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.

당(唐) 태종대(太宗代) 반위(反胃) 치료법의 개발과 백제(百濟) 의자왕(義慈王)의 질병

박준형 ( Park Jun-hyoung ),서영교 ( Seo Young-kyo ) 대구사학회 2021 대구사학 Vol.142 No.-

唐은 기본적으로 隋의 의료체계를 수용하면서도 醫術世家의 秘傳에 의해 분산ㆍ난립된 醫術의 독점을 국가의 의료체계라는 公的 영역으로 흡수하고자 하였다. 나아가 당은 그 의술을 민간에 유포함으로써 점차 의술세가의 독점적 입지를 좁혀 나갔다. 공익을 위한 의술 공개는 당 왕조의 존재 이유를 백성들에게 가장 효율적으로 각인시키는 방법의 하나였고, 이는 초기 왕조의 안정화에 기여하였다. 당 태종대 당나귀오줌을 이용한 반위 치료법 개발은 이러한 의료정책의 결실이었다. 蔣ㆍ許ㆍ巢氏 醫官들의 연구를 통해 이루어낸 새로운 치료 법은 즉위 초반부터 숙환이 있던 의자왕에게도 주목받았다. 644년 초 의자왕은 당에 파견된 사신을 통해 의사를 알아보았고, 그해 말 입당한 태자 夫餘康信이 당 태종에게 蔣元昌의 왕진을 요청했다. 당시 장원창은 益州道로 파견나가 있었기 때문에 당 태종은 그를 백제에 보낼 수 없었다. 결과적으로 태자를 보내 백제의 신라공격에 대한 입장을 해명하고 신라를 침공하지 않겠다고 약속했던 의자왕이 645년에 신라를 공격했다. 그해 고구려와 전쟁을 시작한 당 태종은 신라를 이용하여 고구려의 병력을 남쪽으로 분산시키고자 했던 의도가 무산되었다. 현재 학계에서는 백제의 신라 공격 이유를 명확하게 설명하지 못하고 있다. 645년 백제의 신라 공격으로 백제와 당의 관계가 악화되었다. 이는 신라가 대당외교에서 성공할 수 있는 여건을 만들어 주었다. 이런 점에서 645년 백제의 신라 공격은 의자왕의 질병과 의사 장원창의 왕진 요청 거부가 중요하게 작용했던 결과라고 할 수 있다. Tang China(618-907), which inherited the medical system of the preceding Sui China(589-618), attempted to reorganize it by absorbing various medical traditions which were then monopolized by hereditary medical families. The hereditary remedies and knowledge of medical specialists who were employed as government physicians were integrated into the state medical system, and the newly developed remedies were open to public. The development of Banwi (反胃, gastric disorder) remedy using donkey urine was one of the cases demonstrating the success of the early Tang medical system. The remedy, developed through a joint research by the physicians from three prestigious medical families in early Tang, was soon to be known to Baekje. King Uija (r. 641-660) of Bakje, who had been suffered from Banwi, dispatched envoys to Tang to ask to send Jiang Yuan-chang to Baekje in 644. The Baekje court seems to have regarded Jiang, a physician who participated in the development of new Banwi remedy, as the most qualified person to cure King Uija. Tang government, however, could not dispatch Jiang to Baekje as he was then working near Sichuan province, hundreds miles from Chang'an, the capital of Tang. As a result, King Uija missed a chance of being treated with the new remedy. Then Baekje, which had once promised not to attack Shilla by sending a prince to Tang, resumed invasion of Shilla in 645, spoiling Emperor Taizong's (r. 626-649) plan to mobilize Baekje's army in his campaign against Goguryeo. As the aftermath of this incident, the relation between Baekje and Tang was irreversibly deteriorated, while Shilla succeeded to consolidate the Shilla-Tang alliance which led to the fall of Baekje in 660. From the perspective of medical diplomacy between Baekje and Tang during the mid 7th centuries, Tang’s failure to meet Baekje’s request for the medical support might have had a grave effect on the Baekje’s decision to move against the Tang’s interests. Park, Jun-hyoung (Naval Academy / shimani5075@hanmail.net) Seo, Young-kyo (Jungwon University / syk367@naver.com)

