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.

자동차차체 및 부품제조업 산업장의 작업환경실태에 관한 조사 연구

서준호,문덕환,김정호,이채관,황용식,손병철,김대환,이창희,김휘동,이채언 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.5

Objectives: For the purpose of preparing the fundamental data and control the working environment and assessing the status of working environmental in manufacturing industry of bodies for motor car and of parts. Methods and Materials: Accessories for motor car and its engines the auther measured the noise level, concentration of dust, heavymetals, organic solvents, chemicals to 99 industries(24 working processes) form Feb. 2000 to Oec. 2000. Results: The results were as follows : 1. Mean noise level cutting, grinding, pressing, foundries and shot-blast was exceeded to threshold limit value(TLV) of noise. 2. Mean concentration of total dust was not exceeded to TLV. 3. Mean concentration of Mn in welding process and Pb in drying, welding, fabricating, rolling was exceeded to TLV. 4. Mean concentration for chemicals and organic solvents were not exceeded to TLV. 5. Mean concentration of dust and heavymetals were statistical significant difference between with local ventilation system and without local ventilation system. Conclusion: Above results, author suggest to prepare more passively control to working environment where exceeded the TLV.

양극성 장애의 우세삽화와 임상양상 간의 연관성 : 예비연구

서호준,우영섭,채정호,전태연,김광수,박원명 大韓神經精神醫學會 2007 신경정신의학 Vol.46 No.5

Objective : This study was performed to fmd clinical implications ofdistinctive pattems in bipolar patients with predominance of depressive episodes or manic episodes and to find possibilities to predict predominant episodes in bipolar disorder. Methods : The recmitment period was between 2002 and 2004, among inpatients who had received psychiatric treatment for bipolar disorder. The data about the number and the polarity of the past episodes were collected through medical records, and Sub-jects were divided into depressive or manic episode predominant groups. The two groups were compared regarding Sociodemo-graphic and clinical variables. Results : 74 patients met the inclusion criteria during the study period. 21 subjects were classified as depressive episode Pre-dominant group (depressive episode group), and 53 subjects as manic episode predominant group (manic episode group). There were no differences in sociodemographic data, the number of total episodes and hypomanic episodes, and onset age. However, 90.5% (n=19) subjects of depressive episode group showed depressive episode as first episode, and 88.7% (n=47) of manicepisode group experienced manic episode as first episode (χ²=42.13, df=1, P<0.00l). Psychotic symptomswere significantly more prominent in the manic episode group (χ²=6.85, df=1, P=0.009), and the number ofsubjects who had suicide attempt experience was higher in the depressive episode group (χ²=7.39, df=1, P=0.007). In the comparison of highest GAF scores during the past year, significant difference was found between the two group (p=0.046), as the mean scores of depressive epi-sode group was 68.337±7.47 and manic episode groupwas 71.51±5.42. Conclusion : The results ofthis study show that there are differences in clinical features according to predominant episodes in bipolar disorder. The type of onset episode appears to be related to predominant episode in this study, and it would be a valid Pa-rameter with therapeutic implication in bipolar patients.

개에서 발생한 자궁축농증 1례

서수원,손정민,윤기영,최호정,박성준,이영원,정성목,신상태,조종기 忠南大學校 獸醫科大學 附設 動物醫科學硏究所 2006 動物醫科學硏究誌 Vol.14 No.-

A 12-year-old, female miniature pinscher dog with history of fever and vaginal discharge 3 days ago was referred to the Veterinary Medical Teaching Hospital of Chungnam National University. A diagnosis of pyometra was made by survey of abdominal radiographs and ultrasonography. The uterus appeared as convoluted and tubular appearance filled with anechoic to hypoechoic fluid. Ovariohysterectomy was the choice of cervical patency. Medical therapy for pyometra may be appropriate in bitches that were of breeding age and that were not systemically ill. The surgery was fine. After 1 week, the dog was getting better.

