nam,Eonbyeong Park,Jun‑Ho Seo 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.4

In order to allow more practical prediction of RF (radio-frequency)–ICP (inductively coupled plasma) spheroidizationresults of titanium metal powder, numerical analyses under single particle and dense loading conditions were carried outand the results were compared. First, both of the numerical results for Ar inductively coupled plasma with the power levelof 30 kW revealed that the injected particles can experience not only spheroidization by melting, but also size reduction byevaporation. In addition, this size reduction was found to strongly depend on the initial sizes of the injected particles, due tothe relatively short heating time. For example, the 100 μm Ti particles were computed to hardly experience size reduction byevaporation regardless of feeding rates. However, relatively small Ti particles < 100 μm can be rapidly heated up to boilingpoints during the short flight of plasma, resulting in the size reduction by the surface evaporation. In particular, numericalresults under dense loading condition showed that the final sizes of these small Ti particles can be changed depending onthe feeding rate. For example, a single 60 μm Ti particle was calculated to be a 51 μm spherical Ti particle due to the excessiveheating. However, with the increase of feeding rate up to 1.0 kg/h, the final sizes of the as-treated Ti powder couldbe improved to 55 μm due to the plasma temperatures decreasing through complicated plasma–particle interactions. Bypredicting the relationships between the feeding rates and the initial diameters of Ti powders at a given plasma power level,numerical modellings under single particle and dense loading conditions can help in optimizing the RF–ICP spheroidizationprocess of titanium metal powder.

배가스 폐열회수를 위한 히트파이프 적용성 검토

전용두,박기호,고석보 公州大學校 工學硏究院 生産技術硏究所 2005 論文集 Vol.13 No.-

A Series of experiments are performed to investigate the heat transfer characteristics of sintered metal wick heat pipe especially focusing on the operational limit of maximum allowable thermal loads and the effect of inclination slope. Tested heat pipes are composed of copper tube with pure water as a working fluid. The outer diameter of the heat pipe is 6mm and the total length is 300mm, which covers the evaporator section(50mm), adiabatic section(100mm) and condenser section(150mm). respectively. Experimental data of wall temperature distribution along the axial locations are obtained to evaluate the performance of the heat pipe at different slopes. Each test is performed by changing the input thermal loads ranging from 5W to 30W.

육우 비선호 부위를 활용한 육우햄의 품질특성

이주호, 최정석, 정준영, 최양일 忠北大學校 農業科學硏究所 2012 農業科學硏究 Vol.28 No.3

This study was undertaken to compare the quality characteristics of dairy beef ham. Dairy beef hams were manufactured using non-preferred portion (top round). 5 treatments were prepared: T1(beef 50% + pork emulsion 50%), T2(beef 65%emulsion 35%), T3(beef 80%emulsion 20%), T4(beef 90%emulsion 10%), T5(beef 100%emulsion 0%). In chemical composition, dairy beef content increases, moisture content was increased, fat content was decreased. In the meat quality characteristics, T5 showed higher (p<0.05) water holding capacity value than the others. Dairy beef content increases, product loss and cooking loss were decreased. In hunter color, dairy beef content increases, redness was increased. In texture profile analysis, T4 and T5 were significantly higher than the others. As a result, dairy beef ham with 80~90% dairy beef and 10~20% pork emulsion has low fat content, high product yield and superior texture profile, which could be developed as a dairy beef hams using non-preferred portion.

공조시스템을 적용한 석실 고분내 온ㆍ습도 분포

전용두,이금배,박진양,고석보,전희호 公州大學校 工學硏究院 生産技術硏究所 2005 論文集 Vol.13 No.-

Although the importance of good conservation of historic sites including ancient royal tombs is well aware, still not much attention has been paid for the facilities and systems to preserve those historic sites, which includes precious artifacts as wall paints and carved works, etc. Even the general understanding about the environment of the underground space of tombs is not satisfactory. In Korea, researchers have recently begun addressing the above issue and are making efforts to develop suitable HVAC(heating, ventilating and air-conditioning) systems for conservation of tombs. An experimental investigation was carried out to study the behavior of the HVAC system installed for a tomb. This tomb resembles in size and shape the original stone built tomb of Baek-je Dynasty, which dates back to 6th Century in southwest part of Korean peninsula. In this study, an HVAC system for a tomb(D×W×H=1.3m×3.0m×1.2m) was installed to maintain sui표 indoor conditions for conservation of tomb. The temperature and humidity inside the tomb were measured different of the setting. Finally, performance of the HVAC system is presented and discussed.