설악산국립공원 설악폭포 분비나무와 잣나무 1 m 수고생장 기간 조사

최은비(En-Bi Choi),박준희(Jun-Hui Park),김진원(Jin-Won Kim),김요정(Yojung Kim),서정욱(Jeong-Wook Seo) 국립공원연구원 2021 국립공원연구지 Vol.12 No.2

설악산국립공원 설악폭포에 위치한 아고산대 침엽수인 분비나무와 잣나무의 수고생장 기간을 조사하기 위해 본 연구를 수행하였다. 조사를 위해 분비나무 고사목 2본(SAPPAND01, 02)과 잣나무 고사목 1본(SAPPPKD03)을 선발하였다. 높이별 수고생장 기간을 조사하기 위해 뿌리와 줄기 경계를 기준으로 높이 0, 10, 20, 30, 40, 50, 60, 80, 100 cm에서 디스크를 채취하여 나이테(이하, 연륜) 분석을 실시하였다. 또한 고사연도 분석을 위해 생육중인 분비나무 15본에서 생장편을 채취하여, 연구지를 대표하는 연륜폭연대기를 작성하였다. 연륜 분석 결과, 분비나무인 SAPPAND01과 02의 생육 기간은 각각 102년(1915-2016)과 97년(1918-2014)이었으며, 잣나무인 SAPPPKD03은 62년(1926-1987)이었다. SAPPAND01과 02의 고사 시기는 각각 2016년 가을-2017년 봄과 2015년 여름-가을이었으며, SAPPPKD03의 고사 시기는 1987년 가을-1988년 봄이었다. 100 cm까지 수고생장을 하는데 소요되는 기간은 SAPPAND01이 41년으로 가장 길었으며, SAPPAND02와 SAPPPKD03은 각각 17년과 18년으로 조사되어 수종보다는 개체 간 차이가 큰 것으로 확인되었다. 하지만, 대상목 모두에서 수고 20 cm 전후까지 생장하는데 소요되는 기간은 공통적으로 긴 것으로 나타났다. 본 결과는 향후 우리나라 아고산대 침엽수 수령조사의 정확성을 향상 시키는데 중요한 기초자료가 될 것이다. This study aimed at investigating the height-growth duration of Abies nephrolepis and Pinus koraiensis which are the tree species growing in the subalpine area at Seorak Falls of the Seoraksan National Park. For the study, two dead Abies nephrolepis (SAPPAND01, 02) and one dead Pinus koraiensis were selected. To investigate the height-growth duration, 9 disks were collected at the height of 0, 10, 20, 30, 40, 50, 60, 80, 100 cm height from the collar to upward from the sample trees, and then their ring-width were measured. The site master chronology used to the reference to date the death years of the sampled trees was established using the increment cores from 15 living Abies nephrolepis. Through the tree-ring analysis, the ages of SAPPAND01 and 02, and SAPPPKD03 were verified 102 (1915-2016), 97 (1918-2014), and 62 years (1926-1987) years, respectively. The death seasons and years of SAPPAND01 and 02, and SAPPPKD03 were autumn in 2016 - spring in 2017, summer - autumn in 2015, and autumn in 1987 and spring in 1988, respectively. The height-growth durations up to 100 cm from the collars of SAPPAND01 and 02 and SAPPPKD03 were -41, 17, and 18 years, respectively, so that it was verified that the height-growth duration was not changing depending on tree species but individual trees. During the juvenile periods growing up to approximately 20 cm from the collar, however, all sample trees showed relatively taking long times. All results obtained from this study would be fundamental data to improve the accuracy of examining the age of conifers in the subalpine areas.