응급실에서 소아환자의 진정제로서 케타민(Ketamine)의 사용

서정필,박준석,황태식,장석준,김승호 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Ketamine use in emergency room has been increased. It has rapid onset of action and appropriate duration of action. It does not need endotracheal intubation and produces potent analgesia, sedation, and amnesia. The object of this study is to determine the safety and the degree of physician's satisfaction in relation to ketamine use. Materials and Methods: This is a prospective study using protocol. Pediatric trauma patients who need sedation were given IM ketamine(4 ㎎/㎏) and atropine(0.01 ㎎/㎏) in a same syringe. Monitoring of patients was done by EM residents and complications of ketamine use were recorded. Physician's satisfaction was also recorded after the procedure. Results: Intramuscular ketamine was administered 54 times, mainly for laceration repair. Physicians completed protocol for 51 of treated children. The median time for onset of sedation was 6.5±2.4 min, and duration of action was 32.4±10.8 min. Hypersalivation occurred in 9.8%(n=5); random movement 3.9%(n=2), emesis during procedure(n=1), emesis at home(n=1), and transient oxygen desaturation(n=1). All were quickly identified and treated without specific airway management and sequelae. Of 84% of physicians was satisfied with ketamine use for pediatric sedation. Conclusion: Intramuscular ketamine can be administered safely and satisfactorily in emergency room to facilitate pediatric procedures in conjunction with a defined protocol and appropriate monitoring.

폐목질을 사용한 모르터의 물성에 관한 기초적 연구

황병준,김영주,강태경,정근호,임서형,정상진 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

Recently, as the alternatives to preserve environment such as effective usage of wastes or unusable resources are drawing attentions, researches and measures for the two tasks, which are reuse of waste wood and development of eco friendly materials, are being examined and established in various fields. However, they are still insufficient. Therefore, in this study, for the efficient application of waste woods and eco-friendly effects, mortar was produced using sawdust as the waste wood and mineral material cement for combination, in order to produce inorganic boards using waste woods, which were made when sawing. This study attempted to suggest a basic material about the physical properties of mortar, which used waste woods, after examining the features of wood mixture rate, water-cement rate, congelation according to the mixture rate of the setting accelerator, specific gravity, compression intensity, and bending intensity as experiment factors.

과민성 장증후군 환자에서 베타 아드레날린 수용체 기능의 활성도와 불안 수준

강은호,이풍렬,이준행,김현서,이종철,유범희 大韓神經精神醫學會 2004 신경정신의학 Vol.43 No.1

Information Technology의 기존 관광산업에 대한 영향 및 향후 Trend에 대한 전망 : 사이버여행사 수익모델을 중심으로 Profit Model of Cyber Travel Agency

조현준,나윤중,임형순,엄서호 한국문화관광학회 2001 문화관광연구 Vol.3 No.1

IT has an influence on the travel agency as chance and threat. The purpose of this study is to find what profit model of cyber travel agency. Ernst&Young's five business profit models that are based on target audience and transaction focus is selected to evaluated existing model of cyber travel agency. Those are off-line facilitator, gateway, context provider, commerce destination, online exchange. The result of this study show that there is no specific profit model in domestic cyber and on-offline travel agencies. Just Portal cyber travel agencies abroad have a few profit model. They have online exchange model, which are various target audience and abound provide contents.

원발성 후복막 점액낭샘암종 1예

지준호,이화정,박승찬,박정철,최은정,서혜진,이원식,이정림,배병조,손경락,이경희 영남대학교 의과대학 2008 Yeungnam University Journal of Medicine Vol.25 No.2

Primary retroperitoneal mucinous cystadenocarcinoma is a very rare malignancy, and little is known concerning its Pathogenesis, optimal treatment, and prognosis. A 29-year-o1d pregnant woman (21 weeks) Presented with abdominal discomfort CA 19-9, CA 125, and CEA were normal Abdominal CT scanning revealed a 19x15x13 cm retropentoneal tumor Exploratory laparotomy and tumor excision were performed. Mucinous retropentoneal implants were removed as completely as possible Histologically, the tumor showed focal areas of capsular invasion, but free resection margins The uterus and both ovaries were normal in appearance No adjuvant therapy was pursued. Six months later, Peritoneal and bilateral ovarian metastases were discovered. Hence, we report the details of this case of primary retroperitoneal mucinous Cystadeno-carcinoma and present a review of the literature.