電子産業의 實態分析 및 競爭力 提高戰略

鄭俊秀,尹英得,方鎬烈,金基錫,金正敎 釜山大學校 經營 經濟 硏究所 1990 經營 經濟 硏究 Vol.9 No.1

최근 6년간 연세의료원에서 경험한 한국인 안면골 골절에 대한 임상적 연구

권준호,이충국,이의웅,민우석,윤중호,박형식 大韓顎顔面成形外科學會 1989 Maxillofacial Plastic Reconstructive Surgery Vol.11 No.1

This is a series of continuing research on facial bone fractures of Koreans worked by Dept. of Oral and Maxillofacial surgery, Dental College of Yonsei University, Seoul, Korea, since 1972. The study was based on a series of 630 patients with facial bone fractures treated as in patient at Yonsei Medical Center, Yonsei University, during the period of Jan. 1982 through Dec, 1987. The results obtained are as follows: 1. The ratio of Men to Women was 4.3 : 1, and admissions for facial bone fractures have been increased year after 1984. 2. The age frequency was highest in the third decade(38.3%). and fourth, second, fifth decade in orders. 3. The traffic accident was the most frequent cause of facial bone fractures(51.3%). 4. The most common location of facial bone fractures was the Mandible(35.3%), and Zygoma complex(29.8%), Nasal bone(15.0%), Maxilla(11.0%) were next in order of frequency. 5. In 291 patients of Mandible fractures, 226(77.7%) had fractures only in Mandible and 65(22.3%) had another facial bone fractures. The most frequent fracture site of mandible was the Symphysis(43.0%) and Angle(22.4%), and Simple fracture was the most frequent in type of fracture(66.9%). Intermaxillarty fixatin & Open reduction was major method of treatment(36.9%). 6. In 394 patients of Midface fractures 323(82.0%) had fractures only in Midface and 71(18.0%) had another facial bone fractures. The most frequent site of Midface fractures was zygoma complex & zygomatic arch(42.7%), and Simple fracture was the most common type of fractures. Observation(Maxilla :44.2%, Zygoma :51.0%) and Open Reduction(Maxilla :20.0%. Zygoma :23.5%) were the major method of treatment. 7. The frequency of Nasal bone fracture was about 1/5 of Midface fractures, and Closed Reduction(42.2%) was the major method of treatment. 8. The complication was reported in only 16 patients, and Malunion was the major complication. 9. Head(44.4%), Lower extrimities(14.5%) and Eye(12.3%) were injured commonly with facial bone fractures. 10. The elapsed time from injury to hospital was within 24 hours in 73.8% of patients, however 15.5% of patients arrived the hospital 72 hours after injury.

거푸집공사 위험성 평가에 관한 연구

고성석,오준호 한국산업안전학회 2002 한국안전학회지 Vol.17 No.3

The object of risk assesment is to prevent the accident from arising. The main reason for risk assesment of construction work is to determine priority order of improvement plan about risky work. Formwork is a complicated process that determines the total duration of apartment construction, and occupies 10~15% of total construction expense, and 17% of serious accidents occur during formwork. So, formwork occupies very importment roles in work sites, economical efficiency and safety. We need to identify the work type with a high risk of accidents, and to establish suitable safety counterplan and implement intensive safety management.

정신재활 치료가 정신분열병 환자의 재발율, 입원횟수, 입원일수 그리고 치료 경비에 미치는 효과 : 2년 추적조사 연구

조진석,공지현,김진원,심경순,하준선,김철권,강동호,장정희,변원탄 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.5