관상동맥 누공에 의한 급성 심근 경색 1예

서유승,최재웅,송창섭,조용범,양진수,박준섭,정인수 대한내과학회 2003 대한내과학회지 Vol.65 No.2

관상동맥 동정맥루 기형은 매우 드문 질환으로 치료가 불필요한 경우가 대부분이나 coronary steal 현상으로 인해 증상이 발생하거나 합병증이 발생한 환자에 대해선 치료를 요한다. 최근에는 시술에 적합한 누공을 가진 선택된 환자군을 대상으로 카테터를 이용한 중재적 시술이 시행되어 수술적 치료와 유사한 결과를 얻고 있다. 저자들은 젊은 남자에서 관상동맥 동정맥루 기형과 동반된 급성 심근 경색증을 진단하여 비 수술적 방법인 카테타 코일 색전술로 성공적 치료 후 증상 및 심근 재관류에 호전을 보인 증례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. We report a case of coronary fistula between the left anterior descending and main pulmonary artery complicating acute non-Q wave myocardial infarction. A 27-year-old man visited emergency department because of severe chest pain lasting two hours. The electrocardiogram showed ST segment elevation in precordial leads V3~6. Cardiac enzymes were as follows;CK-MB:36.44 IU/L T-T:0.489 ng/mL, CPK:542 IU/L, and LDH:475 IU/L. The thallium-201 dipyridamole stress perfusion scan showed perfusion defect and reversed redistribution in the anteroseptal wall. The coronary angiogram revealed coronary artery fistula between the proximal left anterior descending artery and main pulmonary artery without significant stenoses of coronary arteries. The result of ergonovine test was negative. After micro-coil embolization to the coronary fistula, symptoms were improved. Follow-up thallium-201 scan showed normalized blood flow in the left anteroseptal wall.

탄소섬유 적층혼성부재의 계면수 변화에 따른 축 압궤 특성

서현경,박준우,양용준,황우채,양인영 朝鮮大學校 機械技術硏究所 2007 機械技術硏究 Vol.10 No.1

알루미늄과 CFRP는 대표적인 경량화 재료이다. 알루미늄 부재는 안정적인 소성 변형에 의해 에너지를 흡수하며, CFRP 부재는 비강성과 비강도가 우수하고 불안정한 취성파괴로 인해 에너지를 흡수한다. 이러한 각각 알루미늄과 CFRP 부재의 압궤 특성을 기초로 두 재 료의 결합에 의해 서로의 장점에 대한 시너지 효과를 얻기 위해 혼성구조부재를 제작하였다. 본 연구에서는 알루미늄 부재의 외측을 CFRP로 강화시킨 혼성구조부채를 제작하여 CFRP의 계면수 변화에 따른 축 방향 준정적 압궤실험을 행하여 사각 및 원형 단변 모형의 혼성구조부재의 압궤 특성을 조사하였다. 실험 결과 혼성구조부재는 내부의 알루미늄 부재의 연성 성질 때문에 CFRP 부재의 불안정한 취성 파괴를 보완하여 비교적 안정적인 압궤 모드를 보였다. 하지만 혼성구조부재는 계면수 변화에 대해 에너지 흡수성과 압궤 모드는 별다른 영향을 보이지 않았다. The aluminum or CFRP is representative of light-weight materials. The aluminum tubes absorb energy by stable plastic deformation and the CFRP tubes absorbs energy by unstable brittle failure with higher specific strength and stiffness. Based on the respective collapse characteristics of aluminum and CFRP tubes, the aluminum CFRP compound tubes were manufactured to get a synergy effect when the aluminum CFRP tubes were combined with the advantages of each tube. This paper is to investigate the collapse characteristics of square or circular shaped aluminum CFRP compound tubes subjected to quasi-static axial collapse tests which were conducted by changing the stacking conditions. Test results showed that the collapse of the aluminum CFRP compound tubes complemented unstable brittle failure of the CFRP tube due to the ductile characteristics of the inner aluminum tube. It turned out that interlaminar numbers of aluminum CFRP compound tubes have no influence on the energy absorption and collapse modes of the tubes.

월악산 잣나무 및 화백나무 형성층의 계절적 활동과 적산온도와의 관계

박준희, 강현정, 이해진, 서정욱 충북대학교 농업과학기술연구소 2022 農業科學硏究 Vol.38 No.2

The current study was conducted to investigate (1) the duration of cambial activity and (2) the effect of degree days on the initiation of cambial activity of the Pinus koraiensis (PK) and Chamaecy- paris picifera (CP) planted in Mt. Worak. In addition, the differences of the seasonal cambial activities according to the diameter were also investigated using C. picifera with a diameter of 30 cm (CPL) and 15 cm (CPS), which were planted in the same year. The cambium samples were weekly collected using a mini-borer (Ø 2 mm), so called Traphor, between April and October in 2017. The results obtained are as follow. The initiation of the cambial activity of CP (April 21-28) were slightly earlier than PK (April 21). The species with the longest cambial activity was CPS (147.2±12.1 days), followed by PK (141.6±9.8 days) and CPL (139±12.1 days). The degree days inducing the initiation of the cambial activ- ity for PK and CP were 180.5 and 180.5-242.8, respectively.