골수염의 진단에 있어서의 Tc-99m Hexamethylpropylene amine oxime 백혈구 스캔의 임상적 유용성

최상호,김양수,정준원,정진원,추은주,서동대,배인규,양승오,우준희,류지소 대한화학요법학회 2001 대한화학요법학회지 Vol.19 No.1

배경 : 골수염의 진단에 있어 Technetium-99m을 이용한 삼상 골스캔(Tc-99m MDP스캔)은 단순방사선 검사상 정상소견을 보이는 경우에 쓰이는 1차적 검사로 매우 높은 민감도를 보인다. 그러나 Tc-99m MDP 스캔은 골절이나, 정형외과적 삽입물, 신경병적 관절병변과 같이 뼈의 재형성이 증가되는 상황에서도 양성소견을 보여 특이도가 낮은 단점이 있다. 이러한 단점을 보완하고자 골수염의 진단에 있어 Tc-99m HMPAO 백혈구 스캔의 유용성을 알아보고자 하였다. 대상 및 방법 : 골수염이 의심되어 Tc-99m HMPAO 백혈구 스캔을 시행했던 15명의 의무기록을 후향적으로 분석하였다. 골수염의 확진은 임상관찰 소견과 배양검사 결과와 병리소견을 기준으로 하였다. 결과 : 골수염의 진단에 있어 Tc-99m HMPAO 백혈구 스캔의 민감도와 특이도는 각각 100%와 78%였고 Tc-99m HMPAO 스캔의 경우는 100%와 18%였다. 가장 흔한 원인균은 methicillin-resistant S. aureus였다. Tc-99m MDP 스캔에서 양성소견을 보였던 환자중 3명의 환자가 Tc-99m HMPAO 백혈구 스캔에서 음성 소견을 보였으며 이 환자들은 추적관찰상 골수염이 없는 것으로 확인되었다. 결론 : Tc-99m HMPAO 백혈구 스캔은 골수염의 존재를 진단하는데 있어 민감도와 특이도가 높으며, 특히 뼈의 재형성이 증가되어 Tc-99m MDP 스캔의 특이도가 낮게 나타나는 상황에서 유용하리라 사료된다. Background Three phase bone scintigraphy, performed with technetium-labeled diphosphonates (Tc-99m MDP scan), is the very sensitive radionuclide procedure of choice for diagnosing osteomyelitis. But, Tc-99m MDP scan is less specific when bone remodeling is increased. To overcome this limitation, we evaluated the diagnostic value of technetium-99m hexamethylpropyleneamine oxime (HMPAO) labeled leukocyte scan in osteomyelitis. Methods : We retrospectively reviewed 15 patients with suspected osteomyelitis who performed Tc-99m HMPAO labeled leukocyte scan. The diagnosis of osteomyelitis was based on clinical course and bacterial culture, and pathologic findings. Results The sensitivity and specificity of Tc-99m HMPAO leukocyte scan was 100% and 78%, and those of Tc-99m MDP scan was 100% and 18%, respectively. The most common organism was Methicilein-Resistant S. aureus. Among the patients that showed persistent accumulation on Tc-99m MDP scan, three patients showed no uptake on Tc-99m HMPAO leukocyte scan and these patients were confirmed that had no osteomyelitis. Conclusion : Tc-99m HMPAO leukocyte scan is a useful test for determining the presence or absence of osteomyelitis, especially under condition that bone remodelin is increased.