목 적 : 사회기술훈련, 환자교육, 가족교육, 집단치료, 예술치료, 작업치료와 같은 포괄적인 정신재활 치료를 약물치료와 병행할 경우 약물치료만 시행할 때에 비해 정신분열병 환자의 재발율, 입원횟수, 입원일수, 직접 치료경비 등에 어떤 효과가 있는 지를 알아보기 위함이다. 연구방법 : 1993년 9월부터 1995년 2월까지 양산 신경정신병원의 폐쇄병동에서 퇴원한 20∼35세 사이의 정신분열병 환자 173명을 대상으로 46명에게는 6개월동안 정신재활 치료를 시행하였고 127명에게는 통상적인 외래치료만 시행한 후 연구시작 시점을 포함하여 2년동안 양군에 속한 환자들을 대상으로 재발율, 입원횟수, 입원일수, 직접 치료경비 등을 1년 단위로 추적 조사하였으며, 연구시작 시점을 기준으로 전과 후의 매년 평균 입원횟수, 입원일수, 직접 치료경비도 서로 비교하였다. 결 과 : 정신재활 치료를 약물치료와 병행할 경우 약물치료만 시행할 때에 비해 재발율, 입원횟수, 입원일수, 직접 치료비용이 현저히 감소되었다. 그리고 정신재활 치료를 받은 군에서는 치료 전에 비해 치료 후에 재발율, 입원횟수, 입원일수, 직접 치료비용이 유의하게 감소하였지만 통상적인 외래치료만 받은 군에서는 치료 전과 후간에 유의한 변화를 보이지 않았다. 결 론 : 정신분열병 환자들에게 정신재활 치료를 약물치료와 병행할 경우 약물치료만 시행할 때에 비해 환자의 임상적 경과를 호전시킬 뿐 아니라 가족의 경제적 부담도 줄일 수 있다. Objective : We evaluated the clinical efficacy of a comprehensive psychiatric rehabilitation of schizophrenia, including family psychoeducation, patient education, social skills training, group psychotherapy, art therapy, and occupational therapy. Method : From September 1993 to February 1995, 173 chronic schizophrenics who met DSM-IV criteria and were discharged from a locked ward were assigned into the psychiatric rehabilitation service group(psychiatric rehabilitation group, n=46) or the customary out-patient service group(out-patient group, n=127) prospectively, but not randomly. Assignment was based on preferences of patients and their relatives, Each subject included in the psychiatric rehabilitation group received twice weekly patient education, social skills training, family psychoeducation, group psychotherapy, art therapy, occupational therapy and maintenance chemotherapy during a 6-month period. Those in the out-patient group received individual supportive psychotherapy and maintenance chemotherapy according to their clinical needs for 10-20 minutes once per week. After entry into the study, all subjects were assessed for the number of readmission, days of hospitalization, and the direct treatment costs through the first and second year of follow-ups. These outcome variables were also compared pre-and post-2 years at the time point of entry into the study. Aftercare chemotherapy on a weekly to monthly basis continued for the remainder of the two year follow-up period. Results : With regard to the mean number of hospital admissions per year, the mean days of hospitalization per year, and the direct treatment costs per year, the psychiatric rehabilitation group had significantly decreased all clinical outcomes 2 years after compared with before receiving psychiatric rehabilitation. But there were no significant differences in the all clinical outcomes between before and after study intake in the out-patient group. For the number of relapse regardless of drug compliance, 4 patients(9%) during first year and 14 patients(30%) during second year were relapsed in the 46 subjects of the psychiatric rehabilitation group. In contrast, 75 patients(59%) during first year and 90 patients (71%) during second year relapsed in the out-patient group. When considering the effect of drug noncompliance to relapse, 4(9%) and 14 patients(30%) were relapsed while on medication respectively during the first and second year in the 46 of the psychiatric rehabilitation group, vs. 27(34%) of 79 patients on medication during the first year and 31(46%) of 68 patients on medication during the second year were relapsed in the out-patient group. Conclusions : These results indicate that the comprehensive psychiatric rehabilitation can be useful therapeutic intervention both to improve the clinical outcomes of schizophrenic patients and to reduce the economical burden of their relatives.

고압전류 감전자에게서 나타난 말초신경병증 증례보고

손준석,김영욱,채창호,민경범,이철호 대한산업의학회 2006 대한직업환경의학회지 Vol.18 No.4

Background: With increasing industrial development, opportunities are growing to contact electricity in the workplace or home. Therefore, the risk of electrical accident has been increased gradually. In general, electrical injuries involve the extremities and result in amputation or severe disability of limbs. Delayed spinal cord injury and peripheral neuropathies following electrical accidents are extremely rare. Case report: A 32-year-old man with 10 years working experience at a CRT-monitor manufacturer with repetitive exposures to high voltage current visited our hosipital. He complained of left leg weakness and atrophy, and intermittent pain. The symptoms were progressive. Other symptoms occurred such as nocturia, hesitancy, and weak urinary stream. We examined the patient and conducted EMG, L-spine MRI, neurometer test, isokinetic strength test, and physical examination. The results showed neural injuries due to anterior horn lesions or compression of the left femoral nerve pathway, with a consequent diagnosis of neurogenic bladder.

마이크로스트립 지연선 여파기에 관한 연구

윤준식,박규호,윤철상,박준석,안달 호서대학교 반도체제조장비국산화연구센터 2000 학술대회 자료집 Vol.2000 No.1

일반적으로 LPA에서는 위상을 조정하기 위해 매우 긴 지연선을 필요로 한다. 지연성능은 고전력이나 저전력 모두에서 임의의 길이의 동축선로를 여러번의 과정을 거쳐 적용해봄으로써 구현된다. 그러나 동축선로형 지연선은 부피나 높은 삽입손실등의 제약이 많이 따른다. 본 논문에서는 마이크로스트립 형태의 지연선 대역통과 여파기를 설계하였고, 실험결과는 지연선여파기가 동축선로를 대신하여 LPA 시스템에 적용이 가능함을 보였다.