EXAFS 법에 의한 Cu_2S 의 원자구조에 관한 연구

박종윤,박준서,이덕원 성균관대학교 기초과학연구소 1989 論文集 Vol.40 No.2

P-형 반도체인 Cu_2S 결정을 두 개의 온도상에 대해 K-흡수 스펙트럼을 수백 eV까지 확장시켜 EXAFS(Extended X-ray Absorption Fine Structure)를 측정하였다. γ-Cu_2S (110℃이하)와 β-Cu_2S(110℃∼470℃)의 구조는 각각 사방정계 구조와 육방정계 구조이다. 분석 방법으로는B.K. Teo, P.A. Lee가 계산한 배면산란 진폭(Backscattering Amplitude), 배면산란으로 인한 위상변위(Backscattering Phase Shift), 중심원자에 의한 위상 변위값(Central Atom Phase Shift)를 이용한 curve fitting method를 사용하였으며, γ-Cu_2S와 β-Cu_2S의 최인접 원자간 거리 (bond-length)는 각각 2.34Å와 2.31Å이었다. 본 실험결과에 따르면 Cu_2S가 상전위(phase transition)함에 따라 최인접 원자간 거리가 변화하지 않는 대부분의 금속이나 반도체와 달리 Cu_2S의 최인접 원자간 거리가 상전위에 따라 변화하였다. The EXAFS cf γ-Cu_2S and β-Cu_2S was measured at the Cu K-absorption edge. The EXAFS was analyzed with curve-fitting method by using backscattering amplitude, backscattering phase shift, and central atom phase shift, which was calculated by B.K. Teo and P.A. Lee. It turned out that the nearest-neighbor-distances(Cu-S) of γ-Cu_2S and β-Cu_2S were 2.34Å and 2.31Å, respectively. XRD(X-Ray Diffraction) was also measured. The structures of γ-Cu_2S and β-Cu_2S were confirmed to be of orthorhombic and hexagonal structure, respectively.

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.

경호상황에서 태권도기법의 적용방법에 관한 연구

박준석,서민학 龍仁大學校 武道硏究所 2004 武道硏究所誌 Vol.15 No.1

This study shows how to apply Taekwondo as a Protectional Martial Art Generally every learning territory is divided into cultural and social science and natural science. In the same manner, the study of guarding should be broken into parts so as to make the most of guarding characteristics. I think that Protection Martial Art will develop in learning because it can motivate Taekwondo participants to study it. I will attempt to show a developing study of Taekwondo as a Protection Martial Art. A Guard is a final method in which deals with each kind of threats. The timing, the place and the way of attempt to inflict an injury is decided by the attactor. The situation of attact is also has many variables. If there isn't a Guard Martial Art or the bodyguard is irresolute, it is difficult to control the attactor. Therefore, the ultimate aim of Protection Martial Art is not only to protect a guarded person from danger through complete training, but also facing an attact and controling it effectively. In order to insure the guarded person's life from the harmer, the bodyguard has to perform his duty from a high degree of training. So training in Protection Martial Art is a necessary condition. When the bodyguard faces an attact and deals with it, he has to grasp and meet the situation - the environment, the direction and the way of attact. Also recognize the a kind of weapon, the attactor's skill and ability and so on. A high degree of guard technics and Guard Martial Art is essential to face and deal with an attact. Owing to establish Protection Martial Art systematically, this shows how to apply Taekwondo training technics to Protection Martial Art and how to deal with a situation of guarding in the event of attact by using basic technics from Taekwondo. First, by studying the system of Protection Martial Art based on Taekwondo, I developed Taekwondo training technics as a Protection Martial Art. Second, "Stance posture" should be neat and sharp. I intend to show the posture-"Parallel Stance"- which is easy to offend and defend in every direction. Moreover it is more developed than it was. Third, I show a desirable "Stance posture" as a guard's position, so that the guard can deal with the dangerous situation promptly and properly. Fourth, I try to show the way how to control an accidental occurance by using a based action and an applied action from Taekwondo as a guard technic. Therefore, I think that the system of Protection Martial Art based on Taekwondo should be studied and Taekwondo should be established as a Protectional martial art. Training Taekwondo as a Protectional martial art enables one to handle any unexpected situation by mastering its theory and basic skills. I consider that we should practice Taekwondo technics through a real model to deal with various dangerous situations.

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.